WO2013047457A1

WO2013047457A1 - Method for manufacturing display device, and display device

Info

Publication number: WO2013047457A1
Application number: PCT/JP2012/074437
Authority: WO
Inventors: 庄治岡崎; 通園田; 宏充勝井; 哲憲田中
Original assignee: シャープ株式会社
Priority date: 2011-09-30
Filing date: 2012-09-24
Publication date: 2013-04-04
Also published as: TW201320429A

Abstract

An a-ITO layer (112) is formed above a reflection electrode layer (111) and the layers are etched together; the a-ITO layer (112) is then converted to a p-ITO layer (114); and the difference in etching resistance between the p-ITO layer (114) and a transparent electrode layer formed above the p-ITO layer is used to layer the transparent electrode layer and to vary the thickness of the transparent electrode layer (121) between subpixels (71R, 71G, 71B).

Description

Display device manufacturing method and display device

The present invention relates to a method for manufacturing a display device in which a transparent electrode layer is laminated on a reflective electrode layer in each sub-pixel, and the total film thickness of the transparent electrode layer is different between sub-pixels having different display colors, and It is related with such a display apparatus.

In recent years, flat panel displays have been used in various products and fields, and further flat panel displays are required to have larger sizes, higher image quality, and lower power consumption.

Under such circumstances, an organic EL display device including an organic EL element using electroluminescence of an organic material (Electro-Luminescence: hereinafter referred to as “EL”) is an all-solid-state type, driven at a low voltage, As a flat panel display excellent in terms of high-speed response, self-luminous property, wide viewing angle characteristics, etc., it is attracting a lot of attention.

An organic EL display device has, for example, a configuration in which an organic EL element electrically connected to a TFT is provided on a substrate made of a glass substrate provided with a TFT (Thin Film Transistor). .

The organic EL element is a light-emitting element that can emit light with high luminance by low-voltage direct current drive, and has a structure in which a first electrode, an organic EL layer, and a second electrode are stacked in this order.

As a method for full-coloring an organic EL display device using such an organic EL element, for example, (1) an organic EL element that emits red (R), green (G), and blue (B) is used as a sub-color. A method of arranging pixels on a substrate and (2) a method of selecting a light emission color in each sub-pixel by combining a white light emitting organic EL element and a color filter are known.

Recently, in these methods, methods for improving the chromaticity of light emission and light emission efficiency by the microcavity effect have been proposed (for example, see Patent Documents 1 and 2).

The microcavity is a phenomenon in which emitted light undergoes multiple reflections between the anode and the cathode and resonates, resulting in a steep emission spectrum and amplification of the emission intensity at the peak wavelength.

The microcavity effect can be obtained, for example, by optimally designing the reflectance and film thickness of the anode and cathode, the layer thickness of the organic layer, and the like.

As a method for introducing such a resonance structure, that is, a microcavity structure into an organic EL element, for example, a method of changing the optical path length of the organic EL element in each sub-pixel for each emission color is known.

As a method of changing the optical path length of the organic EL element in each sub-pixel for each emission color, a method of laminating an organic EL layer including a light emitting layer and a transparent electrode layer between a reflective electrode and a semitransparent electrode can be mentioned. .

That is, for example, in the case of a top emission type organic EL element, the anode has a laminated structure of a reflective electrode layer and a transparent electrode layer, and the film thickness of the transparent electrode layer on the reflective electrode layer of the anode is changed for each subpixel. A method is mentioned.

In the case of a top emission type organic EL element, the anode has a laminated structure of a reflective electrode layer and a transparent electrode layer as described above, and after the organic EL layer is appropriately laminated, the cathode is made into a thin film, for example, as a semitransparent electrode. By using translucent silver or the like, a microcavity structure can be introduced into the organic EL element.

When the microcavity structure is introduced into the organic EL element as described above, the spectrum of light emitted from the light emitting layer and emitted through the cathode becomes steeper than when the organic EL element does not have the microcavity structure. The intensity of light emitted to the front is greatly increased.

Patent Documents

1 and 2 disclose an organic EL display device in which a microcavity structure is introduced into an organic EL element by laminating transparent electrode layers of the same material while changing the number of laminated layers for each sub-pixel.

Japanese Patent Publication “Japanese Patent Laid-Open No. 2007-280677 (published on Oct. 25, 2007)” Japanese Patent Publication “Japanese Patent Laid-Open No. 2005-116516 (published April 28, 2005)” Japanese Patent Publication “JP 2009-129604 A” (published on June 11, 2009)

However, in the organic EL display device that adjusts the emission color by changing the microcavity effect by changing the film thickness of the transparent electrode layer as described above, the film thickness of the transparent electrode layer is appropriately set for each sub-pixel of each color. The method of changing to is not known so far.

Note that Patent Document 1 does not disclose a method for changing the film thickness of the transparent electrode for each sub-pixel of each color.

On the other hand, Patent Document 2 discloses the following method as a method of changing the film thickness of the transparent electrode for each sub-pixel of each color using the same material for the transparent electrode layer to be laminated.

First, transparent electrode layers and resist patterns are alternately laminated on the reflective electrode layer while changing the subpixels on which the resist pattern is laminated in the order of B → G → R.

Next, after a resist pattern is stacked on the R subpixel, the uppermost transparent electrode layer is etched using the resist pattern of the R subpixel as a mask, and when the resist pattern of the G subpixel is exposed, Using the resist pattern of the subpixel as a mask, the second transparent electrode layer from the top is etched.

After that, when the resist pattern of the B sub-pixel is exposed, all the transparent electrode layers are patterned by etching the transparent electrode layer of the lowermost layer using the resist pattern of the R, G, and B sub-pixels as a mask. To do.

Finally, the reflective electrode layer is etched and patterned using the resist pattern of the R, G, and B subpixels as a mask.

However, in Patent Document 2, since the transparent electrode layer is laminated on the resist pattern, if the adhesiveness between the resist and the transparent electrode layer is not sufficient, film peeling of the transparent electrode layer occurs during the processing, resulting in a pattern defect or a process. There is a risk of contamination.

In addition, if a substrate with a resist layer is put into the sputtering apparatus, foreign substances such as dust adhere to it, which may reduce the yield, and defects, film thickness unevenness, film quality unevenness (in-plane distribution of optical properties) ).

In addition, when a transparent electrode is laminated on a resist pattern as described in Patent Document 2, if the thickness of the resist pattern is thick, a portion that is shaded by the resist pattern becomes large. There is a possibility that defects may occur in the layer or unevenness in film thickness may occur. For this reason, it is difficult to set the transparent electrode layer to an optimum film thickness for each color sub-pixel, and the sub-pixel cannot be formed with a high-definition pattern.

For this reason, it is difficult to change the film thickness of the transparent electrode for each sub-pixel of each color by simply laminating the transparent electrode layer.

As a method of changing the film thickness of the transparent electrode for each sub-pixel of each color, for example, the following method can be considered.

FIGS. 13A to 13F are cross-sectional views showing an example of a method for changing the film thickness of the transparent electrode layer on the reflective electrode layer of the anode for each sub-pixel in the order of steps.

Hereinafter, a method for changing the thickness of the transparent electrode layer on the reflective electrode layer of the anode for each sub-pixel will be described with reference to FIGS. 13A to 13F.

First, as shown in FIG. 13A, a reflective electrode layer 302 made of a reflective electrode material such as silver (Ag) is formed on a support substrate 301 by a sputtering method or the like.

Next, a resist pattern (not shown) is formed by photolithography on each of the sub-pixels of each color on the reflective electrode layer 302. After etching the reflective electrode layer 302 using the resist pattern as a mask, the resist pattern is removed from the resist. Remove and clean with liquid.

Thereby, as shown in FIG. 13B, the reflective electrode layer 302 is patterned so as to be separated for each sub-pixel of each color.

Next, as shown in FIG. 13C, on the reflective electrode layer 302, for example, an IZO (Indium Zinc Oxide) film is formed as a transparent electrode layer to form an IZO layer 303. A photoresist 311 is formed only on the R subpixel by lithography.

Next, as shown in FIG. 13D, the exposed IZO layer 303 is removed by etching with oxalic acid, and then the photoresist 311 is peeled off, so that only the first sub-pixel of the R is removed. A patterned IZO layer 303 is formed as the IZO layer.

Thereafter, as shown in FIG. 13E, an IZO film is formed again so as to cover the IZO layer 303 of the R subpixel and the reflective electrode layer 302 of the G and B subpixels, and the IZO layer 304 is formed. Further, a photoresist 312 is formed only on the R and G subpixels by photolithography.

Thereafter, as shown in FIG. 13F, the IZO layer 304 is etched with oxalic acid using the photoresist 312 as a mask, and the photoresist 312 is peeled off to form a second IZO layer on the sub-pixels R and G. Then, a patterned IZO layer 304 is formed.

Thus, in order to obtain the microcavity effect, if the number of transparent electrode layers stacked is changed for each sub-pixel, for example, when the sub-pixel is composed of R, G, and B sub-pixels, at least three photo Lithography, etching, and resist stripping are required.

In other words, in order to change the film thickness of the transparent electrode layer on the reflective electrode layer of the anode for each subpixel, as shown in FIGS. 13A to 13F, photolithography is required three times. . Including the patterning of the reflective electrode layer, photolithography is required four times. Further, in FIG. 13F, when a transparent electrode layer is further formed on the B pixel, photolithography is required once more.

Therefore, in order to obtain the microcavity effect as described above, if the transparent electrode layer of the same material is used and the thickness of the electrode is changed for each sub-pixel, at least three times (photolithography for patterning of the reflective electrode layer). If this is included, an apparatus for performing photolithography, etching, and resist stripping at least four times is required. For this reason, the number of photolithography apparatuses (photo process apparatuses) for performing the above-described processing required in the production line increases.

Photolithography requires expensive equipment and materials. Therefore, if the thickness of the electrode is changed for each sub-pixel as described above, it leads to an increase in the cost of the entire device and an increase in footprint.

Furthermore, since photolithography requires development processing and baking processing for a certain time, it is difficult to shorten the processing tact.

Therefore, it is desirable that the number of times of photolithography is as small as possible.

Also, as described above, when the photoresist is repeatedly peeled and baked, if the number of repetitions increases, the surface of the reflective electrode layer is roughened or oxidized, and the reflection efficiency is lowered. In addition, there is a possibility that an inter-electrode leak occurs due to the rough surface of the reflective electrode, resulting in a pixel defect.

Also, depending on the type of the reflective electrode material, if the reflective electrode layer is in an exposed state (that is, an exposed state), for example, if it is irradiated with ultraviolet rays in order to improve the wettability of the resist, it will oxidize and the reflection characteristics will decrease. Or the solvent resistance is low and the solvent may penetrate. For this reason, when such a reflective electrode layer consists of such a reflective electrode material, it is not desirable that the reflective electrode layer is exposed.

For this reason, if a transparent electrode layer is to be laminated on the reflective electrode layer of each sub-pixel, photolithography for this purpose is required, and the number of photolithography increases further.

In Patent Document 3, ITO having different crystallinity is laminated to form a patterned ITO on the patterned reflective electrode layer and patterned, and then amorphous ITO is laminated. Thus, a method of changing the film thickness of the transparent electrode layer for each sub-pixel by photolithography twice is disclosed. That is, in Patent Document 3, if the patterning of the reflective electrode layer is included, the number of times of photolithography is three.

However, in Patent Document 3, an ITO having crystallinity is formed and patterned on the first and third subpixels, and then amorphous ITO is stacked on the first subpixel and the second subpixel. Thus, the film thickness of the transparent electrode layer is changed for each sub-pixel by patterning.

That is, in Patent Document 3, a transparent electrode layer pattern having the same film thickness is formed on two sub-pixels each time photolithography is performed, and the sub-pixel that forms the transparent electrode layer pattern is changed for each photolithography. The number of lithography is reduced, and for this purpose, the ITO having crystallinity is etched to form a pattern of transparent electrode layers having the same film thickness on the two sub-pixels.

For this reason, in Patent Document 3, the optical path length of each sub-pixel is determined by the combination of the film thicknesses of the two transparent electrode layers. Therefore, there are restrictions on the setting of the optical path length, and it is difficult to arbitrarily change the optical path length.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a transparent electrode layer on a reflective electrode layer in each sub-pixel, and a reflective electrode between sub-pixels having different display colors. In addition to providing a practical display device manufacturing method capable of arbitrarily changing the film thickness of the transparent electrode layer on the layer, the number of times of photolithography is reduced. A further object of the present invention is to provide a display device in which the transparent electrode layer has a different film thickness for each sub-pixel having a different display color and can be manufactured by a practical method.

In order to solve the above-described problem, a manufacturing method of a display device according to the present invention includes a reflective electrode layer and a reflective electrode layer on one electrode of a pair of electrodes that form an electric field in each subpixel. A plurality of transparent electrode layers are formed on the reflective electrode layer in at least one sub-pixel, and the transparent electrode layer is formed between sub-pixels having different display colors. And a first transparent electrode layer made of an amorphous transparent electrode material in an upper layer than the reflective electrode layer. A first transparent electrode layer forming step for forming a film, and a pattern pattern in which the first transparent electrode layer made of the amorphous transparent electrode material and the reflective electrode layer are collectively etched and patterned by photolithography. A first transparent electrode layer made of the amorphous transparent electrode material patterned in the patterning step and converted into a first transparent electrode layer made of a polycrystalline transparent electrode material. Transparent electrode layer crystallization step, and transparent electrode material having lower etching resistance than first transparent electrode layer made of polycrystalline transparent electrode material on first transparent electrode layer made of polycrystalline transparent electrode material And a second transparent electrode layer stacking step of selectively etching and patterning the second transparent electrode layer by photolithography.

As described above, according to the present invention, the first transparent electrode layer made of an amorphous transparent electrode material is formed above the reflective electrode layer, and the reflective electrode layer and the amorphous transparent electrode material are formed. The first transparent electrode layer made of the polycrystalline transparent electrode material is formed on the reflective electrode layer without increasing the number of times of photolithography by collectively etching the first transparent electrode layer made of Can be stacked.

Further, according to the above method, the first transparent electrode layer made of the amorphous transparent electrode material is converted into the first transparent electrode layer made of the polycrystalline transparent electrode material, and the film is formed thereon. A transparent electrode layer is laminated | stacked using the difference in etching tolerance with a 2nd transparent electrode layer.

According to the above method, the first transparent electrode layer made of a polycrystalline transparent electrode material having a higher etching resistance than the second transparent electrode layer is formed below the second transparent electrode layer. As a result of being laminated, the lower first transparent electrode layer is not etched when the upper second transparent electrode layer is etched. In addition, according to the above method, the first transparent electrode layer made of the polycrystalline transparent electrode material is laminated on each sub-pixel before the second transparent electrode layer is formed. The second transparent electrode layer can be laminated on any subpixel.

For this reason, according to the above method, the transparent electrode layer is formed on the reflective electrode layer of each subpixel, and photolithography necessary for changing the total film thickness of the transparent electrode layer in each subpixel. The total film thickness of the transparent electrode layer can be arbitrarily changed for each sub-pixel by performing photolithography twice. Moreover, according to said method, the frequency | count of photolithography can be restrained to 3 times also including the etching of a reflective electrode layer.

Therefore, according to the above method, even if the number of times of photolithography is reduced as described above, the film thickness of the second transparent electrode layer in an arbitrary subpixel is set to the second transparent electrode in another subpixel. It can be set independently of the film thickness of the layer.

That is, as in Patent Document 3, an ITO layer having crystallinity is separately formed and patterned in order to stack the transparent electrode layers, and the pattern of the transparent electrode layer having the same film thickness is formed on two sub-pixels every time photolithography is performed. Even if the transparent electrode layer is not formed, a transparent electrode layer is formed on the reflective electrode layer of each sub-pixel in two photolithography, and the transparent electrode layer on the reflective electrode layer is different for each sub-pixel having a different display color. Electrodes with different total film thicknesses can be formed.

Therefore, according to the above method, the optical path length in each sub-pixel can be arbitrarily and easily adjusted without being restricted by the optical path length as in Patent Document 3. Therefore, according to the above method, the film thickness of the transparent electrode layer on the reflective electrode layer can be arbitrarily changed for each sub-pixel having a different display color by a smaller number of photolithography than the conventional method.

As a result, the cost can be reduced and the footprint can be reduced as compared with the conventional case.

In addition, in the conventional method, since the photoresist stripping and baking processes are increased, the surface of the reflective electrode layer is roughened or oxidized, resulting in a decrease in reflection efficiency, or leakage between electrodes due to the rough surface of the reflective electrode layer. There was a risk of pixel defects.

However, according to the above method, the number of times of exposure, development, resist stripping and the like can be reduced, so there is no such fear. Further, the processing tact can be shortened.

However, according to the above method, the polycrystalline transparent electrode layer is formed on the reflective electrode layer in each sub-pixel as described above at an early stage in the manufacturing process. It can protect from the said factor which may impair the quality of a reflective electrode layer.

In Patent Document 3, after patterning the reflective electrode layer, the first and third sub-pixels are formed and patterned with crystalline ITO.

Crystalline ITO has high solubility in the etching solution used for etching the reflective electrode layer. For this reason, when an ITO layer having crystallinity is directly formed on the reflective electrode layer and patterned by photolithography, the reflective electrode layer may not be tapered.

However, according to the above method, by forming the first transparent electrode layer made of an amorphous transparent electrode material, patterning the reflective electrode layer together, and then converting it to a polycrystalline transparent electrode layer, Such a problem does not occur.

Thus, according to the above method, the transparent electrode layer is laminated on the reflective electrode layer in each subpixel, and the film thickness of the transparent electrode layer on the reflective electrode layer is changed between the subpixels having different display colors. In addition to providing a practical display device manufacturing method that can be arbitrarily changed, the number of times of photolithography can be reduced.

Further, in order to solve the above-described problem, in the display device according to the present invention, one of the pair of electrodes that form an electric field in each subpixel has a reflective electrode layer and the reflective electrode layer on the reflective electrode layer. At least one transparent electrode layer formed, and a plurality of the transparent electrode layers are formed on the reflective electrode layer in at least one sub-pixel, and the transparent electrode layer is formed between sub-pixels having different display colors. It is a display device with different overall film thickness, wherein the plurality of transparent electrode layers have different compositions, and the etching resistance of the lower transparent electrode layer is higher than the etching resistance of the upper transparent electrode layer. It is a feature.

Such a display device etches the lower transparent electrode layer and the upper transparent electrode layer without converting the transparent electrode layer made of the amorphous transparent electrode material into the transparent electrode layer made of the polycrystalline transparent electrode material. The transparent electrode layers can be stacked using the difference in etching selectivity due to the difference in resistance.

For this reason, the optical path length in each sub-pixel can be arbitrarily and easily adjusted with a short processing tact as compared with the case where transparent electrode layers made of the same transparent electrode material are stacked as in the prior art.

Therefore, according to the present invention, it is possible to provide a display device that can be manufactured by a practical method while the thickness of the transparent electrode layer is different for each sub-pixel having a different display color.

As described above, in the method for manufacturing a display device according to the present invention, the first transparent electrode layer made of an amorphous transparent electrode material is formed above the reflective electrode layer, and the reflective electrode layer and the non-reflective electrode layer are formed. The first transparent electrode layer made of a crystalline transparent electrode material is etched together.

For this reason, according to the manufacturing method, the first transparent electrode layer made of the polycrystalline transparent electrode material can be laminated on the reflective electrode layer without increasing the number of times of photolithography.

In the method for manufacturing a display device according to the present invention, the first transparent electrode layer made of an amorphous transparent electrode material is converted into a first transparent electrode layer made of a polycrystalline transparent electrode material, and the first transparent electrode layer is formed thereon. A transparent electrode layer is laminated | stacked using the difference in etching tolerance with the 2nd transparent electrode layer formed into a film.

According to the above manufacturing method, the first transparent electrode made of a polycrystalline transparent electrode material, which has a higher etching resistance than the second transparent electrode layer, is formed below the second transparent electrode layer. By laminating the layers, the lower first transparent electrode layer is not etched when the upper second transparent electrode layer is etched. In addition, according to the above manufacturing method, the first transparent electrode layer made of the polycrystalline transparent electrode material is laminated on each sub-pixel before the second transparent electrode layer is formed. Thus, the second transparent electrode layer can be laminated on any sub-pixel.

For this reason, according to the above manufacturing method, the transparent electrode layer is formed on the reflective electrode layer of each sub-pixel, and the photo required for changing the total film thickness of the transparent electrode layer in each sub-pixel. As the number of times of lithography, the total film thickness of the transparent electrode layer can be arbitrarily changed for each sub-pixel by photolithography. Moreover, according to said manufacturing method, the frequency | count of photolithography can be restrained to 3 times also including the etching of a reflective electrode layer.

Therefore, according to the above manufacturing method, even if the number of times of photolithography is reduced as described above, the film thickness of the second transparent electrode layer in an arbitrary subpixel is set to the second transparent electrode in another subpixel. It can be set independently of the film thickness of the electrode layer.

Therefore, according to the above manufacturing method, the optical path length in each sub-pixel can be arbitrarily and easily adjusted without being restricted by the optical path length as in Patent Document 3. Therefore, according to said manufacturing method, the film thickness of the transparent electrode layer on a reflective electrode layer can be arbitrarily changed for every sub pixel from which a display color differs by the photolithography of the frequency | count of less than before.

Further, as described above, the display device according to the present invention includes a plurality of transparent electrode layers on the reflective electrode layer, and the total film thickness of the transparent electrode layer is different for each sub-pixel having a different display color. In the different display devices, the plurality of transparent electrode layers have different compositions, and the etching resistance of the lower transparent electrode layer is higher than the etching resistance of the upper transparent electrode layer.

(A)-(i) is sectional drawing which shows an example of the manufacturing method of the 1st electrode in the top emission type organic electroluminescence display concerning Embodiment 1 in order of a process. 1 is an exploded cross-sectional view illustrating a schematic configuration of a main part of an organic EL display device according to a first embodiment. 3 is a plan view showing a schematic configuration of a support substrate in the organic EL display device according to Embodiment 1. FIG. It is a top view which shows the structure of the principal part of the display area in the support substrate shown in FIG. FIG. 5 is a cross-sectional view showing a schematic configuration of the organic EL display panel when the organic EL display panel according to the first embodiment is cut along line AA shown in FIG. FIG. 3 is a schematic diagram illustrating an image display method of the organic EL display device according to the first embodiment. 3 is a flowchart illustrating an example of a manufacturing process of the organic EL display device according to the first embodiment in the order of processes. 3 is a flowchart illustrating an example of a manufacturing process of the organic EL layer according to the first embodiment in order of processes. (A) * (b) is a figure which shows typically schematic structure of a 1st electrode when producing an edge cover on the 1st electrode shown to (i) of FIG. 1, (a) is sectional drawing. (B) is a plan view. (A)-(h) is sectional drawing which shows an example of the process from preparation of the 1st electrode in the top emission type organic EL display apparatus 00 concerning Embodiment 2 to preparation of an edge cover in order of a process. FIG. 5 is a cross-sectional view illustrating a schematic configuration of an organic EL display panel according to a third embodiment. It is a flowchart which shows an example of the manufacturing process of the organic electroluminescent layer shown in FIG. (A)-(f) is sectional drawing which shows an example of the method of changing the total film thickness of the transparent electrode layer on the reflective electrode layer of an anode for every sub pixel in order of a process.

Hereinafter, an embodiment of the present invention will be described in detail.

[Embodiment 1]
This embodiment will be described below with reference to FIGS. 1A to 1I to 9A and 9B.

<Schematic configuration of organic EL display device>
First, a schematic configuration of the organic EL display device will be described.

FIG. 2 is an exploded sectional view showing a schematic configuration of a main part of the organic EL display device 100 according to the present embodiment.

As shown in FIG. 2, the organic EL display device 100 according to the present embodiment includes a pixel unit 101 and a circuit unit 102.

The pixel unit 101 is composed of an organic EL display panel 1 (display panel). The circuit unit 102 includes a circuit board provided with a drive circuit for driving the organic EL display device 100, an IC (Integrated Circuits) chip, and the like.

The organic EL display panel 1 has a configuration in which an organic EL element 20, a sealing resin layer 41, a filling resin layer 42, and a sealing substrate 50 are provided in this order on a support substrate 10 (deposition substrate, TFT substrate). have.

The support substrate 10 is made of a semiconductor substrate such as a TFT substrate. For example, the support substrate 10 has a structure in which a thin film transistor (TFT) 12 (see FIG. 5) is provided as an active element (drive element) on an insulating substrate 11. Have.

The organic EL element 20 is connected to the TFT 12. On the organic EL element 20, a filling resin layer 42 having adhesiveness containing a desiccant is formed. The filling resin constituting the filling resin layer 42 is filled in a space surrounded by the support substrate 10, the sealing substrate 50, and the sealing resin layer 41.

The organic EL display device 100 may be a bottom emission type that emits light from the support substrate 10 side, or a top emission type that emits light from the sealing substrate 50 side.

As the base substrate used for the support substrate 10 and the sealing substrate 50, for example, glass or plastic can be used. As an example, for example, a glass substrate such as an alkali-free glass substrate can be used.

However, the present invention is not limited to this, and an opaque material such as a metal plate can also be used as the substrate on the side that does not emit light.

In the case of a top emission type, a substrate on which a CF (Color Filter) layer is formed may be used as the sealing substrate 50. In the case of the bottom emission type, a CF layer may be formed on the support substrate 10 side.

Thus, when the CF layer is used together, the spectrum of the light emitted from the organic EL element 20 can be adjusted by the CF layer.

Hereinafter, in the present embodiment, a case where the organic EL display device 100 is a top emission type will be described as an example. However, the present embodiment is not limited to this, and may be, for example, a bottom emission type as described above.

As shown in FIG. 2, the sealing substrate 50 according to the present embodiment is provided with, for example, a CF layer 52, a BM (Black-Matrix) 53 (see FIG. 5), and the like on an insulating substrate 51. It has a configuration.

The organic EL element 20 includes a sealing resin layer provided in a frame-shaped sealing region L with the support substrate 10 on which the organic EL element 20 is laminated so that the organic EL element 20 is not damaged by moisture or oxygen. By being bonded to the sealing substrate 50 via 41 and the filling resin layer 42, the sealing substrate 50 is sealed between the pair of substrates (the support substrate 10 and the sealing substrate 50).

In the organic EL display panel 1, the organic EL element 20 is sealed between the support substrate 10 and the sealing substrate 50 as described above, thereby preventing oxygen and moisture from entering the organic EL element 20 from the outside. Has been.

Further, outside the frame-shaped sealing region L in the support substrate 10, a terminal portion region R3 in which the electrical wiring terminals 2 (electric connection portions, connection terminals) and the like are formed is provided.

The electrical wiring terminal 2 is a connection terminal to which the connection terminal 103 of the circuit unit 102 is connected, and is formed of a wiring material such as metal.

The circuit unit 102 is provided with wiring such as a flexible film cable, a drive circuit such as a driver, and the like.

As shown in FIG. 2, the circuit unit 102 is connected to the organic EL display panel 1 through an electrical wiring terminal 2 provided in the terminal region R3.

<Configuration of Support Substrate 10>
Here, each area | region in the support substrate 10 including terminal part area | region R3 is demonstrated below with reference to FIG.

FIG. 3 is a plan view showing a schematic configuration of the support substrate 10 in the organic EL display device 100.

As shown in FIG. 3, on one main surface which is an active surface (active element formation surface) of the support substrate 10, a display region R1, a second electrode connection region R2, a terminal region R3, and a frame-shaped seal are formed. A stop region L is provided.

<Display area R1>
The display region R1 (display unit) is provided at the center of the support substrate 10, and is formed in a rectangular shape, for example. In the display region R1, a pixel array including a plurality of sub-pixels 71 (see FIGS. 4 and 5) is formed. The configuration of the display area R1 will be described in detail later.

<Second electrode connection region R2>
The second electrode connection region R2 is a region to which the second electrode 31 (see FIG. 5) in the organic EL element 20 is connected. For example, the second electrode connection region R2 is formed on the outer side of the pair of sides of the pair of the display regions R1 and along the opposite sides.

These connection portions 60 (connection electrodes) are formed in the second electrode connection regions R2. The connection part 60 is a part to which the second electrode 31 is connected, and is formed of a metal material.

<Sealing region L>
As described above, the sealing resin layer 41 for bonding the support substrate 10 and the sealing substrate 50 is formed in the sealing region L.

As shown in FIG. 3, the sealing region L is formed in a frame shape so as to surround the display region R1 and the second electrode connection region R2.

<Terminal part region R3>
As described above, the terminal portion region R3 is a region used for connection between the pixel portion 101 and the circuit portion 102. The terminal region R3 is provided outside the frame-shaped sealing region L along the frame-shaped sealing region L.

Specifically, as shown in FIG. 3, the terminal region R3 is formed outside each second electrode connection region R2 and along each second electrode connection region R2. Further, the terminal region R3 is formed along the opposing sides on the outside of the other pair of sides in the display region R1 where the second electrode connection region R2 is not provided.

Note that the terminal region R3 does not have to exist on all sides, and may be formed concentrated on only one side, for example.

<Configuration of display region R1>
Next, the configuration of the display area R1 will be described.

4 is a plan view showing a configuration of a main part of the display region R1 in the support substrate 10, and FIG. 5 is an organic EL display panel when the organic EL display panel 1 is cut along line AA shown in FIG. 1 is a cross-sectional view showing a schematic configuration of 1. FIG.

As shown in FIGS. 4 and 5, the display region R1 is composed of a plurality of pixels 70 on which the organic EL elements 20 are formed.

Each pixel 70 is composed of a plurality of sub-pixels 71. The organic EL display device 100 is a full-color active matrix organic EL display device. For example, as shown in FIG. 5, a subpixel 71 that emits red (R) light (hereinafter referred to as “subpixel 71R”). ), Sub-pixel 71 that emits light in green (G) (hereinafter referred to as “sub-pixel 71G”), and sub-pixel 71 that emits light in blue (B) (hereinafter referred to as “sub-pixel 71B”). One pixel 70 is constituted by the two sub-pixels 71R, 71G, and 71B.

In the display region R1, sub-pixels 71 of each color composed of the organic EL elements 20 having the emission colors of R, G, and B are arranged in a matrix. In the present embodiment, each of the sub-pixels 71R, 71G, and 71B has one of the X-axis direction (lateral direction) and the Y-axis direction (vertical direction) on the active surface of the support substrate 10 (for example, the X-axis direction). In addition, the sub-pixels 71 having the same emission color are adjacent to each other, and the sub-pixels 71 having different emission colors are adjacent to each other in the other direction (for example, the Y-axis direction).

As shown in FIGS. 4 and 5, a plurality of signal lines 14 (wirings) are arranged in the X-axis direction and the Y-axis direction in the display region R1.

The signal line 14 includes, for example, a plurality of lines for selecting pixels (gate lines), a plurality of lines for writing data (source lines), a plurality of lines for supplying power to the organic EL elements 20 (power supply lines), and the like. ing.

The gate line is laid along, for example, the X-axis direction, and the source line is laid along, for example, the Y-axis direction so as to intersect the gate line.

Further, a gate line driving circuit (not shown) for driving the gate line is connected to the gate line, and a data line driving circuit (not shown) for driving the source line is connected to the source line.

The sub-pixels 71 are arranged in a region surrounded by the signal lines 14. That is, a region surrounded by the signal lines 14 is one sub pixel 71, and a light emitting region 72 of each color is defined for each sub pixel 71.

These signal lines 14 are connected to an external circuit of the circuit unit 102 outside the display region R1. By inputting an electrical signal from the circuit unit 102 to the signal line 14, the organic EL element 20 disposed at the intersection of the signal line 14 can be driven (light emission).

Each of the

subpixels

71R, 71G, and 71B is provided with a TFT 12 connected to the first electrode 21 in the organic EL element 20.

The signal line 14 is connected to the TFT 12 provided in each of the sub-pixels 71. In the case of the active matrix type, each subpixel 71 is provided with at least one TFT 12.

Note that each sub-pixel 71 may further be formed with a capacitor for holding the written voltage and a compensation circuit for compensating for the characteristic variation of the TFT 12.

The emission intensity of each sub-pixel 71 is determined by scanning and selection using the signal line 14 and the TFT 12. The organic EL display device 100 realizes image display by selectively causing the organic EL element 20 to emit light with a desired luminance using the TFT 12.

<Cross-sectional structure of support substrate 10>
As shown in FIGS. 4 and 5, the support substrate 10 includes an insulating substrate 11 as a base substrate.

As shown in FIG. 5, in the display region R <b> 1, the support substrate 10 is formed on a transparent insulating substrate 11 such as a glass substrate, a TFT 12 (switching element) and a signal line 14, an interlayer insulating film 13 (flattening film), an edge The cover 15 and the like are formed.

On the insulating substrate 11, signal lines 14 are provided, and TFTs 12 are provided corresponding to the sub-pixels 71R, 71G, 71B, respectively. The structure of the TFT is conventionally well known. The TFT 12 is manufactured by a known method. Therefore, illustration and description of each layer in the TFT 12 are omitted.

The interlayer insulating film 13 is laminated over the entire area of the insulating substrate 11 on the insulating substrate 11 so as to cover the sub-pixels 71R, 71G, 71B and the signal lines 14.

The first electrode 21 in the organic EL element 20 is formed on the interlayer insulating film 13.

The interlayer insulating film 13 is provided with a contact hole 13 a for electrically connecting the first electrode 21 in the organic EL element 20 to the TFT 12. Thereby, the TFT 12 is electrically connected to the organic EL element 20 through the contact hole 13a.

The edge cover 15 has an end portion (pattern end portion) of the first electrode 21, and an organic EL layer 43 (to be described later) becomes thin or an electric field concentration occurs. This is an insulating layer (barrier) for preventing the electrode 31 from being short-circuited.

The edge cover 15 is formed on the interlayer insulating film 13 so as to cover the end portion (pattern end portion) of the first electrode 21.

The edge cover 15 is provided with

openings

15R, 15G, and 15B for each of the sub-pixels 71R, 71G, and 71B. Thereby, as shown in FIG. 5, the 1st electrode 21 is exposed in the part (opening part 15R * 15G * 15B) without the edge cover 15. As shown in FIG. This exposed portion becomes the light emitting region 72 of each of the sub-pixels 71R, 71G, and 71B.

<Configuration of Organic EL Element 20>
In the present embodiment, a full-color image display is realized as described above by using a light-emitting layer whose emission color is white (W) and introducing a microcavity structure in each sub-pixel 71.

At this time, the spectrum of the light emitted from the organic EL element 20 can be adjusted by the CF layer 52 by using the CF layer 52 together as described above.

The organic EL element 20 is a light emitting element that can emit light with high luminance by low-voltage direct current drive, and the first electrode 21, the organic EL layer 43, and the second electrode 31 are laminated in this order.

The first electrode 21 is a layer having a function of injecting (supplying) holes into the organic EL layer 43. The first electrode 21 is connected to the TFT 12 through the contact hole 13a.

The second electrode 31 is a layer having a function of injecting (supplying) electrons into the organic EL layer 43.

In this way, when the W light emitting layer and the CF layer 52 are combined, a carrier transport layer (hole transport layer, electron transport layer) and a light emitting layer are laminated via the carrier generation layer.

Specifically, between the first electrode 21 and the second electrode 31, as shown in FIG. 5, as the organic EL layer 43, the hole injection layer 22, the hole transport layer are formed from the first electrode 21 side. 23, the first light-emitting layer 24, the electron transport layer 25, the carrier generation layer 26, the hole transport layer 27, the second light-emitting layer 28, the electron transport layer 29, and the electron injection layer 30 are formed in this order. Note that the emission colors of the first emission layer 24 and the second emission layer 28 are different, and W emission is obtained by superimposing these emission colors.

Examples of the combination of the emission colors include a combination of blue light and yellow (more preferably yellow (orange) having a peak intensity in green and red) light, a combination of blue light and yellow light, and the like. In addition, as described later, in the case where W light emission is obtained by superimposing the three light emission colors by stacking the third light emission layer in addition to the first light emission layer 24 and the second light emission layer 28, Can be a combination of red light, blue light, and green light.

In the present embodiment, a blue light emitting layer is formed as the first light emitting layer 24, and an orange light emitting layer is formed as the second light emitting layer 28.

As described above, when the first light emitting layer 24 and the second light emitting layer 28 are stacked as the light emitting layer, the microcavity effect is added to the mixing of the light emitted from the first light emitting layer 24 and the second light emitting layer 28. Light is obtained by the organic EL element 20. Further, by adjusting the light by the CF layer 52 provided on the sealing substrate 50, light having a desired spectrum can be extracted to the outside. In this way, color purity can be increased by combining the W light emitting layer, the microcavity effect, and the CF layer 52.

The hole injection layer 22 is a layer having a function of increasing the efficiency of hole injection from the first electrode 21 to the organic EL layer 43. On the other hand, the electron injection layer 30 is a layer having a function of increasing the efficiency of electron injection from the second electrode 31 to the organic EL layer 43.

The hole transport layer 23 is a layer having a function of increasing the hole transport efficiency to the first light emitting layer 24, and the hole transport layer 27 is a function of increasing the hole transport efficiency to the second light emitting layer 28. It is a layer which has.

On the other hand, the electron transport layer 25 is a layer having a function of increasing the electron transport efficiency to the first light emitting layer 24, and the electron transport layer 29 is a layer having a function of increasing the electron transport efficiency to the second light emitting layer 28. is there.

The first light emitting layer 24 and the second light emitting layer 28 each have a function of emitting light by recombining holes injected from the first electrode 21 side and electrons injected from the second electrode 31 side. Is a layer. The first light emitting layer 24 and the second light emitting layer 28 are each formed of a material having high light emission efficiency, such as a low molecular fluorescent dye or a metal complex.

The carrier generation layer 26 is a layer for supplying electrons to the first light emitting layer 24 side and holes to the second light emitting layer 28 side.

That is, assuming that the hole transport layer, the light-emitting layer, and the electron transport layer are one unit, the unit on the first light-emitting layer 24 side and the unit on the second light-emitting layer 28 side are connected via the carrier generation layer 26. Will be.

As described above, in the organic EL display device 100 in which the W light emitting layer (for example, the first light emitting layer 24 and the second light emitting layer 28) and the CF layer 52 are combined, the microcavity effect or the CF layer 52 or other methods are used. Since the emission color of the sub-pixel 71 is changed, it is not necessary to coat the light-emitting layer for each sub-pixel 71.

Therefore, in the present embodiment, as shown in FIG. 5, a hole injection layer 22, a hole transport layer 23, a first light emitting layer 24, an electron transport layer 25, a carrier generation layer 26, a hole transport layer 27, The second light emitting layer 28, the electron transport layer 29, the electron injection layer 30, and the second electrode 31 are uniform over the entire surface of the display region R1 in the support substrate 10 so as to cover the first electrode 21 and the edge cover 15. Is formed.

In FIG. 5, when the hole transport layer, the light emitting layer, and the electron transport layer are one unit, the unit on the first light emitting layer 24 side and the unit on the second light emitting layer 28 side are the carrier generation layer 26. However, the present embodiment is not limited to this example.

For example, units having the third light emitting layer may be stacked in the same manner, or four or more units may be stacked.

In addition, it may have a stacked structure in which the second light emitting layer and the third light emitting layer are directly stacked.

Furthermore, although not shown, a carrier blocking layer for blocking the flow of carriers such as holes and electrons may be inserted as necessary. For example, by adding a hole blocking layer as a carrier blocking layer between the light emitting layer and the electron transporting layer, it is possible to prevent holes from escaping to the electron transporting layer and to improve the light emission efficiency. Similarly, by adding an electron blocking layer as a carrier blocking layer between the light emitting layer and the hole transport layer, it is possible to prevent electrons from being released into the hole transport layer.

Also, an electron injection layer can be inserted between the electron transport layer and the carrier generation layer.

As an example of the configuration of the organic EL element 20, for example, a layer configuration as shown in the following (1) to (8) and a combination of these layers can be adopted.
(1) First electrode / hole injection layer / hole transport layer / light emitting layer (first light emitting layer) / electron transport layer / carrier generation layer / hole transport layer / light emitting layer (second light emitting layer) / electron transport Layer / electron injection layer / second electrode (2) first electrode / hole injection layer / hole transport layer / light emitting layer (first light emitting layer) / electron transport layer / electron injection layer / carrier generation layer / hole transport Layer / light emitting layer (second light emitting layer) / electron transport layer / electron injection layer / second electrode (3) first electrode / hole injection layer / hole transport layer / light emitting layer (first light emitting layer) / hole Blocking layer / electron transport layer / carrier generation layer / hole transport layer / light emitting layer (second light emitting layer) / hole blocking layer / electron transport layer / electron injection layer / second electrode (4) first electrode / hole Injection layer / hole transport layer / electron blocking layer / light emitting layer (first light emitting layer) / hole blocking layer / electron transport layer / electron injection layer / carrier generation layer / hole Sending layer / electron blocking layer / light emitting layer (second light emitting layer) / hole blocking layer / electron transport layer / electron injection layer / second electrode (5) first electrode / hole injection layer / hole transport layer / light emission Layer (first light-emitting layer) / electron transport layer / carrier generation layer / hole transport layer / light-emitting layer (second light-emitting layer) / electron transport layer / carrier generation layer / hole transport layer / light-emitting layer (third light-emitting layer) ) / Electron transport layer / electron injection layer / second electrode (6) first electrode / hole injection layer / hole transport layer / electron blocking layer / light emitting layer (first light emitting layer) / hole blocking layer / electron transport Layer / electron injection layer / carrier generation layer / hole transport layer / electron blocking layer / light emitting layer (second light emitting layer) / hole blocking layer / electron transport layer / electron injection layer / carrier generation layer / hole transport layer / Electron blocking layer / light emitting layer (third light emitting layer) / hole blocking layer / electron transport layer / electron Incoming layer / second electrode (7) first electrode / hole injection layer / hole transport layer / light emitting layer (first light emitting layer) / electron transport layer / carrier generation layer / hole transport layer / light emitting layer (second Light emitting layer) / light emitting layer (third light emitting layer) / electron transport layer / electron injection layer / second electrode (8) first electrode / hole injection layer / hole transport layer / electron blocking layer / light emitting layer (first Light emitting layer) / hole blocking layer / electron transport layer / electron injection layer / carrier generation layer / hole transport layer / electron blocking layer / light emitting layer (second light emitting layer) / light emitting layer (third light emitting layer) / hole Blocking layer / electron transport layer / electron injection layer / second electrode In the present embodiment, the carrier transport layer (hole transport layer, electron transport layer) and the W light-emitting layer (first layer) are interposed through the carrier generation layer. The light emitting layer 24 and the second light emitting layer 28) are provided. As the light emitting layer for W light emission, the first light emitting layer 24 and the second light emitting layer 28) are provided. The case of providing at least two light emitting layers of the light-emitting layer 28 has been described as an example.

However, the organic layers other than the light emitting layer are not essential layers as the organic EL layer 43, and at least one light emitting layer may be provided. What is necessary is just to form the structure of the organic electroluminescent layer 43 suitably according to the characteristic of the organic electroluminescent element 20 requested | required.

Therefore, the organic EL element 20 may have, for example, the layer configuration shown in (9).
(9) First electrode / hole injection layer / hole transport layer / light emitting layer (first light emitting layer) / electron transport layer / electron injection layer / second electrode Further, one layer has a plurality of functions. For example, the hole injection layer and the hole transport layer may be formed as independent layers as described above, or may be provided integrally with each other. That is, as the hole injection layer and the hole transport layer, a hole injection layer / hole transport layer in which the hole injection layer and the hole transport layer are integrated may be provided.

Similarly, the electron transport layer and the electron injection layer may be formed as layers independent from each other as described above, or may be provided integrally as an electron transport layer / electron injection layer.

Note that the stacking order is such that the first electrode 21 is an anode and the second electrode 31 is a cathode. When the first electrode 21 is a cathode and the second electrode 31 is an anode, the stacking order of the organic EL layers 43 is reversed.

The bottom emission organic EL element 20 is formed by using the first electrode 21 as a translucent electrode and the second electrode 31 as a reflective electrode.

On the other hand, the top emission type organic EL element 20 is formed by using the first electrode 21 as a reflective electrode and the second electrode 31 as a translucent electrode.

Note that the configuration of the organic EL element 20 is not limited to the above-described exemplary layer configuration, and a desired layer configuration can be adopted according to the required characteristics of the organic EL element 20.

<Image display method>
FIG. 6 is a schematic diagram for explaining an image display method of the organic EL display device 100 according to the present embodiment. In FIG. 6, the configuration of the main part on the optical path of the organic EL element 20 is shown in a simplified manner.

The organic EL element 20 according to the present embodiment has a microcavity structure.

The microcavity effect can be obtained, for example, by optimally designing the reflectance and film thickness of the anode and cathode, the film thickness of the organic layer, and the like.

The organic EL element 20 according to the present embodiment is a top emission type organic EL element. As shown in FIG. 6, the second electrode 31 on the side of taking out light emission as a cathode is a semitransparent electrode (semi-transmissive reflective electrode). The first electrode 21 on the side that is an anode and does not extract light emission has the reflective electrode layer 111 and functions as a reflective electrode.

For this reason, the light emitted from the light emitting layer (the first light emitting layer 24 and the second light emitting layer 28 in the example shown in FIG. 5) in the organic EL layer 43 provided between the first electrode 21 and the second electrode 31. Repeats reflection between the reflective electrode layer 111 and the second electrode 31 in the first electrode 21.

At this time, as shown in FIG. 6, by changing the

optical path lengths

73R, 73G, and 73B of the organic EL element 20 in each of the sub-pixels 71R, 71G, and 71B for each emission color, It reciprocates between the reflective layer of the 1 electrode 21 and the 2nd electrode 31, and the intensity | strength of the light of a specific wavelength is amplified.

In the present embodiment, the transparent electrode layer 121 is provided on the reflective electrode layer 111, and the thickness of the transparent electrode layer 121 is changed for each of the sub-pixels 71R, 71G, and 71B, so that each of the sub-pixels 71R, 71G, and 71B. The

optical path lengths

73R, 73G, and 73B of the organic EL element 20 are changed.

Specifically, in the present embodiment, as shown in FIGS. 5 and 6, the first electrode 21 is formed of only the reflective electrode layer 111 in the sub-pixel 71B, and the sub-pixels 71R and 71G are formed of the reflective electrode layer. 111 and the transparent electrode layer 121, and the transparent electrode layer 121 on the reflective electrode layer 111 in the sub-pixels 71R and 71G is composed of one layer or two layers, so that the sub-pixels 71R, 71G, and 71B are transparent. The film thickness of the electrode layer 121 is changed.

Thus, by changing the film thickness of the transparent electrode layer 121 in each of the sub-pixels 71R, 71G, and 71B, the microcavity effect can be changed and the emission color can be adjusted.

The

optical path lengths

73R, 73G, and 73B of the organic EL element 20 in each of the sub-pixels 71R, 71G, and 71B, that is, the optical distance of the optical path in the microcavity structure in each of the sub-pixels 71R, 71G, and 71B It is set to have a certain relationship with the wavelength.

That is, as described above, by adjusting the distance between the reflective electrode layer 111 of the first electrode 21 and the second electrode 31 in each of the sub-pixels 71R, 71G, and 71B, the intensity of light having a wavelength that matches the optical path length. Is strengthened by resonance, and only the light having the same wavelength is emitted from the second electrode 31 side. On the other hand, the intensity of the light having a wavelength other than the optical path length is reduced.

Therefore, the

optical path lengths

73R, 73G, and 73B are set to optical lengths corresponding to the color of the emitted light from the second electrode 31.

As shown in the present embodiment, for example, when the display colors in the sub-pixel 71 are R, G, and B, the

optical path lengths

73R, 73G, and 73B are emission spectrum peaks of these colors of R, G, and B, respectively. The film of the transparent electrode layer 121 in each of the sub-pixels 71R, 71G, and 71B so that the

optical path lengths

73R, 73G, and 73B become shorter in order of the optical path length 73R> the optical path length 73G> the optical path length 73B so as to match the wavelength. Thickness is set.

However, since there are a plurality of optical path lengths suitable for the resonance of each light, the optical path length 73R> the optical path length 73G> the optical path length 73B may not necessarily be shortened in this order, and other relationships may be provided.

That is, the transparent electrode layer 121 overlapping the R light organic EL layer 43 is set to a thickness suitable for the R light resonance, and the transparent electrode layer 121 overlapping the G light organic EL layer 43 is suitable for the G light resonance. The transparent electrode layer 121 is set to a thickness suitable for the resonance of the B light. Thereby, light with high color purity can be emitted, and the color reproducibility of the organic EL display device 100 can be improved.

<Method for Manufacturing Organic EL Display Device 100>
Next, a method for manufacturing the organic EL display device 100 according to the present embodiment will be described.

First, the outline of the material of each layer and the lamination method in the organic EL element 20 will be described.

<Outline of Material and Laminating Method of Each Layer in Organic EL Element 20>
The first electrode 21 is formed by patterning corresponding to the individual sub-pixels 71R, 71G, and 71B by photolithography and etching after an electrode material is formed by sputtering or the like.

As the first electrode 21, various conductive materials can be used. As described above, in the case of the bottom emission type organic EL element 20 that emits light to the insulating substrate 11 side, it needs to be translucent. is there.

On the other hand, in the case of the top emission type organic EL element 20 that emits light from the side opposite to the insulating substrate 11, the second electrode 31 needs to be translucent.

When the organic EL element 20 is a top emission type, it is desirable to use an opaque electrode for the reflective electrode layer 111 in the first electrode 21. As the reflective electrode material used for the reflective electrode layer 111, for example, Ag (silver), an Ag alloy, Al (aluminum), an Al alloy, and a laminated body (laminated film) including layers made of these electrode materials are used. it can.

In addition, as a transparent electrode material used for the transparent electrode layer 121, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), gallium-doped zinc oxide (GZO), or the like is used. Can do.

On the other hand, it is desirable to use a translucent electrode for the second electrode 31. As the translucent electrode, for example, a metal translucent electrode alone or a laminate of a metal translucent electrode layer and a transparent electrode layer can be used, and silver is preferable from the viewpoint of reflectance and transmittance.

Further, as a method of laminating the first electrode 21 and the second electrode 31, a sputtering method, a vacuum deposition method, a CVD (chemical vapor deposition) method, a plasma CVD method, a printing method, or the like can be used.

In the present embodiment, the transparent electrode layer in the first electrode 21 or the second electrode 31 (the first electrode 21 in the examples shown in FIGS. 5 and 6) is used to control the emission color emitted by the difference in optical path length. The microcavity structure is introduced into the sub-pixels 71R, 71G, and 71B by changing the thickness of the 121 to the sub-pixels 71R, 71G, and 71B.

A method for introducing a microcavity structure into the sub-pixels 71R, 71G, and 71B by changing the thickness of the transparent electrode layer 121 in this way will be described in detail later.

As a material of the organic EL layer 43, a known material can be used.

As a material of the hole injection layer, the hole transport layer, or the hole injection layer / hole transport layer, for example, anthracene, azatriphenylene, fluorenone, hydrazone, stilbene, triphenylene, benzine, styrylamine, triphenylamine, porphyrin, Linear or heterocyclic such as triazole, imidazole, oxadiazole, oxazole, polyarylalkane, phenylenediamine, arylamine, and derivatives thereof, thiophene compounds, polysilane compounds, vinylcarbazole compounds, aniline compounds Examples thereof include conjugated monomers, oligomers, and polymers.

Examples of the material for the electron transport layer, the electron injection layer, or the electron transport layer / electron injection layer include tris (8-quinolinolato) aluminum complex, oxadiazole derivative, triazole derivative, phenylquinoxaline derivative, silole derivative, and the like. .

As the material of the light emitting layer, a material having high luminous efficiency such as a low molecular fluorescent dye or a metal complex is used. For example, anthracene, naphthalene, indene, phenanthrene, pyrene, naphthacene, triphenylene, perylene, picene, fluoranthene, acephenanthrylene, pentaphen, pentacene, coronene, butadiene, coumarin, acridine, stilbene, and their derivatives, tris (8- Quinolinolato) aluminum complex, bis (benzoquinolinolato) beryllium complex, tri (dibenzoylmethyl) phenanthroline europium complex, ditoluylvinylbiphenyl, hydroxyphenyloxazole, hydroxyphenylthiazole and the like.

Note that a single material may be used for each light emitting layer, or a mixed material in which a certain material is used as a host material and another material is mixed as a guest material or a dopant may be used.

Materials for the carrier generation layer include metal oxides such as molybdenum oxide and vanadium pentoxide, or those co-deposited with aromatic hydrocarbons and carbazole derivatives, Au and Ag metal thin films, IZO and ITO, etc. Examples thereof include a transparent conductive layer (transparent electrode layer).

<Method for Manufacturing Organic EL Display Device 100>
Next, a method for manufacturing the organic EL display device 100 will be described.

However, the dimensions, materials, shapes, and the like of each component described in the present embodiment are merely one embodiment, and the scope of the present invention should not be construed as being limited thereto.

First, referring to FIG. 7, an outline of the flow of the manufacturing process of the organic EL display device 100 will be described.

FIG. 7 is a flowchart showing an example of the manufacturing process of the organic EL display device 100 in the order of processes.

Further, as described above, the stacking order described in the present embodiment is such that the first electrode 21 is an anode, the second electrode 31 is a cathode, the first electrode 21 is a cathode, and the second electrode 31 is. Is used as the anode, the material and thickness of the first electrode 21 and the second electrode 31 are reversed.

First, in step S1, a TFT 12, a signal line 14, an interlayer insulating film 13, and a contact hole 13a are formed on the display region R1 of the insulating substrate 11 as shown in FIG. 5 by a known method.

When the top emission type organic EL display device 100 is manufactured as in the present embodiment, the insulating substrate 11 is, for example, a glass substrate such as a non-alkali glass substrate having a thickness of 0.7 to 1.1 mm or a plastic substrate. Is used.

Note that the sizes of the insulating substrate 11 in the X-axis direction and the Y-axis direction may be appropriately set according to the application and the like, and are not particularly limited. In this embodiment, a non-alkali glass substrate having a thickness of 0.7 mm is used.

The interlayer insulating film 13 and the contact hole 13a are formed by applying a photosensitive resin on the insulating substrate 11 on which the TFT 12, the signal line 14, and the like are formed by a known technique, and performing patterning by a photolithography technique.

As the interlayer insulating film 13, a known photosensitive resin can be used. Examples of the photosensitive resin include acrylic resin and polyimide resin. The film thickness of the interlayer insulating film 13 is not particularly limited as long as the step due to the TFT 12 can be compensated. In the present embodiment, for example, an acrylic resin is formed with a film thickness of about 2 μm.

In this step, a pattern is formed so that signal lines 14 such as a gate line and a source line for driving the TFT 12 are led out to the terminal portion region R3. Further, in this step, for example, as shown in FIG. 3, the connection portion 60 is pattern-formed in the second electrode connection region R2.

Next, in step S2, the first electrodes 21 having different thicknesses are produced for the sub-pixels 71R, 71G, and 71B. Note that, as described above, a method of manufacturing the first electrode 21 when the organic EL display device 100 is a top emission type will be described in detail later.

Thereafter, in step S3, the end portion (pattern end portion) of the first electrode 21 is covered on the interlayer insulating film 13, and the

openings

15R, 15G are provided for the sub-pixels 71R, 71G, 71B as shown in FIG. The edge cover 15 is produced so that 15B is formed.

As with the interlayer insulating film 13, a known photosensitive resin can be used for the edge cover 15. Examples of the photosensitive resin include acrylic resin and polyimide resin.

The edge cover 15 compensates for the level difference due to the difference in the layer thickness of the first electrode 21 in the adjacent sub-pixel 71, and the first electrode 21 and the second electrode 31 are short-circuited at the end of the first electrode 21. In order to prevent this, the height from the surface of the first electrode 21 in the sub-pixel 71R where the film thickness of the first electrode 21 is the thickest is set to about 1 μm, for example.

In the present embodiment, an edge cover made of acrylic resin having a height from the surface of the interlayer insulating film 13 of about 1.2 μm so that the height from the surface of the first electrode 21 in the sub-pixel 71R is about 1 μm. 15 was formed by patterning.

Through the above steps, the support substrate 10 on which the first electrode 21 and the edge cover 15 are formed is manufactured.

Next, in step S4, the support substrate 10 that has undergone the above-described processes is subjected to oxygen plasma treatment as a vacuum baking for dehydration and surface cleaning of the first electrode 21, and then, as shown in FIG. An organic EL layer 43 is formed on the entire surface of the display region R1 of the support substrate 10 so as to cover the one electrode 21 and the edge cover 15. A method for producing the organic EL layer 43 will be specifically described later.

Thereafter, in step S5, the second electrode 31 is formed by a known method. Specifically, the second electrode 31 is formed on the entire surface of the display region R1, and is electrically connected to the connection portion 60 of the second electrode connection region R2, so that, for example, vapor deposition is performed so that these regions are exposed. A pattern is formed by a vapor deposition method using a mask for use. Note that the second electrode 31 can be manufactured using the same method as that for the organic EL layer 43.

The film thickness of the second electrode 31 is preferably 10 to 30 nm. When the film thickness of the second electrode 31 is less than 10 nm, light cannot be sufficiently reflected, and there is a possibility that the microcavity effect cannot be obtained sufficiently. On the other hand, when the film thickness of the second electrode 31 exceeds 30 nm, the light transmittance may decrease and the luminance may decrease. In the present embodiment, Ag is formed with a thickness of 20 nm as the second electrode 31.

Thereby, the organic EL element 20 including the first electrode 21, the organic EL layer 43, and the second electrode 31 was formed on the support substrate 10.

Next, in step S6, as shown in FIG. 2, the support substrate 10 on which the organic EL element 20 is formed and the sealing substrate 50 are bonded together with the sealing resin layer 41, and the organic EL element 20 is sealed. .

Moreover, the organic EL element 20 can be sealed as follows, for example.

First, as shown in FIG. 2, a sealing resin layer 41 is formed in a frame-shaped sealing region L surrounding the display region R1 and the second electrode connection region R2 in the support substrate 10 shown in FIG.

Next, as a protective film that prevents oxygen and moisture from entering the organic EL element 20 from the outside so as to cover the second electrode 31 in the space surrounded by the support substrate 10 and the sealing resin layer 41, The filling resin layer 42 having adhesiveness containing a desiccant is filled.

For example, an epoxy resin is used for the filling resin layer 42. The film thickness of the filling resin layer 42 is, for example, 1 to 20 μm.

Thereafter, the support substrate 10 and the sealing substrate 50 are bonded together via the sealing resin layer 41.

Thereby, the organic EL element 20 is sealed by the support substrate 10, the sealing substrate 50, the sealing resin layer 41, and the filling resin layer 42.

As the sealing substrate 50, for example, an insulating substrate such as a glass substrate or a plastic substrate having a plate thickness of 0.4 to 1.1 mm is used. In this embodiment, a non-alkali glass substrate having a thickness of 0.7 mm is used.

Thereafter, in step S7, as shown in FIG. 2, the circuit portion 102 is connected to the electric wiring terminal 2 in the terminal portion region R3 of the support substrate 10 through an ACF (Anisotropic Conductive Film) (not shown), for example. The connection terminal 103 is connected. In this way, the organic EL display device 100 is manufactured.

Note that the sizes of the sealing substrate 50 in the X-axis direction and the Y-axis direction may be appropriately adjusted according to the size of the target organic EL display device 100, and have substantially the same size as the insulating substrate 11 in the support substrate 10. After using the insulating substrate and sealing the organic EL element 20, it may be divided according to the size of the target organic EL display device 100.

<Flow of manufacturing process of organic EL layer 43>
Next, taking the organic EL display device 100 having the configuration shown in FIG. 5 as an example, an outline of the flow of the manufacturing process of the organic EL layer 43 in step S4 will be described.

FIG. 8 is a flowchart showing an example of a manufacturing process of the organic EL layer 43 in the order of processes.

However, the stacking order shown in FIG. 8 is such that the first electrode 21 is an anode, the second electrode 31 is a cathode, the first electrode 21 is a cathode, and the second electrode 31 is an anode. The stacking order of the organic EL layer 43 is reversed.

In step S4 shown in FIG. 7, as shown in FIG. 8, first, the hole injection layer 22 is applied to the support substrate 10 that has been subjected to oxygen plasma treatment as a vacuum baking for dehydration and surface cleaning of the first electrode 21. Is formed by vapor deposition on the entire surface of the display region R1 of the support substrate 10 so as to cover the first electrode 21 and the edge cover 15 (step S11).

For example, vacuum deposition is used for the pattern formation. In the vacuum vapor deposition method, the vapor deposition particles (film forming material) from the vapor deposition source are made so that the vapor deposition surface of the support substrate 10 to which the mask (open mask) having the entire display region R1 opened is closely fixed is opposed to the vapor deposition source. Then, vapor deposition is performed on the deposition surface through the opening of the mask. Thereby, the vapor deposition particles scattered from the vapor deposition source are uniformly vapor deposited on the entire surface of the display region R1 through the opening of the open mask.

In addition, the vapor deposition may be performed by, for example, attaching an open mask having the entire display region R1 opened to the support substrate 10 after alignment adjustment, and rotating the support substrate 10 and the open mask together. The vapor deposition particles scattered from the vapor deposition source may be vapor-deposited on the display region R1 through the opening of the open mask, and the vapor deposition source is scanned with the support substrate 10 and the open mask fixedly adhered using the open mask. Scan deposition such as vapor deposition may be performed.

Here, the vapor deposition on the entire surface of the display region R1 means that the vapor deposition is performed continuously between adjacent sub-pixels of different colors.

For the above vapor deposition, a vacuum vapor deposition apparatus similar to the conventional one can be used. Therefore, the description and illustration of the vacuum vapor deposition apparatus and the vapor deposition method are omitted here.

As described above, when a deposited film is formed using a vacuum deposition apparatus, the vacuum deposition apparatus is set to a vacuum reach of 1.0 × 10 ⁻⁴ Pa or more by a vacuum pump. desirable. In other words, it is desirable that the pressure in the vacuum chamber is set to 1.0 × 10 ⁻⁴ Pa or less.

The average free path of the vapor-deposited particles can provide a necessary and sufficient value when the degree of vacuum is higher than 1.0 × 10 ⁻³ Pa. On the other hand, when the degree of vacuum is lower than 1.0 × 10 ⁻³ Pa, the mean free path is shortened, so that the vapor deposition particles are scattered and the arrival efficiency to the support substrate 10 which is the film formation substrate is lowered. Or vapor deposition particles adhere to an unnecessary area. For this reason, it is desirable that the vacuum chamber is set to the above-mentioned vacuum reachability.

Next, in step S12, using an open mask, the hole transport layer 23 is coated with the hole injection layer 22 in the same pattern as the hole injection layer 22 so as to cover the hole injection layer 22. A pattern is formed (deposited) on the entire surface of the display region R1.

Thereafter, using an open mask, the hole injection layer 22 and the hole transport layer 23 are covered with the same pattern as the hole injection layer 22 and the hole transport layer 23 so as to cover the hole transport layer 23. The first light emitting layer 24 (Step S13), the electron transport layer 25 (Step S14), the carrier generation layer 26 (Step S15), and the hole transport layer 27 (Step S16) are formed on the entire surface of the display region R1 in each step. The second light emitting layer 28 (step S17), the electron transport layer 29 (step S18), and the electron injection layer 30 (step S19) are uniformly patterned (evaporated) in this order.

The film thickness of these organic EL layers 43 is set, for example, in the same manner as in the past.

The hole injection layer 22 and the hole transport layer 23 may be formed as independent layers as described above, or may be integrated as described above. Each film thickness is, for example, 1 to 100 nm. The total film thickness of the hole injection layer 22 and the hole transport layer 23 is, for example, 2 to 200 nm.

Further, the electron transport layer 29 and the electron injection layer 30 may be formed as independent layers as described above, or may be integrated as described above.

The film thickness of each of the electron transport layer 25, the electron transport layer 29, and the electron injection layer 30 is, for example, 1 to 100 nm. The total film thickness of the electron transport layer 29 and the electron injection layer 30 is, for example, 20 to 200 nm.

The film thickness of each of the first light emitting layer 24 and the second light emitting layer 28 is, for example, 10 to 100 nm.

The film thickness of the carrier generation layer 26 is, for example, 1 to 30 nm.

In this embodiment, copper phthalocyanine having a thickness of 2 nm was formed as the hole injection layer 22. As the hole transport layer 23, NPB (4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl) having a thickness of 30 nm was formed.

Further, as the electron transport layer 25 and the electron transport layer 29, oxadiazole derivatives each having a film thickness of 40 nm were formed. Further, as the electron injection layer 30, lithium fluoride having a thickness of 1 nm was formed.

The first light-emitting layer 24 and the second light-emitting layer 28 are films in which iridium complexes are used as guest materials and CBP (4,4′-N, N′-dicarbazole-biphenyl) is used as a host material. The film was formed with a thickness of 30 nm. In addition, as the carrier generation layer 26, a film obtained by co-evaporating molybdenum oxide and NPB was formed to a thickness of 10 nm.

In addition, when laminating | stacking the unit which has a 3rd light emitting layer, as shown with a dashed-two dotted line between step S18 and step S19, for example, a carrier generation layer (step S21) and a hole transport layer (step S22) The third light emitting layer (step S23) and the electron transport layer (step S24) are uniformly patterned (evaporated) in this order.

In this case, the material and film thickness of the carrier generation layer, the hole transport layer, the third light emitting layer, and the electron transport layer may be set in the same manner as the unit having the second light emitting layer 28, for example.

In such an organic EL display device 100, when the TFT 12 is turned on by a signal input from the signal line 14, holes are injected from the first electrode 21 to the organic EL layer 43. On the other hand, when electrons are injected from the second electrode 31 into the organic EL layer 43, the holes and electrons recombine in each light emitting layer, and the recombined holes and electrons deactivate the energy. Is emitted.

In the present embodiment, the first light-emitting layer 24 and the second light-emitting layer 28 are light-emitting layers having different emission colors, and the mixture of light emitted from the first light-emitting layer 24 and the second light-emitting layer 28 is a microcavity effect. As a result, the organic EL element 20 obtains the light.

<Method for Manufacturing First Electrode 21>
Next, a manufacturing method of the first electrode 21 in the top emission type organic EL display device 100 (that is, a manufacturing method of an electrode having a different optical path length for each subpixel 71) will be described.

FIGS. 1A to 1I are cross-sectional views showing an example of a method for manufacturing the first electrode 21 in the top emission type organic EL display device 100 shown in step S2 in order of steps.

First, as shown in FIG. 1A, amorphous ITO (amorphous) ITO (hereinafter referred to as “transparent electrode layer”) is formed on the support substrate 10 in which the interlayer insulating film 13 and the contact hole 13a shown in FIG. , "A-ITO") layer 110, reflective electrode layer 111 made of a reflective electrode material such as a metal material, and a-ITO layer 112 (first transparent electrode layer) which is a transparent electrode layer in this order. The film is formed by a method or the like.

Next, resist

patterns

201R, 201G, and 201B are formed on the a-ITO layer 112 by photolithography for each of the sub-pixels 71R, 71G, and 71B. Thereafter, using the resist

patterns

201R, 201G, and 201B as masks, the a-ITO layer 110, the reflective electrode layer 111, and the a-ITO layer 112 are etched as shown in FIG. 201R / 201G / 201B is stripped and washed with a resist stripper.

As a result, as shown in FIG. 1B, the a-ITO layer 110, the reflective electrode layer 111, and the a-ITO layer 112 are patterned so as to be separated into sub-pixels 71R, 71G, and 71B of the respective colors. . That is, the a-ITO layer 110, the reflective electrode layer 111, and the a-ITO layer 112, which are patterned for the sub-pixels 71R, 71G, and 71B of each color, are formed.

The reflective electrode material used for the reflective electrode layer 111 is preferably a reflective electrode material that does not undergo an electrolytic corrosion reaction with a-ITO. For example, any one selected from the group consisting of Ag, an Ag alloy, and an Al alloy is used. be able to.

The thickness of the reflective electrode layer 111 is set to 50 to 200 nm, for example. In this embodiment mode, a silver alloy with an electrode thickness of 100 nm is formed as the reflective electrode layer 111.

The film thickness of the a-ITO layer 110 is set to 200 nm or less (0 to 200 nm), for example. The film thickness of the a-ITO layer 112 is set to 5 to 50 nm, for example. In this embodiment, an a-ITO layer 110 with an electrode thickness of 100 nm and an a-ITO layer 112 with an electrode thickness of 20 nm are formed.

In the above etching, wet etching using, for example, a mixed solution of phosphoric acid, nitric acid, and acetic acid or ferric chloride is used as the etching solution. In addition, for example, monoisopropanolamine is used as the resist stripping solution.

Thereafter, the support substrate 10 is heat-treated (annealed) to crystallize the a-ITO layers 110 and 112 as shown in FIG.

Note that the treatment temperature and treatment time in the heat treatment may be set as appropriate so that the a-ITO layers 110 and 112 can be crystallized, and are not particularly limited.

In this embodiment, heat treatment was performed at 200 ° C. for 1 hour. As a result, a-ITO was converted to crystalline ITO (hereinafter referred to as “p-ITO”). As a result, the a-ITO layers 110 and 112 in the sub-pixels 71R, 71G, and 71B were converted into p-

ITO layers

113 and 114 as shown in FIG.

Note that in the conversion from a-ITO to p-ITO, there is no decrease in film thickness, and the film thickness at the time of film formation of a-ITO is maintained.

Next, as shown in FIG. 1 (d), the p-ITO layer 113, the reflective electrode layer 111, and the p-ITO layer 114 (first transparent electrode layer) are covered on the support substrate 10. Then, an a-ITO layer 115 (second transparent electrode layer) which is a transparent electrode layer is formed by sputtering, for example.

The film thickness of the a-ITO layer 115 is set to 40 to 120 nm, for example. In this embodiment, the a-ITO layer 115 having an electrode thickness of 80 nm is formed.

Next, as shown in FIG. 1D, on the a-ITO layer 115 in the sub-pixel 71R, the p-ITO layer 113, the reflective electrode layer 111, and the patterned electrode layer 113 in a plan view by photolithography, and A resist pattern 202R is formed so as to cover the p-ITO layer 114.

At this time, the resist pattern 202R was formed wider than the pattern of the p-ITO layer 113 in the sub-pixel 71R so as to cover the pattern end of the p-ITO layer 113 below the reflective electrode layer 111 in plan view.

In other words, the resist pattern 202R overlaps with the reflective electrode layer 111 and the p-ITO layer 113 in plan view, and is larger than the reflective electrode layer 111 and the p-ITO layer 113 in plan view.

The protruding amount of the resist pattern 202R in plan view from the pattern end of the p-ITO layer 113 was set to 2 μm.

Thereafter, using the resist pattern 202R as a mask, the a-ITO layer 115 not masked by the resist pattern 202R is wet-etched as shown in FIG. Strip and clean with a resist stripper.

For example, oxalic acid is used as the etching solution. Thereby, the a-ITO layer 115 can be selectively etched. As the resist stripping solution, a resist stripping solution similar to the resist stripping solution used in the etching shown in FIG.

At this time, the p-

ITO layers

113 and 114 and the reflective electrode layer 111 are not etched by the etching solution (oxalic acid) or the etching rate is extremely low. Therefore, the p-

ITO layers

113 and 114 and the reflective electrode layer 111 remain without being removed by the etching.

Thereby, as shown in FIG. 1E, only the a-ITO layer 115 other than the a-ITO layer 115 of the sub-pixel 71R masked by the resist pattern 202R is removed.

Thereafter, the support substrate 10 is heat-treated to crystallize the a-ITO layer 115 as shown in FIG.

Note that the treatment temperature and treatment time in the heat treatment may be set as appropriate so that the a-ITO layer 115 can be crystallized, and are not particularly limited.

In the present embodiment, the heat treatment was performed at 200 ° C. for 1 hour as in the process shown in FIG. Thereby, a-ITO was converted into p-ITO. As a result, the a-ITO layer 115 in the sub-pixel 71R was converted to the p-ITO layer 116 as shown in FIG.

Next, as shown in FIG. 1G, a transparent electrode layer is formed on the support substrate 10 so as to cover the transparent electrode layers and the reflective electrode layers 111 in the sub-pixels 71R, 71G, and 71B. The ITO layer 117 is deposited, for example, by sputtering.

The film thickness of the a-ITO layer 117 is set to 20 to 60 nm, for example. In this embodiment, as described later, since the a-ITO layer 117 in the sub-pixel 71R is removed by etching in the step shown in FIG. 1H, the film thickness of the a-ITO layer 117 is p- The a-ITO layer 117 is formed so as to be smaller than the film thickness of the ITO layer 116 (the optical path length 73R in the sub-pixel 71R). Therefore, the thickness of the a-ITO layer 117 is set to 40 nm, which is smaller than the thickness of the p-ITO layer 116.

Subsequently, as shown in FIG. 1G, the p-ITO layer 113, the reflective electrode layer 111, the patterned p-ITO layer 113, and the reflective electrode layer 111 in a plan view by photolithography on the a-ITO layer 117 in the sub-pixel 71G. A resist pattern 202G is formed so as to cover the a-ITO layer 117.

At this time, the resist pattern 202G was formed wider than the pattern of the p-ITO layer 113 in the sub-pixel 71G so as to cover the pattern end of the p-ITO layer 113 below the reflective electrode layer 111 in plan view.

That is, the resist pattern 202G also overlaps with the reflective electrode layer 111 and the p-ITO layer 113 in plan view, and is larger than the reflective electrode layer 111 and the p-ITO layer 113 in plan view.

Note that the amount of protrusion of the resist pattern 202G in plan view from the pattern end of the p-ITO layer 113 was set to 2 μm, like the resist pattern 202R.

Thereafter, using the resist pattern 202G as a mask, an a-ITO layer 117 not masked with the resist pattern 202G is wet-etched as shown in FIG. Strip and clean with a resist stripper.

Note that as the etching solution and the stripping solution, the same etching solution and stripping solution as the etching solution and stripping solution used in the etching shown in FIG. Thereby, the a-ITO layer 117 can be selectively etched.

At this time, the p-

ITO layers

113, 114, and 116 and the reflective electrode layer 111 are not etched by the etching solution (oxalic acid), or the etching rate is extremely low. For this reason, the p-

ITO layers

113, 114 and 116 and the reflective electrode layer 111 remain without being removed by the etching.

Thereby, as shown in FIG. 1H, only the a-ITO layer 117 other than the a-ITO layer 117 of the sub-pixel 71G, which has been masked by the resist pattern 202G, is removed.

Thereafter, the support substrate 10 is heat-treated to crystallize the a-ITO layer 117 as shown in FIG.

Note that the treatment temperature and treatment time in the heat treatment may be set as appropriate so that the a-ITO layer 117 can be crystallized, and are not particularly limited.

Here, similarly to the process shown in FIG. 1C, heat treatment was performed at 200 ° C. for 1 hour. As a result, the a-ITO layer 117 in the sub-pixel 71G was converted to the p-ITO layer 118 as shown in FIG.

Thereby, in the sub-pixel 71R, the reflective electrode layer 111 includes a p-ITO layer 113 which is a transparent electrode layer below the reflective electrode layer 111 and a p-ITO layer which is a transparent electrode layer above the reflective electrode layer 111. A first electrode 21 surrounded by 114 and 116 is formed.

Note that the p-

ITO layers

114 and 116, which are the transparent electrode layers above the reflective electrode layer 111, function as the transparent electrode layer 121 that forms the microcavity.

For this reason, in the sub-pixel 71R, the film thicknesses of the p-

ITO layers

113 and 116 are set so that the total film thickness of the p-

ITO layers

113 and 116 becomes the optical path length 73R of the sub-pixel 71R.

In the sub-pixel 71G, the reflective electrode layer 111 includes a p-ITO layer 113 which is a transparent electrode layer below the reflective electrode layer 111 and a p-ITO layer 114 which is a transparent electrode layer above the reflective electrode layer 111. And the first electrode 21 surrounded by the p-ITO layer 118 having a thickness smaller than that of the p-ITO layer 116 is formed.

In the subpixel 71G, the p-

ITO layers

114 and 118, which are the transparent electrode layers above the reflective electrode layer 111, function as the transparent electrode layer 121 that forms the microcavity.

Therefore, in the sub-pixel 71G, the film thicknesses of the p-

ITO layers

114 and 118 are set so that the total film thickness of the p-

ITO layers

114 and 118 becomes the optical path length 73G of the sub-pixel 71G.

In the sub-pixel 71B, the reflective electrode layer 111 includes a p-ITO layer 113 that is a transparent electrode layer below the reflective electrode layer 111, and a p-ITO layer 114 that is a transparent electrode layer above the reflective electrode layer 111. The first electrode 21 sandwiched between and is formed.

In the subpixel 71B, the p-ITO layer 114, which is the transparent electrode layer on the reflective electrode layer 111, functions as the transparent electrode layer 121 that forms the microcavity.

Therefore, in the sub-pixel 71B, the film thickness of the p-ITO layer 114 is set so that the film thickness of the p-ITO layer 114 becomes the optical path length 73G of the sub-pixel 71G.

However, the present embodiment is not limited to this, and each of the sub-pixels 71R, 71G, 71B has a transparent electrode layer having a composition different from that of the ITO layer, such as a p-ITO layer (not shown) or an IZO layer. Furthermore, you may have the structure laminated | stacked.

As described above, according to the present embodiment, as described above, the a-ITO layer is formed, the patterning step of patterning the a-ITO layer by etching using photolithography, and the patterned a-ITO By repeating the crystallization step of converting the layer into a p-ITO layer, an arbitrary number of p-ITO layers can be stacked on an arbitrary sub-pixel.

Through the above processing, as shown in FIG. 1I, the film thickness of the transparent electrode layer 121 can be changed for each of the sub-pixels 71R, 71G, and 71B of different colors.

In the present embodiment, after forming the first electrode 21 in this way, the edge cover 15 is produced as shown in step S3.

FIG. 9A is a cross-sectional view schematically showing a schematic configuration of the first electrode 21 when the edge cover 15 is produced on the first electrode 21 in step S3, and FIG. 4 is a plan view schematically showing a schematic configuration of the first electrode 21 when the edge cover 15 is produced on the first electrode 21 in step S3. FIG.

In the present embodiment, as shown in FIG. 1D, the resist pattern 202R is sub-pixel covered so as to cover the pattern end of the p-ITO layer 113 under the reflective electrode layer 111 in plan view. It is formed wider than the pattern of the p-ITO layer 113 in 71R.

Therefore, in this embodiment, the a-ITO layer 115 around the p-ITO layer 113 covered with the resist pattern 202R is not etched away by the etching in the step shown in FIG. As shown in FIGS. 9A and 9B, the patterned reflective electrode layer 111 and the p-ITO layer 113 remain so as to cover them.

In this embodiment, as shown in FIG. 1G, the resist pattern 202G covers the pattern end of the p-ITO layer 113 below the reflective electrode layer 111 in plan view. It is formed wider than the pattern of each p-ITO layer 113 in the sub-pixel 71G.

Therefore, in this embodiment, the a-ITO layer 117 around the p-ITO layer 113 covered with the resist pattern 202G is not etched away by the etching in the step shown in FIG. As shown in FIGS. 9A and 9B, the patterned reflective electrode layer 111 and the p-ITO layer 113 remain so as to cover them.

For this reason, in this embodiment, after the step shown in FIG. 1E or FIG. 1H, in each of the sub-pixels 71R and 71G, not only the upper layer of the reflective electrode layer 111 but also the side surfaces thereof are not exposed. .

In the steps shown in FIGS. 1A to 1I, a plurality of p-ITO layers are stacked on the reflective electrode layer 111 in the sub-pixels 71R and 71G, but the sub-pixel forming the resist pattern is changed. Thus, it goes without saying that a plurality of p-ITO layers can be stacked on the reflective electrode layer 111 in an arbitrary subpixel.

Further, when the number of p-ITO layers stacked on the reflective electrode layer 111 is increased, the p-ITO is formed on the sub-pixel 71B in the same manner as the process shown in FIG. 1D or FIG. By forming the layer, not only in the

subpixels

71R and 71G but also in the subpixel 71B, the reflective electrode layer 111 includes a p-ITO layer 113 which is a transparent electrode layer below the reflective electrode layer 111, and a reflective electrode layer Thus, the first electrode 21 surrounded by the p-

ITO layers

114 and 116, which are upper transparent electrode layers 111, can be obtained.

<Effect>
As described above, in the present embodiment, the a-ITO layer 112 (the first electrode) is formed as a transparent electrode layer made of an amorphous transparent electrode material above the reflective electrode layer 111 (for example, on the reflective electrode layer 111). After the transparent electrode layer is formed and etched together, the a-ITO layer 112 is converted into a transparent electrode layer made of a polycrystalline transparent electrode material (that is, the p-ITO layer 114). The sub-pixels 71R and 71G are formed by laminating the transparent electrode layers by utilizing the difference in etching resistance with the a-ITO layers 115 and 117 (second transparent electrode layers) which are transparent electrode layers formed on the substrate. -The total film thickness of the said transparent electrode layer is changed between 71B.

Thus, according to the present embodiment, as described above, the a-ITO layer 112 is formed above the reflective electrode layer 111, and the reflective electrode layer 111 and the a-ITO layer 112 are etched together. Thus, the p-ITO layer 114 can be stacked on the reflective electrode layer 111 without increasing the number of times of photolithography.

In addition, according to the present embodiment, the a-ITO layers 115 and 117 which are transparent electrode layers (second transparent electrode layers) having lower etching resistance than the p-ITO layer 114 (first transparent electrode layer) are formed. Before the film formation, the a-ITO layer 112 is laminated in advance on each of the

subpixels

71R, 71G, 71B, so that the second transparent electrode layer can be laminated on any subpixel 71.

Therefore, as in Patent Document 3, an ITO layer having crystallinity is separately formed and patterned in order to build up the transparent electrode layer, and the transparent electrode layer having the same film thickness is formed on two sub-pixels every time photolithography is performed. Even if the pattern is not formed, the total film thickness of the transparent electrode layer on the reflective electrode layer 111 (that is, the transparent electrode layer 121) for each of the sub-pixels 71R, 71G, and 71B having different display colors by photolithography twice. The first electrode 21 having a different thickness can be formed.

That is, according to this embodiment, as shown in FIGS. 1D and 1G, it is necessary to change the film thickness (the number of stacked layers) of the transparent electrode layer for each of the sub-pixels 71R, 71G, and 71B. As the number of times of photolithography, the film thickness of the transparent electrode layer 121 on the reflective electrode layer 111 can be arbitrarily changed for each of the sub-pixels 71R, 71G, and 71B by photolithography. Further, according to the present embodiment, the number of photolithography can be suppressed to three even when the etching of the reflective electrode layer 111 is included.

Therefore, according to the present embodiment, even if the number of times of photolithography is reduced as described above, the film thickness of the second transparent electrode layer in an arbitrary subpixel 71 is set to be equal to that of the second subpixel 71. It is possible to set the thickness independently of the transparent electrode layer.

Therefore, in this embodiment, as described above, the difference in etching selectivity between the transparent electrode layer made of an amorphous transparent electrode material and the transparent electrode layer made of a polycrystalline transparent electrode material (for example, as described above) The transparent electrode layers in each color single layer are stacked using the difference in etching selectivity between the a-ITO layer and the p-ITO layer).

According to the present embodiment, the etching resistance to the etching solution can be increased by converting the amorphous transparent electrode material into the polycrystalline transparent electrode material.

For this reason, according to the present embodiment, the

optical path lengths

73R, 73G, and 73B in the sub-pixels 71R, 71G, and 71B are arbitrarily and easily adjusted without being restricted by the optical path length as in Patent Document 3. be able to.

Therefore, according to the present embodiment, the film thickness of the first electrode 21, in other words, the optical path length of the organic EL element 20 can be arbitrarily set for each sub-pixel 71 having a different display color by a smaller number of photolithography than conventional. Can be changed.

Therefore, the cost can be reduced and the footprint can be reduced as compared with the conventional case.

In addition, as described above, in the conventional method, the photoresist stripping and baking steps increase, so that the surface of the reflective electrode layer is roughened or oxidized to reduce the reflection efficiency, or the electrode due to the rough surface of the reflective electrode. There was a risk that a leak would occur, resulting in a pixel defect.

However, according to the present embodiment, since the number of times of exposure, development, resist stripping, and the like can be reduced, there is no such fear, and the quality of the support substrate 10 that is an organic EL substrate is improved. Can do. Further, the processing tact can be shortened.

Further, when the terminal portion of the reflective electrode layer 111 or the signal line 14 is formed of Ag, if the Ag is in an exposed state (that is, an exposed state), for example, the support substrate 10 is provided to improve the wettability of the resist. When ultraviolet irradiation is performed, the exposed Ag is oxidized to silver oxide.

For this reason, when the terminal portion of the reflective electrode layer 111 or the signal line 14 is formed of Ag, it is not desirable that Ag is exposed when the ultraviolet rays are irradiated.

Further, when the reflective electrode layer 111 or the terminal portion of the signal line 14 is made of Al, Al has low solvent resistance, and there is a possibility that the solvent penetrates through the IZO layer.

For this reason, in any case, it is desirable that the reflection electrode layer 111 and the terminal portion of the signal line 14 are covered with the p-ITO layer as described above.

According to the present embodiment, the p-ITO layer formed on the lower layer or the upper layer of the reflective electrode layer 111 is also formed on the terminal portion of the signal line 14 such as the source line in the film formation process of the a-ITO layer. By forming the ITO layer, it can be used as a protective film covering the terminal portion of the signal line 14 such as a source line.

In addition, also about the other transparent electrode layer laminated | stacked on the reflective electrode layer 111, these transparent electrode layers are laminated | stacked on the terminal parts of signal lines 14, such as a source line, and the protective film which covers the terminal part of the signal lines 14 Can be used as

In addition, according to the present embodiment, the reflection electrode layer 111 and the terminal portion of the signal line 14 are covered with the p-

ITO layers

113 and 114 at an early stage in the manufacturing process. The reflective electrode layer 111 is protected from the above factors that may impair the quality of the reflective electrode layer 111, such as reducing the number of times or the area in which the terminal portions of the signal line 14 and the signal line 14 are immersed in the developer. be able to.

Further, as described above, the resist

patterns

202R and 202G are formed wider than the pattern of the p-ITO layer 113 in each of the sub-pixels 71R and 71G in plan view, and the reflective electrode layer 111 is formed as p-ITO as described above. The same effect can be obtained by sandwiching between layers or sealing with a p-ITO layer.

Note that p-ITO is not only obtained by heat-treating a-ITO, but can also be formed directly by a film forming apparatus. However, when p-ITO is formed directly, the flatness of the film is lowered due to the growth of crystal grains during the film formation, and pinholes between crystals are easily generated. When the flatness of the film is lowered, the organic EL element 20 is easily damaged due to a short circuit between the first electrode 21 and the second electrode 31. In addition, if a pinhole is generated, the etching solution or the developer may permeate there, and the underlying film may be damaged. For this reason, the p-ITO layer is preferably converted into a p-ITO layer after the a-ITO layer is formed and then patterned.

Also, as shown in FIGS. 1B to 1J, the first electrode 21 is formed in a tapered shape by using an etching solution suitable for the electrode layer material. By forming the first electrode 21 in a tapered shape, film peeling or film cracking of each layer in the first electrode 21 is difficult to occur.

In Patent Document 3, after patterning the reflective electrode layer, ITO having crystallinity is formed and patterned on the first and third subpixels. However, ITO having crystallinity is highly soluble in an etching solution used for etching the reflective electrode layer.

For this reason, when an ITO layer having crystallinity is directly formed on the reflective electrode layer and patterned by photolithography, the reflective electrode layer may not be tapered.

On the other hand, if the reflective electrode layer and the crystalline ITO layer are separately patterned in order to avoid the above problems, the number of times of photolithography increases.

However, according to the present embodiment, as described above, the a-ITO layers 110 and 112 are formed and the reflective electrode layer 111 is patterned together. Such a problem does not occur because of the conversion to 114.

<Modified example of photolithography>
In the present embodiment, as shown in FIG. 1G, the thickness of the a-ITO layer 117 is made smaller than the thickness of the p-ITO layer 116 (that is, the optical path length 73R in the sub-pixel 71R). The case where the a-ITO layer 117 in the sub-pixel 71R is removed by etching in the process shown in FIG. 1H has been described as an example.

However, the present embodiment is not limited to this. A resist pattern is formed on both the sub-pixels 71R and 71G in the step shown in FIG. 1G, and the a-ITO layer 117 in the sub-pixel 71R is not etched away in the step shown in FIG. When leaving, it is not always necessary to set the film thickness of the a-ITO layer 117 to be smaller than the film thickness of the p-ITO layer 116.

In this case, the p-ITO layer 118 having the same film thickness is formed in each of the sub-pixels 71R and 71G by crystallizing the a-ITO layer 117.

However, in this embodiment, the resist pattern 202R is formed only on the sub-pixel 71R in the step shown in FIG. 1D, so that an a-ITO other than the sub-pixel 71R is formed as shown in FIG. The layer 115 is removed, and the a-ITO layer 115 is stacked only on the sub-pixel 71R.

Therefore, according to the present embodiment, the film thickness of the a-ITO layer 112 is set so as to obtain a desired optical path length 73B, and the film thickness of the a-ITO layer 112 (in other words, from the desired optical path length 73G) The film thickness of the a-ITO layer 117 is set to a film thickness obtained by subtracting the film thickness of the p-ITO layer 114), and the film thickness of the a-ITO layer 112 and the film of the a-ITO layer 117 from the desired optical path length 73R. By setting the film thickness of the a-ITO layer 115 to the film thickness minus the thickness, the

optical path lengths

73R, 73G, and 73B of the sub-pixels 71R, 71G, and 71B can be set and changed arbitrarily and easily. .

In this embodiment, as a specific example, the electrode thickness of the a-ITO layer 112 (p-ITO layer 114) is 20 nm, the electrode thickness of the a-ITO layer 115 (p-ITO layer 116) is 80 nm, The case where the electrode thickness of the a-ITO layer 117 (p-ITO layer 118) is 40 nm has been described as an example. However, the above specific example is merely an example, and the present embodiment is not limited thereto. is not.

For example, the electrode thickness of the a-ITO layer 112 (p-ITO layer 114) can be further increased depending on the design such as the film thickness design of the organic EL layer 43.

<Modification of sealing method of organic EL element 20>
Further, in the present embodiment, as described above, the adhesive filling resin layer 42 containing a desiccant is formed on the organic EL element 20, whereby the support substrate 10 and the sealing substrate 50 are bonded together. In addition, the case where the organic EL element 20 is sealed has been described as an example.

However, the present embodiment is not limited to this. Instead of filling the space surrounded by the support substrate 10, the sealing substrate 50, and the sealing resin layer 41 with the sealing resin, a hollow structure in which an inert gas is sealed in the space may be used. In addition, it may have a structure in which a desiccant is applied or pasted in the hollow structure. However, when light is emitted from the sealing substrate 50 side, it is necessary to prevent light from being blocked by the desiccant.

In the present embodiment, an example in which the organic EL element 20, the sealing resin layer 41, the filling resin layer 42, and the sealing substrate 50 are provided in this order on the support substrate 10 is an example. And explained. However, the present embodiment is not limited to this.

For example, in order to further improve the sealing performance of the organic EL element 20, an inorganic film (not shown), a mixed organic / inorganic laminated film, or the like may be laminated on the organic EL element 20.

Furthermore, the sealing resin layer 41, the sealing substrate 50, and the filling resin layer 42 can be omitted if the sealing performance of the organic EL element 20 is sufficient only with an inorganic film or an organic / inorganic mixed laminated film.

Moreover, in this Embodiment, the case where the organic EL element 20 is sealed by bonding the support substrate 10 and the sealing substrate 50 through the sealing resin layer 41 formed in the frame shape is an example. And explained.

However, the sealing method of the organic EL element 20 is not limited to this, and for example, frit glass (powder glass) is formed in a frame shape instead of the sealing resin, and the organic EL element 20 is sealed. May be.

<Variation of pixel configuration>
Further, in the present embodiment, the case where one pixel 70 is configured by sub-pixels 71R, 71G, and 71B of three colors of R, G, and B has been described as an example. However, the present embodiment is not limited to this. One pixel 70 may be composed of sub-pixels 71 of three colors other than R, G, and B, such as cyan (C), magenta (M), and yellow (Y).

Further, for example, it may be composed of four or more sub-pixels 71 such as four-color sub-pixels 71 obtained by adding Y or the like to R, G, and B.

According to the present embodiment, as described above, the difference in etching selectivity between the lower p-ITO (first transparent electrode layer) and the upper a-ITO layer (second transparent electrode layer). For example, a transparent electrode layer having an arbitrary film thickness can be formed on an arbitrary sub-pixel 71 by stacking transparent electrode layers in each color single layer.

In the present embodiment, the number of transparent electrode layers on the reflective electrode layer 111 is not particularly limited, and can be arbitrarily set.

In any case, according to the present embodiment, as compared with the case where the same number of transparent electrode layers are stacked, the reflective electrode is formed between the sub-pixels having different display colors by a smaller number of photolithography than the conventional case. The number of transparent electrode layers on the layer and the total film thickness can be changed.

In this embodiment, as described above, the active matrix organic EL display device 100 in which the TFT 12 is formed in each sub-pixel 71 is taken as an example. However, the present embodiment is not limited to this, and as long as it is not affected by the driving method of the organic EL element 20, the manufacture of a passive matrix organic EL display device in which TFTs are not formed is also possible. The present invention can be applied.

<Modification of Method for Manufacturing Organic EL Layer 43>
Moreover, in this Embodiment, the case where the organic electroluminescent layer 43 was produced by the vacuum evaporation method was mentioned as an example, and was demonstrated. However, the manufacturing method of the organic EL layer 43 is not limited to this, and it goes without saying that a conventionally known organic film forming method such as an ink jet method or a laser transfer method can be appropriately selected and adopted.

<Modification of display device>
Further, in this embodiment, the display device using the organic EL element as the light emitting element is described as an example of the display device manufactured in this embodiment. However, this embodiment is not limited to this, and can be widely applied to display devices using light-emitting elements that can be configured as microresonators such as inorganic EL elements.

[Embodiment 2]
The following describes the present embodiment mainly based on FIGS. 10A to 10H.

In the present embodiment, differences from the first embodiment will be mainly described. Components having the same functions as those used in the first embodiment are denoted by the same reference numerals. The description is omitted.

The organic EL display device 100 according to the present embodiment is the same as that of the first embodiment except that the laminated structure of the first electrode 21 and the method for producing the first electrode 21 shown in step S2 are different from those of the first embodiment. It is. Therefore, in this embodiment, another manufacturing method and a stacked structure of the first electrode 21 shown in step S2 will be described.

<Method for Manufacturing First Electrode 21>
FIGS. 10A to 10H show an example of processes from the production of the first electrode 21 in the top emission type organic EL display device 100 shown in step S2 to the production of the edge cover shown in step S3. It is sectional drawing shown to process order.

In the present embodiment, the steps shown in FIGS. 10 (a) to (c) are the same as the steps shown in FIGS. 1 (a) to (c). Therefore, the description of the steps shown in FIGS. 10A to 10C is omitted.

In the present embodiment, after the step shown in FIG. 10C, the p-ITO layer 113, the reflective electrode layer 111, and the p-ITO layer 113 are formed on the support substrate 10 as shown in FIG. 10D. -An IZO layer 131 (second transparent electrode layer), which is a transparent electrode layer, is formed by sputtering, for example, so as to cover the ITO layer 114 (first transparent electrode layer).

The film thickness of the IZO layer 131 is set to 20 to 60 nm, for example. In this embodiment mode, an IZO layer 131 with a thickness of 40 nm is formed.

Subsequently, as shown in FIG. 10D, the p-ITO layer 113, the reflective electrode layer 111, and the p-ITO layer 114 are formed on the IZO layer 131 in the sub-pixel 71R by photolithography in plan view. A resist pattern 202R is formed so as to cover the surface.

Thereafter, using the resist pattern 202R as a mask, the IZO layer 131 not masked by the resist pattern 202R is wet-etched using an etching solution, and then the resist pattern 202R is peeled and washed with a resist stripping solution.

Note that as the etching solution and the stripping solution, the same etching solution and stripping solution as the etching solution and stripping solution used in the etching step shown in FIG. For example, oxalic acid is used as the etching solution. Thereby, the IZO layer 131 can be selectively etched.

At this time, the p-

ITO layers

Thereby, as shown in FIG. 10E, only the IZO layer 131 other than the IZO layer 131 of the sub-pixel 71R masked by the resist pattern 202R is removed.

Next, as shown in FIG. 10 (f), an IZO that is a transparent electrode layer is formed on the support substrate 10 so as to cover the transparent electrode layer 111 and the reflective electrode layer 111 in each of the sub-pixels 71R, 71G, and 71B. The layer 132 is formed by sputtering, for example.

The film thickness of the IZO layer 132 is set to 20 to 60 nm, for example. In this embodiment, the thickness of the IZO layer 132 is 40 nm.

10F, the patterned transparent electrode layer 111 and the reflective electrode layer 111 are covered on the IZO layer 132 in the

subpixels

71R and 71G by photolithography in plan view. In this manner, resist

patterns

203R and 203G are formed.

At this time, the resist pattern 203G is formed wider than the pattern of the p-ITO layer 113 in the sub-pixels 71R and 71G so as to cover the pattern end of the p-ITO layer 113 below the reflective electrode layer 111 in plan view. did.

Note that the amount of protrusion of the resist pattern 203G in plan view from the pattern end of the p-ITO layer 113 was set to 2 μm, like the resist pattern 202R.

Further, the resist pattern 203R was formed wider than the pattern of the IZO layer 131 in the sub-pixels 71R and 71G so as to cover the pattern end of the IZO layer 131 in plan view.

Note that the amount of protrusion of the resist pattern 203G in plan view from the pattern end of the IZO layer 131 was set to 2 μm.

After that, using the resist

patterns

203R and 203G as a mask, the IZO layer 132 not masked with the resist

patterns

203R and 203G is wet-etched as shown in FIG. -203G is stripped and washed with a resist stripping solution.

Note that as the etching solution and the stripping solution, the same etching solution and stripping solution as the etching solution and stripping solution used in the etching shown in FIG. Thereby, the IZO layer 132 can be selectively etched.

At this time, as described above, the p-

ITO layers

113 and 114 and the reflective electrode layer 111 are not etched with the etching solution (oxalic acid) or the etching rate is extremely slow. Therefore, the p-

ITO layers

Thereby, as shown in FIG. 10G, only the IZO layer 132 other than the IZO layer 132 of the sub-pixels 71R and 71G, which has been masked by the resist

patterns

203R and 203G, is removed.

As a result, as shown in FIG. 10G, in the sub-pixel 71R, the reflective electrode layer 111 includes the p-ITO layer 113, which is a transparent electrode layer below the reflective electrode layer 111, and the reflective electrode layer 111. The first electrode 21 surrounded by the p-ITO layer 114 and the IZO layers 131 and 132 which are upper transparent electrode layers is formed.

In the sub-pixel 71G, the reflective electrode layer 111 includes a p-ITO layer 113 which is a transparent electrode layer below the reflective electrode layer 111 and a p-ITO layer 114 which is a transparent electrode layer above the reflective electrode layer 111. Then, the first electrode 21 surrounded by the IZO layer 132 is formed.

Thereafter, as shown in FIG. 10H, the edge cover 15 is formed on the first electrode 21 in each of the sub-pixels 71R, 71G, 71B in step S3.

In the present embodiment, the p-ITO layer 114 and the IZO layers 131 and 132 that are the transparent electrode layers on the reflective electrode layer 111 function as the transparent electrode layer 121 that forms the microcavity.

Therefore, in the sub-pixel 71R, the p-ITO layer 114 and the IZO layers 131 and 132 are formed such that the total film thickness of the p-ITO layer 114 and the IZO layers 131 and 132 becomes the optical path length 73R of the sub-pixel 71R. The thickness is set.

In the sub-pixel 71G, the p-ITO layer 114 and the IZO layer 132, which are the transparent electrode layers above the reflective electrode layer 111, function as the transparent electrode layer 121 that forms the microcavity.

Therefore, in the sub-pixel 71G, the film thicknesses of the p-ITO layer 114 and the IZO layer 132 are set so that the total film thickness of the p-ITO layer 114 and the IZO layer 132 becomes the optical path length 73G of the sub-pixel 71G. Yes.

In the sub-pixel 71B, the p-ITO layer 114, which is the transparent electrode layer on the reflective electrode layer 111, functions as the transparent electrode layer 121 that forms the microcavity.

As described above, according to the present embodiment, after the a-ITO layer 112 is crystallized and converted into the p-ITO layer 114 as described above, the p-ITO layer 114 is formed on the p-ITO layer 114. By forming an IZO layer as a transparent electrode layer having lower etching resistance than that, and selectively etching and patterning the IZO layer by photolithography, the IZO layer can be stacked on an arbitrary subpixel.

This makes it possible to change the number of laminated transparent electrode layers between at least two subpixels.

Further, according to the present embodiment, an IZO layer having a lower etching resistance than the p-ITO layer 114 is formed, and the process of selectively etching and patterning the IZO layer by photolithography is repeated. The IZO layer can be stacked on the sub-pixels.

<Modification>
However, this embodiment is not limited to this, and has a configuration in which a transparent electrode layer such as a p-ITO layer or an IZO layer (not shown) is further stacked on each of the sub-pixels 71R, 71G, and 71B. It may be.

For example, in this embodiment, the IZO layer 131 is laminated as a single layer in the step shown in FIG. 10D, but at this time, a plurality of layers including the IZO layer 131 having lower etching resistance than the p-ITO layer 114 are used. The transparent electrode layer may be formed.

For example, in the step shown in FIG. 10D, an a-ITO layer may be further formed on the IZO layer 131, and then the resist pattern 202R may be formed on the sub-pixel 71R. The resist pattern 202R may be formed on the sub-pixel 71R after forming the a-ITO layer and the IZO layer in this order.

In the case where the a-ITO layer is formed as the transparent electrode layer having a lower etching resistance than the p-ITO layer 114 as described above, after the wet etching using the resist pattern 202R as a mask as in the first embodiment. Then, heat treatment may be performed to convert the a-ITO layer into a p-ITO layer.

Note that the same method can be applied to the steps shown in FIGS. 10E and 10F, as well as the step shown in FIG. 10G and FIG. 10H. Between the steps shown in (1), a layer having a lower etching resistance than that of the p-ITO layer is laminated in a single layer or a plurality of layers, and wet etching is performed in the same manner as described above, so that further transparent electrode layers can be stacked. Needless to say, there is.

<Effect>
In the present embodiment, the difference in etching selectivity between the transparent electrode layer made of a polycrystalline transparent electrode material and the transparent electrode layer formed on the transparent electrode layer made of the polycrystalline transparent electrode material, for example, as described above As described above, the transparent electrode layer is stacked by utilizing the difference in etching selectivity between the p-ITO layer and the IZO layer (and the a-ITO layer).

In the example shown in FIG. 10G, the IZO layer 132 having the same film thickness is formed in each of the sub-pixels 71R and 71G.

However, in the present embodiment, the resist pattern 202R is formed only on the sub-pixel 71R in the step shown in FIG. 10D, so that the IZO layer 131 other than the sub-pixel 71R is formed as shown in FIG. The IZO layer 131 is stacked only on the sub-pixel 71R.

Therefore, according to the present embodiment, the film thickness of the a-ITO layer 112 is set so as to obtain a desired optical path length 73B, and the film thickness of the a-ITO layer 112 (in other words, from the desired optical path length 73G) The film thickness of the IZO layer 131 is set to the film thickness obtained by subtracting the film thickness of the p-ITO layer 114, and the film thickness of the a-ITO layer 112 and the film thickness of the IZO layer 131 are subtracted from the desired optical path length 73R. By setting the film thickness of the IZO layer 132 to the desired film thickness, the

optical path lengths

73R, 73G, and 73B of the sub-pixels 71R, 71G, and 71B can be set and changed arbitrarily and easily.

Therefore, also in this embodiment, the

optical path lengths

73R, 73G, and 73B in the sub-pixels 71R, 71G, and 71B can be arbitrarily set by two photolithography without being restricted by the optical path length as in Patent Document 3. It can be easily adjusted.

For this reason, also in this embodiment, as shown in (d) and (g) of FIG. 10, the photo necessary for changing the film thickness (number of layers) of the transparent electrode layer for each of the

subpixels

71R, 71G, and 71B. As the number of times of lithography, the thickness of the first electrode 21 can be arbitrarily and easily changed for each sub-pixel 71 by performing photolithography twice.

Also in this embodiment, as described above, the number of times of photolithography can be suppressed to three even if the etching of the reflective electrode layer 111 is included. Moreover, the p-ITO layer 114 can be formed as a transparent electrode layer also on the reflective electrode layer 111 of the sub-pixel 71B having the shortest optical path length without increasing the number of times of photolithography.

Therefore, the film thickness of the first electrode 21, in other words, the optical path length of the organic EL element 20 can be arbitrarily changed for each sub-pixel 71 by a smaller number of photolithography than the conventional method.

Moreover, according to the present embodiment, as described above, without converting the transparent electrode layer made of the amorphous transparent electrode material into the transparent electrode layer made of the polycrystalline transparent electrode material, the polycrystalline transparent electrode material The difference in etching selectivity between the transparent electrode layer made of the transparent electrode layer and the transparent electrode layer formed on the transparent electrode layer made of the polycrystalline transparent electrode material, for example, the etching of the p-ITO layer and the IZO layer as described above The transparent electrode layer can be stacked using the difference in selectivity. Therefore, the processing tact can be further shortened.

Also in this embodiment, the p-ITO layer formed on the lower layer or the upper layer of the reflective electrode layer 111 is also formed on the terminal portion of the signal line 14 such as the source line in the film forming process of the a-ITO layer. By forming the ITO layer, it can be used as a protective film covering the terminal portion of the signal line 14 such as a source line.

Moreover, also about the other transparent electrode layer laminated | stacked on the reflective electrode layer 111, the protective film which covers the terminal part of the signal line 14 by laminating | stacking these transparent electrode layers on the terminal parts of signal lines 14, such as a source line. Can be used as

[Embodiment 3]
This embodiment will be described as follows mainly based on FIG. 11 and FIG.

In this embodiment, differences from

Embodiments

1 and 2 will be mainly described, and the same components as those used in

Embodiments

1 and 2 have the same functions. A number is assigned and description thereof is omitted.

FIG. 11 is a cross-sectional view showing a schematic configuration of the organic EL display panel 1 according to the present embodiment. An exploded sectional view showing a schematic configuration of a main part of the organic EL display device 100 according to the present embodiment is the same as FIG. 2, and a plan view showing a schematic configuration of the support substrate 10 in the organic EL display device 100 is a diagram. Same as 3. Moreover, the top view which shows the structure of the principal part of display area R1 in the support substrate 10 is the same as FIG. FIG. 11 corresponds to a cross-sectional view showing a schematic configuration of the organic EL display panel 1 when the organic EL display panel 1 is cut along the line AA shown in FIG.

In the first and second embodiments, as described above, the case where W light emission is obtained by stacking a plurality of light emitting layers and superimposing emission colors has been described as an example.

However, the method for forming the first electrode 21 shown in

Embodiments

1 and 2 uses a separate coating method in which vapor deposition is performed for each color of the light emitting layer, so that a plurality of light emitting layers having different light emitting colors can be formed in the same plane. The same applies to the formation.

In the full-color organic EL display device 100 using the separate coloring method, as shown in FIG. 11, for example, the organic EL element 20 including the

light emitting layers

82R, 82G, and 82B for each color of RGB includes sub-pixels 71R, 71G, and 71B is arranged on the support substrate 10. In such an organic EL display device 100, the TFT 12 is used to perform color image display by selectively causing the organic EL elements 20 to emit light with a desired luminance.

In the present embodiment, a plurality of light emitting

layers

82R, 82G, and 82B having different emission colors are formed in the same plane as described above, and a microcavity structure is formed in each of the sub-pixels 71R, 71G, and 71B having different emission colors. By introducing this, full-color image display is performed as described above.

Also in the present embodiment, the CF layer 52 can be used to adjust the spectrum of light emitted from the organic EL element 20 as shown in FIG.

The organic EL display device 100 according to the present embodiment is the same as the organic EL display device 100 shown in FIG. 5 except that the stacked structure of the organic EL layer 43 in the organic EL element 20 is different as shown in FIG. It has a configuration.

Hereinafter, the configuration of the organic EL element 20 according to the present embodiment will be described.

<Configuration of Organic EL Element 20>
In the organic EL display device 100 shown in FIG. 11, between the first electrode 21 and the second electrode 31, as the organic EL layer 43, for example, from the first electrode 21 side, for example, a hole injection layer / hole transport layer 81. The

light emitting layers

82R, 82G, and 82B and the electron transport layer / electron injection layer 83 are configured in this order.

The hole injection layer / hole transport layer and the electron transport layer / electron injection layer are as described in the first embodiment. Here, the hole injection layer / hole transport layer 81 and the electron transport layer / electron Description of the injection layer 83 is omitted.

As shown in FIG. 11, the hole injection layer / hole transport layer 81 is uniformly formed over the entire surface of the display region R <b> 1 on the support substrate 10 so as to cover the first electrode 21 and the edge cover 15. .

On the hole injection layer / hole transport layer 81,

light emitting layers

82R, 82G, and 82B are formed corresponding to the sub-pixels 71R, 71G, and 71B, respectively.

The

light emitting layers

82R, 82G, and 82B emit light by recombining holes injected from the first electrode 21 side with electrons injected from the second electrode 31 side. Also in the present embodiment, the

light emitting layers

82R, 82G, and 82B are each formed of a material having high luminous efficiency, such as a low molecular fluorescent dye or a metal complex.

The electron transport layer / electron injection layer 83 covers the light emitting layers 82R / 82G / 82B and the hole injection layer / hole transport layer 81 so as to cover the light emitting layers 82R / 82G / 82B and the hole injection layer / hole transport layer 81. On the upper surface, it is uniformly formed over the entire surface of the display region R1 in the support substrate 10.

In the present embodiment, as described above, a case where the hole injection layer / hole transport layer 81 is provided as the hole injection layer and the hole transport layer is illustrated as an example, and the electron transport layer and As an electron injection layer, the case where an electron transport layer / electron injection layer 83 is provided is shown as an example. However, this embodiment is not limited to this, and the hole injection layer and the hole transport layer may be formed as independent layers. Similarly, the electron transport layer and the electron injection layer may be formed as independent layers.

The organic layers other than the

light emitting layers

82R, 82G, and 82B are not essential layers as the organic EL layer 43, and may be appropriately formed according to the required characteristics of the organic EL element 20.

Further, like the hole injection layer / hole transport layer 81 and the electron transport layer / electron injection layer 83, one layer may have a plurality of functions.

In addition, a carrier blocking layer can be added to the organic EL layer 43 as necessary. For example, by adding a hole blocking layer as a carrier blocking layer between the light emitting

layers

82R, 82G, and 82B and the electron transport layer / electron injection layer 83, holes escape to the electron transport layer / electron injection layer 83. Can be prevented and the luminous efficiency can be improved.

Also in this embodiment, layers other than the first electrode 21 (anode), the second electrode 31 (cathode), and the

light emitting layers

82R, 82G, and 82B may be inserted as appropriate.

As the configuration of the organic EL element 20, for example, a layer configuration as shown in the following (1) to (8) can be adopted.
(1) First electrode / light emitting layer / second electrode (2) First electrode / hole transport layer / light emitting layer / electron transport layer / second electrode (3) First electrode / hole transport layer / light emitting layer / Hole blocking layer / electron transport layer / second electrode (4) first electrode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / second electrode (5) first electrode / Hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / second electrode (6) first electrode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / second electrode (7) first electrode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / second electrode (8) first electrode / positive Hole injection layer / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / second electrode The order of lamination is such that the first electrode 21 is an anode and the second electrode 31 is a cathode. Also in this embodiment, when the first electrode 21 is used as a cathode and the second electrode 31 is used as an anode, the stacking order of the organic EL layers 43 is reversed.

Also in the present embodiment, the outline of the manufacturing process flow of the organic EL display device 100 is as described with reference to FIG. Even in the present embodiment, when the first electrode 21 is a cathode and the second electrode 31 is an anode, the material and thickness of the first electrode 21 and the second electrode 31 are reversed.

Hereinafter, an example of the organic EL display device 100 having the configuration shown in FIG. 11 will be described as an example, and an outline of the flow of the manufacturing process of the organic EL layer 43 shown in FIG.

<Flow of manufacturing process of organic EL layer 43>
FIG. 12 is a flowchart illustrating an example of a manufacturing process of the organic EL layer 43 illustrated in FIG. 11 in the order of processes.

In the present embodiment, first, as shown in FIG. 12, the support substrate 10 that has been subjected to oxygen plasma treatment as a vacuum bake for dehydration and surface cleaning of the first electrode 21 in step S4 shown in FIG. First, the hole injection layer / hole transport layer 81 (hole injection layer / hole transport layer) is applied to the entire surface of the display region R1 of the support substrate 10 so as to cover the first electrode 21 and the edge cover 15. A pattern is formed by a vacuum deposition method (step S31).

As described above, the hole injection / hole transport layer 81 is uniformly formed over the entire surface of the display region R1 in the support substrate 10. Therefore, like the hole injection layer 22 and the hole transport layer 23 in the first embodiment, film formation is performed using an open mask in which the entire surface of the display region R1 is opened as a mask for vapor deposition.

On the other hand, as described above, in the full-color organic EL display device 100 using the separate coloring method as in the present embodiment, the organic EL element 20 is selectively made to emit light with a desired luminance by using the TFT 12. Display an image.

Therefore, in order to manufacture the organic EL display device 100, it is necessary to form the

light emitting layers

82R, 82G, and 82B made of organic light emitting materials that emit light of each color in a predetermined pattern for each organic EL element 20. .

Therefore, the light-emitting

layers

82R, 82G, and 82B are formed by separate vapor deposition by a vacuum vapor deposition method using a fine mask having an opening only in a region where a light emitting material of a desired display color is vapor-deposited as a vapor deposition mask ( Step S32). Thereby, a pattern film corresponding to each of the sub-pixels 71R, 71G, and 71B is formed.

Thereafter, an electron transport layer / electron injection layer is formed on the support substrate 10 on which the

light emitting layers

82R, 82G, and 82B are formed, using an open mask having the entire display region R1 opened as a mask for vapor deposition, by a vacuum vapor deposition method. 83 (electron transport layer / electron injection layer) (step S33) and the second electrode 31 (step S5) are sequentially formed on the entire surface of the pixel region.

In the present embodiment, a vacuum deposition apparatus similar to the conventional one can be used for the vapor deposition. Note that conditions such as a preferable vacuum arrival rate are as described in the first embodiment. Therefore, the details and illustration of the vacuum vapor deposition apparatus and the vapor deposition method are omitted.

Also in this embodiment, the material and film thickness of the hole injection layer / hole transport layer and electron transport layer / electron injection layer used as the hole injection layer / hole transport layer 81 and the electron transport layer / electron injection layer 83 Is as described in the first embodiment.

Further, the materials of the light emitting layers used as the

light emitting layers

82R, 82G, and 82B are as described in the first embodiment. Each of the

light emitting layers

82R, 82G, and 82B may be made of a single material having a different emission color. A mixed material in which a certain material is used as a host material and another material is mixed as a guest material or a dopant. It may be used.

In this case, the film thickness of the

light emitting layers

82R, 82G, and 82B is, for example, 10 to 100 nm.

In the present embodiment, as shown in FIG. 11, the first electrode 21 has a laminated structure of the reflective electrode layer 111 and the transparent electrode layer 121 as in the first embodiment, so that the organic EL element 20 has a microcavity. The structure is introduced.

For this reason, in the present embodiment, the thicknesses of the

light emitting layers

82R, 82G, and 82B are set to the same thickness. For this reason, the

optical path lengths

73R, 73G, and 73B are set as in the first and second embodiments.

Therefore, the materials and film thicknesses of the hole injection / hole transport layer 81, the electron transport / electron injection layer 83, and the light-emitting

layers

82R, 82G, and 82B can be set in the same manner as in the past. For this reason, in the present embodiment, description of specific materials and film thicknesses of the hole injection layer / hole transport layer 81, the electron transport layer / electron injection layer 83, and the

light emitting layers

82R, 82G, and 82B is omitted. .

<Effect>
As described above, in the present embodiment, as in the first embodiment, the first electrode 21 has a laminated structure of the reflective electrode layer 111 and the transparent electrode layer 121, so that the organic EL element 20 has a microcavity structure. It has been introduced.

Therefore, in the present embodiment, in order to introduce the microcavity structure into the organic EL element 20, it is not necessary to change the film thickness of each of the

light emitting layers

82R, 82G, and 82B for each light emission color.

Therefore, also in this embodiment, the

light emitting layers

82R, 82G, and 82B can be formed to have the same thin film thickness as in the case of using the W light emitting layer as in the first to seventh embodiments. Therefore, the processing tact can be shortened.

Also in the present embodiment, the organic EL element 20 can obtain light in which the microcavity effect is added to the mixture of the light emitted from the

light emitting layers

82R, 82G, and 82B. Further, by adjusting the light by the CF layer 52 provided on the sealing substrate 50, light having a desired spectrum can be extracted to the outside. Therefore, also in this embodiment, color purity can be improved by combining the

light emitting layers

82R, 82G, and 82B, the microcavity effect, and the CF layer 52 using the separate coating method.

Also in the present embodiment, the thickness of the transparent electrode layer 121 in the first electrode 21 is changed for each of the sub-pixels 71R, 71G, and 71B in the same manner as in the first and second embodiments. Needless to say, the same effect as 2 can be obtained.

<Summary>
As described above, in the method for manufacturing a display device according to one embodiment of the present invention, the first transparent electrode layer made of an amorphous transparent electrode material is formed over the reflective electrode layer and etched together. After that, the first transparent electrode layer made of the amorphous transparent electrode material is converted into the first transparent electrode layer made of the polycrystalline transparent electrode material, and the second transparent electrode layer formed thereon is formed. This is a method of changing the total film thickness of the transparent electrode layer between the sub-pixels by laminating the transparent electrode layer using the difference in etching resistance.

Therefore, in the method for manufacturing a display device according to one embodiment of the present invention, one electrode of the pair of electrodes that form an electric field in each subpixel is formed on the reflective electrode layer and the reflective electrode layer. At least one transparent electrode layer, and a plurality of the transparent electrode layers are formed on the reflective electrode layer in at least one sub-pixel, and the entire transparent electrode layer is arranged between sub-pixels having different display colors. A method of manufacturing a display device having different film thicknesses, the step of forming a reflective electrode layer, and the formation of a first transparent electrode layer made of an amorphous transparent electrode material above the reflective electrode layer A first transparent electrode layer forming step, and a patterning step of patterning the first transparent electrode layer made of the amorphous transparent electrode material and the reflective electrode layer together by photolithography. A first transparent electrode layer crystal that crystallizes the first transparent electrode layer made of the amorphous transparent electrode material patterned in the patterning step and converts it into a first transparent electrode layer made of a polycrystalline transparent electrode material. And a second electrode made of a transparent electrode material having lower etching resistance than the first transparent electrode layer made of the polycrystalline transparent electrode material on the first transparent electrode layer made of the polycrystalline transparent electrode material. And a second transparent electrode layer stacking step of selectively etching and patterning the second transparent electrode layer by photolithography.

According to the above method, the transparent electrode layer is laminated on the reflective electrode layer in each subpixel, and the film thickness of the transparent electrode layer on the reflective electrode layer is arbitrarily changed between the subpixels having different display colors. In addition to providing a practical method for manufacturing a display device, the number of times of photolithography can be reduced.

Further, in the display device manufacturing method, the second transparent electrode layer stacking step is performed a plurality of times by changing subpixels forming the resist pattern, and the second transparent electrode layer is selected by photolithography. When patterning is performed by etching, a resist pattern is formed only on one subpixel, and the second transparent electrode layer is etched using the resist pattern as a mask. It is preferable to include the process of forming the pattern of 2 transparent electrode layers.

According to the above method, as described above, the number of photolithography required to change the total film thickness of the transparent electrode layer is two photolithography, and the total film thickness of the transparent electrode layer is The thickness of the second transparent electrode layer in any sub-pixel can be set independently of the thickness of the second transparent electrode layer in other sub-pixels. It becomes possible.

According to the above method, as described above, by including the step of forming the pattern of the second transparent electrode layer only on the one sub-pixel, the optical path length is restricted as in Patent Document 3. In addition, the optical path length in each sub-pixel can be adjusted arbitrarily and easily.

In the method for manufacturing the display device, the second transparent electrode layer is a transparent electrode layer made of an amorphous transparent electrode material, and the second transparent electrode layer laminating step includes the amorphous electrode layer. A second transparent electrode layer forming step for forming a second transparent electrode layer made of a transparent electrode material, and patterning by etching the second transparent electrode layer made of the amorphous transparent electrode material by photolithography The second transparent electrode layer patterning step and the patterned second transparent electrode layer made of the amorphous transparent electrode material are crystallized to be converted into a second transparent electrode layer made of a polycrystalline transparent electrode material. A second transparent electrode layer crystallization step, and in the second transparent electrode layer laminating step, the second transparent electrode layer forming step, the second transparent electrode layer patterning step, and a second transparent Repeat the electrode layer crystallization process. In Succoth, to any sub-pixel, it is preferable that the transparent electrode layer made of a transparent electrode material polycrystalline be any number lamination.

According to the above method, as described above, the transparent electrode layer using the difference in etching selectivity between the transparent electrode layer made of an amorphous transparent electrode material and the transparent electrode layer made of a polycrystalline transparent electrode material is used. Stack up.

According to the above method, the film thickness of each transparent electrode layer can be set independently of the film thickness of the transparent electrode layer in other subpixels, and the optical path length in each subpixel can be set arbitrarily and It can be adjusted easily.

In the display device manufacturing method, the first and second transparent electrode layers are preferably indium tin oxide.

Amorphous indium tin oxide can be easily converted to polycrystalline indium tin oxide by heat treatment. The polycrystalline indium tin oxide has higher etching resistance than the amorphous indium tin oxide, and the amorphous indium tin oxide etching step (second transparent electrode layer patterning step, second transparent electrode layer lamination) In step (5), etching is not performed or the etching rate is extremely low. For this reason, only the amorphous indium tin oxide can be selectively etched in the etching process of amorphous indium tin oxide.

In the second transparent electrode layer patterning step, the reflective electrode layer and the polycrystalline transparent electrode material are formed on the second transparent electrode layer made of the amorphous transparent electrode material in a plan view. A resist pattern is formed which overlaps with the first transparent electrode layer and is larger than the first transparent electrode layer made of the reflective electrode layer and the polycrystalline transparent electrode material in plan view, the resist pattern It is preferable that the second transparent electrode layer is etched and patterned using as a mask.

Depending on the type of the reflective electrode material, if the reflective electrode layer is in an exposed state (that is, an exposed state), for example, when ultraviolet irradiation is performed to increase the wettability of the resist, it is oxidized and the reflection specification is reduced. The solvent resistance is low, and there is a possibility that the solvent may penetrate. For this reason, when such a reflective electrode layer consists of such a reflective electrode material, it is not desirable that the reflective electrode layer is exposed.

However, according to the above configuration, since the reflective electrode layer can be surrounded by the first transparent electrode layer and the second transparent electrode layer made of a polycrystalline transparent electrode material, at the time of manufacturing the display device, The reflective electrode layer can be protected from the above factors that may impair the quality of the reflective electrode layer.

In the display device manufacturing method, the second transparent electrode layer is preferably a layer made of a transparent electrode material having a composition different from that of the first transparent electrode layer.

According to said method, the 1st transparent electrode layer which consists of a polycrystalline transparent electrode material, without converting the transparent electrode layer which consists of an amorphous transparent electrode material into the transparent electrode layer which consists of a polycrystalline transparent electrode material The transparent electrode layers can be stacked using the difference in etching selectivity due to the difference in etching resistance between the second transparent electrode layer and the second transparent electrode layer.

In this case, it is preferable that the first transparent electrode layer is indium tin oxide and the second transparent electrode layer is indium zinc oxide.

Amorphous indium tin oxide can be easily converted to polycrystalline indium tin oxide by heat treatment. Polycrystalline indium tin oxide has higher etching resistance than indium zinc oxide, and when etching indium zinc oxide in the second transparent electrode layer etching step (second transparent electrode layer stacking step), It is not etched or the etching rate is extremely slow. For this reason, in the etching process of the second transparent electrode layer, only the second transparent electrode layer made of indium zinc oxide is selectively etched.

In the second transparent electrode layer laminating step, the reflective electrode layer and the first transparent electrode layer made of the polycrystalline transparent electrode material are overlapped with each other in a plan view, and the reflective electrode layer is seen in a plan view. The second transparent electrode layer is preferably etched using a resist pattern formed larger than the first transparent electrode layer made of the polycrystalline transparent electrode material as a mask.

Also in this case, the reflective electrode layer can be surrounded by a first transparent electrode layer and a second transparent electrode layer made of a polycrystalline transparent electrode material.

In the display device manufacturing method, the reflective electrode layer is preferably made of any one selected from the group consisting of silver, a silver alloy, and an aluminum alloy.

These materials do not cause an electrolytic corrosion reaction with the amorphous transparent electrode layer. For this reason, it is suitable for the reflective electrode material in the reflective electrode layer.

In the method for manufacturing the display device, the pair of electrodes is an anode and a cathode, the one electrode is an anode, and the anode, the cathode, and the anode, the cathode, and the organic electroluminescence layer are sandwiched between the anode and the cathode. It is preferable to form an organic electroluminescence layer.

According to the above method, the optical path length of the organic electroluminescence element in which the organic electroluminescence layer is sandwiched between the anode and the cathode can be easily changed for each sub-pixel having a different emission color.

Therefore, according to the above method, an organic electroluminescence element having a microcavity structure can be obtained. Therefore, due to the microcavity effect, color purity, light emission chromaticity, light emission efficiency, and the like in a display device using the organic electroluminescence element can be improved.

As described above, in the display device according to one embodiment of the present invention, one electrode of the pair of electrodes forming an electric field in each subpixel is formed on the reflective electrode layer and the reflective electrode layer. A plurality of transparent electrode layers are formed on the reflective electrode layer in at least one subpixel, and the entire transparent electrode layer is arranged between subpixels having different display colors. The plurality of transparent electrode layers have different compositions, and the etching resistance of the lower transparent electrode layer is higher than the etching resistance of the upper transparent electrode layer.

According to the above configuration, it is possible to provide a display device that can be manufactured by a practical method while the film thickness of the transparent electrode layer is different for each sub-pixel having a different display color.

In the display device, the lower transparent electrode layer is preferably made of polycrystalline indium tin oxide, and the upper transparent electrode layer is preferably made of indium zinc oxide.

Amorphous indium tin oxide can be easily converted to polycrystalline indium tin oxide by heat treatment. Polycrystalline indium tin oxide has higher etching resistance than indium zinc oxide, and is not etched or has a significantly slower etching rate when etching indium zinc oxide. For this reason, only the transparent electrode layer made of indium zinc oxide can be selectively etched.

Therefore, according to the above configuration, it is possible to provide a display device that can be manufactured by a practical method while the film thickness of the transparent electrode layer is different for each sub-pixel having a different display color.

In the display device, the reflective electrode layer is preferably made of any one selected from the group consisting of silver, a silver alloy, and an aluminum alloy.

As described above, when transparent electrode materials having different compositions and different etching resistance are used for the lower transparent electrode layer and the upper transparent electrode layer, depending on the combination of the transparent electrode material and the reflective electrode material, There is a possibility that an electrolytic corrosion reaction may occur.

However, when the reflective electrode layer is made of the reflective electrode material, there is no such fear. Therefore, the reflective electrode material is suitable for the reflective electrode material in the reflective electrode layer.

In the display device, it is preferable that the upper transparent electrode layer covers a surface of the lower transparent electrode layer and a side surface of the reflective electrode layer.

However, according to the above configuration, it is possible to protect the reflective electrode layer from the above factors that may impair the quality of the reflective electrode layer when the display device is manufactured.

Therefore, according to the above configuration, it is possible to provide a display device having a reflective electrode layer with excellent reflection characteristics.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

The present invention can be suitably used for a display device using a light emitting element that can be configured as a microresonator such as an organic EL element or an inorganic EL element, and a manufacturing method thereof.

1 Organic EL Display Panel 2 Electrical Wiring Terminal 10 Support Substrate 11 Insulating Substrate 12 TFT
13 Interlayer Insulating Film 13a Contact Hole 14 Signal Line 15 Edge Cover 15R / 15G / 15B Opening 20 Organic EL Element 21 First Electrode 22 Hole Injection Layer 23 Hole Transport Layer 24 First Light-Emitting Layer 25 Electron Transport Layer 26 Carrier Generation Layer 27 hole transport layer 28 second light emitting layer 29 electron transport layer 30 electron injection layer 31 second electrode 41 sealing resin layer 42 filling resin layer 43 organic EL layer 50 sealing substrate 51 insulating substrate 52 CF layer 53 BM
60 connection portion 70 pixel 71 sub pixel 71R / 71G / 71B sub pixel 72 light emitting region 73R / 73G / 73B optical path length 81 hole injection layer / hole transport layer 82R / 82G / 82B light emission layer 83 electron transport layer / electron injection layer 100 Organic EL display device 101 Pixel unit 102 Circuit unit 103 Connection terminal 110 a-ITO layer 111 Reflective electrode layer 112 a-ITO layer 113 p-ITO layer 114 p-ITO layer 115 a-ITO layer 116 p-ITO layer 117 a- ITO layer 118 p-ITO layer 121 Transparent electrode layer 131 IZO layer 132 IZO layer 201R / 201G / 201B Resist pattern 211R / 211G / 211B Resist pattern L Sealing area R1 Display area R2 Second electrode connection area R3 Terminal area

Claims

In each subpixel, one of the pair of electrodes forming an electric field includes a reflective electrode layer and at least one transparent electrode layer formed on the reflective electrode layer, and at least one subpixel. A plurality of the transparent electrode layers are formed on the reflective electrode layer, and a method of manufacturing a display device in which the entire film thickness of the transparent electrode layer is different between sub-pixels having different display colors,
Forming a reflective electrode layer;
A first transparent electrode layer forming step of forming a first transparent electrode layer made of an amorphous transparent electrode material above the reflective electrode layer;
A patterning step of patterning the first transparent electrode layer made of the amorphous transparent electrode material and the reflective electrode layer by etching together by photolithography;
A first transparent electrode layer crystal that crystallizes the first transparent electrode layer made of the amorphous transparent electrode material patterned in the patterning step and converts it into a first transparent electrode layer made of a polycrystalline transparent electrode material. Conversion process,
A second transparent electrode layer made of a transparent electrode material having lower etching resistance than the first transparent electrode layer made of the polycrystalline transparent electrode material on the first transparent electrode layer made of the polycrystalline transparent electrode material. And a second transparent electrode layer stacking step of selectively etching and patterning the second transparent electrode layer by photolithography.
The second transparent electrode layer laminating step is performed a plurality of times by changing subpixels for forming a resist pattern, and when the second transparent electrode layer is selectively etched and patterned by photolithography, A resist pattern is formed only on one subpixel, and the second transparent electrode layer is etched using the resist pattern as a mask, thereby forming the pattern of the second transparent electrode layer only on the one subpixel. The method for manufacturing a display device according to claim 1, further comprising a step.
The second transparent electrode layer is a transparent electrode layer made of an amorphous transparent electrode material,
The second transparent electrode layer lamination step includes
A second transparent electrode layer film forming step of forming a second transparent electrode layer made of the amorphous transparent electrode material;
A second transparent electrode layer patterning step of patterning the second transparent electrode layer made of the amorphous transparent electrode material by etching by photolithography;
A second transparent electrode layer crystallization step of crystallizing the patterned second transparent electrode layer made of the amorphous transparent electrode material into a second transparent electrode layer made of a polycrystalline transparent electrode material; Prepared,
In the second transparent electrode layer laminating step, the second transparent electrode layer forming step, the second transparent electrode layer patterning step, and the second transparent electrode layer crystallization step are repeated, so that an arbitrary 3. The method for manufacturing a display device according to claim 1, wherein an arbitrary number of transparent electrode layers made of a polycrystalline transparent electrode material are laminated on the sub-pixel.
4. The method for manufacturing a display device according to claim 3, wherein the first and second transparent electrode layers are indium tin oxide.
In the second transparent electrode layer patterning step, the first electrode made of the reflective electrode layer and the polycrystalline transparent electrode material in a plan view on the second transparent electrode layer made of the amorphous transparent electrode material. And forming a resist pattern which is larger than the reflective electrode layer and the first transparent electrode layer made of the polycrystalline transparent electrode material in a plan view, and masks the resist pattern. 5. The method of manufacturing a display device according to claim 3, wherein the second transparent electrode layer is patterned by etching.
3. The method for manufacturing a display device according to claim 1, wherein the second transparent electrode layer is a layer made of a transparent electrode material having a composition different from that of the first transparent electrode layer.
The method for manufacturing a display device according to claim 6, wherein the first transparent electrode layer is indium tin oxide and the second transparent electrode layer is indium zinc oxide.
In the second transparent electrode layer stacking step, the reflective electrode layer and the first transparent electrode layer made of the polycrystalline transparent electrode material are overlapped with each other in a plan view, and the reflective electrode layer and the above in a plan view The second transparent electrode layer is etched using a resist pattern formed larger than the first transparent electrode layer made of a polycrystalline transparent electrode material as a mask. Manufacturing method of display device.
The method for manufacturing a display device according to any one of claims 1 to 8, wherein the reflective electrode layer is made of any one selected from the group consisting of silver, a silver alloy, and an aluminum alloy.
The pair of electrodes is an anode and a cathode, and the one electrode is an anode,
10. The method of manufacturing a display device according to claim 1, wherein the anode, the cathode, and the organic electroluminescence layer are formed so that the organic electroluminescence layer is sandwiched between the anode and the cathode. .
In each subpixel, one of the pair of electrodes forming an electric field includes a reflective electrode layer and at least one transparent electrode layer formed on the reflective electrode layer, and at least one subpixel. A plurality of the transparent electrode layers are formed on the reflective electrode layer in the display device, and the overall film thickness of the transparent electrode layer is different between sub-pixels having different display colors,
The plurality of transparent electrode layers have different compositions, and the etching resistance of the lower transparent electrode layer is higher than the etching resistance of the upper transparent electrode layer.
12. The display device according to claim 11, wherein the lower transparent electrode layer is made of polycrystalline indium tin oxide, and the upper transparent electrode layer is made of indium zinc oxide.
The display device according to claim 11 or 12, wherein the reflective electrode layer is made of any one selected from the group consisting of silver, a silver alloy, and an aluminum alloy.
14. The display device according to claim 11, wherein the upper transparent electrode layer covers a surface of the lower transparent electrode layer and a side surface of the reflective electrode layer.