TW201351636A - Method for making a display device - Google Patents

Abstract

This invention provides a method for making a display device, the method being capable of forming an organic thin film layer with a uniform film thickness without undergoing an oxygen plasma processing. The display device contains a supporting substrate, partition walls, and a plurality of organic EL elements; each organic EL element contains sequentially from the supporting substrate side first electrodes, an organic thin film layer, and second electrodes. The method includes the step of preparing the partition walls by pattern forming a photosensitive resin composition containing a liquid repelling agent according to a photolithography, and a supporting substrate having first electrodes provided thereon, the step of cleaning the surface of the first electrodes with a solution containing at least an oxalic acid, a phosphoric acid, an acetic acid, a nitric acid, and hydrochloride, or a developing liquid for developing the photosensitive resin composition, the step of forming an organic thin film layer on the first electrodes with a coating method, and the step of forming the second electrodes on the organic thin film layer.

Description

Display device manufacturing method

The present invention relates to a method of manufacturing a display device.

One of the display devices is a display device that uses an organic electroluminescence element (hereinafter sometimes referred to as an "organic EL element") as a light source of a pixel. The configuration of the organic EL element used in the pixel is a micro-recess structure (microresonator structure) (for example, refer to Patent Document 1). By adopting such a configuration, it is possible to achieve an improvement in color purity and a high luminance in a predetermined viewing angle range.

(previous technical literature)

(Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. 2002-367770

In the above display device, a plurality of organic EL elements corresponding to pixels are arranged in a row on a predetermined support substrate. Further, on the support substrate, a partition wall for dividing a predetermined partition is provided, and a plurality of organic EL elements are respectively arranged in a region partitioned by the partition walls.

Each of the organic EL elements is formed by sequentially laminating a first electrode, an organic thin film layer, and a second electrode region from the side of the support substrate.

The organic thin film layer of the organic EL element can be formed, for example, by a coating method. The method of forming the organic thin film layer will be described below with reference to Fig. 13. As shown in FIG. 13A, first, the support substrate 12 on which the first electrode 16 and the partition wall 13 are formed is prepared. Next, on the support substrate 12, the ink 17 containing the material which becomes the organic thin film layer 18 is supplied to the region (concave portion) 15 surrounded by the partition wall 13. The supplied ink 17 is accommodated in a region 15 surrounded by the partition wall 13 (refer to Fig. 13B). Then, the organic thin film layer 18 is formed by vaporizing the solvent of the ink 17 (refer to Fig. 13C).

Further, when the partition wall 13 exhibits lyophilicity to the ink 17, the ink supplied to the specific partition wall 13 is transmitted on the surface of the partition wall 13, and sometimes overflows to the adjacent recess 15. In order to prevent the outflow of the ink, it is necessary to impart a certain degree of liquid repellency to the partition wall 13.

Therefore, for example, after forming the partition wall, the partition wall may be subjected to plasma treatment of fluorine gas to impart liquid repellency to the partition wall 13. However, in this method, the organic thin film layer is contaminated due to the reaction product of fluorine gas, and the characteristics of the organic EL element are deteriorated.

Therefore, there is also a method of forming a partition wall by using a photosensitive resin composition containing a liquid-repellent agent, and imparting liquid repellency to the partition wall without applying a plasma treatment of fluorine gas.

When the organic thin film layer is formed by the above method using such a partition wall, there is a problem that it is not necessary to form an organic thin film layer having a uniform film thickness.

When an organic thin film layer having a non-uniform film thickness is formed, current flows in a portion where the film thickness is thin, and uniform light emission cannot be obtained. Further, in the above-described micro-pit structure, although the film thickness of each organic thin film layer is set in accordance with the light-emitting wavelength, there is a problem that an organic thin film layer having a desired film thickness cannot be obtained, and desired characteristics cannot be obtained. In the micro-pit structure, since the film thickness of the organic thin film layer greatly affects the element characteristics, it is more particularly required to improve the in-plane uniformity of the film thickness.

The in-plane uniformity of the film thickness of the organic thin film layer is lowered, and it can be regarded as uneven wettability on the first electrode. For example, when a portion having poor wettability is locally present on the first electrode, since the ink is peeled off at this portion and thinned, the in-plane uniformity of the film thickness is lowered. Therefore, a treatment for improving the wettability on the first electrode before the application of the ink can be considered. For example, the wettability on the first electrode can be improved by oxygen plasma treatment. As described above, when the ink is supplied after the wettability of the first electrode is increased, the ink can be wetted and diffused on the first electrode to obtain an organic thin film layer having a uniform film thickness. However, when the oxygen plasma treatment is performed, the surface of the partition wall is etched to cause unevenness in the film thickness of the partition wall of the region, and the liquid repellency of the partition wall is lowered. As a result, the ink supplied to the concave portion (the region partitioned by the partition wall) sometimes overflows, causing a problem that the organic EL element cannot be formed as designed.

Accordingly, an object of the present invention is to provide a method of manufacturing a display device capable of forming an organic thin film layer with a uniform film thickness without performing oxygen plasma treatment or the like.

The present invention relates to a method of manufacturing a display device, comprising: a support substrate, a partition wall dividing a predetermined separation area on the support substrate, and a plurality of partitions respectively disposed on the partition divided by the partition wall of the partition a method of manufacturing a display device including a first electrode, an organic thin film layer, and a second electrode in order from the support substrate side, wherein the organic EL device includes a step of preparing a support substrate, and a top portion of the support substrate Provided is a partition wall formed by patterning a photosensitive resin composition containing a liquid repellent by a lithography technique, and a first electrode; and containing at least one of oxalic acid, phosphoric acid, acetic acid, nitric acid, and hydrochloric acid And a developing solution for the photosensitive resin composition to wash the surface of the first electrode; a step of forming an organic thin film layer by the coating method on the first electrode; and the organic thin film layer The step of forming the second electrode thereon.

Further, in each of the organic EL elements, the first electrode may be a single layer or two or more layers, and the organic thin film layer may be a single layer or two or more layers, and the second electrode may be a single layer or two or more layers.

According to the invention, the surface of the first electrode is washed by a solution containing at least one of oxalic acid, phosphoric acid, acetic acid, nitric acid, and hydrochloric acid or a developing solution for forming a photosensitive resin composition which is a partition wall. Instead of performing the oxygen plasma treatment, the wettability of the surface of the first electrode can be improved, and the wetting is performed on the entire surface of the first electrode. Sexual homogenization. Thus, the organic thin film layer can be formed with a uniform film thickness without performing oxygen plasma treatment or the like.

1‧‧‧ display device

2‧‧‧Support substrate

3‧‧‧ next door

End of the next door to the 3a‧‧

4‧‧‧Organic EL components

5‧‧‧ recess

6‧‧‧1st electrode

7‧‧‧1st organic film layer (hole injection layer)

8‧‧‧ partition film for partition formation

9‧‧‧2nd organic film layer (light-emitting layer)

10‧‧‧2nd electrode

12‧‧‧Support substrate

13‧‧‧ next door

15‧‧‧ recess

16‧‧‧1st electrode

17‧‧‧Ink

18‧‧‧Organic film layer

19‧‧‧Residue

21‧‧‧Photomask

22‧‧‧Ink

Fig. 1 is a view schematically showing a part of a display device 1 according to an embodiment of the present invention.

Fig. 2 is a plan view schematically showing a part of the display device 1 according to an embodiment of the present invention.

Fig. 3A is a view for explaining a method of manufacturing a display device according to an embodiment of the present invention.

Fig. 3B is a view for explaining a method of manufacturing a display device according to an embodiment of the present invention.

Fig. 3C is a view for explaining a method of manufacturing a display device according to an embodiment of the present invention.

Fig. 4A is a view for explaining a method of manufacturing a display device according to an embodiment of the present invention.

Fig. 4B is a view for explaining a method of manufacturing a display device according to an embodiment of the present invention.

Fig. 4C is a view for explaining a method of manufacturing a display device according to an embodiment of the present invention.

Fig. 5A is a view for explaining a method of manufacturing a display device according to an embodiment of the present invention.

Fig. 5B is a view for explaining a method of manufacturing a display device according to an embodiment of the present invention.

Fig. 5C is a view for explaining a method of manufacturing a display device according to an embodiment of the present invention.

Fig. 6 is a plan view schematically showing a part of the display device 1 according to an embodiment of the present invention.

Fig. 7 is a view schematically showing a part of the display device 1 according to an embodiment of the present invention.

Fig. 8 is a view showing the PL spectrum of the luminescent material used in the calculation of Fig. 9.

Fig. 9 is a graph showing the film thickness dependence of the hole injection layer of the EL spectrum in the micro-pit structure.

Fig. 10 is a view showing the EL spectrum of the organic EL device produced by the production method of the present invention and the PL spectrum of the luminescent material.

Fig. 11 is a view showing the EL spectrum of the organic EL device produced by the production method of the present invention and the PL spectrum of the luminescent material.

Fig. 12 is a view showing the EL spectrum of the organic EL device produced by the production method of the present invention and the PL spectrum of the luminescent material.

Fig. 13A is a view for explaining a method of manufacturing the display device.

Fig. 13B is a view for explaining a method of manufacturing the display device.

Fig. 13C is a view for explaining a method of manufacturing the display device.

Embodiments of the present invention will be described in more detail below with reference to the drawings. For ease of understanding, the scale of each component in the drawing is sometimes different from the actual one. In the display device, there are also lead wires and the like of the electrodes, but since they are not directly related in the description of the present invention, the description thereof is omitted. on Although the description of the layer structure and the like is simple, in the following examples, the support substrate is arranged downward, but the display device of the present invention is not necessarily disposed in the vertical and horizontal directions. It is not limited to the form of manufacturing or use, and can be appropriately adjusted.

The present invention relates to a method of manufacturing a display device, comprising: a support substrate, a partition wall dividing a predetermined separation area on the support substrate, and a plurality of partitions respectively disposed on the partition divided by the partition wall of the partition a method of manufacturing a display device including a first electrode, an organic thin film layer, and a second electrode, each of which includes a first electrode, an organic thin film layer, and a second electrode, wherein the organic EL device includes a step of preparing a support substrate, and a top surface of the support substrate Provided is a partition wall formed by patterning a photosensitive resin composition containing a liquid repellent by a lithography technique, and a first electrode; and containing at least one of oxalic acid, phosphoric acid, acetic acid, nitric acid, and hydrochloric acid And a developing solution for the photosensitive resin composition to wash the surface of the first electrode; a step of forming an organic thin film layer by the coating method on the first electrode; and the organic thin film layer The step of forming the second electrode thereon.

The display device mainly includes an active matrix drive type device and a passive matrix drive type device. The present invention can be applied to the display devices of the two types of driving. However, in the present embodiment, the display device is applied to an active matrix driving type display device as an example.

<Configuration of display device>

First, the configuration of the display device will be described. Fig. 1 is a view schematically showing a part of the display device 1 of the present embodiment. Figure 2 shows the enlargement A plan view schematically showing a part of the display device 1 of the embodiment. The display device 1 mainly includes a support substrate 2, a partition wall 3 that partitions a predetermined partition area on the support substrate 2, and a plurality of organic EL elements respectively disposed on the partitions partitioned by the partition walls 3. 4.

The partition wall 3 is formed, for example, in a checkered or elongated shape on the support substrate 2. Moreover, in the second drawing, the display device 1 provided with the square partition 3 is shown as an embodiment. In Fig. 2, the region where the hatching is applied corresponds to the partition wall 3.

A plurality of recesses 5 defined by the partition walls 3 and the support substrate 2 are set on the support substrate 2. This recess 5 corresponds to a partition divided by the partition wall 3.

The partition wall 3 of the present embodiment is formed in a checkered shape. Therefore, when viewed from one of the thickness directions Z of the support substrate 2 (hereinafter sometimes referred to as "viewing in plan view"), the plurality of recesses 5 are arranged in a matrix. That is, the concave portions 5 are arranged at a predetermined interval in the column direction X and are also arranged at a predetermined interval in the row direction Y. The shape of each recessed portion 5 in a plan view is not particularly limited. For example, the recess 5 may be formed in a shape of a substantially rectangular shape, a substantially elliptical shape, or a small elliptical shape when viewed in plan. In the present embodiment, a concave portion 5 having a substantially rectangular shape in plan view is provided. In the present specification, the column direction X and the row direction Y mean a direction perpendicular to the thickness direction Z of the support substrate 2, and are perpendicular to each other.

The partition wall 3 of the present embodiment has a so-called forward tapered shape. That is, the partition wall 3 of the present embodiment gradually tapers away from the support substrate 2. For example, perpendicular to the direction of extension (row direction Y) The cross-sectional shape when the plane is cut in the row direction Y in the row direction Y is formed to be gradually tapered as it is away from the support substrate 2. In Fig. 1, a partition wall having a substantially isosceles trapeze shape is shown. When the upper bottom and the lower bottom of the support substrate side are compared, the width of the lower bottom is wider than the upper base. Further, the cross section of the partition wall actually formed does not necessarily have to be a trapezoidal shape, and the straight portion and the angle of the trapezoidal shape may have a rounded portion and are formed in a so-called semicircular shape (dome shape).

In the present embodiment, the partition wall 3 is mainly provided in a region where the region where the organic EL element is provided is subtracted. In addition, the partition wall 3 is mainly provided in a region where the region where the first electrode 6 to be described later is provided is deducted, and is also formed on the peripheral edge portion of the first electrode 6 so that the end portion 3a is superposed on the first electrode 6. Further, the end portion 3a of the partition wall 3 is not required to cover the entire peripheral portion of the first electrode 6. For example, when forming the elongated partition wall 3 to be described later, the partition wall may be formed so that the end portion of the partition wall covers the two opposite sides of the four sides of the first electrode 6. In the present embodiment, the end portion 3a of the partition wall 3 is formed to cover the entire peripheral edge portion of the first electrode 6.

Further, as another embodiment, an insulating film having an opening in the first electrode may be further provided between the partition wall and the support substrate.

The organic EL element 4 is disposed in a partition (i.e., the recess 5) partitioned by the partition wall 3. As in the present embodiment, when the square partition walls 3 are provided, the respective organic EL elements 4 are provided in the respective concave portions 5. Therefore, the organic EL element 4 is arranged in a matrix shape in the same manner as each of the concave portions 5, and The support substrate 2 is arranged in the column direction X at a predetermined interval and in the row direction Y at a predetermined interval.

In the present embodiment, three kinds of organic EL elements 4 are provided. That is, (1) a red organic EL element 4R that emits red light, (2) a green organic EL element 4G that emits green light, and (3) a blue organic EL element 4B that emits blue light. The three kinds of organic EL elements 4R, 4G, and 4B can be arranged, for example, by sequentially arranging the following columns (I), (II), and (III) in the row direction Y (see FIG. 2). .

(I) A row of the red organic EL elements 4R is arranged at a predetermined interval in the column direction X.

(II) The green organic EL element 4G is arranged in a row at a predetermined interval in the column direction X.

(III) The blue organic EL elements 4B_ are arranged at predetermined intervals in the column direction X.

Further, as another embodiment, in addition to the above-described three types of organic EL elements, for example, an organic EL element that emits white light may be further provided. Further, a monochrome display device can be realized by one type of organic EL element.

The organic EL element 4 is formed by sequentially laminating a first electrode, an organic thin film layer, and a second electrode from the side of the support substrate 2. In the present specification, a layer containing an organic substance in a layer provided between the first electrode 6 and the second electrode 10 is referred to as an organic thin film layer. The organic EL element 4 is provided with at least one light-emitting layer as an organic thin film layer. Further, in addition to the one-layer light-emitting layer, the organic EL element may further have an organic layer different from the light-emitting layer. Thin film layer or inorganic layer. For example, a hole injection layer, a hole transport layer, an electron blocking layer, an electron transport layer, an electron injection layer, and the like may be provided between the first electrode 6 and the second electrode 10. Further, two or more light-emitting layers may be provided between the first electrode 6 and the second electrode 10. In the organic EL element 4, the first electrode may be a single layer or a double layer or more, and the organic thin film layer may be a single layer or a double layer or more, and the second electrode may be a single layer or a double layer or more.

The organic EL element 4 includes a first electrode 6 and a second electrode 10 as a counter electrode formed of an anode and a cathode. One of the first electrode 6 and the second electrode 10 is an anode, and the other electrode is a cathode.

In the present embodiment, a first electrode 6 having a function of an anode, a first organic thin film layer 7 having a function of a hole injection layer, and a function of a light-emitting layer are sequentially formed on the support substrate 2 as an example. The second organic thin film layer 9 and the organic EL element 4 having the second electrode 10 having a function as a cathode.

In the present embodiment, three kinds of organic EL elements are provided, but these are different from the configuration of the second organic thin film layer (the light-emitting layer in the present embodiment) 9, respectively. The red organic EL element 4R has a red light-emitting layer 9 that emits red light. The green organic EL element 4G has a green light-emitting layer 9 that emits green light. The blue organic EL element 4B is provided with a blue light-emitting layer 9 that emits blue light.

In the present embodiment, the first electrode 6 is provided in each of the organic EL elements 4. That is, the same number of first electrodes 6 as the organic EL elements 4 are provided on the support substrate 2. The first electrode 6 corresponds to the organic EL element The arrangement of the members 4 is provided in the same manner as the organic EL element 4, and is arranged in a matrix. Further, the partition wall 3 of the present embodiment is mainly formed in a checkered shape in a region where the first electrode 6 is subtracted, but the end portion 3a is further formed to cover the peripheral edge portion of the first electrode 6 (refer to the first Figure).

The first organic thin film layer 7 having the function of the hole injection layer is provided on the first electrode 6 in the recess 5. The first organic thin film layer 7 may be provided such that the material or film thickness differs depending on the type of the organic EL element as necessary. From the viewpoint of the ease of the formation step of the first organic thin film layer 7, all of the first organic thin film layers 7 can be formed of the same material and film thickness. Further, when an organic EL element having a micro-pit structure as described later is formed, the film thickness of the first organic thin film layer 7 is adjusted in accordance with the type of the organic EL element so as to cause optical resonance.

The second organic thin film layer 9 having a function as a light-emitting layer is provided on the first organic thin film layer 7 in the concave portion 5. As described above, the light-emitting layer is provided in accordance with the type of the organic EL element. Therefore, the red light-emitting layer 9 is provided in the recess 5 provided with the red organic EL element 4R. The green light-emitting layer 9 is provided in the recess 5 provided with the green organic EL element 4G. The blue light-emitting layer 9 is provided in the recess 5 provided with the blue organic EL element 4B.

The second electrode system is provided on the organic thin film layer. However, in the present specification, the layer "on" is provided in a form in which the contact is provided in the lower layer and in a state in which the lower layer is separated from the lower layer. For example, a predetermined inorganic layer may be provided between the organic thin film layer and the second electrode provided above.

In the embodiment, the second electrode 10 is formed in the setting There is a display area of the organic EL element 4 in its entirety. In other words, the second electrode 10 is formed not only on the second organic thin film layer 9, but also on the partition wall 3, and covers a plurality of organic EL elements continuously, and is provided as a common electrode of all the organic EL elements 4.

<Method of Manufacturing Display Device>

A method of manufacturing the display device will be described below with reference to FIGS. 3 to 5.

(Steps of preparing the support substrate)

In this step, a support substrate is prepared, and a partition wall formed by patterning a photosensitive resin composition containing a liquid-repellent agent by a lithography technique and a first electrode are provided on the support substrate. In other words, in this step, the liquid-repellent partition wall and the support substrate of the first electrode are prepared above the liquid crystal. In this step, the support substrate on which the partition wall and the first electrode are provided may be prepared in advance, or in this step, the partition wall and the first electrode may be prepared by forming the partition wall and/or the first electrode. Support the substrate. In the case of an active matrix drive type display device, a substrate on which a circuit for individually driving a plurality of organic EL elements is formed in advance can be used as the support substrate 2. For example, a substrate on which a TFT (Thin Film Transistor), a capacitor, or the like is formed in advance can be used as a support substrate.

In the present embodiment, first, a plurality of first electrodes 6 are formed in a matrix on the support substrate 2 (refer to FIG. 3A). The first electrode 6 can be formed, for example, by forming a conductive thin film on one surface of the support substrate 2 and forming a matrix pattern by lithography. Further, for example, a mask having an opening formed at a predetermined portion may be disposed on the support substrate 2 and transmitted through the cover The cover selectively deposits a conductive material on a predetermined portion on the support substrate 2, thereby forming a pattern of the first electrode 6. The material of the first electrode 6 will be described in detail later.

Next, in this step, a pattern of the partition wall is formed by using a photosensitive resin composition containing a liquid repellent and forming a pattern by a lithography technique so that the end portion is in contact with the first electrode. . In the present embodiment, first, a photosensitive resin composition containing a liquid-repellent agent is applied onto the support substrate 2 to form a film for forming a partition wall. The coating method of the photosensitive resin composition may, for example, be a spin coating method or a slit coating method.

After the photosensitive resin composition is applied onto the support substrate, prebaking is usually performed. The support substrate 2 is heated, for example, at a temperature of 80 to 110 ° C for 60 seconds to 180 seconds to thereby perform prebaking to remove the solvent in the photosensitive resin composition (refer to FIG. 3B ).

Next, the photomask 21 for shielding the light of the predetermined pattern is placed on the support substrate 2, and the film 8 for forming the partition wall is exposed through the mask 21. The photosensitive resin composition has a positive and negative photosensitive resin composition, and any of the photosensitive resin compositions can be used in this step. When a positive photosensitive resin composition is used, light is irradiated onto the remaining portion of the film for forming a partition wall 8 other than the portion where the partition wall 3 is to be formed. In addition, when a negative photosensitive resin composition is used, light is irradiated onto a portion of the film for forming a partition wall 8 where the partition wall 3 is mainly formed. In this step, it is explained with reference to FIG. 3C. As shown in FIG. 3C, the photomask 21 is placed on the substrate on which the film for partition wall formation 8 is formed, and is transmitted through the photomask 21. The light is irradiated, whereby the light is irradiated onto the portion of the film for forming the partition wall 8 where the partition wall 3 is mainly formed. In Fig. 3C, the light irradiated on the partition wall forming film 8 is schematically indicated by an arrow mark.

Next, the film for forming the partition wall after the exposure is developed using the developer described later. Thereby, the partition wall 3 is patterned (refer to FIG. 4A). Post-baking after development. The partition wall 3 is hardened by, for example, heating the substrate at a temperature of 200 to 230 ° C for 15 minutes to 60 minutes.

In this manner, by using a photosensitive resin composition containing a liquid repellent and forming a pattern of the partition walls by lithography, a partition wall for imparting liquid repellency can be obtained. The contact angle of the partition wall used in the present embodiment is, for example, preferably from 25 to 60, more preferably from 30 to 45 with respect to the anisole.

As described above, the photosensitive resin composition used for forming the partition walls is of a negative type and a positive type.

(negative photosensitive resin composition)

The negative photosensitive resin composition remains in which the irradiated portion of the light is insoluble in the developer.

The photosensitive resin composition is generally formulated with a binder resin, a crosslinking agent, a photoreaction initiator, a solvent, and other additives.

The binder resin is a polymer that is previously polymerized. In this example, a non-polymerizable binder resin which does not have polymerizability itself, and a polymerizable binder resin which introduces a polymerizable substituent are mentioned. Adhesive resin, based on polystyrene, by gel permeation chromatography (GPC: Gel) Permeation Chromatography) The weight average molecular weight sought is in the range of 5,000 to 400,000.

Examples of the binder resin include a phenol resin, a phenol resin, a melamine resin, an acrylic resin, an epoxy resin, and a polyester resin. As the binder resin, any of a homopolymer and a copolymer of two or more kinds of monomers may be used. The binder resin is usually 5% to 90% by mass based on the total solid content of the photosensitive resin composition.

The crosslinking agent is a compound which can be polymerized by an active radical, an acid or the like generated from a photopolymerization initiator by irradiation of light, and examples thereof include a compound having a polymerizable carbon-carbon unsaturated bond. The crosslinking agent may be a monofunctional compound having one polymerizable carbon-carbon unsaturated bond in the molecule, or a bifunctional or trifunctional or higher polyfunctional having two or more polymerizable carbon-carbon unsaturated bonds. Compound. In the photosensitive resin composition, when the total amount of the binder resin and the crosslinking agent is 100 parts by mass, the crosslinking agent is usually 0.1 parts by mass or more and 70 parts by mass or less. In the photosensitive resin composition, when the total amount of the binder resin and the crosslinking agent is 100 parts by mass, the photoreaction initiator is usually 1 part by mass or more and 30 parts by mass or less.

(Positive photosensitive resin composition)

On the other hand, the positive photosensitive resin composition is one in which the irradiated portion of the light is soluble in the developer. The positive photosensitive resin composition is generally composed of a compound in which a resin is hydrophilized under a photoreaction.

A positive photosensitive resin composition which can be used in combination: phenolic resin, polyhydroxystyrene, acrylic resin, methacrylic acid tree A resin having resistance and adhesion such as lipid or polyimine, and a photodegradable compound.

(liquid dispensing agent)

The liquid-repellent agent contained in the positive- or negative-type photosensitive resin composition may, for example, be a fluorine-containing compound or a polysiloxane-containing compound, and preferably exhibits excellent liquid repellency to an organic solvent. Fluorinated compound.

The fluorine-containing compound may, for example, be a compound having a linear or branched fluoroalkyl group and/or a fluoropolyether group having 1 to 8 carbon atoms. The fluorine-containing compound is preferably a polymer having a crosslinkable group, more preferably a polymer having a fluoroalkyl group and/or a fluoropolyether group having 4 to 6 carbon atoms and having a crosslinkable group. Further, the fluorine-containing compound preferably has a solubility function to the developer. The fluorine-containing compound may be provided with a liquid-repellent property on the surface of the partition wall after the partition wall is formed, and is not limited to a polymer, and may be a low molecular compound.

The crosslinkable group is a group which imparts a crosslinkability to a fluorine-containing compound, and examples thereof include an ethylenically unsaturated bond group, an epoxy group, and a hydroxyl group. The type of the crosslinkable group is not limited to the above, as long as it has a function of being able to crosslink with the photosensitive resin composition used for forming the partition walls.

Specific examples of the liquid-repellent agent include MEGAFAC RS-101, RS-102, RS-105, RS-401, RS-402, RS-501, RS-502, and RS-718 (all manufactured by DIC Corporation). OPTOOL DAC, OPTOACE HP series (above, manufactured by Daikin Industries, Ltd.), perfluoro(meth)acrylate, perfluorodi(meth)acrylate, and the like.

The above liquid repellent may be used alone or in combination of two. Used on. The liquid-repellent agent is usually 0.1 parts by mass or more and 3 parts by mass or less based on the mass fraction of the total solid content of the photosensitive resin composition after the de-liquidizing agent.

(developer)

Examples of the developing solution used for development include a potassium hydroxide aqueous solution, a sodium hydroxide aqueous solution, and a tetramethylammonium hydroxide (TMAH) aqueous solution.

The shape and arrangement of the partition walls 3 can be appropriately set in accordance with the specifications of the display device such as the number of pixels and the resolution, the ease of manufacture, and the like. For example, the width in the column direction X or the row direction Y of the partition walls 3 is about 5 μm to 50 μm, and the height of the partition walls 3 is about 0.5 μm to 5 μm, and adjacent portions in the column direction X or the row direction Y are partition walls. The interval between the three, that is, the width X of the concave portion 5 or the width in the row direction Y is about 10 μm to 500 μm. Further, the width in the column direction X of the first electrode 6 and the row direction Y are each about 10 μm to 500 μm.

(Step of washing the surface of the first electrode)

In this step, the surface of the first electrode is washed (refer to FIGS. 4A and 4B).

As shown in FIG. 4A, the film for forming a partition wall 8 formed on the first electrode 6 is left to adhere to the first electrode 6 and remains even if the developing process is performed using a developing solution. In this step, by washing the surface of the first electrode 6, the residue 19 or the contamination of the partition wall forming film 8 is removed, and the surface of the first electrode 6 is cleaned. Thereby, the wettability of the surface of the first electrode 6 can be improved, and the wettability can be made uniform over the entire surface of the first electrode 6.

In this step, the surface of the first electrode is washed by a solution containing at least one of oxalic acid, phosphoric acid, acetic acid, nitric acid, and hydrochloric acid or a developing solution of the photosensitive resin composition.

In this step, as the developer used for the cleaning, a developer which can be used when the partition walls are formed by the lithography technique can be used. For example, potassium hydroxide, sodium hydroxide or tetramethylammonium hydroxide (TMAH) aqueous solution can be used. By using such a developing solution, the residue 19 of the film for partition wall formation 8 can be removed efficiently. Further, the developer used in this step may be a developer having the same composition as that of the developer used to form the partition walls, or a developer having a different composition. When a developer having a different composition is used, the residue remaining in the development step which cannot be removed can be removed more efficiently.

Further, the concentration of the developer used in this step is preferably lower than the concentration of the developer used in forming the partition walls. For example, when the concentration of the developer used to form the partition wall is A (% by weight), and the concentration of the developer used in this step is B (% by weight), "A/B" is preferably 1 to 25, more preferably 2 to 5. By cleaning the first electrode at this concentration, it is possible to suppress the etching of the partition walls.

In this step, a solution containing at least one of oxalic acid, phosphoric acid, acetic acid, nitric acid, and hydrochloric acid used in the washing may, for example, be a mixed solution of hydrochloric acid and a ferrous chloride solution, a mixed solution of hydrochloric acid and nitric acid, or phosphoric acid. A mixed solution of nitric acid and acetic acid, an aqueous solution of oxalic acid, or the like.

This solution can be selected in accordance with the type of the first electrode. For example, when the first electrode is composed of an ITO (Indium Tin Oxide) film, it is preferred to use a mixture of hydrochloric acid and a ferrous chloride solution. The liquid, a mixed solution of hydrochloric acid and nitric acid, or a mixed solution of phosphoric acid and acetic acid and nitric acid is used for washing, and among these, it is more preferable to use a mixed solution of phosphoric acid and acetic acid and nitric acid to wash. Further, for example, when the first electrode is made of an IZO (Indium Zinc Oxide) film, it is preferred to use a mixed solution of phosphoric acid and acetic acid and nitric acid or an aqueous solution of oxalic acid.

When the first electrode composed of ITO is washed with a mixed solution of hydrochloric acid and a ferrous chloride solution, a mixed solution having a concentration of 5 to 25% by weight of hydrochloric acid and 10 to 30% by weight of ferrous chloride is preferred. More preferably, it is a mixed solution having a concentration of 17.5% by weight of hydrochloric acid and 20% by weight of ferrous chloride. Further, when the first electrode composed of ITO is washed with a mixed solution of phosphoric acid and acetic acid and nitric acid, it is preferably 60 to 80% by weight of phosphoric acid, 0.1 to 20% by weight of acetic acid, and 0.1 to 10% by weight of nitric acid. The mixed solution of the concentration is more preferably a mixed solution having a concentration of 71% by weight of phosphoric acid, 10.5% by weight of acetic acid, and 2.2% by weight of nitric acid.

Further, when the first electrode composed of IZO is washed with a mixed solution of phosphoric acid and acetic acid and nitric acid, it preferably has 0.1 to 20% by weight of phosphoric acid, 0.1 to 10% by weight of acetic acid, and 0.1 to 10% by weight of nitric acid. The mixed solution of the concentration is more preferably a mixed solution having a concentration of 7.1% by weight of phosphoric acid, 1.1% by weight of acetic acid, and 0.2% by weight of nitric acid.

Further, when the first electrode composed of IZO is washed with an aqueous oxalic acid solution, the concentration is preferably from 1 to 10% by weight.

By washing the surface of the first electrode with a solution containing at least one of oxalic acid, phosphoric acid, acetic acid, nitric acid, and hydrochloric acid, the residue 19 or contamination of the film for forming the partition wall 8 can be removed, and the surface of the first electrode 6 may be removed. The face is also etched. Thereby, the wettability of the surface of the first electrode 6 can be improved, and the wettability can be made uniform over the entire surface of the first electrode 6.

As described above, by washing the surface of the first electrode 6, the surface of each of the first electrodes 6 can be uniformly lyophilized. In addition, as long as a solution containing at least one of oxalic acid, phosphoric acid, acetic acid, nitric acid, and hydrochloric acid or a developer containing a photosensitive resin composition for forming a partition wall is brought into contact with the surface of the first electrode, This method is not particularly limited. For example, the surface of the first electrode may be immersed in a solution containing at least one of oxalic acid, phosphoric acid, acetic acid, nitric acid, and hydrochloric acid or a developer of a photosensitive resin composition used for forming a partition wall. Implementation. Alternatively, the cleaning may be applied to the first electrode by a solution containing at least one of oxalic acid, phosphoric acid, acetic acid, nitric acid, and hydrochloric acid or a photosensitive resin composition used for forming a partition wall. The surface is implemented. Alternatively, the cleaning solution may be sprayed to a solution containing at least one of oxalic acid, phosphoric acid, acetic acid, nitric acid, and hydrochloric acid or a developer of a photosensitive resin composition used for forming a partition wall. The surface of the 1 electrode is implemented.

After washing the surface of the first electrode 6 and washing with water, a solution containing at least one of oxalic acid, phosphoric acid, acetic acid, nitric acid, and hydrochloric acid or a developer of the photosensitive resin composition can be removed from the support substrate. . Then it is dried.

(Step of forming an organic thin film layer)

In this step, an organic thin film layer is formed on the first electrode 6 by a coating method. In this step, the organic thin film layer provided in contact with at least the first electrode 6 is formed by a coating method (in the present embodiment, the first organic thin film) Floor). In the present embodiment, the first organic thin film layer 7 and the second organic thin film layer 9 are formed by a coating method.

Further, from the time when the step of cleaning the surface of the first electrode is completed, the ink for forming the organic thin film layer (the first organic thin film layer in the present embodiment) provided in contact with the first electrode 6 is started. The shorter the time from the application of the coating, the better, and more preferably, it is within 2 hours, and more preferably within 30 minutes. Moreover, the point at which the step of washing the surface of the first electrode is completed is the timing at which the drying is completed, and the point at which the application of the ink is started is the time at which the ink is first applied.

In this step, first, the ink 22 containing the material for forming the first organic thin film layer 7 is supplied to a region (recess 5) surrounded by the partition walls 3 (refer to FIG. 4C). The ink can be supplied in the most appropriate manner by considering the shape of the partition 3, the ease of the film formation step, and the film forming property. The ink can be supplied, for example, by an inkjet printing method, a nozzle coating method, a relief printing method, a gravure printing method, or the like.

As shown in Fig. 4C, the ink 22 supplied to the region (recess 5) surrounded by the partition wall 3 is wet-diffused on the first electrode and diffused to the side surface of the partition wall 3, but the partition wall 3 is displayed. The liquid repellency is removed, so that the ink can be prevented from overflowing to the adjacent concave portion. As described above, by providing the partition wall showing the liquid repellency, the ink can be surely accommodated in the region (recess 5) surrounded by the partition wall 3.

Next, the first organic thin film layer 7 is formed by curing the ink 22 (refer to FIG. 5A). The curing of the ink can be carried out, for example, by natural drying, heat drying, vacuum drying, or the like. In addition, when the ink contains When the material to be polymerized is applied by energy, the film may be heated after the ink is supplied or the film may be irradiated onto the film to polymerize the material constituting the organic film layer. By polymerizing the material constituting the organic thin film layer, the ink used in forming the other organic thin film layer (the second organic thin film layer) on the organic thin film layer (the first organic thin film layer) can be used. This first organic thin film layer becomes poorly soluble.

As described above, in the present invention, the wettability of the surface of the first electrode is increased, and the wettability is uniformized on the entire surface of the first electrode. Therefore, the solvent of the ink is vaporized. When the film formation is formed, the ink is not partially removed and can be uniformly held on the first electrode to be dried. Therefore, the first organic thin film layer 7 having a uniform film thickness can be formed.

Next, a second organic thin film layer 9 having a function as a light-emitting layer is formed. The second organic thin film layer 9 can be formed in the same manner as the first organic thin film layer 7. That is, the ink containing the material for forming the red light-emitting layer 9, the ink containing the material for forming the green light-emitting layer 9, and the ink containing the ink for forming the blue light-emitting layer 9 are respectively supplied. The light-emitting layer 9 is formed by solidifying the ink to the region surrounded by the partition walls 3.

(Step of forming the second electrode)

In this step, the second electrode is formed on the organic thin film layer. In the present embodiment, the second electrode 10 is formed over the entire display region where the organic EL element 4 is provided. In other words, the second electrode 10 is formed not only on the second organic thin film layer 9 but also on the partition wall 3, and is formed continuously covering a plurality of organic EL elements. By forming the second electrode in this way, the setting has The second electrode 10 which functions as a common electrode of all of the organic EL elements 4.

In the above description, a display device in which a square-shaped partition wall is provided is described. However, as described above, a long partition wall may be provided on the support substrate. Fig. 6 is a plan view schematically showing a part of the display device of the embodiment. In the figure, the area where the hatching is applied corresponds to the partition wall 3. Fig. 7 is a view showing the sectional shape of the display device which cuts the display device in a plane perpendicular to the column direction X. Further, the cross-sectional shape of the display device of the display device is cut in a plane perpendicular to the row direction Y, which is the same as in the first drawing. The display device of the present embodiment is almost the same as the configuration of the display device of the above-described embodiment. Therefore, in the following description, only the differences will be described, and the corresponding parts will be referred to with the same reference numerals and the description will not be repeated.

When a long-shaped partition wall is provided, the partition wall is constituted by, for example, a plurality of partition wall members extending in the row direction Y. The partition member in this region is disposed at a predetermined interval in the column direction X. In the form in which the elongated partition walls are provided, the elongated recesses are defined by the elongated partition walls and the support substrate.

When the elongated partition walls are provided, the organic EL elements 4 are arranged in the respective recesses extending in the row direction Y, and are arranged in the row direction Y at predetermined intervals.

The first electrodes 6 are arranged in a matrix shape in the same manner as in the above embodiment. The partition wall 3 is formed such that the end portion 3a covers one end portion of the first electrode 6 in the column direction X and the other end portion (refer to Fig. 1). As shown in Fig. 7, in the present embodiment, the first electrode 6 is on the line. The end in the direction Y is not covered by the partition wall.

In the present embodiment, the first organic thin film layer 7 and the second organic thin film layer 9 are formed so as to extend over the respective concave portions extending in the row direction Y, and are connected to cover a plurality of organic EL elements. form.

<Configuration of Organic EL Element>

The configuration of the organic EL element will be described in more detail below. The organic EL element has at least one light-emitting layer as an organic thin film layer. As described above, the organic EL element may have, for example, a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, an electron injecting layer, or the like as an organic thin film layer.

An example of the layer configuration that the organic EL device of the present embodiment can take is as follows.

a) anode / luminescent layer / cathode

b) anode / hole injection layer / luminescent layer / cathode

c) anode / hole injection layer / luminescent layer / electron injection layer / cathode

d) anode/hole injection layer/light-emitting layer/electron transport layer/electron injection layer/cathode

e) anode/hole injection layer/hole transport layer/light-emitting layer/cathode

f) anode/hole injection layer/hole transport layer/light-emitting layer/electron injection layer/cathode

g) anode/hole injection layer/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode

h) anode / luminescent layer / electron injection layer / cathode

i) anode / luminescent layer / electron transport layer / electron injection layer / cathode

(Here, the symbol "/" indicates that each layer held by the symbol "/" is adjacent to each other and is layered. The same applies hereinafter)

The organic EL device of the present embodiment may have two or more light-emitting layers. In any one of the layer configurations of the above-mentioned a) to i), when the layered body sandwiched between the anode and the cathode is referred to as "structural unit A", it is constituted as an organic EL element having two light-emitting layers. As an example, the layer constitution shown by the following j) is mentioned. The layer composition of two (structural unit A) may be the same or different from each other.

j) Anode / (structural unit A) / charge generation layer / (structural unit A) / cathode

Here, the charge generating layer is a layer that generates holes and electrons by applying an electric field.

The charge generating layer may, for example, be a film composed of vanadium oxide, indium tin oxide (ITO), indium zinc oxide (Indium Zinc Oxide: abbreviated as IZO), or molybdenum oxide.

In addition, when the "(structural unit A) / charge generation layer" is the "structural unit B", the composition of the organic EL element having three or more light-emitting layers is as shown in the following k). .

k) anode / (structural unit B) x / (structural unit A) / cathode

The symbol "x" indicates an integer of 2 or more, and (structural unit B) x indicates a laminated body in which the structural unit B is laminated by the x-segment. Further, a plurality of layers (structural unit B) may be identical or different from each other.

In addition, the charge generation layer may not be provided, and the layer may be directly laminated. A plurality of light-emitting layers constitute an organic EL element.

<Support substrate>

The support substrate is preferably one which does not cause a chemical change in the step of manufacturing the organic EL element. Examples of the material of the support substrate include glass, plastic, polymer film, and ruthenium substrate, and the like.

<anode>

The anode is an electrode having light permeability. As the electrode, a metal oxide or a metal monolayer film and a laminated film having high electrical conductivity can be used. Specific examples thereof include metal oxides such as indium oxide, zinc oxide, tin oxide, ITO (Indium Tin Oxide), and indium zinc oxide (Indium Zinc Oxide: IZO); gold, platinum, and the like. A metal such as silver, copper, aluminum or magnesium, and a single layer film and a laminated film comprising at least one or more alloys of the above metals. Further, examples of the composition of the laminated film include ITO\Ag\ITO, IZO\Ag\IZO, ITO\APC (AgPdCu alloy)\ITO, IZO\APC (AgPdCu alloy)\IZO, ITO\AgCu alloy\ITO, IZO\AgCu alloy\IZO, ITO\AgMg alloy\ITO, IZO\AgMg alloy\IZO, etc. Examples of the method for producing the anode include a vacuum deposition method, a sputtering method, an ion deposition method, and a plating method.

<cathode>

The cathode material is preferably a material having a small work function and easy electron injection into the light-emitting layer and high electrical conductivity. Further, in the organic EL device having the light-receiving light from the anode side, since the cathode emits light emitted from the light-emitting layer to the anode side, the cathode material is preferably a material having a high reflectance with respect to visible light. Examples of the cathode material include metals and alloys. Graphite and graphite intercalation compounds. Examples of the metal include an alkali metal, an alkaline earth metal, a transition metal, and a Group 13 metal of the periodic table. Specific examples thereof include lithium, sodium, potassium, rubidium, cesium, cesium, magnesium, calcium, strontium, barium, aluminum, strontium, Vanadium, zinc, antimony, indium, antimony, bismuth, antimony, antimony, antimony, etc. The alloy may, for example, be an alloy of two or more of the above metals; and one or more of the above metals may be selected from the group consisting of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, and tin. Specific examples of the alloy of one or more kinds of metals, such as a magnesium-silver alloy, a magnesium-indium alloy, a magnesium-aluminum alloy, an indium-silver alloy, a lithium-aluminum alloy, a lithium-magnesium alloy, and the like are exemplified. Lithium-indium alloy, calcium-aluminum alloy, and the like. Further, the cathode may be a transparent electrode, and examples of the material include conductive metal oxides such as indium oxide, zinc oxide, tin oxide, ITO, and IZO; polyaniline or a derivative thereof, polythiophene or a derivative thereof, and the like. Conductive organic matter. Further, the cathode may have a laminated structure in which two or more layers are laminated. Further, an electron injecting layer can also be used as the cathode.

Examples of the method for producing the cathode include a vacuum deposition method, an ion deposition method, and the like.

The film thickness of the anode or the cathode can be appropriately set in consideration of desired characteristics or easiness of the film formation step, and the like, for example, is 10 nm to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500 nm.

<hole injection layer>

Examples of the hole injecting material constituting the hole injection layer include oxides such as vanadium oxide, molybdenum oxide, cerium oxide, and aluminum oxide; phenylamine compounds; starburst amine compounds; Compound; amorphous carbon; polyaniline; and polythiophene derivatives.

The film formation method of the hole injection layer may, for example, be a film formation from a solution containing a hole injection material. For example, a solution containing a hole injecting material can be applied to a film by a predetermined coating method, and then the solvent is volatilized by drying and sintering to be solidified, thereby forming a hole injection layer. Whether the organic material is a polymer material or a soluble low molecular material, the production method of the present invention can be applied as long as it can be formed by a coating method.

The film thickness of the hole injection layer can be appropriately set in consideration of desired characteristics or easiness of the film formation step, and the like, for example, is 1 nm to 1 μm, preferably 2 nm to 500 nm, and more preferably 5 nm to 200 nm.

<hole transport layer>

Examples of the hole transporting material constituting the hole transporting layer include polyvinylcarbazole or a derivative thereof, polydecane or a derivative thereof, a polyoxyalkylene having a side chain or a main chain having an aromatic amine, or a derivative thereof. Pyrazoline derivative, arylamine derivative, diphenylethylene derivative, triphenyldiamine derivative, polyaniline or its derivative, polythiophene or its derivative, polyarylamine or its derivative, polypyrrole Or a derivative thereof, poly(p-phenylene vinyl) or a derivative thereof, or poly(2,5-thiopheneethylene) or a derivative thereof.

Among these, the hole transporting material is preferably polyvinyl carbazole or a derivative thereof, polydecane or a derivative thereof, a polyoxyalkylene derivative having an aromatic amine compound group in a side chain or a main chain, polyaniline or a polymer thereof, a polythiophene or a derivative thereof, a polyarylamine or a derivative thereof, a poly(p-styrene) or a derivative thereof, or a polymer such as poly(2,5-thiopheneethylene) or a derivative thereof The hole transporting material is more preferably polyvinyl carbazole or a derivative thereof, polydecane or a derivative thereof, or a polyoxyalkylene derivative having an aromatic amine in a side chain or a main chain. Low molecular When the material is transported by the hole, it is preferably dispersed in a polymer binder for use.

The film formation method of the hole transport layer is not particularly limited. When a low molecular hole transport material is used, a film mixture is formed from a mixed solution containing a polymer binder and a hole transport material, and the polymer hole transport material may be formed from a solution containing a hole transport material. Membrane.

The solvent to be used for the film formation from the solution is not particularly limited as long as it can dissolve the hole transporting material, and examples thereof include a chlorine solvent such as chloroform, dichloromethane or dichloroethane. An ether solvent such as tetrahydrofuran; an aromatic hydrocarbon solvent such as toluene or xylene; a ketone solvent such as acetone or methyl ethyl ketone; and an ester system such as ethyl acetate, butyl acetate or ethyl cyproterone acetate. Solvent; and mixtures of these, and the like.

As a film formation method by a solution, the coating method similar to the film formation method of the said cavity injection layer is mentioned. From the viewpoint of long life, it is preferred to form a film in the same environment as the above-described adjacent layer forming step.

The polymer binder to be mixed is preferably one which does not extremely impede charge transport. Further, a polymer binder which is weak in absorption of visible light can be suitably used. Examples of the polymer binder include polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyoxyalkylene, and the like.

The film thickness of the hole transport layer can be appropriately set in consideration of the required characteristics and the ease of the film forming step, and is, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, and more preferably 5 nm to 200 nm.

<Light Emitting Layer>

The luminescent layer is usually composed of organic substances containing fluorescing and/or phosphorescence. The luminescent layer may further contain a dopant that assists the organic material. The dopant is added, for example, to increase the luminous efficiency or to change the wavelength of the emission. The organic substance constituting the light-emitting layer may be a low molecular compound or a high molecular compound. When the light emitting layer is formed by a coating method, the light emitting layer preferably contains a polymer compound. The polystyrene-equivalent number average molecular weight of the polymer compound constituting the light-emitting layer may be, for example, about 10 ³ to 10 ⁸ . Examples of the light-emitting material constituting the light-emitting layer include the following pigment materials, metal complex materials, polymer materials, and dopant materials.

(pigmented material)

Examples of the pigment-based material include a cyclopentylamine derivative, a tetraphenylbutadiene derivative compound, and a triphenylamine derivative. Diazole derivatives, pyrazoloquinoline derivatives, stilbene benzene derivatives, stilbene extended aryl derivatives, pyrrole derivatives, thiophene ring compounds, pyridine ring compounds, perinone derivatives, hydrazine derivatives Substance, oligothiophene derivative, An oxadiazole dimer, a pyrazoline dimer, a quinacridone derivative, and a coumarin derivative.

(metal complex material)

The metal complex-based material may, for example, be a central metal having a rare earth metal (for example, Tb, Eu, Dy, Al), Zn, Be, Ir, Pt, or the like, and A metal complex of a ligand such as an oxadiazole, a thiadiazole, a phenylpyridine, a phenylbenzimidazole or a quinoline structure. Examples of the metal complex include a metal complex having a light emission from a triplet state, such as an indium complex or a platinum complex, an aluminum quinoline complex, and a quinolinol complex. Benzo An azole zinc complex, a benzothiazole zinc complex, an azomethyl zinc complex, a porphyrin complex, a phenanthroline complex, and the like.

(polymer material)

Examples of the polymer material include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polydecane derivatives, polyacetylene derivatives, polyfluorene derivatives, and polyvinylcarbazole derivatives. A material or a material obtained by polymerizing the above-mentioned pigment-based material or metal-based compound material.

The thickness of the light-emitting layer is usually about 2 nm to 200 nm.

<Electronic transport layer>

As the electron transporting material constituting the electron transporting layer, generally known materials can be used, and for example, An oxadiazole derivative, quinodimethane or a derivative thereof, benzoquinone or a derivative thereof, naphthoquinone or a derivative thereof, hydrazine or a derivative thereof, tetracyanoquinodimethane or a derivative thereof, anthrone or its a derivative, a diphenyldicyanoethylene or a derivative thereof, a diphenylguanidine or a derivative thereof, a metal complex of 8-hydroxyquinoline or a derivative thereof, a polyquinoline or a derivative thereof, a polyquinoxaline Or a derivative thereof, polyfluorene or a derivative thereof, and the like.

The film thickness of the electron transport layer can be appropriately set in consideration of desired characteristics or easiness of the film formation step, and the like, for example, is 1 nm to 1 μm, preferably 2 nm to 500 nm, and more preferably 5 nm to 200 nm.

<electron injection layer>

The electron injecting material constituting the electron injecting layer can be appropriately selected depending on the type of the light emitting layer, and examples of the electron injecting layer material include an alkali metal; an alkaline earth metal; and an alloy containing at least one of an alkali metal and an alkaline earth metal; An oxide, a halide or a carbonate of an alkali or alkaline earth metal; And a mixture of the foregoing substances and the like. Examples of the alkali metal and its oxides, halides, and carbonates include lithium, sodium, potassium, rubidium, cesium, lithium oxide, lithium fluoride, sodium oxide, sodium fluoride, potassium oxide, and potassium fluoride. Antimony oxide, antimony fluoride, antimony oxide, antimony fluoride, lithium carbonate, and the like. Further, examples of the alkaline earth metal and its oxides, halides and carbonates include magnesium, calcium, barium, strontium, magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride, barium oxide, and barium fluoride. , cerium oxide, cerium fluoride, magnesium carbonate, and the like. The electron injecting layer may have a laminated structure in which two or more layers are laminated, and examples thereof include LiF/Ca and the like.

The film thickness of the electron injecting layer is preferably from 1 nm to 1 μm.

Examples of the method for forming each of the organic thin film layers include a coating method such as a nozzle printing method, an inkjet printing method, a relief printing method, and a gravure printing method, and a vacuum vapor deposition method.

Further, in the coating method, an ink containing an organic EL material serving as each organic thin film layer is applied to a film, and the organic thin film layer is formed by curing. Examples of the solvent of the ink used in the coating method include a chlorine-based solvent such as chloroform, dichloromethane or dichloroethane; an ether solvent such as tetrahydrofuran; and an aromatic hydrocarbon such as toluene or xylene. Solvent; ketone solvent such as acetone or methyl ethyl ketone; ester solvent such as ethyl acetate, butyl acetate or ethyl cellosolve acetate; and water.

When a color organic EL device is produced, for example, the film thickness of the hole injection layer is changed for each color, and the effect of the micro-cavity which is optimal for each color can be obtained.

Fig. 9 is a view showing the use of a green luminescent material which can obtain the photoexcitation light (PL) spectrum (peak wavelength 517 nm) shown in Fig. 8 In the organic EL device of the optical layer, the EL spectrum when the film thickness of the hole injection layer was changed was simulated. In the simulation, the configuration of the organic EL element is referred to as "anode/hole injection layer/hole transport layer/light-emitting layer/cathode", and the structure of the anode is ITO\APC\ITO=7 nm\18 nm\110 nm, cathode The structure was set to NaF\Al=2 nm\1500 nm, the film thickness of the light-emitting layer was set to 100 nm, and the film thickness of the hole transport layer was set to 20 nm, and the EL spectrum of light emitted in a direction perpendicular to the support substrate 2 was calculated.

For example, when the film thickness of the hole injection layer is 40 nm, the peak wavelength is 526 nm, and the CIE chromaticity coordinates x = 0.216 and y = 0.731. When the film thickness of the hole injection layer was 50 nm, the peak wavelength was 542 nm, and the CIE chromaticity coordinates x=0.273 and y=0.697. These two illuminating colors can be clearly recognized as different colors.

Thus, even if the film thickness of the hole transport layer is changed by only 10 nm, the spectrum of the original luminescent material itself is greatly changed. This is due to the micro-recave effect, and the wavelength region of the light that is selectively forced under a certain viewing angle is changed due to the difference in film thickness of the hole transport layer. Of course, in a display device comprising an organic EL element having a film thickness unevenness in the hole transport layer, the unevenness of the film thickness causes a stain on the display screen, and the product yield is lowered.

According to the production method of the present invention, a micropore structure having a film thickness of a suitable hole transporting layer can be formed, and an organic EL element having a desired chromaticity can be produced.

Example

First, a TFT substrate is prepared, and the TFT substrate is formed with: The first electrode 6 composed of an ITO layer having a thickness of 7 nm, an APC layer having a thickness of 18 nm, and an ITO layer having a thickness of 110 nm was formed in this order from the side of the support substrate (see FIG. 3A). In the third drawing, the boundary between the ITO layer and the APC layer is omitted, and the entire laminated film is shown as the first electrode 6.

Then, the liquid-repellent 2 (Daikin's liquid-repellent OPTOACE (registered trademark) HP series) was mixed in a negative photosensitive resin composition solution (ZPN 2464, manufactured by Zeon Japan Co., Ltd.) to prepare a photosensitive agent containing a liquid-repellent agent. Resin composition. The solid content concentration ratio of the liquid-repellent agent to the total solid content of the photosensitive resin composition after the liquid-repellent-removing agent is removed ((liquid-repellent agent/total solid content of the photosensitive resin composition after deducting the liquid-repellent agent) × 100} Set to 0.2% by weight. Then, a photosensitive resin composition containing a liquid-repellent agent was applied onto the surface of the prepared TFT substrate by a spin coater, followed by heating at 110 ° C for 90 seconds on a hot plate, thereby performing a prebaking treatment. By this prebaking treatment, the solvent of the photosensitive resin composition is evaporated to form a film for forming a partition wall (refer to FIG. 3B).

Next, using a proximity exposure machine, the film for forming a partition wall was exposed through a predetermined mask at an exposure amount of 100 mJ/cm ² (refer to FIG. 3C). Then, after heating at 110 ° C for 60 seconds, post-exposure baking (PEB) was carried out, and development was carried out for 100 seconds using a developing solution (SD-1 (TMAH 2.38 wt%) manufactured by Tokuyama Co., Ltd.).

Subsequently, it was heated at 230 ° C for 30 minutes as a post-baking, and the resin was hardened to form a tapered partition wall (refer to FIG. 4A). The film thickness of the partition wall was set to 0.6 μm. The contact angle between the top surface of the partition wall and pure water is 75°, and the contact angle of the top surface of the partition wall with anisole is 39°. In addition, the surface of the first electrode and pure water The contact angle is 25°. Further, when the film thickness formed as the partition wall is 1.0 μm, a partition wall having a reverse tapered shape is formed. In the present embodiment, a tapered partition wall is used, but a reverse tapered partition wall may be used.

Next, a hole injection layer as a first organic thin film layer is formed. The developing solution (SD-1 (TMAH 2.38 wt%) manufactured by Tokuyama Co., Ltd.), which is the same as the developer of the partition wall, was diluted to 0.5 wt% with pure water, and the surface of the substrate was washed. By this washing, the contact angle of the surface of the first electrode with pure water is lowered to 5 or less, and sufficient wettability to the surface of the first electrode (ITO film) can be imparted. At this time, the contact angle of the top surface of the partition wall with anisole was 35°. Then, using an inkjet apparatus (Litlex 142P manufactured by ULVAC Co., Ltd.), an ink (poly(ethylene dioxythiophene) (PEDOT) / polystyrene sulfonic acid (PPS) aqueous dispersion having a solid concentration of 1.5% by weight (AI4083 manufactured by Bayer Co., Ltd.) )) is applied to each recess (refer to Figure 4C). Since the partition wall 3 exhibits liquid repellency, it does not overflow to the adjacent recess, and the ink can be accommodated in the region (recess 5) surrounded by the partition wall 3. The ink is not partially removed on the first electrode and can be uniformly held on the first electrode. A hole injection layer having a uniform film thickness was formed by sintering the substrate at 200 ° C (refer to FIG. 5A).

Next, a hole transport layer is formed as the second organic thin film layer 9. The composition ratio (weight) of the polymer hole transporting compound to cyclohexylbenzene and 4-methyl-anisole (alias 4-methoxy-toluene) was 8:2 in a ratio of 0.28% by weight. In the mixed solvent, an ink for forming a hole transport layer was obtained. The ink for forming a hole transport layer was applied to a predetermined concave portion by using an inkjet device (Litlex 142P manufactured by ULVAC Co., Ltd.) to obtain a film thickness. 20 nm coating film. The substrate provided with the coating film was heated at 190 ° C for 60 minutes in a nitrogen atmosphere to insolubilize the coating film, and then naturally cooled to room temperature to obtain a hole transport layer (the hole transport layer is omitted in FIG. 5) .

Then three kinds of light-emitting layers are formed. First, the red light-emitting polymer light-emitting material 1 was mixed with an organic solvent so that the concentration became 0.8% by weight to prepare a red ink. Similarly, the green light-emitting material 2 was mixed with an organic solvent so that the concentration became 0.8% by weight to prepare a green ink. The blue light-emitting polymer 2 was mixed with an organic solvent to have a concentration of 0.8% by weight to prepare a blue ink. Each of the red, green, and blue inks was applied to a predetermined concave portion by using an inkjet device (Litlex 142P manufactured by ULVAC Co., Ltd.). Since the ink is separated by the top surface of the partition wall of the region having a large contact angle, it is prevented from being transmitted to the top surface and overflowing to the adjacent region, and the ink is accommodated in the concave portion. A light-emitting layer having a uniform film thickness was formed by sintering the substrate at 130 ° C (refer to FIG. 5C).

Next, a second electrode (cathode) was formed by sequentially depositing a NaF layer (2 nm), a Mg layer (2 nm), an Al layer (1500 nm), and an Ag layer (100 nm) by a vacuum deposition method. Then, the package substrate was bonded and the organic EL element was packaged to fabricate a display device.

The organic thin film layer of each organic EL device is formed by the film thickness shown in the following Table 1 depending on the type of each organic EL device.

The EL spectrum of each of the organic EL elements produced in the above manner is shown in Fig. 10, Fig. 11, and Fig. 12 together with the photoexcitation light (PL) spectrum of the luminescent material. Fig. 10 shows an EL spectrum of a red organic EL element and a PL spectrum of a red luminescent material, Fig. 11 shows an EL spectrum of a green organic EL element and a PL spectrum of a green luminescent material, and Fig. 12 shows an EL spectrum of a blue organic EL element And the PL spectrum of the blue luminescent material. Further, the PL spectrum of each luminescent material can be obtained by measuring the PL spectrum of a sample in which only the luminescent layer is formed on the glass substrate. In the EL spectrum, it was confirmed that the PL spectrum of the luminescent material was sharper due to the micro-cavity effect, and the peak wavelength was shifted.

The luminescent properties of the obtained organic EL device are shown in Table 2 below. As shown in the second table below, it is confirmed that the desired chromaticity coordinate value can be obtained.

1‧‧‧ display device

2‧‧‧Support substrate

3‧‧‧ next door

End of the next door to the 3a‧‧

4‧‧‧Organic EL components

5‧‧‧ recess

6‧‧‧1st electrode

7‧‧‧1st organic film layer (hole injection layer)

9‧‧‧2nd organic film layer (light-emitting layer)

10‧‧‧2nd electrode

Claims (3)

A manufacturing method of a display device, comprising: a support substrate, a partition wall dividing a predetermined separation area on the support substrate, and a plurality of organic electric excitations respectively disposed on the separation area partitioned by the partition wall of the partition A method of manufacturing a display device including a first electrode, an organic thin film layer, and a second electrode in order from the support substrate side, wherein the organic light-emitting device includes a step of preparing a support substrate, and a top portion of the support substrate Provided is a partition wall formed by patterning a photosensitive resin composition containing a liquid repellent by a lithography technique, and a first electrode; and containing at least one of oxalic acid, phosphoric acid, acetic acid, nitric acid, and hydrochloric acid a solution of the photosensitive resin composition; a step of washing the surface of the first electrode; a step of forming an organic thin film layer by a coating method on the first electrode; and a layer on the organic thin film layer The step of forming the second electrode. The method of manufacturing a display device according to claim 1, wherein the first electrode is indium tin oxide, and the solution is a mixed solution of phosphoric acid and acetic acid and nitric acid. The method for producing a display device according to claim 1, wherein the first electrode is indium zinc oxide, and the solution is a mixed solution of phosphoric acid and acetic acid and nitric acid or an aqueous oxalic acid solution.