JP2007157404A - Display device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device equipped with an organic luminescent element excellent in characteristics such as luminance or the like, wherein emitted light from adjacent organic luminescent elements can be prevented from being mutually mixed, and a highly reliable electronic apparatus. <P>SOLUTION: This display device 10 has a plurality of the organic luminescent elements (organic EL element) 1 equipped with a pair of electrodes (an anode 3 and a cathode 5), an organic semiconductor layer 4 provided between these electrodes while containing a luminescent layer, and a bank 31 provided so as to partition these organic luminescent elements 1. In this display device 10, the inner surface of the bank 31 is formed of a light reflecting surface having a function to reflect light from the organic luminescent elements 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device and an electronic apparatus.

An electroluminescence element (organic EL element) using an organic semiconductor material is expected to be used as a light-emitting element included in an inexpensive large-area full-color display device of solid-state light emission type, and many developments are performed (for example, Patent Document 1).
In general, an organic EL element is configured to have a light emitting layer (organic semiconductor layer) between a cathode and an anode, and when an electric field is applied between the cathode and the anode, electrons are injected into the light emitting layer from the cathode side, Holes are injected from the anode side.

Then, the injected electrons and holes are recombined in the light emitting layer, and the light emitting layer emits light by releasing the excitation energy when the energy level returns from the conduction band to the valence band as light energy.
For example, in Patent Document 2, as shown in FIG. 10, a pixel electrode 901, a light emitting layer 902, and a transparent counter electrode 903 are provided in this order on a substrate 900, and the opposite side of the substrate 900 (the counter electrode 903 side). Thus, an organic EL element (organic light emitting element) 910 having a top emission structure for extracting emitted lights l _{1 to} l ₈ from the light emitting layer 902 has been proposed.
Since the organic EL element 910 having a top emission structure can be provided with a switching element and wiring for controlling ON / OFF of energization between the electrodes on the substrate 900 side, the aperture ratio of the light emitting layer 902 is increased and the power consumption is reduced. Since it is possible to reduce the power consumption, etc., attention has been paid and various researches have been made for practical use.

Here, in the display device 920 including a plurality of such organic EL elements 910, the color filter substrate 911 including the color filter 912 is provided on the counter substrate 903 side, and the emitted lights l _{1 to} l ₈ are transmitted through the color filter 912. Thus, full-color image display is realized by changing the color tone (color modulation).
Here, in such a display device 920, emitted light l _{1 to} l ₈ from each organic EL element 910 is emitted in all directions, and adjacent organic EL elements like emitted light l ₂ and l ₄ are emitted. There is a problem in that color unevenness and contrast decrease occur due to a phenomenon in which emitted light from 910 is mixed (that is, a crosstalk phenomenon).

As a method for solving this problem, for example, there is a method in which the separation distance between the organic EL element 910 and the color filter substrate 911 is as small as possible and the black matrix 913 that partitions the color filters 912 is increased.
However, in this method, depending on the increase in the size of the black matrix 913, the size of each color filter 912, that is, the aperture ratio of each color filter (pixel) 912 is reduced. As a result, the characteristics (display characteristics) of the display device 920 are degraded.

JP-A-10-153967 Japanese Patent Laid-Open No. 2005-62480

  An object of the present invention is to provide a display device including an organic light-emitting element that is excellent in characteristics such as light emission luminance and a highly reliable electronic device while preventing light emitted from adjacent organic light-emitting elements from being mixed with each other. There is.

Such an object is achieved by the present invention described below.
A display device according to the present invention includes a plurality of organic light emitting elements including a pair of electrodes and an organic semiconductor layer including a light emitting layer provided between the electrodes,
A bank provided so as to partition each of the organic light emitting elements, and an inner surface of the bank is constituted by a light reflecting surface having a function of reflecting light from the organic light emitting elements.
Thereby, it can prevent that the emitted light of adjacent organic light emitting elements mutually mixes, and can be set as a display apparatus provided with the organic light emitting element excellent in characteristics, such as light-emitting luminance.

In the display device of the present invention, it is preferable that the bank has a portion whose width decreases toward the organic light emitting element.
Thereby, when manufacturing the display device, even when the alignment accuracy is low, the organic light emitting element can be partitioned relatively easily without bringing the bank into contact with the organic light emitting element.

In the display device according to the aspect of the invention, it is preferable that an angle formed between a surface of the bank opposite to the organic light emitting element and an inner surface of the bank is 60 ° or more and less than 90 °.
Thereby, when manufacturing the display device, even when the alignment accuracy is low, the organic light emitting element can be reliably partitioned without making the bank contact the organic light emitting element relatively easily.

In the display device of the present invention, the bank preferably has an inner surface reflectance of 60 to 99.8%.
Thereby, it can prevent or suppress that the light which injected into the bank is absorbed by the inner surface suitably.
In the display device of the present invention, the bank preferably has an inner surface roughness Ra (specified in JIS B 0601) of 100 nm or less.
Thereby, the inner surface of the bank has a particularly high reflectance.

In the display device according to the aspect of the invention, it is preferable that the electrode on the opposite side of the bank of the organic light emitting element has light reflectivity.
Thereby, the light emitted from the organic semiconductor layer can be reflected to the bank side without being absorbed (absorbed) on the electrode side opposite to the bank.
In the display device of the present invention, among the pair of electrodes included in the organic light emitting element, at least the bank side electrode is configured by a common electrode, and at least the inner surface of the bank is configured by a conductive material,
It is preferable that the electric conductivity of the common electrode is improved by bringing the bank into contact with the common electrode.
As a result, the light emitting device can be driven at a lower voltage.

In the display device according to the aspect of the invention, it is preferable that the bank and the common electrode are connected via an electrical connection portion.
In the display device of the present invention, it is preferable that the electrical conductivity of the connection portion is higher than the electrical conductivity of the bank.
Thereby, when applying a voltage between a pair of electrodes via this bank and a connection part, the electrical conductivity as the whole common electrode can be improved more.

In the display device according to the aspect of the invention, it is preferable that the conductive material is mainly composed of at least one of Al, Ni, Co, Ag, and an alloy containing these.
By configuring the bank as such a main material, the bank can be provided with excellent conductivity, and the inner surface can have excellent light reflectivity.
In the display device of the present invention, it is preferable that a switching element that switches ON / OFF of energization to the organic light emitting element is provided on the opposite side of the bank of the light emitting element.
Thereby, the organic light emitting element included in the display device has a top emission type structure.

In the display device of the present invention, each of the organic light emitting elements preferably emits white light.
In the display device of the present invention, a black matrix that includes an opening corresponding to each of the organic light emitting elements and prevents light from being transmitted from the organic light emitting elements is provided on the opposite side of each of the organic light emitting elements of the bank. It is preferable.
Thereby, it is possible to reliably prevent light from the organic light emitting element from being taken out from the region where the black matrix is provided to the side opposite to the organic light emitting element of the black matrix. Thereby, the contrast of the image or video displayed by the display device can be increased.

In the display device of the present invention, it is preferable that a dye layer is provided in each of the openings, and the color tone of light from each of the organic light emitting elements is converted when passing through the dye layer.
Thereby, when each organic light emitting element is configured to emit white light, full-color display of the display device becomes possible.
In the display device of the present invention, it is preferable that a space between the organic light emitting element and the black matrix is sealed, and the space is filled with an inert gas.
Thereby, it can prevent or suppress suitably that the organic-semiconductor layer etc. with which an organic light emitting element is equipped deteriorate and deteriorate.

In the display device according to the aspect of the invention, it is preferable that the banks are provided in a pattern substantially equal to the pattern of the black matrix.
As a result, it is possible to prevent occurrence of crosstalk phenomenon in which light from adjacent organic light emitting elements is mixed, and to surely prevent unevenness in an image.
In the display device according to the aspect of the invention, it is preferable that an opening area of the opening is larger than at least a plane area of an electrode having a smaller plane area among the pair of electrodes included in the organic light emitting element.
Thereby, the light from the organic EL element can pass through the opening and be taken out to the side opposite to the bank.

In the display device of the present invention, when the flat area of the electrode having the smaller flat area is A [μm ² ] and the opening area of the opening is B [μm ² ], B / A is 1.0 to 1.0. It is preferable to satisfy the relationship of 1.5.
Thereby, the light from the organic EL element can be reliably passed through the opening and taken out to the opposite side of the bank.

In the display device of the present invention, the opening has a quadrangular shape in plan view,
When the average height of the bank is C [μm] and the average width of the opening is D [μm], it is preferable that the relationship of D / C of 0.2 to 5 is satisfied.
Thereby, the direction of the light radiate | emitted on the opposite side to a bank can be closely approached with respect to the thickness direction of an organic light emitting element, preventing the enlargement of a display apparatus.
An electronic apparatus according to the present invention includes the display device according to the present invention.
Thereby, a highly reliable electronic device can be obtained.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a display device and an electronic apparatus of the invention will be described with reference to the accompanying drawings.
<Display device>
First, a preferred embodiment of the display device of the present invention will be described.

<< First Embodiment >>
First, a first embodiment of the display device of the present invention will be described.
1 and 2 are views showing a first embodiment of a display device according to the present invention. FIG. 1 is a longitudinal sectional view and FIG. 2 is a perspective view. FIG. 3 is a view (longitudinal sectional view) for explaining a manufacturing method of the display device shown in FIG. In the following description, the upper side in FIGS. 1 and 3 is referred to as “upper” and the lower side is referred to as “lower”.

A display device (organic electroluminescence (EL) display device) 10 of the present invention shown in FIG. 1 includes a TFT circuit substrate (counter substrate) 20 and a plurality of organic EL elements (organic light emitting devices) provided on the substrate 20. 1, a color filter substrate 9 provided facing the TFT circuit substrate 20, and a bank 31 provided between the TFT circuit substrate 20 and the color filter substrate 9.
The TFT circuit substrate 20 includes a substrate 21 and a circuit unit 22 formed on the substrate 21.

Hereinafter, the TFT circuit substrate 20 will be described.
The substrate 21 serves as a support for each part of the display device 10.
In addition, since the display device 10 of the present embodiment has a configuration for extracting light from the color filter substrate 9 side (top emission type), the substrate 21 is not particularly required to be transparent.
As such a substrate 21, various glass material substrates and various resin substrates are used, and those having relatively high hardness are preferably used.

Although the average thickness of the board | substrate 21 is not specifically limited, It is preferable that it is about 1-30 mm, and it is more preferable that it is about 5-20 mm.
The circuit unit 22 has a function of switching ON / OFF of energization in the anode 3 and the cathode 5 included in each organic EL element 1, and includes a base protective layer 23 formed on the substrate 21 and a base protective layer 23. A driving TFT (switching element) 24, a first interlayer insulating layer 25, and a second interlayer insulating layer 26.

The driving TFT 24 includes a semiconductor layer 241, a gate insulating layer 242 formed on the semiconductor layer 241, a gate electrode 243 formed on the gate insulating layer 242, a source electrode 244, and a drain electrode 245. ing.
An organic EL element (light emitting element) 1 including a pair of electrodes (anode 3 and cathode 5) and an organic semiconductor layer 4 including a light emitting layer provided between these electrodes on such a circuit portion 22, A plurality of driving TFTs 24 are provided correspondingly.

In this embodiment, the anode 3 of each organic EL element 1 constitutes an individual electrode (pixel electrode) and is electrically connected to the drain electrode 245 of each driving TFT 24 by a wiring (conductive portion) 27.
Further, the organic semiconductor layer 4 of each organic EL element 1 is integrally formed, and the cathode 5 is a common electrode.

Hereinafter, the organic EL element 1 will be described.
As shown in FIG. 1, the organic EL element 1 includes individual anodes 3, a common cathode 5, and a common organic semiconductor layer 4 between the anode 3 and the cathode 5.
The anode 3 is an electrode that injects holes into the organic semiconductor layer (a light emitting layer described later) 4.
The constituent material (anode material) of the anode 3 is not particularly limited as long as it has conductivity, but a material having a large work function and excellent conductivity is preferably used.
Examples of such an anode material include ITO (composite of indium oxide and zinc oxide), SnO ₂ , Sb-containing SnO ₂ , oxides such as Al-containing ZnO, Al, Ni, Co, Au, Pt, and Ag. Cu, alloys containing these, and the like can be used, and at least one of them can be used.

  The average thickness of the anode 3 is not particularly limited, but is preferably about 10 to 200 nm, and more preferably about 50 to 150 nm. If the thickness of the anode 3 is too thin, the function as the anode 3 may not be sufficiently exhibited. On the other hand, if the anode 3 is too thick, recombination of holes and electrons, which will be described later, occurs in the organic semiconductor layer 4. This cannot be performed, and characteristics such as the light emission efficiency of the organic EL element 1 may be deteriorated.

As the anode material, for example, a conductive resin material such as polythiophene or polypyrrole can be used.
Such an anode 3 preferably has light reflectivity. Thereby, the light emitted from the organic semiconductor layer 4 described later is not absorbed (absorbed) on the anode 3 (electrode opposite to the black matrix 7 described later of the organic EL element 1) side, and the cathode 5 (bank 31). The amount of light reflected to the side and passing through the color filter 6 can be increased. As a result, characteristics such as the light emission efficiency and light extraction efficiency of the organic EL element 1 are improved.

The anode 3 having such a configuration can be formed by forming at least the surface of the anode 3 with Al, Ni, Co, Ag, or an alloy containing these among the anode materials as described above.
On the other hand, the cathode 5 is an electrode for injecting electrons into the organic semiconductor layer 4.
As the constituent material (cathode material) of the cathode 5, a conductive material having translucency is selected because the display device 10 has a top emission structure in which light is extracted from the cathode 5 side.

As such a cathode material, indium tin oxide (ITO), fluorine-containing indium tin oxide (FITO), antimony tin oxide (ATO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), tin oxide (SnO ₂ ). ), Zinc oxide (ZnO), fluorine-containing tin oxide (FTO), fluorine-containing indium oxide (FIO), indium oxide (IO), and the like, and at least one of these is used. Can do.

  The average thickness of the cathode 5 is not particularly limited, but is preferably about 100 to 3000 nm, and more preferably about 500 to 2000 nm. If the thickness of the cathode 5 is too thin, the function as the cathode 5 may not be sufficiently exhibited. On the other hand, if the cathode 5 is too thick, the light transmittance may decrease depending on the type of the cathode material. The organic EL element 1 having a top emission type structure may not be suitable for practical use.

Such a cathode 5 has a light transmittance (visible light region) of preferably 60% or more, more preferably 80% or more. Thereby, light can be efficiently extracted from the cathode 5 side.
An organic semiconductor layer 4 is provided between the anode 3 and the cathode 5. In the present embodiment, the organic semiconductor layer 4 is a single layer composed of a light emitting layer.

  Here, when energization (voltage is applied) between the individual anode 3 and the common cathode 5, holes are injected from the anode 3 into the light emitting layer (organic semiconductor layer 4), and electrons are emitted from the cathode 5. Holes and electrons are recombined in the regions corresponding to the individually provided anodes 3 of the light emitting layer. Then, excitons (excitons) are generated in the region of the light emitting layer, and energy (fluorescence or phosphorescence) is emitted (emitted) when the excitons return to the ground state. That is, the organic semiconductor layer (light emitting layer) 4 emits light corresponding to the shape of each organic EL element 1 (anode 3).

As a constituent material (luminescent material) of the light emitting layer, for example, 1,3,5-tris [(3-phenyl-6-tri-fluoromethyl) quinoxalin-2-yl] benzene (TPQ1), 1,3,5 Benzene compounds such as tris [{3- (4-t-butylphenyl) -6-trisfluoromethyl} quinoxalin-2-yl] benzene (TPQ2), phthalocyanine, copper phthalocyanine (CuPc), iron phthalocyanine Low molecular weight compounds such as non-metallic or metal-free phthalocyanine compounds, tris (8-hydroxyquinolinolate) aluminum (Alq ₃ ), factory (2-phenylpyridine) iridium (Ir (ppy) ₃ ) Polymers such as oxadiazole polymers, triazole polymers, carbazole polymers The desired luminescent color can be obtained by combining one or more of these.
In addition, the light emitting layer may be a single layer composed of one or more of such light emitting materials, or may be a multilayer.

In the present embodiment, each organic EL element 1 is configured to emit white light, and the white light is transmitted through color filters (pigment layers) 6R, 6G, and 6B, which will be described later, to obtain red (R). The color tone is converted into green (G) and blue (B) light, and the display device 10 can display full color.
Here, as the organic semiconductor layer 4 that emits white light, for example, 1,1,4,4-tetraphenyl-1,3-butadiene (TPB) that emits blue light and red light (4-dicyanomethylene). Examples thereof include a combination of 2-methyl-6- (paradimethylaminostyryl) -4H-pyran (DCM) and Nile red and coumarin 6 that emits green light.

Although the average thickness of a light emitting layer is not specifically limited, It is preferable that it is about 10-150 nm, and it is more preferable that it is about 50-100 nm.
The organic semiconductor layer 4 may be a stacked body in which a plurality of layers including a light emitting layer are stacked in addition to a single layer body as shown in the present embodiment.
When the organic semiconductor layer 4 has such a configuration, for example, a hole transport layer having a function of transporting holes injected from the anode 3 to the light emitting layer is provided between the anode 3 and the light emitting layer. That's fine. Furthermore, a hole injection layer that improves the efficiency of hole injection from the anode 3 to the hole transport layer may be provided between the hole transport layer and the anode 3.
Further, an electron transport layer having a function of transporting electrons injected from the cathode 5 to the light emitting layer may be provided between the cathode 5 and the light emitting layer, for example. Furthermore, an electron injection layer that improves the injection efficiency of electrons from the cathode 5 to the electron transport layer may be provided between the electron transport layer and the cathode 5.

  As the constituent material (hole transport material) of this hole transport layer, for example, polyarylamine, fluorene-arylamine copolymer, fluorene-bithiophene copolymer, poly (N-vinylcarbazole), polyvinylpyrene, polyvinyl Anthracene, polythiophene, polyalkylthiophene, polyhexylthiophene, poly (p-phenylene vinylene), polytinylene vinylene, pyrene formaldehyde resin, ethyl carbazole formaldehyde resin or derivatives thereof, and the like, one or two of these A combination of the above can be used.

Moreover, the said compound can also be used as a mixture with another compound. As an example, the polythiophene-containing mixture includes poly (3,4-ethylenedioxythiophene / styrene sulfonic acid) (PEDOT / PSS).
The average thickness of such a hole transport layer is not particularly limited, but is preferably about 10 to 150 nm, and more preferably about 50 to 100 nm.

As a constituent material (hole injection material) of the hole injection layer, for example, copper phthalocyanine, 4,4 ′, 4 ″ -tris (N, N-phenyl-3-methylphenylamino) triphenylamine (m -MTDATA) and the like.
As a constituent material (electron transport material) of the electron transport layer, for example, 1,3,5-tris [(3-phenyl-6-tri-fluoromethyl) quinoxalin-2-yl] benzene (TPQ1), 1,3 , 5-tris [{3- (4-t-butylphenyl) -6-trisfluoromethyl} quinoxalin-2-yl] benzene (TPQ2), naphthalene compound, phenanthrene compound, chrysene Compounds, perylene compounds, anthracene compounds, pyrene compounds, acridine compounds, stilbene compounds, thiophene compounds such as BBOT, butadiene compounds, coumarin compounds, quinoline compounds, bistyryl compounds, distyryl pyrazines Pyrazine compounds, quinoxaline compounds, 2,5-diphenyl Benzoquinone compounds such as para-benzoquinone, naphthoquinone compounds, anthraquinone compounds, 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole (PBD) Oxadiazole compounds, triazole compounds such as 3,4,5-triphenyl-1,2,4-triazole, oxazole compounds, anthrone compounds, 1,3,8-trinitro-fluorenone (TNF) ) Fluorenone compounds, MBDQ diphenoquinone compounds, MBSQ stilbenequinone compounds, anthraquinodimethane compounds, thiopyrandioxide compounds, fluorenylidenemethane compounds, diphenyldicyanoethylene compounds Compounds, fluorene compounds, 8-hydroxy Quinoline aluminum (Alq _3), benzoxazole or benzothiazole include various metal complexes such as complexes having a ligand, can be used singly or in combination of two or more of them.

Although the average thickness of an electron carrying layer is not specifically limited, It is preferable that it is about 1-100 nm, and it is more preferable that it is about 20-50 nm.
Examples of the constituent material (electron injection material) of the electron injection layer include 8-hydroxyquinoline, oxadiazole, or derivatives thereof (for example, metal chelate oxinoid compounds containing 8-hydroxyquinoline). These can be used alone or in combination of two or more.

The color filter substrate 9 includes an upper substrate 8, color filters 6R, 6G, and 6B provided on the upper substrate 8, and a black matrix 7 that partitions the color filters 6R, 6G, and 6B. ing.
The upper substrate 8 functions as, for example, a protective layer that protects the organic EL element 1.
By providing the upper substrate 8 as described above, it is possible to more suitably prevent or reduce the contact of the organic EL element 1 with oxygen or moisture. Therefore, the reliability of the organic EL element 1 is improved, and the deterioration / deterioration is prevented. The effect of can be obtained more reliably.

In addition, since the organic EL device 10 of the present embodiment is configured to extract light from the color filter substrate 9, that is, the upper substrate 8 side (top emission type), the upper substrate 8 is substantially transparent (colorless and transparent, colored and transparent). , Translucent).
As such an upper substrate 8, a transparent one of various glass material substrates and various resin substrates is selected. For example, glass materials such as quartz glass and soda glass, polyethylene terephthalate, polyethylene naphthalate, polypropylene, cyclohexane are selected. A substrate composed mainly of a resin material such as olefin polymer, polyamide, polyethersulfone, polymethyl methacrylate, polycarbonate, polyarylate, or the like can be used.

The average thickness of the upper substrate 8 is not particularly limited, but is preferably about 0.1 to 30 mm, and more preferably about 0.1 to 10 mm.
Under the upper substrate 8, color filters (dye layers) 6R, 6G, and 6B are provided so as to correspond to the respective organic EL elements 1.
The plurality of color filters (pigment layers) 6R, 6G, 6B are composed of a red color filter 6R, a green color filter 6G, and a blue color filter 6B, and are arranged in a matrix as shown in FIG. The three color filters 6R, 6G, and 6B (three primary colors) provided constitute one set and constitute one pixel (pixel).

Here, the light (white light) emitted from the organic EL element 1 passes through the color filters (dye layers) 6R, 6G, and 6B and is extracted to the opposite side of the upper substrate 8 from the organic EL element 1. At this time, the color tone of each white light is converted to a color corresponding to each color filter 6R, 6G, 6B.
Hereinafter, the color filters 6R, 6G, and 6B may be collectively referred to as the color filter 6.
As such a color filter 6, for example, a transparent resin material or a resist material as described above can be used as a main material, and a colorant containing (added to) a coloring agent for coloring the main material can be used.

The resist material is water-soluble such as rosin-bichromate, polyvinyl alcohol (PVA) -bichromate, shellac-bichromate, casein-bichromate, PVA-diazo, acrylic photoresist, etc. Negative photoresists such as oil-soluble photoresists such as water-soluble photoresists, polyvinyl cinnamate, cyclized rubber-azide, polyvinylcinnamylidene acetate, polycinnamic acid β-vinyloxyethyl ester, and o-naphtho And positive photoresists such as oil-soluble photoresists such as quinonediazide.
As the colorant, for example, a dye or a pigment can be used. From the viewpoint of light resistance and weather resistance, it is preferable to use a fine pigment.

  Examples of red pigments used in the color filter 6R include perylene pigments, lake pigments, azo pigments, quinacridone pigments, anthraquinone pigments, anthracene pigments, and isoindoline pigments. As the green pigment, for example, a halogen polysubstituted phthalocyanine pigment, a halogen polysubstituted copper phthalocyanine pigment, a triphenylmethane basic dye, an isoindoline pigment, and an isoindolinone pigment are used for the color filter 6B. Examples of blue pigments include copper phthalocyanine pigments, indanthrene pigments, indophenol pigments, cyanine pigments, dioxazine pigments, and the like, and one or more of these are combined. Can be used .

The average thickness of the color filter 6 is not particularly limited, but is preferably about 0.5 to 10 μm, and more preferably about 0.5 to 3 μm.
A black matrix 7 is provided between the adjacent color filters 6. That is, adjacent color filters 6 are partitioned by the black matrix 7.

  The black matrix 7 has a function of blocking light transmission (light shielding). For this reason, the color filter substrate 9 is configured to include the black matrix 7 so that light from the organic EL element 1 is transmitted from the region where the black matrix 7 is provided to the organic EL of the upper substrate 8 (black matrix 7). It can be reliably prevented from being taken out (emitted) to the side opposite to the element 1. Thereby, the contrast of the image or video displayed by the display device 10 can be increased.

Such a black matrix 7 is made of, for example, Cr, Al, Ni, Zn, Ti and the like in addition to a transparent resin or resist layer in which carbon, titanium, or the like is dispersed.
The black matrix 7 is preferably composed of a smooth surface continuous with the color filter 6, and the average thickness thereof is preferably about 0.5 to 10 μm, similar to the color filter 6. More preferably, it is about ˜2 μm.
The present invention is characterized in that a bank 31 is provided between the color filter substrate 9 (black matrix 7) and the TFT circuit substrate 20 (organic EL element 1).

Hereinafter, this point (feature) will be described.
As shown in FIG. 1, in the present embodiment, the bank 31 has a pattern substantially equal to the pattern of the black matrix 7 and is provided so as to be in contact with both the black matrix 7 and the cathode 5. Thereby, a space 36 partitioned by the bank 31 is formed between the organic EL element 1 and the color filter 6.

Here, if the bank 31 is not provided, a crosstalk phenomenon occurs in which light from adjacent organic EL elements is mixed, resulting in color unevenness in an image displayed by the display device.
On the other hand, since the bank 31 is provided in the display device 10 of the present invention, the bank 31 functions as a light-shielding plate that partitions each organic EL element 1, so that the specific space 36 is adjacent to the adjacent space 36. Light leakage can be reliably prevented. As a result, in the display device 10 of the present invention, it is possible to prevent the occurrence of crosstalk phenomenon and the occurrence of unevenness in the image.

Further, by providing the bank 31, it is not necessary to bring the color filter 6 closer to the organic EL element 1 or to increase the formation area of the black matrix 7, so that the aperture ratio of the color filter 6 can be set large. It becomes possible.
Furthermore, in the display device 10 of the present invention, the inner surface of the bank 31 is configured as a reflective surface that can reflect the light from the organic EL element 1. Therefore, as shown in FIG. 1, among the light from the organic EL element 1, the light L ₁ that goes in the direction away from the corresponding color filter (opening) 6 is reflected by the inner surface (reflection surface) of the bank 31. Thus, it can be guided (guided) into the color filter 6. As a result, with the light L ₂ is transmitted through the color filter 6, it is possible to take out the organic EL element 1 of the upper substrate 8 on the opposite side. Thereby, the light emission luminance and light extraction efficiency of the organic EL element 1 can be improved, and the power consumption and the life of the display device 10 can be reduced.

In the present embodiment, as shown in FIG. 2, the banks 31 each have a frame shape (rectangular ring shape), and are provided integrally with adjacent banks 31.
The bank 31 only needs to be provided so as to surround the organic EL element 1, and the shape of the frame is, for example, a circle, an ellipse, a pentagon, a hexagon other than a quadrangular ring as in the present embodiment. Any shape such as a polygon such as a polygon may be used.

  In the present embodiment, the bank 31 has a portion whose width decreases toward the organic EL element 1 side. That is, the bank 31 has a portion where the cross-sectional area in the direction perpendicular to the thickness direction is small. Thereby, in the manufacturing method of the display device 10 to be described later, even when the alignment accuracy is low, the bank 31 surrounds the organic EL element 1 relatively easily without contacting the organic EL element 1. be able to.

Specifically, the angle formed by the surface of the bank 31 opposite to the organic EL element 1 and the inner surface of the bank 31 (angle θ shown in FIG. 1) is preferably 60 ° or more and less than 90 °. It is more preferably 70 ° or more and less than 90 °. By satisfying such a relationship, the effects as described above can be surely exhibited.
Moreover, the reflectance of the inner surface of the bank 31 is preferably about 60 to 99.8%, more preferably about 90 to 99.8%. Thus, the light L ₁ incident on the bank 31 can be suitably prevented or suppressed from being absorbed by the inner surface thereof. As a result, the light L ₁ is reflected by the inner surface of the bank 31 and is reliably transmitted through the color filter 6.

In order to obtain the bank 31 that satisfies such a relationship, it is preferable to set the surface roughness Ra of the inner surface as small as possible.
Specifically, the bank 31 has a slightly different surface roughness Ra (as defined in JIS B 0601) of 100 nm or less, preferably about 80 to 30 nm, although it varies slightly depending on the type of constituent material. More preferred. Thereby, the inner surface of the bank 31 has a particularly high reflectance.

In the present embodiment, the area (opening area) of the color filter (opening) 6 is larger than the anode 3 having a smaller area among the anode 3 and the cathode 5 (a pair of electrodes included in the organic EL element 1). It has become. Thereby, the light from the organic EL element 1 can be reliably extracted to the upper side of the upper substrate 8 (the side opposite to the bank 31) without being reflected in the space 36.
Specifically, when the plane area of the anode 3 (the plane area of the smaller plane area) is A [μm ² ] and the area (opening area) of the color filter 6 is B [μm ² ], B / A Preferably satisfies the relationship of 1.0 to 1.5, and more preferably satisfies the relationship of 1.0 to 1.2. Thereby, the effects as described above can be more remarkably exhibited.
The average height of the bank 31 is not particularly limited, but is preferably about 1 to 35 μm, and more preferably about 5 to 15 μm. Thereby, it is possible to reliably extract the light from the organic EL element 1 to the upper side of the upper substrate 8 while preventing an increase in the size of the display device 10.

  When the color filter 6 has a quadrangular shape in plan view as in the present embodiment, the average height of the bank 31 is C [μm], and the average width of the color filter (opening) 6 is D. When it is [μm], it is preferable to satisfy the relationship of D / C of 0.2 to 5, and it is more preferable to satisfy the relationship of 0.33 to 3. By satisfying such a relationship, the direction of light emitted to the upper side of the upper substrate 8 can be made parallel to the thickness direction of the organic EL element 1 while preventing an increase in the size of the display device 10. .

Furthermore, a space 36 between the organic EL element 1 and the black matrix 7 is sealed, and this space 36 is preferably filled with an inert gas such as nitrogen, helium and argon. Thereby, for example, it is possible to suitably prevent or suppress deterioration or deterioration of the organic semiconductor layer 4 or the like included in the organic EL element 1.
Here, the bank 31 may be made of any one of a conductive material, a semiconductor material, and an insulating material, but is particularly preferably made of a conductive material.

As described above, in the present embodiment, the cathode 5 on the color filter substrate 9 (black matrix 7) side of the pair of electrodes is configured as a common electrode, and the bank 31 is in contact with the cathode (common electrode) 5. Provided. As a result, the resistance value of the cathode 5 as a whole can be reduced (improvement of electrical conductivity), and the light emitting device 10 can be driven at a lower voltage.
Such a configuration is particularly effective when the cathode 5 is made of a conductive material having a relatively large resistance value, such as ITO described above.

Examples of such a conductive material include various metal materials and conductive resin materials. Among these, at least one of Al, Ni, Co, Ag, and alloys containing these is mainly used. What is made into a component is preferable. By configuring the bank 31 as the main material, it is possible to impart excellent conductivity to the bank 31 and to improve the light reflectivity of the inner surface thereof.
Note that the vicinity of the inner surface of the bank 31 may be selectively made of a conductive material, particularly the metal material. With this configuration, the same effect as described above can be obtained.

  As described above, by giving the bank 31 the function of reducing the resistance value of the entire cathode 5, the auxiliary cathode having such a function is formed on the second correlated insulating layer 26 exposed between the anodes 3. Since it does not need to be formed, the organic semiconductor layer 4 is integrally formed in one step without using a mask, as shown in a method for manufacturing the display device 10 (step [2-B]) described later. be able to. As a result, the number of steps for forming the organic semiconductor layer 4 can be reduced.

In the present embodiment, the case where an image obtained by transmitting light from the organic EL element 1 to the color filters 6R, 6G, and 6B is displayed in full color is described. However, the present invention is not limited to such a case. When the color filters 6R, 6G, and 6B are omitted and light is extracted from the opening corresponding to the organic EL element 1 without changing the color tone of the light, that is, an image or video displayed by the display device is displayed. The present invention can also be applied when displaying a single color (monocolor).
In the present embodiment, the bank 31 is described as having a pattern that is substantially the same as the pattern of the black matrix 7. However, the present invention is not limited to such a case, and the same color filter among the adjacent color filters 6 ( For example, the formation of the bank may be omitted at a position corresponding to between the color filters 6B).

Such a display device 10 of the present embodiment can be manufactured by, for example, the following manufacturing method.
[1] First, the TFT circuit substrate 20 is prepared.
[1-A] First, a substrate 21 is prepared, and an average thickness of about 200 to 500 nm is formed on the substrate 21 by, for example, plasma CVD using TEOS (tetraethoxysilane), oxygen gas, or the like as a source gas. A base protective layer 23 composed of silicon oxide as a main material is formed.

[1-B] Next, the driving TFT 24 is formed on the base protective layer 23.
[1-Ba] First, amorphous silicon having an average thickness of about 30 to 70 nm is mainly formed on the base protective layer 23 by the plasma CVD method or the like with the substrate 21 heated to about 350 ° C. A semiconductor film is formed.
[1-Bb] Next, the semiconductor film is crystallized by laser annealing, solid phase growth, or the like to change the amorphous silicon into polysilicon.
Here, in the laser annealing method, for example, a line beam with a beam length of 400 mm is used with an excimer laser, and the output intensity is set to about 200 mJ / cm ² , for example. As for the line beam, the line beam is scanned such that a portion corresponding to 90% of the peak value of the laser intensity in the short dimension direction overlaps each region.

[1-Bc] Next, the semiconductor film is patterned to form islands, and for example, a plasma CVD method using TEOS (tetraethoxysilane) or oxygen gas as a source gas so as to cover each island-shaped semiconductor film 241. Thus, a gate insulating layer 242 composed mainly of silicon oxide or silicon nitride having an average thickness of about 60 to 150 nm is formed.
[1-Bd] Next, a conductive film composed mainly of a metal such as aluminum, tantalum, molybdenum, titanium, or tungsten is formed on the gate insulating layer 242 by, for example, sputtering, and then patterned. A gate electrode 243 is formed.
[1-Be] Next, in this state, high concentration phosphorus ions are implanted to form source / drain regions in a self-aligned manner with respect to the gate electrode 243. Note that a portion where no impurity is introduced becomes a channel region.

[1-C] Next, the source electrode 244 and the drain electrode 245 electrically connected to the driving TFT 24 are formed.
[1-Ca] First, the first interlayer insulating layer 25 is formed so as to cover the gate electrode 243, and then a contact hole is formed.
[1-Cb] Next, the source electrode 244 and the drain electrode 245 are formed in the contact hole.

[1-D] Next, a wiring (relay electrode) 27 that electrically connects the drain electrode 245 and the anode 3 is formed.
[1-Da] First, the second interlayer insulating layer 26 is formed on the first interlayer insulating layer 25, and then contact holes are formed.
[1-Db] Next, a wiring 27 is formed in the contact hole.
As described above, the TFT circuit substrate 20 is obtained.

[2] Next, the organic EL element 1 is formed on the TFT circuit substrate 20.
[2-A] First, the anode (pixel electrode) 3 is formed on the second interlayer insulating layer 26 provided in the TFT circuit substrate 20 so as to be in contact with the wiring 27.
The anode 3 is formed on the second interlayer insulating layer 26 by using, for example, the above-described constituent material of the anode 3 as a main material by a vapor deposition method such as a vacuum deposition method or a sputtering method. It can be obtained by patterning after forming the film.

[2-B] Next, the organic semiconductor layer (light emitting layer) 4 is integrally formed so as to cover each anode 3 and the second correlated insulating layer 26 exposed between each anode 3.
The organic semiconductor layer 4 may be formed by, for example, a vapor phase process using a sputtering method, a vacuum evaporation method, a CVD method, a spin coating method (pyrosol method), a casting method, a micro gravure coating method, a gravure coating method, or a bar coating method. It can be formed by a liquid phase process using a roll coating method, a wire bar coating method, a dip coating method, a spray coating method, a screen printing method, a flexographic printing method, an offset printing method, an inkjet printing method, or the like. Among these, the organic semiconductor layer 4 is formed by a liquid phase process in consideration of the physical stability and / or chemical characteristics such as the thermal stability of the constituent material of the organic semiconductor layer 4 and the solubility in a solvent. Is preferred.

Specifically, the liquid material for forming the organic semiconductor layer is exposed to a region where the organic semiconductor layer 4 is formed by using a liquid phase process, that is, each anode 3 and the second correlation exposed between each anode 3. After supplying on the insulating layer 26 and removing the solvent or dedispersing medium, if necessary, heat treatment is performed at about 150 ° C. for a short time.
Examples of the desolvent or dedispersion medium include a method of leaving in a reduced pressure atmosphere, a method of heat treatment (for example, about 50 to 60 ° C.), a method of a flow of an inert gas such as nitrogen gas, and the like. Furthermore, the residual solvent is removed by performing additional heat treatment (about 150 ° C. for a short time).
The liquid material to be used is prepared by dissolving or dispersing the light emitting material as described above in a solvent or a dispersion medium.

  Examples of the solvent or dispersion medium used for preparing the liquid material include various inorganic solvents such as nitric acid, sulfuric acid, ammonia, hydrogen peroxide, water, carbon disulfide, carbon tetrachloride, ethylene carbonate, and methyl ethyl ketone (MEK). , Acetone solvents, diethyl ketone, methyl isobutyl ketone (MIBK), methyl isopropyl ketone (MIPK), ketone solvents such as cyclohexanone, alcohol solvents such as methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol (DEG), glycerin, diethyl ether , Diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (di) Rim), ether solvents such as diethylene glycol ethyl ether (carbitol), cellosolve solvents such as methyl cellosolve, ethyl cellosolve, phenyl cellosolve, aliphatic hydrocarbon solvents such as hexane, pentane, heptane, cyclohexane, toluene, xylene, Aromatic hydrocarbon solvents such as benzene, aromatic heterocyclic solvents such as pyridine, pyrazine, furan, pyrrole, thiophene, methylpyrrolidone, N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMA Amide solvents such as dichloromethane, chloroform, 1,2-dichloroethane, ester solvents such as ethyl acetate, methyl acetate, ethyl formate, sulfur compound solvents such as dimethyl sulfoxide (DMSO), sulfolane, etc. , Acetonitrile, propionitrile, nitrile solvents, formic acid such as acrylonitrile, acetic acid, trichloroacetic acid, various organic solvents such as an organic acid solvents such as trifluoroacetic acid, or mixed solvents containing them.

In the present embodiment, each organic EL element 1 emits white light, and the color filter 6 converts the color tone of the light, so that it is exposed between each anode 3 and each anode 3. The organic semiconductor layer 4 can be integrally formed on the entire surface of the second correlation insulating layer 26 to be formed.
Therefore, since it is not necessary to use a mask, a liquid phase process using a spin coating method (pyrosol method), a spray coating method, or the like is preferably used for these formations.
Further, in this embodiment, since it is not necessary to use a mask, for example, the mask forming process and the removing process can be omitted, and therefore, the manufacturing process of the display device 10 is simplified and the manufacturing cost is reduced. be able to.

[2-C] Next, the cathode 5 common to each anode 3 is formed on the organic semiconductor layer (light emitting layer) 4, that is, on the opposite side of the organic semiconductor layer 4 from the anode 3.
The cathode 5 can be formed by, for example, the gas phase process and the liquid phase process as described above.
These methods are selected in consideration of the physical stability and / or chemical characteristics such as the thermal stability of the constituent material of the cathode 5 and the solubility in a solvent.
In this embodiment, since the cathode 5 is formed on the entire surface of the organic semiconductor layer 4, it is not necessary to use a mask. For this formation, a vapor phase process using a sputtering method, a vacuum deposition method, or the like is used. Are preferably used.

[3] Next, the color filter substrate 9 provided with the bank 31 is prepared.
[3-A] First, the upper substrate 8 is prepared, and the color filter 6 is formed on the upper substrate 8 as shown in FIG.
[3-Aa] First, a resist layer having an opening in a region where the color filter 6 is to be formed is formed on the upper substrate 8 by using, for example, a photolithography method.

The resist layer is formed by supplying a resist material on the upper substrate 8 by a liquid phase process, and then using an i-line, an ultraviolet ray, an electron beam or the like through a photomask corresponding to the shape of the color filter 6 forming the resist material. It can be obtained by exposure and development.
The resist material to be used may be either a negative resist material or a positive resist material, and the same materials as those described for the constituent material of the color filter 6 can be used.

[3-Ab] Next, using this resist layer as a mask, a liquid material for forming a color filter is supplied to the opening using the liquid phase process as described above and dried, and then the resist layer is removed. Thus, the color filter 6 can be formed.
The liquid material for forming the color filter is prepared by dissolving or dispersing the constituent materials of the color filter 6 as described above in a solvent or a dispersion medium.
As the solvent or dispersion medium used for the preparation of the liquid material, the same solvents as described in the above step [2-B] can be used.

As a method of supplying the liquid material to the opening, it is preferable to select an ink jet method (droplet discharge method). According to the inkjet method, the liquid material can be selectively supplied to the inside of the opening. Therefore, the liquid material for each color corresponding to the color filters 6R, 6G, and 6B can be easily applied.
The resist layer can be removed by, for example, oxygen plasma or ozone vapor under atmospheric pressure or reduced pressure.

[3-B] Next, as shown in FIG. 3B, a black matrix 7 is formed between the color filters 6, that is, in a region where the upper substrate 8 is exposed.
The black matrix 7 can be obtained, for example, by supplying a liquid material for forming a black matrix to a region where the upper substrate 8 is exposed by using the liquid phase process as described above and then drying.
The liquid material for forming the black matrix is prepared by dissolving or dispersing the constituent materials of the black matrix 7 as described above in a solvent or a dispersion medium.
As the solvent or dispersion medium used for the preparation of the liquid material, the same solvents as described in the above step [2-B] can be used.

  As a method of supplying the liquid material to the region where the upper substrate 8 is exposed, it is preferable to select an ink jet method (droplet discharge method). According to the ink jet method, the liquid material can be selectively supplied to the inside of the region where the upper substrate 8 is exposed. Therefore, the waste of the liquid material can be omitted, and the constituent material of the black matrix 7 can be reliably prevented from adhering to the upper surface of the color filter 6.

[3-C] Next, the bank 31 is formed on the black matrix 7 so as to have almost the same pattern as the black matrix 7, that is, so that the color filter 6 is exposed.
[3-Ca] First, as shown in FIG. 3C, the constituent material of the bank 31 is mainly formed by the gas phase process and the liquid phase process as described above so as to cover the color filter 6 and the black matrix 7. A bank forming film 31 ′ is formed.
These methods are selected in consideration of the thermal stability of the constituent material of the bank 31 and physical and / or chemical characteristics such as solubility in a solvent. For example, when the bank 31 is composed of the conductive material as described above as a main material, a vapor phase process using a sputtering method, a vacuum deposition method, or the like is preferably selected as a method for forming the bank forming film 31 ′. The

[3-Cb] Next, as shown in FIG. 3D, a resist layer 38 corresponding to a region where the bank 31 is formed, that is, a region where the black matrix 7 is provided is formed on the bank formation film.
The resist layer 38 can be obtained in the same manner as described in the step [3-Aa] using a photomask corresponding to the shape of the bank 31.

[3-Cc] Next, as shown in FIG. 3E, unnecessary portions of the bank forming film are removed by wet etching using the resist layer 38 as a mask to expose the color filter 6. Thereafter, as shown in FIG. 3F, the resist layer 38 is removed to form the bank 31.
Here, according to the wet etching method, when an unnecessary portion of the bank forming film is removed, a side etching phenomenon occurs, so that the bank forming film can be removed in the thickness direction and the upper substrate is removed. Eight surface directions can also be removed. Therefore, the formed bank 31 can have a shape in which a cross-sectional area in a direction perpendicular to the thickness direction of the bank 31 increases toward the upper substrate 8, that is, a tapered shape.

The etchant used in the wet etching method is not particularly limited. For example, an aqueous solution of an alkali metal hydroxide such as NaOH or KOH, or an aqueous solution of an alkaline earth metal hydroxide such as Mg (OH) ₂ is used. , An aqueous solution of tetramethylammonium hydroxide, amide organic solvents such as N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMA), and the like, and these can be used alone or in combination. .
The resist layer can be removed by, for example, oxygen plasma or ozone vapor under atmospheric pressure or reduced pressure.

[4] Next, the TFT circuit substrate 20 and the color filter substrate 9 provided with the bank 31 are bonded to obtain the display device 10.
[4-A] First, the surface of the TFT circuit substrate 20 on which the organic EL element 1 is provided is opposed to the surface of the color filter substrate 9 on which the bank 31 is provided.
[4-B] Next, in a state where each organic EL element 1 and each color filter 6 correspond to each other, the TFT circuit substrate 20 and the color filter substrate 9 until the bank 31 and the cathode 5 come into contact with each other. Approach. As a result, each organic EL element 1 is surrounded by the bank 31 and a space 36 is formed.

This step is preferably performed in an inert gas atmosphere. Thereby, the inert gas can be reliably filled in the space 36.
In order to ensure that the bank 31 and the cathode 5 are in contact with each organic EL element 1 and each color filter 6, an alignment mark (not shown) is formed in advance on both substrates. The alignment can be performed relatively easily by aligning the alignment marks so that the alignment marks coincide with each other.
In the present embodiment, since the bank 31 has a tapered shape as described above, the bank 31 is formed so as to surround the organic EL element 1 relatively easily even when the alignment accuracy is low. It can be brought into contact with the cathode 5.

[4-C] Next, the TFT circuit substrate 20 and the color filter substrate 9 are bonded together by forming a sealing portion (not shown) that seals the gap formed at the edge thereof.
For example, the sealing portion may be formed of a liquid sealing portion forming material containing an organic material such as an acrylic resin, a polyimide resin, or an epoxy resin or a precursor thereof by a liquid phase process such as an inkjet method. After supplying to the area | region which forms a sealing part, it can form by making it dry.

Here, the TFT circuit substrate 20 and the color filter substrate 9 are joined together with the bank 31 and the cathode 5 in contact with each other as described in the above step [4-B], that is, through the bank 31 as a spacer. Done in state. Therefore, the TFT circuit substrate 20 and the color filter substrate 9 are formed with the width (height) in the thickness direction of the upper substrate 8 of the space 36 formed in the step [4-B] substantially constant. Can be joined.
The display device 10 can be manufactured through the steps as described above.

In the present embodiment, the case where the display device of the present invention is applied to the display device 10 including the organic EL element 1 having a top emission structure that extracts the light L ₁ and the light L ₂ from the cathode 5 side has been described. For example, the display device of the present invention can be applied to a display device including an organic EL element having a bottom emission structure that extracts the light L ₁ and the light L ₂ from the anode 3 side. In this case, the color filter substrate 9 and the bank 31 may be provided below the anode 3, that is, below the TFT circuit substrate 20.

<< Second Embodiment >>
Next, a second embodiment of the display device of the present invention will be described.
FIG. 2 is a longitudinal sectional view showing a second embodiment of the display device of the present invention. In the following description, the upper side in FIG. 2 is referred to as “upper” and the lower side is referred to as “lower”.

Hereinafter, the second embodiment will be described with a focus on differences from the first embodiment, and description of similar matters will be omitted.
The display device 10 shown in FIG. 2 is the same as the display device 10 of the first embodiment except that the bank 35 is configured by the first conductive portion 32 and the second conductive portion 33 instead of the bank 31. It is the same.

In the present embodiment, the bank 35 has a constant cross-sectional area in the direction perpendicular to the thickness direction of the bank 35 toward the organic EL element 1 side. That is, the angle formed by the surface of the black matrix 7 on the organic EL element 1 side and the inner surface of the bank 35 is 90 °. As a result, the light L ₁ reflected by the bank 35 can be emitted from the color filter 6 at an angle that is relatively perpendicular to the surface direction of the upper substrate 8. As a result, the contrast of the image or video displayed by the display device 10 increases.
Further, both the first conductive portion 32 and the second conductive portion 33 exhibit conductivity, and the first conductive portion 32 is required to have light reflectivity, but the second conductive portion 33 has light reflectivity. Not particularly required.

Although the average thickness of the 1st electroconductive part 32 is not specifically limited, It is preferable that it is about 0.1-5 micrometers, and it is more preferable that it is about 0.5-2 micrometers.
Although the average thickness of the 2nd electroconductive part 33 is not specifically limited, It is preferable that it is about 1-30 micrometers, and it is more preferable that it is about 5-10 micrometers.
As the constituent material of the first conductive portion 32, any material having conductivity can be used, and various conductive materials can be used. In particular, Cr, Au, Al, Ni, and alloys containing these materials are used. Of these, at least one of them is preferred. Thereby, the formed 1st electroconductive part 32 exhibits especially outstanding electroconductivity.

The constituent material of the second conductive portion 33 may be any material having conductivity and light reflectivity, and various conductive materials can be used. In particular, Ni, Co, Ag, and these are included. Preferably it is at least one of the alloys. Thereby, since the formed second conductive portion 33 has a color close to silver, the light L ₁ can be reflected on the inner surface of the second conductive portion 33 without changing its color tone.
Such a bank 35 can be formed as follows instead of the step [3-C] described in the first embodiment.

[3-C ′] Bank 35 Forming Step [3-C′a] First, as shown in FIG. 5A, the color filter 6 and the black matrix 7 are covered by a vapor phase process as described above, as shown in FIG. A conductive film 32 ′ mainly composed of the constituent material of the first conductive portion 32 is formed.
[3-C′b] Next, as shown in FIG. 5B, an opening is formed in a region where the bank 35 (second conductive portion 33) is formed, and the thickness of the opening is formed. A resist layer 39 which is substantially equal to the height of the second conductive portion 33 to be formed is formed on the conductive film 32 ′.
The resist layer 39 can be obtained in the same manner as described in the step [3-Aa] using a photomask corresponding to the shape of the bank 35.

[3-C′c] Next, as shown in FIG. 5C, the constituent material of the second conductive portion 33 is formed in the opening of the resist layer 39 by electroplating using the resist layer 39 as a mask. Precipitate. Thereafter, as shown in FIG. 5D, the resist layer 39 is removed to form the second conductive portion 33.
Here, according to the electroplating method, the plating solution containing the metal salt of the constituent material of the second conductive portion 33 is brought into contact with the first conductive portion 32 and a voltage is applied using the first conductive portion 32 as a cathode. Thus, the constituent material of the second conductive portion 33 can be deposited in the opening of the resist layer.
Moreover, as said metal salt, a sulfate, sulfamate, hydrochloride, nitrate etc. are used suitably, for example.
The resist layer can be removed by, for example, oxygen plasma or ozone vapor under atmospheric pressure or reduced pressure.

[3-C′d] Next, as shown in FIG. 5 (e), by removing the conductive film 32 ′ present in the opening of the second conductive part 33, that is, in the region corresponding to the color filter 6, The first conductive portion 32 is formed to obtain the bank 35.
For removing the conductive film, for example, one or more of physical etching methods such as plasma etching, reactive ion etching, beam etching, and optically assisted etching, and chemical etching methods such as wet etching are combined. Can be used.

<< Third Embodiment >>
Next, a third embodiment of the display device of the present invention will be described.
FIG. 6 is a longitudinal sectional view showing a third embodiment of the display device of the present invention. In the following description, the upper side in FIG. 6 is referred to as “upper” and the lower side is referred to as “lower”.
Hereinafter, the third embodiment will be described with a focus on differences from the first embodiment, and description of similar matters will be omitted.

The display device 10 shown in FIG. 6 is the same as that of the first embodiment except that the bank 31 is made of a conductive material, and the bank 31 and the cathode 5 are connected via a connection portion 34 having conductivity. This is the same as the display device 10 of the embodiment.
The conductive material constituting the bank 31 is preferably at least one of Al, Ni, Co, Ag, and alloys containing these, as described in the first embodiment.

Further, the connecting portion 34 is not particularly limited as long as it has conductivity, but the electrical conductivity is preferably higher than the electrical conductivity of the bank 31. Thereby, when a voltage is applied between the anode 3 and the cathode 5 via the bank 31 and the connecting portion 34, the electrical conductivity of the cathode 5 as a whole can be further improved.
Such a connecting part 34 may be selected according to the constituent material of the bank 31. For example, among Al, Au, Pt, Cu and alloys containing these, the resistance value is higher than that of the constituent material of the bank 31. The one with low is selected.

Although the average thickness of the connection part 34 is not specifically limited, It is preferable that it is about 0.1-3 micrometers, and it is more preferable that it is about 0.5-1 micrometer.
Such a connection part 34 is formed by performing the same process as the process [3-C] described when forming the bank 31 after the process [2] described in the first embodiment. be able to.

<Electronic equipment>
Such a display device 10 can be incorporated into various electronic devices.
FIG. 7 is a perspective view showing the configuration of a mobile (or notebook) personal computer to which the electronic apparatus of the present invention is applied.
In this figure, a personal computer 1100 includes a main body 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display. The display unit 1106 is rotatable with respect to the main body 1104 via a hinge structure. It is supported by.
In the personal computer 1100, the display unit included in the display unit 1106 is configured by the display device 10 described above.

FIG. 8 is a perspective view showing a configuration of a mobile phone (including PHS) to which the electronic apparatus of the invention is applied.
In this figure, a cellular phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204 and a mouthpiece 1206, and a display unit.
In the mobile phone 1200, the display unit is configured by the display device 10 described above.

FIG. 9 is a perspective view showing the configuration of a digital still camera to which the electronic apparatus of the present invention is applied. In this figure, connection with an external device is also simply shown.
Here, an ordinary camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an imaging device such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.

A display unit is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an imaging signal from the CCD, and functions as a finder that displays an object as an electronic image.
In the digital still camera 1300, the display unit is configured by the display device 10 described above.

A circuit board 1308 is installed inside the case. The circuit board 1308 is provided with a memory that can store (store) an imaging signal.
A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side of the case 1302 (on the back side in the illustrated configuration).
When the photographer confirms the subject image displayed on the display unit and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory of the circuit board 1308.

  In the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the data communication input / output terminal 1314 as necessary. Further, the imaging signal stored in the memory of the circuit board 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation.

The electronic apparatus of the present invention includes, for example, a television, a video camera, a viewfinder type, in addition to the personal computer (mobile personal computer) in FIG. 7, the mobile phone in FIG. 8, and the digital still camera in FIG. Monitor direct-view video tape recorder, laptop personal computer, car navigation system, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game device, word processor, workstation, videophone, security TV Monitors, electronic binoculars, POS terminals, devices equipped with touch panels (for example, cash dispensers and automatic ticket vending machines for financial institutions), medical devices (for example, electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiographs, ultrasound diagnostic devices, internal Endoscope display device), fish finder, various measuring instruments, Vessels such (e.g., gages for vehicles, aircraft, and ships), a flight simulator, various monitors, and a projection display such as a projector.
Although the display device and the electronic apparatus of the present invention have been described based on the illustrated embodiments, the present invention is not limited to these.
The display device of the present invention may be applied to a display device including an organic EL element having a structure in which a cathode, an organic semiconductor layer, and a cathode are stacked in this order on a substrate.

1 is a longitudinal sectional view showing a first embodiment of a display device of the present invention. It is a perspective view which shows 1st Embodiment of the display apparatus of this invention. It is a figure (longitudinal sectional view) for demonstrating the manufacturing method of the display apparatus shown in FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the display apparatus of this invention. FIG. 5 is a view (longitudinal sectional view) for explaining a manufacturing method of the display device shown in FIG. 4. It is a longitudinal cross-sectional view which shows 3rd Embodiment of the display apparatus of this invention. 1 is a perspective view showing a configuration of a mobile (or notebook) personal computer to which an electronic apparatus of the present invention is applied. It is a perspective view which shows the structure of the mobile telephone (PHS is also included) to which the electronic device of this invention is applied. It is a perspective view which shows the structure of the digital still camera to which the electronic device of this invention is applied. It is a longitudinal cross-sectional view which shows an example of the conventional display apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Organic EL element 3 ... Anode 31, 35 ... Bank 31 '... Bank formation film 32 ... 1st electroconductive part 32' ... Conductive film 33 ... 2nd electroconductive part 34 ... Connection part 36 ... ... Space 38, 39 ... Resist layer 4 ... Organic semiconductor layer 5 ... Cathode 6, 6R, 6G, 6B ... Color filter 7 ... Black matrix 8 ... Upper substrate 9 ... Color filter substrate 10 ... Display Device 20... TFT circuit substrate 21... Substrate 22... Circuit part 23 .. base protective layer 24... Driving TFT 241... Semiconductor layer 242 .. gate insulating layer 243. ...... Drain electrode 25 ...... First interlayer insulating layer 26 ...... Second interlayer insulating layer 27 ...... Wiring 1100 ...... Personal computer 1102 ...... Keyboard 1104 ...... Main body 1106 ...... Display unit 1200... Cellular phone 1202 .. operation button 1204 .. earpiece 1206... Mouthpiece 1300 .. digital still camera 1302. ... Circuit board 1312 ... Video signal output terminal 1314 ... Input / output terminal for data communication 1430 ... Television monitor 1440 ... Personal computer 900 ... Substrate 901 ... Pixel electrode 902 ... Light emitting layer 903 ... Counter electrode 910 ... Organic EL element 911 ... Color filter substrate 912 ... Color filter 913 ... Black matrix 915 ... Space 920 ... Display devices L ₁ , L ₂ , l _{1 to} l ₈ ... Light

Claims (20)

A plurality of organic light-emitting elements comprising a pair of electrodes and an organic semiconductor layer provided between these electrodes and including a light-emitting layer;
And a bank provided so as to partition each of the organic light emitting elements, wherein the inner surface of the bank is constituted by a light reflecting surface having a function of reflecting light from the organic light emitting elements. .   The display device according to claim 1, wherein the bank has a portion whose width decreases toward the organic light emitting element.   The display device according to claim 2, wherein an angle formed between a surface of the bank opposite to the organic light emitting element and an inner surface of the bank is 60 ° or more and less than 90 °.   The display device according to claim 1, wherein the bank has a reflectance of 60 to 99.8% on an inner surface thereof.   The display device according to claim 4, wherein the bank has an inner surface roughness Ra (specified in JIS B 0601) of 100 nm or less.   The display device according to claim 1, wherein an electrode on the opposite side of the bank of the organic light emitting element has light reflectivity. Of the pair of electrodes included in the organic light emitting device, at least the bank side electrode is configured with a common electrode, and at least the inner surface of the bank is configured with a conductive material,
The display device according to claim 1, wherein the electric conductivity of the common electrode is improved by bringing the bank into contact with the common electrode.   The display device according to claim 7, wherein the bank and the common electrode are connected via an electrical connection unit.   The display device according to claim 8, wherein the electrical conductivity of the connection portion is higher than the electrical conductivity of the bank.   The display device according to claim 7, wherein the conductive material is mainly composed of at least one of Al, Ni, Co, Ag, and an alloy containing these.   The display device according to claim 1, further comprising: a switching element that switches ON / OFF of energization to the organic light emitting element on a side opposite to the bank of the light emitting element.   The display device according to claim 1, wherein each of the organic light emitting elements emits white light.   13. A black matrix having an opening corresponding to each of the organic light emitting elements and blocking transmission of light from the organic light emitting elements is provided on a side of the bank opposite to the organic light emitting elements. The display apparatus in any one of.   The display device according to claim 13, wherein a dye layer is provided in each of the openings, and a color tone of light from each of the organic light emitting elements is converted when passing through the dye layer.   The display device according to claim 13 or 14, wherein a space between the organic light emitting element and the black matrix is sealed, and the space is filled with an inert gas.   The display device according to claim 13, wherein the bank is provided in a pattern substantially equal to the pattern of the black matrix.   The display device according to claim 16, wherein an opening area of the opening is larger than a plane area of an electrode having a smaller plane area among a pair of electrodes included in the organic light emitting element. The plane area towards the electrode plane area is small and A [μm ^2], when the opening area of the opening was B [μm ^2], satisfy the relation B / A is 1.0 to 1.5 The display device according to claim 17. The opening has a rectangular shape in plan view,
19. The relationship according to claim 16, wherein D / C satisfies a relationship of 0.2 to 5 where an average height of the bank is C [μm] and an average width of the opening is D [μm]. The display device described in 1.   An electronic apparatus comprising the display device according to claim 1.

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