JP2008066054A - Electro-optical device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To emit light from the region nearly equal to the bottom face of an aperture, and also suppress variations in luminance of each light-emitting element. <P>SOLUTION: The optical head 1A is provided with a plurality of positive electrodes 11, a lyophilic layer 12, a liquid repellent layer 13, and a common bank 50A. Pixel apertures 50A are formed corresponding respectively to the plurality of positive electrodes 11. In this case, the apertures of the same shape are formed in the lyophilic layer 12 and the liquid repellent layer. A plurality of pixel apertures 50B are formed inside the common bank 50A. Furthermore, a hole injection layer 20 which injects positive holes is formed on the positive electrode 11 of the pixel aperture 50B, and a luminous layer 21 is formed inside the common bank 50A and on the hole injection layer 20 and the liquid repellent layer 13. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an electro-optical device whose optical characteristics change according to an electrical action, and a manufacturing method thereof.

There is an organic EL (Electro luminescent) panel as an electro-optical device. In an organic EL panel, a plurality of organic EL elements are arranged on a substrate as a plurality of light emitting elements whose light emission characteristics are changed by electric energy. This organic EL panel is used as an optical head or an image display device.
As such a light emitting element, Patent Document 1 discloses a structure shown in FIG. In the structural example shown in FIG. 12A, the hydrophilic first layer 21 is formed on the substrate 200 on which the pixel electrode is formed.
A layer in which 0 and a liquid repellent second layer 220 are laminated. In this example, the first layer 210 has an opening Q.
Protrudes inside. Moreover, the opening shape of the 1st layer 210 and the 2nd layer 220 becomes the same as another structural example.
In these configurations, the hole injection layer and the light emitting layer are sequentially stacked in the opening Q. The material solution for the hole injection layer is aqueous, whereas the material solution for the light emitting layer is an organic solution. Therefore, the material solution for the hole injection layer wets and spreads on the inner peripheral surface of the first layer 210, and the material solution for the light emitting layer wets and spreads on the inner peripheral surface of the second layer.
JP 2002-372921 (FIGS. 10 and 11)

By the way, since the first layer 210 has a strong affinity with the material solution of the hole injection layer, in the structural example shown in FIG. 12A, the material solution spreads over the first layer 210 and is dried when the region is dried. It becomes a film as it is. In this case, the resistance of the hole injection layer may be reduced. Then, current flows also in a region wider than the bottom surface of the opening Q, and the light emitting region is enlarged. When the light emitting element having such a structure is applied to an optical head, the light emitting area is enlarged, so that the photosensitive diameter on the photosensitive drum is enlarged, and the printing resolution is lowered. In the case of a display, the same effect as an increase in the light emitting area can be obtained, but there is a problem that the display resolution is lowered.

On the other hand, in the structural example shown in FIG. 12B, the material liquid for forming the light emitting layer is the second layer 22.
It has the property of being easily wetted with respect to zero. When the material liquid of the light emitting layer is formed into the opening Q by ink-jet film formation, the material liquid wets and spreads on the surface of the second layer, and dries in the wet spread shape. Then, since the formation region differs for each pixel, the thickness and shape of the formed film vary. As a result, there is a problem that the luminance of each light emitting element varies.

The present invention has been made in view of the above-described circumstances, and provides an electro-optical device that emits light in a region substantially equal to the bottom surface of the opening and suppresses variation in luminance of each light-emitting element, and a method for manufacturing the same. Let it be a solution issue.

The electro-optical device according to the invention includes a plurality of pixel electrodes (for example, 11 in FIG. 2 and 111 in FIG. 7).
And a lyophilic layer (for example, 12 in FIG. 2, 1 in FIG. 7).
12), a liquid repellent layer (for example, 13 in FIG. 2, 61A in FIG. 7) formed on the lyophilic layer, and the plurality of pixel electrodes, respectively. A plurality of pixel openings (for example, 50B in FIGS. 2 and 7) formed in the liquid repellent layer, and a common bank (for example, 50A in FIG. 2, 60A in FIG. 7) surrounding the plurality of pixel openings. And the lyophilic layer has a stronger affinity for the liquid than the lyophobic layer.

The electro-optical device according to the present invention includes an injection layer for injecting electrons or holes provided on the pixel electrode located in the pixel opening, and an organic semiconductor formed continuously inside the common bank. And a layer.
The injection layer has a function of injecting electrons or holes into the organic semiconductor layer. The lyophilic layer is exposed on the inner peripheral surface of the pixel opening, and the lyophilic layer has a stronger affinity for the injection layer forming material liquid for forming the injection layer than the liquid repellent layer. The forming material liquid spreads wet inside the pixel opening.
Thereby, application failure can be prevented. Further, since the injection layer is formed only in the pixel opening, even if the specific resistance of the injection layer is lowered, light is not emitted outside the pixel opening and the light emission shape can be defined. In addition, the present invention has a common bank surrounding a plurality of pixel openings, and an organic semiconductor layer is formed there. In such a structure, since the organic semiconductor layer can be formed on the entire inner side of the common bank having a larger area than the pixel opening, the film thickness of the organic semiconductor layer in the pixel opening can be made uniform. . From the viewpoint of making the film thickness uniform, the distance from the boundary in the short direction of the common bank to the pixel opening is preferably 50 μm or more, and more preferably 100 μm or more. The distance from the longitudinal boundary of the common bank to the pixel opening is 3 m.
m or more is preferable.

In the electro-optical device according to the aspect of the invention, the pixel opening may have substantially the same shape in plan view in the lyophilic layer and the liquid repellent layer.
According to the present invention, the lyophilic layer does not protrude inside the pixel opening of the lyophobic layer. Accordingly, the pixel can emit light in the region of the pixel electrode exposed on the bottom surface of the pixel opening, and the area of the light emitting region can be defined. As a result, when the electro-optical device is used as an optical head, the quality of printing can be improved, and when it is used as a display device, the resolution of a display image can be improved.

As a more specific aspect of the electro-optical device described above, the liquid repellent layer may have a planar shape in which holes of the plurality of pixel openings are opened (for example, the first and second embodiments). . In this case, when etching the lyophilic layer inside the pixel opening, it is not necessary to protect the lyophilic layer outside the pixel opening, and the process can be simplified.
Alternatively, the liquid repellent layer may be formed as an individual bank that surrounds the periphery of the pixel opening in each of the plurality of pixel openings. In this case, the organic semiconductor layer forming material liquid for forming the organic semiconductor layer can be easily wetted and spread over the entire inside of the common bank, and formation defects can be prevented.

In the electro-optical device, it is preferable that a plurality of the common banks are formed, and the organic semiconductor layer formed in each of the plurality of common banks emits light in a single color. For example, when displaying a color image, an organic semiconductor layer corresponding to a plurality of emission colors (for example, RGB) is used. A plurality of pixel openings are formed inside the common bank, and the pixel openings function as pixels, but the organic semiconductor layer formed in the common bank emits light in a single color, and thus organic semiconductors having different emission colors Layers do not mix in one common bank. Accordingly, when forming a plurality of light emitting organic semiconductor layers, color mixing can be prevented at the time of painting. Further, by arranging the common banks in a stripe shape, it is possible to display with RGB color stripes.

Here, it is preferable that the common bank has a stronger non-affinity with respect to the organic semiconductor layer forming material liquid for forming the organic semiconductor layer than the liquid repellent layer. If the affinity of the common bank to the organic semiconductor layer forming material liquid is the same as that of the liquid repellent layer, the organic semiconductor layer forming material liquid does not spread and separate when filling the inside of the common bank with the organic semiconductor layer forming material liquid Sometimes. According to this invention, since the common bank has stronger affinity for the organic semiconductor layer forming material liquid than the liquid repellent layer, a large amount of organic semiconductor layer forming material liquid is applied (applied), and the organic semiconductor layer forming material liquid is used. Can be prevented from separating. Furthermore, the organic semiconductor layer forming material liquid can be prevented from overflowing from the common bank, and the region of the organic semiconductor layer can be strictly defined. Thereby, variation in the thickness of the organic semiconductor layer for each substrate or for each common bank is suppressed, and an organic semiconductor device with stable quality can be manufactured.

More specifically, the common bank is preferably made of a fluorinated resin.
In this case, the non-affinity for the organic semiconductor layer forming material liquid can be strengthened. The lyophilic layer is preferably made of an inorganic material. Further, the inorganic material preferably contains silicon oxide, silicon nitride, or silicon oxynitride. In this case, the affinity of the lyophilic layer to the injection layer forming material liquid can be increased by using the injection layer forming material liquid as an aqueous solvent, and injection is performed when the pixel opening is filled with the injection layer forming material liquid. The layer forming material liquid is easy to spread and prevent application failure. Further, since it has an insulating property, it is possible to prevent nearby pixels from emitting light when a certain pixel is driven. Further, since it is generally used as an insulating material of a semiconductor device, film formation / processing is easy. Meanwhile, the liquid repellent layer and the common bank are preferably made of an organic material. Note that the electro-optical device described above preferably includes an electrode (for example, the cathode 30 shown in FIG. 2) formed above the organic semiconductor layer. In this case, the impedance can be reduced by using a common electrode for a plurality of pixels.

Next, a method for manufacturing an electro-optical device according to the invention corresponds to a step of forming a lyophilic layer on a substrate on which a plurality of pixel electrodes are formed, and each of the plurality of pixel electrodes on the lyophilic layer. A step of forming a liquid repellent layer having a plurality of openings, a step of forming a common bank including the plurality of openings on the inside of the liquid repellent layer, and the lyophilic liquid using at least the liquid repellent layer as an etching mask. Etching a layer to form a pixel opening exposing the pixel electrode; forming an injection layer for injecting electrons or holes over the pixel electrode in the pixel opening; and And a step of forming an organic semiconductor layer inside.
According to this manufacturing method, an electro-optical device having a structure in which the lyophilic layer and the liquid repellent layer have the same opening shape and a structure in which common banks having different opening shapes are stacked can be manufactured. Moreover, in the step of etching the lyophilic layer, the lyophilic layer is etched using the already formed lyophobic layer as an etching mask, so that the opening shapes of the lyophilic layer and the lyophobic layer can be accurately aligned.

Here, the lyophilic layer is preferably etched by plasma etching (dry etching). In this case, an undercut in which the bottom of the liquid repellent layer is etched can be suppressed, so that an opening with a smaller shape difference can be formed.
Further, in the step of forming the injection layer, it is preferable to fill the pixel opening with an injection layer forming material liquid for forming the injection layer by an inkjet method. According to this method, since a prescribed amount of the injection layer forming material liquid can be applied with high positional accuracy, there is no protrusion from the pixel opening, and an injection layer having a predetermined thickness can be formed.
Furthermore, in the step of forming the organic semiconductor layer, it is preferable that an organic semiconductor layer forming material liquid for forming the organic semiconductor layer is filled inside the common bank by an inkjet method. According to this method, since the organic semiconductor layer forming material liquid can be applied with high positional accuracy, the organic semiconductor layer having a predetermined thickness can be formed without protruding from the common bank.

Embodiments according to the present invention will be described below with reference to the accompanying drawings. In the drawings, the ratio of dimensions of each part is appropriately changed from the actual one.
<1. First Embodiment>
FIG. 1 is a plan view of the electro-optical device according to the first embodiment of the invention. The electro-optical device according to the first embodiment is an optical head 1A. As shown in this figure, the optical head 1A has a common bank 50A having a concave portion on the inner side, and a plurality of light emitting elements P are arranged in a staggered manner in two rows inside the common bank 50A. The light emitting element P has a pixel opening 50B. For example, the diameter of the pixel openings 50B is 40 μm, the pitch in the longitudinal direction is 84.5 μm, and a two-row staggered array is formed. The inter-column pitch is 84.5 μm. Thereby, a resolution of 600 dpi can be realized. It should be noted that the light emitting elements P may be arranged in 4 rows and 1200 dpi, or may be arranged in 8 rows and 2400 dpi so as to have a high resolution.

As will be described later, the light emitting layer 21 (organic semiconductor layer) is formed inside the common bank 50A. From the viewpoint of making the film thickness uniform, the pixel opening 5 is formed from the boundary in the short direction of the common bank 50A.
The distance Y1 to 0B needs to be 50 μm or more, and more preferably 100 μm or more. Further, the distance X from the longitudinal boundary of the common bank 50A to the pixel opening 50B
1 is preferably 3 mm or more.

2 is a cross-sectional view taken along the line Z1-Z1 ′ of the optical head shown in FIG. FIG. 3 is a perspective sectional view of the portion M shown in FIG. However, the hole injection layer 20, the light emitting layer 21, and the cathode 30 are excluded. On the substrate 10, drive circuits such as wiring, a driving TFT (Thin Film Transistor), and an interlayer insulating film are formed as necessary. ITO ((Indium Tin Oxide) on the substrate 10
A transparent anode 11 such as is formed. The anode 11 is connected to the drive circuit through a contact hole in the interlayer insulating film and functions as a pixel electrode (not shown).
A lyophilic insulating film 12 is laminated on the anode 11 and the substrate 10. As a material for the lyophilic insulating film 12, inorganic materials such as silicon oxide, silicon nitride, and silicon oxynitride are suitable. The lyophilic insulating film 12 has a property that the solution spreads wet. The thickness of the lyophilic insulating film 12 is 50 to 300.
nm is preferred. If the film thickness is larger than that, 1) the film formation time becomes longer, 2) the etching processing accuracy deteriorates, and 3) the film thickness of the light emitting layer 21 to be formed later becomes difficult to be uniform in the pixel. .

A lyophobic layer 13 is laminated on the lyophilic insulating film 12 (lyophilic layer), and an opening having the same shape as the opening of the lyophilic insulating film 12 is formed. For the liquid repellent layer 13, for example, a resin made of an organic material such as photosensitive acrylic or polyimide can be used. The liquid repellent layer 13 repels an aqueous solution, while the organic solvent has a property that is slightly difficult to repel. The film thickness of the liquid repellent layer 13 is 100-30.
0 nm. If it is thinner than this, the ratio of the film thickness variation to the target film thickness becomes too large, and the dimensional accuracy of the opening cannot be maintained. If it is thicker than this, the film thickness of the light emitting layer 21 to be formed later becomes uniform. There is an evil that it is difficult.

The opening of the lyophilic insulating film 12 and the opening of the liquid-repellent layer 13 are not limited to the case where the openings coincide with each other in plan view, but also includes a case where the opening is slightly shifted due to a manufacturing error. . These openings are formed by the number of anodes 11. A common bank 50A is formed on the liquid repellent layer 13 so as to surround all the pixel openings 50B formed therein. Similar to the liquid repellent layer 13, the common bank 50A is a resin made of an organic material such as photosensitive acrylic or polyimide. That is, the common bank 50A functions as a second liquid repellent layer and repels an aqueous solution like the liquid repellent layer 13, while the organic solvent has a property that is slightly difficult to repel. Common bank 50
The film thickness of A is about 1 to 3 μm.

The hole injection layer 20 is formed on the anode 11 (pixel electrode) of the pixel opening 50B. As a material of the hole injection layer 20, for example, PEDOT-PSS which is a kind of conductive polymer
Is used. A light emitting layer 21 made of an organic EL material is formed inside the hole injection layer 20 and the common bank 50A. In addition, a cathode 30 is provided on the common bank 50A and the light emitting layer 21.
Is formed. The light emitting element P includes an anode 11, a hole injection layer 20, a light emitting layer 21, and a cathode 30. Furthermore, although omitted in FIG. 2, sealing is performed to protect the light emitting element P from the outside air. As the sealing structure, so-called can sealing, solid sealing, thin film sealing, or the like can be used.

FIG. 4 shows a manufacturing process of the optical head 1A. First, an anode 11 is formed on a substrate 10 as shown in FIG. In this step, the anode 11 is formed in a predetermined region by patterning the ITO film.

Next, a lyophilic insulating film 12 is formed as shown in FIG. Suitable materials are silicon oxide, silicon nitride, and silicon oxynitride, but any insulating material that can be easily deposited / etched can be used. The film formation may be performed by a known method, and the method is not limited. For example, the material is applied by a method such as spin coating, spray coating, roll coating, die coating, dip coating, CVD, or sputtering. The thickness of the lyophilic insulating film 12 is suitably 50 to 300 nm. When the film thickness is larger than that, there are adverse effects that the film formation time becomes long, the etching processing accuracy deteriorates, and the film thickness of the light emitting layer 21 to be formed later becomes difficult to be uniform in the pixel.

Next, as shown in FIG. 3C, a liquid repellent layer 13 is formed on the lyophilic insulating film 12 using an organic material such as photosensitive acrylic or polyimide. For the liquid repellent layer 13, any method such as a printing method or a lithography method can be selected. When the printing method is used, the organic material is directly applied to the bank shape by an arbitrary method such as intaglio, lithographic and letterpress. When using the lithography method, apply the material by a predetermined method such as spin coating, spray coating, roll coating, die coating, dip coating, etc., apply a mask according to the shape of the liquid repellent layer 13, and expose and develop the resist To form an acrylic or polyimide resin having a predetermined shape. Finally, it is fired to form the liquid repellent layer 13.
The thickness of the liquid repellent layer 13 is 0.5 μm or less, and more desirably 0.3 μm or less.

Next, a common bank 50A is formed on the liquid repellent layer 13 as shown in FIG. The common bank 50A is formed in the same process using the same material as the liquid repellent layer 13 described above. The thickness of the common bank 50A needs to be about 1 to 3 μm. The width of the inner periphery of the common bank 50A is the width of the pixel formation region + 200 μm, and the length is the length of the pixel formation region + 6 mm.

Next, as shown in FIG. 5E, a pixel opening 50B that partially exposes the anode 11 is formed. In this step, the lyophilic insulating film 12 is etched using the liquid repellent layer 13 as an etching mask. The liquid repellent layer 13 is an organic material and can act as a resist. Therefore, only the lyophilic insulating film 12 can be selectively etched by selecting an etching material. Etching may be either dry etching that does not use a solution or wet etching that uses a solution, but dry etching is preferred because undercut is unlikely to occur. For example, it is preferable to perform etching by a plasma etching method. By this process, the liquid repellent layer 13
An opening having the same shape as the opening formed in the step can be formed in the lyophilic insulating film 12. Thereafter, a lyophilic process using oxygen plasma and a lyophobic process using CF 4 plasma are performed to make the surface of the anode 11 lyophilic, and the surfaces of the lyophobic layer 13 and the common bank 50A have lyophobic properties.
That is, the surfaces of the lyophilic insulating film 12 and the anode 11 are the liquid repellent layer 13 and the common bank 50A.
Compared with, the affinity with respect to an aqueous solution becomes strong. Further, the liquid repellent layer 13 and the common bank 50A are fluorinated by the liquid repellent treatment with CF4 plasma.

Next, the hole injection material solution is driven into the pixel opening 50B by an inkjet method and dried to form the hole injection layer 20. PED in which hole injection material uses water-based solvent in particular
In the case of OT-PSS, the hole injection layer 20 is repelled by the liquid repellent layer 13, so that the hole injection layer 20 has a pixel opening 50 </ b> B.
It is formed only inside. Further, since the lyophilic insulating film 12 is exposed on the inner end face of the pixel opening 50B, the hole injection material solution tends to wet and spread throughout the pixel opening 50B, resulting in poor formation of the hole injection layer 20. Can be reduced.

Thereafter, the light emitting material solution (organic solution) is driven into the common bank 50A according to the ink jet method and dried to form the light emitting layer 21. Since the luminescent material solution uses an organic solvent, it spreads to some extent even on the surface of the liquid repellent layer 13. The concentration of the light emitting material solution is decreased, the amount of the solution to be injected into the common bank 50A is increased so that the solution is not repelled, and the adjacent droplets slightly overlap each other at the position where the droplets are injected by inkjet. Make adjustments as necessary.

Thus, the light emitting layer 21 is formed in the entire common bank 50A having a larger area than the pixel opening 50B. In the outer peripheral portion of the common bank 50A, the light emitting layer 21 is thickly attached to the bank taper portion, so the film thickness uniformity is not good. On the other hand, the pixel opening 50B at the center of the common bank 50A
In, the light emitting layer 21 is formed flat. The term “flat” as used herein means that the surface is not flattened so that the surface is flat even if there are irregularities in the lower layer, but the thickness is, for example, 100 nm regardless of the irregularities in the lower layer and measured anywhere. Thereafter, Ca / Al or the like is deposited to form the cathode 30. Further, a desiccant is added and sealed.

<2. Second Embodiment>
FIG. 5 is a plan view of the electro-optical device according to the second embodiment of the invention. The electro-optical device 2 of the second embodiment is a display device having an RGB stripe arrangement. For example, a 40-inch display having 1920 × RGB × 1080 pixels. A light emitting layer 21 for each color of RGB is formed inside each common bank 50A. However, the light emitting layer 21 having a single emission color is formed in one common bank 50A. As a result, no color mixing occurs when the light emitting layer 21 is applied by the ink jet method. For example, the pixel opening 50B is 230 × 76 μm oval, the pixel pitch is 461 μm, and the pixel pitch is 154 μm.
The pixel opening size, the pixel pitch, the pixel pitch, and the common bank size can be appropriately changed according to the panel size, the number of pixels, and the aperture ratio. In addition, a driving circuit such as a wiring, a driving TFT, or an interlayer insulating film may be formed on the substrate 10 as necessary.
The manufacturing method of the electro-optical device 2 is the same as that of the first embodiment except that the light-emitting layer 21 formed inside the common bank 50A is coated according to the light emission color, and thus the description thereof is omitted.

<3. Third Embodiment>
FIG. 6 is a plan view of an electro-optical device according to a third embodiment of the invention. The electro-optical device of the third embodiment is an optical head 1B. As shown in this figure, the optical head 1B has a common bank 60A whose inside is a recess. A plurality of light emitting elements P are arranged in a staggered manner in two rows inside the common bank 60A. The light emitting element P has a pixel opening 50B. An individual bank 61A surrounding the pixel opening 50B is provided. The individual bank 61A has a pixel opening 50B.
It has a ring shape formed along the periphery. The pixel openings 50B have, for example, a pixel opening 50B with a diameter of 40 μm and a longitudinal pitch of 84.5 μm, and a two-row staggered arrangement. The inter-column pitch is 84.5 μm. Thereby, a resolution of 600 dpi can be realized. It should be noted that the light emitting elements P are arranged in four rows, 1200 dpi, or 8
It may be arranged in rows and have a high resolution such as 2400 dpi. As will be described later, a light emitting layer 121 (organic semiconductor layer) including an interlayer is formed inside the common bank 60A. Further, from the viewpoint of making the thickness of the light emitting layer 121 formed inside the common bank 60A uniform, the distance Y1 from the boundary in the short direction of the common bank 60A to the pixel opening 50B is 50 μm.
It is necessary to be above, and it is desirable that it is 100 μm or more. Common bank 6
The distance X1 from the boundary in the longitudinal direction of 0A to the pixel opening 50B is preferably 3 mm or more.

FIG. 7 is a cross-sectional view taken along the line Z2-Z2 ′ of the optical head shown in FIG. FIG. 8 shows a perspective sectional view of the portion M ′ shown in FIG. However, the hole injection layer 120, the light emitting layer 121, and the cathode 13
0 is excluded. The substrate 110 is provided with wiring and driving TFTs (Thin Film Transi) as necessary.
stor), and a drive circuit such as an interlayer insulating film are formed. On the substrate 110, ITO (Indium
A transparent anode 111 such as Tin Oxide is formed. The anode 111 is connected to a drive circuit through a contact hole in the interlayer insulating film (not shown).
A lyophilic insulating film 112 is stacked on the anode 111 and the substrate 110. Lipophilic insulating film 11
As the second material, inorganic materials such as silicon oxide, silicon nitride, and silicon oxynitride are suitable. The lyophilic insulating film 112 has a property that the solution spreads wet. The thickness of the lyophilic insulating film 112 is equal to or greater than the thickness of the hole injection layer 120. Specifically, the film thickness is preferably 50 to 300 nm. If the film thickness is larger than that, 1) the film formation time becomes longer, 2) the etching processing accuracy deteriorates, and 3) the film thickness of the light emitting layer 121 to be formed later becomes difficult to be uniform in the pixel. .

A pixel opening 50B is formed in the lyophilic insulating film 112 (lyophilic layer). Pixel opening 50B
A hole injection layer 120 is formed on the anode 111. As a material of the hole injection layer 120, for example, PEDOT-PSS which is a kind of conductive polymer is used.
The individual bank 61 is provided above the lyophilic insulating film 112 and around the pixel opening 50B.
A is formed. A water-repellent material is used for the individual bank 61A. For example, a resin made of an organic material such as photosensitive acrylic or polyimide can be used. Individual bank 6
The width of 1A is preferably 5 to 20 μm, and the bank height is preferably 0.1 to 2 μm.
The film forming conditions are that the hole injection layer 120 can be formed and the light emitting layer 121 including the interlayer can be formed in the common bank 60A. By using a water-repellent organic material for the individual bank 61A, the hole injection layer 120 is formed on the pixel opening 5 by the inkjet method.
When filling 0B, the material liquid can be prevented from leaking out of the pixel opening 50B.

Further, a common bank 60A is formed on the lyophilic insulating film 112 so as to surround the plurality of individual banks 61A. Similar to the individual bank 61A, the common bank 60A is made of a resin such as photosensitive acrylic or polyimide and has water repellency. A light emitting layer 121 including an interlayer is formed inside the common bank 60A by an inkjet method. Light emitting layer 121
The bank height of the common bank 60A is set to 2 in order to stably hold the material liquid for forming
It is preferable to be set to ˜3 μm.
A cathode 130 is formed on the common bank 60 </ b> A and the light emitting layer 121. The light emitting element P is
An anode 111, a hole injection layer 120, a light emitting layer 121, and a cathode 130 are included. In addition, although omitted in FIG. 7, sealing is performed to protect the light emitting element P from the outside air. As the sealing structure, so-called can sealing, solid sealing, thin film sealing, or the like can be used.

FIG. 9 shows a manufacturing process of the optical head 1B. First, an anode 111 is formed on a substrate 10 as shown in FIG. In this step, the anode 111 is formed in a predetermined region by patterning the ITO film.

Next, a lyophilic insulating film 112 is formed as shown in FIG. Suitable materials are silicon oxide, silicon nitride, and silicon oxynitride, but any insulating material that can be easily deposited / etched can be used. The film formation may be performed by a known method, and the method is not limited. For example,
Spin coat, spray coat, roll coat, die coat, dip coat, CVD,
The material is applied by a method such as sputtering.

Next, as shown in FIG. 3C, the individual bank 61A is formed on the lyophilic insulating film 112 using an organic material such as photosensitive acrylic or polyimide. For the individual bank 61A, an arbitrary method such as a printing method or a lithography method can be selected. When using the printing method, intaglio, lithographic,
An organic material is directly applied to the bank shape by any method such as letterpress. When using the lithography method, apply the material by a predetermined method such as spin coating, spray coating, roll coating, die coating, dip coating, etc., apply a mask according to the shape of the individual bank 61A, and expose and develop the resist. An acrylic or polyimide resin having a predetermined shape is formed. Finally, it is fired to form individual banks 61A.
Next, as shown in FIG. 4D, a resist pattern is formed outside the individual bank 61A in a region where the lyophilic insulating film 112 is desired to be protected. At this time, the resist pattern is in the individual bank 61.
It is formed so as to partially overlap A.
Thereafter, the lyophilic insulating film 112 is dry-etched using the individual bank 61A as a mask,
A pixel opening 50B that partially exposes the anode 111 is formed, and the resist pattern is peeled off.

Next, as shown in FIG. 5E, the common bank 60A is formed so as to surround the plurality of individual banks 61A. The common bank 60A is made of a water-repellent material, for example, photosensitive acrylic or polyimide. For the film formation of the common bank 60A, an arbitrary method such as a printing method or a lithography method can be selected as in the case of the individual bank 61A. The common bank 60A and the individual bank 61A are arranged so as to ensure the flatness of the light emitting layer 121 including the interlayer. It is desirable that the end faces of the individual bank 61A and the common bank 60A have a distance of at least about 50 μm in the lateral direction and at least about 3 mm in the longitudinal direction. The lyophilic insulating film 112 is the uppermost surface between the individual bank 61A and the common bank 60A. Since the common bank 60A is formed in a separate process from the individual bank 61A, the film-forming accuracy of the light emitting layer 121 can be further improved by using a material having higher water repellency than the water repellent material used in the individual bank 61A. It becomes possible.
Thereafter, a lyophilic process using oxygen plasma and a lyophobic process using CF4 plasma are performed.
The surface of the anode 111 is made lyophilic, and the surface of the individual bank 61A and the common bank 60A is made lyophobic. That is, the lyophilic insulating film 112 and the surface of the anode 111 have a stronger affinity for the solution than the individual bank 61A and the common bank 60A. Further, the individual bank 61A and the common bank 60A are fluorinated by the liquid repellency treatment using CF4 plasma. The common bank 60A has a liquid repellency (non-affinity) with respect to an organic solution compared to the individual bank 61A.
Becomes stronger.

Next, a hole injection layer 120 is formed as shown in FIG. 5F, and then a light emitting layer 121 including an interlayer is formed as shown in FIG. The film forming method uses an inkjet method, and the hole transport layer 121 draws a pixel in the individual bank 61A corresponding to the pixel opening 50B. The light emitting layer 121 including the interlayer is drawn in the common bank 60A. Each of the inks containing the material is landed by ink jet, and then deposited by a vacuum dryer. In addition, the light emitting layer 121
In addition to the ink jet method, a dispenser method can be considered as a wet method.
After the hole injection layer 120 is individually drawn by the inkjet method, the light emitting layer 121 is drawn in the common bank 60A by a dispenser. In this case, process time can be shortened with respect to the inkjet method.

<4. Fourth Embodiment>
FIG. 10 is a plan view of an electro-optical device according to a fourth embodiment of the invention. The electro-optical device 2B according to the fourth embodiment is an RGB stripe array display device. For example, a 40-inch display having 1920 × RGB × 1080 pixels. A light emitting layer 21 for each color of RGB is formed inside each common bank 60A. However, a light emitting layer 121 having a single emission color is formed on the lyophilic insulating film 112 inside one common bank 60A. by this,
No color mixing occurs when the light emitting layer 121 is applied by the ink jet method. For example, the pixel opening 50B is 230 × 76 μm oval, the pixel pitch is 461 μm, and the pixel pitch is 154 μm.
The pixel opening size, the pixel pitch, the pixel pitch, and the common bank size can be appropriately changed according to the panel size, the number of pixels, and the aperture ratio. In addition, a driving circuit such as a wiring, a driving TFT, or an interlayer insulating film may be formed on the substrate 110 as necessary.
The manufacturing method of the electro-optical device 2B is the same as that of the third embodiment except that the light-emitting layer 121 formed inside the common bank 60A is separately applied according to the light emission color, and thus the description thereof is omitted.

<5. Modification>
(1) In the first and second embodiments described above, the anode 11, the hole injection layer 20, the light emitting layer 21, and the cathode 30 are stacked in this order to form the light emitting element P. In the third and fourth embodiments described above, Anode 11
1, the hole injection layer 120, the light emitting layer 121, and the cathode 130 are stacked in this order to form the light emitting element P. The cathode, the electron injection layer for transporting electrons, the light emitting layer, and the anode are arranged on the substrates 10 and 110. The light emitting element P may be formed by stacking. Also in this case, the material solution for forming the electron injection layer is composed of an aqueous system, so that the material solution can be wetted and spread inside the pixel opening 50B, and the occurrence of defects due to application defects can be suppressed. it can.

(2) FIG. 11 shows a configuration of a personal computer that is an electronic apparatus using the electro-optical device 2A or 2B. The personal computer 1030 includes a display unit 1031 and a 10 main body unit 32 as display units. The main body portion 1032 is provided with a power switch 1033 and a keyboard 1034. According to the personal computer 1030, since the electro-optical device 2A or 2B is used as the display unit 1031, an image can be displayed with sufficiently high quality even in response to a request for higher definition and a larger screen.

1 is a plan view of an optical head according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along Z1-Z1 ′ of the optical head shown in FIG. FIG. 3 is a perspective sectional view of a part M shown in FIG. 2. It is explanatory drawing which shows the manufacturing process of 1 A of optical heads. FIG. 6 is a plan view of an electro-optical device according to a second embodiment of the invention. It is a top view of the optical head which concerns on 3rd Embodiment of this invention. FIG. 7 is a sectional view taken along the line Z2-Z2 ′ of the optical head shown in FIG. 6. FIG. 8 is a perspective sectional view of a portion M ′ shown in FIG. 7. It is explanatory drawing which shows the manufacturing process of the optical head 1B. FIG. 10 is a plan view of an electro-optical device according to a fourth embodiment of the invention. FIG. 10 is a perspective view of a personal computer that is an electronic apparatus to which the electro-optical device according to the second and fourth embodiments is applied. It is sectional drawing which shows the structural example of the conventional light emitting element.

Explanation of symbols

1A, 1B, 2A, 2B ... electro-optical device, 10, 110 ... substrate, 11, 111 ... anode (
Pixel electrode), 12, 112 ... lyophilic insulating film, 13 ... lyophobic layer, 20, 120 ... hole injection layer,
21, 121... Light emitting layer (organic semiconductor layer), 30, 130... Cathode, 50B.
0A, 60A ... common bank, 61A ... individual bank, P ... light emitting element.

Claims (15)

A substrate on which a plurality of pixel electrodes are formed;
A lyophilic layer formed on the substrate;
A liquid repellent layer formed on the lyophilic layer;
A plurality of pixel openings provided corresponding to each of the plurality of pixel electrodes and formed in the lyophilic layer and the liquid repellent layer;
A common bank surrounding the plurality of pixel openings,
The lyophilic layer has a strong affinity for liquid compared to the liquid repellent layer,
An electro-optical device. An injection layer for injecting electrons or holes provided on the pixel electrode located in the pixel opening;
An organic semiconductor layer continuously formed inside the common bank;
The electro-optical device according to claim 1, further comprising: 3. The electro-optical device according to claim 1, wherein the pixel openings have substantially the same shape in plan view in the lyophilic layer and the liquid repellent layer. 4. The electro-optical device according to claim 1, wherein the liquid repellent layer has a planar shape in which holes of the plurality of pixel openings are opened. 5. 4. The electro-optical device according to claim 1, wherein the liquid repellent layer is formed as an individual bank surrounding the periphery of the pixel opening in each of the plurality of pixel openings. 5. apparatus. A plurality of the common banks are formed,
6. The electro-optical device according to claim 1, wherein the organic semiconductor layer formed in each of the plurality of common banks emits light in a single color. 7. The common bank has a stronger non-affinity for a liquid repellent layer forming material liquid for forming the organic semiconductor layer than the liquid repellent layer. The electro-optical device according to Item. The electro-optical device according to claim 7, wherein the common bank is made of a fluorinated resin. The electro-optical device according to claim 1, wherein the lyophilic layer is made of an inorganic material. The electro-optical device according to claim 9, wherein the inorganic material includes silicon oxide, silicon nitride, or silicon oxynitride. The liquid repellent layer and the common bank are made of an organic material.
The electro-optical device according to any one of 0. Forming a lyophilic layer on a substrate on which a plurality of pixel electrodes are formed;
Forming a liquid repellent layer having a plurality of openings corresponding to each of the plurality of pixel electrodes on the lyophilic layer;
Forming a common bank including the plurality of openings inside on the liquid repellent layer;
Etching the lyophilic layer using at least the lyophobic layer as an etching mask to form a pixel opening exposing the pixel electrode;
Forming an injection layer for injecting electrons or holes on the pixel electrode of the pixel opening;
Forming an organic semiconductor layer inside the common bank;
A method of manufacturing an electro-optical device comprising: 13. The method of manufacturing an electro-optical device according to claim 12, wherein the lyophilic layer is etched by a plasma etching method. The step of forming the injection layer fills the pixel opening with an injection layer forming material liquid for forming the injection layer by an inkjet method.
A method for manufacturing the electro-optical device according to claim 3. 15. The step of forming the organic semiconductor layer, wherein an organic semiconductor layer forming material liquid for forming the organic semiconductor layer is filled inside the common bank by an inkjet method. A method for manufacturing the electro-optical device according to claim 1.

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