JP2011090925A - Method for manufacturing electro-optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an electro-optical device high in display quality and suitably applicable to a large-sized display device. <P>SOLUTION: The manufacturing method includes forming barrier ribs 7a, 7b to expose a portion of cathode wiring 32 and then forming an organic EL layer 8 covering the barrier ribs and the cathode wiring 32. In this state, laser beams are radiated toward a light heat converting layer 31. The light heat-converting layer 31 and the cathode wiring 32 thereby generate heat, and the organic EL layer 8 at a portion abutting on the cathode wiring is sublimated and removed. A common electrode 9 is then formed by a vacuum deposition method, and the common electrode 9 is formed also at the exposed portion in the cathode wiring 32. Consequently, even if the surface resistance of the common electrode 9 is high, periodic connection by the cathode wiring 32 is secured within a display region V to suppress the degradation of emission luminance. Further, since a vapor deposition mask is not used in this manufacturing method, the method can be suitably applied to the manufacture of the large-sized display device. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an electro-optical device.

As a configuration (production method) of a display device using a low molecular organic EL (Electro Luminescence) element, two methods are known. One is a so-called “RGB coating method” in which red, green, and blue color elements are separately painted for each pixel using a vapor deposition mask to form red, green, and blue color pixels. The other is that without forming a vapor deposition mask, a white element is formed on the entire surface, and each color filter of red, green, and blue is arranged thereon, thereby forming each color pixel of RGB. It is.
For example, when manufacturing a large-screen display device such as a large television, the “white light emission + color filter method” is said to be more suitable. This is because when a large display device is manufactured by the “RGB color separation method”, the dimensional accuracy deteriorates, thermal expansion, deflection due to the weight of the mask, etc. occurs as the deposition mask becomes larger. This is because it is difficult to ensure.

Further, as an element configuration, in any of the above-described methods, a top emission type that can take a larger pixel aperture ratio than a bottom emission type has become mainstream.
Here, when the top emission type display device is configured by “white light emission + color filter method”, there is a problem that the light emission luminance at the center of the screen is lower than that at the peripheral portion. This is because in the case of the top emission type, light is extracted from the cathode side that is commonly formed in each pixel, and thus it is necessary to increase the transparency of the common cathode. Specifically, the common cathode is configured to be thin because of the need to increase transparency, and the resistance becomes higher as the thickness becomes thinner.
With respect to this problem, Patent Document 1 discloses that the auxiliary wiring having a low resistance value is periodically formed in the upper layer or the lower layer of the cathode by a vacuum deposition method or a sputtering method, thereby reducing the resistance value of the cathode. It can be solved.

Japanese Patent Laid-Open No. 2001-230086

However, in the conventional manufacturing method, it is necessary to perform a vapor deposition method using a vapor deposition mask for forming the periodic auxiliary wiring, and thus there is a problem that it is difficult to apply to the production of a large display device. . Specifically, Patent Document 1 does not include a description of using a vapor deposition mask, but the auxiliary wiring shown in a lattice shape or a stripe shape in a plan view is vacuum deposited or sputtered on the upper layer or lower layer of the cathode. This is because a vapor deposition mask is required according to a known technique.
That is, since the conventional manufacturing method includes a step of forming auxiliary wiring using a vapor deposition mask, it is difficult to apply to a large display device.
In addition, when using a vapor deposition mask, it is necessary to adhere the vapor deposition mask to the element substrate. Therefore, when the mask is removed after vapor deposition, a part of the organic layer adheres to the mask and causes display defects. , Which was a factor in yield reduction.
That is, the conventional manufacturing method has a problem that the yield is low.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples or forms.

(Application example)
A method of manufacturing an electro-optical device having a plurality of pixels, the step of forming a pixel electrode serving as an opening of a pixel on a substrate, and a photothermal conversion layer in a gap portion between the pixel electrode and an adjacent pixel electrode A step of forming, a step of forming a cathode wiring overlying the photothermal conversion layer, a step of exposing a part of the cathode wiring to form a partition partitioning a plurality of pixel electrodes, and a vapor deposition method. A process of forming an organic thin film layer covering the electrodes and the partition walls, a step of irradiating a laser beam from the substrate side toward the photothermal conversion layer, and an organic vapor deposition method to cover the organic thin film layer and to transmit light. A method for manufacturing an electro-optical device, comprising: forming a common cathode having a structure, wherein the cathode wiring and the common cathode are electrically connected through an exposed portion of the cathode wiring.

According to this method of manufacturing an electro-optical device, after the partition is formed so that a part of the cathode wiring is exposed, the organic thin film layer is formed to cover the partition. In this state, by irradiating the light-to-heat conversion layer with laser light from the substrate side, the light-to-heat conversion layer and the upper layer cathode wiring generate heat, and the organic thin film layer in contact with the cathode wiring is sublimated. Will be removed.
In this state, since the common cathode having light transmittance is formed by the vapor deposition method, the common cathode is also formed in the exposed portion of the cathode wiring. That is, the common cathode is formed in a state where the cathode wiring and the common cathode are electrically connected through the exposed portion.
Therefore, even if the surface resistance of the thinned common electrode is increased, the periodic connection by the cathode wiring is ensured in the display area, so that the decrease in the emission luminance near the center of the display area is suppressed. Can do.
Therefore, a display device with high display quality can be provided.

Furthermore, since the electro-optical device manufacturing method according to the application example includes a combination of a plurality of photolithographic steps, a simple vapor deposition step, and a laser irradiation step, the method includes a step of using a vapor deposition mask. Unlike the conventional manufacturing method in which it is difficult to ensure the separation accuracy, it can be suitably applied to the manufacture of a large display device.
Accordingly, it is possible to provide a method of manufacturing an electro-optical device that can be suitably applied to a large display device.
In addition, since a process using a vapor deposition mask that induces display defects is not included, yield can be improved.
Accordingly, it is possible to provide a method for manufacturing an electro-optical device with a high yield.

The pixel electrode is preferably made of a transparent electrode, and preferably further includes a step of forming a reflective layer overlapping the pixel electrode before the step of forming the pixel electrode.
Further, the cathode wiring is connected to the cathode trunk line formed on the substrate, and the laminated wiring portion including the photothermal conversion layer and the cathode wiring has a stripe shape, a lattice shape, or a plurality of portions in plan view. It is preferable that each pixel is formed in an island shape.
The photothermal conversion layer is made of molybdenum, titanium, or chromium, or an alloy containing at least one of these, and the cathode wiring is made of aluminum, gold, copper, or these Among these, it is preferable that it is made of an alloy containing at least one kind.

In addition, the laser beam includes an infrared ray having a wavelength of 800 nm, and the irradiation intensity and irradiation time that can give the photothermal conversion layer the amount of heat necessary to sublimate the organic thin film layer that contacts the exposed portion of the cathode wiring. Irradiation is preferred.
In the partition formation step, it is preferable that a partition made of a substantially black resin is formed using a photolithography method, and the exposed portion of the cathode wiring is located at the bottom of the groove formed in the partition.
Further, in the organic thin film layer forming step, an organic thin film layer comprising a plurality of layers including a light emitting layer that emits substantially white light is formed. After the common cathode forming step, the cathode protective layer forming step and the substrate are opposed to each other. The counter substrate is provided with color filters for each color including red, blue, and green corresponding to each pixel, and the light emitted from the pixel corresponds to the counter substrate. It is preferable that the color light is transmitted and selected by the color filter and emitted from the counter substrate.

  A method for manufacturing an electro-optical device having a plurality of pixels, the step of forming a cathode wiring with the same material as the reflecting layer and the reflecting layer on the substrate, and an opening of the pixel on the upper layer side of the reflecting layer A step of forming a light-transmissive pixel electrode, a step of forming a photothermal conversion layer on an upper layer of the cathode wiring, a step of exposing a part of the cathode wiring and forming a partition partitioning a plurality of pixel electrodes, A process of forming an organic thin film layer by covering the pixel electrode and the partition using the vapor deposition method, a step of irradiating laser light from the organic thin film layer side toward the photothermal conversion layer, and an organic method using the vapor deposition method A step of covering the thin film layer and forming a light-transmitting common cathode, wherein the cathode wiring and the common cathode are electrically connected via an exposed portion of the cathode wiring; Manufacturing method of electro-optical device.

A method of manufacturing an electro-optical device having a plurality of pixels, the step of forming a pixel electrode serving as an opening of a pixel on a substrate, and the formation of a cathode wiring in a gap portion between the pixel electrode and an adjacent pixel electrode A step of exposing a part of the cathode wiring to form a partition for partitioning the plurality of pixel electrodes, and a step of forming an organic thin film layer covering the pixel electrode and the partition using a vapor deposition method. A step of irradiating laser light from the substrate side or the organic thin film layer side toward the cathode wiring, and a step of forming a light-transmitting common cathode by covering the organic thin film layer using a vapor deposition method And the common cathode is electrically connected to the cathode wiring composed of the photothermal conversion material that generates heat upon irradiation with the laser beam through the exposed portion of the cathode wiring. Device manufacturing method.
The cathode wiring is preferably made of molybdenum or an alloy containing molybdenum.

FIG. 3 is a perspective view illustrating one embodiment of a display device according to Embodiment 1. The sectional side view in the pp cross section of FIG. (A) The top view of an element substrate, (b) is a sectional side view in the qq cross section of (a). The flowchart figure which shows the manufacturing process of a display panel. The figure which shows the one aspect | mode in a (a)-(c) manufacturing process. (A), (b) The figure which shows the one aspect | mode in a manufacturing process. (A) The top view of the element substrate which concerns on Embodiment 2, (b) is sectional drawing of the ss cross section in (a). The figure which shows the one aspect | mode in a (a)-(c) manufacturing process. (A), (b) The figure which shows the one aspect | mode in a manufacturing process. FIG. 5 is a side sectional view of an element substrate according to a third embodiment. The perspective view which shows the large sized television as an electronic device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the scale of each layer and each part is different from the actual scale so that each layer and each part can be recognized on the drawing.

(Embodiment 1)
"Overview of display device"
FIG. 1 is a perspective view showing an aspect of the display device according to the present embodiment.
First, an outline of the display device 100 as an electro-optical device according to Embodiment 1 of the present invention will be described.

The display device 100 is an organic EL display device, and includes a display panel 18, a flexible substrate 20, and the like. The display panel 18 is a top emission type organic EL display panel in which a functional layer including a light emitting layer is sandwiched between the element substrate 1 and the counter substrate 17, and emits display light from the counter substrate 17 side.
The display panel 18 includes a display region V composed of a plurality of pixels arranged in a matrix. As enlarged and shown in the upper right of FIG. 1, red (R), green (G), and blue (B) color pixels are periodically arranged in the display area V, and each pixel emits display. A full color image is displayed by light. Each pixel is a light-emitting pixel, but is called a pixel. Further, the display panel is not limited to a color display panel, and may be a top emission type organic EL display panel. For example, a display panel for monochrome display may be used.
The display area V has a vertically long rectangle. In each drawing including FIG. 1, the vertical direction is defined as the Y-axis direction, and the horizontal direction shorter than the vertical direction is defined as the X-axis direction. The thickness direction of the display panel 18 is the Z-axis direction. Further, the Y-axis (+) and (−) directions are defined as the vertical direction, and the X-axis (+) and (−) directions are defined as the horizontal direction.

As will be described in detail later, the display device 100 forms a plurality of pixels that emit substantially white light on the element substrate 1 side, and arranges each color filter of red, green, and blue on the counter substrate 17 side, whereby each color pixel of RGB This is a top emission type organic EL display panel by “white light emission + color filter system”. In addition, a common cathode (common electrode) having light transparency is formed in common to a plurality of pixels that emit substantially white light so as to cover each pixel.
Conventionally, when a top emission type display device is configured by “white light emission + color filter method”, it is necessary to form an auxiliary (cathode) wiring for lowering the resistance value of the common electrode by using a vapor deposition mask. Therefore, application to a large display device has been difficult.
On the other hand, according to the manufacturing method of the display device 100, the cathode (auxiliary) wiring can be formed without using the vapor deposition mask, and therefore, the method can be suitably applied to a large display device. Furthermore, since the occurrence of defects due to the evaporation mask is suppressed, the yield can be improved.

In the display panel 18, a flexible substrate 20 is connected to an extended region where the element substrate 1 extends from the counter substrate 17. The flexible board is an abbreviation for a flexible printed circuit board having flexibility in which an iron foil wiring or the like is formed on a polyimide film base. In addition, a driving IC (Integrated Circuit) 21 is mounted on the flexible substrate 20, and a plurality of terminals for connection to a dedicated controller or an external device (none of which are shown) are formed at the end thereof. Has been.
The display panel 18 displays images, characters, and the like in the display region V by receiving control signals including power and image signals from an external device via the flexible substrate 20.

"Detailed configuration of the display panel"
FIG. 2 is a sectional side view taken along the line pp of FIG.
Next, a detailed configuration of the display panel 18 will be described.
The display panel 18 includes an element substrate 1, an element layer 2, a planarizing layer 4, a reflective layer 5, a pixel electrode 6, a partition wall 7, an organic EL layer 8 as an electro-optic layer, a common electrode 9, an electrode protective layer 10, and a buffer layer. 11, a gas barrier layer 12, a filler 13, a CF layer 14, a counter substrate 17, and the like. A portion sandwiched between the element substrate 1 and the counter substrate 17 is referred to as a functional layer 16. In other words, the laminated structure from the element layer 2 to the CF layer 14 is referred to as a functional layer 16.
The element substrate 1 is made of inorganic glass. In this embodiment, alkali-free glass is used as a suitable example. In addition, it is not limited to this structure, You may use a resin substrate. Further, since it is a top emission type, a material having low light transmittance may be used, and for example, a configuration using a metal substrate may be used.
In the element layer 2, a pixel circuit for actively driving each pixel is formed. The pixel circuit includes a selection transistor for selecting a pixel made of a TFT (Thin Film Transistor), a driving transistor 3 for flowing a current to the organic EL layer 8, and the like, which are formed corresponding to each pixel. Has been. The pixel circuit uses low-temperature polysilicon as the active layer as a preferred example, but may have a configuration using amorphous silicon as the active layer.

In the upper layer (Z-axis (−) direction) of the element layer 2, for example, a planarization layer 4 that is an insulating layer made of an acrylic resin or the like is formed.
The reflective layer 5 and the pixel electrode 6 are laminated in this order on the flattening layer 4 so as to be divided for each pixel.
The reflection layer 5 is a reflection layer made of, for example, aluminum, and reflects light traveling from the organic EL layer 8 toward the element substrate 1 to make light that contributes to display.
The pixel electrode 6 is composed of a transparent electrode such as ITO (Indium Tin Oxide) or ZnO, and is connected to a drain terminal of the driving transistor 3 of the element layer 2 and a contact hole penetrating the planarization layer 4 for each pixel. ing. In the present embodiment, as a preferred example, an insulating layer 25 made of a transparent inorganic material such as SiO ₂ is interposed between the reflective layer 5 and the pixel electrode 6. However, the present invention is not limited to this configuration. However, any structure that functions as a reflective electrode may be used. For example, the reflective layer 5 may be omitted, and only the pixel electrode 6 may be formed of a reflective material such as aluminum. Alternatively, the pixel electrode 6 may be formed directly on the reflective layer 5 without interposing an inorganic insulating layer.

The partition wall 7 is made of a photocurable black resin or the like, and partitions each pixel in a lattice shape in a plane. Note that the pixel circuit including the driving transistor 3 in the element layer 2 is disposed so as to overlap the partition in a planar manner in order to prevent malfunction due to light.
The organic EL layer 8 is formed so as to cover the pixel electrode 6 and the partition wall 7. In FIG. 2, the structure is a single layer. Actually, each layer is composed of a hole transport layer, a light emitting layer, an electron injection layer, and the like made of an organic thin film. Are stacked. The hole transport layer is made of a sublimable material such as aromatic diamine (TPAB2Me-TPD, α-NPD). The light emitting layer is composed of an organic light emitting material thin film composed of a multilayer that emits substantially white light formed by combining three colors of red, green, and blue. The electron injection layer is made of LiF (lithium fluoride) or the like.

The common electrode 9 as a common cathode is a metal thin film layer in which a metal such as MgAg is formed very thin so as to transmit light, and is formed so as to cover the organic EL layer 8 across all pixels. In addition, since light is emitted through the layer, the thickness thereof is extremely thin, for example, 10 nm to 20 nm in order to improve light transmittance.
For this reason, the resistance value per unit area of the common electrode 9, in other words, the surface resistance increases, and the voltage drop increases as the distance from the connecting portion with the cathode trunk line wired in the element layer 2 increases. In the case where the cathode (auxiliary) wiring described later is not provided, there is a problem that the light emission luminance near the center of the display region V is lowered.
For this reason, the common electrode 9 and the cathode trunk line are periodically connected to each other by the cathode (auxiliary) wiring 32 (FIG. 3) described later in the display region V in addition to the connection by the contact hole 9c in the peripheral portion of the display region V. The connection is secured. The contact hole 9c is connected to a cathode trunk for applying a cathode potential wired in the element layer 2.
Alternatively, a cathode branch made of a material having excellent conductivity such as aluminum may be formed on the planarization layer 4 through the contact hole 9c, and the cathode branch and the common electrode 9 may be connected. Alternatively, a plurality of contact holes 9 c may be provided at substantially equal intervals in the peripheral portion of the display region V, and these may be connected to the common electrode 9.

The electrode protective layer 10 is made of a high-density and highly transparent material such as SiO ₂ , Si ₃ N ₄ , or SiOxNy, and the organic EL layer 8 is formed by covering the common electrode 9. Prevents moisture from entering the water.
The buffer layer 11 is a transparent organic buffer layer such as a thermosetting epoxy resin.
The gas barrier layer 12 is a gas barrier layer made of the same material as the electrode protective layer 10, and is formed so as to further cover the buffer layer 11, so that moisture and the like enter the internal laminated structure including the organic EL layer 8. Is preventing.
The filler 13 is a transparent adhesive layer made of, for example, a thermosetting epoxy resin, and fills the uneven surface between the gas barrier layer 12 and the CF layer 14 and bonds them together. The display panel 18 also functions to prevent moisture and the like from entering the internal laminated structure including the organic EL layer 8 from the peripheral edge of the display panel 18.

The counter substrate 17 is made of transparent inorganic glass, and non-alkali glass is used as a suitable example. Further, the CF layer 14 is formed on the organic EL layer 8 side (Z-axis (+) side) of the counter substrate 17.
In the CF layer 14, a red color filter 14r, a green color filter 14g, and a blue color filter 14b are arranged similarly to the pixel arrangement. Specifically, the color filters of each color are arranged so as to overlap with the corresponding pixel electrodes 6, and light shielding portions indicated by hatching are formed between the color filters. The light shielding portion is formed in a lattice shape so as to overlap the partition wall 7 in a plan view, and optically functions as a black matrix.
The counter substrate 17 and the element substrate 1 are bonded and sealed with a sealant 15 formed on the peripheral edge of the counter substrate 17. As the sealant 15, an epoxy adhesive, an ultraviolet curable resin, or the like is used.

From each pixel configured in this manner, display light corresponding to the color tone of the color filter is emitted. For example, in the case of a red pixel, the white light emitted from the organic EL layer 8 is selected by the red color filter 14r and emitted from the counter substrate 17 as red display light. The same applies to green and blue pixels.
Thereby, in the display area V, a full-color image is displayed by display light from the plurality of color pixels emitted from the counter substrate 17.

"Cathode layout"
FIG. 3A is a plan view of the element substrate 1, and FIG. 3B is a side sectional view of the qq section of FIG.
Here, the layout, material, and the like of the cathode wiring 32 formed to make the surface resistance of the common electrode 9 uniform will be described.
FIG. 3A is a plan view of the element substrate 1 in a state where up to the electrode protective layer 10 is formed. In addition, since the cathode wiring 32 is arrange | positioned in the lower layer of the partition 7 which consists of black resin, although it is not observed actually, in the figure, the cathode wiring 32 is shown as a permeation | transmission figure.
As shown in the figure, each pixel is divided in a grid pattern by partition walls 7, and an elliptical pixel electrode 6 that is long in the Y-axis direction is arranged in each divided pixel. In other words, a plurality of pixels are arranged in a matrix form in a matrix. The planar shape of the pixel electrode 6 is not limited to an elliptical shape, and may be a track shape, a rectangle, or a circle.

Here, when the pixel array in the X-axis direction is a pixel row and the pixel array in the Y-axis direction is a pixel column, the cathode wiring 32 extends in the X-axis direction every two pixel rows. Yes. Specifically, it is formed along the extending direction of the partition wall in the lower layer of the partition wall 7 positioned every two pixel rows.
Further, the left and right end portions of the cathode wiring 32 extend to the peripheral portion of the display region V, and at least one end portion is connected to the contact hole 9c or the cathode branch line.
As described above, in the preferred example, the cathode wiring 32 is described as being arranged in a horizontal stripe shape for every two pixel rows. However, the present invention is not limited to this layout, and it depends on the surface resistance value of the common electrode 9. It is preferable to determine appropriately. For example, the cathode wirings 32 may be arranged in a vertical stripe shape, or may be arranged in a lattice shape along the partition wall 7.

FIG. 3B is a side sectional view of the qq section of FIG. 3A and shows a state where one pixel is cut along the longitudinal direction (Y-axis direction).
In the drawing, the cathode wiring 32 is formed on the partition walls 7a and 7b shown on the left side, and the cathode wiring 32 is not formed on the partition wall 7 shown on the right side. The right partition 7 has a trapezoidal shape in which the lower bottom is long and the top bottom is short, similar to the partition of FIG. 2 in which pixels are cut along the short direction (X-axis direction).
The left partition walls 7a and 7b have a form in which the partition wall 7 is divided into two partition walls 7a and 7b by forming a V-shaped groove at substantially the center of the upper bottom of the right partition wall 7. In other words, the two partition walls 7a and 7b are formed so that a V-shaped groove is formed between them.
A cathode wiring 32 is formed at the bottom of the V-shaped groove. A photothermal conversion layer 31 is formed under the cathode wiring 32.

By arranging these positional relationships, the photothermal conversion layer 31 and the cathode wiring 32 are laminated in this order on the planarizing layer 4, and a part of the wiring is exposed on the cathode wiring 32. In addition, two trapezoidal partition walls 7a and 7b are formed.
The exposed portion of the cathode wiring 32 is located at the bottom of a V-shaped groove formed between the two partition walls 7a and 7b. In other words, the exposed portion of the cathode wiring 32 is located at the bottom of the groove formed in the partition wall composed of the two partition walls 7a and 7b.
Here, a part of the common electrode 9 formed so as to cover the organic EL layer 8 is in contact with the exposed portion of the cathode wiring 32. In other words, since the organic EL layer 8 is divided at the bottom of the V-shaped groove, the exposed portion of the cathode wiring 32 and the common electrode 9 are connected.
That is, the connection between the common electrode 9 and the cathode trunk line (branch line) is ensured by the cathode wiring 32 even in the display region V.

A detailed manufacturing method including the step of dividing the organic EL layer 8 at the bottom of the V-shaped groove will be described later.
The photothermal conversion layer 31 is preferably made of chromium, a chromium oxide film, a chromium nitride film, or an alloy containing chromium. Note that the material is not limited to these, and any material that generates heat upon irradiation with infrared rays may be used. For example, molybdenum, titanium, or an alloy containing at least one of them may be used.
The cathode wiring 32 is preferably made of aluminum or an alloy containing aluminum. Note that the material is not limited to these, and any material having high conductivity may be used. Gold, copper, or an alloy containing at least one of them may be used.

"Manufacturing method of display panel"
FIG. 4 is a flowchart showing the manufacturing process of the display panel. FIG. 5A to FIG. 5C are diagrams showing an embodiment in the manufacturing process. 6 (a) and 6 (b) are diagrams showing an embodiment in the manufacturing process.
Here, the manufacturing method of the display panel 18 will be described focusing on the process from the photothermal conversion layer 31 and the cathode wiring 32 to the common electrode 9 formation process.

First, the element substrate 1 in which the flattening layer 4 is formed is formed by using a known manufacturing method such as a photolithography method, a vapor deposition method, a CVD (Chemical Vapor Deposition) method or the like.
In step S1, the reflective layer 5 made of aluminum is formed by vapor deposition, sputtering, or photolithography. Subsequently, the insulating layer 25 is formed so as to cover the reflective layer 5 by using the CVD method and the photolithography method. In a preferred example, SiO ₂ is used as the insulating layer 25.
In step S2, the pixel electrode 6 made of ITO is formed on the insulating layer 25 using a sputtering method and a photolithography method.
In step S3, the photothermal conversion layer 31 made of chromium is formed using a sputtering method and a photolithography method. The thickness of the photothermal conversion layer 31 in the preferred example was about 200 nm. In addition, it is not limited to this thickness, What is necessary is just in the range of 100 nm-400 nm.

In step S4, the cathode wiring 32 made of aluminum is formed on the photothermal conversion layer 31 by vapor deposition, sputtering, or photolithography.
In step S5, a lattice-like partition wall 7 is formed by using a photolithography method. Specifically, a photocurable resin is applied to the entire surface of the element substrate 1 by a spin coat method or the like, and then exposed and developed using a lattice-like mask to form lattice-like partition walls 7. In the preferred example, a black photocurable resin is used.
Thereby, as shown in FIG. 3A, a grid-like partition wall 7 is formed to partition the plurality of pixel electrodes 6 one by one. FIG. 5A is an enlarged side sectional view of the partition wall on the side where the cathode wiring 32 is formed in the qq section in FIG. In other words, it is an enlarged view of the left partition walls 7a and 7b in FIG. As shown in the drawing, the two trapezoidal partition walls 7a and 7b are formed such that a part of the cathode wiring 32 is exposed at the bottom of a V-shaped groove formed between them.

In step S6, an organic EL layer 8 is formed by depositing an organic light emitting material so as to cover the partition walls 7a and 7b, the cathode wiring 32, and the pixel electrode 6 by using a vacuum deposition method. The organic EL layer 8 is formed by laminating a plurality of organic thin film layers such as a hole transport layer and a light emitting layer.
This state is shown in FIG. 5B, and the organic EL layer 8 is formed on the entire surface covering the partition walls 7 a and 7 b and the cathode wiring 32.
In step S7, laser light is irradiated from the element substrate 1 side toward the photothermal conversion layer 31 as indicated by an arrow in FIG. As a preferred example, the photothermal conversion layer 31 is irradiated with an infrared laser beam having an energy density of about 2.6 × 10 ⁻³ mJ / μm ² and a wavelength of about 800 nm. As a result, the photothermal conversion layer 31 is heated, the heat is propagated to the upper cathode wiring 32, and the portion of the organic EL layer 8 facing the cathode wiring 32 is sublimated. The laser beam is not limited to the above-mentioned conditions, and any laser beam having an energy amount capable of sublimating the portion of the organic EL layer 8 facing the cathode wiring 32 may be used, and has a wavelength of at least about 800 nm. The laser beam is preferably included. In other words, any irradiation intensity and irradiation time can be used as long as the amount of heat necessary to sublimate the organic EL layer 8 in contact with the exposed portion of the cathode wiring 32 can be given to the photothermal conversion layer 31. FIG. 5C shows the state of the organic EL layer 8 after laser light irradiation. The portion of the organic EL layer 8 facing the cathode wiring 32 is sublimated, and a part of the cathode wiring 32 is exposed. It has become a state.

In step S <b> 8, the common electrode 9 made of MgAg is formed by covering the exposed portion of the organic EL layer 8 and the cathode wiring 32 by vacuum deposition. As a result, as shown in FIG. 6A, the common electrode 9 that covers the organic EL layer 8 and is partially connected to the cathode wiring 32 is formed.
In step S9, the electrode protection layer 10 made of SiO ₂ is formed by covering the common electrode 9 by the CVD method. This state is shown in FIG.
In addition, each process is performed in the pressure-reduced environment filled with the inert gas from the organic EL layer 8 formation process of step S6 to the common electrode 9 formation process of step S8. In other words, the device setting is such that the element substrate 1 can move between the chambers so that the organic EL layer 8 is not exposed to the air environment. As a result, the desired light emission characteristics of the organic EL layer 8 can be maintained.

Further, following step S9, a buffer layer 11 made of a thermosetting epoxy resin, a gas barrier layer 12 made of SiO ₂ or the like is formed by using a spin coat method, a CVD method, or the like, as shown in FIG. Thus, the element substrate 1 is completed.
Then, the display substrate 18 is completed by bonding the element substrate 1 having the laminated structure and the separately manufactured counter substrate 17 together with the filler 13 or the sealant 15.

As described above, according to the display device 100 and the manufacturing method according to the present embodiment, the following effects can be obtained.
According to the method for manufacturing the display device 100, after the partition walls 7a and 7b are formed so that a part of the cathode wiring 32 is exposed, the organic EL layer 8 is formed covering the partition walls and the cathode wiring 32. In this state, by irradiating laser light toward the photothermal conversion layer 31 from the element substrate 1 side, the photothermal conversion layer 31 and the upper-layer cathode wiring 32 generate heat and are in contact with the cathode wiring The organic EL layer 8 is sublimated and removed.
Then, since the common electrode 9 is formed by the vacuum evaporation method in a state where the portion of the organic EL layer 8 facing the cathode wiring 32 is removed, the common electrode 9 is also formed on the exposed portion of the cathode wiring 32. Will be. That is, the common electrode 9 is formed in a state where the cathode wiring 32 and the common electrode 9 are electrically connected via the exposed portion.
Therefore, even if the surface resistance of the thinned common electrode 9 is increased, the periodic connection by the cathode wiring 32 is ensured in the display region V, so that the emission luminance is reduced near the center of the display region V. Can be suppressed.
Therefore, the display device 100 with high display quality can be provided.

Further, the manufacturing method of the display device 100 includes a process combining a plurality of photolithography processes, a simple vapor deposition process, and a laser irradiation process, and therefore includes a process using a vapor deposition mask, and ensures coating accuracy. Unlike the conventional manufacturing method, which is difficult, the method can be suitably applied to manufacturing a large display device. In other words, since the manufacturing method of the display device 100 does not include a step of using a vapor deposition mask, it can be suitably applied to manufacturing a large display device.
Therefore, it is possible to provide a method for manufacturing the display device 100 that can be suitably applied to a large display device.

Further, since a process using a vapor deposition mask that induces display defects is not included, yield can be improved.
Therefore, a method for manufacturing the display device 100 with a high yield can be provided.

(Embodiment 2)
FIG. 7A is a plan view of the element substrate according to the second embodiment, and corresponds to FIG. FIG. 7B is a cross-sectional view taken along the line ss in FIG. 7A and corresponds to FIG. FIGS. 8A to 8C are diagrams showing an embodiment in the manufacturing process, and correspond to FIG. FIGS. 9A and 9B are diagrams showing an embodiment in the manufacturing process and correspond to FIG.
The display device according to Embodiment 2 of the present invention will be described below. In addition, about the component same as Embodiment 1, the same number is attached | subjected and the overlapping description is abbreviate | omitted.
The display device of the present embodiment includes an element substrate 1b having a configuration different from that of the element substrate 1 of the first embodiment. Specifically, the stacking order of the cathode wiring and the photothermal conversion layer is reversed, and the planar layout is different from the element substrate 1 of the first embodiment. Also, some of the manufacturing methods are different. Other than that, it is substantially the same as the description in the first embodiment. The element substrate 1b refers to the entire multilayer structure formed on the element substrate 1 in the present embodiment.

As shown in FIG. 7B, the cathode wiring 5b and the photothermal conversion layer 31 are laminated in this order from the element substrate 1 side at the bottom of the V-shaped groove between the two partition walls 7a and 7b. The exposed portion of the photothermal conversion layer 31 and the common electrode 9 are connected. Here, the cathode wiring 5b is a wiring made of aluminum formed in the same process as the reflective layer 5, and is connected to the cathode main line through a contact hole 9c.
That is, the stacking order of the photothermal conversion layer and the cathode wiring is reversed as compared with the configuration of FIG. 3, and the cathode wiring 5b and the photothermal conversion layer 31 are stacked in this order from the element substrate 1 side.
Then, as shown in FIG. 7A, the laminated portion of the cathode wiring 5b and the light-to-heat conversion layer 31 is arranged in an island shape at a ratio of approximately one for every four pixels in a plan view. Each of the stacked portions arranged in an island shape is connected to the cathode main line by a contact hole. In addition, it is not limited to the structure arrange | positioned at a ratio of about 1 to about 4 pixels, According to the surface resistance value (specification) of the common electrode 9, the number of formation is suitably set so that an expected electrical conductivity can be ensured. You just have to decide.

Next, with reference to FIG. 4, the element substrate manufacturing method according to the second embodiment will be described focusing on differences from the first embodiment.
First, in the flowchart of FIG. 4, steps S1, S3, and S7 are changed, and step S4 is not necessary.
Specifically, in step S1, the reflective layer 5 made of aluminum and the cathode wiring 5b are formed by vapor deposition, sputtering, or photolithography. In other words, the cathode wiring 5 b is also formed in the same process as the reflective layer 5.
In step S3, the photothermal conversion layer 31 made of chromium is formed on the cathode wiring 5b by using a sputtering method and a photolithography method.
Moreover, since the cathode wiring 5b is formed in step S1, step S4 becomes unnecessary.
In step S5, a lattice-like partition wall 7 is formed by using a photolithography method. This state is shown in FIG.

In step S <b> 6, an organic light-emitting material is vapor-deposited so as to cover the partition walls 7 a and 7 b, the photothermal conversion layer 31, and the pixel electrode 6 by using a vacuum evaporation method, thereby forming the organic EL layer 8.
In step S7, laser light is irradiated from the organic EL layer 8 side (Z-axis (−) side) toward the photothermal conversion layer 31 as indicated by the arrow in FIG. Thus, in the second embodiment, the direction of laser light irradiation is from the opposite side of the first embodiment.
Thereby, the photothermal conversion layer 31 is heated, and the organic EL layer 8 of the portion facing the layer is sublimated by the heat.
FIG. 8C shows the state of the organic EL layer 8 after laser light irradiation. The portion of the organic EL layer 8 facing the photothermal conversion layer 31 is sublimated, and a part of the photothermal conversion layer 31 is exposed. It has become a state.

In step S8, the common electrode 9 made of MgAg is formed by vacuum evaporation to cover the exposed portions of the organic EL layer 8 and the photothermal conversion layer 31. As a result, as shown in FIG. 9A, the common electrode 9 that covers the organic EL layer 8 and is partially connected to the photothermal conversion layer 31 is formed.
In step S9, the electrode protection layer 10 made of SiO ₂ is formed by covering the common electrode 9 by the CVD method. This state is shown in FIG.
Other manufacturing steps are the same as the manufacturing method in the first embodiment.

As described above, according to the present embodiment, in addition to the effects in the first embodiment, the following effects can be obtained.
As shown in FIG. 7A, the stacked portions of the cathode wiring 5b and the photothermal conversion layer 31 are arranged in an island shape in a ratio of approximately one for every four pixels in plan view. That is, even if the surface resistance of the thinned common electrode 9 is increased, the periodic connection by the cathode wiring 5b is ensured in the display region V, so that the emission luminance in the vicinity of the central portion of the display region V is reduced. Can be suppressed.
Therefore, a display device with high display quality can be provided.
Moreover, since the laminated part which consists of the cathode wiring 5b and the photothermal conversion layer 31 becomes the structure which backed the photothermal conversion layer 31 which consists of chromium with the aluminum wiring (cathode wiring 5b), the resistance value as the whole is as follows. It becomes sufficiently low, and the conductivity necessary for practical use can be ensured.

In addition, since the manufacturing process of Embodiment 2 does not include a process using a vapor deposition mask, it can be suitably applied to manufacturing a large display device.
Therefore, a method for manufacturing a display device that can be suitably applied to a large display device can be provided.
Further, since a process using a vapor deposition mask that induces display defects is not included, yield can be improved.
Therefore, a method for manufacturing a display device with high yield can be provided.

Furthermore, since the cathode wiring 5b is formed in addition to the reflective layer 5 in step S1, a dedicated cathode wiring process (step S4) is not required, and the manufacturing efficiency is good. Therefore, the yield can be improved.
In particular, since circuit elements such as TFTs and a plurality of wirings are formed in the lower layer of the partition wall 7 (on the element substrate 1 side), their density is high, which may be an obstacle to laser light irradiation. Assuming that the irradiation is performed from the organic EL layer 8 side, it is possible to irradiate the laser beam effectively without any obstacle.
Therefore, the organic EL layer can be sublimated more stably. Therefore, a method for manufacturing a display device with higher yield can be provided.

(Embodiment 3)
FIG. 10 is a side sectional view of the element substrate according to the third embodiment, and corresponds to FIG.
The display device according to Embodiment 3 of the present invention will be described below. In addition, about the component same as Embodiment 1, the same number is attached | subjected and the overlapping description is abbreviate | omitted.
The display device of the present embodiment includes an element substrate 1c having a configuration different from that of the element substrate 1 of the first embodiment. Specifically, the photothermal conversion layer 31b is formed as a single layer at the bottom of the V-shaped groove between the two partition walls 7a and 7b. Also, some of the manufacturing methods are different. Other than that, it is substantially the same as the description in the first embodiment. Note that the element substrate 1c refers to the entire multilayer structure formed on the element substrate 1 in this embodiment.

As shown in FIG. 10, at the bottom of the V-shaped groove between the two partition walls 7a and 7b, a single layer of the photothermal conversion layer 31b also serving as the cathode wiring is formed on the element substrate 1 side. A part of the layer is connected to the common electrode 9. Here, the photothermal conversion layer 31b is made of a material that generates heat when irradiated with infrared rays, and uses molybdenum having high conductivity. Alternatively, an alloy containing molybdenum may be used.
Further, the planar arrangement of the photothermal conversion layer 31b is formed in a stripe shape in the display region V as in the case of the cathode wiring 32 in FIG. Similarly to the description in the first embodiment, the connection between the photothermal conversion layer 31b and the cathode main line is established by the contact hole 9c. If the surface resistance of the common electrode 9 can be made uniform, the photothermal conversion layer 31b may be arranged in an island shape as in the second embodiment.

Next, with reference to FIG. 4, the element substrate manufacturing method according to the third embodiment will be described focusing on differences from the first embodiment.
First, steps S3 and S7 are changed in the flowchart of FIG. 4, and step S4 is not necessary.
Specifically, in step S3, the photothermal conversion layer 31b made of molybdenum is formed using a sputtering method and a photolithography method.
In step S7, laser light is irradiated from the organic EL layer 8 side (Z-axis (−) side) formed covering the partition walls 7a and 7b, the photothermal conversion layer 31b, and the pixel electrode 6 toward the photothermal conversion layer 31b. . Thus, also in the third embodiment, the irradiation direction of the laser light is from the opposite side of the first embodiment. Since the photothermal conversion layer 31b is a single layer, laser light may be irradiated from the element substrate 1 side as in the first embodiment.

As described above, according to the present embodiment, in addition to the effects in the first embodiment, the following effects can be obtained.
The photothermal conversion layer 31b is a material that generates heat when irradiated with infrared rays, and is made of molybdenum having a high conductivity. Therefore, even a single layer structure can function as a photothermal conversion layer and a cathode wiring.
The planar arrangement of the photothermal conversion layer 31b is formed in a stripe shape in the display region V.
Therefore, even when the surface resistance of the thinned common electrode 9 is increased, the periodic connection by the photothermal conversion layer 31b is ensured in the display region V, and thus the emission luminance in the vicinity of the center portion of the display region V is secured. The decrease can be suppressed.
Therefore, a display device with high display quality can be provided.

In addition, the manufacturing process of Embodiment 3 does not include a process using a vapor deposition mask, and thus can be suitably applied to manufacturing a large display device.
Therefore, a method for manufacturing a display device that can be suitably applied to a large display device can be provided.
Further, since a process using a vapor deposition mask that induces display defects is not included, yield can be improved.
Therefore, a method for manufacturing a display device with high yield can be provided.

Furthermore, since the photothermal conversion layer 31b also serves as the cathode wiring, the cathode wiring step (step S4) is not necessary, and the manufacturing efficiency is good. Therefore, the yield can be improved.
In particular, since the photothermal conversion layer 31b is a single layer, laser light irradiation may be performed from either the element substrate 1 side or the organic EL layer 8 side. Depending on the specifications of the display device, the photothermal conversion layer 31b may be used. The direction can be appropriately selected from the direction in which 31b is easily heated.
Therefore, it is possible to provide a method for manufacturing a display device with excellent manufacturing efficiency.

(Electronics)
FIG. 11 is a perspective view showing a large television on which the above-described display device is mounted.
The display device 100 described above can be mounted and used in, for example, a large television 200 as an electronic device.
The large-sized television 200 includes, for example, the display device 100 having a screen size of 42 inches as a display screen. The large television 200 is provided so as to be remotely operable by a remote controller (not shown), and displays images of various channels on the display device 100 by the operation of the remote controller.
Since the display device 100 is a self-luminous organic EL display device, the display device 100 is configured to be thinner than a liquid crystal display device that requires a light source such as a backlight. Moreover, the display device 100 with high display quality is mounted.
Therefore, the large-sized television 200 that is thin and has high display quality can be provided.

  In addition, the present invention is not limited to a large-sized television, and any electronic device provided with a display unit may be used. For example, the present invention may be applied to a monitor or a notebook computer. Further, it can be used for various electronic devices such as mobile phones, display devices for car navigation systems, PDAs (Personal Digital Assistants), mobile computers, digital cameras, digital video cameras, in-vehicle devices, and audio devices.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the above-described embodiment. A modification will be described below.

(Modification 1)
This will be described with reference to FIGS. 3B and 7B.
In each of the above embodiments, the pixel electrode is described as a transparent electrode. However, the pixel electrode is not limited to this configuration, and may function as a reflective electrode. For example, the electrode may be configured as a reflective electrode by using a material capable of ensuring a predetermined light reflectance and flatness for the pixel electrode 6 itself. As a material of the pixel electrode 6, for example, amorphous metal can be used.
According to this structure, since the formation process (step S1) of the reflective layer 5 can be omitted, manufacturing efficiency can be further improved.
Therefore, a method for manufacturing a display device with high yield can be provided.

(Modification 2)
This will be described with reference to FIG.
In each said embodiment, although the organic EL layer 8 was demonstrated as a laminated body which consists of a some organic thin film layer, it is not limited to this structure. For example, a so-called tandem organic EL light emitting device may be used in which an intermediate charge generation layer is interposed between organic light emitting layers.
According to this configuration, a large display device with low power consumption can be provided.

  1, 1b, 1c ... as an element substrate (as a laminated body), 4 ... a flattening layer, 5 ... a reflective layer, 5b ... a cathode wiring, 6 ... a pixel electrode, 7, 7a, 7b ... a partition, 8 ... an organic thin film layer 9 ... Common electrode as common cathode, 9c ... Contact hole, 10 ... Cathode protective layer, 14 ... CF layer as color filter, 17 ... Counter substrate, 18 ... Display panel, 20 ... Flexible substrate, 25 DESCRIPTION OF SYMBOLS Insulating layer 31, 31b ... Photothermal conversion layer, 32 ... Cathode wiring, 100 ... Display apparatus as electro-optical device, 200 ... Large television as electronic equipment, V ... Display area.

Claims (10)

A method of manufacturing an electro-optical device having a plurality of pixels,
Forming a pixel electrode to be an opening of the pixel on a substrate;
Forming a photothermal conversion layer in a gap portion between the pixel electrode and the adjacent pixel electrode;
Forming a cathode wiring on the photothermal conversion layer; and
A step of exposing a part of the cathode wiring to form a partition wall for partitioning the plurality of pixel electrodes;
Forming an organic thin film layer by covering the pixel electrode and the partition using a vapor deposition method;
Irradiating laser light toward the photothermal conversion layer from the substrate side;
Using a vapor deposition method to cover the organic thin film layer and forming a light-transmitting common cathode,
The method of manufacturing an electro-optical device, wherein the cathode wiring and the common cathode are electrically connected through the exposed portion of the cathode wiring. The pixel electrode comprises a transparent electrode,
The method of manufacturing an electro-optical device according to claim 1, further comprising a step of forming a reflective layer overlapping the pixel electrode before the step of forming the pixel electrode. The cathode wiring is connected to a cathode trunk formed on the substrate,
The laminated wiring portion including the photothermal conversion layer and the cathode wiring is formed in a stripe shape, a lattice shape, or an island shape for each of the plurality of pixels in a plan view. A method for manufacturing the electro-optical device according to 1 or 2. The photothermal conversion layer is made of molybdenum, titanium, chromium, or an alloy containing at least one of these,
The electricity according to any one of claims 1 to 3, wherein the cathode wiring is made of aluminum, gold, copper, or an alloy containing at least one of them. Manufacturing method of optical device.   The laser beam includes an infrared ray having a wavelength of 800 nm, and an irradiation intensity capable of giving the photothermal conversion layer the amount of heat necessary to sublimate the organic thin film layer in contact with the exposed portion of the cathode wiring, and The method of manufacturing an electro-optical device according to claim 1, wherein the irradiation is performed for an irradiation time. In the partition forming step, the partition made of a substantially black resin is formed using a photolithography method,
6. The method of manufacturing an electro-optical device according to claim 1, wherein the exposed portion of the cathode wiring is positioned at a bottom of a groove formed in the partition. In the step of forming the organic thin film layer, the organic thin film layer including a plurality of layers including a light emitting layer that emits substantially white light is formed,
After the step of forming the common cathode, the method further includes a step of forming a cathode protective layer and a step of attaching a counter substrate facing the substrate,
The counter substrate is formed with color filters of each color including red, blue, and green corresponding to each pixel, and the light emitted from the pixel is a color light that is transmitted and selected by the corresponding color filter. The method of manufacturing an electro-optical device according to claim 1, wherein the light is emitted from the counter substrate. A method of manufacturing an electro-optical device having a plurality of pixels,
A step of forming a cathode wiring with the same material as the reflective layer and the reflective layer on the substrate;
Forming a light transmissive pixel electrode to be an opening of the pixel on an upper layer side of the reflective layer;
Forming a photothermal conversion layer on the cathode wiring;
A step of exposing a part of the cathode wiring to form a partition wall for partitioning the plurality of pixel electrodes;
Forming an organic thin film layer by covering the pixel electrode and the partition using a vapor deposition method;
Irradiating laser light toward the photothermal conversion layer from the organic thin film layer side;
Using a vapor deposition method to cover the organic thin film layer and form a light-transmitting common cathode,
The method of manufacturing an electro-optical device, wherein the cathode wiring and the common cathode are electrically connected through the exposed portion of the cathode wiring. A method of manufacturing an electro-optical device having a plurality of pixels,
Forming a pixel electrode to be an opening of the pixel on a substrate;
Forming a cathode wiring in a gap portion between the pixel electrode and the adjacent pixel electrode;
A step of exposing a part of the cathode wiring to form a partition wall for partitioning the plurality of pixel electrodes;
Forming an organic thin film layer by covering the pixel electrode and the partition using a vapor deposition method;
Irradiating laser light from the substrate side or the organic thin film layer side toward the cathode wiring;
Using a vapor deposition method to cover the organic thin film layer and forming a light-transmitting common cathode,
The cathode wiring composed of a photothermal conversion material that generates heat upon irradiation with the laser light and the common cathode are electrically connected via the exposed portion of the cathode wiring. Manufacturing method of optical device.   The method of manufacturing an electro-optical device according to claim 9, wherein the cathode wiring is made of molybdenum or an alloy containing molybdenum.

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