JP2013134847A - Display panel manufacturing method and display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display panel manufacturing method which, when forming another layer on top of an organic function layer, does not cause the surface of the organic function layer to be roughened by a mask, and a display panel obtained by this manufacturing method.SOLUTION: A method for manufacturing a display panel which is composed of a plurality of layers including at least one organic function layer laminated on a base substrate includes: a first step of forming a first layer 15(R) which is an organic function layer on the base substrate, one layer for each subpixel; and a second step of placing a mask M2 on the top side of the substrate in such a way that at least one subpixel equivalent part of the first layer 15(R) is located in a plan view at an opening M2a of the plate-like mask M2 having the opening M2a and then forming a second layer on top of the first layer 15(R). In the second step, there exists a clearance d1 in a plan view between an outer peripheral part 15a of the at least one subpixel equivalent part of the first layer 15(R) located in the opening M2a and an edge part M2b of the opening M2a of the mask.

Description

  The present invention relates to a display panel such as an organic EL (Electro Luminescence) panel and a manufacturing method thereof.

In recent years, organic EL display panels in which organic EL elements are arranged on a substrate as a display device are becoming widespread. The organic EL display panel has characteristics such as high visibility because it uses an organic EL element that performs self-emission, and excellent impact resistance because it is a complete solid element.
An organic EL element is a current-driven light-emitting element, and includes a plurality of organic functional layers such as an organic light-emitting layer that performs an electroluminescence phenomenon by recombination of carriers (electrons and holes) between an anode and a cathode electrode pair. These functional layers are laminated. In addition to the organic light emitting layer, the organic functional layer includes an electron injection layer for injecting electrons into the organic light emitting layer, a hole injection layer for injecting holes, and electrons injected from the electron injection layer. There are an electron transport layer that transports to the light emitting layer and a hole transport layer that transports holes injected from the hole injection layer to the organic light emitting layer. In the organic EL display panel, the organic EL element corresponding to each color of red (R), green (G), and blue (B) is a subpixel, and a combination of three subpixels of R, G, and B is 1. It corresponds to a pixel (one pixel).

Such a functional layer may be formed by a vacuum vapor deposition method using a vapor deposition mask.
In Patent Document 1, after a hole transport layer is formed for each pixel by a vacuum deposition method using a common mask having an opening having a size corresponding to the pixel (pixel), the size corresponding to a sub-pixel smaller than the pixel is disclosed. Disclosed is a method in which an organic light-emitting layer of each color is sequentially formed for each sub-pixel by a vacuum deposition method using an individual mask having an opening, and then an electron transport layer is formed again using a common mask thereon. Has been.

As such a mask, a mask obtained by patterning a metal plate such as SUS by etching or laser, or a mask in which a metal is deposited by plating after forming a resist pattern is used.
At this time, if there is a gap between the mask and the lower layer (deposition base) on which the functional layer is formed, the material to be deposited wraps around the gap, and the organic functional layer reaches the unnecessary area. Will be formed. Therefore, in order to increase masking accuracy, the mask may be placed in close contact with the film formation base using a magnet or the like.

JP 2011-40277 A

The mask is formed by patterning by etching, laser, or the like, or by metal deposition by plating using a resist pattern. At that time, a sharp part or a burr may be generated at the edge of the opening. Yes (hereinafter simply referred to as “Bali”).
According to the method of Patent Document 1, an individual mask is placed on a hole transport layer that is an organic functional layer to form a light emitting layer of each color. At this time, the individual mask is placed in close contact with the hole transport layer formed using the common mask. Since the opening of the individual mask is smaller than the opening of the common mask, the edge portion of the opening of the individual mask is placed on the hole transport layer. The organic functional layer is relatively soft because it is not hardened by chemical bonds such as crosslinking. Therefore, when the part where such burrs are generated is placed on and in close contact with the hole transport layer, irregularities are formed on the surface of the hole transport layer under the mask when the mask is removed. The Rukoto.

  When a thin solid film is formed on the organic light-emitting layer having the unevenness, when the unevenness is large or sharp, the portion where the solid film is not formed on the portion (hereinafter referred to as “step breakage”). ") May occur. In the case where the solid film formed on the organic light emitting layer is a cathode, electricity does not flow to the portion where the step breakage occurs, which causes image quality failure. In particular, when a metal cathode is used in a top emission structure, the cathode must be formed as thin as possible in order to extract light from the cathode side.

Even when another layer is formed on the organic functional layer using a common mask, if the mask is misaligned, the edge portion of the mask opening is placed on the organic functional layer. Consequently, the organic functional layer is uneven.
The present invention has been made in view of the above-described problems, and when forming another layer on the organic functional layer while realizing high masking accuracy, the surface of the organic functional layer is caused to have irregularities due to the mask. An object of the present invention is to provide a display panel manufacturing method that does not occur and a display panel obtained by the manufacturing method.

  A display panel manufacturing method according to one embodiment of the present invention is a display panel manufacturing method in which a plurality of layers including at least one organic functional layer are stacked on a base substrate, and is a first organic functional layer. And a portion corresponding to at least one subpixel of the first layer in a plan view is located in the opening of the plate-shaped mask having the opening in the first step of forming the layer of the substrate on the base substrate for each subpixel. A second step of disposing the mask on the substrate and forming a second layer on the first layer, wherein the second step is positioned in the opening. A gap exists in a plan view between an outer peripheral edge of the portion corresponding to the at least one subpixel of the first layer and an edge of the opening of the mask.

  In the method for manufacturing a display panel according to one aspect of the present invention, in the second step, the outer edge of the first layer and the edge of the opening of the mask are located in the opening when viewed in plan. There is a gap between the first and second burrs that exist at the edge of the opening of the mask when the mask is placed on the base layer or the first layer. Since there is no contact with the layer, the surface of the first layer is not damaged and unevenness does not occur. Further, even if the alignment is slightly deviated, since there is a gap, the burrs present at the edge of the opening of the mask do not contact the first layer located in the opening, and the first The surface of the layer is not damaged and unevenness does not occur.

It is a schematic block diagram which shows the structure of the display apparatus which concerns on embodiment of this invention. It is a partially expanded plan view of a display panel. 3 is a schematic cross-sectional view illustrating a configuration of a display panel according to Embodiment 1. FIG. 6 is a schematic cross-sectional view showing a part of the manufacturing process of the display panel according to Embodiment 1. FIG. 6 is a schematic cross-sectional view showing a part of the manufacturing process of the display panel according to Embodiment 1. FIG. 6 is a schematic cross-sectional view showing a part of the manufacturing process of the display panel according to Embodiment 1. FIG. FIG. 6 is a partially enlarged plan view in one step of the manufacturing process of the display panel according to the first embodiment. 6 is a schematic cross-sectional view illustrating a configuration of a display panel according to Embodiment 2. FIG. 12 is a schematic cross-sectional view showing a part of the manufacturing process of the display panel according to Embodiment 2. FIG. FIG. 10 is a partially enlarged plan view in one step of the manufacturing process of the display panel according to the second embodiment.

<< Outline of One Embodiment of the Present Invention >>
A method for manufacturing a display panel according to one aspect of the present invention is a method for manufacturing a display panel in which a plurality of layers including at least one organic functional layer are stacked on a base substrate, the first being an organic functional layer. And a portion corresponding to at least one subpixel of the first layer in a plan view is located in the opening of the plate-shaped mask having the opening in the first step of forming the layer of the substrate on the base substrate for each subpixel. A second step of disposing the mask on the substrate and forming a second layer on the first layer, wherein the second step is positioned in the opening. A gap exists in a plan view between an outer peripheral edge of the portion corresponding to the at least one subpixel of the first layer and an edge of the opening of the mask.

  In the method for manufacturing a display panel according to one aspect of the present invention, in the second step, when viewed in plan, the outer peripheral edge of the first layer located in the opening and the edge of the opening of the mask The first layer in which burrs existing at the edge of the opening of the mask are located in the opening when the mask is placed on the base layer or the first layer. Therefore, the surface of the first layer is not damaged and unevenness is not generated. Further, even if the alignment is slightly deviated, since there is a gap, the burrs present at the edge of the opening of the mask do not contact the first layer located in the opening, and the first The surface of the layer is not damaged and unevenness does not occur. As a result, the occurrence of step breaks can be prevented.

  Further, when another functional layer is formed on the first layer on which the unevenness is formed, the film thickness of the functional layer formed on the uneven portion is locally nonuniform. When a portion having a non-uniform thickness locally exists in the functional layer, there is a problem that charges are concentrated on the portion and deterioration is promoted. Further, when a portion having a non-uniform thickness is locally formed in the organic light emitting layer, a problem of uneven light emission occurs. However, in the method for manufacturing a display panel according to one embodiment of the present invention, as described above, the surface of the first layer is not damaged and unevenness is not generated. it can.

  Further, in the second step, when the region where the first layer is formed is located only in the opening in plan view, the mask is placed on the base layer of the first layer. Therefore, when viewed from the side, the uppermost portion of the first layer located in the opening is located above the lower surface of the mask by the thickness of the first layer. In this case, since there is no gap between the mask and the base layer, the material for forming the second layer enters the gap when the second layer is formed, and an extra second layer is formed there. It will not be done. Thereby, the masking accuracy can be increased.

  When the region where the first layer is formed is present in a region other than the opening when viewed in plan, the mask is placed on the first layer of the first layer that is not in the opening. It is placed. In this case, a gap is generated between the mask and the base layer, but the size of the gap is the same as the film thickness of the first layer and is very narrow. Therefore, when the second layer is formed, The material for forming the second layer is less likely to enter the gap, and the formation of an extra second layer can be suppressed. Thereby, the masking accuracy can be increased.

In the specific aspect of the method for manufacturing a display panel according to one aspect of the present invention, in the second step, the mask is provided with an opening corresponding to a part of each of the plurality of subpixels. It is characterized by that.
In the specific aspect of the method for manufacturing a display panel according to one embodiment of the present invention, in the second step, the second layer is an organic light emitting layer, and some of the plurality of subpixels are R , G, and B are sub-pixels corresponding to any one color.

In a specific aspect of the method for manufacturing a display panel according to one embodiment of the present invention, in the second step, the mask has the openings at positions corresponding to all the sub-pixels.
Moreover, in a specific aspect of the method for manufacturing a display panel according to one aspect of the present invention, in the second step, the second layer is an electrode layer, and is a solid film that uniformly covers all the subpixels. It is characterized by being.

The display panel according to one embodiment of the present invention includes a hole transport layer and a light emitting layer formed on the hole transport layer, and the hole transport layer and the light emitting layer are spaced from each other for each subpixel. The portion corresponding to one subpixel of the light emitting layer is larger in size in plan view than the portion corresponding to one subpixel of the hole transport layer.
Here, the plane means the main surface of the display panel, and the plan view means a case where the display panel is viewed from a direction perpendicular to the main surface. Further, the side surface means a surface other than the main surface perpendicular to the main surface of the display panel, and the side view means a case where the display panel is viewed from a direction perpendicular to the side surface. Further, the planar view and the side view do not necessarily mean a state when viewed with the naked eye, but are used to represent a relative positional relationship between each component of the display panel including the substrate. That is, it means a state in which the component located on the back side is visible through the component located on the near side in the plan view and the side view.

<< Embodiment 1 >>
[1. Overall configuration of display device]
Below, the structure of the display apparatus 1 provided with the display panel which concerns on embodiment is demonstrated using FIG.
As shown in FIG. 1, the display device 1 includes a display panel 10 and a drive control unit 20 connected thereto. The display panel 10 is a panel that uses an electroluminescence phenomenon of an organic material, and includes a plurality of organic EL elements arranged in a matrix, for example. The drive control unit 20 includes four drive circuits 21 to 24 and a control circuit 25.

In the actual display device 1, the arrangement of the drive control unit 20 with respect to the display panel 10 is not limited to this.
[2. Display panel configuration]
The configuration of the display panel 10 will be described with reference to FIGS.
FIG. 2 is a partially enlarged plan view showing a schematic configuration of the display panel 10. FIG. 3 is a partial cross-sectional view showing a schematic configuration of the display panel 10, and is a cross-sectional view taken along line AA ′ in FIG. The display panel 10 is a so-called top emission type in which the upper side of FIG. In the following description, the display surface side (side on which the functional layer of the substrate 11 is formed) is up and the opposite side is down.

As shown in FIG. 2, the display panel 10 includes an organic EL element having an organic light emitting layer 16 (see FIG. 3) corresponding to one of red (R), green (G), and blue (B) emission colors. A subpixel 100 is provided, and the subpixels 100 are arranged in a matrix.
As shown in FIG. 3, the display panel 10 is formed using a substrate 11 as a base. On the substrate 11, anodes 12 are formed at intervals. On the substrate 11 and the anode 12, a bank 13 in which a plurality of openings 13a (see FIG. 4A) are formed at positions corresponding to the sub-pixels 100 is provided.

A hole injection layer 14, a hole transport layer 15, an organic light emitting layer 16, an electron transport layer 17, and an electron injection layer 18 are sequentially stacked inside the opening 13a. The hole injection layer 14, the hole transport layer 15, the organic light emitting layer 16, the electron transport layer 17, and the electron injection layer 18 are collectively referred to as an organic functional layer.
Although the hole injection layer 14 is formed inside the opening 13a, the hole injection layer 14 protrudes from the opening 13a and is also formed on the peripheral edge thereof. A hole transport layer 15 is formed on the hole injection layer 14. In the present embodiment, the size of the hole injection layer 14 and the hole transport layer 15 in the plan view is the same.

On the hole transport layer 15, an organic light emitting layer 16 corresponding to any one of R, G, and B is formed. The organic light emitting layer 16 is formed so as to cover the upper surface and side surfaces of the hole transport layer 15. That is, the organic light emitting layer 16 is larger in size when viewed in plan than the hole transport layer 15.
And the electron carrying layer 17 is formed so that the upper surface and side surface of the organic light emitting layer 16 may be covered. That is, the electron transport layer 17 is larger in size in plan view than the organic light emitting layer 16. An electron injection layer 18 is formed on the electron transport layer 17. In the present embodiment, the sizes of the electron transport layer 17 and the electron injection layer 18 in the plan view are the same.

A cathode 19 is formed on the electron injection layer 18 as a solid film covering the entire surface of the display panel 10.
In FIG. 2, in order to illustrate the subpixel 100 in an easy-to-understand manner, the cathode 19 is removed. As shown in FIG. 2, the openings 13a provided in the bank 13 are arranged in a matrix (in the XY direction) in units of pixels. The opening 13a is a region where the organic light emitting layer 16 is formed, and the shape thereof is a long shape having a long side in the Y direction. For example, the side along the X direction is about 50 to 110 [μm], The sides along the Y direction are formed with dimensions of about 150 to 250 [μm].

  As shown in FIG. 2, the opening 13a has openings 13aR, 13aG, and 13aB corresponding to R, G, and B colors. The organic light emitting layer 16 corresponding to R is formed in the opening 13aR, G is formed in the opening 13aG, and B is formed in the opening 13aB. The areas corresponding to the openings 13aR, 13aG, and 13aB are the subpixels 100, and one pixel (pixel) 200 is configured by combining the three subpixels of the subpixels 100R, 100G, and 100B. The sub-pixels 100 are arranged for each column in R, G, and B color units, and the sub-pixels 100 belonging to the same column are the openings 13a corresponding to the same color.

The opening 13a is covered with a plurality of layers such as the electron injection layer 18, and these layers are formed so as to protrude to the outside of the opening 13a. Therefore, in FIG. The region is smaller than the subpixel 100 and surrounded by a broken line. In FIG. 2, only some of the openings 13a are denoted by reference numerals.
<Substrate, anode>
The substrate 11 is a rear substrate in the display panel 10, and a TFT layer (not shown) including TFTs (thin film transistors) for driving the display panel 10 by an active matrix method is formed on the surface thereof. The TFT layer includes an anode 12 which is a wiring portion for supplying power from the outside to each TFT. However, in this embodiment, only the anode is taken out for easy understanding. Show.

The anode 12 is formed for each organic light emitting layer 16 formed in the opening 13a. Since the display panel 10 is a top emission type, a light reflective material is selected as the material of the anode 12.
<Bank>
The bank 13 defines a subpixel region divided into each color, and also serves as a pedestal that supports the metal mask when the organic light emitting layer 16 is formed by vacuum deposition.

<Hole injection layer>
The hole injection layer 14 is provided for the purpose of promoting the injection of holes from the anode 12 to the organic light emitting layer 16.
<Hole transport layer>
Returning to the partial cross-sectional view of FIG. 3, the hole transport layer 15 has a function of transporting holes injected from the anode 12 to the organic light emitting layer 16.

<Organic light emitting layer>
The organic light emitting layer 16 is a portion that emits light by recombination of carriers (holes and electrons), and is configured to include an organic material corresponding to any of R, G, and B colors. An organic light emitting layer 16 including an organic material corresponding to R is formed in the opening 13aR, an organic material corresponding to G is formed in the opening 13aG, and an organic material corresponding to B is formed in the opening 13aB.

<Electron transport layer>
The electron transport layer 17 has a function of transporting electrons injected from the cathode 19 to the organic light emitting layer 16.
<Electron injection layer>
The electron injection layer 18 has a function of promoting injection of electrons from the cathode 19 to the organic light emitting layer 16.

<Cathode>
Since the display panel 10 is a top emission type, the cathode 19 is formed using a light-transmitting material as a material.
<Others>
Although not shown in FIG. 3, a sealing layer is provided on the cathode 19 for the purpose of preventing the organic light emitting layer 16 from being deteriorated by contact with moisture, air, or the like. Since the display panel 10 is a top emission type, a light transmissive material such as SiN (silicon nitride) or SiON (silicon oxynitride) is selected as the material of the sealing layer.

Moreover, the organic light emitting layer 16 formed in each opening part 13a can also be made into the organic light emitting layer of the same color altogether.
<Material of each layer>
Next, the material of each layer demonstrated above is illustrated. Needless to say, each layer can be formed using materials other than those described below.

Substrate 11: alkali-free glass, soda glass, non-fluorescent glass, phosphate glass, borate glass, quartz, acrylic resin, styrene resin, polycarbonate resin, epoxy resin, polyethylene, polyester, silicone resin, alumina, etc. Insulating material Anode 12: Ag (silver), Al (aluminum), alloy of silver, palladium and copper, alloy of silver, rubidium and gold, aluminum alloy, Mo (molybdenum), MoCr (alloy of molybdenum and chromium) ), MoW (alloy of molybdenum and tungsten), NiCr (alloy of nickel and chromium)
A known transparent conductive film may be provided on the surface of the anode 12. As a material of the transparent conductive film, for example, indium tin oxide (ITO) or indium zinc oxide (IZO) can be used.

Bank 13: Acrylic resin, polyimide resin, novolak type phenol resin Hole injection layer 14: Triazole derivative, oxadiazole derivative, imidazole derivative, polyarylalkane derivative, pyrazoline derivative and pyrazolone derivative, phenylenediamine derivative, arylamine derivative , Amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, porphyrin compounds, aromatic tertiary amine compounds, styrylamine compounds, butadiene compounds, polystyrene derivatives, hydrazone derivatives, triphenylmethane derivatives , Tetraphenylbenzine derivatives (all described in JP-A-5-163488), MoOx (molybdenum oxide), WOx (tan oxide) Metal oxide), metal nitride or metal oxynitride such as MoxWyOz (molybdenum-tungsten oxide), hole transport layer 15: triazole derivative, oxadiazole derivative, imidazole derivative, polyarylalkane derivative, pyrazoline derivative and Pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, polyphyrin compounds, aromatic tertiary amine compounds, styrylamine compounds, butadiene compounds, Polystyrene derivatives, hydrazone derivatives, triphenylmethane derivatives, tetraphenylbenzine derivatives (all described in JP-A-5-163488)
Organic light emitting layer 16: Oxinoid compound, perylene compound, coumarin compound, azacoumarin compound, oxazole compound, oxadiazole compound, perinone compound, pyrrolopyrrole compound, naphthalene compound, anthracene compound, fluorene compound, fluoranthene compound, tetracene compound, pyrene compound, Coronene compound, quinolone compound and azaquinolone compound, pyrazoline derivative and pyrazolone derivative, rhodamine compound, chrysene compound, phenanthrene compound, cyclopentadiene compound, stilbene compound, diphenylquinone compound, styryl compound, butadiene compound, dicyanomethylenepyran compound, dicyanomethylenethiopyran Compound, fluorescein compound, pyrylium compound, thiapyrylium compound, serenapyri Umum compounds, telluropyrylium compounds, aromatic ardadiene compounds, oligophenylene compounds, thioxanthene compounds, cyanine compounds, acridine compounds, metal complexes of 8-hydroxyquinoline compounds, metal complexes of 2-bipyridine compounds, Schiff salts and Group III metals Fluorescent substances such as complexes, oxine metal complexes, and rare earth complexes (all described in JP-A-5-163488)
Electron transport layer 17: nitro-substituted fluorenone derivative, thiopyrandioxide derivative, difequinone derivative, perylenetetracarboxyl derivative, anthraquinodimethane derivative, fluorenylidenemethane derivative, anthrone derivative, oxadiazole derivative, perinone derivative, quinoline complex derivative (All described in JP-A-5-163488), phosphorus oxide derivatives, triazole derivatives, todiazine derivatives, silole derivatives, dimesityl boron derivatives, triaryl boron derivatives Electron injection layer 18: lithium, barium, calcium, potassium, cesium, sodium Low work function metals such as rubidium, low work function metal salts such as lithium fluoride, and low work function metal oxides such as barium oxide. Cathode 19: Use of a conductive material. Can, for example, aluminum, silver, neodymium - aluminum alloy, gold - aluminum alloy, a magnesium - metals and such silver alloy, ITO (indium tin oxide), IZO (indium zinc oxide) and the like. Further, it may be formed of a multilayer film.

The configuration of the display panel 10 has been described above. Next, a method for manufacturing the display panel 10 will be illustrated.
[3. Manufacturing method of display panel]
Here, the manufacturing method of the display panel 10 according to the embodiment will be described with reference to FIGS. 4 to 6 are cross-sectional views schematically showing the manufacturing process of the display panel 10.

Here, in FIGS. 4-6, since the manufacturing process by a vacuum evaporation method is shown, the upper and lower sides are reverse to FIG. However, for convenience of explanation, in FIGS. 4 to 6, the side on which the functional layer of the substrate 11 is formed will be described as the upper side and the opposite side as the lower side.
First, the substrate 11 is placed in a chamber of a sputter deposition apparatus. Then, a predetermined sputtering gas is introduced into the chamber, and the anode 12 is formed based on the reactive sputtering method. The anode 12 can also be formed by vacuum deposition or the like.

  Subsequently, for example, a photosensitive resist material is prepared as a bank material. This bank material is uniformly applied on the substrate 11 and the anode 12 and prebaked, and then a mask having a pattern capable of forming the opening 13a is overlaid. Then, after exposure from above the mask, uncured excess bank material is washed out with a developer. Finally, the bank 13 is completed by washing with pure water (FIG. 4A).

  Next, as shown in FIG.4 (b), the positive hole injection layer 14 is formed by the vacuum evaporation method using the mask M1. At this time, the mask M1 is placed on the bank 13, and the edge M1b of the opening M1a of the mask M1 is also located on the bank 13. However, since the bank 13 is cross-linked and has relatively hard physical properties, the bank 13 is less likely to be damaged by the burr on the edge M1b, and the top surface of the bank 13 is less likely to be uneven. Further, even if irregularities occur on the upper surface of the bank 13, the irregularities are not usually large enough to cause a problem.

At this time, since the width W2 of the opening M1a of the mask M1 (in this case, the width in the X-axis direction) W2 is wider than the width W1 of the opening 13a of the bank 13, the hole injection layer 14 13a is formed so as to protrude from the upper surface of the bank.
Subsequently, as shown in FIG. 4C, the hole transport layer 15 is formed by vacuum deposition using the mask M1. At this time, the mask M1 is not removed or replaced, and is continuously used as it is after the hole injection layer 14 is formed. Again, since the width W2 of the opening M1a of the mask M1 is larger than the width W1 of the opening 13a of the bank 13, the hole transport layer 15 is formed to protrude from the inside of the opening 13a of the bank 13 to the upper surface of the bank. The hole injection layer 14 is similarly formed.

Subsequently, the mask M1 is removed and replaced with a mask M2. Then, as shown in FIG. 7, the mask M2 is arranged so that the opening M2a of the mask M2 is located on the hole transport layer 15 (R), and as shown in FIG. The organic light emitting layer 16 is formed on the hole transport layer 15 by using a vacuum deposition method.
FIG. 7 is a plan view showing a state before the mask M2 is arranged so that the opening M2a is positioned on the hole transport layer 15 (R) and the organic light emitting layer 16 (R) is formed.

The opening M2a of the mask M2 is provided only at a position where the organic light emitting layer 16 corresponding to any one color of R, G, and B is to be formed. 5A and 7, the opening M2a is provided only at a position where the R-color organic light emitting layer 16 (R) is to be formed. Therefore, in FIG. 5A, the organic light emitting layer 16 (R) is formed.
At this time, the width (here, the width in the X-axis direction) W3 of the opening M2a of the mask M2 is wider than the width W2 of the opening M1a of the mask M1. Therefore, when viewed in plan (when viewed from the positive side to the negative side along the Z axis), a gap is formed between the edge M2b of the opening M2a of the mask M2 and the outer peripheral edge 15a of the hole transport layer 15. d1 exists. Thus, the organic light emitting layer 16 (R) is formed so as to protrude from the uppermost surface 15 b of the hole transport layer 15, cover the side surfaces of the hole transport layer 15 and the hole injection layer 14, and reach the bank 13. .

  Here, the hole transport layer 15 is formed by a vacuum deposition method and is not subjected to a process such as crosslinking, and thus is relatively soft unlike the bank 13 and the like. However, since the opening M2a is not provided in the portion of the mask M2 that is in contact with the uppermost surfaces 15b (G) and 15b (B) of the hole transport layers 15 (G) and 15 (B), the most due to the burr of the opening M2a. Unevenness is not formed on the upper surfaces 15b (G) and 15b (B). As shown in FIG. 7, when viewed in a plan view, there is a gap d1 between the edge M2b of the opening M2a of the mask M2 and the outer peripheral edge 15a of the hole transport layer 15 (R). Edge M2b does not contact the hole transport layer 15 (R). Therefore, no irregularities are formed in the hole transport layer 15 (R) by the burr at the edge M2b.

  In the above description, the hole transport layer 15 formed at the position where the organic light emitting layer 16 for each color of R, G, B is to be formed is referred to as R, G for convenience. , B suffixes are used to form hole transport layers 15 (R), 15 (g), and 15 (b), respectively. However, the hole transport layers 15 (R), 15 (g), and 15 (b) may all be the same in terms of composition.

  Next, as illustrated in FIG. 5B, the organic light emitting layer 16 (G) is formed on the hole transport layer 15 by vacuum deposition using the mask M2. Here, even though the mask M2 is the same as the mask M2 used to form the organic light emitting layer 16 (R) in FIG. 5A, the opening M2a of the mask M2 is provided only at a position corresponding to G. It may be a mask. After the organic light emitting layer 16 (R) is formed, the mask M2 is once removed, and the mask M2 is moved and arranged so that the opening M2a is located at the position where the G-color organic light emitting layer 16 (G) is formed. After that, the organic light emitting layer 16 (G) is formed. Therefore, the organic light emitting layer 16 (G) is formed so as to protrude from the upper surface of the hole transport layer 15 and cover the side surfaces of the hole transport layer 15 and the hole injection layer 14 and reach the bank 13. .

At this time, the mask M2 is placed on the organic light emitting layer 16 (R) so that the lower surface M2c is in close contact with the uppermost surface 16b (R) of the organic light emitting layer 16 (R).
Here, the organic light emitting layer 16 is formed by a vacuum deposition method and is not subjected to a process such as crosslinking, and thus is relatively soft unlike the bank 13 and the like. However, since the opening M2a is not provided in the portion of the mask M2 that is in contact with the top surface 16b (R) of the organic light emitting layer 16 (R), the top surface 16b (R) is uneven by the burr of the opening M2a. There is nothing. In this case, since the mask M2 is placed on the uppermost surface 16b (R) of the organic light emitting layer 16 (R), the lower surface of the mask M2 is connected to the hole transport layers 15 (G) and 15 (B). Are not touching. Although the opening M2a is located above the hole transport layer 15 (G), the lower surface of the mask M2 is not in contact with the hole transport layer 15 (G). Unevenness is not formed on the layer 15 (G).

  Subsequently, the mask M2 used to form the organic light emitting layers 16 (R) and 16 (G) is once removed, and an opening M2a is located at a position where the B-color organic light emitting layer 16 (B) is to be formed. After moving and arranging the mask M2, the organic light emitting layer 16 (B) is formed by vacuum deposition as shown in FIG. 5 (c). Also here, the organic light emitting layer 16 (G) is formed so as to protrude from the upper surface of the hole transport layer 15, cover the side surfaces of the hole transport layer 15 and the hole injection layer 14, and reach the bank 13.

At this time, the mask M2 includes the organic light emitting layers 16 (R), 16 such that the lower surface M2c is in close contact with the uppermost surfaces 16b (R), 16a (G) of the organic light emitting layers 16 (R), 16 (G). (G) It is mounted on.
Here, since the opening M2a is not provided in the portion in contact with the uppermost surfaces 16b (R) and 16a (G) of the mask M2, the uppermost surfaces 16b (R) and 16a (G) are uneven due to the burr of the opening M2a. Never formed. Further, since the mask M2 is placed on the uppermost surfaces 16b (R) and 16a (G) of the organic light emitting layer 16 (R), the lower surface of the mask M2 is in contact with the hole transport layer 15 (B). Not. Although the opening M2a is located above the hole transport layer 15 (B), the lower surface of the mask M2 is not in contact with the hole transport layer 15 (B). Unevenness is not formed on the layer 15 (B).

Next, the mask M2 is removed, and as shown in FIG. 6A, the electron transport layer 17 is formed on the organic light emitting layer 16 by vacuum evaporation using the mask M3. The mask M3 is provided with openings M3a at positions corresponding to all the organic light emitting layers 16.
Here, the width (here, the width in the X-axis direction) W4 of the opening M3a of the mask M3 is wider than the width W3 of the opening M2a of the mask M2. Therefore, there is a gap between the edge M3b of the opening M3a of the mask M3 and the outer peripheral edge 16a of the organic light emitting layer 16 when viewed in plan (when viewed from the positive side to the negative side along the Z axis). d2 exists. Thereby, the electron transport layer 17 is formed so as to protrude from the upper surface of the organic light emitting layer 16, cover the side surface of the organic light emitting layer 16, and reach the bank 13.

  Here, the organic light emitting layer 16 is relatively soft, and the opening M3a is provided at a position corresponding to each organic light emitting layer 16 of the mask M3. However, when viewed in a plan view, the organic light emitting layer 16 and the edge M3b of the opening M3a of the mask M3 Since the gap d2 exists between the outer peripheral edge 16a of the light emitting layer 16, the edge M3b does not contact the organic light emitting layer 16. Therefore, no irregularities are formed on the organic light emitting layer 16 by the burr at the edge M3b.

At this time, since the organic light emitting layer 16 is completely contained in each opening M2a of the mask M2 in plan view, the mask M3 is placed in close contact with the bank 13.
Subsequently, as shown in FIG. 6B, the electron injection layer 18 is formed on the electron transport layer 17 by vacuum evaporation using the mask M3. At this time, the mask M3 is not removed or replaced, and is used continuously as it is from the time when the electron transport layer 17 is formed.

Then, as shown in FIG. 6C, the cathode 19 is formed as a solid film by vacuum deposition.
Although not shown, a sealing layer is formed on the upper surface of the cathode 19 by forming a light transmissive material such as SiN or SiON by sputtering or CVD.
The display panel 10 is completed through the above steps.

<< Embodiment 2 >>
[1. Overall configuration of display device]
In the display panel 10 according to Embodiment 1, the electron transport layer 17 and the electron injection layer 18 are also formed separately for each subpixel, but the present invention is not limited to this. The electron transport layer 17 and the electron injection layer 18 may be formed as a solid film covering the organic light emitting layer 16 for R, G, and B colors in pixel units, or as one solid film covering all the organic light emitting layers 16. It may be formed.

In the second embodiment, the case where the electron transport layer 17 and the electron injection layer 18 are formed as a solid film covering the organic light emitting layer 16 for R, G, and B colors in units of pixels will be described.
In addition, in order to avoid duplication of description, about the same component as Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
[1. Display panel configuration]
FIG. 8 is a sectional view showing a schematic configuration of the display panel 110 according to the second embodiment. As shown in the figure, in the display panel 110, the electron transport layer 117 and the electron injection layer 118 are formed as a solid film in units of pixels instead of being formed for each subpixel.

The electron transport layer 117 and the electron injection layer 118 are basically the same as the electron transport layer 17 and the electron injection layer 18 of the first embodiment, except that they are formed as a pixel unit solid film. Made of the same material and have the same characteristics.
[2. Manufacturing method of display panel]
The manufacturing method of anode 12 to organic light emitting layer 16 is the same as the method shown in FIGS.

After the organic light emitting layer 16 is formed, the mask M2 is removed and replaced with the mask M4. The mask M4 is disposed at a position where the opening M4a of the mask M4 corresponds to the pixel 200. And as shown to Fig.9 (a), the electron carrying layer 117 is formed by a vacuum evaporation method.
Here, the width (width in the X-axis direction) W6 of the opening M4a of the mask M4 is set wider than the width (width in the X-axis direction) W5 of the pixel 200, and the edge M4b of the opening M4a and the organic light emitting layer. There is a gap d3 between the outer peripheral edge 16a and the portion closest to the edge M4b. Therefore, the edge M4b of the opening M4a of the mask M4 is not in contact with any of the organic light emitting layers 16 (R), 16 (G), and 16 (B). Accordingly, the organic light emitting layers 16 (R), 16 (G), and 16 (B) are not formed with unevenness due to the burr at the edge M4b.

Here, the width W5 of the pixel 200 is defined between the outer peripheral edge 16a (R) of the organic light emitting layer 16 (R) and the outer peripheral edge 16a (B) of the organic light emitting layer 16 (B) in the X-axis direction. Out of distance
The farthest distance is W5.
Next, as shown in FIG. 9B, an electron injection layer 118 is formed on the electron transport layer 117 by vacuum deposition. At this time, the mask M4 is not removed or replaced, and is continuously used as it is since the electron transport layer 117 is formed.

Then, as shown in FIG. 9C, the cathode 19 is formed as a solid film by vacuum deposition.
Although not shown, a sealing layer is formed on the upper surface of the cathode 19 by forming a light transmissive material such as SiN or SiON by sputtering or CVD.
The display panel 110 is completed through the above steps.

<< Summary of Embodiment >>
As described above, according to the method for manufacturing a display panel according to the present embodiment, after the first layer, which is an organic functional layer, is formed on the base substrate for each subpixel, the mask having the opening is used as the first layer. When the second layer is formed on the first layer by arranging the first layer so that at least one sub-pixel equivalent portion of the layer is located in the opening in the plan view, There is a gap between the outer peripheral edge of the portion (corresponding to at least one subpixel) located in the opening of the mask of the first layer and the edge of the mask opening. Thereby, the edge of the mask does not come into contact with the first layer. Therefore, even when burrs exist on the edge of the mask, the first layer is not damaged by the burrs, and unevenness does not occur. Therefore, a locally non-uniform thickness portion does not occur in the second layer. Accordingly, it is possible to prevent the location where charges are concentrated on the second layer and the occurrence of disconnection, and a display panel with good image quality can be provided.

Here, in Embodiment 1, the first layer is the hole transport layer 15 or the organic light emitting layer 16. When the first layer is the hole transport layer 15, the second layer is the organic light emitting layer 16. When the first layer is the organic light emitting layer 16, the second layer is the electron transport layer 17.
In the second embodiment, the first layer is the organic light emitting layer 16, and the second layer is the electron transport layer 117.

[Modification]
Although the first and second embodiments have been described above, the present invention is not limited to these embodiments. For example, the following modifications can be considered.
(1) Although not shown in FIG. 3, a color filter corresponding to each color of R, G, B is disposed above the cathode 19 in accordance with the position of each organic light emitting layer 16. . The color filter is a transparent layer provided to transmit visible light having a wavelength corresponding to R, G, and B.

Specifically, the color filter applies, for example, an ink containing a color filter material and a solvent to a substrate for forming a color filter provided with a bank in which a plurality of openings are formed in a matrix for each pixel. It is formed by a process.
As a color filter material, for example, a color resist manufactured by JSR Corporation can be used.

(2) The shape of the opening 13a being “long” means that the opening has a long side and a short side, and is not necessarily rectangular. For example, the shape may be a square, a circle, an ellipse, or the like.
(3) FIG. 3 shows a configuration in which the layers of the anode 12 to the cathode 19 are laminated on the substrate 11. In the present invention, one layer lacking any one of the layers is formed so that one layer functions as a plurality of layers, or further includes another layer such as a transparent conductive layer. It can also be configured.

  The method of manufacturing the display panel of the present invention is suitable for, for example, a method of manufacturing a display panel used as a display for home or public facilities, or various display devices for business use, a television device, or a portable electronic device. Is available.

DESCRIPTION OF SYMBOLS 10 Display panel 11 Substrate 12 Anode 13 Bank 13a Opening 14 Hole injection layer 15 Hole transport layer 15a, 16a Outer peripheral edge 15b, 16b Top surface 16 Organic light emitting layer 17 Electron transport layer 18 Electron injection layer 19 Cathode 100 Subpixel 200 Pixel M1, M2, M3, M4 Mask M1a, M2a, M3a, M4a Opening M1b, M2b, M3b, M4b Edge M1c, M2c, M3c, M4c Lower surface

Claims (6)

A method for manufacturing a display panel in which a plurality of layers including at least one organic functional layer are laminated on a base substrate,
Forming a first layer, which is an organic functional layer, on a base substrate for each subpixel;
The mask is disposed on the upper side of the substrate so that at least one subpixel equivalent portion of the first layer is located in the opening of the plate-shaped mask having an opening in a plan view, Forming a second layer on the layer, and
In the second step, there is a gap in plan view between an outer peripheral edge of the portion corresponding to the at least one subpixel of the first layer located in the opening and an edge of the opening of the mask. A manufacturing method of a display panel, characterized in that it exists. The method for manufacturing a display panel according to claim 1, wherein, in the second step, the mask is provided with an opening corresponding to a part of each of the plurality of subpixels. In the second step, the second layer is an organic light emitting layer, and some of the plurality of subpixels are subpixels corresponding to any one color of R, G, and B. The manufacturing method of the display panel according to claim 2, wherein The method for manufacturing a display panel according to claim 1, wherein, in the second step, the mask has the openings at positions corresponding to all the sub-pixels. 5. The display panel manufacturing method according to claim 4, wherein, in the second step, the second layer is an electrode layer, and is a solid film that uniformly covers all the sub-pixels. A hole transport layer, and a light emitting layer formed on the hole transport layer,
The hole transport layer and the light emitting layer are formed at intervals from each other for each subpixel,
The display panel according to claim 1, wherein a portion corresponding to one subpixel of the light emitting layer is larger in size in plan view than a portion corresponding to one subpixel of the hole transport layer.

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