JP2008135325A - Organic EL display device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily provide firm contact between an auxiliary wire compensating for the high resistance of a common electrode and the common electrode in an organic EL display device without a mask deposition process. <P>SOLUTION: Pixel electrodes 2 and a bank 3 are formed on the main surface of the support board 1. The auxiliary wire 6 is disposed on the bank 3, and is composed of three layers consisting of a lower layer 8, a middle layer 9, and an upper layer 10, which overhangs the middle layer 9 to form an eaves concealing the middle layer 9 from above. An organic film 4 vapor deposited on the upper layer 10 of the pixel electrodes 2 is not deposited on the middle layer 9 due to a shadowing effect by the eaves of the upper layer 10. When the transparent common electrode 5 is formed thereon by sputtering, the common electrode 5 wraps around the inside of the organic film 4 and is deposed on the under layer 8 of the auxiliary wire 6 for firm contact. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an organic EL display device using an organic light emitting element, and more particularly to an organic EL display device that achieves both improvement in definition and brightness in a method of extracting display light above a support substrate of an organic light emitting element. Regarding manufacturing.

  A structure using electroluminescence (EL) or an injection type light emitting diode is known as a display device using a current control type light emitting element (hereinafter also referred to as a display). Among them, a current control type EL (charge injection type EL, hereinafter also referred to as organic light emitting element or organic EL) display device using an organic material as a light emitting layer realizes high brightness, large area, low manufacturing cost and full color display. It is attracting attention as a possible display device.

  In an organic EL display device using an organic light emitting element, an insulating support substrate (here, a glass substrate) such as glass is used, and a thin film transistor (TFT) generally used as a switching element for selecting a pixel is formed. Since it is a substrate, hereinafter, the support substrate is also referred to as a TFT substrate. The inner surface of the TFT substrate is provided with a plurality of first electrodes (usually pixel electrodes) arranged in a matrix, an organic light emitting layer made of a plurality of thin films of organic material is laminated on the pixel electrodes, and a common electrode that covers all the pixels And an organic light emitting layer is sandwiched between a pixel electrode and a common electrode. Here, a method of extracting display light above the TFT substrate (organic light emitting element formation surface: main surface side) is referred to as a top emission type. Note that the method of extracting display light below the TFT substrate is referred to as a bottom emission type.

  FIG. 11 is a cross-sectional view schematically illustrating an example of the overall structure of a top emission type organic EL display device. Note that in FIG. 11, illustration of a thin film transistor, a control element that controls light emission luminance, and the like is omitted for the sake of simplicity.

  As shown in FIG. 11, the organic EL display device includes a support substrate 1 on which a pixel portion 14 that is a pixel circuit including a plurality of organic light emitting elements is formed on a main surface, and a light-transmitting property that protects the pixel portion 14 from an external atmosphere. The sealing plate (also referred to as a sealing can) 15 is made to face, the sealing material 17 is applied to the peripheral portions of both substrates and cured, and the inside thereof is isolated and sealed from the outside atmosphere by bonding, This prevents moisture from entering the pixel portion 14. As the sealing plate 15, a translucent glass substrate or the like is used. In general, a transparent hygroscopic agent 16 is mainly applied to or pasted on the inner surface of the sealing plate 16 in order to suppress deterioration of the light emission characteristics of the organic light emitting element of the pixel portion 14 due to humidity.

The organic EL display device configured as described above has an organic EL light emitting layer (both simply an organic light emitting layer and an organic layer) between a first electrode (pixel electrode) and a second electrode (common electrode) constituting the pixel unit 14. The organic EL light emitting layer emits light with the magnitude of the flowing current by applying a predetermined voltage between the first electrode and the second electrode. The emitted light L is emitted from the translucent sealing plate 15 side. Patent Document 1 can be cited as a disclosure of this type of top emission type organic EL display device. Patent Document 2 and Patent Document 2 can be cited as auxiliary wiring for compensating for the resistance of the common electrode related to the problem of the present invention described later.
JP 2002-318556 A Japanese Patent Laid-Open No. 10-12386

  Compared with the bottom emission type, the top emission type organic EL display device configured as described above has an advantage that a light emitting layer can be installed on a pixel circuit including a thin film transistor, so that the aperture ratio can be increased. . However, on the other hand, the common electrode needs to be a transparent conductive film, and a non-metallic conductive thin film such as ITO or IZO is used. Since the electric resistance of these conductive thin films such as ITO and IZO is higher than that of the metal thin film, it is desirable to provide an auxiliary wiring to compensate for this low resistance.

  The auxiliary wiring is formed on the organic layer of the organic EL element or on the common electrode by mask vapor deposition, when it is formed side by side on the pixel electrode of the TFT substrate which is the pixel electrode forming substrate, or the TFT substrate In some cases, the contact hole is formed under the passivation film and a contact hole is opened in the passivation film.

  When the auxiliary wiring is formed by mask vapor deposition, the thin line is limited to a line width of about 20 μm. This can be used for large displays such as for TVs, but this size is too wide for small high-definition displays such as mobile devices. Considering the mask alignment accuracy, a wider width can be used for auxiliary wiring. Must be assigned.

  Even when the auxiliary wiring is formed side by side on the main surface of the TFT substrate on the pixel electrode, the alignment accuracy is about the same as that of the photolithography process (hereinafter referred to as the “photo process”), and the line width of several μm is possible, which affects the aperture ratio. Can be formed within a range that does not give. However, in order to make electrical contact with the common electrode, it is necessary not to attach the organic layer on the auxiliary wiring. In addition, when configuring a color organic EL display device, it is necessary to perform mask vapor deposition even for each color common layer, and mask vapor deposition is necessary even in the case of monochrome display. is required.

  Regarding the formation of the auxiliary wiring, the above Patent Documents 1 and 2 disclose a configuration in which the auxiliary wiring is formed in the same layer as the pixel electrode, and is electrically insulated from the pixel electrode and electrically connected to the common electrode. Has been. However, in the techniques described in these documents, it is necessary to vapor-deposit an organic layer that is a light emitting layer while avoiding auxiliary wiring, and all the organic layers including a common layer of a plurality of colors are vapor-deposited by mask. Increases productivity significantly.

  An object of the present invention is to solve the above-described problems in the prior art, and an object of the present invention is to easily and reliably make contact with a common electrode on the auxiliary wiring provided on the substrate side with accuracy of a photo process without using mask deposition. An object of the present invention is to provide an organic EL display device and a manufacturing method thereof.

A typical configuration of the present invention for achieving the above object will be described as follows. That is,
(1) An organic EL display device according to the present invention includes a support substrate on which a pixel portion made of an organic light emitting element is formed, and a translucent sealing plate that protects the pixel portion from an external atmosphere, and the pixel portion Is adjacent to a reflective first electrode provided for each pixel, an organic light-emitting layer disposed on the first electrode, and a second electrode made of a transparent conductive film provided in common to a plurality of pixels. An auxiliary wiring provided on the insulating layer between the first electrodes and connected to the second electrode;
The auxiliary wiring includes a lower layer film made of a metal film, and a wide layer formed on the upper layer of the lower layer film and having a ridge protruding from an edge of the lower layer film toward the first electrode. The ends of the two electrodes are electrically connected from above the lower layer film at a portion hidden in the ridge by the wide layer.

  Further, the auxiliary wiring of the organic EL display device of the present invention consists of three layers: an intermediate layer film stacked on the lower layer film made of the metal film, and an upper layer film stacked on the intermediate layer film, The upper layer film is a metal film made of the same material as the lower layer film, and the intermediate layer film is a metal film made of a material different from that of the lower layer film and the upper layer film.

(2) In the method for manufacturing an organic EL display device according to the present invention, a thin film transistor, a reflective first electrode provided for each pixel, and an edge of an adjacent first electrode are provided on the main surface of the support substrate. Forming an insulating layer,
A three-layer metal material serving as an auxiliary wiring is formed along the insulating layer and sputtered thereon, and patterned to form a three-layer film composed of a lower layer film, a middle layer film, and an upper layer film having a rectangular cross section. ,
Selectively etching only the middle layer film of the three layer film exposed on the side surface of the three layer film, and retracting the edge of the middle layer film from the edge of the lower layer film and the upper layer film;
By depositing an organic light emitting layer from above the main surface of the support substrate, and subsequently sputtering a common electrode common to a plurality of pixels,
The common electrode is connected to the lower layer film of the auxiliary wiring due to the difference in the vacuum deposition and sputtering.

  In the invention, the three-layer metal material is characterized in that the lower layer film and the upper layer film are titanium, the intermediate layer film is aluminum, and the selective etching of the intermediate layer film is wet etching in which only aluminum is dissolved. To do.

  It should be noted that the present invention is not limited to the above-described configurations and the configurations described in the embodiments described later, and it goes without saying that various modifications can be made without departing from the technical idea of the present invention. .

  Even if the organic layer constituting the light emitting layer is deposited on the entire surface without a mask on the auxiliary wiring with a fine line width formed on the substrate by the photo process, the auxiliary wiring and the common electrode are contacted, so the process is simplified. It becomes. Since the organic layer does not have good coverage by vacuum deposition, if there is a structure that shadows the auxiliary wiring, an uncovered portion remains. When the common electrode, which is a transparent electrode, is formed by sputtering, the throwing power is much higher than that of vacuum deposition, so the common electrode also adheres to the parts not covered by vacuum deposition, and the contact between the auxiliary wiring and the common electrode Is taken.

  In addition, by forming high-precision auxiliary wiring on the TFT substrate, fine pattern mask vapor deposition is possible without sacrificing buying efficiency and excluding the portion where mask vapor deposition is required by coating different organic layers with different emission colors. Since the common electrode is not necessary, the common electrode can be vapor-deposited in a batch, and the productivity is also ensured. Furthermore, since high-precision auxiliary wiring can be used, a high aperture ratio of the top emission organic EL display device or a simplification of the TFT process can be achieved even in a medium-sized or large-sized display.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings of the examples.

  FIG. 1 is a plan view of an essential part for explaining Example 1 of an organic EL display device according to the present invention. FIG. 2 is a cross-sectional view taken along the line A-A ′ of FIG. 1. The plan view of FIG. 1 shows sub-pixel R (red), G (green), and B (blue) portions that constitute one color pixel. In FIG. 1, each of the sub-pixels R (red), G (green), and B (blue) is indicated by a pixel electrode 2. On the pixel electrode 2, as shown in FIG. 4. The common electrode 5 is laminated. A bank 3 made of an insulating layer is formed between the sub-pixels R (red), G (green), and B (blue), and an auxiliary wiring 6 is formed on the bank 3. Here, for the sake of simplicity, the sub-pixel is also simply referred to as a pixel unless it is necessary to distinguish the sub-pixel from the pixel.

  As shown in FIG. 2, the pixel electrode 2 constituting each subpixel is formed on the main surface of the support substrate 1 so as to be insulated by the bank 3. The bank 3 is an insulating layer and has a function of partitioning the organic film 4 constituting the organic light emitting layer of the adjacent subpixel. In FIG. 1, the bank 3 is formed so as to surround the pixel. The auxiliary wiring 6 surrounds the pixel electrode 2, and the arrangement direction of the same color pixels (up and down direction in FIG. 1) and the arrangement direction of the sub-pixels R (red), G (green), and B (blue) constituting one color pixel element. It is formed surrounding (from the left-right direction in FIG. 3). However, it can also be formed in stripes only in the vertical direction or only in the horizontal direction. The bank 3 is formed so as to cover a part of the edge of the pixel electrode 2, and the auxiliary wiring 6 is formed on the bank 3. The auxiliary wiring 6 includes three layers of a lower layer 8, a middle layer 9, and an upper layer 10. All three layers are metal films with low resistance.

  The three-layer auxiliary wiring 6 is formed such that the middle layer 9 recedes from the edges of the lower layer 8 and the upper layer 10. As shown in FIG. 2, the auxiliary wiring 6 has a shape in which the center is recessed. In other words, the upper layer 10 protrudes more than the middle layer 9 so that the upper layer 10 becomes a wrinkle of the middle layer 9. When the organic film 4 is deposited, the shadowing effect of the upper layer 10 causes a shadowing effect on the middle layer 9. Is not attached. The transparent common electrode 5 is formed by sputtering. As a result, the common electrode 5 wraps inside the organic film 4 and is attached to the lower layer 8, and contact (electrical connection) between the common electrode 5 and the auxiliary wiring 6 is established. The three layers constituting the auxiliary wiring 6 are preferably made of low resistance metal as described above, but only the lower layer may be made of low resistance metal, and the middle layer and upper layer may be made of an insulator and a semiconductor. However, considering the purpose of reducing the electrical resistance of the auxiliary wiring, it is desirable that all three layers be metal films.

  The three-layer auxiliary wiring 6 is formed as follows, for example. First, a titanium (Ti) / aluminum (Al) / titanium (Ti) three-layer metal is stacked to form a sputter film. This is patterned by a photo process and etched to obtain a three-layer (Ti / Al / Ti) film having a rectangular cross section. Thereafter, only the Al layer of the middle layer 9 is selectively etched using a weak alkali or aluminum etching solution, whereby the auxiliary wiring 6 in which the Al layer of the middle layer 0 is recessed is obtained. Due to this cross-sectional shape, the common electrode 5 and the auxiliary wiring 6 are contacted as described above.

  With the configuration of Embodiment 1, auxiliary wiring can be formed by a simplified process, and a high-definition, high aperture ratio organic EL display device having a low-resistance common electrode can be obtained.

  FIG. 3 is a plan view of an essential part for explaining Example 2 of the organic EL display device according to the present invention. 4 is a cross-sectional view taken along line B-B ′ of FIG. Similar to the first embodiment, the plan view of FIG. 3 shows sub-pixels R (red), G (green), and B (blue) constituting one color pixel. The same reference numerals as those in the drawing of Embodiment 1 denote the same functional parts. In the second embodiment, the auxiliary wiring 6 is buried in the bank 3 of the support substrate (TFT substrate) 1, and contact is made with the common electrode 5 on the surface through the through hole 7. The auxiliary wiring 6 is arranged in the bank 3 in the arrangement direction of the sub-pixels R (red), G (green), and B (blue) that constitute one color pixel (the horizontal direction in FIG. 3). The auxiliary wiring 6 and the common electrode 5 on the surface are in contact through the through hole 7.

  A pixel electrode 2 is formed on the main surface of the TFT substrate 1, and a conductive layer 2 'made of the same material as the pixel electrode is left in the same layer as the pixel electrode. The through hole 7 reaches the conductive layer 2 '. Three layers of auxiliary wiring 6 are formed in the through hole 7. In the same manner as in Example 1, the upper layer metal 10 protrudes from the middle layer metal 9 in the layer auxiliary wiring 6, and when the organic film 4 is deposited, the upper layer metal 10 shadows the middle layer metal 9 to form the organic film. 4 is not attached. The transparent common electrode 5 is formed by sputtering. As a result, the common electrode 5 wraps inside the organic film 4 and attaches to the lower layer metal 8, and the common electrode 5 and the auxiliary wiring 6 are brought into contact.

  The three layers constituting the auxiliary wiring 6 are preferably made of a low-resistance metal as in the first embodiment, but at least only the lower layer is made of a low-resistance metal, and the middle and upper layers are made of an insulator and a semiconductor. There may be. However, considering the purpose of reducing the electrical resistance of the auxiliary wiring, it is desirable that all three layers be metal films. The conductive layer 2 ′ below the three-layer auxiliary wiring 6 has an effect of further reducing the resistance of the auxiliary wiring 6.

  Also with the configuration of Example 2, the auxiliary wiring can be formed by a simplified process, and a high-definition, high aperture ratio organic EL display device having a low-resistance common electrode can be obtained.

  FIG. 5 is a plan view of an essential part for explaining Example 3 of the organic EL display device according to the present invention. FIG. 6 is a cross-sectional view taken along line C-C ′ in FIG. 5. In the third embodiment, the same low-resistance metal film 11 as the data wiring 23 and the power supply line 24 formed on the main surface of the support substrate 1 is provided, and the edge is higher than the edge of the upper bank 3. A receding metal film 12 is laminated. The data wiring 23 and the power supply line 24 are formed in the pixel region, and are shown by dotted lines in FIG. An organic film is vacuum-deposited on the pixel electrode 2, and a transparent common electrode 5 is sputtered thereon. At this time, due to the difference in coverage between vacuum deposition and sputtering, the common electrode 5 goes around the receding portion of the metal film 12 and is connected to the low-resistance metal film 11 to be contacted. The recessing process of the metal film 12 utilizes the difference in etching property as in the above embodiment.

  Also with the configuration of Embodiment 3, the auxiliary wiring can be formed by a simplified process, and a high-definition, high aperture ratio organic EL display device having a low-resistance common electrode can be obtained.

  FIG. 7 is a plan view of an essential part for explaining Example 4 of the organic EL display device according to the present invention. FIG. 8 is an enlarged plan view of the auxiliary wiring in FIG. FIG. 9 is a cross-sectional view taken along the line D-D ′ of FIG. 8. In the fourth embodiment, the auxiliary wiring 6 is provided in the same color pixel along the two arrangement directions (vertical direction). The auxiliary wiring 6 is composed of three wiring layers (for example, Ti / Al / Ti) formed on the main surface of the substrate 1 in the same layer as the pixel electrode 2. In this case, the three lower layers 8 and 10 are Ti, and the middle layer is Al.

  After forming three wiring layers on the main surface of the substrate 1, the pixel electrode forming portion and the auxiliary wiring forming portion are separated by dry etching. A silicon nitride (SiN) film is formed thereon by CVD to form a protective film (passivation film). This protective film becomes the bank 3 around the pixel electrode. That is, this protective film is removed at the pixel electrode formation portion of the three wiring layers. At this time, a plurality of contact holes 7 are formed along the edge of the auxiliary wiring forming portion. In the contact hole 7, the side surfaces of the three wiring layers are exposed. By immersing in the etching solution in this state, the Al film which is the middle layer 9 is etched, retreats from the edges of the lower layer 8 and the upper layer 10, and the side layer 9 is recessed. This state is shown in FIG. Thereafter, the upper layer of the pixel electrode forming portion is removed by reactive ion etching to expose the middle layer 9. The middle layer 9 is an Al film and is highly reflective.

  In this manner, the shadowing structure having the cross-sectional structure shown in FIG. 9 is formed on both sides (pixel electrode 2 side) of the contact hole 7. An organic film 4 constituting the organic light emitting layer is deposited from above, and a transparent conductive film such as ITO, which becomes the common electrode 5, is continuously sputtered thereon. As a result, ITO or the like wraps around and adheres to the lower layer 8 of the auxiliary wiring 6 to which the organic film 4 is not attached due to the difference in the throwing power, and the common electrode 5 and the auxiliary wiring 6 come into contact with each other.

  Also with the configuration of Example 4, auxiliary wiring can be formed by a simplified process, and a high-definition, high aperture ratio organic EL display device having a low-resistance common electrode can be obtained.

  FIG. 10 is an equivalent circuit including a drive circuit of the organic EL display device. The organic EL display device includes a support substrate 1 on which TFTs and organic EL elements are formed, and a sealing plate 15. In this example, the pixel PX includes TFT1, TFT2, a storage capacitor Cs, and an organic EL element. A plurality of pixels PX are arranged in a matrix to form a pixel portion (display area) 14. The data line 23 is driven by the data line driving circuit 21. The scanning line 22 is driven by the scanning line driving circuit 20. A power supply line 24 that is a current supply line to the organic EL element is connected to a current supply circuit (not shown) via a current supply bus line 25.

It is a principal part top view explaining Example 1 of the organic electroluminescent display apparatus by this invention. It is sectional drawing along the A-A 'line of FIG. It is a principal part top view explaining Example 2 of the organic electroluminescence display by this invention. FIG. 4 is a cross-sectional view taken along line B-B ′ of FIG. 3. It is a principal part top view explaining Example 3 of the organic electroluminescence display by this invention. FIG. 6 is a cross-sectional view taken along line C-C ′ of FIG. 5. It is a principal part top view explaining Example 4 of the organic electroluminescence display by this invention. It is an enlarged plan view of the auxiliary wiring in FIG. It is sectional drawing along the D-D 'line of FIG. It is an equivalent circuit including a drive circuit of an organic EL display device. It is sectional drawing which illustrates typically the example of the whole structure of a top emission type organic electroluminescence display.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Support substrate, 2 ... Pixel electrode, 3 ... Bank, 4 ... Organic film | membrane which comprises an organic light emitting layer, 5 ... Common electrode, 6 ... Auxiliary wiring, 7 ... Contact hole, 8 ... lower layer, 9 ... middle layer, 10 ... upper layer, 14 ... pixel part, 15 ... sealing plate.

Claims (10)

A support substrate on which a pixel portion made of an organic light emitting element is formed, and a translucent sealing plate that protects the pixel portion from an external atmosphere;
The pixel unit includes a reflective first electrode provided for each pixel, an organic light emitting layer disposed on the first electrode, and a second electrode made of a transparent conductive film provided in common to a plurality of pixels. An auxiliary wiring provided on the insulating layer between the adjacent first electrodes and connected to the second electrode,
The auxiliary wiring has a lower layer film made of a metal film, and a wide layer that forms a ridge that is an upper layer of the lower layer film and that protrudes from an edge of the lower layer film toward the first electrode,
The organic EL display device, wherein an end portion of the second electrode is electrically connected from above the lower layer film at a portion hidden by the wide layer. In claim 1,
The auxiliary wiring consists of three layers: an intermediate layer film laminated on the lower layer film made of the metal film, and an upper layer film laminated on the intermediate layer film,
The organic EL display device, wherein the upper layer film is a metal film made of the same material as the lower layer film, and the intermediate layer film is a metal film made of a material different from the lower layer film and the upper layer film. In claim 2,
The organic EL display device, wherein the lower layer film and the upper layer film are titanium films, and the middle layer film is an aluminum film. A support substrate on which a pixel portion made of an organic light emitting element is formed, and a translucent sealing plate that protects the pixel portion from an external atmosphere;
The pixel unit includes a reflective first electrode provided for each pixel, an organic light emitting layer disposed on the first electrode, and a second electrode made of a transparent conductive film provided in common to a plurality of pixels. An auxiliary wiring provided on the insulating layer between the adjacent first electrodes and connected to the second electrode,
The auxiliary wiring has a lower layer film made of a metal film, and a wide layer formed on the upper layer of the lower layer film and a ridge protruding from the edge of the lower layer film toward the first electrode,
A low-resistance metal layer provided along the insulating layer below the insulating layer and between the adjacent first electrodes;
Having a contact hole in the insulating layer;
The end portion of the second electrode is electrically connected from above the lower layer film at a portion hidden by the wide layer in the contact hole, and the lower layer film is connected to the low resistance metal layer. An organic EL display device comprising: In claim 4,
The auxiliary wiring consists of three layers: an intermediate layer film laminated on the lower layer film made of the metal film, and an upper layer film laminated on the intermediate layer film,
The organic EL display device, wherein the upper layer film is a metal film made of the same material as the lower layer film, and the intermediate layer film is a metal film made of a material different from the lower layer film and the upper layer film. In claim 4,
The organic EL display device, wherein the lower layer film and the upper layer film are titanium films, and the middle layer film is an aluminum film. In claim 4,
The organic EL display device, wherein the low-resistance metal layer is made of the same material as the first electrode. In claim 4,
The auxiliary wiring consists of two layers, an intermediate film laminated on the lower film made of the metal film,
The organic EL display device, wherein the intermediate layer film is a metal film made of a material different from that of the lower layer film. A method for manufacturing an organic EL display device, comprising: a support substrate on which a pixel portion made of an organic light emitting element is formed; and a translucent sealing plate that protects the pixel portion from an external atmosphere,
On the main surface of the support substrate, a thin film transistor, a reflective first electrode provided for each pixel, an insulating layer provided to cover an edge of the adjacent first electrode,
A three-layer metal material serving as an auxiliary wiring is formed along the insulating layer and sputtered thereon, and patterned to form a three-layer film composed of a lower layer film, a middle layer film, and an upper layer film having a rectangular cross section. ,
Selectively etching only the middle layer film of the three layer film exposed on the side surface of the three layer film, and retracting the edge of the middle layer film from the edge of the lower layer film and the upper layer film;
By depositing an organic light emitting layer from above the main surface of the support substrate, and subsequently sputtering a common electrode common to a plurality of pixels,
A method for manufacturing an organic EL display device, characterized in that the common electrode is connected to a lower layer film of the auxiliary wiring due to a difference in coverage between the vacuum deposition and sputtering. In claim 9,
In the three-layer metal material, the lower layer film and the upper layer film are titanium, and the middle layer film is aluminum,
The method of manufacturing an organic EL display device, wherein the selective etching of the intermediate layer film is wet etching that dissolves only aluminum.

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