Method of manufacturing a display device

Abstract

The light emitting element layer forming process includes: a process of forming a plurality of first electrodes (21a) on the thin film transistor layer; a process of forming an edge cover so as to cover the peripheral end portions of the first electrodes (21a); a process of forming a light emitting functional layer on each of the first electrodes (21a) exposed from the edge cover; and a process of forming a second electrode so as to cover each of the light emitting functional layers and the edge cover. In the process of forming the first electrodes, a plurality of dummy electrodes (21d) made of the same material as the first electrodes (21a) are formed around the first electrodes (21a) when the first electrodes (21a) are formed. In the process of forming the edge cover, the plurality of dummy electrodes (21d) are removed before the edge cover is formed.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a display device. Background Technology

[0002] In recent years, self-emissive organic EL (OLED) display devices using organic electroluminescence (EL) elements have attracted attention as alternatives to liquid crystal displays. Here, the top-emitting OLED display device includes an organic EL element layer, on which multiple first electrodes (reflective electrodes), multiple organic EL layers, and a common second electrode (transparent electrode) are sequentially stacked, corresponding to multiple sub-pixels constituting the display area for image display.

[0003] For example, Patent Document 1 discloses a manufacturing method in which, when forming a reflective electrode containing a molybdenum-layered structure, the electrode is etched together with an aqueous solution containing nitric acid, acetic acid and phosphoric acid (a weakly acidic etching solution), and then selectively etched with an ozone aqueous solution, thereby uniformizing the outer edge shape of the reflective electrode.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2018 / 159510 Summary of the Invention

[0007] The technical problem to be solved by the present invention

[0008] However, in organic EL display devices, a bezel area is set around the display area, and multiple first electrodes are arranged in a matrix within the display area. Sometimes, the first electrodes on the bezel area side are formed to a smaller size than designed. This results in a visually perceived display unevenness, leading to a reduction in display quality.

[0009] The present invention was made in view of this, and its purpose is to suppress deviations in the size of the first electrode disposed in the display area.

[0010] Technical solutions for solving technical problems

[0011] To achieve the above objectives, the manufacturing method of the display device of the present invention includes: a thin-film transistor layer forming step, forming a thin-film transistor layer on a substrate; a light-emitting element layer forming step, forming a light-emitting element layer on the thin-film transistor layer, wherein the light-emitting element layer corresponds to a plurality of sub-pixels constituting a display area and is sequentially stacked with a plurality of first electrodes, a plurality of light-emitting functional layers and a common second electrode, the light-emitting element layer forming step including: a first electrode forming step, forming the plurality of first electrodes on the thin-film transistor layer; an edge cover forming step, forming an edge cover to cover the peripheral ends of each of the first electrodes; a light-emitting functional layer forming step, forming each of the light-emitting functional layers on each of the first electrodes exposed from the edge cover; and a second electrode forming step, forming a second electrode to cover each of the light-emitting functional layers and the edge cover, wherein in the first electrode forming step, when forming the plurality of first electrodes, a plurality of dummy electrodes made of the same material as each of the first electrodes are formed around the plurality of first electrodes, and in the edge cover forming step, the plurality of dummy electrodes are removed before forming the edge cover.

[0012] Beneficial effects

[0013] According to the present invention, deviations in the size of the first electrode disposed in the display area can be suppressed. Attached Figure Description

[0014] Figure 1 This is a top view showing the schematic configuration of an organic EL display device according to the first embodiment of the present invention.

[0015] Figure 2 This is a top view of the display area of ​​the organic EL display device according to the first embodiment of the present invention.

[0016] Figure 3 It is along Figure 1 A cross-sectional view of an organic EL display device with line III-III in the image.

[0017] Figure 4 This is an equivalent circuit diagram of the thin-film transistor layer of the organic EL display device constituting the first embodiment of the present invention.

[0018] Figure 5 This is a cross-sectional view of the organic EL layer constituting the organic EL display device of the first embodiment of the present invention.

[0019] Figure 6 It is along Figure 1 A cross-sectional view of the bezel area of ​​an organic EL display device with VI-VI lines.

[0020] Figure 7This is a cross-sectional view schematically illustrating the resin cover forming process in the edge mask forming process of the organic EL element layer process, which constitutes the method for manufacturing the organic EL display device according to the first embodiment of the present invention.

[0021] Figure 8 It is a general indication that the following... Figure 7 A cross-sectional view of the virtual electrode removal process in the edge cover formation process.

[0022] Figure 9 It is a general indication that the following... Figure 8 A cross-sectional view of the ashing process in the edge cover forming process.

[0023] Figure 10 This is a table showing the experimental results of an embodiment of the method for manufacturing an organic EL display device according to the first embodiment of the present invention.

[0024] Figure 11 This is a table showing the experimental results of a comparative example of the manufacturing method of the organic EL display device according to the first embodiment of the present invention. Detailed Implementation

[0025] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments.

[0026] First Implementation Method

[0027] Figures 1-11 This describes a first embodiment of the manufacturing method of the display device of the present invention. Furthermore, in the following embodiments, an organic EL display device having an organic EL element layer is exemplified as a display device having a light-emitting element layer. Here, Figure 1 This is a top view showing the schematic configuration of the organic EL display device 50 according to this embodiment. Furthermore, Figure 2 This is a top view of the display area D of the organic EL display device 50. Furthermore, Figure 3 It is along Figure 1 A cross-sectional view of the organic EL display device 50 along line III-III. Furthermore, Figure 4 This is an equivalent circuit diagram of the thin-film transistor layer 20 that constitutes the organic EL display device 50. Furthermore, Figure 5 This is a cross-sectional view of the organic EL layer 23 constituting the organic EL display device 50. Furthermore, Figure 6 It is along Figure 1 A cross-sectional view of the bezel region F of the organic EL display device 50 with VI-VI lines.

[0028] like Figure 1As shown, the organic EL display device 50 includes, for example, a display area D for displaying images, which is set in a rectangular shape, and a border area F set in a rectangular frame around the display area D. In addition, in this embodiment, a rectangular display area D is exemplified, but the rectangular shape also includes, for example, a shape with rounded sides, a shape with rounded corners, or a shape with a cutout on part of the side, etc., which are generally rectangular.

[0029] like Figure 2 As shown, in display area D, multiple sub-pixels P are arranged in a matrix. Furthermore, in display area D, as... Figure 2 As shown, for example, sub-pixels P having a red emitting area Lr for red display, sub-pixels P having a green emitting area Lg for green display, and sub-pixels P having a blue emitting area Lb for blue display are arranged adjacent to each other. Furthermore, in the display area D, for example, a pixel is formed by three adjacent sub-pixels P having the red emitting area Lr, the green emitting area Lg, and the blue emitting area Lb.

[0030] In the border area F Figure 1 The right end of the portion is configured as a terminal T extending in one direction (vertical in the figure). Furthermore, in the border area F, as... Figure 1 As shown, between the display area D and the terminal portion T, a bending portion B, capable of bending 180° (U-shape), is provided extending in one direction (the longitudinal direction in the figure), with the longitudinal direction as the bending axis. Furthermore, in the bezel area F, the planarization film 19a, described later, is as follows... Figure 1 , Figure 3 and Figure 6 As shown, the grooves G, which are roughly C-shaped when viewed from above, are arranged to penetrate the planarization film 19a. Here, as... Figure 1 As shown, the groove G is roughly C-shaped with an opening on the terminal T side when viewed from above.

[0031] like Figure 3 and Figure 6 As shown, the organic EL display device 50 includes: a resin substrate layer 10 as a substrate, a thin film transistor (TFT) layer 20 disposed on the resin substrate layer 10, an organic EL element layer 30 disposed on the TFT layer 20 as a light-emitting element layer, and a sealing film 40 disposed on the organic EL element layer 30.

[0032] The resin substrate layer 10 is made of, for example, polyimide resin.

[0033] like Figure 3As shown, the TFT layer 20 includes: an undercoat film 11 disposed on the resin substrate layer 10; a plurality of first TFTs 9a, a plurality of second TFTs 9b, and a plurality of capacitors 9c disposed on the undercoat film 11; and a planarization film 19a disposed on each of the first TFTs 9a, each of the second TFTs 9b, and each of the capacitors 9c. Here, in the TFT layer 20, as... Figure 2 and Figure 4 As shown, multiple gate lines 14g are arranged in a horizontal direction, extending parallel to each other. Furthermore, in the TFT layer 20, as... Figure 2 and Figure 4 As shown, multiple source lines 18f are arranged in a parallel manner along the vertical direction of the figure. Furthermore, in the TFT layer 20, as... Figure 2 and Figure 4 As shown, multiple power lines 18g are arranged in a parallel manner along the vertical direction of the diagram. Furthermore, as... Figure 2 As shown, each power line 18g is positioned adjacent to each source line 18f. Furthermore, as... Figure 4 As shown, in the TFT layer 20, a first TFT 9a, a second TFT 9b, and a capacitor 9c are provided for each sub-pixel P.

[0034] The base coating film 11, the gate insulating film 13 (described later), the first interlayer insulating film 15, and the second interlayer insulating film 17 are, for example, composed of a single layer or a stack of inorganic insulating films such as silicon nitride, silicon oxide, or silicon oxynitride.

[0035] like Figure 4 As shown, the first TFT 9a is electrically connected to the corresponding gate line 14g and source line 18f in each sub-pixel P. Furthermore, as... Figure 3 As shown, the first TFT 9a includes a semiconductor layer 12a, a gate insulating film 13, a gate 14a, a first interlayer insulating film 15, a second interlayer insulating film 17, a source 18a, and a drain 18b, which are sequentially disposed on the base coating film 11. Here, as Figure 3 As shown, the semiconductor layer 12a is disposed on the base layer film 11 in an island-like manner using a polycrystalline silicon film such as LTPS (low temperature polysilicon), and has a channel region, a source region, and a drain region. Furthermore, as... Figure 3 As shown, the gate insulating film 13 is provided in a manner that covers the semiconductor layer 12a. Furthermore, as... Figure 3 As shown, the gate 14a is disposed on the gate insulating film 13 in a manner that overlaps with the channel region of the semiconductor layer 12a. Furthermore, as... Figure 3 As shown, the first interlayer insulating film 15 and the second interlayer insulating film 17 are sequentially disposed such that they cover the gate 14a. Furthermore, as... Figure 3As shown, the source 18a and drain 18b are disposed separately on the second interlayer insulating film 17. Furthermore, as... Figure 3 As shown, source 18a and drain 18b are electrically connected to the source and drain regions of semiconductor layer 12a, respectively, via contact holes formed in the stacked film of gate insulating film 13, first interlayer insulating film 15, and second interlayer insulating film 17. Furthermore, source 18a and drain 18b, as well as source 18c and drain 18d (described later), are formed in the same layer as source line 18f and power line 18g, using the same material.

[0036] like Figure 4 As shown, the second TFT9b is electrically connected to the corresponding first TFT9a and power line 18g in each sub-pixel P. Furthermore, as... Figure 3 As shown, the second TFT 9b includes a semiconductor layer 12b, a gate insulating film 13, a gate 14b, a first interlayer insulating film 15, a second interlayer insulating film 17, a source electrode 18c, and a drain electrode 18d, which are sequentially disposed on the base coating film 11. Here, as Figure 3 As shown, the semiconductor layer 12b is disposed on the base layer film 11 in an island-like manner, for example, by a polycrystalline silicon film such as LTPS, and has a channel region, a source region, and a drain region. Furthermore, as... Figure 3 As shown, the gate insulating film 13 is provided in a manner that covers the semiconductor layer 12b. Furthermore, as... Figure 3 As shown, the gate 14b is disposed on the gate insulating film 13 in a manner that overlaps with the channel region of the semiconductor layer 12b. Furthermore, as... Figure 3 As shown, the first interlayer insulating film 15 and the second interlayer insulating film 17 are sequentially disposed to cover the gate 14b. Furthermore, as... Figure 3 As shown, the source 18c and drain 18d are disposed separately on the second interlayer insulating film 17. Furthermore, as... Figure 3 As shown, the source 18c and drain 18d are electrically connected to the source region and drain region of the semiconductor layer 12b, respectively, via contact holes formed in the stacked film of the gate insulating film 13, the first interlayer insulating film 15 and the second interlayer insulating film 17.

[0037] In addition, in this embodiment, a top-gate type first TFT 9a and a second TFT 9b are illustrated, but the first TFT 9a and the second TFT 9b may also be bottom-gate type TFTs.

[0038] like Figure 4 As shown, capacitor 9c is electrically connected to the corresponding first TFT 9a and power line 18g in each sub-pixel P. Here, as... Figure 3As shown, capacitor 9c includes: a lower conductive layer 14c formed on the same layer using the same material as gate lines 14g, gates 14a and 14b; a first interlayer insulating film 15 disposed to cover the lower conductive layer 14c; and an upper conductive layer 16c disposed on the first interlayer insulating film 15 to overlap with the lower conductive layer 14c. Furthermore, as... Figure 3 As shown, the upper conductive layer 16c is electrically connected to the power line 18g via a contact hole formed in the second interlayer insulating film 17.

[0039] The planarization film 19a has a flat surface in the display area D, and is made of organic resin materials such as polyimide resin and acrylic resin, or polysiloxane-based SOG (spin on glass) materials.

[0040] like Figure 3 As shown, the organic EL element layer 30 includes: a plurality of organic EL elements 25 corresponding to a plurality of sub-pixels P, arranged in a matrix as a plurality of light-emitting elements; and an edge mask 22a, which is arranged in a grid pattern to cover the peripheral end of the first electrode 21a described later for all sub-pixels P.

[0041] like Figure 3 As shown, the organic EL element 25 includes: a first electrode 21a disposed on the planarization film 19a of the TFT layer 20 in each sub-pixel P, an organic EL layer 23 disposed on the first electrode 21a as a light-emitting functional layer, and a second electrode 24 disposed on the organic EL layer 23.

[0042] like Figure 3As shown, the first electrode 21a is electrically connected to the drain 18d of the second TFT 9b of each sub-pixel P via a contact hole formed on the planarization film 19a. Furthermore, the first electrode 21a has the function of injecting holes into the organic EL layer 23. Moreover, to improve the efficiency of injecting holes into the organic EL layer 23, it is more preferable to form the first electrode 21a with a material having a high work function. Examples of materials constituting the first electrode 21a include, for example, metallic materials such as silver (Ag), aluminum (Al), vanadium (V), cobalt (Co), nickel (Ni), tungsten (W), gold (Au), titanium (Ti), ruthenium (Ru), manganese (Mn), indium (In), ytterbium (Yb), lithium fluoride (LiF), platinum (Pt), palladium (Pd), molybdenum (Mo), iridium (Ir), and tin (Sn). Additionally, the material constituting the first electrode 21a can be, for example, an alloy of astatine (At) / astatine oxide (AtO2). Furthermore, the material constituting the first electrode 21a can be, for example, a conductive oxide such as tin oxide (SnO), zinc oxide (ZnO), indium tin oxide (ITO), or indium zinc oxide (IZO). Additionally, the first electrode 21a can be formed by stacking multiple layers composed of the aforementioned materials. Furthermore, compound materials with high work functions can be, for example, indium tin oxide (ITO) or indium zinc oxide (IZO).

[0043] like Figure 5 As shown, the organic EL layer 23 comprises a hole injection layer 1, a hole transport layer 2, a light emission layer 3, an electron transport layer 4, and an electron injection layer 5 sequentially disposed on the first electrode 21a.

[0044] Hole injection layer 1, also known as the anode buffer layer, functions to bring the energy levels of the first electrode 21a and the organic EL layer 23 closer together and improve the hole injection efficiency from the first electrode 21a to the organic EL layer 23. Examples of materials constituting hole injection layer 1 include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyaryl alkyl derivatives, pyrazoline derivatives, phenylenediamine derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, and stilbene derivatives.

[0045] The hole transport layer 2 has the function of improving the efficiency of hole transport from the first electrode 21a to the organic EL layer 23. Examples of materials constituting the hole transport layer 2 include porphyrin derivatives, aromatic tertiary amine compounds, styrene-based amine derivatives, polyvinylcarbazole, poly-p-phenylene vinylene, polysilane, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amine-substituted chalcone derivatives, oxazole derivatives, styrene-based anthracene derivatives, fluorenone derivatives, hydrazone derivatives, zirconia derivatives, hydrogenated amorphous silicon, amorphous hydrogenated silicon carbide, zinc sulfide, or zinc selenide.

[0046] The light-emitting layer 3 is the region in which holes and electrons are injected from the first electrode 21a and the second electrode 24 respectively when a voltage is applied, and the holes and electrons recombine. Here, the light-emitting layer 3 is formed of a material with high luminous efficiency. Furthermore, examples of materials constituting the light-emitting layer 3 include, for example, oxinoid compounds [8-hydroxyquinoline metal complexes], naphthalene derivatives, anthracene derivatives, diphenylethylene derivatives, vinyl acetone derivatives, triphenylamine derivatives, butadiene derivatives, coumarin derivatives, benzoxazole derivatives, oxadiazole derivatives, oxazole derivatives, benzimidazole derivatives, thiadiazole derivatives, benzimidazole derivatives, styrene derivatives, styrene amine derivatives, bis(Styryl)Benzene derivatives, tristyrene derivatives, perylene derivatives, pyrene derivatives, aminopyrene derivatives, pyridine derivatives, rhodamine derivatives, acridine derivatives, phenoxazone, quinacridone derivatives, rubrene, poly(p-phenylenevinylene), or polysilanes.

[0047] The electron transport layer 4 functions to efficiently move electrons to the light-emitting layer 3. Here, materials constituting the electron transport layer 4 can be, for example, organic compounds such as diazole derivatives, triazole derivatives, benzoquinone derivatives, naphthoquinone derivatives, anthraquinone derivatives, tetracyanoanthraquinone dimethane derivatives, biphenylquinone derivatives, fluorenone derivatives, thiophene derivatives, and metal oxinoid compounds.

[0048] The electron injection layer 5 functions to bring the energy levels of the second electrode 24 and the organic EL layer 23 closer together, thereby improving the efficiency of electron injection from the second electrode 24 to the organic EL layer 23. This function reduces the driving voltage of the organic EL element 25. The electron injection layer 5 is also referred to as a cathode buffer layer. Examples of materials constituting the electron injection layer 5 include inorganic alkali compounds such as lithium fluoride (LiF), magnesium fluoride (MgF2), calcium fluoride (CaF2), strontium fluoride (SrF2), and barium fluoride (BaF2), as well as alumina (Al2O3) and strontium oxide (SrO).

[0049] like Figure 3 As shown, the second electrode 24 is configured to cover each organic EL layer 23 and the edge shield 22a. Furthermore, the second electrode 24 has the function of injecting electrons into the organic EL layer 23. In addition, to improve the efficiency of electron injection into the organic EL layer 23, the second electrode 24 is more preferably made of a material with a low work function. Examples of materials constituting the second electrode 24 include silver (Ag), aluminum (Al), vanadium (V), cobalt (Co), nickel (Ni), tungsten (W), gold (Au), calcium (Ca), titanium (Ti), yttrium (Y), sodium (Na), ruthenium (Ru), manganese (Mn), indium (In), magnesium (Mg), lithium (Li), ytterbium (Yb), and lithium fluoride (LiF). Furthermore, the second electrode 24 may also be formed from alloys such as magnesium (Mg) / copper (Cu), magnesium (Mg) / silver (Ag), sodium (Na) / potassium (K), astatine (At) / astatine oxide (AtO2), lithium (Li) / aluminum (Al), lithium (Li) / calcium (Ca) / aluminum (Al), and lithium fluoride (LiF) / calcium (Ca) / aluminum (Al). Additionally, the second electrode 24 may also be formed from conductive oxides such as tin oxide (SnO), zinc oxide (ZnO), indium tin oxide (ITO), and indium zinc oxide (IZO). Furthermore, the second electrode 24 may also be formed by stacking multiple layers of the above-mentioned materials. In addition, materials with low work functions include, for example, magnesium (Mg), lithium (Li), lithium fluoride (LiF), magnesium (Mg) / copper (Cu), magnesium (Mg) / silver (Ag), sodium (Na) / potassium (K), lithium (Li) / aluminum (Al), lithium (Li) / calcium (Ca) / aluminum (Al), lithium fluoride (LiF) / calcium (Ca) / aluminum (Al), etc.

[0050] The edge cover 22a is made of, for example, an organic resin material such as polyimide resin or acrylic resin, or a polysiloxane-based SOG material. Here, as... Figure 3 As shown, a portion of the surface of the edge mask 22a protrudes upwards in the figure, becoming a pixel light spacer configured as an island.

[0051] like Figure 3 and Figure 6As shown, the sealing film 40 comprises: a first inorganic sealing film 36 disposed to cover the second electrode 24, an organic sealing film 37 disposed on the first inorganic sealing film 36, and a second inorganic sealing film 38 disposed to cover the organic sealing film 37, and has the function of protecting the organic EL layer 23 from the influence of moisture, oxygen, etc. Here, the first inorganic sealing film 36 and the second inorganic sealing film 38 are made of inorganic materials such as silicon nitride (SiNx (x is a positive number)) such as silicon oxide (SiO2), aluminum oxide (Al2O3), silicon tetranitride (Si3N), and silicon carbonitride (SiCN). In addition, the organic sealing film 37 is made of organic materials such as acrylic resin, polyurea resin, parylene resin, polyimide resin, and polyamide resin.

[0052] In addition, such as Figure 1 As shown, the organic EL display device 50 has the following in the bezel area F: a first barrier wall Wa, which is arranged in a frame shape to overlap with the peripheral end of the organic sealing film 37 in a manner that surrounds the display area D; and a second barrier wall Wb, which is arranged in a frame shape to surround the first barrier wall Wa.

[0053] like Figure 6 As shown, the first barrier wall Wa includes: a lower resin layer 19b formed on the same layer as the planarization film 19a; an upper resin layer 22c formed on the lower resin layer 19b on the same layer as the edge cover 22a; and a metal layer 21b disposed between the lower resin layer 19b and the upper resin layer 22c. Here, as Figure 6 As shown, the metal layer 21b is configured in a generally C-shape in the frame region F, overlapping with the trench G, the first barrier wall Wa, and the second barrier wall Wb. Furthermore, the metal layer 21b is formed in the same layer using the same material as the first electrode 21a.

[0054] like Figure 6 As shown, the second barrier wall Wb includes: a lower resin layer 19c formed on the same layer as the planarization film 19a; an upper resin layer 22d disposed on the lower resin layer 19c and formed on the same layer as the edge cover 22a; and a metal layer 21b disposed between the lower resin layer 19c and the upper resin layer 22d.

[0055] In addition, such as Figure 1As shown, the organic EL display device 50 has a first bezel wiring 18h in the bezel region F. This wiring extends wider at the opening of the trench G, extends linearly inside the trench G on the display region D side, and extends to the terminal portion T at both ends opposite to the display region D. Here, the first bezel wiring 18h is configured to be electrically connected to the power line 18g on the display region D side of the bezel region F, and a high power supply voltage (ELVDD) is input at the terminal portion T. Furthermore, the first bezel wiring 18h and the second bezel wiring 18i (described later) are formed in the same layer using the same material as the source line 18f and the power line 18g.

[0056] In addition, such as Figure 1 As shown, the organic EL display device 50 has a second bezel wiring 18i in the bezel region F, which is arranged in a generally C-shape outside the groove G, overlapping the first barrier wall Wa and the second barrier wall Wb, and extending to the terminal portion T at both ends. Here, as Figure 6 As shown, the second border wiring 18i is configured to be electrically connected to the second electrode 24 via the metal layer 21b formed in the trench G, and a low power supply voltage (ELVSS) is input at the terminal portion T.

[0057] In addition, such as Figure 3 and Figure 6 As shown, the organic EL display device 50 has peripheral light spacers S in the bezel area F that protrude upwards as shown in the figure. Here, as... Figure 3 and Figure 6 As shown, the peripheral light spacer S comprises: a lower resin layer 19d formed on the same layer as the planarization film 19a; a plurality of upper resin layers 22b disposed on the lower resin layer 19d and formed on the same layer as the edge mask 22a; and a metal layer 21b disposed between the lower resin layer 19d and each of the upper resin layers 22b.

[0058] The organic EL display device 50 is configured such that, in each sub-pixel P, a gate signal is input to the first TFT 9a through the gate line 14g, making the first TFT 9a in a conducting state; a data signal is written to the gate 14b of the second TFT 9b and the capacitor 9c through the source line 18f; and a current from the power line 18g, corresponding to the gate voltage of the second TFT 9b, is supplied to the organic EL layer 23 of the organic EL element 25, causing the light-emitting layer 3 of the organic EL layer 23 to emit light and display an image. Furthermore, in the organic EL display device 50, even if the first TFT 9a is in a cutoff state, the gate voltage of the second TFT 9b is maintained by the capacitor 9c, thus maintaining the emission of the light-emitting layer 3 until the gate signal for the next frame is input.

[0059] Next, a method for manufacturing the organic EL display device 50 of the present embodiment will be described. In addition, the method for manufacturing the organic EL display device 50 of the present embodiment includes: a TFT layer forming step; an organic EL element layer forming step, which includes a first electrode forming step, an edge mask forming step, an organic EL layer forming step, and a second electrode forming step; and a sealing film forming step. Here, Figure 7 is a cross-sectional view schematically showing a resin coating material forming step of the edge mask forming step in the organic EL element layer process. In addition, Figure 8 is a cross-sectional view schematically showing the Figure 7 virtual electrode removing step of the subsequent edge mask forming step. In addition, Figure 9 is a cross-sectional view schematically showing the Figure 8 ashing step of the subsequent edge mask forming step.

[0060] <TFT layer forming step>

[0061] First, a bottom coating film 11, a first TFT 9a, a second TFT 9b, a capacitor 9c, and a planarization film 19a are formed on the surface of the resin substrate layer 10 formed on a glass substrate by a known method to form a TFT layer 20.

[0062] <Organic EL element layer forming step (light-emitting element layer forming step)>

[0063] First, on the planarization film 19a of the TFT layer 20 formed in the TFT layer forming step, a metal reflective film such as a silver film is formed by, for example, sputtering, and then the metal reflective film is subjected to photolithography, etching treatment using an etchant containing phosphoric acid, nitric acid, and acetic acid, and resist stripping treatment, so that a plurality of first electrodes 21a are formed in a matrix in the display region D, and a plurality of virtual electrodes 21d are formed in a frame shape surrounding the plurality of first electrodes 21a in the border region F (first electrode forming step). Here, the plurality of virtual electrodes 21d are provided in, for example, multiple columns such as 4 columns. In addition, in the first electrode forming step, the plurality of virtual electrodes 21d are formed such that the pattern density of the plurality of virtual electrodes 21d is the same as the pattern density of the plurality of first electrodes 21a. In addition, for example, if the cross-sectional view of the plurality of virtual electrodes 21d is Figure 3 they are provided on the planarization film 19a in a region overlapping with the first border wiring 18h in the border region F.

[0064] Next, a photosensitive resin film 22 made of polyimide is coated on the surface of the substrate on which the plurality of first electrodes 21a and the plurality of virtual electrodes 21d are formed by, for example, spin coating or slit coating, and then the photosensitive resin film 22 is pre-dried, semi-exposed, developed, and post-dried, so that as Figure 7The resin cover 22e is formed as shown (resin cover forming process / edge cover forming process). Here, as... Figure 7 As shown, the resin cover 22e is provided such that it covers a plurality of first electrodes 21a and exposes a plurality of virtual electrodes 21d. The portion corresponding to the periphery of each first electrode 21a is thinner than the portion corresponding to the periphery of each first electrode 21a. In addition, the resin cover 22e can be formed by exposing the photosensitive resin film 22 by half-exposure using a half-tone mask or a gray-tone mask.

[0065] Then, through etching using an etchant containing phosphoric acid, nitric acid, and acetic acid, such as... Figure 8 As shown, multiple virtual electrodes 21d exposed from the resin cover 22e are removed (virtual electrode removal process / edge cover formation process).

[0066] Furthermore, by utilizing ashing to thin the resin cover 22e, thereby achieving... Figure 9 As shown, edge mask 22a is formed (ashing process / edge mask forming process).

[0067] Next, an organic EL layer 23 (hole injection layer 1, hole transport layer 2, light-emitting layer 3, electron transport layer 4, electron injection layer 5) is formed on each of the first electrodes 21a exposed from the edge cover 22a by, for example, vacuum evaporation (organic EL layer formation process (light-emitting functional layer formation process)).

[0068] Finally, the ITO film is formed by, for example, vacuum evaporation to cover each organic EL layer 23 and the edge mask, to form the second electrode 24 (second electrode formation process).

[0069] As described above, an organic EL element layer 30 can be formed.

[0070] <Sealing film formation process>

[0071] First, on the surface of the substrate on which the organic EL element layer 30 is formed in the organic EL element layer formation process, an inorganic insulating film such as a silicon nitride film, a silicon oxide film, or a silicon oxynitride film is formed by plasma CVD (chemical vapor deposition) using a mask, thereby forming a first inorganic sealing film 36.

[0072] Next, for example, an organic resin material such as acrylic resin is formed on the surface of the substrate on which the first inorganic sealing film 36 is formed by inkjet printing to form an organic sealing film 37.

[0073] Furthermore, on the substrate surface where the organic sealing film 37 is formed, an inorganic insulating film, such as a silicon nitride film, a silicon oxide film, or a silicon oxynitride film, is formed by plasma CVD using a mask to form a second inorganic sealing film 38, thereby forming a sealing film 40.

[0074] Finally, after attaching a protective sheet (not shown) to the substrate surface on which the sealing film 40 is formed, the glass substrate is peeled off from the lower surface of the resin substrate layer 10 by irradiating a laser from the glass substrate side of the resin substrate layer 10, and then a protective sheet (not shown) is attached to the lower surface of the resin substrate layer 10 after the glass substrate has been peeled off.

[0075] As described above, the organic EL display device 50 of this embodiment can be manufactured.

[0076] Next, an experiment will be described specifically illustrating the manufacturing method of the organic EL display device 50 according to this embodiment. Here, Figure 10 and Figure 11 This is a table showing the experimental results of embodiments and comparative examples of the manufacturing method of the organic EL display device 50.

[0077] Specifically, in this embodiment, a type 2.13 organic EL display device is prototyped using the manufacturing method of the organic EL display device 50 described above. Here, in this embodiment, the design dimensions of the first electrode are set to 39.2 μm x 42.7 μm, and its design spacing is set to 44.0 μm x 49.0 μm. The virtual electrode formed by four columns is the same as the first electrode, with its design dimensions set to 39.2 μm x 42.7 μm and its design spacing set to 44.0 μm x 49.0 μm.

[0078] Furthermore, in the comparative example, the formation of the dummy electrode 21d in the first electrode formation step is omitted. The edge cover 22a is formed in one stage by pre-drying, fully exposing, developing, and post-drying the photosensitive resin film 22 from the resin cover formation step of the edge cover formation step. Additionally, similarly to the embodiment, the first electrode is designed to have dimensions of 39.2µm x 42.7µm, with a design spacing of 44.0µm x 49.0µm.

[0079] Then, in the organic EL display device (panel) prototyped in the embodiments and comparative examples, the longitudinal and lateral dimensions of the first electrode were measured using a laser microscope to evaluate the deviation in the size of the first electrode. Furthermore, regarding the measurement points for size, in a rectangular 2.13-type panel viewed from above, the measurement points are approximately 1 / 4 of the way from the end of one of the long sides (circled number 1 in the outer perimeter of the table), approximately 1 / 2 of the way from the end (circled number 2 in the outer perimeter of the table), and approximately 3 / 4 of the way from the end (circled number 3 in the outer perimeter of the table). The measurement points are also approximately 1 / 4 of the way from the end of the midline located between the two long sides (circled number 1 in the center of the table), approximately 1 / 2 of the way from the end (circled number 2 in the center of the table), and approximately 3 / 4 of the way from the end (circled number 3 in the center of the table).

[0080] As an experimental result, in the embodiments, such as Figure 10 As shown in the table, the difference between the central portion and the outer perimeter is 0.20 μm in the longitudinal direction and 0.24 μm in the transverse direction. In the comparative example, as... Figure 11 As shown in the table, the difference between the central portion and the outer periphery is 1.24 μm in the longitudinal direction and 1.41 μm in the transverse direction. Therefore, in the embodiment, the difference between the central portion and the outer periphery is 16.1% of that in the comparative example in the longitudinal direction and 17.0% of that in the comparative example in the transverse direction, confirming the improvement effect regarding the deviation in the size of the first electrode.

[0081] As described above, according to the manufacturing method of the organic EL display device 50 of this embodiment, in the first electrode forming step, when forming a plurality of first electrodes 21a, a plurality of dummy electrodes 21d made of the same material as each first electrode 21a are formed around the plurality of first electrodes 21a. In the edge cover forming step, the plurality of dummy electrodes 21d are removed before forming the edge cover 22a. Therefore, in the first electrode forming step, a metal reflective film such as a silver film is patterned by etching, thereby forming a plurality of first electrodes 21a in a matrix shape on the display area D, and forming a plurality of dummy electrodes 21d in a frame shape around the plurality of first electrodes 21a. Here, in the first electrode forming step, when etching the metal reflective film, the etching rate varies due to the difference in pattern density. However, the outermost pattern forming layer is not the first electrode 21a on the outer periphery, but the dummy electrodes 21d around it. Therefore, the size difference between the first electrode 21a in the central part and the first electrode 21a on the outer periphery, where the difference in pattern density is relatively small, is smaller than the size difference between the first electrode 21a in the central part and the dummy electrodes 21d, where the difference in pattern density is relatively large. Furthermore, if the difference in pattern density increases, the difference in etching rate increases; conversely, if the difference in pattern density decreases, the difference in etching rate tends to decrease. Therefore, in the display area D, the difference in etching rate between the first electrode 21a in the central portion and the first electrode 21a in the outer periphery decreases. This suppresses deviations in the size of the first electrode 21a disposed in the display area D, inhibits the generation of display unevenness, and ensures display quality.

[0082] Furthermore, according to the manufacturing method of the organic EL display device 50 of this embodiment, the edge cover forming process includes: exposing the photosensitive resin film 22 with half exposure to cover a plurality of first electrodes 21a, forming a resin cover 22e that is thinner than the portion corresponding to the peripheral end of each first electrode 21a; removing a plurality of virtual electrodes 21d exposed from the resin cover 22a; and thinning the resin cover 22e by ashing to form the edge cover 22a. Thus, the resin cover 22e is formed without adding a photomask, and the resin cover 22e is transformed to form the edge cover 22a, thereby enabling the manufacture of an organic EL display device 50 that suppresses the size deviation of the first electrodes 21a at low cost.

[0083] Other Implementation Methods

[0084] In the various embodiments described, an organic EL layer with a five-layer stacked structure of a hole injection layer, a hole transport layer, a light emission layer, an electron transport layer, and an electron injection layer is shown. However, the organic EL layer may also be a three-layer stacked structure of a hole injection layer that also serves as a hole transport layer, a light emission layer, and an electron transport layer that also serves as an electron injection layer.

[0085] Furthermore, in the various embodiments described, an organic EL display device is illustrated with the first electrode as the anode and the second electrode as the cathode. However, the present invention is also applicable to organic EL display devices in which the stacked structure of the organic EL layer is reversed, with the first electrode as the cathode and the second electrode as the anode.

[0086] Furthermore, while the embodiments described herein illustrate an organic EL display device in which the electrode of the TFT connected to the first electrode is used as the drain, the present invention is also applicable to organic EL display devices in which the electrode of the TFT connected to the first electrode is used as the source.

[0087] Furthermore, while organic EL display devices are exemplified as display devices in the various embodiments described, the present invention can also be applied to display devices such as liquid crystal display devices with active matrix driving.

[0088] Furthermore, while organic EL display devices have been described as examples of display devices in the various embodiments, the present invention can be applied to display devices having multiple light-emitting elements driven by current, such as display devices having light-emitting elements having a layer of quantum dots, i.e., QLED (Quantum-dot light emitting diode).

[0089] Industrial availability

[0090] As described above, the present invention is useful for flexible display devices.

[0091] Explanation of reference numerals in the attached figures

[0092] D: Display area;

[0093] F: Border area;

[0094] P: Subpixel;

[0095] S: Peripheral light spacers;

[0096] Wa: First barrier wall;

[0097] Wb: Second barrier wall;

[0098] 10: Resin substrate layer (base substrate);

[0099] 19a: Planarization film;

[0100] 19b, 19c, 19d: Lower resin layer;

[0101] 20: TFT layer (thin-film transistor layer);

[0102] 21a: First electrode;

[0103] 21b: Metal layer;

[0104] 21d: Virtual electrode;

[0105] 22: Photosensitive resin film;

[0106] 22a: Edge shield;

[0107] 22b, 22c, 22d: Upper resin layer;

[0108] 22e: Resin covering;

[0109] 23: Organic EL layer (organic electroluminescent layer, light-emitting functional layer);

[0110] 24: Second electrode;

[0111] 30: Organic EL element layer (light-emitting element layer);

[0112] 36: First inorganic sealing membrane;

[0113] 37: Organic sealing film;

[0114] 38: Second inorganic sealing membrane;

[0115] 40: Sealing film;

[0116] 50: Organic EL display device.

Claims

1. A method for manufacturing a display device, comprising: The thin-film transistor layer formation process forms a thin-film transistor layer on a substrate. The light-emitting element layer formation process involves forming a light-emitting element layer on the thin-film transistor layer. The light-emitting element layer corresponds to multiple sub-pixels constituting the display area and is sequentially stacked with multiple first electrodes, multiple light-emitting functional layers, and a common second electrode. The manufacturing method of the display device is characterized in that… The process for forming the light-emitting element layer includes: In the first electrode formation process, the plurality of first electrodes are formed on the thin-film transistor layer; An edge cover forming process is performed to form an edge cover in a manner that covers the peripheral ends of each of the first electrodes; The light-emitting functional layer forming process involves forming each light-emitting functional layer on each of the first electrodes exposed from the edge cover; and The second electrode formation process involves forming the second electrode by covering each of the light-emitting functional layers and the edge mask. In the first electrode forming process, when forming the plurality of first electrodes, a plurality of virtual electrodes made of the same material as each of the first electrodes are formed around the plurality of first electrodes. In the edge cover forming process, the plurality of dummy electrodes are removed before the edge cover is formed.

2. The method for manufacturing a display device according to claim 1, characterized in that, The edge cover forming process includes: In the resin cover forming process, a resin cover is formed that covers the plurality of first electrodes, and the portion of the resin cover other than the peripheral end of each first electrode is thinner than the portion corresponding to the peripheral end of each first electrode. The virtual electrode removal process removes the plurality of virtual electrodes exposed from the resin cover. as well as The ashing process thins the resin covering to form the edge cover.

3. The method for manufacturing a display device according to claim 2, characterized in that, In the resin coating forming process, the resin coating is formed by exposing the photosensitive resin film through semi-exposure.

4. The method for manufacturing a display device according to any one of claims 1 to 3, characterized in that, In the first electrode forming process, the plurality of virtual electrodes are formed into a frame shape in a manner that surrounds the plurality of first electrodes.

5. The method for manufacturing a display device according to claim 4, characterized in that, In the first electrode forming process, the plurality of virtual electrodes are formed into multiple columns.

6. The method for manufacturing a display device according to claim 4, characterized in that, In the first electrode forming process, the plurality of virtual electrodes are formed in such a manner that the pattern density of the plurality of virtual electrodes is the same as the pattern density of the plurality of first electrodes.

7. A method for manufacturing a display device according to any one of claims 1 to 3, characterized in that, The process includes a sealing film formation process after the light-emitting element layer formation process, in which a sealing film is formed on the light-emitting element layer, wherein the sealing film consists of a first inorganic sealing film, an organic sealing film, and a second inorganic sealing film stacked sequentially.

8. The method for manufacturing a display device according to claim 7, characterized in that, A border area is provided around the display area. The thin-film transistor layer is located in the display area, and a planarization film is disposed on the side of the light-emitting element layer. In the border area, a first barrier wall is provided in a manner that overlaps with the peripheral end of the organic sealing film in order to surround the display area, and a second barrier wall is provided in a manner that surrounds the first barrier wall. The first barrier wall and the second barrier wall include: The lower resin layer is formed in the same layer as the planarization film; The upper resin layer, which is formed in the same layer of the same material as the edge cover; and A metal layer, formed in the same layer as the first electrodes, is located between the lower resin layer and the upper resin layer.

9. The method for manufacturing a display device according to claim 8, characterized in that, A light spacer is provided on the display area side of the first blocking wall in the frame area. The optical spacer includes: The lower resin layer is formed in the same layer as the planarization film; The upper resin layer, which is formed in the same layer of the same material as the edge cover; and A metal layer, formed in the same layer as the first electrodes, is located between the lower resin layer and the upper resin layer.

10. A method for manufacturing a display device according to any one of claims 1 to 3, characterized in that, Each of the light-emitting functional layers is an organic electroluminescent layer.

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