METHOD FOR MANUFACTURING DISPLAY DEVICE BY UV-CURING ORGANIC LAYER OF SEALING FILM
20190363293 ยท 2019-11-28
Inventors
- Akihiro MATSUI (Sakai City, JP)
- Jumpei TAKAHASHI (Sakai City, JP)
- TOHRU SENOO (Sakai City, JP)
- TAKESHI HIRASE (Sakai City, JP)
- TOHRU SONODA (Sakai City, JP)
- TAKASHI OCHI (Sakai City, JP)
- Hisao OCHI (Sakai City, JP)
Cpc classification
H10K71/00
ELECTRICITY
H10K71/40
ELECTRICITY
Y02P70/50
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
H10K59/8731
ELECTRICITY
H10K50/8445
ELECTRICITY
H05B33/10
ELECTRICITY
B05D1/60
PERFORMING OPERATIONS; TRANSPORTING
G09F9/30
PHYSICS
International classification
Abstract
Provided is a method for manufacturing an organic EL display device, including forming a sealing film to cover an organic EL element. The forming a sealing film includes forming a first inorganic layer to cover the organic EL element, forming a partition on the first inorganic layer, forming an organic layer on the first inorganic layer by applying an organic material inward from the partition on a surface of the first inorganic layer, removing the partition, and forming a second inorganic layer on the first inorganic layer to cover the organic layer.
Claims
1-4. (canceled)
5. A method for manufacturing a display device, the method comprising: forming a light emitting element on a base substrate; and forming a sealing film to cover the light emitting element, wherein the forming a sealing film includes fixing a mask including a larger opening than a display region on the base substrate, forming a first inorganic layer inside the mask to cover the light emitting element, forming an organic layer on the first inorganic layer by applying an organic material inside the first inorganic layer on a surface of the first inorganic layer by use of the mask, removing the mask from the base substrate, forming a second inorganic layer on the first inorganic layer to cover the organic layer, and during the forming an organic layer, the organic layer is cured by UV irradiation with the mask being provided on the base substrate.
6. The method for manufacturing a display device according to claim 5, wherein the mask includes a recessed portion on a side facing the organic layer.
7. The method for manufacturing a display device according to claim 6, wherein during the forming an organic layer, a cavity in which the organic layer is not formed is provided inside the recessed portion on the first inorganic layer to form the organic layer inside the first inorganic layer in a plan view.
8. (canceled)
9. The method for manufacturing a display device according to claim 5, wherein the light emitting element is an organic EL element.
10. The method for manufacturing a display device according to claim 5, wherein the base substrate is flexible.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0009]
[0010]
[0011]
[0012]
[0013]
[0014]
[0015]
[0016]
[0017]
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[0019]
[0020]
DESCRIPTION OF EMBODIMENTS
[0021] Embodiments of the disclosure will be described below in detail with reference to the drawings. The disclosure is not limited to the embodiments described below.
First Embodiment
[0022]
[0023] As illustrated in
[0024] As illustrated in
[0025] As illustrated in
[0026] The base substrate 10 is a plastic substrate including a polyimide resin, for example. In the present embodiment, the illustrated example of the base substrate is a flexible and insulating transparent resin substrate, but the base substrate may be an insulating transparent glass substrate or an electrically conductive opaque metal sheet, for example.
[0027] As illustrated in
[0028] As illustrated in
[0029] As illustrated in
[0030] The organic EL element 18 is disposed over the display region D. As illustrated in
[0031] As illustrated in
[0032] As illustrated in
[0033] As illustrated in
[0034] The hole injecting layer 31 is also referred to as an anode organic layer and has functions to reduce the energy level difference between the first electrode 14 and the organic EL layer 16 to improve the efficiency of hole injection into the organic EL layer 16 from the first electrode 14. Examples of materials that may be included in the hole injecting layer 31 include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, phenylenediamine derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, and stilbene derivatives.
[0035] The hole transport layer 32 functions to improve the efficiency of hole transport from the first electrode 14 to the organic EL layer 16. Examples of materials that may be included in the hole transport layer 32 include porphyrin derivatives, aromatic tertiary amine compounds, styrylamine derivatives, polyvinylcarbazole, poly-p-phenylenevinylene, polysilane, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amine-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, hydrogenated amorphous silicon, hydrogenated amorphous silicon carbide, zinc sulfide, and zinc selenide.
[0036] The light emitting layer 33 is a region where the holes and the electrons recombine, when a voltage is applied via the first electrode 14 and the second electrode 17, holes and electrons are injected from the first electrode 14 and the second electrode 17, respectively. The light emitting layer 33 includes a material having a high light emitting efficiency. Examples of materials that may be included in the light emitting layer 33 include metal oxinoid compounds (8-hydroxyquinoline metal complexes), naphthalene derivatives, anthracene derivatives, diphenyl ethylene derivatives, vinyl acetone derivatives, triphenylamine derivatives, butadiene derivatives, coumarin derivatives, benzoxazole derivatives, oxadiazole derivatives, oxazole derivatives, benzimidazole derivatives, thiadiazole derivatives, benzothiazole derivatives, styryl derivatives, styrylamine derivatives, bisstyrylbenzene derivatives, trisstyrylbenzene derivatives, perylene derivatives, perinone derivatives, aminopyrene derivatives, pyridine derivatives, rhodamine derivatives, aquidine derivatives, phenoxazone, quinacridone derivatives, rubrene, poly-p-phenylenevinylene, and polysilane.
[0037] The electron transport layer 34 functions to facilitate migration of the electrons to the light emitting layer 33 efficiently. Examples of materials that may be included in the electron transport layer 34 include organic compounds, the examples of which include oxadiazole derivatives, triazole derivatives, benzoquinone derivatives, naphthoquinone derivatives, anthraquinone derivatives, tetracyanoanthraquinodimethane derivatives, diphenoquinone derivatives, fluorenone derivatives, silole derivatives, and metal oxinoid compounds.
[0038] The electron injecting layer 35 functions to reduce the energy level difference between the second electrode 17 and the organic EL layer 16, to improve the efficiency of electron injection into the organic EL layer 16 from the second electrode 17. By this function, the driving voltage for the organic EL element 18 can be reduced. Note that the electron injection layer 35 is also referred to as a cathode organic layer. Examples of materials that constitute the electron injection layer 35 include inorganic alkaline compounds such as lithium fluoride (LiF), magnesium fluoride (MgF.sub.2), calcium fluoride (CaF.sub.2), strontium fluoride (SrF.sub.2), and barium fluoride (BaF.sub.2); aluminum oxide (Al.sub.2O.sub.3), and, strontium oxide (SrO).
[0039] As illustrated in
[0040] Examples of materials that may be included in the second electrode 17 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). Further the second electrode 17 may be formed of alloys such as (Mg)-copper (Cu), magnesium (Mg)-silver (Ag), sodium (Na)-potassium (K), astatine (At)-astatine oxide (AtO.sub.2), lithium (Li)-aluminum (Al), lithium (Li)-calcium (Ca)-aluminum (Al), and lithium fluoride (LiF)-calcium (Ca)-aluminum (Al), for example. Further examples of materials that may be included in the second electrode 17 include electrically conductive oxides, the examples of which include tin oxide (SnO), zinc oxide (ZnO), indium tin oxide (ITO), and indium zinc oxide (IZO). The second electrode 17 may include a stack of two or more layers of any of the above-mentioned materials. Examples of materials having a small work function include 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), and lithium fluoride (LiF)-calcium (Ca)-aluminum (Al).
[0041] The sealing film 25 is disposed over the display region D and the non-display region N, and covers the organic EL element 18. The sealing film 25 functions to protect the organic EL element 18 from moisture and oxygen. As illustrated in
[0042] More specifically, the sealing film 25 is disposed on the surface of the organic EL element 18, and includes the first inorganic layer 19, the organic layer 20, and the second inorganic layer 21. The first inorganic layer 19 includes a first inorganic film. The organic layer 20 includes an organic film and is disposed on the surface of the first inorganic layer 19. The second inorganic layer 21 includes a second inorganic film and is disposed on the surface of the organic layer 20.
[0043] As illustrated in
[0044] As illustrated in
[0045] The organic layer 20 is formed of an organic film such as acrylate, polyurea, parylene, polyimide, or polyamide. As illustrated in
[0046] The organic EL display device 1, configured as described above, is flexible. In each of the subpixels, the light emitting layer 33 of the organic EL layer 16 is configured to emit light via the TFT 12 appropriately so that images can be displayed.
[0047] Next, a method for manufacturing the organic EL display device according to the present embodiment will be described.
[0048] The organic EL display device 1 according to the present embodiment can be produced in the following manner, for example. First, as illustrated in
[0049] Next, as illustrated in
[0050] Next, the first inorganic layer 19 is formed to cover the organic EL element 18. More specifically, first, silicon oxide is stacked over the surfaces of the base substrate 10 and the organic EL element 18 by using, for example, a plasma CVD method with a mask, a sputtering method, or an atomic layer deposition method (ALD method). Thus, the silicon oxide layer 19a is formed to cover the surface of the organic EL element 18, as illustrated in
[0051] Next, as with the silicon oxide layer 19a described above, silicon nitride is stacked on the surface of the silicon oxide layer 19a by using, for example, a plasma CVD method with a mask, a sputtering method, or an atomic layer deposition method (ALD method). Thus, the silicon nitride layer 19b is formed on the base substrate by use of a mask having a larger opening than the display region D to cover the surface of the organic EL element 18, as illustrated in
[0052] Next, as illustrated in
[0053] Moreover, in a case of using a metal mask for the partition 30, a magnet member (not illustrated) having a magnetic force is provided on a surface of the base substrate 10, opposite to the side on which the partition 30 is provided, so that the magnetic force of the magnet member allows the partition 30 to be secured on the first inorganic layer 19.
[0054] Next, an organic material is stacked on the surface 26 of the silicon nitride layer 19b and inside the partition 30 (i.e., a formation region of the organic layer 20 illustrated in
[0055] Here, the partition 30 thus provided on the first inorganic layer 19 restricts spreading of an organic material applied at the time of forming the organic layer 20.
[0056] Further, as illustrated in
[0057] Specifically, as illustrated in
[0058] Next, after the organic layer 20 is cured, the partition 30 is removed from the surface of the first inorganic layer 19. For example, in a case of using the metal mask for the partition 30, the organic material is cured by heating, and then the base substrate 10 and the partition 30 are cooled so that the partition 30 can be separated and removed from the surface of the first inorganic layer 19.
[0059] Next, the second inorganic layer 21 is formed on the first inorganic layer 19 to cover the organic layer 20. More specifically, first, silicon oxide is stacked over the surface of the organic layer 20 by using, for example, a plasma CVD method with a mask, a sputtering method, or an atomic layer deposition method (ALD method). Thus, the silicon oxide layer 21a is formed to cover the surface of the organic layer 20, as illustrated in
[0060] Next, as with the silicon oxide layer 21a described above, silicon nitride is stacked on the surface of the silicon oxide layer 21a by using, for example, a plasma CVD method with a mask, a sputtering method, or an atomic layer deposition method (ALD method). Thus, the silicon nitride layer 21b is formed to cover the surface of the organic layer 20, as illustrated in
[0061] The organic EL display device 1 of the present embodiment can be manufactured as described above.
[0062] The method for manufacturing the organic EL display device 1 of the present embodiment described above produces the following effects (1) and (2).
[0063] (1) After the partition 30 is formed on the first inorganic layer 19, an organic material is applied inward from the partition 30 on the surface of the first inorganic layer 19 to form the organic layer 20 on the first inorganic layer 19. After that, the partition 30 is removed. Accordingly, since the known dam wall is not necessary, the frame region N does not need to include the dam wall. As a result, the frame narrowing of the organic EL display device 1 can be performed.
[0064] (2) The partition 30 has the recessed portion 30a on a side facing the organic layer 20. The recessed portion 30a causes a water-repellent function to be provided, and thus the spreading of the organic material is certainly restricted at the time of forming the organic layer 20.
Second Embodiment
[0065] A second embodiment of the disclosure will be described below.
[0066] In a case of manufacturing the organic EL display device 1 according to the embodiment, a mask 45 having a larger opening than the display region D is fixed onto the base substrate. Note that the mask 45 defines a coating region of an organic material for forming the organic layer 20 (i.e., a formation region of the organic layer 20).
[0067] Further, as illustrated in
[0068] In addition, a metal mask is used for the mask 45. As with the partition 30 according to the first embodiment, a magnet member (not illustrated) having magnetic force is provided on a surface of the base substrate 10 opposite to the surface having the mask 45. Thus, the magnetic force of the magnet member retains the mask 45 on the base substrate 10.
[0069] More specifically, first, silicon oxide is stacked on the surfaces of the base substrate 10 and the organic EL element 18 by using, for example, a plasma CVD method, a sputtering method, or an atomic layer deposition method (ALD method) using the mask 45. Thus, the silicon oxide layer 19a is formed to cover the surface of the organic EL element 18, as illustrated in
[0070] Next, as with the silicon oxide layer 19a described above, silicon nitride is stacked on the surface of the silicon oxide layer 19a by using, for example, a plasma CVD method, a sputtering method, or an atomic layer deposition method (ALD method) using the mask 45. Thus, the silicon nitride layer 19b is formed to cover the surface of the organic EL element 18, as illustrated in
[0071] Next, an organic material is applied inward from the edges of the first inorganic layer 19 (i.e., a formation region of the organic layer 20 illustrated in
[0072] Examples of the organic material include acrylate, polyurea, parylene, polyimide, and polyamide. Thus, the organic layer 20 formed of the organic film is formed on the surface 26 of the silicon nitride layer 19b, as illustrated in
[0073] Here, as with the partition 30 of the first embodiment, a cavity in which the organic layer 20 is not formed is provided inside the recessed portion 45a on the first inorganic layer 19 in a process for forming the organic layer 20 as illustrated in
[0074] Note that after the organic material is applied, the organic layer 20 is provisionally cured by UV irradiation, with the mask 45 that functions as a partition being provided. After that, the organic layer 20 is baked at approximately 70 to 100 C. and thus completely cured. Alternatively, preheating, which is executed at the time of forming the second inorganic layer 21 by using a CVD method described below, can replace such baking.
[0075] Next, after the organic layer 20 is cured, the mask 45 is removed from the surface of the base substrate 10.
[0076] Next, as with the first embodiment, the second inorganic layer 21 including the silicon oxide layer 21a and the silicon nitride layer 21b is formed on the first inorganic layer 19 to cover the organic layer 20, thus forming the sealing film 25 including the first inorganic layer 19, the organic layer 20, and the second inorganic layer 21.
[0077] The organic EL display device 1 according to the present embodiment can be manufactured as described above.
[0078] The manufacturing method for the organic EL display device 1 according to the present embodiment described above produces the following effect (3) in addition to the effects (1) and (2) described above.
[0079] (3) The mask 45 used for forming the first inorganic layer 19 is also used as a partition at the time of forming the organic layer 20. This simplifies the process for manufacturing the organic layer 20 and saves costs.
[0080] Note that the embodiments described above can be modified as follows.
[0081] As illustrated in
[0082] In the embodiments described above, the metal mask made of, for example, SUS is used for the partition 30. However, the partition 30 can be also formed by patterning a photosensitive organic resin material by use of a gray tone mask or a half-tone mask.
[0083] Moreover, the mask used for forming the second inorganic layer 21 can be also disposed outward from the partition 30 or the mask 45 (outward in the width direction Y of the organic EL display device 1 illustrated in
[0084] In the embodiments described above, the example of the organic EL layer is given that has the five-layer structure including the hole injection layer, the hole transport layer, the light emitting layer, the electron transport layer, and the electron injection layer. The organic EL layer may have, for example, a three-layer structure including a hole injection-cum-transport layer, a light emitting layer, and an electron transport-cum-injection layer.
[0085] In the embodiments described above, the example of the organic EL display device is given that includes the first electrode as an anode and the second electrode as a cathode. However, the disclosure is also applicable to an organic EL display device, in which the layered structure of the organic EL layer is reversed, with the first electrode being a cathode and the second electrode being an anode.
[0086] In the embodiments described above, the example of the organic EL display device is given that includes the element substrate in which the electrode of the TFT connected to the first electrode is the drain electrode. However, the disclosure is also applicable to an organic EL display device including an element substrate in which the electrode of the TFT connected to the first electrode is referred to as the source electrode.
[0087] In the embodiments described above, organic EL display devices are described as display devices by way of example. The disclosure is also applicable to display devices including a plurality of electro-optical elements that are driven by an electrical current. For example, the disclosure is applicable to display devices including quantum dot light emitting diodes (QLEDs), which are light emitting elements using a quantum dot-containing layer.
INDUSTRIAL APPLICABILITY
[0088] As described above, the disclosure is useful for manufacturing methods for organic EL display devices.
REFERENCE SIGNS LIST
[0089] 1 Organic EL display device [0090] 10 Base substrate [0091] 11 Base coating film [0092] 12 TFT [0093] 13 Interlayer insulating film [0094] 16 Organic EL layer [0095] 18 Organic EL element [0096] 19 First inorganic layer [0097] 20 Organic layer [0098] 21 Second inorganic layer [0099] 25 Sealing film [0100] 30 Partition [0101] 30A Recessed portion [0102] 40 Teflon coating layer [0103] 45 Mask