Patent Application
20230309362
The present invention relates to a display device and a manufacturing method thereof.
In recent years, light-emitting organic electroluminescence (EL) display devices using organic EL elements are drawing attention as a replacement for liquid crystal display devices. Among these organic EL display devices, a flexible organic EL display device is proposed. In the organic EL display device, such components as organic EL devices are formed on a flexible resin substrate layer. Here, the organic EL display device includes a frame region provided around a display region that displays an image. This frame region is requested to be reduced in area; that is, to be formed narrower. Then, as to the flexible organic EL display device, when the frame region is folded, and an area occupied with the frame region is reduced in plan view, wires arranged in the frame region could break.
For example, Patent Document 1 discloses a flexible display device. In the flexible display device, a bending hole is formed to partially remove each of a buffer film, a gate insulating film, and an interlayer insulating film, all of which correspond to a bending region. Thus, the bending hole keeps wires from breaking.
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2014-232300
In the flexible organic EL display device, such inorganic insulating films as a base coat film, a gate insulating film, and an interlayer insulating film are provided on a resin substrate layer. Hence, in order to reduce breaks of a plurality of routed wires arranged in the frame region, a structure is proposed as follows: The inorganic insulating films are partially removed from a portion of the frame region to be folded (a folding portion of the frame region). In the removed portion, a filling film is formed. On the filling film, the routed wires are formed. Here, the proposed structure includes: a planarization resin film provided on the plurality of routed wires to protect each of the routed wires; and a reinforcing resin film provided on the planarization resin film to reinforce the folding portion. In a mounting step, for example, the reinforcing resin film is supplied and formed, using such an apparatus as a dispenser apparatus. The reinforcing resin film spreads out, which makes it difficult to form the frame region narrower. That is why the structure has room for improvement.
In view of the above problems, the present invention is intended to form a frame region of a display device narrower even if a reinforcing resin film is provided on a routed wire of a folding portion.
In order to achieve the above object, a display device according to the present invention includes: a resin substrate layer; a thin-film transistor layer provided on the resin substrate layer and including an inorganic insulating film; a light-emitting-element layer provided on the thin-film transistor layer and including a plurality of first electrodes, a plurality of light-emitting functional layers, and a second electrode stacked on top of another in a stated order, each of the plurality of first electrodes and each of the plurality of light-emitting functional layers corresponding to one of a plurality of sub-pixels included in a display region, and the second electrode being provided in common among the plurality of sub-pixels; a frame region provided around the display region; a terminal unit provided to an end portion of the frame region; a folding portion provided between the display region and the terminal unit to extend in a direction; a slit included in the inorganic insulating film and provided to the folding portion to extend in the direction in which the folding portion extends; a filling resin film provided to the folding portion to fill the slit; a plurality of routed wires provided on the filling resin film to extend in parallel with one another in the direction in which the folding portion extends; and a reinforcing resin film provided in the folding portion, the reinforcing resin film being shaped into a strip, being provided on the plurality of routed wires, and extending in the direction in which the folding portion extends, wherein the reinforcing resin film is provided with a first dam wall toward the display region, the first dam wall being in contact with the reinforcing resin film and extending in the direction in which the folding portion extends, and the reinforcing resin film is provided with a second dam wall toward the terminal unit, the second dam wall being in contact with the reinforcing resin film and extending in the direction in which the folding portion extends.
Moreover, a method of manufacturing a display device according to the present invention includes: a thin-film transistor layer forming step of forming, on a resin substrate layer, a thin-film transistor layer including an inorganic insulating film; a light-emitting-element layer forming step of forming, on the thin-film transistor layer, a light-emitting element layer including a plurality of first electrodes, a plurality of light-emitting functional layers, and a second electrode stacked on top of another in a stated order, each of the plurality of first electrodes and each of the plurality of light-emitting functional layers corresponding to one of a plurality of sub-pixels included in a display region, and the second electrode being provided in common among the plurality of sub-pixels; and a sealing film forming step of forming, on the light-emitting element layer, a sealing film including a first inorganic sealing film, an organic sealing film, and a second inorganic sealing film stacked on top of another in a stated order, the display device including: a frame region provided around the display region; a terminal unit provided to an end portion of the frame region; a folding portion provided between the display region and the terminal unit to extend in a direction; a first frame dam wall provided in the frame region, surrounding the display region, and shaped into a frame to overlap with a peripheral end portion of the organic sealing film; and a second frame dam wall shaped into a frame and provided around the first frame dam wall, wherein the thin-film transistor layer forming step includes: a slit forming step of forming a slit provided to the folding portion to extend in the direction in which the folding portion extends; a filling resin film forming step of forming a filling resin film to fill the slit; and a routed wire forming step of forming a plurality of routed wires provided on the filling resin film to extend in parallel with one another in the direction in which the folding portion extends, the thin-film transistor layer forming step and the light-emitting-element layer forming step include a folding dam wall forming step of forming a folding dam wall shaped into a rectangular frame having a pair of long sides extending in the direction in which the folding portion extends, the long sides sandwiching the folding portion, and when the organic sealing film is formed in an interior of the first frame dam wall, the sealing film forming step forms a reinforcing resin film on the plurality of routed wires behind the folding dam wall, the reinforcing resin film being shaped into a strip.
According to the present invention, the reinforcing resin film is provided with the first dam wall toward the display region. The first dam wall is in contact with the reinforcing resin film, and extends in the direction in which the folding portion extends. Moreover, the reinforcing resin film is provided with the second dam wall toward the terminal unit. The second dam wall is in contact with the reinforcing resin film, and extends in the direction in which the folding portion extends. Such features make it possible to form the frame region of the display device narrower even if the reinforcing resin film is provided on the routed wires of the folding portion.
Described below in derail are embodiments of the present invention, with reference to the drawings. Note that the present invention shall not be limited to the embodiments below.
As illustrated in
As illustrated in
In
As illustrated in
The resin substrate layer 10 is made of, for example, polyimide resin.
As illustrated in
As illustrated in
As illustrated in
Note that, as an example, the first TFTs 9a and the second TFTs 9b in this embodiment are top gate TFTs. Alternatively, the first TFTs 9a and the second TFTs 9b may be bottom gate TFTs.
As illustrated in
The planarization resin film 19a has a flat surface in the display region D. The planarization resin film 19a is made of such an organic resin material as, for example, polyimide resin, acrylic resin, or polysiloxane resin.
As illustrated in
The plurality of first electrodes 31a illustrated in
The edge cover 32a illustrated in
The plurality of organic EL layers 33 illustrated in
The hole injection layer 1, also referred to as an anode buffer layer, is capable of approximating the energy levels of the first electrode 31a and the organic EL layer 33, and of increasing efficiency in injection of the holes from the first electrode 31a to the organic EL layer 33. Exemplary materials of the hole injection layer 1 may include a triazole derivative, an oxadiazole derivative, an imidazole derivative, a polyarylalkane derivative, a pyrazoline derivative, a phenylenediamine derivative, an oxazole derivative, a styrylanthracene derivative, a fluorenone derivative, a hydrazone derivative, and a stilbene derivative.
The hole-transport layer 2 is capable of improving efficiency in transporting the holes from the first electrode 31a to the organic EL layer 33. Here, exemplary materials of the hole transport-layer 2 may include a porphyrin derivative, an aromatic tertiary amine compound, a styryl amine derivative, polyvinylcarbazole, poly-p-phenylene vinylene, polysilane, a triazole derivative, an oxadiazole derivative, an imidazole derivative, a polyarylalkane derivative, a pyrazoline derivative, a pyrazolone derivative, a phenylenediamine derivative, an arylamine derivative, an amine-substituted chalcone derivative, an oxazole derivative, a styrylanthracene derivative, a fluorenone derivative, a hydrazone derivative, a stilbene derivative, hydrogenated amorphous silicon, hydrogenated amorphous silicon carbide, zinc sulfide, and zinc selenide.
The light-emitting layer 3 is a region into which the holes and the electrons are injected from the first electrode 31a and the second electrode 34, and in which the holes and the electrons recombine together, when a voltage is applied by the first electrode 31a and the second electrode 34. Here, the light-emitting layer 3 is formed of a material with high light emission efficiency. Exemplary materials of the light-emitting layer 3 may include a metal oxinoid compound [an 8-hydroxyquinoline metal complex], a naphthalene derivative, an anthracene derivative, a diphenylethylene derivative, a vinylacetone derivative, a triphenylamine derivative, a butadiene derivative, a coumarin derivative, a benzoxazole derivative, an oxadiazole derivative, an oxazole derivative, a benzimidazole derivative, a thiadiazole derivative, a benzothiazole derivative, a styryl derivative, a styrylamine derivative, a bisstyrylbenzene derivative, a trisstyrylbenzene derivative, a perylene derivative, a perinone derivative, an aminopyrene derivative, a pyridine derivative, a rodamine derivative, an acridine derivative, phenoxazone, a quinacridone derivative, rubrene, poly-P-phenylene vinylene, and polysilane.
The electron-transport layer 4 is capable of efficiently transporting the electrons to the light-emitting layer 3. Exemplary materials of the electron-transport layer 4 include, as organic compounds, for example, an oxadiazole derivative, a triazole derivative, a benzoquinone derivative, a naphthoquinone derivative, an anthraquinone derivative, a tetracyanoanthraquinodimethane derivative, a diphenoquinone derivative, a fluorenone derivative, a silole derivative, and a metal oxinoid compound.
The electron-injection layer 5 is capable of approximating the energy levels of the second electrode 34 and the organic EL layer 33, and increasing efficiency in injection of the electrons from the second electrode 34 to the organic EL layer 33. Such a feature makes it possible to decrease a drive voltage of the organic EL element. Note that the electron-injection layer 5 may also be referred to as a cathode buffer layer. Exemplary materials of the electron-injection layer 5 may include: such inorganic alkaline compounds as lithium fluoride (LiF), magnesium fluoride magnesium fluoride (MgF2), calcium fluoride (CaF2), strontium fluoride (SrF2), and barium fluoride (BaF2); aluminum oxide (Al2O3); and strontium oxide (SrO).
The second electrode 34 is provided on the plurality of organic EL layers 33 in common among the plurality of sub-pixels P. That is, as illustrated in
The sealing film 40 illustrated in
Furthermore, the organic EL display device 50a illustrated in
The first frame dam wall Wa, as illustrated in
The second frame dam wall Wb, as illustrated in
Moreover, as illustrated in
Furthermore, as illustrated in
In addition, as illustrated in
Moreover, as illustrated in
As illustrated in
The filling resin film 8 is made of such an organic resin material as, for example, polyimide resin, acrylic resin, or polysiloxane resin.
The plurality of routed wires 18j are provided to extend in parallel with one another in a direction perpendicular to the direction in which the folding portion B extends. Here, as illustrated in
The reinforcing resin film 37b illustrated in
The folding dam wall Wc illustrated in
Note that this embodiment exemplifies the organic EL display device 50a including the reinforcing resin film 37b on each of the routed wires 18j. Alternatively, this embodiment may present an organic EL display device 50aa including a base resin film 19e provided between each of the routed wires 18j and the reinforcing resin film 37b. Here,
As illustrated in
In addition, this embodiment exemplifies the organic EL display device 50a including the folding dam wall We shaped into a frame. Alternatively, this embodiment may present: an organic EL display device 50ab including a first dam wall Wca and a second dam wall Wcb extending in parallel with each other; and an organic EL display device 50ac including a first dam wall Wcc and a second dam wall Wcd extending in parallel with each other. Here,
The organic EL display device 50ab is the organic EL display device 50a with an upper-right corner portion and a lower-right corner portion in
The organic EL display device 50ac is the organic EL display device 50a with an upper-right corner portion and a lower-right corner portion in
The above organic EL display device 50a displays an image as follows: In each sub-pixel P, a gate signal is input through the gate line 14 to the first TFT 9a. The first TFT 9a turns ON. Through the source line 18f, a data signal is written in the gate electrode 14b of the second TFT 9b and the capacitor 9c. In accordance with a gate voltage of the second TFT 9b, a current is supplied from the power source line 18g to the organic EL layer 33. The supplied current allows the light-emitting layer 3 of the organic EL layer 33 to emit light and display the image. Note that, in the organic EL display device 50a, even if the first TFT 9a turns OFF, the gate voltage of the second TFT 9b is held in the capacitor 9c. Hence, the light-emitting layer 3 keeps emitting light until a gate signal of the next frame is input.
Described next is a method of manufacturing the organic EL display device 50a of this embodiment. Here, the method of manufacturing the organic EL display device 50a of this embodiment includes: a TFT layer forming step, an organic-EL-element layer forming step, and a sealing film forming step.
TFT Layer Forming Step (Thin-Film Transistor Layer Forming Step)
First, on the resin substrate layer 10 formed on, for example, a glass substrate, such an inorganic insulating film (a thickness of approximately 1000 nm) as a silicon oxide film is deposited by, for example, plasma chemical vapor deposition (CVD) to form the base coat film 11.
Then, throughout the substrate on which the base coat film 11 is formed, for example, an amorphous silicon film (a thickness of approximately 50 nm) is deposited by the plasma CVD. The amorphous silicon film is crystalized by such a technique as laser annealing to form a semiconductor film of a polysilicon film. After that, the semiconductor film is patterned to form such a layer as the semiconductor layer 12a.
After that, throughout the substrate on which such a layer as the semiconductor layer 12a is formed, such an inorganic insulating film (approximately 100 nm) as an silicon oxide film is deposited by, for example, the plasma CVD to form the gate insulating film 13 to cover such a layer as the semiconductor layer 12a.
Moreover, throughout the substrate on which the gate insulating film 13 is formed, such films as an aluminum film (a thickness of approximately 350 nm) and a molybdenum nitride film (a thickness of approximately 50 nm) are sequentially deposited by, for example, sputtering. After that, the metal multilayer film of these metals is patterned to form such lines as the gate lines 14.
Then, using such lines as the gate lines 14 as a mask, such a layer as the semiconductor layer 12a is doped with impurity ions. Hence, such a layer as the semiconductor layer 12a is provided with a channel region, a source region, and a drain region.
After that, throughout the substrate including such a layer as the semiconductor layer 12a provided with the channel region, the source region, and the drain region, such an inorganic insulating film (a thickness of approximately 100 nm) as an silicon oxide film is deposited by, for example, the plasma CVD to form the first interlayer insulating film 15.
Moreover, throughout the substrate on which the first interlayer insulating film 15 is formed, such films as an aluminum film (a thickness of approximately 350 nm) and a molybdenum nitride film (a thickness of approximately 50 nm) are sequentially deposited by, for example, sputtering. After that, the metal multilayer film of these metals is patterned to form such a layer as the upper conductive layer 16c.
Then, throughout the substrate on which such a layer as the upper conductive layer 16c is formed, such an inorganic insulating film (a thickness of approximately 500 nm) as an silicon oxide film is deposited by, for example, the plasma CVD to form the second interlayer insulating film 17.
After that, the gate insulating film 13, the first interlayer insulating film 15, and the second interlayer insulating film 17 are patterned, so that contact holes are formed in a monolayer film of the second interlayer insulating film 17, in a multilayer film of the first interlayer insulating film 15 and the second interlayer insulating film 17, and in a multilayer film of the gate insulating film 13, the first interlayer insulating film 15, and the second interlayer insulating film 17.
Moreover, in the folding portion B, a multilayer film of the base coat film 11, the gate insulating film 13, the first interlayer insulating film 15, and the second interlayer insulating film 17 is removed, so that the slit S is formed in the base coat film 11, the gate insulating film 13, the first interlayer insulating film 15, and the second interlayer insulating film 17 (a slit forming step).
Then, throughout the substrate in which the slit S is formed, for example, photosensitive polyimide resin is applied. After that, the applied film is prebaked, exposed to light, developed, and postbaked to form the filling resin film 8 to fill the slit S of the folding portion B (a filling resin film forming step).
After that, throughout the substrate on which the filling resin film 8 is formed, a titanium film (a thickness of approximately 30 nm), an aluminum film (a thickness of approximately 300 nm) and a titanium film (a thickness of approximately 50 nm) are sequentially deposited by, for example, sputtering. After that, the metal multilayer film of these metals is patterned to form such lines as the source lines 18f and the routed wires 18j (a routed wire forming step).
Finally, throughout the substrate on which, for example, the source lines 18f and the routed wires 18j are formed, a polyimide-based photosensitive resin film (a thickness of approximately 2 μm) is applied by, for example, spin-coating or slit-coating. The applied film is prebaked, exposed to light, developed, and postbaked to form the planarization resin film 19a. Here, when the planarization film 19a is formed, the lower resin layer 19b to be included in the first frame dam wall Wa, the lower resin layer 19c to be included in the second frame dam wall Wb, and the lower resin layer 19d to be included in the folding dam wall We are also formed simultaneously (a first folding dam wall forming step).
Through the above steps, the TFT layer 30a can be formed.
Organic-EL-Element Layer Forming Step (Light-Emitting-Element Layer Forming Step)
On the planarization film 19a of the TFT layer 30a formed at the TFT layer forming step, the first electrodes 31a, the edge cover 32a, the organic EL layers 33 (each including the hole-injection layer 1, the hole-transport layer 2, the organic light-emitting layer 3, the electron-transport layer 4, and the electron-injection layer 5), and the second electrode 34 are formed by a known technique to form the organic-EL-element layer 35. Here, in forming the edge cover 32a, a polyimide-based photosensitive resin film (a thickness of approximately 2 μm) is applied by, for example, spin-coating or slit-coating. After that, the applied film is prebaked, exposed to light, developed, and postbaked to form the edge cover 32a and the peripheral photo spacers 32b. In addition, the upper resin layer 32c to be included in the first frame dam wall Wa, the upper resin layer 32d to be included in the second frame dam wall Wb, and the upper resin layer 32e to be included in the folding dam wall We are formed (a second folding dam wall forming step).
Sealing Film Forming Step
First, on the surface of the substrate on which the organic-EL-element layer 35 is formed at the organic-EL-element-layer forming step, an inorganic insulating film such as, for example, a silicon nitride film, a silicon oxide film, or a silicon nitride oxide film is deposited to form the first inorganic sealing film 36 by the plasma CVD using a mask.
Next, on the surface of the substrate on which the first inorganic film 36 is formed, an organic resin material such as acrylic resin is discharged by, for example, ink-jet printing into an interior of each of the first frame dam wall Wa and the folding dam wall We to respectively form the organic sealing film 37a and the reinforcing resin film 37b.
Moreover, on the substrate on which the organic sealing film 37a is formed, an inorganic insulating film such as a silicon nitride film, a silicon oxide film, or a silicon nitride oxide film is deposited to form the second inorganic film 38 by the plasma CVD using a mask. Hence, the sealing film 40 is formed.
Finally, on the surface of the substrate on which the sealing film 40 is formed, a not-shown protective sheet is attached. After that, a laser beam is emitted on the glass substrate of the resin substrate layer 10 to remove the glass substrate from the bottom surface of the resin substrate layer 10. Furthermore, on the bottom surface of the resin substrate layer 10 with the glass substrate removed, a not-shown protective sheet is attached.
Through the above steps, the organic EL display device 50a of this embodiment can be manufactured. Note that this embodiment exemplifies the method of forming the reinforcing resin film 37b at the sealing film forming step, when the organic sealing film 37a is formed. Alternatively, the reinforcing resin film 37b may be formed at a mounting step following the sealing film forming step. The reinforcing resin film 37b may be formed of an organic resin material to be applied to an interior of the folding dam wall We using, for example, a dispenser apparatus.
As can be seen, as to the organic EL display device 50a and the method of manufacturing the organic EL display device 50a according to this embodiment, the folding dam wall We is provided around, and in contact with, the reinforcing resin film 37b on each of the routed wires 18j. When the reinforcing resin film 37b is formed by ink-jet printing at the sealing film forming step, such a feature can reduce excessive spreading of ink to form the reinforcing resin film 37b. This reduction in the excessive spreading of the ink reduces the width, of a portion of the frame region F along the folding portion B, in a direction perpendicular to the direction in which the folding portion B extends. Hence, the frame region of the organic EL display device 50a can be formed narrower even if the reinforcing resin film 37b is provided on the routed wires 18j in the folding portion B.
Moreover, as to the organic EL display device 50a and the method of manufacturing the organic EL display device 50a according to this embodiment, the folding dam wall We is provided to surround the reinforcing resin film 37b. Such a feature makes it possible to position a peripheral end portion of the reinforcing resin film 37b more precisely and control the thickness of the reinforcing resin film 37b more readily. As a result, the reinforcing resin film 37b can be formed highly flat. The flat reinforcing resin film 37b can reduce misalignment of the center of stress imposed when the organic EL display device 50a is folded at the folding portion B. Such a feature can keep a crack from opening on the routed wires 18j and the filling resin film 8, and reduce development of such a display defect as defective lines.
Furthermore, as to the organic EL display device 50a and the method of manufacturing the organic EL display device 50a according to this embodiment, the reinforcing resin film 37b is formed at the sealing film forming step. Such a feature can reduce contamination of the surface of the filling resin film 8 to be exposed from each of the routed wires 18j, compared with a case where the reinforcing resin film is formed at such a downstream process as, for example, the mounting step. Thanks to the reduction in contamination, the filling resin film 8 and the reinforcing resin film 37b adhere to each other more firmly. Such a feature can reduce delamination of the filling resin film 8 and the reinforcing resin film 37b from each other when the organic EL display device 50a is folded at the folding portion B. Here, at the sealing film forming step, the first inorganic sealing film 36 is formed by the plasma CVD, and the plasma treats the surface of the filling resin film 8 exposed from each of the routed wires 18j. Such a feature allows the filling resin film 8 and the reinforcing resin film 37b to adhere to each other more firmly.
In addition, as to the organic EL display device 50a and the method of manufacturing the organic EL display device 50a according to this embodiment, the reinforcing resin film 37b is formed at the sealing film forming step. Such a feature makes it possible to form the reinforcing resin film 37b on each of the routed wires 18j without an additional manufacturing step.
Moreover, as to the organic EL display device 50a and the method of manufacturing the organic EL display device 50a according to this embodiment, the reinforcing resin film 37b provided to the folding portion B is formed of the same material as that of the organic sealing film 37a, which is flexible and provided throughout the display region D. Such a feature can reduce stress to be imposed on the routed wires 18j when the organic EL display device 50a is folded at the folding portion B, making it possible to improve tolerance to cracks due to the fold.
The first embodiment exemplifies the organic EL display device 50a including the first electrodes 31a provided on the planarization resin film 19a. This embodiment exemplifies the organic EL display device 50b including a second planarization resin film 21a provided on a first planarization resin film 19a that is substantially the same in configuration as the planarization resin film 19a. On the second planarization resin film 21a, the first electrodes 31a are provided.
Similar to the organic EL display device 50a of the first embodiment, the organic EL display device 50b includes: the display region D; and the frame region F provided around the display region D.
Moreover, as illustrated in
As illustrated in
In the organic-EL-element layer 35 according to this embodiment, as illustrated in
Furthermore, similar to the organic EL display device 50a according to the first embodiment, the organic EL display device 50b illustrated in
The first frame dam wall Wa, as illustrated in
The second frame dam wall Wb, as illustrated in
Moreover, similar to the organic EL display device 50a of the first embodiment, the organic EL display device 50b includes the first frame wire 18h extending widely in a portion of the frame region F where the trench G is open. The first frame wire 18h has: opposing ends, toward the display region D, extending linearly behind the trench G along one side of the display region D; and opposing ends, across from the display region D, extending toward the terminal unit T. Note that, on the first frame wire 18h, a not-shown metal layer is stacked. The metal layer is formed of the same material as, and in the same layer as, the power source line 20a and the relay electrode 20b are. The metal layer can reduce wiring resistance of the first frame wire 18h.
Furthermore, similar to the organic EL display device 50a of the first embodiment, the organic EL display device 50b includes, in the frame region F, the second frame wire 18i shaped into a substantial C-shape and laid outside the trench G. The second frame wire 18i has opposing ends extending toward the terminal unit T. Here, on the second frame wire 18i, a metal layer 20c is stacked as illustrated in
In addition, similar to the organic EL display device 50a of the first embodiment, the organic EL display device 50b illustrated in
Moreover, as illustrated in
The filling resin film 19f is formed of the same material as, and in the same layer as, the first planarization resin film 19a is.
The plurality of routed wires 20j are provided to extend in parallel with one another in a direction perpendicular to the direction in which the folding portion B extends. The plurality of routed wires 20j are formed of the same material as, and in the same layer as, the power source line 20a and the relay electrode 20b are. Here, as illustrated in
As seen in the organic EL display device 50a of the first embodiment, the reinforcing resin film 37b in
Note that this embodiment exemplifies the organic EL display device 50b including the reinforcing resin film 37b provided on each of the routed wires 20j. Similar to Modification 1 of the organic EL display device 50a of the first embodiment, a base resin film may be formed of the same material as, and in the same layer as, the second planarization resin film 21a is, and the base resin film may be provided between the reinforcing resin film 37b and each of the routed wires 20j.
Moreover, this embodiment exemplifies the organic EL display device 50b including the folding dam wall We shaped into a frame and provided around the reinforcing resin film 37b. Similar to Modification 2 of the organic EL display device 50a of the first embodiment, a pair of the short side portions of the folding dam wall We may be removed.
Similar to the organic EL display device 50a of the above first embodiment, the organic EL display device 50b is flexible, and allows, in each of the sub-pixels P, the light-emitting layer 3 of the organic EL layer 33 to appropriately emit light through the first TFT 9a and the second TFT 9b to display an image.
The organic EL display device 50b of this embodiment can be manufactured as follows.
Specifically, the slit forming step is carried out in the TFT layer forming step of the method of manufacturing the organic EL display device 50a of the first embodiment. After that, a titanium film (a thickness of approximately 30 nm), an aluminum film (a thickness of approximately 300 nm), and a titanium film (a thickness of approximately 50 nm) are sequentially deposited by, for example, sputtering throughout the substrate in which the slit S is formed. After that, the multilayer film of these metals is patterned to form, for example, the source lines 18f, the first source conductive layer 18na, and the second source conductive layer 18nb.
Then, throughout the substrate on which, for example, the source lines 18f are formed, a polyimide-based photosensitive resin film (a thickness of approximately 2 μm) is applied by, for example, spin-coating or slit-coating. The applied film is prebaked, exposed to light, developed, and postbaked to form the first planarization resin film 19a in the display region D, to form the filling resin film 19f in the folding portion B of the frame region F, and to form, for example, the lower resin layer 19c in the frame region F other than the folding portion B (a filling resin film forming step).
After that, throughout the substrate on which the first planarization resin film 19a is formed, a titanium film (a thickness of approximately 30 nm), an aluminum film (a thickness of approximately 300 nm) and a titanium film (a thickness of approximately 50 nm) are sequentially deposited by, for example, sputtering. After that, the metal multilayer film of these metals is patterned to form the power source line 20a, the relay electrode 20b, and the routed wires 20j (a routed wire forming step).
Moreover, throughout the substrate on which, for example, the power source line 20a is formed, a polyimide-based photosensitive resin film (a thickness of approximately 2 μm) is applied by, for example, spin-coating or slit-coating. The applied film is prebaked, exposed to light, developed, and postbaked to form the second planarization resin film 21a. Here, when the second planarization film 21a is formed, the lower resin layer 21b to be included in the first frame dam wall Wa, the lower resin layer 21c to be included in the second frame dam wall Wb, and the lower resin layer 21d to be included in the folding dam wall We are also formed simultaneously (a first folding dam wall forming step).
Through the above steps, the TFT layer 30b of this embodiment can be formed. Subsequently, the organic-EL-element-layer forming step and the sealing film forming step of the method of manufacturing the organic EL display device 50a according to the first embodiment are sequentially carried out, and the organic EL display device 50b of this embodiment can be manufactured. Note that, also in this embodiment, as seen in the first embodiment, the reinforcing resin film 37b may be formed at the mounting step following the sealing film forming step. The reinforcing resin film 37b may be formed of an organic resin material to be applied to an interior of the folding dam wall We using, for example, a dispenser apparatus.
As can be seen, as to the organic EL display device 50b and the method of manufacturing the organic EL display device 50b according to this embodiment, the folding dam wall We is provided around, and in contact with, the reinforcing resin film 37b on each of the routed wires 20j. When the reinforcing resin film 37b is formed by ink-jet printing at the sealing film forming step, such a feature can reduce excessive spreading of ink to form the reinforcing resin film 37b. This reduction in the excessive spreading of the ink reduces the width, of a portion of the frame region F along the folding portion B, in a direction perpendicular to the direction in which the folding portion B extends. Hence, the frame region of the organic EL display device 50b can be formed narrower even if the reinforcing resin film 37b is provided on the routed wires 20j in the folding portion B.
Moreover, as to the organic EL display device 50b and the method of manufacturing the organic EL display device 50b according to this embodiment, the folding dam wall We is provided to surround the reinforcing resin film 37b. Such a feature makes it possible to position a peripheral end portion of the reinforcing resin film 37b more precisely and control the thickness of the reinforcing resin film 37b more readily. As a result, the reinforcing resin film 37b can be formed highly flat. The flat reinforcing resin film 37b can reduce misalignment of the center of stress imposed when the organic EL display device 50b is folded at the folding portion B. Such a feature can keep a crack from opening on the routed wires 20j and the filling resin film 19f, and reduce development of such a display defect as defective lines.
Furthermore, as to the organic EL display device 50b and the method of manufacturing the organic EL display device 50b according to this embodiment, the reinforcing resin film 37b is formed at the sealing film forming step. Such a feature can reduce contamination of the surface of the filling resin film 19f to be exposed from each of the routed wires 20j, compared with a case where the reinforcing resin film is formed at such a downstream process as, for example, the mounting step. Thanks to the reduction in contamination, the filling resin film 19f and the reinforcing resin film 37b adhere to each other more firmly. Such a feature can reduce delamination of the filling resin film 19f and the reinforcing resin film 37b from each other when the organic EL display device 50b is folded at the folding portion B. Here, at the sealing film forming step, the first inorganic sealing film 36 is formed by the plasma CVD, and the plasma treats the surface of the filling resin film 19f exposed from each of the routed wires 18j. Such a feature allows the filling resin film 19f and the reinforcing resin film 37b to adhere to each other more firmly.
In addition, as to the organic EL display device 50b and the method of manufacturing the organic EL display device 50b according to this embodiment, the reinforcing resin film 37b is formed at the sealing film forming step. Such a feature makes it possible to form the reinforcing resin film 37b on each of the routed wires 20j without an additional manufacturing step.
Moreover, as to the organic EL display device 50b and the method of manufacturing the organic EL display device 50b according to this embodiment, the reinforcing resin film 37b provided to the folding portion B is formed of the same material as that of the organic sealing film 37a, which is flexible and provided throughout the display region D. Such a feature can reduce stress to be imposed on the routed wires 20j when the organic EL display device 50a is folded at the folding portion B, making it possible to improve tolerance to cracks due to the fold.
Furthermore, as to the organic EL display device 50b and the method of manufacturing the organic EL display device 50b according to this embodiment, the filling resin film 19f provided to fill the slit S of the folding portion B is formed of the same material as, and in the same layer as, the first planarization resin film 19a. Such a feature allows effective use of the organic resin material included in the filling resin film 19f.
In the above embodiments, each organic EL layer is formed of a multilayer including such five layers as the hole-injection layer, the hole-transport layer, the light-emitting layer, the electron-transport layer, and the electron-injection layer. Alternatively, the organic EL layer may be formed of a multilayer including such three layers as a hole-injection and hole-transport layer, the light-emitting layer, and an electron-transport and electron-injection layer.
Moreover, in the organic EL display devices of the above embodiments described as examples, the first electrodes are anodes and the second electrode is a cathode. Alternatively, the present invention is applicable to an organic EL display device whose multilayered structure is inverted so that the first electrodes are cathodes and the second electrode is an anode.
Furthermore, in the organic EL display devices of the above embodiments described as examples, the electrodes of the TFTs connected to the first electrodes are drain electrodes. Alternatively, the present invention is applicable to an organic EL display device in which the electrodes of the TFTs connected to the first electrodes are referred to as source electrodes.
In addition, the display devices of the embodiments described as examples are organic EL display devices. Alternatively, the present invention is applicable to a display device including a plurality of light-emitting elements driven by a current. For example, the present invention is applicable to a display device including quantum-dot light emitting diodes (QLEDs); that is, light-emitting elements using layers containing quantum dots.
As can be seen, the present invention is applicable to a flexible display device.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/025080 | 6/25/2020 | WO |
