Display device including island-shaped inorganic films

A display device includes: a resin substrate; a TFT layer; a bending portion; at least one inorganic film forming the TFT layer; an interlayer insulating film forming the TFT layer; and a plurality of wires forming the TFT layer, wherein the at least one inorganic film and the interlayer insulating film include an opening disposed at the bending portion, the at least one inorganic film includes a plurality of island-shaped inorganic films remaining in the opening, each of the plurality of wires overlaps a corresponding island-shaped inorganic film among the plurality of island-shaped inorganic films, and the display device includes a metal layer in a form of islands disposed between each of the plurality of wires and the corresponding island-shaped inorganic film overlapping each of the plurality of wires, the metal layer being in contact with each of the plurality of wires.

TECHNICAL FIELD

The disclosure relates to a display device.

BACKGROUND ART

Attention has been recently drawn to self-emission organic EL display devices each using organic electroluminescence (EL) elements, as a display device instead of liquid-crystal displays. One of such organic EL display devices that has been proposed is a flexible organic EL display device in which the organic EL elements and other components are mounted on a flexible resin substrate. The organic EL display device herein has a rectangular display region for image display. Around the display region is a frame region, and this frame region needs to be scaled down. In the flexible organic EL display device, bending the frame region near a terminal to scale down the frame region, for instance, can break wires disposed in the frame region.

For instance, Patent Literature 1 discloses a flexible display device that has a bending hole, so that each of a buffer film, gate insulating film and interlayer insulating film corresponding to a bending region is partly removed to avoid a wire break.

CITATION LIST

Patent Literature

SUMMARY

Technical Problem

The flexible organic EL display device includes, on the resin substrate, inorganic insulating films, such as a base coat film, gate insulating film and interlayer insulating film. For the purpose of preventing a wire break in the frame region, the inorganic insulating films at a bending portion in the frame region can be removed to prevent the inorganic insulating films from a break at the bending portion. The wires in the frame region are, although disposed in a location where the inorganic insulating films at the bending portion have been removed, can be broken by excessive stress that is applied when the frame region is bent. The wires hence require improvements.

To solve the above problem, it is an object of the disclosure to prevent a wire break at the bending portion in the frame region.

Solution to Problem

To solve the above problem, the disclosure provides a display device that includes a resin substrate, a TFT layer disposed on the resin substrate, a light-emitting element disposed on the TFT layer and forming a display region, a frame region disposed around the display region, a terminal region disposed at the end of the frame region, a bending portion extending in one direction between the display region and the terminal region, at least one inorganic film forming the TFT layer and adjacent to the resin substrate, and an interlayer insulating film forming the TFT layer and more remote from the resin substrate than the at least one inorganic film is. The interlayer insulating film is made of an inorganic material. The display device also includes a plurality of wires forming the TFT layer. The wires are disposed on the interlayer insulating film in the frame region and extending in parallel with each other in a direction intersecting a direction where the bending portion extends. The at least one inorganic film and the interlayer insulating film have an opening disposed at the bending portion. The opening penetrates the at least one inorganic film and the interlayer insulating film in the thickness direction. The at least one inorganic film includes a plurality of island-shaped inorganic films remaining in the opening. Each of the wires overlaps a corresponding island-shaped inorganic film among the island-shaped inorganic films. The display device also includes a metal layer in the form of islands disposed between each of the wires and the island-shaped inorganic films overlapping each of the wires. The metal layer is in contact with each of the wires.

Advantageous Effect of Disclosure

In the disclosure, the island-shaped metal layer is disposed between each wire and the island-shaped inorganic film overlapping the wire and is in contact with the wire. This configuration can prevent a wire break at the bending portion in the frame region.

DESCRIPTION OF EMBODIMENTS

Embodiments of the disclosure will be detailed with reference to the drawings. The disclosure is not limited to the following embodiments.

First Embodiment

FIGS. 1 to 10each illustrate a first embodiment of a display device according to the disclosure. Each embodiment describes, by way of example only, an organic EL display device that includes organic EL elements, as a display device that includes light-emitting elements.FIG. 1is a schematic plan view of the configuration of an organic EL display device50aaccording to this embodiment.FIG. 2is a detailed plan view of the configuration of a display region D of the organic EL display device50a.FIG. 3is an equivalent circuit diagram of a TFT layer20forming the organic EL display device50a.FIG. 4is a detailed cross-sectional view of the configuration of the display region D of the organic EL display device50a, taken along line IV-IV inFIG. 1.FIG. 5is a cross-sectional view of an organic EL layer23forming the organic EL display device50a.FIG. 6is a plan view of a frame region F of the organic EL display device50a.FIG. 7is a cross-sectional view of the frame region F of the organic EL display device50a, taken along line VII-VII inFIG. 6. In the plan view ofFIG. 6, a flattening film19and an interlayer insulating film8(described later on) are omitted, and an arrangement of frame wires18hand gate conductive layers14dto14f(descried later on) is illustrated.

As illustrated inFIG. 1, the organic EL display device50ahas the rectangular display region D for image display, and the frame region F having a frame shape and disposed around the display region D.

Arranged in the display region D are multiple pixels in matrix. In each pixel, a sub-pixel P having a red-light-emitting region Lr for displaying red gradation, a sub-pixel P having a green-light-emitting region Lg for displaying green gradation, and a sub-pixel P having a blue-light-emitting region Lb for displaying blue gradation are arranged to be adjacent to each other as illustrated inFIG. 2for instance.

The frame region F has an end (i.e., the right end inFIG. 1) at which a terminal region T is disposed. The frame region F also has, between the display region D and the terminal region T, a bending portion B extending in one direction along one of the sides of the display region D (i.e., the right side in the drawing), as illustrated inFIG. 1. At the bending portion B, the frame region F is bent at 180 degrees (i.e., a U-shape) about an axis in the vertical direction of the drawing.

As illustrated inFIG. 4, the organic EL display device50aincludes, in the display region D, a resin substrate layer10, the TFT layer20disposed on the upper surface of the resin substrate layer10, organic EL elements30disposed on the TFT layer20, a front protective layer41disposed on the organic EL elements30, and a back protective layer42disposed on the lower surface of the resin substrate layer10.

The resin substrate layer10serves as a resin substrate and is made of, for instance, polyimide resin.

The TFT layer20includes the following components as illustrated inFIG. 4: a base coat film11adisposed on the resin substrate layer10; multiple first thin-film transistors (TFTs)9a, multiple second TFTs9band multiple capacitors9call of which are disposed on the base coat film11a; and a flattening film19disposed on the first TFTs9a, second TFTs9band capacitors9c. As illustrated inFIGS. 2 and 3, disposed in the TFT layer20are multiple gate lines14extending in parallel with each other in the horizontal direction of the drawings. As illustrated inFIGS. 2 and 3, also disposed in the TFT layer20are multiple source lines18fextending in parallel with each other in the vertical direction of the drawings. As illustrated inFIGS. 2 and 3, also disposed in the TFT layer20are multiple power-source lines18gthat extend in parallel with each other in the vertical direction of the drawings and are adjacent to the respective source lines18fIn the TFT layer20, each sub-pixel P has the corresponding first TFT9a, second TFT9band capacitor9cas illustrated inFIG. 3.

The base coat film11ais composed of an inorganic insulating monolayer film of, for instance, silicon nitride, silicon oxide or silicon oxide nitride, or is composed of an inorganic insulating laminated film of these materials.

The first TFT9ais connected to the corresponding gate line14and source line18fin each sub-pixel P, as illustrated inFIG. 3. As illustrated inFIG. 4, each first TFT9aincludes a semiconductor layer12ain the form of islands disposed on the base coat film11a, a gate insulating film13a(i.e., an inorganic film) disposed over the semiconductor layer12a, a gate electrode14adisposed on the gate insulating film13aand overlapping part of the semiconductor layer12a, an interlayer insulating film8disposed over the gate electrode14a, and a source electrode18aand drain electrode18bspaced away from each other on the interlayer insulating film8. The interlayer insulating film8herein includes a first interlayer insulating film15aadjacent to the gate electrode14a, and a second interlayer insulating film17astacked on the first interlayer insulating film15aand adjacent to the source electrode18aand drain electrode18b. The gate insulating film13a, first interlayer insulating film15a, and second interlayer insulating film17aare each composed of an inorganic insulating monolayer film of, for instance, silicon nitride, silicon oxide or silicon oxide nitride, or is composed of an inorganic insulating laminated film of these materials.

The second TFT9bin each sub-pixel P is connected to the corresponding first TFT9aand power-source line18g, as illustrated inFIG. 3. The second TFT9bincludes, as illustrated inFIG. 4, a semiconductor layer12bin the form of islands disposed on the base coat film11a, a gate insulating film13a(i.e., an inorganic film) disposed over the semiconductor layer12b, a gate electrode14bdisposed on the gate insulating film13aand overlapping part of the semiconductor layer12b, the interlayer insulating film8disposed over the gate electrode14b, and a source electrode18cand drain electrode18dspaced away from each other on the interlayer insulating film8. Although the first TFTs9aand the second TFTs9bare each a top-gate TFT in this embodiment by way of example only, these TFTs each may be a bottom-gate TFT.

The capacitor9cin each sub-pixel P is connected to the corresponding first TFT9aand power-source line18g, as illustrated inFIG. 3. The capacitor9cincludes, as illustrated inFIG. 4, a lower conductive layer14cdisposed in the same layer as the gate electrodes and made of the same material as the gate electrodes, includes the first interlayer insulating film15adisposed over the lower conductive layer14c, and includes an upper conductive layer16a(i.e., a capacitance line) disposed on the first interlayer insulating film15aand overlapping the lower conductive layer14c. As illustrated inFIG. 4, the upper conductive layer16ais between the first interlayer insulating film15aand the second interlayer insulating film17a, and is connected to the power-source line18gthrough a contact hole disposed in the second interlayer insulating film17.

The flattening film19is made of colorless transparent organic resin material, such as polyimide resin.

The organic EL elements30are light-emitting elements constituting the display region D. The organic EL elements30include, as illustrated inFIG. 4, multiple first electrodes21, an edge cover22, multiple organic EL layers23, a second electrode24, and a seal film29.

The first electrodes21are arranged in matrix on the flattening film19so as to correspond to the sub-pixels P, as illustrated inFIG. 4. As illustrated inFIG. 4, each first electrode21is connected to the drain electrode18dof the corresponding second TFT9bthrough a contact hole disposed in the flattening film19. The first electrodes21have the function of injecting holes into the organic EL layers23. The first electrodes21are preferably made of material having a large work function, in order to improve the efficiency of hole injection into the organic EL layers23. The first electrode21is made of metal material, including 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). The first electrodes21may be made of an alloy of, for instance, astatine (At) and astatine oxide (AtO2). Furthermore, the first electrodes21may be made of conductive oxide, such as tin oxide (SnO), zinc oxide (ZnO), indium tin oxide (ITO), or indium zinc oxide (IZO). The first electrodes21each may be composed of a stack of multiple layers made of the above materials. Here, examples of a compound material having a large work function include indium tin oxide (ITO) and indium zinc oxide (IZO).

The edge cover22is disposed in lattice and covers the perimeter of each first electrode21, as illustrated inFIG. 4. The edge cover22is an organic film made of, for instance, polyimide resin, acrylic resin, polysiloxane resin, or novolak resin.

The organic EL layers23are disposed on the respective first electrodes21and are arranged in matrix so as to correspond to the sub-pixels, as illustrated inFIG. 4. As illustrated inFIG. 5, each organic EL layer23includes, sequentially on the first electrode21, a hole injection layer1, a hole transport layer2, a light-emitting layer3, an electron transport layer4, and an electron injection layer5.

The hole injection layer1is also called an anode buffer layer and has the function of bringing the energy levels of the first electrode21and organic EL layer23close to each other to improve the efficiency of hole injection from the first electrode21to the organic EL layer23. Examples of the material of the hole injection layer1include a triazole derivative, oxadiazole derivative, imidazole derivative, polyarylalkane derivative, pyrazoline derivative, phenylenediamine derivative, oxazole derivative, styrylanthracene derivative, fluorenone derivative, hydrazone derivative, and stilbene derivative.

The electron injection layer5has the function of bringing the energy levels of the second electrode24and organic EL layer23close to each other to improve the efficiency of electron injection from the second electrode24to the organic EL layer23. This function can lower voltage for driving the organic EL elements30. The electron injection layer5is also called a cathode buffer layer. Examples of the material of the electron injection layer5include an inorganic alkali compound, such as lithium fluoride (LiF), magnesium fluoride (MgF2), calcium fluoride (CaF2), strontium fluoride (SrF2), and barium fluoride (BaF2), and include aluminum oxide (Al2O3) and strontium oxide (SrO).

The second electrode24is disposed over the organic EL layers23and edge cover22, as illustrated inFIG. 4. The second electrode24has the function of injecting the holes into the organic EL layers23. The second electrode24is preferably made of material having a small work function, in order to improve the efficiency of hole injection into the organic EL layers23. The second electrode24is a vapor-deposited film formed through vacuum deposition. Examples of the material of the second electrode24include silver (Ag), aluminum (Al), vanadium (V), calcium (Ca), titanium (Ti), yttrium (Y), sodium (Na), manganese (Mn), indium (In), magnesium (Mg), lithium (Li), ytterbium (Yb), and lithium fluoride (Lif). The second electrode24may be made of, for instance, an alloy of magnesium (Mg) and copper (Cu), an alloy of magnesium (Mg) and silver (Ag), an alloy of sodium (Na) and potassium (K), an alloy of astatine (At) and astatine oxide (AtO2), an alloy of lithium (Li) and aluminum (Al), an alloy of lithium (Li), calcium (Ca) and aluminum (Al), or an alloy of lithium fluoride (LiF), calcium (Ca) and aluminum (Al). The second electrode24may be alternatively made of conductive oxide, such as tin oxide (SnO), zine oxide (ZnO), indium tin oxide (ITO), or indium zinc oxide (IZO). The second electrode24may be composed of multiple stacked layers made of the above materials. Examples of the material 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).

As illustrated inFIG. 4, the seal film29is disposed over the second electrode24and includes, sequentially on the second electrode24, a first inorganic seal film26, an organic seal film27, and a second inorganic seal film28. The seal film29has the function of protecting the organic EL layer23from moisture and oxygen.

The first inorganic seal film26and the second inorganic seal film28are each composed of an inorganic insulating film, such as a silicon nitride film, silicon oxide film, or silicon oxide nitride film.

The organic seal film27is made of organic resin material, such as acrylate, epoxy, silicone, polyuria, parylene, polyimide, or polyamide.

The front protective layer and41and the back protective layer42are made of polyimide resin that is about 2 μm thick, for instance.

As illustrated inFIGS. 6 and 7, the organic EL display device50aincludes the following components in the frame region F: the resin substrate layer10; the base coat film11a, gate insulating film13aand interlayer insulating film8sequentially disposed on the upper surface of the resin substrate layer10; the multiple frame wires18hdisposed on the interlayer insulating film8and extending in parallel with each other in a direction orthogonal to a direction where the bending portion B extends; and the flattening film19disposed over the frame wires18h. The front protective layer41and the back protective layer42, which are disposed in the display region D, are disposed in most part of the frame region F as well except the bending portion B.

As illustrated inFIG. 7, the base coat film11a, gate insulating film13aand interlayer insulating film8have, at the bending portion B in the frame region F, an opening A penetrating the base coat film11a, gate insulating film13a, and interlayer insulating film8in the thickness direction to expose the upper surface of the resin substrate layer10. The opening A herein is a groove penetrating in the direction where the bending portion B extends, as illustrated inFIG. 7.

The base coat film11aand the gate insulating film13aremain in the form of islands in the opening A, and constitute multiple base coat layers11aaand multiple gate insulating layers13aa. In plan view, the base coat layers11aaand the gate insulating layers13aaeach have a size of about 10 μm×10 μm and have a density of about 1250 islands/mm2, for instance.

As illustrated inFIG. 7, each frame wire18hoverlaps, in the opening A, the corresponding base coat layers11aaand corresponding gate insulating layers13aaamong the multiple base coat layers11aaand multiple gate insulating layers13aa. As illustrated inFIGS. 6 and 7, disposed between the frame wire18hand the gate insulating layers13aaoverlapping the frame wire18his the third gate conductive layer14f(i.e., a metal layer M) in the form of islands that are in contact with the frame wire18h. As illustrated inFIG. 7, both ends of the frame wire18hare connected to the respective first gate conductive layer14dand second gate conductive layer14evia a respective first contact hole Ca and second contact hole Cb disposed in the interlayer insulating film8. As illustrated inFIG. 7, the frame wire18his in contact with the upper surface of the resin substrate layer10, in at least part of the opening A of the base coat film11a, gate insulating film13aand interlayer insulating film8. The frame wire18his disposed in the same layer as the source electrode18aand other components, and is made of the same material as the source electrode18aand other components.

The first gate conductive layer14dis disposed between the gate insulating film13aand the first interlayer insulating film15a, as illustrated inFIG. 7. The gate conductive layer14dis electrically connected to signal wires (e.g., the gate lines14, source lines18f, and power-source lines18g) disposed in the TFT layer20in the display region D. The first gate conductive layer14d, the second gate conductive layer14e, and the third gate conductive layer14fare disposed in the same layer as the gate electrode14aand other components, and are made of the same material as the gate electrode14aand other components.

The second gate conductive layer14eis disposed between the gate insulating film13aand the first interlayer insulating film15a, as illustrated inFIG. 7. The second gate conductive layer14eextends to the terminal region T.

As illustrated inFIG. 7, the third gate conductive layer14fis provided in such a manner that its perimeter surface at the lower part of the drawing coincides with the perimeter surface of the gate insulating layer13aa. Here, the coincidence between these perimeter surfaces means that the perimeter surfaces coincide with each other in order to simultaneously undergo etching with the same photo mask and then undergo patterning. This coincidence includes a gap between the perimeter surfaces resulting from a slight difference in etching rate in the vertical direction. Reference is made to a pair of the frame wires18hadjacent to each other. As illustrated inFIG. 6, the third gate conductive layer14falong one of the frame wires18hand the third gate conductive layer14falong the other frame wire18hare arranged in a staggered manner so as to overlap each other at their ends in a direction where the frame wires18hextend (i.e., the lateral direction in the drawing), and so as not to overlap each other in a direction orthogonal to the direction where the frame wires18hextend (i.e., the vertical direction in the drawing).

This embodiment has described, by way of example only, the organic EL display device50athat has the opening A penetrating the base coat film11a, gate insulating film13aand interlayer insulating film8. Another embodiment may provide an organic EL display device50bthat has the opening A penetrating the gate insulating film13aand interlayer insulating film8, as illustrated inFIG. 8.FIG. 8is a cross-sectional view of the frame region F of the organic EL display device50b, which is a first modification of the organic EL display device50a.FIG. 8corresponds toFIG. 7.

To be specific, the organic EL display device50bhas no through-holes in the base coat film11b, and has a recess disposed in the upper surface of the base coat film11band overlapping the opening A of the gate insulating film13aand interlayer insulating film8, as illustrated inFIG. 8. Here, the frame wire18hinFIG. 8is in contact with the upper surface of the base coat film11b(or the bottom and side surfaces of the recess of this upper surface), in at least part of the opening A of the gate insulating film13aand interlayer insulating film8.

The present embodiment has described, by way of example only, the organic EL display device50a, whose opening A disposed in the base coat film11a, gate insulating film13aand interlayer insulating film8has a flush end surface. In some embodiments, an organic EL display device50cmay be used whose openings Aa and Ab disposed in the gate insulating film13a, the interlayer insulating film8and a base coat film11chave end surfaces forming a step.FIG. 9is a cross-sectional view of the frame region F of the organic EL display device50c, which is a second modification of the organic EL display device50a.FIG. 9corresponds toFIG. 7.

To be specific, the organic EL display device50cis configured such that the end surface of the opening Ab, disposed in the base coat film11b, protrudes inward from the opening Aa, disposed in the gate insulating film13and interlayer insulating film8, to form a step. As illustrated inFIG. 9, the frame wire18his in contact with the upper surface of the resin substrate layer10, in at least part of the opening Ab of the base coat film11b.

This embodiment has described, by way of example only, a stack of the base coat film11aand gate insulating film13aas an inorganic film having the opening A. In some embodiments, the inorganic film having the opening A may be composed of at least one of the base coat film11a, a semiconductor film (i.e., the semiconductor layers12aand12b) and the gate insulating film13a.

In each sub-pixel P, inputting a gate signal to the first TFT9athrough the gate line14to turn on the first TFT9a, followed by applying a predetermined voltage corresponding to a source signal to the gate electrode of the second TFT9band to the capacitor9cthrough the source line18f, to supply a current defined based on a gate voltage across the second TFT9band coming from the power-source line18gcauses the light-emitting layer3of the organic EL layer23to emit light. This enables the organic EL display device50ato display an image. In the organic EL display device50a, the gate voltage across the second TFT9bis maintained by the capacitor9ceven when the first TFT9ais turned off; thus, the light-emitting layer3keeps light emission until a gate signal in the next frame is input.

A method for manufacturing the organic EL display device50aaccording to this embodiment will be described with reference toFIG. 10.FIG. 10illustrates, in cross-section, process steps for manufacturing the organic EL display device50a.FIG. 10(a)is a cross-sectional view of the organic EL display device50abefore first etching,FIG. 10(b)is a cross-sectional view of the same after the first etching,FIG. 10(c)is a cross-sectional view of the same after second etching, andFIG. 10(d)is a cross-sectional view of the same after wire formation. The method for manufacturing the organic EL display device50aaccording to this embodiment includes the following process steps: TFT-layer formation including the first etching, second etching and wire formation; organic-EL-element formation; and processing for flexibility.

Forming of TFT Layer

The TFT layer20is formed by forming, through a well-known method, the base coat film11a, first TFT9a, second TFT9b, capacitor9cand flattening film19onto the front surface of the resin substrate layer10disposed on a glass substrate, for instance.

The following details how the base coat film11a, the opening A of the gate insulating film13aand interlayer insulating film8, and the frame wire18hare formed at the bending portion B in the frame region F when the first TFT9a, second TFT9band capacitor9care formed in the display region D.

As illustrated inFIG. 10(a), the substrate before the source line18fand other components are formed has a stack of, in this order, a first inorganic insulating film11(that is to be the base coat film11a), second inorganic insulating film13(that is to be the gate insulating film13a), third inorganic insulating film15(that is to be the first interlayer insulating film15a), and fourth inorganic insulating film17(that is to be the second interlayer insulating film17a).

As illustrated inFIG. 10(c), showing the second etching step, the opening Ab is then formed in the first inorganic insulating film11exposed from the stack of the gate insulating film13a, first interlayer insulating film15aand second interlayer insulating film17a, through dry etching.

Furthermore, a metal conductive film is formed onto all over the substrate that has now the opening Ab in the first inorganic insulating film11, through sputtering. The metal conductive film then undergoes photolithography, etching and resist peeling to form the frame wire18has illustrated inFIG. 10(d), showing the wire formation step. The source electrodes18aand18c, the drain electrodes18band18d, the source line18f, and the power-source line18gare also formed simultaneously in the step of forming the frame wire18h.

Forming of Organic EL Element

First, the first electrode21, the edge cover22, the organic EL layer23(i.e., the hole injection layer1, the hole transport layer2, the light-emitting layer3, the electron transport layer4, and the electron injection layer5), and the second electrode24are formed onto the TFT layer20, which is formed in the step of forming the TFT layer, through a well-known method.

Then, the organic EL element30is formed through the following process steps: forming the first inorganic seal film26composed of an inorganic insulating film (e.g., a silicon nitride film) formed through, for instance, plasma chemical vapor deposition (CVD) so as to cover the second electrode24, followed by forming the organic seal film27onto the first inorganic seal film26through ink jetting, followed by forming the seal film29by forming, onto the organic seal film27, the second inorganic seal film28composed of an inorganic insulating film (e.g., a silicon nitride film) formed through plasma CVD.

Processing for Flexibility

The front protective layer41is attached onto the front surface of the seal film29of the organic EL element30, formed in the step of forming the organic EL element, followed by laser light irradiation from a surface of the resin substrate layer10adjacent to the glass substrate to peel the glass substrate off from the lower surface of the resin substrate layer10, followed by attaching the back protective layer42onto the lower surface of the resin substrate layer10with the glass substrate peeled off therefrom.

The organic EL display device50aaccording to this embodiment can be manufactured through these process steps.

As described above, the organic EL display device50aaccording to this embodiment is configured such that the base coat film11a, gate insulating film13aand interlayer insulating film8have, at the bending portion B in the frame region F, the opening A penetrating the base coat film11a, gate insulating film13a, and interlayer insulating film8in the thickness direction. Herein, the base coat film11aand the gate insulating film13aremain in the form of multiple islands in the opening A, and constitute the base coat layers11aaand the gate insulating layers13aa. Moreover, each frame wire18hon the interlayer insulating film8overlaps the corresponding island-shaped base coat layers11aaand corresponding island-shaped gate insulating layers13as in the opening A. In addition, the third gate conductive layer14fis disposed in the form of islands between each frame wire18hand the gate insulating layers13aaoverlapping each frame wire18h. The third gate conductive layer14fis in contact with each frame wire18h. Consequently, even if the frame wire18hbreaks at a site overlapping the third gate conductive layer14f, the third gate conductive layer14foverlapping this site can establish continuity in the frame wire18hand improve the redundancy of the frame wire18h, thereby preventing the frame wire18hfrom a break at the bending portion B in the frame region F.

The organic EL display device50aaccording to this embodiment is configured such that in a pair of the frame wires18hadjacent to each other, the third gate conductive layer14falong one of the frame wires18and the third gate conductive layer14falong the other frame wire18hoverlap in a direction where the frame wires18hextend, and do not overlap in a direction orthogonal to the direction where the frame wires18hextend. When the third gate conductive layers14fare disposed in each frame wire18h, this configuration can bring the adjacent frame wires18hclose to each other, thereby reducing the distance between the adjacent frame wires18h.

Second Embodiment

FIG. 11illustrates a second embodiment of the display device according to the disclosure.FIG. 11is a cross-sectional view of the frame region F of an organic EL display device50daccording to this embodiment.FIG. 11corresponds toFIG. 7. In the subsequent embodiments, components that are the same as those shown inFIGS. 1 to 10will be denoted by the same signs and will not be elaborated upon.

The first embodiment has described, by way of example only, that the organic EL display devices50ato50ceach include the third gate conductive layers14f(i.e., metal layers M) that are in contact with the frame wires18h. The second embodiment describes, by way of example only, that the organic EL display device50dincludes capacitive conductive layers16b(i.e., metal layers M) that are in contact with frame wires18i.

The organic EL display device50dhas the rectangular display region D and the frame region F having a frame shape and disposed around the display region D, like the organic EL display device50aaccording to the first embodiment.

Like the organic EL display device50aaccording to the first embodiment, the organic EL display device50dincludes, in the display region D, the resin substrate layer10, the TFT layer20disposed on the upper surface of the resin substrate layer10, the organic EL elements30disposed on the TFT layer20, the front protective layer41disposed on the organic EL elements30, and the back protective layer42disposed on the lower surface of the resin substrate layer10.

The organic EL display device50dalso includes the following components in the frame region F: the resin substrate layer10; the base coat film11a, gate insulating film13aand interlayer insulating film8sequentially disposed on the upper surface of the resin substrate layer10; the multiple frame wires18idisposed on the interlayer insulating film8and extending in parallel with each other in a direction orthogonal to a direction where the bending portion B extends; and the flattening film19disposed over the frame wires18i.

As illustrated inFIG. 11, each frame wire18ioverlaps, in the opening A, the corresponding base coat layers11aaand corresponding gate insulating layers13aaamong the multiple base coat layers11aaand multiple gate insulating layers13aa. Disposed between the frame wire18iand the gate insulating layers13aa, overlapping the frame wire18i, is the capacitive conductive layer16b(i.e., a metal layer M) in the form of islands that are in contact with the frame wire18i, as illustrated inFIG. 11. As illustrated inFIG. 11, both ends of the frame wire18iare connected to the respective first gate conductive layer14dand second gate conductive layer14evia the respective first contact hole Ca and second contact hole Cb that are disposed in the interlayer insulating film8. As illustrated inFIG. 11, the frame wire18his in contact with the upper surface of the resin substrate layer10, in at least part of the opening A of the base coat film11a, gate insulating film13aand interlayer insulating film8. The frame wire18iis disposed in the same layer as the source electrode18aand other components, and is made of the same material as the source electrode18aand other components. Moreover, the capacitive conductive layer16bis disposed in the same layer as the upper conductive layer16aand is made of the same material as the upper conductive layer16a.

Like the organic EL display device50aaccording to the first embodiment, the organic EL display device50dis flexible, and displays an image when the light-emitting layer3of the organic EL layer23in each sub-pixel P is caused to emit light, as appropriate, via the first TFT9aand second TFT9b.

The organic EL display device50daccording to the second embodiment can be manufactured by generally using the method for manufacturing the organic EL display device50aaccording to the first embodiment, with the exception that the pattern shape of the metal conductive film for forming the gate electrode14aand the pattern shape of the metal conductive film for forming the upper conductive layer16aneed to be changed.

As described above, the organic EL display device50daccording to this embodiment is configured such that the base coat film11a, gate insulating film13aand interlayer insulating film8at the bending portion B in the frame region F has the opening A penetrating the base coat film11a, gate insulating film13a, and interlayer insulating film8in the thickness direction. Herein, the base coat film11aand the gate insulating film13aremain in the form of multiple islands in the opening A, and constitute the base coat layers11aaand the gate insulating layers13aa. Moreover, each frame wire18ion the interlayer insulating film8overlaps the corresponding island-shaped base coat layers11aaand corresponding island-shaped gate insulating layers13aain the opening A. In addition, the capacitive conductive layer16bis disposed in the form of islands between each frame wire18iand the gate insulating layers13aaoverlapping each frame wire18i. The capacitive conductive layer16bis in contact with each frame wire18i. Consequently, even if the frame wire18ibreaks at a site overlapping the capacitive conductive layer16b, the capacitive conductive layer16boverlapping this site can establish continuity in the frame wire18iand improve the redundancy of the frame wire18i, thereby preventing the frame wire18ifrom a break at the bending portion B in the frame region F.

Third Embodiment

FIG. 12illustrates a third embodiment of the display device according to the disclosure.FIG. 12is a cross-sectional view of the frame region F of an organic EL display device50eaccording to this embodiment.FIG. 12corresponds toFIG. 7.

The first and second embodiments have described, by way of example only, that the organic EL display devices50ato50deach include either gate conductive layers or capacitive conductive layers as the metal layers M that are in contact with the frame wires18hor18i. The third embodiment describes, by way of example only, that the organic EL display device50eincludes a stack of gate conductive layers and capacitive conductive layers as the metal layers M that are in contact with frame wires18j.

Like the organic EL display device50aaccording to the first embodiment, the organic EL display device50ehas the rectangular display region D and the frame region F having a frame shape and disposed around the display region D.

Like the organic EL display device50aaccording to the first embodiment, the organic EL display device50eincludes, in the display region D, the resin substrate layer10, the TFT layer20disposed on the upper surface of the resin substrate layer10, the organic EL elements30disposed on the TFT layer20, the front protective layer41disposed on the organic EL elements30, and the back protective layer42disposed on the lower surface of the resin substrate layer10.

The organic EL display device50ealso includes the following components in the frame region F as illustrated inFIG. 12: the resin substrate layer10; the base coat film11a, gate insulating film13a, and interlayer insulating film8sequentially disposed on the upper surface of the resin substrate layer10; the multiple frame wires18jdisposed on the interlayer insulating film8and extending in parallel with each other in a direction orthogonal to a direction where the bending portion B extends; and the flattening film19disposed over the frame wires18j.

As illustrated inFIG. 12, each frame wire18joverlaps, in the opening A, the corresponding base coat layers11aaand corresponding gate insulating layers13aaamong the multiple base coat layers11aaand multiple gate insulating layers13aa. As illustrated inFIG. 12, disposed between each frame wire18jand the gate insulating layers13aaoverlapping the frame wire18jis the metal layer M in the form of islands that are in contact with the frame wire18j. Each metal layer M includes the third gate conductive layer14fand a capacitive conductive layer16cstacked on the third gate conductive layer14fAs illustrated inFIG. 12, both ends of the frame wire18jare connected to the respective first gate conductive layer14dand second gate conductive layer14evia the respective first contact hole Ca and second contact hole Cb that are disposed in the interlayer insulating film8. As illustrated inFIG. 12, the frame wire18jis in contact with the upper surface of the resin substrate layer10, in at least part of the opening A of the base coat film11a, gate insulating film13aand interlayer insulating film8. The frame wire18jis disposed in the same layer as the source electrode18aand other components, and is made of the same material as the source electrode18aand other components. Moreover, the capacitive conductive layer16cis disposed in the same layer as the upper conductive layer16aand is made of the same material as the upper conductive layer16a.

Like the organic EL display device50aaccording to the first embodiment, the organic EL display device50eis flexible, and displays an image when the light-emitting layer3of the organic EL layer23in each sub-pixel P is caused to emit light, as appropriate, via the first TFT9aand second TFT9b.

The organic EL display device50eaccording to the third embodiment can be manufactured by generally using the method for manufacturing the organic EL display device50aaccording to the first embodiment, with the exception that the pattern shape of the metal conductive film for forming the gate electrode14aand the pattern shape of the metal conductive film for forming the upper conductive layer16aneed to be changed.

As described above, the organic EL display device50eaccording to this embodiment is configured such that the base coat film11a, gate insulating film13aand interlayer insulating film8at the bending portion B in the frame region F has the opening A penetrating the base coat film11a, gate insulating film13a, and interlayer insulating film8in the thickness direction. Herein, the base coat film11aand the gate insulating film13aremain in the form of multiple islands in the opening A, and constitute the base coat layers11aaand the gate insulating layers13aa. Moreover, each frame wire18jon the interlayer insulating film8overlaps the corresponding island-shaped base coat layers11aaand corresponding island-shaped gate insulating layers13aain the opening A. In addition, disposed between each frame wire18jand the gate insulating layers13aaoverlapping the frame wire18jis the metal layer M in the form of islands that are in contact with the frame wire18j. Each metal layer M includes the third gate conductive layer14fand the capacitive conductive layer16c. Consequently, even if the frame wire18jbreaks at a site overlapping the metal layer M, the metal layer M overlapping this site can establish continuity in the frame wire18jand improve the redundancy of the frame wire18j, thereby preventing the frame wire18jfrom a break at the bending portion B in the frame region F.

Other Embodiments

The foregoing embodiments have described, by way of example only, an organic EL layer having a five-ply stack of a hole injection layer, hole transport layer, light-emitting layer, electron transport layer and electron injection layer. In some embodiments, an organic EL layer may be provided that has a three-ply stack of a hole injection-and-transport layer, light-emitting layer and electron transport-and-injection layer.

The foregoing embodiments have described, by way of example only, an organic EL display device that has a first electrode as an anode electrode and a second electrode as a cathode electrode. The disclosure is also applicable to an organic EL display device in which the organic EL layer has an inverted stack of layers: the first electrode as a cathode electrode and the second electrode as an anode electrode.

The foregoing embodiments have described, by way of example only, an organic EL display device that includes an element substrate with electrodes of TFTs connected to the first electrode, serving as drain electrodes. The disclosure is also applicable to an organic EL display device that includes an element substrate with the electrodes of the TFTs connected to the first electrode, serving as source electrodes.

The foregoing embodiments have described an organic EL display device as a display device by way of example only. The disclosure is applicable to a display device that includes multiple light-emitting elements driven by current. For instance, the disclosure is applicable to a display device that includes quantum-dot light-emitting diodes (QLEDs), which are light-emitting elements using a quantum-dot-containing layer.

INDUSTRIAL APPLICABILITY

As described above, the disclosure is useful for a flexible display device.