Display device

Abstract

The invention provides a display device. The display device includes: a substrate including a display region having a plurality of pixels and an end region having a connection portion; a flexible wiring substrate including wiring and a flexible base material; a driving IC chip provided on the flexible wiring substrate; and a protective member which extends from an end portion of the substrate, and which is bent in a bending region in which the flexible wiring substrate overlaps with the wiring of the flexible wiring substrate, the driving IC chip faces the display region, and the elastic modulus of the protective member is 10 MPa to 20 MPa (inclusive).

Description

[0001] This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2023-149094 filed on September 14, 2023, the entire contents of which are incorporated herein. Technical Field

[0002] Embodiments of the present invention relate to a display device. Background Art

[0003] A flat panel display such as an organic electroluminescence (EL) display device has a display panel in which thin film transistors (TFT) or organic light-emitting diodes (OLED) are formed on a substrate. Summary of the invention

[0004] An object of this embodiment is to provide a display device capable of achieving a narrow frame.

[0005] A display device according to one embodiment includes:

[0006] A substrate including a display region having a plurality of pixels and an end region having a connection portion;

[0007] A flexible wiring substrate including wiring and a flexible base material;

[0008] a driver IC chip disposed on the flexible wiring substrate; and

[0009] a protective member extending from an end portion of the substrate and overlapping the wiring of the flexible wiring substrate,

[0010] the flexible wiring substrate is bent in the bending region,

[0011] The driver IC chip is opposite to the display area,

[0012] The elastic modulus of the protection member is 10 MPa to 20 MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a perspective view showing a configuration example of a display device according to an embodiment.

[0014] Figure 2 Observed from the back side Figure 1 A diagram showing a display device.

[0015] Figure 3 It is a cross-sectional view showing an example of a schematic configuration of a display device according to a comparative example.

[0016] Figure 4 It is a cross-sectional view showing an example of a schematic configuration of a display device according to a comparative example.

[0017] Figure 5 This is a cross-sectional view showing an example of a schematic configuration of a display device according to an embodiment.

[0018] Figure 6 This is a cross-sectional view showing an example of a schematic configuration of a display device according to an embodiment.

[0019] Figure 7 This is a diagram showing the relationship between the elastic modulus of the protection member and the distance that the flexible wiring board protrudes outward from the end of the board.

[0020] Figure 8 It is a partial plan view showing an example of a schematic configuration of a display panel.

[0021] Fig. 9 It is along Figure 8 A cross-sectional view of the display panel taken along line A1 - A2 is shown. DETAILED DESCRIPTION

[0022] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the present disclosure is only an example, and appropriate changes that maintain the gist of the invention and are easily conceivable by those skilled in the art are of course included in the scope of the present invention. In addition, in order to make the description more accurate, the width, thickness, shape, etc. of each part of the accompanying drawings are sometimes schematically shown compared to the actual form, but this is only an example and does not limit the interpretation of the present invention. In addition, in this specification and each figure, the same figure mark is sometimes marked on the same element as the element in the accompanying drawing description that has already appeared, and the detailed description is appropriately omitted.

[0023] The embodiments described in this specification are not general embodiments, but are embodiments that illustrate the same or corresponding special technical features of the present invention. Figure 1 A display device according to one embodiment will be described in detail.

[0024] In the present embodiment, the first direction X, the second direction Y, and the third direction Z are orthogonal to each other, but may intersect at an angle other than 90 degrees. The direction in which the arrow of the third direction Z points to the front end is defined as up or above, and the direction on the opposite side of the direction in which the arrow of the third direction Z points to the front end is defined as down or below. In addition, there are also cases where the first direction X, the second direction Y, and the third direction Z are respectively referred to as the X direction, the Y direction, and the Z direction.

[0025] In addition, in the case of "the second member above the first member" and "the second member below the first member", the second member may be in contact with the first member or may be separated from the first member. In the latter case, a third member may be provided between the first member and the second member. On the other hand, in the case of "the second member above the first member" and "the second member below the first member", the second member is in contact with the first member.

[0026] In addition, it is assumed that there is an observation position for observing the display device on the front end side of the arrow in the third direction Z, and observation from the observation position toward the XY plane defined by the first direction X and the second direction Y is referred to as a top view. Observation of a cross section of the display device in the XZ plane defined by the first direction X and the third direction Z, or in the YZ plane defined by the second direction Y and the third direction Z is referred to as a cross-sectional view.

[0027] [Implementation Method]

[0028] Figure 1 It is a perspective view showing a configuration example of the display device according to the present embodiment. Figure 1 The display device DSP shown includes, for example, an active matrix display panel PNL.

[0029] The display device DSP includes a display area DA and a peripheral area FA provided around the display area DA on the substrate SUB1. The display device DSP includes a plurality of pixels PX arranged in the display area DA. In the display device DSP, light LT from the pixels PX is emitted upward.

[0030] The surface from which the light LT of the display panel PNL is emitted is referred to as surface FF. The surface opposite to the surface FF in the third direction Z is referred to as surface RF. The surface FF can be referred to as an emission surface, a front surface, or an upper surface, and the surface RF can be referred to as a rear surface or a lower surface.

[0031] The area EA at the end of the substrate SUB1 is arranged outside the display area DA. The area EA is also referred to as the end area of ​​the display panel PNL. A connection portion WPD is provided in the area EA. A wiring from the display area DA extends from the connection portion WPD. The wiring from the display area DA is a scan line or a signal line from a pixel PX, or a wiring connected to a scan line or a signal line.

[0032] A flexible wiring board FPC1 is provided at the connection portion WPD in the area EA. The flexible wiring board FPC1 has a plurality of wirings arranged along the first direction X. The wirings of the flexible wiring board FPC1 are electrically connected to the connection portion WPD via an anisotropic conductive film (ACF). Thus, the wirings from the display area DA and the wirings of the flexible wiring board FPC1 are electrically connected.

[0033] As for the end of the flexible wiring substrate FPC1, the end close to the connection portion WPD is referred to as the end EF11. The end on the opposite side of the end EF11 along the second direction Y is referred to as the end EF12. The surface of the flexible wiring substrate FPC1 on the same side as the surface FF is referred to as the surface FP. The surface of the flexible wiring substrate FPC1 on the same side as the surface RF is referred to as the surface RP.

[0034] The flexible wiring substrate FPC1 is mounted with a driver IC chip ICP as a signal supply source for supplying signals required to drive the display panel PNL. That is, the flexible wiring substrate FPC1 is a COF (Chip On Film). The end EF12 of the flexible wiring substrate FPC1 extends from the end ES11 of the substrate SUB1. The driver IC chip ICP is provided in the extended area.

[0035] Figure 2 Observed from the back side Figure 1 FIG. 1 shows a display device. Figure 2 As shown, the flexible wiring board FPC1 of the display device DSP is folded back to the back surface RF side of the display panel PNL. The area where the flexible wiring board FPC1 is bent is referred to as a bending area BND. The area of ​​the flexible wiring board FPC1 folded back to the surface RF side of the display panel PNL is referred to as an area BSF.

[0036] The length (width) of the bending area BND along the second direction Y is defined as length db (refer to Figure 1 ). The smaller the bending area BND is, the narrower the frame can be achieved. That is, the smaller the length db is, the narrower the frame can be achieved. However, the smaller the length db is, the smaller the curvature is, and there is a concern that the flexible wiring substrate FPC1 may be disconnected.

[0037] Therefore, in the present embodiment, a reinforcing resin is provided in the bending region BND to reinforce the bending region BND.

[0038] Here, a display device according to a comparative example will be described. Figure 3 as well as Figure 4 It is a cross-sectional view showing an example of a schematic configuration of a display device according to a comparative example. Figure 3 is a cross-sectional view of the display device in a bent state. Figure 4 is a cross-sectional view of the display device in a state before being bent.

[0039] The display device DSP includes a substrate SUB1, a polarizing plate POL, an adhesive ADH, an anisotropic conductive film ACF, a flexible wiring board FPC1, a protection member UVR, a protection member PRS, a protection member FMT, a protection member DST, a protection member SRT, and a driver IC chip ICP.

[0040] The substrate SUB1, the polarizing plate POL, the adhesive ADH, the flexible wiring substrate FPC1, and the driver IC chip ICP constitute the display panel PNL. The flexible wiring substrate FPC1 includes a base material FPCB having flexibility and wiring FPCL.

[0041] exist Figure 3 In the display device DSP shown, the flexible wiring substrate FPC1 is bent in the bending area BND. More specifically, the bending area BND includes a flat area BNDF and a curvature area BNDR. The bending area BND can also be said to be an area protruding from the end ES11 of the substrate SUB1. By bending the flexible wiring substrate FPC1 in the bending area BND, the distance dh protruding from the end ES11 of the substrate SUB1 to the outside is reduced, and a narrow frame can be achieved.

[0042] A polarizer POL is attached to the substrate SUB1 by using an adhesive ADH. The adhesive ADH is, for example, an optical adhesive having light transmittance. The surface of the polarizer POL opposite to the surface facing the substrate SUB1 corresponds to the surface FF of the display panel PNL. The polarizer POL is, for example, a circular polarizer. By providing the polarizer POL, for example, it is possible to suppress the reflection of external light in the display area DA of the display panel PNL.

[0043] The surface of the substrate SUB1 that faces the polarizing plate POL is referred to as a surface FS. The surface opposite to the surface FS is referred to as a surface RS. The surface RS of the substrate SUB1 corresponds to the surface RF of the display panel PNL.

[0044] An anisotropic conductive film ACF is provided in the connection portion WPD in the area EA of the substrate SUB1. The wiring of the substrate SUB1 and the wiring FPCL of the flexible wiring substrate FPC1 are electrically connected via the anisotropic conductive film ACF.

[0045] In the area EA, a protective member UVR is provided between the end EP11 of the polarizing plate POL and the end EF11 of the flexible wiring board FPC1.

[0046] The protective member UVR may be made of, for example, a photocurable resin material. The protective member UVR is set so as not to form a gap with the polarizing plate POL. The protective member UVR is arranged for the purpose of preventing the wiring and electrode parts not covered by the polarizing plate POL or the anisotropic conductive film ACF from being affected by moisture.

[0047] The protection member FMT, the protection member DST, and the driver IC chip ICP are arranged along the direction opposite to the third direction Z between the substrate SUB1 and the region BSF of the flexible wiring substrate FPC1.

[0048] The protective member FMT is a protective member having adhesive tape on the surface and back of a substrate having buffering properties. In other words, the protective member FMT can be said to be a double-sided adhesive tape having buffering properties. The protective member DST is a member having an adhesive layer on the surface and the back, for example, a double-sided adhesive tape. In addition, the protective member DST may also have buffering properties.

[0049] The driver IC chip ICP and the region BSF of the flexible wiring substrate FPC1 provided on the substrate SUB1 are bonded by the protection member FMT and the protection member DST. The protection member FMT has the function of maintaining the interval between the bent flexible wiring substrate FPC1 and the driver IC chip ICP at a certain level or above by having a base material with buffering properties. Thus, even if pressure in the thickness direction (third direction Z) is applied to the flexible wiring substrate FPC1, the curvature of the bent region BND is maintained within an allowable range.

[0050] A protective member SRT is provided in contact with the wiring FPCL of the flexible wiring substrate FPC1. The protective member SRT is formed, for example, using a heat-resistant resin material, more specifically, using a so-called solder resist. The protective member SRT is provided in an area other than an area in contact with the anisotropic conductive film ACF and an area in contact with the driver IC chip ICP in the area where the wiring FPCL is provided. The wiring FPCL is protected by the protective member SRT.

[0051] The protection member PRS extends from the end ES11 of the substrate SUB1 along the second direction Y and overlaps a portion of the protection member SRT. Near the end ES11 of the substrate SUB1, a portion of the anisotropic conductive film ACF and a portion of the wiring FPCL are exposed. The protection member PRS protects the exposed portion of the anisotropic conductive film ACF and a portion of the wiring FPCL. If the protection member PRS is not provided, the exposed portion of the wiring FPCL will be damaged by the end ES11 of the substrate SUB1, and there is also a concern that the wiring FPCL will be broken. In addition, by providing the protection member PRS, the strength of the connection portion WPD can be ensured.

[0052] The protection member PRS may be made of, for example, a resin material. However, if the elastic modulus of the resin material is high, the flexible wiring board FPC1 is not easily bent. The length of the flat region BNDF in the bending region BND becomes longer, and the distance dh becomes longer.

[0053] Therefore, in this embodiment, a resin material with a low elastic modulus, for example, a resin material with an elastic modulus of 10 MPa or more and 20 MPa or less is used as the protection member PRS. If such a resin material with a low elastic modulus is used, when the flexible wiring substrate FPC1 is bent, the protection member PRS is crushed and bent together with the flexible wiring substrate FPC1. As a result, the distance dh that the flexible wiring substrate FPC1 protrudes outward from the end ES11 can be reduced. Therefore, the frame of the display device DSP can be narrowed.

[0054] Figure 5 as well as Figure 6 This is a cross-sectional view showing an example of a schematic configuration of a display device according to an embodiment. Figure 5 is a cross-sectional view of the display device in a bent state. Figure 6 is a cross-sectional view of the display device in a state before being bent. Figure 5 as well as Figure 6 The display device shown is Figure 3 as well as Figure 4 The display device shown in FIG. 1 is different from the display device shown in FIG. 1 in that a resin material having a low elastic modulus is used for the protection member PRS.

[0055] Figure 5 as well as Figure 6 The display device DSP shown is similar to the display device DSP shown in FIG. 1 except that the protection member PRS is made of a resin material with a low elastic modulus. Figure 3 as well as Figure 4 The display device DSP shown is the same. Figure 5 as well as Figure 6 The protection member PRS of the display device DSP shown in the figure is used in addition to the description Figure 3 as well as Figure 4 , thus omitting the description.

[0056] Comparative Example Protection Component PRS (refer to Figure 3 ) is also provided in the flat region BNDF in the region BND. On the other hand, the protection member PRS (see Figure 5 ) extends in a manner that overlaps not only the flat region BNDF in the region BND, but also overlaps a portion of the region BNDR having a curvature.

[0057] Since the protection member PRS of the present embodiment is formed of a resin material with a low elastic modulus, as described above, when the flexible wiring substrate FPC1 is bent, the protection member PRS is crushed and bent together. On the other hand, the protection member PRS of the comparative example has a high elastic modulus, and therefore does not bend together when the flexible wiring substrate FPC1 is bent. Therefore, the protection member PRS of the comparative example is not provided in the region BNDR having the curvature.

[0058] Figure 7 : is a graph showing the relationship between the elastic modulus of the protective member and the distance that the flexible wiring substrate protrudes outward from the end of the substrate. Figure 7 As shown, when a resin material having an elastic modulus of 50 MPa to 60 MPa is used as the protection member PRS, the distance dh becomes 0.3 mm to 0.5 mm.

[0059] On the other hand, if a resin material having an elastic modulus of 10 MPa to 20 MPa is used as the protection member PRS, the distance dh becomes 0.1 mm to 0.2 mm. Thus, the distance dh protruding from the end ES11 of the substrate SUB1 is reduced, thereby achieving a narrow frame of the display device DSP.

[0060] Here, the pixels PX of the display panel PNL are described in further detail.

[0061] Figure 8 : is a partial top view showing an example of a schematic structure of a display panel. A plurality of pixels PX include a pixel PXR that emits red, a pixel PXG that emits green, and a pixel PXB that emits blue. The pixel PXR, the pixel PXG, and the pixel PXB are also referred to as the first pixel, the second pixel, and the third pixel, respectively. The pixel PXR and the pixel PXB are adjacently arranged along the first direction X and the second direction Y. The pixel PXG and the pixel PXB are adjacently arranged along the first direction X and the second direction Y. The pixel PXB is adjacently arranged along the first direction to the pixel PXR, and adjacently arranged along the second direction Y to the pixel PXG.

[0062] Fig. 9 It is along Figure 8 A cross-sectional view of the display panel taken along line A1 - A2 is shown.

[0063] The base material BA1 is a base material having insulating properties, for example, glass.

[0064] An insulating layer UC1 is provided on the base material BA1. The insulating layer UC1 is formed of, for example, a silicon oxide film and a silicon nitride film as a single layer or as a stacked layer.

[0065] A light shielding layer BM may be provided on the insulating layer UC1 so as to overlap with the transistor Tr. The light shielding layer BM suppresses changes in transistor characteristics caused by light intrusion from the back side of the channel of the transistor Tr. When the light shielding layer BM is formed of a conductive layer, a predetermined potential is given, so that a back gate effect can also be given to the transistor Tr.

[0066] An insulating layer UC2 is provided to cover the insulating layer UC1 and the light shielding layer BM. As the material of the insulating layer UC2, the same material as that of the insulating layer UC1 can be used. The insulating layer UC2 can be made of a material different from that of the insulating layer UC1. For example, the insulating layer UC1 can be made of silicon oxide, and the insulating layer UC2 can be made of silicon nitride. The insulating layers UC1 and UC2 are collectively referred to as the insulating layer UC.

[0067] A transistor Tr is provided on the insulating layer UC. The transistor Tr includes a semiconductor layer SC, an insulating layer GI, a gate electrode GE (scanning line GL), an insulating layer ILI, a source electrode SE (signal line SL), and a drain electrode DE. The transistor Tr is a thin film transistor (TFT).

[0068] As the semiconductor layer SC, amorphous silicon, polycrystalline silicon, or an oxide semiconductor is used.

[0069] As the insulating layer GI, for example, silicon oxide or silicon nitride is provided in a single layer or in a stacked manner.

[0070] As the gate electrode GE, for example, molybdenum-tungsten alloy (MoW) is used. The gate electrode GE may be formed integrally with the scanning line GL.

[0071] The insulating layer ILI is provided so as to cover the semiconductor layer SC and the gate electrode GE. The insulating layer ILI is formed of, for example, a silicon oxide layer or a silicon nitride layer in a single layer or in a stacked manner.

[0072] A source electrode SE and a drain electrode DE are provided on the insulating layer ILI. The source electrode SE and the drain electrode DE are connected to the source region and the drain region of the semiconductor layer SC through contact holes provided in the insulating layer ILI and the insulating layer GI, respectively. The source electrode SE may be formed integrally with the signal line.

[0073] An insulating layer PAS is provided so as to cover the source electrode SE, the drain electrode DE, and the insulating layer ILI. An insulating layer PLL is provided so as to cover the insulating layer PAS.

[0074] The insulating layer PAS is formed using an inorganic insulating material. Examples of the inorganic insulating material include a single layer or a stacked layer of silicon oxide or silicon nitride. The insulating layer PLL is formed using an organic insulating material. Examples of the organic insulating material include a resin insulating material such as polyimide or acrylic. By providing the insulating layer PLL, the height difference caused by the transistor Tr can be flattened.

[0075] An anode AD is provided on the insulating layer PLL. The anode AD is connected to the drain electrode DE via a contact hole provided in the insulating layer PAS and PLL. The anode provided in the pixel PXR is referred to as the anode ADR, the anode provided in the pixel PXB is referred to as the anode ADB, and the anode provided in the pixel PXG is referred to as the anode ADG. When there is no need to distinguish between the anode ADR, the anode ADG, and the anode ADB, they are simply referred to as the anode AD.

[0076] The anode AD may be formed of a laminate of a reflective electrode and a transparent electrode. The reflective electrode is a conductive material with high reflectivity, such as silver (Ag) or aluminum (Al). The transparent electrode is formed of indium tin oxide (ITO) or indium zinc oxide (IZO).

[0077] In this embodiment, the structure from the base material BA1 to the insulating layer PLL is referred to as the back plate BPS.

[0078] Banks BK (also referred to as protrusions or ribs) are provided between adjacent anodes AD. The same organic material as that of insulating layer PLL is used as a material of banks BK. Banks BK are opened to expose a portion of anodes AD.

[0079] The opening provided in the pixel PXR is referred to as the opening OPR, the opening provided in the pixel PXB is referred to as the opening OPB, and the opening provided in the pixel PXG is referred to as the opening OPG. When there is no need to distinguish between the opening OPR, the opening OPB, and the opening OPG, they are simply referred to as the opening OP.

[0080] The end of the opening OP is preferably formed into a gently tapered shape in a plan view. If the end of the opening OP is formed into a steep shape, the organic EL layer ELY formed thereafter may have a problem of poor coverage.

[0081] An organic EL layer ELY is provided between adjacent banks BK, overlapping with the anode AD. The organic EL layer ELY includes a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. If necessary, the organic EL layer ELY may also include an electron blocking layer and a hole blocking layer.

[0082] The organic EL layer provided in the pixel PXR is referred to as the organic EL layer ELYR, the organic EL layer provided in the pixel PXB is referred to as the organic EL layer ELYB, and the organic EL layer provided in the pixel PXG is referred to as the organic EL layer ELYG. When there is no need to distinguish the organic EL layer ELYR, the organic EL layer ELYG, and the organic EL layer ELYB, they are simply referred to as the organic EL layer ELY.

[0083] A cathode CD is provided on the organic EL layer ELY. The cathode CD is formed using, for example, a magnesium-silver alloy (MgAg) film, a single-layer film of silver (Ag), a laminated film of silver (Ag) and a transparent conductive material, etc. The transparent conductive material may be, for example, indium tin oxide (ITO) or indium zinc oxide (IZO).

[0084] An insulating layer SEY is provided to cover the cathode CD. The insulating layer SEY has a function of preventing moisture from invading the organic EL layer ELY from the outside. As the insulating layer SEY, it is preferred to have high gas barrier properties. As the insulating layer SEY, for example, an insulating layer in which an organic insulating layer is sandwiched between two nitrogen-containing inorganic insulating layers is cited. As the material of the organic insulating layer, a resin insulating material of polyimide or acrylic is cited. As the material of the nitrogen-containing inorganic insulating layer, for example, silicon nitride and aluminum nitride are cited.

[0085] The light emitted from the organic EL layer ELY is taken out upward via the cathode CD. That is, the display device DSP (display panel PNL) of the present embodiment has a top emission structure.

[0086] Several embodiments of the present invention have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments or their modifications are included in the scope or spirit of the invention, and are included in the invention described in the scope of the claims and their equivalents.

Claims

1. A display device, characterized in that: have: A substrate including a display region having a plurality of pixels and an end region having a connection portion; A flexible wiring substrate including wiring and a flexible base material; A driver IC chip provided on the flexible wiring substrate; as well as a protective member extending from an end portion of the substrate and overlapping the wiring of the flexible wiring substrate, the flexible wiring substrate is bent in the bending region, The driver IC chip is opposite to the display area. The elastic modulus of the protection member is 10 MPa to 20 MPa.

2. The display device according to claim 1, characterized in that The curved region includes a flat region and a region having a curvature, The protection member overlaps the region having the curvature.

3. The display device according to claim 1, characterized in that A double-sided adhesive tape with buffering properties is provided between the driver IC chip and the display area.

4. The display device according to claim 1, characterized in that A polarizing plate is provided on the substrate.

5. The display device according to claim 1, characterized in that A heat-resistant resin is provided to cover the wiring of the flexible wiring substrate.

6. The display device according to claim 1, characterized in that: The wiring and the connection portion of the flexible wiring substrate are electrically connected via an anisotropic conductive film.

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