Touch sensor module, window stack structure, and image display device

Abstract

A touch sensor module, comprising: a touch sensor layer including a visible area, a curved area, and a pad area; a flexible printed circuit board electrically connected to the touch sensor layer on the pad area of the touch sensor layer; a support structure partially covering the flexible printed circuit board and the touch sensor layer; an optical layer disposed on the visible area of the touch sensor layer, the optical layer being spaced apart from the support structure in a horizontal direction such that a gap is formed between the optical layer and the support structure; a filling layer at least partially filling the gap; and an adhesive layer formed on a bottom surface of a part of the touch sensor layer in the visible area.

Description

[0001] Cross - reference to related applications and claim of priority

[0002] This application claims priority to Korean Patent Application No. 10 - 2019 - 0100066, filed on August 16, 2019 with the Korean Intellectual Property Office (KIPO), the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to a touch sensor module, a window stack structure including the touch sensor module, and an image display device including the touch sensor module. More specifically, the present invention relates to a touch sensor module including a sensing electrode and an insulating structure, a window stack structure including the touch sensor module, and an image display device including the touch sensor module.

[0004] Related Art

[0005] With the development of information technology, various demands for display devices having thinner dimensions, light weight, high power consumption efficiency, etc. are increasing. The display device may include a flat panel display device, such as a liquid crystal display (LCD) device, a plasma display panel (PDP) device, an electroluminescent display device, an organic light - emitting diode (OLED) display device, etc.

[0006] Touch panels or touch sensors that can input a user's instruction by selecting a command displayed on the screen with a finger or an input tool have also been developed. The touch panel or touch sensor may be combined with the display device, so that the display and information input functions can be implemented in one electronic device.

[0007] Since flexible displays that can be bent or folded are being developed, touch sensors having appropriate characteristics, structures, and configurations are also required to be applied to flexible displays. In addition, considering the connection reliability with a main board, a circuit board, etc. in the image display device, appropriate positional and structural designs of the touch sensor may be required. Summary of the Invention

[0008] According to an aspect of the present invention, there is provided a touch sensor module having improved electrical and mechanical reliability.

[0009] According to an aspect of the present invention, there is provided a window stack structure including a touch sensor module having improved electrical and mechanical reliability.

[0010] According to an aspect of the present invention, there is provided an image display device including a touch sensor module having improved electrical and mechanical reliability.

[0011] The above aspects of the present invention will be achieved by one or more of the following features or configurations:

[0012] (1) A touch sensor module, comprising: a touch sensor layer including a visible area, a curved area, and a pad area; a flexible circuit board electrically connected to the touch sensor layer on the pad area of the touch sensor layer; a support structure partially covering the flexible circuit board and the touch sensor layer; an optical layer disposed on the visible area of the touch sensor layer and spaced apart from the support structure in a horizontal direction such that a gap is formed between the optical layer and the support structure; a filling layer at least partially filling the gap; and an adhesive layer formed on a bottom surface of a part of the touch sensor layer in the visible area.

[0013] (2) The touch sensor module according to (1) above, wherein a top surface of the filling layer is lower than top surfaces of the optical layer and the support structure.

[0014] (3) The touch sensor module according to (1) above, wherein the filling layer partially covers the top surface of the support structure, and the top surface of the filling layer is lower than the top surface of the optical layer.

[0015] (4) The touch sensor module according to (1) above, wherein the touch sensor layer includes: sensing electrodes disposed on the visible area; and traces branching out from the sensing electrodes to extend to the curved area and the pad area.

[0016] (5) The touch sensor module according to (4) above, wherein ends of the traces are electrically connected to the flexible circuit board in the pad area.

[0017] (6) The touch sensor module according to (1) above, wherein the support structure partially covers the curved area of the touch sensor layer.

[0018] (7) The touch sensor module according to (6) above, wherein the filling layer covers a remaining part of the curved area.

[0019] (8) The touch sensor module according to (1) above, wherein the support structure includes a substrate layer and a support layer formed on the substrate layer, wherein the support layer includes an adhesive material and is in contact with the flexible circuit board and the touch sensor layer.

[0020] (9) The touch sensor module according to (1) above, wherein the filling layer includes an adhesive resin.

[0021] (10) The touch sensor module according to (1) above further includes a lower support structure formed on a bottom surface of a part of the touch sensor layer in the bending region.

[0022] (11) The touch sensor module according to (10) above, wherein the lower support structure includes a lower substrate layer and a lower support layer, the lower support layer is formed on the lower substrate layer and bonded to the bottom surface of the touch sensor layer, and the lower support layer includes an adhesive material.

[0023] (12) The touch sensor module according to (11) above, wherein a modulus of the lower substrate layer is greater than a modulus of the lower support layer.

[0024] (13) The touch sensor module according to (1) above, wherein the optical layer includes at least one selected from the group consisting of a polarizing plate, a polarizer, a retardation film, a reflective sheet, a brightness enhancement film, and a refractive index matching film.

[0025] (14) A window stack structure includes: a window substrate; and a touch sensor module according to the above-described embodiments, the touch sensor module being on a surface of the window substrate

[0026] (15) An image display device includes: a touch sensor module according to the above-described embodiments; and a display panel, the display panel being bonded to the touch sensor layer through the adhesive layer of the touch sensor module.

[0027] (16) The image display device according to (15) above further includes a main board below the display panel, wherein the touch sensor layer and the flexible circuit board of the touch sensor module are bent together with the support structure at the bending region to be electrically connected to the main board.

[0028] The touch sensor module according to an embodiment of the present invention may include a support structure that partially covers the touch sensor layer and the flexible printed circuit board. When the touch sensor module is folded or bent, delamination of the flexible printed circuit board can be prevented by the support structure, and damage to the sensing electrodes or traces in the bending region can also be prevented.

[0029] In some embodiments, the touch sensor module may further include an optical film disposed on the touch sensor layer. A gap may be formed between the support structure and the optical film, and a filling layer filling the gap may be formed. The filling layer may further improve the bonding strength or adhesiveness of the support structure and, additionally, avoid defects such as cracks in the bending region.

[0030] In some embodiments, an adhesive layer may be selectively formed only under a part of the touch sensor layer in the visible area, such that additional structures such as a display panel may be bonded in the visible area while maintaining the flexibility of the bending region.

[0031] The touch sensor module may be manufactured as a substrate-free film and may be effectively applied to an image display device such as a flexible display. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic cross-sectional view showing a touch sensor module according to an exemplary embodiment.

[0033] Figure 2 and Figure 3 is a schematic top plan view showing a touch sensor layer according to an exemplary embodiment.

[0034] Figures 4 to 6 is a schematic cross-sectional view showing a touch sensor module according to some exemplary embodiments.

[0035] Figure 7 is a schematic view showing a window stack structure and an image display device according to an exemplary embodiment.

[0036] Figure 8 is a schematic cross-sectional view showing an image display device incorporating a touch sensor module according to an exemplary embodiment. DETAILED DESCRIPTION

[0037] According to an exemplary embodiment of the present invention, there is provided a touch sensor module including a touch sensor layer, an optical layer, a flexible circuit board, and an adhesive structure, and having improved mechanical and electrical stability.

[0038] According to an exemplary embodiment of the present invention, there is also provided a window stack structure and an image display device including the touch sensor module.

[0039] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that such embodiments provided with reference to the accompanying drawings are for further understanding the spirit of the present invention and do not limit the subject matter to be protected as disclosed in the detailed description and the appended claims.

[0040] In the drawings, for example, two directions parallel to the top surface of the touch sensor layer and perpendicular to each other are defined as a first direction and a second direction. For example, the first direction may correspond to the length direction of the touch sensor module, and the second direction may correspond to the width direction of the touch sensor module. Additionally, a direction perpendicular to the first direction and the second direction may be defined as a third direction. For example, the third direction may correspond to the thickness direction of the touch sensor module.

[0041] Figure 1 is a schematic cross-sectional view showing a touch sensor module according to an exemplary embodiment.

[0042] Referring Figure 1 , the touch sensor module may include a touch sensor layer 100, an optical layer 150 and a flexible printed circuit board 160 disposed on the touch sensor layer 100, and a support structure 170 that partially covers the flexible printed circuit board 160 and the touch sensor layer 100. The touch sensor layer 100 may further include a filling layer 165 formed between the optical layer 150 and the support structure 170.

[0043] The touch sensor layer 100 may include, for example, a base insulating layer and sensing electrodes and traces formed on the base insulating layer. The elements and structure of the touch sensor layer 100 will be described in more detail with reference to Figure 2 and Figure 3 .

[0044] The touch sensor layer 100 or the touch sensor module may include a visible area VA, a bending area BA, and a pad area PA. The visible area VA may include a central area of the touch sensor layer 100, and the pad area PA may be located at one end of the touch sensor layer 100. The bending area BA may be located between the visible area VA and the pad area PA.

[0045] The visible area VA may include, for example, a display area of an image display device or an effective area that can sense a user's touch.

[0046] The flexible printed circuit board (FPCB) 160 may be disposed on a part of the touch sensor layer 100 in the pad area PA and may be electrically connected to the traces included in the touch sensor layer 100. The pad portions formed at the ends of the traces and the circuit wirings included in the flexible printed circuit board 160 may be electrically connected to each other through a conductive intermediate structure such as an anisotropic conductive film (ACF).

[0047] The flexible printed circuit board 160 may include, for example, a core layer including a resin or a liquid crystal polymer, and circuit wirings printed on the core layer. The flexible printed circuit board 160 may further include a cover film covering the circuit wirings. A part of the cover film may be removed to expose a part of the circuit wirings that can be connected to the pad portions.

[0048] The touch sensor layer 100 may further include a passivation layer that can protect the sensing electrodes and traces. In this case, a part of the passivation layer formed in the pad area PA connected to the flexible circuit board 160 may be removed.

[0049] The support structure 170 may be formed on or attached to the flexible circuit board 160 in the pad area PA, and may extend to the bending area BA to partially cover the touch sensor layer 100. Thus, the support structure 170 may commonly and partially cover the touch sensor layer 100 and the end portion of the flexible circuit board 160.

[0050] The support structure 170 may be used as a protection pattern to prevent damage to the sensing electrodes and traces, such as delamination, cracks, etc., caused when the flexible circuit board 160 is separated, folded, or bent due to external stress in the bending area BA.

[0051] The support structure 170 may have a multi-layer structure. For example, the support structure 170 may include a substrate layer 172 and a support layer 174 formed on the surface of the substrate layer 172. The support layer 174 may include, for example, an adhesive material based on acrylic, silicone, urethane, and / or rubber, and may commonly hold the flexible circuit board 160 and the touch sensor layer 100 in the bending area BA and the pad area PA.

[0052] The substrate layer 172 may include a polymer material having a modulus or elasticity greater than that of the support layer 174. For example, the substrate layer 172 may include a polymer film containing: cyclic olefin polymer (COP), polyethylene terephthalate (PET), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polyallylate, polyimide (PI), polyurethane (PU), cellulose acetate propionate (CAP), polyethersulfone (PES), triacetyl cellulose (TAC), polycarbonate (PC), cyclic olefin copolymer (COC), polymethyl methacrylate (PMMA), etc.

[0053] For example, the support structure 170 may have a strip shape, which includes a support layer 174 formed by coating an adhesive material on the substrate layer 172.

[0054] The touch sensor module may further include an optical layer 150. The optical layer 150 may include a film or layer structure well-known in the related art for improving the image visibility of an image display device. Non-limiting examples of the optical layer 150 may include a polarizing plate, a polarizer, a retardation film, a reflective sheet, a brightness enhancement film, a refractive index matching film, etc. These may be used alone or in a multi-layer structure.

[0055] In an exemplary embodiment, the optical layer 150 may be located at substantially the same layer or the same level as the layer of the support structure 170, and may cover the visible area VA of the touch sensor layer 100.

[0056] In some embodiments, the optical layer 150 and the support structure 170 may be horizontally spaced apart from each other by a predetermined distance on the bending region BA. Accordingly, a gap 155 may be formed between the optical layer 150 and the support structure 170. For example, the gap 155 may be used as a margin area for the alignment of the support structure 170.

[0057] In an exemplary embodiment, a filling layer 165 that fills the gap 155 may be formed. The filling layer 165 may at least partially fill the gap 155, and may contact the top surface of the touch sensor layer 100 as well as the sidewalls of the optical layer 150 and the support structure 170.

[0058] In some embodiments, the top surface of the filling layer 165 may be lower than the respective top surfaces of the optical layer 150 and the support structure 170.

[0059] The filling layer 165 may be formed by filling an adhesive resin composition in the gap 155 and then curing at room temperature, by heat curing, or by ultraviolet curing. The resin composition may include an acrylic resin, a silicone resin, a urethane resin, and / or a rubber resin. In one embodiment, the resin composition may further include a solvent, a photopolymerizable monomer, a polymerization initiator, a curing agent, etc.

[0060] As described above, when attaching the support structure 170, an alignment margin may be obtained in advance through the gap 155 to prevent contact with the optical layer 150. Subsequently, the filling layer 165 may be formed by filling a resin composition in the gap 155. Accordingly, the exposed area of the touch sensor layer 100 may be reduced by the filling layer 165, and the sensing electrodes may be further protected. In addition, the filling layer 165 may contact and hold the sidewalls of the optical layer 150 and the support structure 170, thereby suppressing peeling and lift of the support structure 170 and the optical layer 150.

[0061] In some embodiments, the viscosity of the filling layer 165 at room temperature (25 °C) may be about 1,000 cP to about 5,000 cP, preferably about 1,000 cP to about 4,000 cP. The filling layer 165 may substantially fill the gap 155 within the above viscosity range to prevent the outflow of the resin material.

[0062] In some embodiments, the tensile modulus of the filling layer 165 may be about 5 MPa to 3,500 MPa, preferably about 1,000 MPa to 3,500 MPa. Within this range of tensile modulus, damage to the sensing electrodes in the bending region of the touch sensor module can be effectively suppressed.

[0063] In some embodiments, the adhesion force of the filling layer 165 to the contact surface with the touch sensor layer 100 may be about 2 N / 25 mm or greater, and preferably about 5 N / 25 mm or greater. In this case, when the touch sensor module is bent, separation of the filling layer 165 from the electrodes of the touch sensor layer 100 can be sufficiently suppressed.

[0064] The thickness of the filling layer 165 can be adjusted to meet the above ranges of viscosity, tensile modulus, and adhesion force, and the thickness of the filling layer 165 can be, for example, in the range of about 20 μm to about 100 μm.

[0065] In some embodiments, an adhesive layer for bonding the optical layer 150 may also be formed on the top surface of the touch sensor layer 100 in the visible area VA.

[0066] An adhesive layer 80 may be formed on the bottom surface of the touch sensor layer 100 in the visible area VA. In an exemplary embodiment, the adhesive layer 80 may be formed in the visible area VA and may not extend to the bending region BA. Accordingly, additional structures such as a display panel can be combined in the visible area VA while facilitating the bending operation in the bending region BA.

[0067] Figure 2 and Figure 3 is a schematic top plan view showing a touch sensor layer according to an exemplary embodiment.

[0068] Refer to Figure 2 , the touch sensor layer 100 may include a base insulating layer 90, and sensing electrodes 110 and 120 and traces 130 and 135 disposed on the base insulating layer 90. In an exemplary embodiment, the sensing electrodes 110 and 120 may be arranged to be operable by a mutual capacitance type. The base insulating layer 90 may serve as a base layer or a support layer for forming the sensing electrodes 110 and 120 and the traces 130 and 135.

[0069] The sensing electrodes 110 and 120 may be disposed in the visible area VA of the touch sensor layer 100. In an exemplary embodiment, the sensing electrodes 110 and 120 may include a first sensing electrode 110 and a second sensing electrode 120.

[0070] The first sensing electrode 110 may be arranged, for example, along a second direction (e.g., the width direction). Thus, a row of first sensing electrodes 110 extending along the second direction may be formed by a plurality of first sensing electrodes 110. A plurality of such rows of first sensing electrodes may be arranged along the first direction.

[0071] In some embodiments, the first sensing electrodes 110 adjacent to each other along the second direction may be physically or electrically connected to each other through a connection part 115. For example, the connection part 115 may be integrally formed with the first sensing electrode 110 at the same level as the first sensing electrode 110.

[0072] The second sensing electrode 120 may be arranged along the first direction (e.g., the length direction). In some embodiments, the second sensing electrodes 120 may each be physically separated into island-shaped unit electrodes. In this case, the second sensing electrodes 120 adjacent to each other along the first direction may be electrically connected to each other through a bridging electrode 125.

[0073] A plurality of second sensing electrodes 120 may be connected to each other through the bridging electrode 125 and may be arranged along the first direction such that a column of second sensing electrodes extending along the first direction may be formed. In addition, a plurality of such columns of second sensing electrodes may be arranged along the second direction.

[0074] The sensing electrodes 110 and 120 and / or the bridging electrode 125 may include a metal, an alloy, or a transparent conductive oxide.

[0075] For example, the sensing electrodes 110 and 120 and / or the bridging electrode 125 may be formed of silver (Ag), gold (Au), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), titanium (Ti), tungsten (W), niobium (Nb), tantalum (Ta), vanadium (V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), tin (Sn), zinc (Zn), molybdenum (Mo), calcium (Ca), or an alloy thereof (e.g., a silver-palladium-copper (APC) alloy or a copper-calcium (CuCa) alloy). These may be used alone or in combination thereof.

[0076] The sensing electrodes 110 and 120 and / or the bridging electrode 125 may include a transparent conductive oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), cadmium tin oxide (CTO), etc.

[0077] In some embodiments, the sensing electrodes 110 and 120 and / or the bridging electrode 125 may have a multi-layer structure including a transparent conductive oxide layer and a metal layer. For example, the sensing electrodes 110 and 120 and / or the bridging electrode 125 may have a three-layer structure of a transparent conductive oxide layer - metal layer - transparent conductive oxide layer. In this case, flexibility can be improved by the metal layer and resistance can be reduced, and corrosion resistance and transparency can be improved by the transparent conductive oxide layer.

[0078] In some embodiments, the bridging electrode 125 may be formed on an insulating layer (not shown). The insulating layer may at least partially cover the connection portion 115 included in the first sensing electrode 110, and at least partially cover the second sensing electrode 120 around the connection portion 115. The bridging electrode 125 may penetrate the insulating layer and may be electrically connected to the second sensing electrode 120 adjacent to each other with the connection portion 115 interposed therebetween.

[0079] The insulating layer may include an inorganic insulating material such as silicon dioxide or silicon nitride, or an organic insulating material such as an acrylic resin or a silicone resin.

[0080] The traces 130 and 135 may include first traces 130 extending from each of the first sensing electrode rows and second traces 135 extending from each of the second sensing electrode columns.

[0081] As Figure 2 shown, the traces 130 and 135 may extend from the periphery of the visible area VA and may be converged in the pad area PA via the bending area BA.

[0082] For example, the first trace 130 may branch from each of the first sensing electrode rows from two side portions of the touch sensor layer 100 and may extend in a first direction. The first trace 130 may bend when entering the bending area BA to extend in a second direction. The first trace 130 may bend again in the first direction to extend in the first direction in the pad area PA.

[0083] In some embodiments, the first traces 130 may be alternately distributed on two side portions of the touch sensor layer. The first traces 130 may be evenly distributed on two side portions of the touch sensor layer such that stress generated during a bending operation as described below may be evenly dispersed. Additionally, the first traces 130 may be alternately arranged on the two side portions, thereby increasing the alignment margin between adjacent first traces 130.

[0084] The second traces 135 may each branch from each second sensing electrode column and may extend in a second direction in the bending area BA. The second traces 135 may bend again in the first direction to extend in the first direction to the pad area PA.

[0085] The ends of the traces 130 and 135 can be used as pad portions that can be gathered in the pad region PA and electrically connected to the flexible circuit board 160. The first pad portion 140 and the second pad portion 145 can be defined by the ends of the first trace 130 and the second trace 135, respectively, and can be arranged in the pad region PA.

[0086] The traces 130 and 135 can include a conductive material that is substantially the same as or similar to the conductive material of the sensing electrodes 110 and 120.

[0087] In an exemplary embodiment, the flexible circuit board 160 can be electrically connected to the pad portions 140 and 145 on the pad region PA. In some embodiments, a conductive intermediate structure such as an anisotropic conductive film (ACF) can be arranged between the flexible circuit board 160 and the pad portions 140 and 145.

[0088] As referred to Figure 1 As described, the support structure 170 can commonly cover the bending region BA and the pad region PA in a plan view. The adhesion between the flexible circuit board 160 and the touch sensor layer 100 can be enhanced by the support structure 170, thereby preventing mechanical failures such as separation of the flexible circuit board 160 and / or the traces 130 and 135.

[0089] As described above, the support structure 170 can partially cover the bending region BA, and a gap 155 can be formed between the optical layer 150 and the support structure 170. For example, the filling layer 165 can fill the remaining region of the bending region BA..

[0090] The support structure 170 can be arranged on the bending region BA to cover portions of the traces 130 and 135, so that when folding or bending occurs, mechanical defects such as breakage or peeling of the traces 130 and 135 can be suppressed. Additionally, the filling layer 165 can fill the remaining region of the bending region BA, thereby further improving the mechanical stability of the traces 130 and 135.

[0091] Referring to Figure 3 , the sensing electrode 127 and the trace 137 of the touch sensor layer can be arranged to operate in a self-capacitance type.

[0092] The touch sensor layer can include sensing electrodes 127, and each sensing electrode can be set as an independent island pattern. Additionally, the trace 137 can branch from each sensing electrode 127 to extend to the pad region PA. The ends of the trace 137 can be gathered in the pad region PA and can be electrically connected to the flexible circuit board 160.

[0093] As described above, the support structure 170 may commonly cover the touch sensor layer 100 and the flexible circuit board 160 on the pad region PA and the bending region BA. Additionally, as described above, the remaining portion of the bending region BA may be filled with the filling layer 165.

[0094] Figures 4 to 6 is a schematic cross-sectional view showing a touch sensor module according to some exemplary embodiments. Details of elements and / or structures that are substantially the same or similar to those described with reference Figure 1 are omitted herein.

[0095] Reference Figure 4 , the filling layer 165 may fill the gap 155 and may also partially cover the top surface of the support structure 170. Accordingly, when the flexible circuit board 160 and the touch sensor layer 100 are bent, the support structure 170 can be fixed more stably.

[0096] The top surface of the filling layer 165 may be lower than the top surface of the optical layer 150. Thus, the filling layer 165 may not cover the top surface of the optical layer 150 to prevent the properties of the optical layer 150 from being disturbed by the filling layer 165.

[0097] Reference Figure 5 , the lower support structure 85 may be bonded to the bottom surface of the touch sensor layer 100 in the bending region BA and the pad region PA.

[0098] In some embodiments, the lower support structure 85 may have a structure and configuration that are substantially the same or similar to those of the support structure 170. For example, the lower support structure 85 may include a lower substrate layer 81 and a lower support layer 83 including an adhesive material, and the lower support layer 83 may be attached to the bottom surface of the touch sensor layer 100.

[0099] An adhesive layer 80 may be formed on the bottom surface of the touch sensor layer 100 in the visible area VA, and the lower support structure 85 may be formed on the bottom surface in the bending region BA. Accordingly, bending stability may be obtained through the lower substrate layer 81 having a relatively improved modulus, and additional structures such as a display panel may be combined through the adhesive layer 80.

[0100] Reference Figure 6 , as described above, the touch sensor module may be coupled to the display panel 200 through the adhesive layer 80 in the visible area VA.

[0101] In some embodiments, as described with reference Figure 5 , the lower support structure 85 may be bonded under the touch sensor layer 100 in the bending region BA and the pad region PA.

[0102] Figure 7 is a schematic diagram showing a window stack structure and an image display device according to an exemplary embodiment.

[0103] Referring to Figure 7 , the window stack structure 190 may include a window substrate 180 and a touch sensor module according to the above exemplary embodiment. The touch sensor module may include, for example, a touch sensor layer 100 and an optical layer 150 stacked on the visible area VA of the touch sensor layer 100, as shown in Figures 1 to 6 described. For ease of description, the illustration of the support structure 170 and the flexible circuit board 160 is omitted in Figure 7 , and a more detailed description thereof will be made with reference to Figure 8 .

[0104] The window substrate 180 may include, for example, a hard coat film or thin glass or ultra-thin glass (e.g., ultra-thin glass (UTG)). In one embodiment, a light-shielding pattern 185 may be formed on the peripheral portion of one surface of the window substrate 180. The light-shielding pattern 185 may include, for example, a color printing pattern and may have a single-layer or multi-layer structure. The border portion or non-display area of the image display device may be defined by the light-shielding pattern 185.

[0105] The optical layer 150 may include various optical films or optical structures included in the image display device. In some embodiments, the optical layer 150 may include a coating-type polarizer or a polarizing plate. The coating-type polarizer may include a liquid crystal coating, and the liquid crystal coating may include a crosslinkable liquid crystal compound and a dichroic dye. In this case, the optical layer 150 may include an alignment layer for providing the alignment of the liquid crystal coating.

[0106] For example, the polarizing plate may include a polyvinyl alcohol-based polarizer and a protective film attached to at least one surface of the polyvinyl alcohol-based polarizer.

[0107] The optical layer 150 may be directly attached to the surface of the window substrate 180 or may be attached via a first adhesive layer 60.

[0108] The touch sensor layer 100 may be included in the window stack structure 190 as a film or a panel. In one embodiment, the touch sensor layer 100 may be bonded to the optical layer 150 via a second adhesive layer 70.

[0109] As shown in Figure 7 , the window substrate 180, the optical layer 150, and the touch sensor layer 100 may be sequentially positioned from the viewer side. In this case, the sensing electrodes of the touch sensor layer 100 may be disposed below the optical layer 150 including the polarizer or the polarizing plate, so that the viewer can be effectively prevented from seeing the electrode pattern.

[0110] The image display device may include a display panel 200 and a window stack structure 190 disposed on the display panel. The window stack structure 190 may include a touch sensor module according to an exemplary embodiment.

[0111] The display panel 200 may include a pixel electrode 210, a pixel defining layer 220, a display layer 230, a counter electrode 240, and a encapsulation layer 250 disposed on a panel substrate 205.

[0112] The panel substrate 205 may include a flexible resin material. In this case, the image display device may be a flexible display.

[0113] A pixel circuit including a thin film transistor (TFT) may be formed on the panel substrate 205, and an insulating layer may be formed to cover the pixel circuit. The pixel electrode 210 may be electrically connected to the drain of the TFT, for example, on the insulating layer.

[0114] The pixel defining layer 220 may be formed on the insulating layer, and the pixel electrode 210 may be exposed through the pixel defining layer 220, thereby defining a pixel region. The display layer 230 may be formed on the pixel electrode 210, and the display layer 230 may include, for example, a liquid crystal layer or an organic light emitting layer.

[0115] The counter electrode 240 may be disposed on the pixel defining layer 220 and the display layer 230. The counter electrode 240 may be used as, for example, a common electrode or a cathode of the image display device. The encapsulation layer 250 may be disposed on the counter electrode 240 to protect the display panel 200.

[0116] As described with reference to Figure 6 As described, the display panel 200 may be bonded to the touch sensor layer 100 through an adhesive layer 80. For example, the thickness of the adhesive layer 80 may be greater than the thicknesses of the first adhesive layer 60 and the second adhesive layer 70, respectively. In a temperature range of -20°C to 80°C, the viscoelasticity of the adhesive layer 80 may be about 0.2 MPa or less. In this case, noise from the display panel 200 may be blocked, and interfacial stress during bending may be reduced, thereby avoiding damage to the window stack structure 190. In one embodiment, the viscoelasticity of the adhesive layer 80 may be in the range of about 0.01 MPa to about 0.15 MPa.

[0117] Figure 8 is a schematic cross-sectional view of an image display device incorporating a touch sensor module according to an exemplary embodiment. For example, Figure 8 shows the connection of the driving circuit of the touch sensor module via a flexible circuit board.

[0118] Reference Figure 8, The image display device includes a display panel 200 and a main board 300, and may include a touch sensor module according to the exemplary embodiments described above. The touch sensor module may include a touch sensor layer 100 and an optical layer 150 disposed on the visible area VA of the touch sensor layer 100.

[0119] As referred to Figure 1 above, it may be bent starting from the bending area BA of the touch sensor layer 100, and the bending may be performed in the third direction along the first direction (e.g., the thickness direction of the image display device). Thus, the pad portions of the traces included in the pad area PA may be electrically connected to the main board 300 via the flexible circuit board 160. The flexible circuit board 160 may be connected to, for example, a bonding pad 350 formed on the bottom surface of the main board 300.

[0120] In one embodiment, the end portion (e.g., the pad area PA and / or the bending area BA) of the touch sensor module or the touch sensor layer 100 may be bent 180 degrees ( o ) or more. Thus, the end portion may extend again along the first direction. The end portion may face the non-bent portion of the touch sensor layer 100 portion in the third direction.

[0121] As described above, even when severe bending is applied, the support structure 170 may fix the combination between the flexible circuit board 160 and the touch sensor layer 100, thereby suppressing breakage, separation, etc. of circuits, wirings, electrodes, etc. In addition, a filling layer 165 may be formed between the optical layer 150 and the support structure 170, thereby preventing mechanical damage such as cracks in the sensing electrodes in the bending start area.

[0122] For example, in the touch sensor module according to the exemplary embodiments, even when the bending radius is 0.2R or more, cracks in the traces may be prevented. Preferably, even when the bending radius is 1R or more, the mechanical and operational reliability of the traces may be maintained.

Claims

1. A touch sensor module, comprising: A touch sensor layer, the touch sensor layer including a visible area, a bending area, and a pad area; A flexible printed circuit board, the flexible printed circuit board being electrically connected to the touch sensor layer on the pad area of the touch sensor layer; A support structure, the support structure partially covering the flexible printed circuit board and the touch sensor layer; An optical layer, the optical layer being disposed on the visible area of the touch sensor layer, the optical layer being spaced apart from the support structure in a horizontal direction such that a gap is formed between the optical layer and the support structure; A filling layer, the filling layer at least partially filling the gap; And An adhesive layer, the adhesive layer being formed on a bottom surface of a part of the touch sensor layer in the visible area, Wherein the support structure partially covers the bending area of the touch sensor layer and does not cover the visible area of the touch sensor layer, and the filling layer is spaced apart from the flexible printed circuit board in the horizontal direction, and the support structure is between the filling layer and the flexible printed circuit board.

2. The touch sensor module according to claim 1, wherein, A top surface of the filling layer is lower than top surfaces of the optical layer and the support structure.

3. The touch sensor module according to claim 1, wherein, The filling layer partially covers the top surface of the support structure, and the top surface of the filling layer is lower than the top surface of the optical layer.

4. The touch sensor module according to claim 1, wherein, The touch sensor layer includes: Sensing electrodes, the sensing electrodes being disposed on the visible area; and Traces, the traces branching out from the sensing electrodes and extending to the bending area and the pad area.

5. The touch sensor module according to claim 4, wherein, Ends of the traces are electrically connected to the flexible printed circuit board in the pad area.

6. The touch sensor module according to claim 1, wherein The filling layer covers a remaining portion of the bending area.

7. The touch sensor module according to claim 1, wherein, The support structure includes a substrate layer and a support layer formed on the substrate layer, Wherein the support layer includes an adhesive material, and the support layer contacts the flexible printed circuit board and the touch sensor layer.

8. The touch sensor module according to claim 1, wherein, The filling layer includes an adhesive resin.

9. The touch sensor module according to claim 1, further comprising a lower support structure, the lower support structure being formed on a bottom surface of a part of the touch sensor layer in the bending area.

10. The touch sensor module according to claim 9, wherein, The lower support structure includes a lower substrate layer and a lower support layer, the lower support layer being formed on the lower substrate layer and bonded to the bottom surface of the touch sensor layer, and the lower support layer includes an adhesive material.

11. The touch sensor module according to claim 10, wherein, A modulus of the lower substrate layer is greater than a modulus of the lower support layer.

12. The touch sensor module according to claim 1, wherein, The optical layer includes at least one selected from the group consisting of a polarizing plate, a polarizer, a retardation film, a reflector, a brightness enhancement film, and a refractive index matching film.

13. A window stack structure, comprising: A window substrate; And The touch sensor module according to claim 1, the touch sensor module being on a surface of the window substrate.

14. An image display device, comprising: The touch sensor module according to claim 1; And A display panel, the display panel being bonded to the touch sensor layer through the adhesive layer of the touch sensor module.

15. The image display device according to claim 14 further includes a main board below the display panel, Among them, wherein the touch sensor layer and the flexible circuit board of the touch sensor module are bent together with the support structure at the bending area to be electrically connected to the main board.

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