Module, laminate for image display device, image display device and method for manufacturing module

Abstract

To provide a module, an image display device laminate, an image display device, and a module manufacturing method that suppress deterioration in electrical connectivity between a power feeding section and a power feeding line.SOLUTION: In an image display device, a module 80A includes: a wiring board 10 having a board 11 including a first surface 11a and a second surface 11b located on the opposite side of the first surface 11a, a mesh wiring section 20 arranged on the first surface 11a of the board 11, and a power feeding section 40 electrically connected to the mesh wiring section 20; and a power feeding line 85 electrically connected to the power feeding section 40 via an anisotropic conductive film 85c containing a plurality of conductive particles 85d. The wiring board 10 has an electromagnetic wave transmitting and receiving function. The board 11 has transparency. The mesh wiring section 20 functions as an antenna. The average particle diameter of the conductive particles 85d is 3 μm or more and 20 μm or less.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] TECHNICAL FIELD Embodiments of the present disclosure relate to a module, a laminate for an image display device, an image display device, and a method for manufacturing a module. [Background technology]

[0002] Currently, mobile terminal devices such as smartphones and tablets are becoming increasingly sophisticated, smaller, thinner, and lighter. These mobile terminal devices use multiple communication bands, requiring multiple antennas corresponding to the communication bands. For example, mobile terminal devices are equipped with multiple antennas, such as a telephone antenna, a Wi-Fi (Wireless Fidelity) antenna, a 3G (Generation) antenna, a 4G (Generation) antenna, an LTE (Long Term Evolution) antenna, a Bluetooth (registered trademark) antenna, and an NFC (Near Field Communication) antenna. However, as mobile terminal devices become smaller, the space available for antenna installation is limited, limiting the degree of freedom in antenna design. Furthermore, because antennas are built into a limited space, radio wave sensitivity is not always satisfactory.

[0003] For this reason, film antennas that can be mounted in the display area of ​​mobile terminal devices have been developed. These film antennas are transparent antennas in which an antenna pattern is formed on a transparent substrate, and the antenna pattern is formed by a mesh-like conductive mesh layer that consists of conductor portions as formed portions of an opaque conductive layer and numerous openings as non-formed portions. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-66610 [Patent Document 2] Patent No. 5636735 specification [Patent Document 3] Patent No. 5695947 specification Summary of the Invention [Problem to be solved by the invention]

[0005] In a film antenna, a power supply line is connected to a power supply section for electrically connecting the conductive mesh layer to an external device, and in this case, it is required to suppress deterioration of the electrical connectivity between the power supply section and the power supply line.

[0006] The present embodiment aims to provide a module, a laminate for an image display device, an image display device, and a method for manufacturing a module that can suppress deterioration of electrical connectivity between a power supply line and a power supply section. [Means for solving the problem]

[0007] A first aspect of the present disclosure is a module comprising: a substrate including a first surface and a second surface located opposite the first surface; a wiring board having a mesh wiring portion disposed on the first surface of the substrate and a power supply portion electrically connected to the mesh wiring portion; and a power supply line electrically connected to the power supply portion via an anisotropic conductive film containing a plurality of conductive particles; the wiring board has an electromagnetic wave transmitting and receiving function; the substrate is transparent; the mesh wiring portion is configured as an antenna; and the average particle diameter of the conductive particles is 3 μm or more and 20 μm or less.

[0008] A second aspect of the present disclosure is a module according to the first aspect described above, wherein, among the plurality of conductive particles, 20% of the total number of the conductive particles, in order from the largest particle diameter, and 20% of the total number of the conductive particles, in order from the smallest particle diameter, are excluded, and for the remaining 60% of the conductive particles, the value obtained by subtracting the maximum particle diameter from the minimum particle diameter may be 60% or less of the average particle diameter.

[0009] A third aspect of the present disclosure is a module according to the first aspect or the second aspect described above, wherein the wiring board may have a millimeter wave transmitting and receiving function, and the mesh wiring portion may be configured as an array antenna.

[0010] A fourth aspect of the present disclosure is a module according to any one of the first to third aspects, wherein the anisotropic conductive film may have a thickness of 3 μm or more and 20 μm or less.

[0011] A fifth aspect of the present disclosure is a module according to each of the first to fourth aspects described above, wherein a first oxide film may be formed on the surface of the power supply portion, and the conductive particles may penetrate the first oxide film.

[0012] A sixth aspect of the present disclosure is a module according to each of the first to fifth aspects described above, wherein the power supply line may have a substrate and a metal wiring portion laminated on the substrate, a second oxide film may be formed on the surface of the metal wiring portion, and the conductive particles may penetrate the second oxide film.

[0013] A seventh aspect of the present disclosure is a module according to each of the first to sixth aspects described above, wherein the distance between the mesh wiring portions may be 1 mm or more and 5 mm or less.

[0014] An eighth aspect of the present disclosure is that in a module according to each of the first aspect to the seventh aspect described above, a dummy wiring section that is electrically independent from the mesh wiring section may be provided around the mesh wiring section.

[0015] A ninth aspect of the present disclosure is that, in a module according to the eighth aspect described above, a plurality of the dummy wiring sections may be provided, and the aperture ratio of the mesh wiring section and the dummy wiring section may increase stepwise from the mesh wiring section to the dummy wiring section farther from the mesh wiring section.

[0016] A tenth aspect of the present disclosure is a laminate for an image display device, comprising a module according to each of the first to ninth aspects described above, a first adhesive layer located on the first surface side of the substrate, and a second adhesive layer located on the second surface side of the substrate, wherein a portion of the substrate is disposed in a portion between the first adhesive layer and the second adhesive layer.

[0017] An eleventh aspect of the present disclosure is an image display device including the laminate for an image display device according to the tenth aspect described above, and a display device laminated on the laminate for an image display device.

[0018] A twelfth aspect of the present disclosure is a method for manufacturing a module, comprising the steps of: preparing a substrate including a first surface and a second surface located opposite the first surface; fabricating a wiring board by forming a mesh wiring portion and a power supply portion electrically connected to the mesh wiring portion on the first surface of the substrate; and electrically connecting a power supply line to the power supply portion via an anisotropic conductive film including a plurality of conductive particles, wherein the wiring board has an electromagnetic wave transmission / reception function, the substrate is transparent, the mesh wiring portion is configured as an antenna, and the average particle diameter of the conductive particles is 3 μm or more and 20 μm or less. [Effects of the Invention]

[0019] According to the embodiment of the present disclosure, it is possible to suppress a decrease in electrical connectivity between the power feed line and the power feed unit. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a plan view showing an image display device according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view (cross-sectional view taken along line II-II in FIG. 1) showing the image display device according to the embodiment. [Figure 3] FIG. 3 is a plan view showing the wiring board according to the embodiment. [Figure 4]FIG. 4 is an enlarged plan view showing a mesh wiring portion of a wiring board according to an embodiment. [Figure 5] FIG. 5 is a cross-sectional view (cross-sectional view taken along line VV in FIG. 4) showing the wiring board according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view (a cross-sectional view taken along line VI-VI in FIG. 4) showing the wiring board according to the embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a module according to one embodiment. [Figure 8] 8(a) to 8(f) are cross-sectional views showing a method for manufacturing a wiring board according to one embodiment. [Figure 9] 9(a) to 9(c) are cross-sectional views showing a method for manufacturing a module according to one embodiment. [Figure 10] 10(a) to 10(c) are cross-sectional views showing a method for manufacturing a laminate for an image display device according to one embodiment. [Figure 11] FIG. 11 is a plan view showing a wiring board according to a first modified example. [Figure 12] FIG. 12 is an enlarged plan view showing a wiring board according to a first modified example. [Figure 13] FIG. 13 is a plan view showing a wiring board according to a second modified example. [Figure 14] FIG. 14 is an enlarged plan view showing a wiring board according to a second modified example. [Figure 15] FIG. 15 is an enlarged plan view showing a mesh wiring portion of a wiring board according to a third modified example. DETAILED DESCRIPTION OF THE INVENTION

[0021] First, one embodiment will be described with reference to Figures 1 to 10. Figures 1 to 10 are diagrams showing this embodiment.

[0022] The figures shown below are schematic diagrams. Therefore, the size and shape of each part are appropriately exaggerated for ease of understanding. Furthermore, appropriate modifications can be made within the scope of the technical concept. In the figures shown below, the same parts are denoted by the same reference numerals, and some detailed descriptions may be omitted. Furthermore, the numerical values, such as dimensions, and material names of each component described in this specification are examples of embodiments, and are not limited to these and may be selected and used as appropriate. In this specification, terms specifying shapes or geometric conditions, such as parallel, orthogonal, and perpendicular, are interpreted not only to mean their strict meanings but also to include substantially the same state.

[0023] In the following embodiments, the "X direction" refers to a direction parallel to one side of the image display device. The "Y direction" refers to a direction perpendicular to the X direction and parallel to another side of the image display device. The "Z direction" refers to a direction perpendicular to both the X and Y directions and parallel to the thickness direction of the image display device. The "front surface" refers to the surface on the positive side of the Z direction, which is the light-emitting surface side of the image display device and faces the viewer. The "rear surface" refers to the surface on the negative side of the Z direction, which is the surface opposite to the light-emitting surface of the image display device and the surface facing the viewer. Note that in the present embodiment, the mesh wiring unit 20 will be described as having a radio wave transmitting and receiving function (functioning as an antenna), but the mesh wiring unit 20 does not necessarily have to have a radio wave transmitting and receiving function (functioning as an antenna).

[0024] The configuration of the image display device according to this embodiment will be described with reference to FIGS.

[0025] 1 and 2, an image display device 60 according to the present embodiment includes a laminate 70 for an image display device, and a display device 61 laminated on the laminate 70 for an image display device. As shown in Fig. 2, the laminate 70 for an image display device includes a wiring substrate 10, a power supply line 85 electrically connected to the wiring substrate 10, a first transparent adhesive layer (first adhesive layer) 95, and a second transparent adhesive layer (second adhesive layer) 96. Of these, the wiring substrate 10 and the power supply line 85 electrically connected to the wiring substrate 10 form a module 80A.

[0026] The wiring board 10 of the module 80A has a substrate 11, a mesh wiring section 20, and a power supply section 40. As shown in FIG. 2, the substrate 11 includes a first surface 11a and a second surface 11b located on the opposite side of the first surface 11a. The mesh wiring section 20 is disposed on the first surface 11a of the substrate 11. The power supply section 40 is electrically connected to the mesh wiring section 20. Furthermore, a communication module 63 is disposed on the negative side in the Z direction relative to the display device 61. The laminate 70 for an image display device, the display device 61, and the communication module 63 are housed in a housing 62.

[0027] 1 and 2, radio waves of a predetermined frequency can be transmitted and received via a communication module 63, enabling communication. The communication module 63 may include any of a millimeter wave antenna, a telephone antenna, a Wi-Fi antenna, a 3G antenna, a 4G antenna, a 5G antenna, an LTE antenna, a Bluetooth (registered trademark) antenna, an NFC antenna, etc. Examples of such an image display device 60 include mobile terminal devices such as smartphones and tablets.

[0028] 2, the image display device 60 has a light-emitting surface 64. The image display device 60 includes a wiring board 10 located on the light-emitting surface 64 side (positive side in the Z direction) of the display device 61, and a communication module 63 located on the opposite side of the light-emitting surface 64 of the display device 61 (negative side in the Z direction).

[0029] The display device 61 is, for example, an organic EL (Electro Luminescence) display device. The display device 61 may include, for example, a metal layer, a support substrate, a resin substrate, a thin film transistor (TFT), and an organic EL layer (not shown). A touch sensor (not shown) may be disposed on the display device 61. A wiring substrate 10 is disposed on the display device 61 via a second transparent adhesive layer 96. The display device 61 is not limited to an organic EL display device. For example, the display device 61 may be another display device that has a light-emitting function, or may be a micro LED display device including micro LED elements (light emitters). The display device 61 may also be a liquid crystal display device including liquid crystal. A cover glass (surface protection plate) 75 is disposed on the wiring substrate 10 via a first transparent adhesive layer 95. A polarizing plate (not shown) may be disposed between the first transparent adhesive layer 95 and the cover glass 75.

[0030] Next, the laminate 70 for an image display device will be described in detail. As described above, the laminate 70 for an image display device includes the wiring board 10, the power supply line 85, the first adhesive layer 95, and the second adhesive layer 96. Of these, the first transparent adhesive layer 95 is located on the first surface 11a side of the substrate 11 of the wiring board 10. The second transparent adhesive layer 96 is located on the second surface 11b side of the substrate 11 of the wiring board 10. Here, the first transparent adhesive layer 95 of the laminate 70 for an image display device will be described first. The wiring board 10 and the power supply line 85 will be described in detail later.

[0031] The first transparent adhesive layer 95 is an adhesive layer that directly or indirectly bonds the wiring substrate 10 to the decorative layer 74 and the cover glass 75 (described later). This first transparent adhesive layer 95 is located on the first surface 11a side of the substrate 11. The first transparent adhesive layer 95 is optically transparent and may be an OCA (Optical Clear Adhesive) layer. The OCA layer is a layer prepared, for example, as follows: First, a liquid curable adhesive layer composition containing a polymerizable compound is applied to a release film such as polyethylene terephthalate (PET). Next, the composition is cured using, for example, ultraviolet (UV) light to obtain an OCA sheet. After the OCA sheet is attached to an object, the release film is peeled off and removed to obtain the OCA layer. The material of the first transparent adhesive layer 95 may be an acrylic resin, a silicone resin, a urethane resin, or the like. In particular, the first transparent adhesive layer 95 may contain an acrylic resin. In this case, it is preferable that the second transparent adhesive layer 96 contains an acrylic resin. This substantially eliminates the difference in refractive index between the first transparent adhesive layer 95 and the second transparent adhesive layer 96, and more reliably suppresses reflection of visible light at the interface B3 between the first transparent adhesive layer 95 and the second transparent adhesive layer 96.

[0032] The first transparent adhesive layer 95 may have a visible light transmittance of 85% or more, preferably 90% or more. There is no particular upper limit to the visible light transmittance of the first transparent adhesive layer 95, but it may be, for example, 100% or less. By setting the visible light transmittance of the first transparent adhesive layer 95 within the above range, the transparency of the laminate 70 for an image display device can be increased, making it easier to view the display device 61 of the image display device 60. Visible light refers to light with a wavelength of 400 nm or more and 700 nm or less. A visible light transmittance of 85% or more means that, when the absorbance of the member to be measured (e.g., the first transparent adhesive layer 95) is measured, the transmittance is 85% or more over the entire wavelength range of 400 nm or more and 700 nm or less. The absorbance can be measured using a known spectrophotometer (e.g., a V-670 spectrometer manufactured by JASCO Corporation).

[0033] As described above, the wiring substrate 10 is disposed on the light-emitting surface 64 side of the display device 61. In this case, the wiring substrate 10 is located between the first transparent adhesive layer 95 and the second transparent adhesive layer 96. More specifically, a portion of the substrate 11 of the wiring substrate 10 is disposed in a portion of the region between the first transparent adhesive layer 95 and the second transparent adhesive layer 96. In this case, the first transparent adhesive layer 95, the second transparent adhesive layer 96, the display device 61, and the cover glass 75 each have a larger area than the substrate 11 of the wiring substrate 10. In this way, by disposing the substrate 11 of the wiring substrate 10 in a portion of the image display device 60 rather than over the entire surface in a plan view, the overall thickness of the image display device 60 can be reduced.

[0034] As described above, the wiring substrate 10 includes a transparent substrate 11, a mesh wiring section 20 disposed on the first surface 11a of the substrate 11, and a power supply section 40 electrically connected to the mesh wiring section 20. The power supply section 40 is electrically connected to the communication module 63 via a power supply line 85. A portion of the wiring substrate 10 is not disposed between the first transparent adhesive layer 95 and the second transparent adhesive layer 96, but protrudes outward (toward the negative Y-direction) from between the first transparent adhesive layer 95 and the second transparent adhesive layer 96. Specifically, the region of the wiring substrate 10 where the power supply section 40 is provided protrudes outward. This facilitates electrical connection between the power supply section 40 and the communication module 63. Meanwhile, the region of the wiring substrate 10 where the mesh wiring section 20 is provided is located between the first transparent adhesive layer 95 and the second transparent adhesive layer 96. Details of the wiring substrate 10 and the power supply line 85 will be described later.

[0035] The second transparent adhesive layer 96 is an adhesive layer that directly or indirectly adheres the display device 61 to the wiring substrate 10. This second transparent adhesive layer 96 is located on the second surface 11b side of the substrate 11. Like the first transparent adhesive layer 95, the second transparent adhesive layer 96 has optical transparency and may be an OCA (Optical Clear Adhesive) layer. The material of the second transparent adhesive layer 96 may be an acrylic resin, a silicone resin, a urethane resin, or the like. In particular, the second transparent adhesive layer 96 may contain an acrylic resin. This substantially eliminates the difference in refractive index between the first transparent adhesive layer 95 and the second transparent adhesive layer 96, thereby more reliably suppressing reflection of visible light at the interface B3 between the first transparent adhesive layer 95 and the second transparent adhesive layer 96.

[0036] The second transparent adhesive layer 96 may have a transmittance of 85% or more, preferably 90% or more, for visible light (light having a wavelength of 400 nm or more and 700 nm or less). There is no particular upper limit to the visible light transmittance of the second transparent adhesive layer 96, but it may be, for example, 100% or less. By setting the visible light transmittance of the second transparent adhesive layer 96 to fall within the above range, the transparency of the laminate 70 for an image display device can be increased, and the display device 61 of the image display device 60 can be made easier to view.

[0037] In this image display device 60, the difference in refractive index between the substrate 11 and the first transparent adhesive layer 95 is 0.1 or less, and preferably 0.05 or less. The difference in refractive index between the substrate 11 and the second transparent adhesive layer 96 is 0.1 or less, and preferably 0.05 or less. The difference in refractive index between the first transparent adhesive layer 95 and the second transparent adhesive layer 96 is preferably 0.1 or less, and more preferably 0.05 or less. For example, if the first transparent adhesive layer 95 and the second transparent adhesive layer 96 are made of acrylic resins with a refractive index of 1.49, the refractive index of the substrate 11 is set to 1.39 or more and 1.59 or less. Examples of such materials include fluororesins, silicone resins, polyolefin resins, polyester resins, acrylic resins, polycarbonate resins, polyimide resins, and cellulose resins.

[0038] Thus, by keeping the difference between the refractive index of the substrate 11 and the refractive index of the first transparent adhesive layer 95 to 0.1 or less, reflection of visible light at the interface B1 between the substrate 11 and the first transparent adhesive layer 95 is suppressed, making the substrate 11 less visible to the naked eye of an observer. Furthermore, by keeping the difference between the refractive index of the substrate 11 and the refractive index of the second transparent adhesive layer 96 to 0.1 or less, reflection of visible light at the interface B2 between the substrate 11 and the second transparent adhesive layer 96 is suppressed, making the substrate 11 less visible to the naked eye of an observer. Furthermore, by keeping the difference between the refractive index of the first transparent adhesive layer 95 and the refractive index of the second transparent adhesive layer 96 to 0.1 or less, reflection of visible light at the interface B3 between the first transparent adhesive layer 95 and the second transparent adhesive layer 96 is suppressed. Therefore, the first transparent adhesive layer 95 and the second transparent adhesive layer 96 are less visible to the naked eye of an observer.

[0039] In particular, it is preferable that the material of the first transparent adhesive layer 95 and the material of the second transparent adhesive layer 96 are the same. This makes it possible to further reduce the difference in refractive index between the first transparent adhesive layer 95 and the second transparent adhesive layer 96, and suppress reflection of visible light at the interface B3 between the first transparent adhesive layer 95 and the second transparent adhesive layer 96.

[0040] 2, at least one of the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 may be 1.5 times or more, preferably 2 times or more, and more preferably 2.5 times or more, the thickness T1 of the substrate 11. By making the thickness T3 of the first transparent adhesive layer 95 or the thickness T4 of the second transparent adhesive layer 96 sufficiently thicker than the thickness T1 of the substrate 11, the first transparent adhesive layer 95 or the second transparent adhesive layer 96 deforms in the thickness direction in the region overlapping with the substrate 11, absorbing the thickness of the substrate 11. This makes it possible to prevent steps from occurring in the first transparent adhesive layer 95 or the second transparent adhesive layer 96 around the periphery of the substrate 11, making it difficult for an observer to perceive the presence of the substrate 11.

[0041] At least one of the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 is preferably 10 times or less, and more preferably 5 times or less, the thickness T1 of the substrate 11. This prevents the thickness T3 of the first transparent adhesive layer 95 or the thickness T4 of the second transparent adhesive layer 96 from becoming too thick, and allows the overall thickness of the image display device 60 to be thin.

[0042] 2, the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 may be the same. In this case, the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 may each be 1.5 times or more, and preferably 2.0 times or more, the thickness T1 of the substrate 11. That is, the sum (T3 + T4) of the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 is three times or more the thickness T1 of the substrate 11. In this way, by making the sum of the thicknesses T3 and T4 of the first transparent adhesive layer 95 and the second transparent adhesive layer 96 sufficiently thicker than the thickness T1 of the substrate 11, the first transparent adhesive layer 95 and the second transparent adhesive layer 96 deform (shrink) in the thickness direction in the region overlapping with the substrate 11. As a result, the first transparent adhesive layer 95 and the second transparent adhesive layer 96 absorb the thickness of the substrate 11. This makes it possible to prevent steps from occurring in the first transparent adhesive layer 95 or the second transparent adhesive layer 96 at the periphery of the substrate 11, making it difficult for an observer to notice the presence of the substrate 11.

[0043] When the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 are the same, the thickness T3 of the first transparent adhesive layer 95 and the thickness T4 of the second transparent adhesive layer 96 may each be five times or less, and preferably three times or less, the thickness T1 of the substrate 11. This prevents the thicknesses T3 and T4 of the first transparent adhesive layer 95 and the second transparent adhesive layer 96 from becoming too thick, and allows the overall thickness of the image display device 60 to be thin.

[0044] Specifically, the thickness T1 of the substrate 11 may be, for example, 2 μm or more, 10 μm or more, and preferably 15 μm or more. By setting the thickness T1 of the substrate 11 to 2 μm or more, the strength of the wiring substrate 10 can be maintained and the first directional wiring 21 and second directional wiring 22 (described later) of the mesh wiring portion 20 can be made less likely to deform. Furthermore, the thickness T1 of the substrate 11 may be, for example, 200 μm or less, 50 μm or less, and preferably 25 μm or less. Setting the thickness T1 of the substrate 11 to 200 μm or less prevents the first transparent adhesive layer 95 and the second transparent adhesive layer 96 from forming steps at the periphery of the substrate 11, making it difficult for an observer to recognize the presence of the substrate 11. Setting the thickness T1 of the substrate 11 to 50 μm or less further prevents the first transparent adhesive layer 95 and the second transparent adhesive layer 96 from forming steps at the periphery of the substrate 11, making it even more difficult for an observer to recognize the presence of the substrate 11.

[0045] The thickness T3 of the first transparent adhesive layer 95 may be, for example, 15 μm or more, and preferably 20 μm or more. The thickness T3 of the first transparent adhesive layer 95 may be, for example, 500 μm or less, and preferably 300 μm or less, and more preferably 250 μm or less. The thickness T4 of the second transparent adhesive layer 96 may be, for example, 15 μm or more, and preferably 20 μm or more. The thickness T4 of the second transparent adhesive layer 96 may be, for example, 500 μm or less, and preferably 300 μm or less, and more preferably 250 μm or less.

[0046] Referring again to FIG. 2 , the cover glass 75 is disposed directly or indirectly on the first transparent adhesive layer 95. The cover glass 75 is located on the positive side of the first transparent adhesive layer 95 in the Z direction. The cover glass 75 is a light-transmitting glass member. The cover glass 75 is plate-shaped and may have a rectangular shape in a plan view. The thickness of the cover glass 75 may be, for example, 200 μm to 1000 μm, and preferably 300 μm to 700 μm. The length of the cover glass 75 in the longitudinal direction (Y direction) may be, for example, 20 mm to 500 mm, and preferably 100 mm to 200 mm. The length of the cover glass 75 in the lateral direction (X direction) may be 20 mm to 500 mm, and preferably 50 mm to 100 mm. A decorative layer 74 is provided between the cover glass 75 and the first transparent adhesive layer 95.

[0047] At least a portion of the decorative layer 74 is disposed on the first transparent adhesive layer 95. The decorative layer 74 may be a decorative film. For example, the decorative layer 74 has an opening in all or part of the portion that overlaps with the display area of ​​the display device 61 when viewed from the viewer's side, and blocks light from the portions other than the display area. In other words, the decorative layer 74 is disposed so as to cover the edge of the display device 61 when viewed from the viewer's side.

[0048] As shown in FIG. 1, the shape of the image display device 60 is generally rectangular in plan view, with its longitudinal direction parallel to the Y direction and its lateral direction parallel to the X direction. The length L4 of the image display device 60 in the longitudinal direction (Y direction) can be selected, for example, from 20 mm to 500 mm, preferably from 100 mm to 200 mm. The length L5 of the image display device 60 in the lateral direction (X direction) can be selected, for example, from 20 mm to 500 mm, preferably from 50 mm to 100 mm. The planar shape of the image display device 60 may also be a rectangle with rounded corners.

[0049] Next, the configuration of the wiring board will be described with reference to Figures 3 to 6. Figures 3 to 6 are diagrams showing the wiring board according to this embodiment.

[0050] The wiring board 10 according to the present embodiment is a board used in the image display device 60 described above (see FIGS. 1 and 2). The wiring board 10 can be disposed on the light-emitting surface 64 side of the display device 61, between a first transparent adhesive layer 95 and a second transparent adhesive layer 96. As shown in FIG. 3, such a wiring board 10 includes a transparent substrate 11, a plurality of mesh wiring sections 20 disposed on the substrate 11, and a power supply section 40, as described above. The mesh wiring section 20 is electrically connected to the power supply section 40.

[0051] The shape of the substrate 11 is approximately rectangular in a plan view. The substrate 11 is transparent and approximately flat, and its thickness is approximately uniform overall. The length L1 (see Figures 1 and 3) of the substrate 11 in the longitudinal direction (Y direction) of the image display device 60 can be selected, for example, from 10 mm to 200 mm. The length L2 (see Figure 1) of the substrate 11 in the lateral direction (X direction) of the image display device 60 can be selected, for example, from 3 mm to 100 mm. The planar shape of the substrate 11 may be a rectangle with rounded corners.

[0052] The material of the substrate 11 may be any material that is transparent in the visible light range and electrically insulating. The material of the substrate 11 is preferably an organic insulating material such as a polyester resin, an acrylic resin, a polycarbonate resin, a polyimide resin, a polyolefin resin, a cellulose resin, or a fluororesin material. The polyester resin may be polyethylene terephthalate or the like. The acrylic resin may be polymethyl methacrylate or the like. The polyolefin resin may be a cycloolefin polymer or the like. The cellulose resin may be triacetyl cellulose or the like. The fluororesin material may be PTFE or PFA or the like. For example, the material of the substrate 11 may be an organic insulating material such as a cycloolefin polymer (e.g., ZF-16 manufactured by Nippon Zeon Co., Ltd.) or a polynorbornene polymer (manufactured by Sumitomo Bakelite Co., Ltd.). Furthermore, the material of the substrate 11 may be glass, ceramics, or the like, appropriately selected depending on the application. Although the substrate 11 is illustrated as being made up of a single layer, the present invention is not limited to this and may have a structure in which multiple base materials or layers are laminated. Furthermore, the substrate 11 may be a film-like member or a plate-like member.

[0053] The dielectric loss tangent of substrate 11 is preferably 0.002 or less. When the dielectric loss tangent of substrate 11 is in the above range, it is possible to reduce the gain loss (reduction in sensitivity) associated with the transmission and reception of electromagnetic waves, particularly when the electromagnetic waves (e.g., millimeter waves) transmitted and received by mesh wiring portion 20 are high frequency.

[0054] The relative dielectric constant of the substrate 11 is preferably 2 or more and 10 or less. When the relative dielectric constant of the substrate 11 is 2 or more, the options for materials for the substrate 11 are increased. Furthermore, when the relative dielectric constant of the substrate 11 is 10 or less, the gain loss associated with the transmission and reception of electromagnetic waves can be reduced. That is, when the relative dielectric constant of the substrate 11 is large, the influence of the thickness of the substrate 11 on the propagation of electromagnetic waves increases. Furthermore, when there is an adverse effect on the propagation of electromagnetic waves, the dielectric loss tangent of the substrate 11 increases, which can increase the gain loss associated with the transmission and reception of electromagnetic waves. In contrast, when the relative dielectric constant of the substrate 11 is 10 or less, the influence of the thickness of the substrate 11 on the propagation of electromagnetic waves can be reduced. Therefore, the gain loss associated with the transmission and reception of electromagnetic waves can be reduced. In particular, when the electromagnetic waves (e.g., millimeter waves) transmitted and received by the mesh wiring unit 20 are high frequency, the gain loss associated with the transmission and reception of electromagnetic waves can be reduced.

[0055] The dielectric loss tangent and relative dielectric constant of the substrate 11 can be measured in accordance with IEC 62562. Specifically, first, a test piece is prepared by cutting out a portion of the substrate 11 where the mesh wiring portion 20 is not formed. The dimensions of the test piece are a width of 10 mm to 20 mm and a length of 50 mm to 100 mm. Next, the dielectric loss tangent or relative dielectric constant is measured in accordance with IEC 62562.

[0056] In this embodiment, substrate 11 is transparent. In this specification, "transparent" means that the transmittance of visible light (light having a wavelength of 400 nm or more and 700 nm or less) is 85% or more. Substrate 11 may have a visible light transmittance of 85% or more, and preferably 90% or more. There is no particular upper limit to the visible light transmittance of substrate 11, but it may be, for example, 100% or less. By setting the visible light transmittance of substrate 11 to be within the above range, the transparency of wiring board 10 can be increased, and display device 61 of image display device 60 can be more easily viewed.

[0057] In this embodiment, the mesh wiring section 20 is made up of an antenna pattern that functions as an antenna. This mesh wiring section 20 may be configured as an array antenna. When the mesh wiring section 20 is configured as an array antenna in this way, it is possible to improve the performance of the millimeter wave antenna that transmits and receives millimeter waves with high linearity. Note that an array antenna is an antenna in which multiple antenna elements (radiating elements) are regularly arranged, and in which the amplitude and phase of the excitation of the elements can be controlled independently.

[0058] As shown in FIG. 3, a plurality of mesh wiring portions 20 are formed on the substrate 11. It is preferable that four or more mesh wiring portions 20 are provided. In the illustrated example, four mesh wiring portions 20 are formed on the substrate 11 (see FIG. 1). Also, as shown in FIG. 3, the mesh wiring portions 20 may not be present over the entire surface of the substrate 11, but may be present only in a partial region on the substrate 11. Each mesh wiring portion 20 may have the same shape. In this case, each mesh wiring portion 20 has a length (distance in the Y direction) L of a tip side portion 20b described later. a Error and width (X direction distance) W a It is preferable that the error of each of these is within 10%, which can effectively improve the performance of the millimeter wave antenna.

[0059] The mesh wiring unit 20 has a base end portion (power transmission unit) 20a on the power supply unit 40 side and a tip end portion (transmitter / receiver) 20b connected to the base end portion 20a. The base end portion 20a is connected to the power supply unit 40. In this case, the base end portion (power transmission unit) 20a may be configured as a microstrip line or a coplanar line. The base end portion 20a and the tip end portion 20b each have a substantially rectangular shape in a plan view. In this case, the length (distance in the Y direction) of the tip end portion 20b is substantially the same as the length (distance in the Y direction) of the base end portion 20a, and the width (distance in the X direction) of the tip end portion 20b is wider than the width (distance in the X direction) of the base end portion 20a.

[0060] The tip end portion 20b of the mesh wiring portion 20 corresponds to a predetermined frequency band. That is, the tip end portion 20b has a length (distance in the Y direction) L a The length L of the tip portion 20b corresponds to a specific frequency band. a The mesh wiring section 20 may be a millimeter-wave antenna, or may be compatible with any of a telephone antenna, a WiFi antenna, a 3G antenna, a 4G antenna, a 5G antenna, an LTE antenna, a Bluetooth (registered trademark) antenna, an NFC antenna, etc. The lengths of the plurality of tip portions 20b may be different from each other, and each may correspond to a different frequency band. Alternatively, if the wiring board 10 does not have a radio wave transmission / reception function, each mesh wiring section 20 may perform functions such as a hovering function, fingerprint authentication, a heater, noise reduction (shielding), etc. The hovering function refers to a function that allows the user to operate the display without directly touching it.

[0061] The length L of the tip portion 20b in the Y direction is equal to the length L of the tip portion 20b in the X direction. a The width W of the tip portion 20b in the X direction can be selected, for example, in the range of 1 mm to 100 mm. a In particular, when the mesh wiring portion 20 is a millimeter wave antenna, the length L of the tip side portion 20b can be selected within a range of, for example, 1 mm or more and 100 mm or less. a When the mesh wiring portion 20 is a millimeter wave antenna, the length L of the tip side portion 20b can be selected from the range of 1 mm or more, more preferably 1.5 mm or more. a can be selected in the range of 10 mm or less, more preferably 5 mm or less.

[0062] The distance between the mesh wiring portions 20 is preferably 1 mm or more and 5 mm or less. 20b The distance D between the tip end portions 20b (see FIG. 3) is preferably 1 mm or more and 5 mm or less. 20bBy making the distance D between the tip side portions 20b equal to or greater than 1 mm, unintended interference of electromagnetic waves between the antenna elements can be suppressed. 20b By making the distance D between the tip side portions 20b 5 mm or less, it is possible to reduce the size of the entire array antenna formed by the mesh wiring portion 20. For example, when the mesh wiring portion 20 is a millimeter wave antenna of 28 GHz, the distance D between the tip side portions 20b 20b In addition, when the mesh wiring portion 20 is a millimeter wave antenna of 60 GHz, the distance D between the tip side portions 20b may be 3.5 mm. 20b may be 1.6 mm.

[0063] 4, the mesh wiring section 20 has a pattern shape in which metal wires are arranged in a lattice or mesh shape. This pattern shape is repeatedly arranged in the X direction and the Y direction. That is, the mesh wiring section 20 has a pattern shape consisting of a portion (first-directional wiring 21 described later) extending in a first direction (e.g., Y direction) and a portion (second-directional wiring 22 described later) extending in a second direction (e.g., X direction).

[0064] The mesh wiring section 20 has a plurality of wires. Specifically, the mesh wiring section 20 has a plurality of first-directional wires 21 and a plurality of second-directional wires 22 connecting the plurality of first-directional wires 21. The plurality of first-directional wires 21 and the plurality of second-directional wires 22 are integrated as a whole to form a lattice or mesh shape. Each of the first-directional wires 21 extends in the longitudinal direction (Y direction) of the mesh wiring section 20. Each of the second-directional wires extends linearly in the width direction (X direction) of the mesh wiring section 20. Note that the first-directional wires 21 and the second-directional wires 22 may extend in a direction that is not parallel to either the X direction or the Y direction.

[0065] In the mesh wiring portion 20, a plurality of openings 23 are formed by being surrounded by adjacent first-directional wires 21 and adjacent second-directional wires 22. The planar shape of each opening 23 is approximately square in plan view. The transparent substrate 11 is exposed from each opening 23. This can increase the transparency of the wiring substrate 10 as a whole.

[0066] In the mesh wiring section 20, a plurality of openings 23 are formed by being surrounded by adjacent first-directional wirings 21 and adjacent second-directional wirings 22. The first-directional wirings 21 and the second-directional wirings 22 are arranged at equal intervals. That is, the plurality of first-directional wirings 21 are arranged at equal intervals, and the pitch P1 can be, for example, in the range of 0.01 mm to 1 mm. The plurality of second-directional wirings 22 are arranged at equal intervals, and the pitch P2 can be, for example, in the range of 0.01 mm to 1 mm. Since the plurality of first-directional wirings 21 and the plurality of second-directional wirings 22 are arranged at equal intervals, the size of the openings 23 within the mesh wiring section 20 is uniform, making the mesh wiring section 20 difficult to see with the naked eye. The pitch P1 of the first-directional wirings 21 is equal to the pitch P2 of the second-directional wirings 22. Therefore, each opening 23 has a substantially square shape in a plan view, and the transparent substrate 11 is exposed through each opening 23. Therefore, by increasing the area of ​​each opening 23, the transparency of the wiring substrate 10 as a whole can be increased. The length L3 of one side of each opening 23 can be set, for example, in the range of 0.01 mm to 1 mm. The first directional wirings 21 and the second directional wirings 22 are orthogonal to each other, but this is not limited thereto and they may intersect at an acute or obtuse angle. Furthermore, the shape of the openings 23 is preferably the same shape and size over the entire surface, but it does not have to be uniform over the entire surface, and may vary depending on the location.

[0067] As shown in FIG. 5, each of the first-directional wirings 21 has a cross section perpendicular to its longitudinal direction (X-direction cross section) that is substantially rectangular or square. In this case, the cross-sectional shape of the first-directional wirings 21 is substantially uniform along the longitudinal direction (Y-direction) of the first-directional wirings 21. As shown in FIG. 6, each of the second-directional wirings 22 has a cross section perpendicular to its longitudinal direction (Y-direction cross section) that is substantially rectangular or square, and has substantially the same shape as the cross-sectional shape (X-direction cross section) of the first-directional wirings 21 described above. In this case, the cross-sectional shape of the second-directional wirings 22 is substantially uniform along the longitudinal direction (X-direction) of the second-directional wirings 22. The cross-sectional shapes of the first-directional wirings 21 and the second-directional wirings 22 do not necessarily have to be substantially rectangular or square. For example, the cross-sectional shape of the first direction wiring 21 and the cross-sectional shape of the second direction wiring 22 may be an approximately trapezoid with the front side (positive side in the Z direction) narrower than the back side (negative side in the Z direction), or a shape with curved side surfaces located on both sides in the longitudinal direction.

[0068] In this embodiment, the line width W1 of the first-directional wiring 21 (see FIG. 5) and the line width W2 of the second-directional wiring 22 (see FIG. 6) are not particularly limited and can be appropriately selected depending on the application. Here, the line width W1 of the first-directional wiring 21 is the width (distance in the X direction) in a cross section perpendicular to its longitudinal direction, and the line width W2 of the second-directional wiring 22 is the width (distance in the Y direction) in a cross section perpendicular to its longitudinal direction. For example, the line width W1 of the first-directional wiring 21 can be selected from a range of 0.1 μm to 5.0 μm, and preferably from 0.2 μm to 2.0 μm. Furthermore, the line width W2 of the second-directional wiring 22 can be selected from a range of 0.1 μm to 5.0 μm, and preferably from 0.2 μm to 2.0 μm.

[0069] The height H1 of the first directional wiring 21 (see FIG. 5) and the height H2 of the second directional wiring 22 (see FIG. 6) are not particularly limited and can be appropriately selected depending on the application. Here, the height H1 of the first directional wiring 21 and the height H2 of the second directional wiring 22 are each lengths in the Z direction. The height H1 of the first directional wiring 21 and the height H2 of the second directional wiring 22 can each be selected, for example, within a range of 0.1 μm or more, and preferably 0.2 μm or more. The height H1 of the first directional wiring 21 and the height H2 of the second directional wiring 22 can each be selected, for example, within a range of 5.0 μm or less, and preferably 2.0 μm or less.

[0070] The material of the first directional wiring 21 and the second directional wiring 22 may be any metal material having electrical conductivity. In the present embodiment, the material of the first directional wiring 21 and the second directional wiring 22 is copper, but is not limited to this. The material of the first directional wiring 21 and the second directional wiring 22 may be, for example, a metal material such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel, or an alloy containing these metals. Furthermore, the first directional wiring 21 and the second directional wiring 22 may be a plating layer formed by electrolytic plating.

[0071] The overall aperture ratio At of the mesh wiring portion 20 may be, for example, in the range of 87% or more and less than 100%. By setting the overall aperture ratio At of the mesh wiring portion 20 in this range, the conductivity and transparency of the wiring substrate 10 can be ensured. The overall aperture ratio At of the mesh wiring portion 20 is preferably 95% or more and less than 100%. This allows the transparency of the wiring substrate 10 to be increased while ensuring the conductivity of the wiring substrate 10. The aperture ratio refers to the ratio (%) of the area of ​​the open region to the unit area of ​​a predetermined region (for example, the entire region of the mesh wiring portion 20). The open region refers to a region where no metal parts such as the first directional wiring 21 and the second directional wiring 22 are present and the substrate 11 is exposed.

[0072] Although not shown, a protective layer may be formed on the first surface 11a of the substrate 11 so as to cover the mesh wiring portion 20. The protective layer protects the mesh wiring portion 20 and is formed so as to cover at least the mesh wiring portion 20 of the substrate 11. Examples of materials that can be used for the protective layer include colorless and transparent insulating resins such as acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate, modified resins thereof, copolymers thereof, polyester, polyvinyl alcohol, polyvinyl acetate, polyvinyl acetal, and polyvinyl butyral, copolymers thereof, polyurethane, epoxy resin, polyamide, and chlorinated polyolefin.

[0073] 3, power supply unit 40 is electrically connected to mesh wiring unit 20. Power supply unit 40 is made of a substantially rectangular conductive thin plate member. The longitudinal direction of power supply unit 40 is parallel to the X direction, and the lateral direction of power supply unit 40 is parallel to the Y direction.

[0074] Furthermore, power supply unit 40 is disposed at the longitudinal end (the end on the negative Y-direction side) of substrate 11. The material of power supply unit 40 may be, for example, a metal material such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel, or an alloy containing these metals.

[0075] When wiring board 10 is incorporated into image display device 60 (see FIGS. 1 and 2), power supply unit 40 is electrically connected to communication module 63 of image display device 60 via power supply line 85. Note that power supply unit 40 is provided on first surface 11a of substrate 11, but this is not limiting, and part or all of power supply unit 40 may be located outside the periphery of substrate 11. Furthermore, power supply unit 40 may be configured to be flexible so that it can wrap around the side or back surface of image display device 60. In this case, power supply unit 40 may be electrically connected to communication module 63 on the side or back surface of image display device 60.

[0076] The mesh wiring section 20 is electrically connected to the power supply section 40 on the positive side in the Y direction. In this case, the power supply section 40 is formed integrally with the mesh wiring section 20. The thickness T5 (Z direction distance, see FIG. 6) of the power supply section 40 can be set to be the same as the height H1 (see FIG. 5) of the first direction wirings 21 and the height H2 (see FIG. 6) of the second direction wirings 22, and can be selected, for example, in the range of 0.1 μm to 5.0 μm. In addition, an oxide film (first oxide film) 40a is formed on the surface of the power supply section 40.

[0077] Next, the configuration of the module will be described with reference to Fig. 7. Fig. 7 is a diagram showing the module according to this embodiment.

[0078] 7, module 80A includes the above-described wiring board 10 and power supply line 85 electrically connected to power supply unit 40 via anisotropic conductive film 85c. As described above, when module 80A is incorporated into image display device 60 having display device 61, power supply unit 40 of wiring board 10 is electrically connected to communication module 63 of image display device 60 via power supply line 85.

[0079] The power supply line 85 is pressure-bonded to the wiring board 10 via an anisotropic conductive film (ACF) 85c. The anisotropic conductive film 85c contains a resin material such as acrylic resin or epoxy resin, and a plurality of conductive particles 85d. In the illustrated example, the anisotropic conductive film 85c covers a portion of the power supply unit 40. This can prevent corrosion of the power supply unit 40.

[0080] The anisotropic conductive film 85c is disposed so as to face the power supply unit 40. A portion of each conductive particle 85d is in contact with the power supply unit 40. This electrically connects the power supply line 85 to the power supply unit 40. Note that a portion of the anisotropic conductive film 85c may be dissolved around the power supply line 85 when the power supply line 85 is pressure-bonded to the wiring board 10.

[0081] The thickness T7 (see FIG. 7) of the anisotropic conductive film 85c may be 3 μm or more and 20 μm or less. When the thickness T7 of the anisotropic conductive film 85c is 3 μm or more, the adhesion between the power supply section 40 and the power supply line 85 can be improved. Furthermore, when the thickness T7 of the anisotropic conductive film 85c is 20 μm or less, the thickness of the image display device 60 can be reduced.

[0082] The conductive particles 85d have an average particle diameter of 3 μm or more and 20 μm or less. When the conductive particles 85d have an average particle diameter of 3 μm or more, the conductive particles 85d are more likely to come into contact with the power supply section 40 and the metal wiring section 85b (described later) of the power supply line 85. This makes it possible to suppress a decrease in electrical connectivity. Furthermore, when the conductive particles 85d have an average particle diameter of 20 μm or less, the thickness T7 of the anisotropic conductive film 85c does not become too large, and the overall thickness of the module 80A and the image display device 60 can be reduced.

[0083] When measuring the average particle diameter of the conductive particles 85d, first, the power supply line 85 is peeled off from the power supply section 40 to expose the plurality of conductive particles 85d from the resin material of the anisotropic conductive film 85c. Next, the exposed plurality of conductive particles 85d are photographed using a scanning electron microscope (SEM). Next, the particle diameters of the plurality of conductive particles 85d are measured from the obtained image. If the shape of the conductive particles 85d is distorted, the diameters of the plurality of conductive particles 85d are measured at multiple points on each target conductive particle 85d and an average value is calculated. The average value of the measured values ​​of the plurality of conductive particles 85d is then used as the average particle diameter of the conductive particles 85d. The number of conductive particles 85d to be measured is 10 to 100. Note that if the number of measurable conductive particles 85d in one power supply line 85 is 9 or less, the average particle diameter of the conductive particles 85d is calculated using the particle diameters of the conductive particles 85d in the other power supply lines 85. Furthermore, if the conductive particles 85d are not exposed from the resin material of the anisotropic conductive film 85c, a scanning electron microscope is used to photograph the shapes of the conductive particles 85d inside the resin material of the anisotropic conductive film 85c.

[0084] Furthermore, among the plurality of conductive particles 85d whose particle diameters have been measured, 20% of the total conductive particles 85d in ascending order of particle diameter and 20% of the total conductive particles 85d in descending order of particle diameter are excluded, and for the remaining 60% of the conductive particles 85d, the value obtained by subtracting the maximum from the minimum particle diameter is preferably 60% or less of the average particle diameter. For example, if the number of conductive particles 85d whose particle diameters have been measured is 100, the value obtained by subtracting the maximum from the minimum particle diameter of the remaining 60 conductive particles 85d in descending order of particle diameter are preferably 60% or less of the average particle diameter. In other words, if the number of conductive particles 85d whose particle diameters have been measured is 100, the value obtained by subtracting the diameter of the 80th largest particle from the diameter of the 21st largest particle is preferably 60% or less of the average particle diameter. This reduces variations in the density of the conductive particles 85d in the resin material of the anisotropic conductive film 85c, thereby stabilizing the antenna characteristics of the wiring board 10.

[0085] The conductive particles 85d penetrate the oxide film 40a of the power supply portion 40. This makes it possible to effectively prevent the electrical connectivity between the power supply line 85 and the power supply portion 40 from deteriorating.

[0086] Furthermore, the conductive particles 85d penetrate an oxide film 85e (described later) of the power supply line 85. In this case as well, the deterioration of the electrical connectivity with the power supply line 85 can be effectively suppressed.

[0087] The power supply line 85 may be, for example, a flexible printed circuit board. The power supply line 85 has a base material 85a and a metal wiring portion 85b laminated on the base material 85a. Of these, the base material 85a may contain, for example, a resin material such as polyimide or a liquid crystal polymer. The metal wiring portion 85b may contain, for example, copper. The metal wiring portion 85b is arranged to face the power supply unit 40. In addition, an oxide film (second oxide film) 85e is formed on the surface of the metal wiring portion 85b. This metal wiring portion 85b is electrically connected to the power supply unit 40 via conductive particles 85d.

[0088] As shown in FIG. 2 , the power supply unit 40 and the power supply line 85 of the wiring board 10 are joined to each other via a joint 88. The length L7 of the joint 88 is preferably 0.3 mm or more and 20 mm or less. Having the length L7 of the joint 88 be 0.3 mm or more improves the adhesion between the power supply unit 40 and the power supply line 85. Having the length L7 of the joint 88 be 20 mm or less prevents the power supply line 85 from extending beyond the display area of ​​the display device 61, thereby increasing the display area of ​​the display device 61. Having the length L7 of the joint 88 be 20 mm or less prevents the power supply line 85 from coming too close to the housing 62, thereby preventing a large load from being applied to the power supply line 85 due to bending of the power supply line 85. This reduces power loss in the power supply line 85.

[0089] [Method of manufacturing a wiring board, a module, and a laminate for an image display device] Next, with reference to Figures 8(a)-(f), Figures 9(a)-(c), and Figures 10(a)-(c), a method for manufacturing the wiring substrate 10, a method for manufacturing the module 80A, and a method for manufacturing the laminate 70 for an image display device according to this embodiment will be described. Figures 8(a)-(f) are cross-sectional views showing a method for manufacturing the wiring substrate 10 according to this embodiment. Figures 9(a)-(c) are cross-sectional views showing a method for manufacturing the module 80A according to this embodiment. Figures 10(a)-(c) are cross-sectional views showing a method for manufacturing the laminate 70 for an image display device according to this embodiment.

[0090] First, with reference to FIGS. 8(a) to 8(f), a method for manufacturing a wiring board according to this embodiment will be described.

[0091] 8(a), a substrate 11 is prepared, which includes a first surface 11a and a second surface 11b located on the opposite side of the first surface 11a. The substrate 11 is transparent.

[0092] Next, on the first surface 11a of the substrate 11, the mesh wiring section 20 and the power supply section 40 electrically connected to the mesh wiring section 20 are formed.

[0093] 8(b), first, metal foil 51 is laminated over substantially the entire first surface 11a of substrate 11. In this embodiment, the thickness of metal foil 51 may be 0.1 μm or more and 5.0 μm or less. In this embodiment, metal foil 51 may contain copper.

[0094] 8(c), a photo-curable insulating resist 52 is applied to almost the entire surface of the metal foil 51. Examples of the photo-curable insulating resist 52 include organic resins such as acrylic resins and epoxy resins.

[0095] 8(d), the insulating layer 54 is formed by photolithography. In this case, the photo-curable insulating resist 52 is patterned by photolithography to form the insulating layer 54 (resist pattern). At this time, the insulating layer 54 is formed so that the metal foil 51 corresponding to the first-directional wiring 21 and the second-directional wiring 22 is exposed.

[0096] 8(e), the metal foil 51 located on the first surface 11a of the substrate 11 in the portion not covered with the insulating layer 54 is removed. At this time, the metal foil 51 is etched so as to expose the first surface 11a of the substrate 11 by wet treatment using ferric chloride, cupric chloride, a strong acid such as sulfuric acid or hydrochloric acid, persulfate, hydrogen peroxide, an aqueous solution of these, or a combination of these.

[0097] 8(f), the insulating layer 54 is removed by wet treatment using a permanganate solution, N-methyl-2-pyrrolidone, an acid or alkaline solution, or dry treatment using oxygen plasma.

[0098] In this manner, a wiring board 10 is obtained that includes the substrate 11 and the mesh wiring portion 20 provided on the first surface 11a of the substrate 11. In this case, the mesh wiring portion 20 includes first-directional wiring 21 and second-directional wiring 22. At this time, the power supply portion 40 may be formed by a part of the metal foil. Alternatively, a flat-plate-shaped power supply portion 40 may be separately prepared and electrically connected to the mesh wiring portion 20.

[0099] Next, a method for manufacturing the module according to this embodiment will be described with reference to FIGS.

[0100] First, as shown in Fig. 9(a), the wiring board 10 is prepared. At this time, the wiring board 10 is fabricated, for example, by the method shown in Figs. 8(a) to 8(f).

[0101] Next, the power supply line 85 is electrically connected to the power supply unit 40 via an anisotropic conductive film 85c containing a plurality of conductive particles 85d. At this time, first, the anisotropic conductive film 85c and the power supply line 85 are placed on the wiring board 10, as shown in FIG. 9(b). At this time, the anisotropic conductive film 85c is placed so as to face the power supply unit 40.

[0102] Next, as shown in FIG. 9( c), the power supply line 85 is pressure-bonded to the wiring board 10. At this time, pressure and heat are applied to the power supply line 85, thereby pressure-bonding the power supply line 85 to the wiring board 10. Then, the conductive particles 85d come into contact with the power supply portion 40. At this time, the conductive particles 85d break through the oxide film 40a. The conductive particles 85d also come into contact with the metal wiring portion 85b of the power supply line 85. At this time, the conductive particles 85d break through the oxide film 85e. In this manner, the power supply portion 40 and the power supply line 85 are joined to each other via the joint portion 88, and the power supply line 85 is electrically connected to the power supply portion 40. When pressure-bonding the power supply line 85 to the wiring board 10, the power supply line 85 is pressure-bonded to the wiring board 10 so that the anisotropic conductive film 85c covers at least a portion of the power supply portion 40. At this time, a part of the anisotropic conductive film 85c may be dissolved around the power supply line 85.

[0103] In this way, module 80A is obtained, which includes wiring substrate 10 and power supply line 85 electrically connected to power supply section 40 via anisotropic conductive film 85c containing conductive particles 85d.

[0104] Next, a method for manufacturing the image display device 60 according to this embodiment will be described with reference to FIGS.

[0105] Next, the first transparent adhesive layer 95, the wiring substrate 10 of the module 80A, and the second transparent adhesive layer 96 are laminated together. First, as shown in FIG. 10(a), an OCA sheet 90 is prepared, which includes, for example, a polyethylene terephthalate (PET) release film 91 and an OCA layer 92 (the first transparent adhesive layer 95 or the second transparent adhesive layer 96) laminated on the release film 91. The OCA layer 92 may be formed by applying a liquid curable adhesive layer composition containing a polymerizable compound onto the release film 91 and curing the composition using, for example, ultraviolet (UV) light. This curable adhesive layer composition contains a polar group-containing monomer.

[0106] 10(b), the OCA layer 92 of the OCA sheet 90 is attached to the wiring board 10. As a result, the wiring board 10 is sandwiched between the OCA layers 92.

[0107] Next, as shown in Figure 10(c), the release film 91 is peeled off and removed from the OCA layer 92 of the OCA sheet 90 attached to the wiring board 10, thereby obtaining a first transparent adhesive layer 95 (OCA layer 92), the wiring board 10 and a second transparent adhesive layer 96 (OCA layer 92) laminated together.

[0108] Thereafter, a decorative film as the decorative layer 74 and a cover glass 75 are laminated on the first transparent adhesive layer 95 .

[0109] In this manner, a laminate 70 for an image display device is obtained, which includes the first transparent adhesive layer 95, the second transparent adhesive layer 96, and the module 80A including the wiring substrate 10.

[0110] Then, by laminating a display device 61 on the laminate 70 for an image display device, an image display device 60 is obtained, which comprises the laminate 70 for an image display device and the display device 61 laminated on the laminate 70 for an image display device.

[0111] [Operation of this embodiment] Next, the operation of this embodiment having the above configuration will be described.

[0112] 1 and 2, the wiring board 10 is incorporated into an image display device 60 having a display device 61. At this time, the wiring board 10 is placed on the display device 61. The mesh wiring section 20 of the wiring board 10 is electrically connected to the communication module 63 of the image display device 60 via the power supply section 40 and the power supply line 85. In this way, radio waves of a predetermined frequency can be transmitted and received via the mesh wiring section 20, and communication can be performed using the image display device 60.

[0113] According to the present embodiment, the power supply line 85 is electrically connected to the power supply unit 40 via an anisotropic conductive film 85c containing a plurality of conductive particles 85d. The conductive particles 85d have an average particle diameter of 3 μm or more and 20 μm or less. Since the average particle diameter of the conductive particles 85d is 3 μm or more, the conductive particles 85d are more likely to come into contact with the power supply unit 40 and the metal wiring portion 85b. This makes it possible to suppress a decrease in electrical connectivity. Furthermore, since the average particle diameter of the conductive particles 85d is 20 μm or less, the thickness T7 of the anisotropic conductive film 85c does not become too large, and the overall thickness of the module 80A and the image display device 60 can be reduced.

[0114] Furthermore, according to this embodiment, wiring board 10 includes substrate 11 and mesh wiring section 20 disposed on substrate 11. Substrate 11 is transparent. Mesh wiring section 20 has a conductor section as a forming section of an opaque conductive layer and a mesh pattern with numerous openings. This ensures the transparency of wiring board 10. As a result, when wiring board 10 is placed on display device 61, display device 61 can be seen through openings 23 of mesh wiring section 20, and visibility of display device 61 is not obstructed.

[0115] Furthermore, according to the present embodiment, the conductive particles 85d penetrate the oxide film 40a of the power supply portion 40. This makes it possible to effectively prevent a decrease in the electrical connectivity between the power supply line 85 and the power supply portion 40.

[0116] Furthermore, according to this embodiment, the conductive particles 85d penetrate an oxide film 85e (described later) of the power supply line 85. In this case as well, it is possible to effectively prevent a decrease in electrical connectivity with the power supply line 85.

[0117] Next, modified examples of the wiring board will be described.

[0118] Figures 11 and 12 show a first modified example of the wiring board. The modified example shown in Figures 11 and 12 differs in that a dummy wiring section 30 is provided around the mesh wiring section 20, but other configurations are substantially the same as the embodiment shown in Figures 1 to 10 described above. In Figures 11 and 12, the same parts as those shown in Figures 1 to 10 are given the same reference numerals and detailed description thereof will be omitted.

[0119] 11, a dummy wiring section 30 is provided along the periphery of the mesh wiring section 20. Unlike the mesh wiring section 20, this dummy wiring section 30 does not actually function as an antenna.

[0120] As shown in FIG. 12, the dummy wiring section 30 is composed of repeated dummy wirings 30a having a predetermined pattern shape. That is, the dummy wiring section 30 includes a plurality of dummy wirings 30a, and each dummy wiring 30a is electrically independent from the mesh wiring section 20 (the first-directional wirings 21 and the second-directional wirings 22). The plurality of dummy wirings 30a are regularly arranged throughout the dummy wiring section 30. The plurality of dummy wirings 30a are spaced apart from each other in the planar direction and are arranged to protrude above the substrate 11. That is, each dummy wiring 30a is electrically independent from the mesh wiring section 20, the power supply section 40, and other dummy wirings 30a. The shape of each dummy wiring 30a is approximately L-shaped in plan view.

[0121] In this case, the dummy wiring 30a has a shape in which a portion of the pattern shape of the mesh wiring portion 20 described above is missing. This makes it difficult to visually recognize the difference between the mesh wiring portion 20 and the dummy wiring portion 30, and makes the mesh wiring portion 20 arranged on the substrate 11 less visible. As shown in FIG. 12 , the dummy wiring 30a extends parallel to the first directional wiring 21 or the second directional wiring 22. Specifically, the dummy wiring 30a includes a first portion 31a extending parallel to the first directional wiring 21 and a second portion 32a extending parallel to the second directional wiring 22. In this way, the dummy wiring 30a extending parallel to the first directional wiring 21 or the second directional wiring 22 makes the mesh wiring portion 20 arranged on the substrate 11 even less visible. The aperture ratio of the dummy wiring portion 30 may be the same as or different from the aperture ratio of the mesh wiring portion 20, but is preferably close to the aperture ratio of the mesh wiring portion 20.

[0122] As in this modification, the dummy wiring section 30 that is electrically independent from the mesh wiring section 20 is provided around the mesh wiring section 20, thereby making the outer edge of the mesh wiring section 20 unclear. This makes it possible to make the mesh wiring section 20 less visible on the surface of the image display device 60, and makes it difficult for a user of the image display device 60 to recognize the mesh wiring section 20 with the naked eye.

[0123] Figures 13 and 14 show a second modified example of the wiring board. The modified example shown in Figures 13 and 14 differs in that a plurality of dummy wiring sections 30A, 30B having different aperture ratios are provided around the mesh wiring section 20, but other configurations are substantially the same as the embodiment shown in Figures 1 to 12 described above. In Figures 13 and 14, the same parts as those shown in Figures 1 to 12 are given the same reference numerals and detailed description thereof will be omitted.

[0124] 13, a plurality of (two in this case) dummy wiring sections 30A, 30B (first dummy wiring section 30A and second dummy wiring section 30B) having different aperture ratios are provided along the periphery of mesh wiring section 20. Specifically, first dummy wiring section 30A is arranged along the periphery of mesh wiring section 20, and second dummy wiring section 30B is arranged along the periphery of first dummy wiring section 30A. Unlike mesh wiring section 20, these dummy wiring sections 30A, 30B do not actually function as antennas.

[0125] As shown in FIG. 14, the first dummy wiring section 30A is composed of repeated dummy wirings 30a1 having a predetermined pattern. The second dummy wiring section 30B is composed of repeated dummy wirings 30a2 having a predetermined pattern. That is, the dummy wiring sections 30A and 30B each include a plurality of dummy wirings 30a1 and 30a2, and each of the dummy wirings 30a1 and 30a2 is electrically independent from the mesh wiring section 20. The dummy wirings 30a1 and 30a2 are regularly arranged throughout the entire dummy wiring sections 30A and 30B, respectively. The dummy wirings 30a1 and 30a2 are spaced apart from each other in the planar direction and protrude above the substrate 11. Each of the dummy wirings 30a1 and 30a2 is electrically independent from the mesh wiring section 20, the power supply section 40, and the other dummy wirings 30a1 and 30a2. The shape of each of the dummy wirings 30a1 and 30a2 is approximately L-shaped in plan view.

[0126] In this case, the dummy wirings 30a1 and 30a2 have a shape in which a portion of the pattern shape of the mesh wiring portion 20 described above is missing. This makes it difficult to visually recognize the difference between the mesh wiring portion 20 and the first dummy wiring portion 30A, and the difference between the first dummy wiring portion 30A and the second dummy wiring portion 30B, and makes it difficult to see the mesh wiring portion 20 arranged on the substrate 11. As shown in FIG. 14, the dummy wirings 30a1 and 30a2 extend parallel to the first directional wiring 21 or the second directional wiring 22. Specifically, the dummy wiring 30a1 includes a first portion 31a1 extending parallel to the first directional wiring 21 and a second portion 32a1 extending parallel to the second directional wiring 22. The dummy wiring 30a2 includes a first portion 31a2 extending parallel to the first directional wiring 21 and a second portion 32a2 extending parallel to the second directional wiring 22.

[0127] The area of ​​each dummy wiring 30a1 in the first dummy wiring section 30A is larger than the area of ​​each dummy wiring 30a2 in the second dummy wiring section 30B. In this case, the line width of each dummy wiring 30a1 is the same as the line width of each dummy wiring 30a2, but this is not limited to this, and the line width of each dummy wiring 30a1 may be wider than the line width of each dummy wiring 30a2. Note that other configurations of the dummy wirings 30a1 and 30a2 are similar to the configuration of the dummy wiring 30a in the third modified example, so detailed description will be omitted here.

[0128] In this modification, the aperture ratios of the mesh wiring section 20 and the multiple dummy wiring sections 30A, 30B preferably increase stepwise from the mesh wiring section 20 toward the dummy wiring sections 30A, 30B farther from the mesh wiring section 20. In other words, the aperture ratio of each dummy wiring section preferably gradually increases from those closer to the mesh wiring section 20 to those farther from it. In this case, the aperture ratio of the first dummy wiring section 30A is preferably greater than that of the mesh wiring section 20. The aperture ratio of the second dummy wiring section 30B is preferably greater than that of the first dummy wiring section 30A. This makes it possible to further obscure the outer edges of the mesh wiring section 20 and the dummy wiring sections 30A, 30B. This makes it possible to further obscure the mesh wiring section 20 on the surface of the image display device 60.

[0129] In this way, by arranging dummy wiring portions 30A and 30B that are electrically independent from mesh wiring portion 20, the outer edge of mesh wiring portion 20 can be made more unclear. This makes mesh wiring portion 20 less visible on the surface of image display device 60, making it difficult for a user of image display device 60 to recognize mesh wiring portion 20 with the naked eye. Note that three or more dummy wiring portions with different aperture ratios may be provided around mesh wiring portion 20.

[0130] Figure 15 shows a third modified example of the wiring board. The modified example shown in Figure 15 differs in the planar shape of the mesh wiring portion 20, but other configurations are substantially the same as the embodiment shown in Figures 1 to 14 described above. In Figure 15, the same parts as those shown in Figures 1 to 14 are given the same reference numerals, and detailed explanations will be omitted.

[0131] 15, the first-directional wiring 21 and the second-directional wiring 22 intersect at an angle (not at a right angle), and each opening 23 is formed in a diamond shape in a plan view. The first-directional wiring 21 and the second-directional wiring 22 are not parallel to either the X direction or the Y direction, but either one of the first-directional wiring 21 and the second-directional wiring 22 may be parallel to the X direction or the Y direction.

[0132] It is also possible to combine the multiple components disclosed in the above embodiment and each modification as needed, or to delete some of the components disclosed in the above embodiment and each modification.

Claims

1. a wiring substrate having a substrate including a first surface and a second surface located opposite to the first surface, a mesh wiring portion disposed on the first surface of the substrate, and a power supply portion electrically connected to the mesh wiring portion; a power supply line electrically connected to the power supply portion via an anisotropic conductive film containing a plurality of conductive particles; the wiring board has an electromagnetic wave transmitting and receiving function, The substrate is transparent, The mesh wiring portion is configured as an antenna, the conductive particles have an average particle size of 3 μm or more and 20 μm or less; A module in which, of the plurality of conductive particles, 20% of the total conductive particles in order of largest particle diameter and 20% of the total conductive particles in order of smallest particle diameter are excluded, and for the remaining 60% of the conductive particles, the value obtained by subtracting the maximum particle diameter from the minimum particle diameter is 60% or less of the average particle diameter.

2. 2. The module according to claim 1, wherein the wiring board has a millimeter wave transmitting and receiving function, and the mesh wiring portion is configured as an array antenna.

3. The module according to claim 1 , wherein the thickness of the anisotropic conductive film is 3 μm or more and 20 μm or less.

4. A wiring board having a substrate including a first surface and a second surface located opposite the first surface, a mesh wiring section disposed on the first surface of the substrate, and a power supply section electrically connected to the mesh wiring section; a power supply line electrically connected to the power supply portion via an anisotropic conductive film containing a plurality of conductive particles; the wiring board has an electromagnetic wave transmitting and receiving function, The substrate is transparent, The mesh wiring portion is configured as an antenna, the conductive particles have an average particle size of 3 μm or more and 20 μm or less; A module, wherein a first oxide film is formed on a surface of the power supply portion, and the conductive particles penetrate the first oxide film.

5. A wiring board having a substrate including a first surface and a second surface located opposite the first surface, a mesh wiring section disposed on the first surface of the substrate, and a power supply section electrically connected to the mesh wiring section; a power supply line electrically connected to the power supply portion via an anisotropic conductive film containing a plurality of conductive particles; the wiring board has an electromagnetic wave transmitting and receiving function, The substrate is transparent, The mesh wiring portion is configured as an antenna, the conductive particles have an average particle size of 3 μm or more and 20 μm or less; The power supply line has a substrate and a metal wiring portion laminated on the substrate, a second oxide film is formed on the surface of the metal wiring portion, and the conductive particles penetrate the second oxide film.

6. The module according to claim 1 , wherein the distance between the mesh wiring portions is 1 mm or more and 5 mm or less.

7. 2. The module according to claim 1, further comprising a dummy wiring section provided around said mesh wiring section and electrically independent from said mesh wiring section.

8. 8. The module according to claim 7, wherein a plurality of the dummy wiring sections are provided, and the aperture ratios of the mesh wiring section and the dummy wiring section increase stepwise from the mesh wiring section toward the dummy wiring section farther from the mesh wiring section.

9. A module according to any one of claims 1 to 8; a first adhesive layer located on the first surface side of the substrate; a second adhesive layer located on the second surface side of the substrate, A laminate for an image display device, wherein a portion of the substrate is disposed in a portion of the region between the first adhesive layer and the second adhesive layer.

10. The laminate for an image display device according to claim 9 ; and a display device laminated on the laminate for an image display device.

11. A method for manufacturing a module, comprising: providing a substrate including a first surface and a second surface opposite the first surface; forming a mesh wiring portion and a power supply portion electrically connected to the mesh wiring portion on the first surface of the substrate to fabricate a wiring substrate; and electrically connecting a power supply line to the power supply portion via an anisotropic conductive film containing a plurality of conductive particles, the wiring board has an electromagnetic wave transmitting and receiving function, The substrate is transparent, The mesh wiring portion is configured as an antenna, the conductive particles have an average particle size of 3 μm or more and 20 μm or less; A method for manufacturing a module, wherein, of the plurality of conductive particles, 20% of the total conductive particles in order from the largest particle diameter and 20% of the total conductive particles in order from the smallest particle diameter are excluded, and for the remaining 60% of the conductive particles, the value obtained by subtracting the maximum particle diameter from the minimum particle diameter is 60% or less of the average particle diameter.

12. A method for manufacturing a module, comprising: providing a substrate including a first surface and a second surface opposite the first surface; forming a mesh wiring portion and a power supply portion electrically connected to the mesh wiring portion on the first surface of the substrate to fabricate a wiring substrate; and electrically connecting a power supply line to the power supply portion via an anisotropic conductive film containing a plurality of conductive particles, the wiring board has an electromagnetic wave transmitting and receiving function, The substrate is transparent, The mesh wiring portion is configured as an antenna, the conductive particles have an average particle size of 3 μm or more and 20 μm or less; A method for manufacturing a module, wherein a first oxide film is formed on a surface of the power supply portion, and the conductive particles penetrate the first oxide film.

13. A method for manufacturing a module, comprising: providing a substrate including a first surface and a second surface opposite the first surface; forming a mesh wiring portion and a power supply portion electrically connected to the mesh wiring portion on the first surface of the substrate to fabricate a wiring substrate; and electrically connecting a power supply line to the power supply portion via an anisotropic conductive film containing a plurality of conductive particles, the wiring board has an electromagnetic wave transmitting and receiving function, The substrate is transparent, The mesh wiring portion is configured as an antenna, the conductive particles have an average particle size of 3 μm or more and 20 μm or less; a second oxide film formed on a surface of the metal wiring portion; and a second oxide film formed on a surface of the metal wiring portion.

Images