Light-transmitting substrate

Abstract

This light-transmitting substrate (1) comprises: a base material (10) made of a transparent resin material; a first electrode (20); a second electrode (40) separated from the first electrode (20); and mesh-shaped dummy wiring (60) separated from the first electrode (20) and the second electrode (40). The first electrode (20) has mesh-shaped first electrode wiring (21), a first pad (22), and a second pad (23). The second electrode (40) has mesh-shaped second electrode wiring (41), a third pad (42), and a fourth pad (43). The dummy wiring (60) is positioned between the first electrode wiring (21) and the second electrode wiring (41).

Description

Light-transmitting substrate

[0001] The present disclosure relates to a light-transmitting substrate.

[0002] Conventionally, regarding light-transmitting substrates, for example, the technology disclosed in Patent Document 1 (a conductive light-transmitting substrate) is known.

[0003] Patent Document 1 discloses a light-emitting unit. The light-emitting unit includes a light-emitting panel (a light-transmitting substrate). The light-transmitting substrate has a pair of transparent films (base materials) arranged opposite to each other. A conductor layer is formed on a surface of one base material that faces the other base material. As shown in FIG. 7 of Patent Document 1, the conductor layer is formed of a mesh-shaped conductor pattern (electrode wiring). The base material is entirely covered by the electrode wiring. The electrode wiring is made of a metal material such as copper or silver. Visible light incident on the light-transmitting substrate can pass through the mesh-shaped electrode wiring. Therefore, the light-transmitting substrate can maintain light transmittance.

[0004] The electrode wiring is divided by slits. A pair of connection pads (pads) are provided on the electrode wiring. The pads are provided at edges of adjacent electrode wirings. The pads are positioned opposite to each other across the slit. A light-emitting element is connected to the pads.

[0005] Japanese Unexamined Patent Publication No. 2019-134184

[0006] By the way, in the light-transmitting substrate disclosed in Patent Document 1, the electrode wiring is divided by slits, and nothing is provided in the slit portions. Therefore, when the width of the slit is large, the slit may become noticeable due to the difference between the aperture ratio of the electrode wiring and the aperture ratio of the slit. Accordingly, it has been considered to reduce the difference in aperture ratio by providing mesh-shaped dummy wiring (dummy wiring) similar to the electrode wiring in the slit.

[0007] However, when dummy wiring is provided, the dummy wiring is arranged in the immediate vicinity of the electrode wiring and the pads, so there is a concern that adjacent electrode wiring and pads may be electrically conducted via the dummy wiring.

[0008] This disclosure is made in view of the above, and its purpose is to make the electrode wiring and dummy wiring less visible while maintaining electrical insulation between the electrode wiring and pads and the dummy wiring.

[0009] To achieve the above objective, the light-transmitting substrate comprises a transparent resin material base, a first electrode provided on the upper surface of the base, a second electrode provided on the upper surface of the base and spaced apart from the first electrode, and a mesh-like dummy wiring provided on the upper surface of the base and spaced apart from the first and second electrodes. The first electrode has a mesh-like first electrode wiring, a first pad connected to the first electrode wiring, and a second pad connected to the first electrode wiring and in parallel with the first pad. The second electrode has a mesh-like second electrode wiring, a third pad connected to the second electrode wiring and spaced apart from the first pad, and a fourth pad connected to the second electrode wiring and in parallel with the third pad. The dummy wiring is located between the first electrode wiring and the second electrode wiring. The dummy wiring is located between the first pad and the second pad. The dummy wiring is located between the third pad and the fourth pad.

[0010] According to this disclosure, it is possible to make the electrode wiring and dummy wiring less visible while maintaining electrical insulation between them and the dummy wiring.

[0011] Figure 1 is a diagram showing a light-transmitting substrate according to Embodiment 1 of the present disclosure. Figure 2 is a partially enlarged view of part II shown in Figure 1. Figure 3 is a cross-sectional view taken along line III-III shown in Figure 2. Figure 4 is a partially enlarged view of part IV shown in Figure 2. Figure 5 is a partially enlarged view of part V shown in Figure 2. Figure 6 is a partially enlarged view of part VI shown in Figure 2. Figure 7A is a partially enlarged view of part VII shown in Figure 2. Figure 7B is a diagram corresponding to Figure 7A according to Modification 1. Figure 7C is a diagram corresponding to Figure 7A according to Modification 2. Figure 7D is a diagram corresponding to Figure 7A according to Modification 3. Figure 7E is a diagram corresponding to Figure 7A according to Modification 4. Figure 8 is a diagram corresponding to Figure 1 according to Embodiment 2. Figure 9 is a partially enlarged view of part IX shown in Figure 8. Figure 10 is a diagram corresponding to Figure 8 according to Modification 5.

[0012] Embodiments of the present disclosure will be described in detail below with reference to the drawings. The following description of preferred embodiments is illustrative in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0013] [Embodiment 1] (Light-transmitting substrate) Figures 1 and 2 show a light-transmitting substrate 1 according to Embodiment 1 of the present disclosure. The light-transmitting substrate 1 comprises a base material 10, a first electrode 20, a second electrode 40, and dummy wiring 60. The light-transmitting substrate 1 further comprises a first signal wiring 30 and a second signal wiring 50.

[0014] The light-transmitting substrate 1 is a component for display devices. The light-transmitting substrate 1 is used as a component for display devices in in-vehicle equipment, personal computer displays, mobile phones, personal digital assistants, portable game consoles, photocopiers, ticket vending machines, ATMs, watches, and the like.

[0015] A light-transmitting substrate 1 is connected to light-emitting elements (not shown), a power supply (not shown), and a control device (not shown). The light-emitting elements are arranged on the light-transmitting substrate 1 in the shape of any character or graphic. At least two or more light-emitting elements are provided. By controlling the conductivity to the light-emitting elements with the control device, any character or graphic can be displayed on the light-transmitting substrate 1.

[0016] (Substrate) As shown in Figure 1, the light-transmitting substrate 1 comprises a substrate 10. The substrate 10 is a transparent resin material.

[0017] The light-transmitting substrate 1 may be colored. For example, when attaching the light-transmitting substrate 1 to a housing (not shown), it may be necessary to make it indistinguishable from the housing in appearance. In such cases, the light-transmitting substrate 1 may have the same color as the housing. Also, if the light-transmitting substrate 1 is not transparent, the visibility of the first electrode wiring 21 will be suppressed.

[0018] The base material 10 is formed in a sheet shape. The thickness of the base material 10 is, for example, 10 μm or more and 200 μm or less.

[0019] As shown in Figure 3, the base material 10 has a transparent base material 11 and an insulating layer 12.

[0020] The transparent substrate 11 is made of a transparent resin material. Examples of transparent resin materials include PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PC (polycarbonate), COP (cycloolefin polymer), COC (cycloolefin copolymer), PMMA (polymethyl methacrylate resin), and PI (polyimide). The transparent substrate 11 may also be colored.

[0021] The insulating layer 12 is laminated on the upper surface 11a side of the transparent substrate 11. The insulating layer 12 is made of a resin material that has insulating and permeable properties. The thickness of the insulating layer 12 is greater than the depth of the groove 12b (dimension GD shown in Figure 3), which will be described later. The insulating layer 12 may be colored.

[0022] (Groove) As shown in Figure 3, a groove 12b is provided on the upper surface 10a of the base material 10 (upper surface 12a of the insulating layer 12). The groove 12b has a bottomed shape, recessed from the upper surface 12a of the insulating layer 12 toward the thickness direction of the insulating layer 12. The depth (dimension GD) of the groove 12b is set to, for example, 0.2 μm or more and 5.0 μm or less.

[0023] The light-transmitting substrate 1 according to this embodiment 1 is provided with a plurality of grooves 12b. The groove widths of each groove 12b may be the same size, or they may be different sizes.

[0024] The groove portion 12b has a lower surface 12c and a groove side surface 12d. Here, the "groove side surface 12d" is a surface of the base material 10 that forms the groove portion 12b and is not parallel to the upper surface 10a of the base material 10 (the upper surface 12a of the insulating layer 12).

[0025] The groove side surface 12d is formed in a tapered shape, widening upward (towards the opening side of the groove 12b) from the lower surface 12c of the groove 12b. Specifically, in the thickness direction of the base material 10, the groove side surface 12d is inclined upward (towards the opening side of the groove 12b) from the lower surface 12c of the groove 12b to the left or right side of the paper in Figure 3. As a result, in this embodiment, the groove width dimension GW1 at the opening of the groove 12b is larger than the width dimension GW2 at the lower surface 12c of the groove 12b.

[0026] The groove width dimension GW1 of the groove portion 12b is, for example, 0.5 μm or more and 20 μm or less. The aspect ratio of the groove portion 12b shown in Figure 3 (the value obtained by dividing the depth dimension GD in the groove portion 12b by the groove width dimension GW1) is, for example, 0.1 or more.

[0027] (First Electrode) As shown in Figures 1 and 2, the first electrode 20 is provided on the upper surface 10a of the base material 10. The first electrode 20 has a first electrode wiring 21, a first pad 22, a second pad 23, and a first signal wiring 30.

[0028] (First electrode wiring) As shown in Figures 1 and 2, the light-transmitting substrate 1 according to this embodiment 1 is provided with a plurality of first electrode wirings 21 (see Figure 1). The first electrode wirings 21 have metal fine wires 210. The line width of the metal fine wires 210 is, for example, 0.5 μm or more and 20 μm or less.

[0029] The metal wires 210 are formed in a straight line. The metal wires 210 extend diagonally with respect to the X and Y directions shown in Figure 1. Multiple metal wires 210 are arranged at intervals from each other. The first electrode wiring 21 is mesh-like. In this disclosure, the term "mesh-like" is not limited to that formed by straight metal wires 210. That is, mesh-like structures formed by arcs, curves, or combinations thereof are also referred to as mesh-like.

[0030] Furthermore, the metal wire 210 is not limited to being straight. For example, as shown in Figure 7E, the metal wire 210 may be formed in a curved shape. Also, although not shown, a plurality of metal wires 210 may include both straight and curved metal wires 210. Moreover, the metal wire 210 may extend along the X and Y directions shown in Figure 1.

[0031] The light-transmitting substrate 1 comprises a plurality of cells 65. Each cell 65 is formed in a closed manner by a plurality of first electrode wirings 21. The cells in this embodiment have a rhombic shape. However, the shape of the cell 65 is not limited to a rhombic shape, and may be other polygonal shapes (triangle, square, etc.) or circular shapes.

[0032] (Cross-sectional structure of metal wires) The cross-sectional structure of the metal wires 210 will now be described. Each metal wire 210 contains conductive metal embedded in each groove 12b provided on the surface of the base material 10. As shown in Figure 3, each metal wire 210 is composed of an adhesion layer 210a, a seed layer 210b, a conductive layer 210c, and a blackening layer 210d.

[0033] The adhesion layer 210a is an element that ensures the adhesion of the seed layer 210b to the groove 12b. The adhesion layer 210a is a metal layer composed of a metal nitride or metal oxide containing at least one metal selected from the group consisting of Ti, Ni, Al, V, W, Ta, Si, Cr, Ag, Mo, Cu, and Zn. The adhesion layer 210a may be a single layer or a laminate of multiple layers with different compositions. The adhesion layer 210a is laminated onto the groove 12b in the form of a thin film, for example, by vapor deposition or sputtering.

[0034] The seed layer 210b has the function of bonding the conductive layer 210c to the adhesion layer 210a. Specifically, in this embodiment, the seed layer 210b functions as a cathode for depositing a plating solution containing copper (Cu) or the like onto the adhesion layer 210a during an electroplating process to form the conductive layer 210c. The seed layer 210b is deposited onto the adhesion layer 210a as a thin film by, for example, vapor deposition or sputtering.

[0035] The conductive layer 210c is made of a conductive metal such as copper (Cu). The conductive layer 210c is formed, for example, by electroplating. When electroplating is performed, the seed layer 210b and the conductive layer 210c are formed integrally. As a result, the interface between the seed layer 210b and the conductive layer 210c becomes indistinguishable. Although copper (Cu) is suitable as the main component of the plating solution used in the electroplating process, other metals (e.g., silver, gold) may also be included.

[0036] The blackened layer 210d has the function of making the metal fine wires 210 difficult to see when viewed from above the light-transmitting substrate 1. The blackened layer 210d is laminated on the surface of the conductive layer 210c. The blackened layer 210d is formed by replacing (blackening) copper crystal grains located at the boundaries between copper crystal grains located on the surface of the conductive layer 210c with palladium. The thickness of the blackened layer 210d is, for example, 7 nm to 10 nm.

[0037] (Second electrode) As shown in Figures 1 and 2, the second electrode 40 is provided on the upper surface 10a of the base material 10 and is separated from the first electrode 20. The second electrode 40 has a second electrode wiring 41, a third pad 42, a fourth pad 43, and a second signal wiring 50.

[0038] (Second Electrode Wiring) As shown in Figures 1 and 2, the light-transmitting substrate 1 according to this embodiment is provided with a plurality of second electrode wirings 41 (see Figure 1). The second electrode wirings 41 have fine metal wires 410. The second electrode wirings 41 are mesh-like. Hereafter, the second electrode wirings 41 have the same structure as the first electrode wirings 21, so their description will be omitted.

[0039] (First Pad) The first pad 22 is a pad for mounting a light-emitting element (not shown). As shown in Figure 2, the first pad 22 is connected to the first electrode wiring 21. The first pad 22 is located between the first electrode wiring 21 and the second electrode wiring 41. The first pad 22 is provided with a first pad portion 22a and a first extraction portion 22b. In other words, the first pad 22 comprises a first pad portion 22a and a first extraction portion 22b.

[0040] (First pad section) The first pad section 22a is a connection pattern for connecting a light-emitting element (not shown) and the first electrode wiring 21.

[0041] (First extraction section) The first extraction section 22b is a connection assist pattern for assisting the connection between the metal wire 210 and the pad. As shown in Figures 2 and 5, the first extraction section 22b extends from the first pad section 22a. The first extraction section 22b connects to the first electrode wiring 21. Therefore, the first pad 22 is reliably connected to the mesh-like first electrode wiring 21 regardless of the position of the end of the first electrode wiring 21. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60 difficult to see while maintaining electrical insulation between the first electrode wiring 21 and the second electrode wiring 41 and the dummy wiring 60, between the first pad 22 and the second pad 23 and the dummy wiring 60, and between the third pad 42 and the fourth pad 43 and the dummy wiring 60. Furthermore, it is possible to reduce variations in the way heat is transferred between the first electrode wiring 21 and the first pad 22, thereby reducing variations in soldering quality.

[0042] Incidentally, the first electrode wiring 21 is formed in a mesh shape. The edge of the first electrode wiring 21 facing the second electrode wiring 41 is in a state where the mesh is cut at an arbitrary position. In other words, the ends of the metal fine wires 210 are arranged at arbitrary intervals along the edge of the first electrode wiring 21. On the other hand, the first pad 22 is provided at the edge of the area where the first electrode wiring 21 is installed. At this time, it is not possible to guarantee the number of ends of the metal fine wires 210 that contact the first pad 22, or the part of the metal fine wires 210 that contacts the first pad 22. Therefore, there is a risk that the way heat is transferred between the first electrode wiring 21 and the first pad 22, or between the first electrode wiring 21 and the second pad 23, may differ greatly. This raises concerns that the quality of soldering between each electrode wiring and each pad may vary greatly.

[0043] With this configuration, the first pad 22 is reliably connected to the mesh-shaped first electrode wiring 21 regardless of the position of the end portion of the thin metal wire 210. In addition, a sufficient heat transfer path between the first electrode wiring 21 and the first pad 22 can be sufficiently secured. This makes it difficult to visually recognize the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 while maintaining electrical insulation between the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60, between the first pad 22, the second pad 23 and the dummy wiring 60, and between the third pad 42, the fourth pad 43 and the dummy wiring 60. Furthermore, variation in heat transfer between the first electrode wiring 21 and the first pad 22 can be reduced, and variation in soldering quality can be reduced.

[0044] (First Pair of Pads) The first pair of pads 220 is an electrode pad for inputting power supply for lighting a light-emitting element not shown in the figure. As shown in FIG. 1 and FIG. 2, the first pair of pads 220 is located between the first electrode wiring 21 and the second electrode wiring 41.

[0045] (Second Pad) The second pad 23 is a pad for mounting a light-emitting element not shown in the figure. As shown in FIG. 2, the second pad 23 is connected to the first electrode wiring 21 and connected in parallel with the first pad 22. The first pad 22 and the second pad 23 are located between the first electrode wiring 21 and the second electrode wiring 41. As shown in FIG. 2, the second pad 23 is provided with a second pad portion 23a and a second lead-out portion 23b. Hereinafter, since the structure of the second pad 23 is the same as that of the first pad 22, description thereof is omitted.

[0046] (Second Lead-out Portion) The second lead-out portion 23b is a connection auxiliary pattern for assisting the connection between the thin metal wire 210 and the pad. Hereinafter, since the structure of the second lead-out portion 23b is the same as that of the first lead-out portion 22b, description thereof is omitted.

[0047] (Second Pair of Pads) The second pair of pads 230 is an electrode pad for inputting power supply for lighting a light-emitting element. Hereinafter, since the structure of the second pair of pads 230 is the same as that of the first pair of pads 220, description thereof is omitted.

[0048] (Third Pad) The third pad 42 is a pad for mounting a light-emitting element (not shown). As shown in FIG. 2, the third pad 42 is connected to the second electrode wiring 41 and spaced apart from the first pad 22. The third pad 42 is located between the first electrode wiring 21 and the second electrode wiring 41. The third pad 42 is provided with a third pad portion 42a and a third lead-out portion 42b. In other words, the third pad 42 includes the third pad portion 42a and the third lead-out portion 42b. Hereinafter, since the structure of the third pad 42 is the same as that of the first pad 22, the description thereof is omitted.

[0049] (Third Lead-out Portion) The third lead-out portion 42b is a connection auxiliary pattern for assisting the connection between the thin metal wire 410 and the pad. As shown in FIG. 2 and FIG. 5, the third lead-out portion 42b extends from the third pad portion 42a. The third lead-out portion 42b is connected to the second electrode wiring 41. Hereinafter, since the structure of the third lead-out portion 42b is the same as that of the first lead-out portion 22b, the description thereof is omitted.

[0050] (Third Pair of Pads) The third pair of pads 420 is an electrode pad for inputting power supply power for lighting the light-emitting element. Hereinafter, since the structure of the third pair of pads 420 is the same as that of the first pair of pads 220, the description thereof is omitted.

[0051] (Fourth Pad) The fourth pad 43 is a pad for mounting a light-emitting element (not shown). As shown in FIG. 2, the fourth pad 43 is connected to the second electrode wiring 41 and connected in parallel with the third pad 42. The fourth pad 43 is located between the first electrode wiring 21 and the second electrode wiring 41. As shown in FIG. 2, the fourth pad 43 is provided with a fourth pad portion 43a and a fourth lead-out portion 43b. Hereinafter, since the structure of the fourth pad 43 is the same as that of the first pad 22, the description thereof is omitted.

[0052] (Fourth Lead-out Portion) The fourth lead-out portion 43b is a connection auxiliary pattern for assisting the connection between the thin metal wire 410 and the pad. Hereinafter, since the structure of the fourth lead-out portion 43b is the same as that of the first lead-out portion 22b, the description thereof is omitted.

[0053] (Fourth pair of pads) The fourth pair of pads 430 are electrode pads for inputting power to light up the light-emitting element. The structure of the fourth pair of pads 430 is the same as that of the first pair of pads 220, so the explanation will be omitted below.

[0054] Specifically, the first pad 22 and the second pad 23 are located on the edge of the first electrode wiring 21 facing the second electrode wiring 41 and protrude from the first electrode wiring 21 toward the second electrode wiring 41. On the other hand, the third pad 42 and the fourth pad 43 are located on the edge of the second electrode wiring 41 facing the first electrode wiring 21 and protrude from the second electrode wiring 41 toward the first electrode wiring 21. Therefore, the first pad 22, the second pad 23, the third pad 42, and the fourth pad 43 are arranged between the first electrode wiring 21 and the second electrode wiring 41.

[0055] Therefore, the distance between the first electrode wiring 21 and the second electrode wiring 41 can be increased. Consequently, the area of ​​the dummy wiring 60 can be increased. In addition, the insulation between the first electrode wiring 21 and the second electrode wiring 41 can be improved. As a result, the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60 can be made less visible while maintaining electrical insulation between the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60, the first pad 22, the second pad 23 and the dummy wiring 60, and the third pad 42, the fourth pad 43 and the dummy wiring 60.

[0056] (First signal wiring) As shown in Figure 1, the first signal wiring 30 is electrically connected to the first pad 22. One end of the first signal wiring 30 is connected to the first electrode wiring 21. The other end of the first signal wiring 30 is provided with a first terminal portion 35. An input voltage is applied to the first signal wiring 30.

[0057] The first signal wiring 30 is formed by a plurality of fine metal wires 210. The wire width of the plurality of fine metal wires 210 forming the first signal wiring 30 is 6 μm or more. The plurality of fine metal wires 210 forming the first signal wiring 30 are in a ladder or mesh shape.

[0058] (First terminal section) The first terminal section 35 is formed from a thin metal wire 210. The first terminal section 35 is electrically connected to a flexible wiring board (not shown) via, for example, an anisotropic conductive film (ACF).

[0059] (Second signal wiring) As shown in Figure 1, the second signal wiring 50 is electrically connected to the third pad 42. One end of the second signal wiring 50 is connected to the second electrode wiring 41. The other end of the second signal wiring 50 is provided with a second terminal 55. An output voltage different from the input voltage is applied to the second signal wiring 50. The structure of the second signal wiring 50 and the second terminal 55 is the same as that of the first signal wiring 30, so a detailed explanation will be omitted below.

[0060] In the above description, an input voltage is applied to the first signal wiring 30 and an output voltage is applied to the second signal wiring 50. However, the applied voltages may be reversed. That is, an output voltage may be applied to the first signal wiring 30 and an input voltage may be applied to the second signal wiring 50.

[0061] (Dummy Wiring) As shown in Figures 1 and 2, the dummy wiring 60 is provided on the upper surface 10a of the base material 10 and is spaced apart from the first electrode 20 and the second electrode 40. The dummy wiring 60 is located between the first electrode wiring 21 and the second electrode wiring 41. The dummy wiring 60 is located between the first pad 22 and the second pad 23. The dummy wiring 60 is located between the third pad 42 and the fourth pad 43.

[0062] As shown in Figures 1 and 2, the dummy wiring 60 is mesh-like. The dummy wiring 60 has thin metal wires 600. Since the dummy wiring 60 has the same structure as the first electrode wiring 21, its description is omitted.

[0063] This configuration makes it possible to reduce the difference between the light aperture ratio of the portion of the light-transmitting substrate 1 where the first electrode wiring 21 and the second electrode wiring 41 are formed and the light aperture ratio of the portion where the first electrode wiring 21 and the second electrode wiring 41 are not formed. Furthermore, the dummy wiring 60 is electrically insulated from the first electrode wiring 21, the second electrode wiring 41, the first pad 22, the second pad 23, the third pad 42, and the fourth pad 43. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 difficult to see while maintaining electrical insulation between the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60, between the first pad 22, the second pad 23, and the dummy wiring 60, and between the third pad 42, the fourth pad 43, and the dummy wiring 60.

[0064] As shown in Figures 1 and 2, the aperture ratio of the dummy wiring 60 is equal to that of the first electrode wiring 21 and equal to that of the second electrode wiring 41. Here, "equal aperture ratios" does not only mean that the aperture ratios are perfectly identical, but also that an error of ±3% or less is acceptable.

[0065] This configuration makes it possible to reduce the difference between the light aperture ratio of the portion of the light-transmitting substrate 1 where the first electrode wiring 21 and the second electrode wiring 41 are formed and the light aperture ratio of the portion where the first electrode wiring 21 and the second electrode wiring 41 are not formed. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60 difficult to see while maintaining electrical insulation between the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60, between the first pad 22, the second pad 23 and the dummy wiring 60, and between the third pad 42, the fourth pad 43 and the dummy wiring 60.

[0066] As shown in Figure 4, the dummy wiring 60 includes a first end 60a and a second end 60b. The first end 60a is located in the dummy wiring 60 closest to the first electrode 20. The second end 60b is located in the dummy wiring 60 closest to the second electrode 40. The dummy wiring 60 is electrically insulated between the first end 60a and the second end 60b. The first end 60a or the second end 60b is the edge of the region where the dummy wiring 60 is provided.

[0067] This configuration prevents the first electrode wiring 21 and the second electrode wiring 41 from becoming electrically connected by the dummy wiring 60. This makes it possible to maintain electrical insulation between the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 while making the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 difficult to see.

[0068] As shown in Figure 5, the dummy wiring 60 includes a third end 60d and a fourth end 60e. The third end 60d is located in the dummy wiring 60 closest to the third pad 42. The fourth end 60e is located in the dummy wiring 60 closest to the second pad 23. The dummy wiring 60 is electrically insulated between the third end 60d and the fourth end 60e. The third end 60d and the fourth end 60e are the edges of the region where the dummy wiring 60 is provided.

[0069] This configuration prevents the second pad 23 and the third pad 42 from becoming electrically connected by the dummy wiring 60. This makes it possible to maintain electrical insulation between the second pad 23, the third pad 42, and the dummy wiring 60 while making the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 difficult to see.

[0070] (Modification 1) Figure 6 shows a modified example of the location where the metal wire 600 is cut in the dummy wiring 60. As shown in Figure 6, the dummy wiring 60 further includes a first cell 650 and a second cell 660. The first cell 650 includes a first vertex 65a and a cut first side 65b. The first cell 650 is formed in a rectangular shape. The second cell 660 has the first vertex 65a as its vertex and includes a cut second side 66b. The second cell 660 is formed in a rectangular shape. The position of the first side 65b in the first cell 650 is different from the position of the second side 66b in the second cell 660. That is, the pattern of the dummy wiring 60 corresponds to a shape in which a part of the metal wire 600 is cut from the pattern in which the metal wire 600 of the first electrode wiring 21 is arranged. In the first cell 650 and the second cell 660, which are adjacent and share the first vertex 65a, if the first cell 650 is translated parallel to the position of the second cell 660 and superimposed, the cut first side 65b of the first cell 650 and the cut second side 66b of the second cell 660 will not overlap. Therefore, the cuts in the dummy wiring 60 will be irregularly arranged and less noticeable.

[0071] This makes it possible to make the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 difficult to see while maintaining electrical insulation between the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60, between the first pad 22, the second pad 23, and the dummy wiring 60, and between the third pad 42, the fourth pad 43, and the dummy wiring 60.

[0072] (Modification 2) Figure 7B shows a modification of the first extraction portion 22b in the first pad 22. As shown in Figure 7B, the first pad 22 includes a first extraction portion 22b extending from the first pad portion 22a. The first extraction portion 22b is connected to the first electrode wiring 21. The first pad portion 22a is physically connected to the first electrode wiring 21. The first extraction portion 22b extends from the side of the first pad portion 22a that is connected to the first electrode wiring 21 in a direction along the edge of the region where the first electrode wiring 21 is provided. The first extraction portion 22b connects the first pad portion 22a to the metal fine wire 210 of the first electrode wiring 21. The width of the wire of the first extraction portion 22b is 0.5 μm or more and 20 μm or less. The length of the wire of the first extraction portion 22b is at least twice the spacing between the metal fine wires 210. In other words, the first extraction portion 22b extends over a length of at least two meshes.

[0073] The first pad portion 22a is physically connected to the first electrode wiring 21. Therefore, the number of contact points between the first electrode wiring 21 and the first pad 22 can be increased. In other words, a sufficient path for heat transfer can be secured between the first electrode wiring 21 and the first pad 22.

[0074] (Modification 3) Figure 7C shows a modification of the first extraction portion 22b in the first pad 22. As shown in Figure 7C, the first pad 22 includes a first extraction portion 22b extending from the first pad portion 22a. The first extraction portion 22b is connected to the first electrode wiring 21. The first pad portion 22a is physically connected to the first electrode wiring 21. The first extraction portion 22b extends from the side of the first pad portion 22a that is connected to the first electrode wiring 21 in a direction toward the interior of the region where the first electrode wiring 21 is provided. The first extraction portion 22b connects the first pad portion 22a to the metal fine wires 210 of the first electrode wiring 21. The width of the wire of the first extraction portion 22b is 0.5 μm or more and 20 μm or less. The length of the wire of the first extraction portion 22b is more than twice the spacing of the metal fine wires 210. In other words, the first extraction portion 22b extends over a length of more than 2 meshes.

[0075] Incidentally, the first electrode wiring 21 is formed in a mesh shape. The edge of the first electrode wiring 21 facing the second electrode wiring 41 is in a state where the mesh is cut at an arbitrary position. In other words, the ends of the metal fine wires 210 are arranged at arbitrary intervals along the edge of the first electrode wiring 21. On the other hand, the first pad 22 is provided at the edge of the area where the first electrode wiring 21 is installed. At this time, it is not possible to guarantee the number of ends of the metal fine wires 210 that contact the first pad 22, or the part of the metal fine wires 210 that contacts the first pad 22. Therefore, there is a concern that the way heat is transferred between the first electrode wiring 21 and the first pad 22, or between the first electrode wiring 21 and the second pad 23, may differ greatly, leading to large variations in the quality of soldering between each electrode wiring and each pad.

[0076] With this configuration, the first pad 22 is reliably connected to the mesh-like first electrode wiring 21 regardless of the position of the end of the metal wire 210. Furthermore, a sufficient path for heat transfer can be secured between the first electrode wiring 21 and the first pad 22. This makes it difficult to see the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60 while maintaining electrical insulation between the first electrode wiring 21 and the second electrode wiring 41 and the dummy wiring 60, between the first pad 22 and the second pad 23 and the dummy wiring 60, and between the third pad 42 and the fourth pad 43 and the dummy wiring 60. In addition, variations in the way heat is transferred between the first electrode wiring 21 and the first pad 22 can be reduced, thereby reducing variations in solder quality.

[0077] (Modification 4) Figure 7D shows a modification of the first extraction portion 22b in the first pad 22. As shown in Figure 7D, the first pad 22 includes a first extraction portion 22b extending from the first pad portion 22a. The first extraction portion 22b is connected to the first electrode wiring 21. The first pad portion 22a is physically connected to the first electrode wiring 21. The first extraction portion 22b extends from the edge of the first pad portion 22a that is connected to the first electrode wiring 21, in a direction along the edge of the region where the first electrode wiring 21 is provided, and also extends inward. The first extraction portion 22b connects the first pad portion 22a to the metal fine wires 210 of the first electrode wiring 21. The width of each wire in the first extraction portion 22b is 10 μm or less. The length of each wire in the first extraction portion 22b is at least twice the spacing between the metal fine wires 210. In other words, the first extraction portion 22b extends over a length of at least two meshes.

[0078] Incidentally, the first electrode wiring 21 is formed in a mesh shape. The edge of the first electrode wiring 21 facing the second electrode wiring 41 is in a state where the mesh is cut at an arbitrary position. In other words, the ends of the metal fine wires 210 are arranged at arbitrary intervals along the edge of the first electrode wiring 21. On the other hand, the first pad 22 is provided at the edge of the area where the first electrode wiring 21 is installed. At this time, it is not possible to guarantee the number of ends of the metal fine wires 210 that contact the first pad 22, or the part of the metal fine wires 210 that contacts the first pad 22. Therefore, there is a concern that the way heat is transferred between the first electrode wiring 21 and the first pad 22, or between the first electrode wiring 21 and the second pad 23, may differ greatly, leading to large variations in the quality of soldering between each electrode wiring and each pad.

[0079] With this configuration, the first pad 22 is reliably connected to the mesh-like first electrode wiring 21 regardless of the position of the end of the metal wire 210. Furthermore, a sufficient path for heat transfer can be secured between the first electrode wiring 21 and the first pad 22. This makes it difficult to see the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60 while maintaining electrical insulation between the first electrode wiring 21 and the second electrode wiring 41 and the dummy wiring 60, between the first pad 22 and the second pad 23 and the dummy wiring 60, and between the third pad 42 and the fourth pad 43 and the dummy wiring 60. In addition, variations in the way heat is transferred between the first electrode wiring 21 and the first pad 22 can be reduced, thereby reducing variations in solder quality.

[0080] (Modification 5) Figure 7E shows a modified mesh shape of the first electrode wiring 21 and the second electrode wiring 41. As shown in Figure 7E, the first pad 22 includes a first extraction portion 22b extending from the first pad portion 22a. The first extraction portion 22b is connected to the first electrode wiring 21. The first pad portion 22a is physically connected to the first electrode wiring 21. The first extraction portion 22b has the same structure as in Modification 1, so its description is omitted.

[0081] Incidentally, the first electrode wiring 21 is formed in a mesh shape. The edge of the first electrode wiring 21 facing the second electrode wiring 41 is in a state where the mesh is cut at an arbitrary position. In other words, the ends of the metal fine wires 210 are arranged at arbitrary intervals along the edge of the first electrode wiring 21. On the other hand, the first pad 22 is provided at the edge of the area where the first electrode wiring 21 is installed. At this time, it is not possible to guarantee the number of ends of the metal fine wires 210 that contact the first pad 22, or the part of the metal fine wires 210 that contacts the first pad 22. Therefore, there is a concern that the way heat is transferred between the first electrode wiring 21 and the first pad 22, or between the first electrode wiring 21 and the second pad 23, may differ greatly, leading to large variations in the quality of soldering between each electrode wiring and each pad.

[0082] With this configuration, the first pad 22 is reliably connected to the mesh-like first electrode wiring 21 regardless of the position of the end of the metal wire 210. Furthermore, a sufficient path for heat transfer can be secured between the first electrode wiring 21 and the first pad 22. This makes it difficult to see the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60 while maintaining electrical insulation between the first electrode wiring 21 and the second electrode wiring 41 and the dummy wiring 60, between the first pad 22 and the second pad 23 and the dummy wiring 60, and between the third pad 42 and the fourth pad 43 and the dummy wiring 60. In addition, variations in the way heat is transferred between the first electrode wiring 21 and the first pad 22 can be reduced, thereby reducing variations in solder quality.

[0083] Although the first electrode wiring 21 has been described as being formed in a mesh shape, it may also have a random shape.

[0084] [Embodiment 2] A light-transmitting substrate 1 according to Embodiment 2 is shown in Figures 8 and 9. The light-transmitting substrate 1 according to Embodiment 2 differs from the light-transmitting substrate 1 according to Embodiment 1 in that the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 are in a ladder shape. The same configuration as in Embodiment 1 will be omitted from the description below, and only the different parts will be described.

[0085] (First Electrode) As shown in Figures 8 and 9, the first electrode 20 is provided on the upper surface 10a of the base material 10. The first electrode 20 has a first electrode wiring 21, a first pad 22, and a second pad 23. The first electrode wiring 21 is provided with a first electrode main wiring 211 and a plurality of first electrode sub-wirings 212. One end of the first electrode sub-wiring 212 is connected to the first electrode main wiring 211, and the other end is connected to the first pad 22 or the second pad 23. The first electrode sub-wiring 212 extends in the direction from the first electrode main wiring 211 toward the second electrode wiring 41.

[0086] (First Electrode Wiring) As shown in Figures 8 and 9, the first electrode wiring 21 is ladder-shaped. Specifically, the first electrode main wiring 211 and the first electrode sub-wiring 212 are formed by metal thin wires 210. The metal thin wires 210 consist of three parallel straight metal thin wires 210 arranged at intervals, and metal thin wires 210 that short-circuit adjacent parallel straight metal thin wires 210. A portion of the first electrode wiring 21 is surrounded by a first pad 22 and a loop portion 22c, which will be described later, when viewed from above.

[0087] (First Pad) The first pad 22 is a pad for mounting a light-emitting element (not shown). As shown in Figures 8 and 9, the first pad 22 is connected to the first electrode wiring 21. The first pad 22 is located between the first electrode wiring 21 and the second electrode wiring 41. As shown in Figure 2, the first pad 22 is provided with a first pad portion 22a and a first extraction portion 22b. The first pad portion 22a has the same structure as in Embodiment 1, so its description is omitted.

[0088] (First extraction section) The first extraction section 22b is a connection assist pattern for assisting the connection between the metal wire 210 and the pad. As shown in Figure 7A, the first extraction section 22b extends from the first pad section 22a. The first extraction section 22b connects to the first electrode wiring 21. The first extraction section 22b includes a loop section 22c that contacts the first pad 22 at least two points. A portion of the first electrode wiring 21 is surrounded by the first pad 22 and the loop section 22c in a top view.

[0089] Incidentally, the first electrode wiring 21 is formed in a ladder shape. According to the embodiment shown in Figures 8 and 9, the first electrode wiring 21 is connected to the first pad 22 via three points that are in close proximity to each other. Therefore, there is a concern that a sufficient path for heat transfer between the first electrode wiring 21 and the first pad 22 cannot be secured. Consequently, there is a concern that good quality soldering between the first electrode wiring 21 and the first pad 22 cannot be secured.

[0090] This configuration increases the number of contact points between the first electrode wiring 21 and the first pad 22. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60 less visible while maintaining electrical insulation between the first electrode wiring 21 and the second electrode wiring 41 and the dummy wiring 60, between the first pad 22 and the second pad 23 and the dummy wiring 60, and between the third pad 42 and the fourth pad 43 and the dummy wiring 60. Furthermore, it is possible to ensure sufficient heat transfer paths between the first electrode wiring 21 and the first pad 22.

[0091] (Second Pad) The second pad 23 is a pad for mounting a light-emitting element (not shown). Since the second pad 23 has the same structure as the first pad 22, its explanation will be omitted below.

[0092] (Second Electrode) As shown in Figures 8 and 9, the second electrode 40 is provided on the upper surface 10a of the base material 10 and is separated from the first electrode 20. The second electrode 40 has a second electrode wiring 41, a third pad 42, and a fourth pad 43. The second electrode wiring 41 is provided with a second electrode main wiring 411 and a plurality of second electrode sub-wirings 412. One end of the second electrode sub-wiring 412 is connected to the second electrode main wiring 411, and the other end is connected to the third pad 42 or the fourth pad 43. The second electrode sub-wiring 412 extends in the direction from the second electrode main wiring 411 toward the first electrode wiring 21.

[0093] (Second Electrode Wiring) As shown in Figures 8 and 9, the second electrode wiring 41 is ladder-shaped. Specifically, the second electrode main wiring 411 and the second electrode sub-wiring 412 are formed by metal nanowires 410. The metal nanowires 410 consist of three parallel straight metal nanowires 410 arranged at intervals, and metal nanowires 410 that short-circuit adjacent parallel straight metal nanowires 410.

[0094] (Third Pad) The third pad 42 is a pad for mounting a light-emitting element (not shown). As shown in Figures 8 and 9, the third pad 42 is connected to the second electrode wiring 41. The third pad 42 is located between the first electrode wiring 21 and the second electrode wiring 41. The third pad 42 is provided with a third pad portion 42a and a third extraction portion 42b.

[0095] (Third pad section) The third pad section 42a is a connection pattern for connecting a light-emitting element (not shown) and the second electrode wiring 41.

[0096] (Third extraction section) As shown in Figure 9, the third extraction section 42b includes a loop section 42c that contacts the third pad 42 at least two points. The third extraction section 42b is a connection assist pattern for assisting the connection between the metal wire 410 and the pad. The third extraction section 42b is located on the extension of the outer shape of the pad section and is formed in a loop shape.

[0097] (Fourth Pad) The fourth pad 43 is a pad for mounting a light-emitting element (not shown). Since the fourth pad 43 has the same structure as the third pad 42, its explanation will be omitted below.

[0098] (Dummy Wiring) As shown in Figure 8, the dummy wiring 60 is provided on the upper surface 10a of the base material 10 and is spaced apart from the first electrode 20 and the second electrode 40. The dummy wiring 60 is located between the first electrode wiring 21 and the second electrode wiring 41. The dummy wiring 60 is located between the first pad 22 and the second pad 23. The dummy wiring 60 is located between the third pad 42 and the fourth pad 43.

[0099] As shown in Figure 8, the dummy wiring 60 is ladder-shaped. Specifically, the dummy wiring 60 consists of thin metal wires 600 arranged in a ladder shape. The dummy wiring 60 is provided based on the direction in which the first electrode sub-wiring 212 and the second electrode sub-wiring 412 extend.

[0100] This configuration makes it possible to reduce the difference between the light aperture ratio of the portion of the light-transmitting substrate 1 where the first electrode wiring 21 and the second electrode wiring 41 are formed and the light aperture ratio of the portion where the first electrode wiring 21 and the second electrode wiring 41 are not formed. Furthermore, the dummy wiring 60 is electrically insulated from the first electrode wiring 21, the second electrode wiring 41, the first pad 22, the second pad 23, the third pad 42, and the fourth pad 43. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 difficult to see while maintaining electrical insulation between the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60, between the first pad 22, the second pad 23, and the dummy wiring 60, and between the third pad 42, the fourth pad 43, and the dummy wiring 60.

[0101] (Modification 5) Figure 10 shows a modification of Embodiment 2. Figure 10 shows the light-transmitting substrate 1 according to Modification 5. The light-transmitting substrate 1 according to Modification 5 differs from the light-transmitting substrate 1 according to Embodiment 2 in that dummy wiring 60 is provided based on the direction in which the first electrode main wiring 211 and the second electrode main wiring 411 extend. The other aspects are the same as those of Embodiment 2, so the explanation will be omitted.

[0102] (Dummy Wiring) As shown in Figure 10, the dummy wiring 60 is provided on the upper surface 10a of the base material 10 and is spaced apart from the first electrode 20 and the second electrode 40. The dummy wiring 60 is located between the first electrode wiring 21 and the second electrode wiring 41. The dummy wiring 60 is located between the first pad 22 and the second pad 23. The dummy wiring 60 is located between the third pad 42 and the fourth pad 43.

[0103] As shown in Figure 10, the dummy wiring 60 is ladder-shaped. Specifically, the dummy wiring 60 consists of thin metal wires 600 arranged in a ladder shape. The dummy wiring 60 is provided based on the direction in which the first electrode main wiring 211 and the second electrode main wiring 411 extend.

[0104] This configuration makes it possible to reduce the difference between the light aperture ratio of the portion of the light-transmitting substrate 1 where the first electrode wiring 21 and the second electrode wiring 41 are formed and the light aperture ratio of the portion where the first electrode wiring 21 and the second electrode wiring 41 are not formed. Furthermore, the dummy wiring 60 is electrically insulated from the first electrode wiring 21, the second electrode wiring 41, the first pad 22, the second pad 23, the third pad 42, and the fourth pad 43. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 difficult to see while maintaining electrical insulation between the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60, between the first pad 22, the second pad 23, and the dummy wiring 60, and between the third pad 42, the fourth pad 43, and the dummy wiring 60.

[0105] [Summary] As described above, the first disclosure is a light-transmitting substrate 1, comprising a transparent resin material base 10, a first electrode 20 provided on the upper surface 10a of the base 10, a second electrode 40 provided on the upper surface 10a of the base 10 and spaced apart from the first electrode 20, and a mesh-like dummy wiring 60 provided on the upper surface 10a of the base 10 and spaced apart from the first electrode 20 and the second electrode 40. The first electrode 20 has a mesh-like first electrode wiring 21, a first pad 22 connected to the first electrode wiring 21, and a second pad 23 connected to the first electrode wiring 21 and connected in parallel with the first pad 22. The second electrode 40 has a mesh-like second electrode wiring 41, a third pad 42 connected to the second electrode wiring 41 and spaced apart from the first pad 22, and a fourth pad 43 connected to the second electrode wiring 41 and connected in parallel with the third pad 42. The dummy wiring 60 is located between the first electrode wiring 21 and the second electrode wiring 41. The dummy wiring 60 is located between the first pad 22 and the second pad 23. The dummy wiring 60 is located between the third pad 42 and the fourth pad 43.

[0106] Incidentally, in the light-transmitting substrate 1, a difference in the aperture ratio of light occurs between the parts where the first electrode wiring 21 and the second electrode wiring 41 are formed and the parts where they are not. Therefore, there is a difference in appearance between the parts where the first electrode wiring 21 and the second electrode wiring 41 are formed and the parts where they are not. As a result, the parts where the first electrode wiring 21 and the second electrode wiring 41 are formed or not formed become more easily visible.

[0107] According to the first disclosure, the light-transmitting substrate 1 includes a mesh-like dummy wiring 60 that is separated from the first electrode 20 and the second electrode 40. The dummy wiring 60 is located between the first electrode wiring 21 and the second electrode wiring 41. The dummy wiring 60 is located between the first pad 22 and the second pad 23. The dummy wiring 60 is located between the third pad 42 and the fourth pad 43. Therefore, in the light-transmitting substrate 1, the difference between the light aperture ratio of the portion where the first electrode wiring 21 and the second electrode wiring 41 are formed and the light aperture ratio of the portion where the first electrode wiring 21 and the second electrode wiring 41 are not formed can be reduced. Furthermore, the dummy wiring 60 is electrically insulated from the first electrode wiring 21, the second electrode wiring 41, the first pad 22, the second pad 23, the third pad 42, and the fourth pad 43. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 difficult to see while maintaining electrical insulation between the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60, between the first pad 22, the second pad 23, and the dummy wiring 60, and between the third pad 42, the fourth pad 43, and the dummy wiring 60.

[0108] The second disclosure states that, in the first disclosure, the aperture ratio of the dummy wiring 60 is equal to the aperture ratio of the first electrode wiring 21. The aperture ratio of the dummy wiring 60 is equal to the aperture ratio of the second electrode wiring 41.

[0109] According to the second disclosure, in the light-transmitting substrate 1, the difference between the light aperture ratio of the portion where the first electrode wiring 21 and the second electrode wiring 41 are formed and the light aperture ratio of the portion where the first electrode wiring 21 and the second electrode wiring 41 are not formed can be reduced. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60 less visible while maintaining electrical insulation between the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60, between the first pad 22, the second pad 23 and the dummy wiring 60, and between the third pad 42, the fourth pad 43 and the dummy wiring 60.

[0110] The third disclosure relates to the dummy wiring 60 in the first disclosure, which includes a first end 60a located closest to the first electrode 20 and a second end 60b located closest to the second electrode 40. The dummy wiring 60 is insulated between the first end 60a and the second end 60b.

[0111] According to the third disclosure, the dummy wiring 60 is insulated between its first end 60a and its second end 60b. Therefore, it is possible to prevent the first electrode wiring 21 and the second electrode wiring 41 from becoming electrically connected by the dummy wiring 60. This makes it possible to maintain electrical insulation between the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 while making the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 difficult to see.

[0112] The fourth disclosure is that, in the first disclosure, the dummy wiring 60 includes a third end 60d located closest to the third pad 42 and a fourth end 60e located closest to the second pad 23. The dummy wiring 60 is insulated between the third end 60d and the fourth end 60e.

[0113] According to the fourth disclosure, the dummy wiring 60 is insulated between the third end 60d and the fourth end 60e. Therefore, it is possible to prevent the second pad 23 and the third pad 42 from becoming electrically connected by the dummy wiring 60. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 less visible while maintaining electrical insulation between the second pad 23, the third pad 42, and the dummy wiring 60.

[0114] The fifth disclosure further includes, in the first disclosure, a dummy wiring 60 comprising a rectangular first cell 650 having a first vertex 65a and a cut first side 65b, and a rectangular second cell 660 having the first vertex 65a as its vertex and a cut second side 66b. The position of the first side 65b in the first cell 650 is different from the position of the second side 66b in the second cell 660.

[0115] According to the fifth disclosure, the position of the first side 65b in the first cell 650 is different from the position of the second side 66b in the second cell 660. That is, in the first cell 650 and the second cell 660, which are adjacent and share a first vertex 65a, if the first cell 650 is shifted parallel to the position of the second cell 660 and superimposed, the cut first side 65b of the first cell 650 does not overlap with the cut second side 66b of the second cell 660. Therefore, the cuts provided in the dummy wiring 60 are irregularly arranged and become less noticeable. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60 less visible while maintaining electrical insulation between the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60, between the first pad 22, the second pad 23 and the dummy wiring 60, and between the third pad 42 and the fourth pad 43 and the dummy wiring 60.

[0116] The sixth disclosure states that, in the first disclosure, the first pad 22 and the second pad 23 are located between the first electrode wiring 21 and the second electrode wiring 41. The third pad 42 and the fourth pad 43 are located between the first electrode wiring 21 and the second electrode wiring 41.

[0117] According to the sixth disclosure, the first pad 22, second pad 23, third pad 42, and fourth pad 43 are located between the first electrode wiring 21 and the second electrode wiring 41. That is, the first pad 22 and the second pad 23 are arranged on the edge of the first electrode wiring 21 facing the second electrode wiring 41, so as to protrude from the first electrode wiring 21 toward the second electrode wiring 41. On the other hand, the third pad 42 and the fourth pad 43 are arranged on the edge of the second electrode wiring 41 facing the first electrode wiring 21, so as to protrude from the second electrode wiring 41 toward the first electrode wiring 21. Therefore, since the first pad 22, second pad 23, third pad 42, and fourth pad 43 are arranged between the first electrode wiring 21 and the second electrode wiring 41, the distance between the first electrode wiring 21 and the second electrode wiring 41 can be increased. In other words, the area of ​​the dummy wiring 60 can be increased. In addition, the insulation between the first electrode wiring 21 and the second electrode wiring 41 can be improved.

[0118] This makes it possible to make the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60 difficult to see while maintaining electrical insulation between the first electrode wiring 21, the second electrode wiring 41, and the dummy wiring 60, between the first pad 22, the second pad 23, and the dummy wiring 60, and between the third pad 42, the fourth pad 43, and the dummy wiring 60.

[0119] The seventh disclosure is that, in the first disclosure, the first pad 22 comprises a first pad portion 22a and a first extraction portion 22b extending from the first pad portion 22a. The third pad 42 comprises a third pad portion 42a and a third extraction portion 42b extending from the third pad portion 42a. The first extraction portion 22b is connected to the first electrode wiring 21. The third extraction portion 42b is connected to the second electrode wiring 41.

[0120] Incidentally, the first electrode wiring 21 is formed in a mesh shape. The edge of the first electrode wiring 21 facing the second electrode wiring 41 is in a state where the mesh is cut at an arbitrary position. In other words, the ends of the metal fine wires 210 are arranged at arbitrary intervals along the edge of the first electrode wiring 21. On the other hand, the first pad 22 is provided at the edge of the area where the first electrode wiring 21 is installed. At this time, it is not possible to guarantee the number of ends of the metal fine wires 210 that contact the first pad 22, or where the ends of the metal fine wires 210 contact the first pad 22. Therefore, there is a concern that the way heat is transferred between the first electrode wiring 21 and the first pad 22, or between the first electrode wiring 21 and the second pad 23, may differ greatly, leading to large variations in the quality of soldering between the first electrode wiring 21 and the first pad 22.

[0121] Furthermore, the same effects and advantages described above can also be achieved between the second electrode wiring 41 and the third pad 42.

[0122] According to the seventh disclosure, the first pad 22 is reliably connected to the mesh-like first electrode wiring 21 regardless of the position of the end of the metal wire 210. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60 difficult to see while maintaining electrical insulation between the first electrode wiring 21 and the second electrode wiring 41 and the dummy wiring 60, between the first pad 22 and the second pad 23 and the dummy wiring 60, and between the third pad 42 and the fourth pad 43 and the dummy wiring 60. Furthermore, it is possible to reduce variations in the way heat is transferred between the first electrode wiring 21 and the first pad 22, thereby reducing variations in solder quality.

[0123] The eighth disclosure states that, in the seventh disclosure, the first pad portion 22a is physically connected to the first electrode wiring 21. The third pad portion 42a is physically connected to the second electrode wiring 41.

[0124] According to the eighth disclosure, the number of contact points between the first electrode wiring 21 and the first pad 22 can be increased. In other words, sufficient paths for heat transfer can be secured between the first electrode wiring 21 and the first pad 22. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60 less visible while maintaining electrical insulation between the first electrode wiring 21 and the second electrode wiring 41 and the dummy wiring 60, between the first pad 22 and the second pad 23 and the dummy wiring 60, and between the third pad 42 and the fourth pad 43 and the dummy wiring 60. Furthermore, sufficient paths for heat transfer can be secured between the first electrode wiring 21 and the first pad 22.

[0125] Furthermore, the same effects and advantages described above can also be achieved between the second electrode wiring 41 and the third pad 42.

[0126] Furthermore, the ninth disclosure is a light-transmitting substrate 1 comprising a transparent resin material base 10, a first electrode 20 provided on the upper surface 10a of the base 10, a second electrode 40 provided on the upper surface 10a of the base 10 and spaced apart from the first electrode 20, and a ladder-shaped dummy wiring 60 provided on the upper surface 10a of the base 10 and spaced apart from the first electrode 20 and the second electrode 40. The first electrode 20 has a ladder-shaped first electrode wiring 21, a first pad 22 connected to the first electrode wiring 21, and a second pad 23 connected to the first electrode wiring 21 and connected in parallel with the first pad 22. The second electrode 40 has a ladder-shaped second electrode wiring 41, a third pad 42 connected to the second electrode wiring 41 and spaced apart from the first pad 22, and a fourth pad 43 connected to the second electrode wiring 41 and connected in parallel with the third pad 42. The dummy wiring 60 is located between the first electrode wiring 21 and the second electrode wiring 41. The dummy wiring 60 is located between the first pad 22 and the second pad 23. The dummy wiring 60 is located between the third pad 42 and the fourth pad 43.

[0127] Incidentally, in the light-transmitting substrate 1, a difference in the aperture ratio of light occurs between the parts where the first electrode wiring 21 and the second electrode wiring 41 are formed and the parts where they are not. Therefore, there is a difference in appearance between the parts where the first electrode wiring 21 and the second electrode wiring 41 are formed and the parts where they are not. As a result, the parts where the first electrode wiring 21 and the second electrode wiring 41 are formed or not formed become more easily visible.

[0128] According to the ninth disclosure, the light-transmitting substrate 1 includes ladder-shaped dummy wiring 60 that is separated from the first electrode 20 and the second electrode 40. The first electrode 20 has ladder-shaped first electrode wiring 21. The second electrode 40 has ladder-shaped second electrode wiring 41. Therefore, in the light-transmitting substrate 1, the difference between the light aperture ratio of the portion where the first electrode wiring 21 and the second electrode wiring 41 are formed and the light aperture ratio of the portion where the first electrode wiring 21 and the second electrode wiring 41 are not formed can be reduced. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60 difficult to see while maintaining electrical insulation between the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60, between the first pad 22, the second pad 23 and the dummy wiring 60, and between the third pad 42, the fourth pad 43 and the dummy wiring 60.

[0129] The tenth disclosure, in the ninth disclosure, includes a loop portion 22c that contacts the first pad 22 at at least two points. A portion of the first electrode wiring 21 is surrounded by the first pad 22 and the loop portion 22c in a top view.

[0130] Incidentally, the first electrode wiring 21 is formed in a ladder shape. According to the embodiment shown in Figure 10, the first electrode wiring 21 is connected to the first pad 22 via three points that are in close proximity to each other. Therefore, there is a concern that a sufficient path for heat transfer between the first electrode wiring 21 and the first pad 22 cannot be secured. Consequently, there is a concern that good quality soldering between the first electrode wiring 21 and the first pad 22 cannot be secured.

[0131] According to the tenth disclosure, the number of contact points between the first electrode wiring 21 and the first pad 22 can be increased. This ensures sufficient heat transfer paths between the first electrode wiring 21 and the first pad 22. This makes it possible to make the first electrode wiring 21, the second electrode wiring 41 and the dummy wiring 60 less visible while maintaining electrical insulation between the first electrode wiring 21 and the second electrode wiring 41 and the dummy wiring 60, between the first pad 22 and the second pad 23 and the dummy wiring 60, and between the third pad 42 and the fourth pad 43 and the dummy wiring 60. Furthermore, it ensures sufficient heat transfer paths between the first electrode wiring 21 and the first pad 22.

[0132] As described above, this disclosure is industrially applicable as a light-transmitting substrate.

[0133] 1: Light-transmitting substrate 10: Base material 20: First electrode 21: First electrode wiring 22: First pad 22a: First pad section 22b: First extraction section 22c: Loop section 23: Second pad 30: First signal wiring 40: Second electrode 41: Second electrode wiring 42: Third pad 43: Fourth pad 50: Second signal wiring 60: Dummy wiring 60a: First end 60b: Second end 60d: Third end 60e: Fourth end 65: First cell 65a: First vertex 65b: First edge 66: Second cell 66b: Second edge

Claims

1. A light-transmitting substrate comprising: a transparent resin material substrate; a first electrode provided on the upper surface of the substrate; a second electrode provided on the upper surface of the substrate and spaced apart from the first electrode; and a mesh-like dummy wiring provided on the upper surface of the substrate and spaced apart from the first electrode and the second electrode, wherein the first electrode has a mesh-like first electrode wiring; a first pad connected to the first electrode wiring; and a second pad connected to the first electrode wiring and in parallel with the first pad; the second electrode has a mesh-like second electrode wiring; a third pad connected to the second electrode wiring and spaced apart from the first pad; and a fourth pad connected to the second electrode wiring and in parallel with the third pad; the dummy wiring is located between the first electrode wiring and the second electrode wiring; the dummy wiring is located between the first pad and the second pad; and the dummy wiring is located between the third pad and the fourth pad.

2. The light-transmitting substrate according to claim 1, wherein the aperture ratio of the dummy wiring is equal to the aperture ratio of the first electrode wiring, and the aperture ratio of the dummy wiring is equal to the aperture ratio of the second electrode wiring.

3. The light-transmitting substrate according to claim 1, wherein the dummy wiring includes a first end located closest to the first electrode and a second end located closest to the second electrode, and the dummy wiring is insulated between the first end and the second end.

4. The light-transmitting substrate according to claim 1, wherein the dummy wiring includes a third end located closest to the third pad and a fourth end located closest to the second pad, and the dummy wiring is insulated between the third end and the fourth end.

5. The light-transmitting substrate according to claim 1, wherein the dummy wiring further comprises a rectangular first cell having a first vertex and a cut first edge, and a rectangular second cell having the first vertex as its vertex and including a cut second edge, wherein the position of the first edge in the first cell is different from the position of the second edge in the second cell.

6. The light-transmitting substrate according to claim 1, wherein the first pad and the second pad are located between the first electrode wiring and the second electrode wiring, and the third pad and the fourth pad are located between the first electrode wiring and the second electrode wiring.

7. The light-transmitting substrate according to claim 1, wherein the first pad comprises a first pad portion and a first extraction portion extending from the first pad portion, the third pad comprises a third pad portion and a third extraction portion extending from the third pad portion, the first extraction portion is connected to the first electrode wiring, and the third extraction portion is connected to the second electrode wiring.

8. The light-transmitting substrate according to claim 7, wherein the first pad portion is physically connected to the first electrode wiring, and the third pad portion is physically connected to the second electrode wiring.

9. A light-transmitting substrate comprising: a transparent resin material substrate; a first electrode provided on the upper surface of the substrate; a second electrode provided on the upper surface of the substrate and spaced apart from the first electrode; and a ladder-shaped dummy wiring provided on the upper surface of the substrate and spaced apart from the first electrode and the second electrode, wherein the first electrode has: a ladder-shaped first electrode wiring; a first pad connected to the first electrode wiring; a second pad connected to the first electrode wiring and connected in parallel with the first pad; the second electrode has: a ladder-shaped second electrode wiring; a third pad connected to the second electrode wiring and spaced apart from the first pad; a fourth pad connected to the second electrode wiring and connected in parallel with the third pad; the dummy wiring is located between the first electrode wiring and the second electrode wiring; the dummy wiring is located between the first pad and the second pad; and the dummy wiring is located between the third pad and the fourth pad.

10. The light-transmitting substrate according to claim 9, wherein the first extraction portion includes a loop portion that contacts the first pad at least in two places, and a portion of the first electrode wiring is surrounded by the first pad and the loop portion in a top view.

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