Touch panel
The touch panel design with laminated conductive layers and mesh patterns addresses the challenge of narrowing the peripheral area by efficiently connecting electrodes and wirings, resulting in a narrower frame and improved sensitivity.
Patent Information
- Application Number
- JP2023092437
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-06-05
- Publication Date
- 2024-12-17
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing touch panels face challenges in narrowing the peripheral area outside the touch area due to the need for space to arrange multiple wirings, which complicates frame narrowing and can lead to increased electrical resistance and decreased detection sensitivity.
A touch panel design with a laminated structure of first and second conductive layers, incorporating first and second detection electrodes, dummy electrodes, and connection parts that penetrate the insulating layer, forming mesh patterns to connect electrodes and wirings, allowing for a narrower peripheral area and improved sensitivity.
The design enables a narrower frame with reduced electrical resistance and enhanced detection sensitivity by connecting electrodes and wirings efficiently, maintaining electrical connection reliability even with potential cracks or disconnections.
Smart Images

Figure 2024174553000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to a touch panel that detects a touch operation. [Background technology]
[0002] 2. Description of the Related Art Conventionally, in various electronic devices including tablet computers, smartphones, and other portable information devices, touch panels are used that detect a so-called touch operation in which a finger, a stylus pen, or the like is brought into contact with or close to a screen.
[0003] In such touch panels, as disclosed in Patent Document 1, for example, a plurality of first detection electrodes extending along a first direction and arranged in a second direction perpendicular to the first direction, and a plurality of second detection electrodes extending along the second direction and arranged in the first direction are often arranged so as to overlap each other on an insulating layer, and a plurality of first wirings are drawn out from the first direction ends of the plurality of first detection electrodes, and a plurality of second wirings are drawn out from the second direction ends of the plurality of second detection electrodes. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] Patent Publication No. 2021-157421 Summary of the Invention [Problem to be solved by the invention]
[0005] Meanwhile, there is an increasing demand for narrowing the peripheral area of a touch panel that is located outside the touch area and is not used for touch detection, that is, narrowing the so-called frame. When drawing out a plurality of first wirings and a plurality of second wirings from the ends of a plurality of first detection electrodes in the first direction and the ends of a plurality of second detection electrodes in the second direction, as in the touch panel disclosed in Patent Document 1, it is necessary to secure an area on the insulating layer for arranging the plurality of first wirings and the plurality of second wirings drawn out in both the first direction and the second direction, so that it may be difficult to narrow the frame beyond a certain level.
[0006] The present invention has been made to solve such problems, and has an object to provide a touch panel that can narrow the peripheral area not used for touch detection. [Means for solving the problem]
[0007] The above object can be achieved by the following configuration. [1] A touch panel having a touch area and a peripheral area outside the touch area, a first conductive layer made of a first thin metal wire, an insulating layer, and a second conductive layer made of a second thin metal wire are laminated in this order; the first conductive layer is formed in the touch area and has a plurality of first detection electrodes extending along a first direction and arranged in a second direction perpendicular to the first direction, a plurality of first dummy electrodes arranged between the plurality of first detection electrodes and insulated from the plurality of first detection electrodes, a plurality of first wirings formed in the peripheral area and connected to the plurality of first detection electrodes, and a plurality of second wirings arranged on the plurality of first dummy electrodes; the second conductive layer is formed in the touch area and has a plurality of second detection electrodes extending along the second direction and arranged in the first direction; a plurality of connection portions that penetrate the insulating layer and connect the plurality of second detection electrodes and the plurality of second wirings to each other; In plan view, the first detection electrodes have a first mesh pattern formed by a first thin metal wire; the second detection electrodes have a second mesh pattern formed by second thin metal wires; In the touch area, the first mesh pattern and the second mesh pattern are combined with each other in a plan view to form a third mesh pattern; the second wirings correspond to the second detection electrodes; The corresponding second wiring and second detection electrodes are connected to each other by two or more connection parts. Touch panel. [2] The plurality of second wirings and the corresponding plurality of second detection electrodes are connected to each other by three or more connection parts. The touch panel described in [1]. [3] The connection parts are arranged at the intersections of the second mesh pattern. The touch panel according to [1] or [2]. [4] The first dummy electrode has a first mesh pattern in a plan view, The connection portion is disposed at an intersection portion between the first mesh pattern and the second mesh pattern in a plan view. The touch panel according to [1] or [2]. [5] The connection portion is made of a conductive material different from the conductive material that constitutes the second detection electrode and the second wiring. The touch panel according to any one of [1] to [4]. [6] The conductive material of the connection part is a transparent conductive material. The touch panel according to [5]. [7] The first dummy electrode has a first mesh pattern in a plan view, The second wiring constitutes a part of the first mesh pattern in a plan view. The touch panel according to any one of [1] to [6]. [8] The first dummy electrode has a first ground wiring that is disposed between the first detection electrode and the second wiring and is insulated from the first detection electrode and the second wiring; The first ground wiring constitutes a part of the first mesh pattern. The touch panel according to any one of [1] to [7]. [9] The first thin metal wire has at least two or more breaks adjacent to each other in an extending direction of the first thin metal wire between the second wiring and the first detection electrode adjacent to the second wiring. The touch panel according to any one of [1] to [8].
[10] The first thin metal wire has at least two or more breaks adjacent to each other in an extending direction of the first thin metal wire between the first ground wiring and the first detection electrode adjacent to the first ground wiring, and between the first ground wiring and the second wiring adjacent to the first ground wiring. The touch panel according to [8].
[11] The thickness of the insulating layer is 0.5 μm or more and 5.0 μm or less. The touch panel according to any one of [1] to
[10] . Effect of the Invention
[0008] According to this invention, a touch panel has a configuration in which a first conductive layer made of a first thin metal wire, an insulating layer, and a second conductive layer made of a second thin metal wire are sequentially laminated, the first conductive layer having a plurality of first detection electrodes formed in a touch area and extending along a first direction and arranged in a second direction perpendicular to the first direction, a plurality of first dummy electrodes arranged between the plurality of first detection electrodes and insulated from the plurality of first detection electrodes, a plurality of first wirings formed in a peripheral area and connected to the plurality of first detection electrodes, and a plurality of second wirings arranged on the plurality of first dummy electrodes, the second conductive layer having a plurality of second detection electrodes formed in the touch area and extending along the second direction and arranged in the first direction, and a plurality of second wirings formed on the plurality of first dummy electrodes. The touch panel has a plurality of connection parts connecting a plurality of second detection electrodes and a plurality of second wirings to each other, and in a planar view, the plurality of first detection electrodes have a first mesh pattern formed by a first thin metal wire, and the plurality of second detection electrodes have a second mesh pattern formed by a second thin metal wire, and in the touch area, the first mesh pattern and the second mesh pattern are combined with each other in a planar view to form a third mesh pattern, and the plurality of second wirings correspond to the plurality of second detection electrodes, and the corresponding second wirings and the plurality of second detection electrodes are connected to each other by two or more connection parts, so that it is possible to narrow the peripheral area not used for touch detection, and a touch panel with high yield and high sensitivity can be provided. [Brief description of the drawings]
[0009] [Figure 1] 1 is a partial cross-sectional view of a touch panel according to a first embodiment. [Diagram 2] FIG. 1 is a plan view of a touch panel according to a first embodiment. [Diagram 3] 2 is an enlarged partial cross-sectional view showing an opening formed in an insulating layer in the first embodiment. FIG. [Figure 4] 2 is an enlarged plan view showing a part of a first conductive layer in the first embodiment. FIG. [Diagram 5] 4 is an enlarged plan view showing a part of a first dummy electrode in the first embodiment. FIG. [Figure 6]4 is an enlarged plan view showing a part of a second conductive layer in the first embodiment. FIG. [Figure 7] 2 is an enlarged plan view showing a part of a touch area in the first embodiment. FIG. [Figure 8] 11 is an enlarged plan view showing a part of a first conductive layer in the second embodiment. FIG. [Figure 9] 13 is an enlarged plan view showing a part of a touch region in the second embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a conductive member for a touch panel and a touch panel according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings. In the following, the notation "~" indicating a numerical range includes the numerical values written on both sides. For example, "s is a number between t1 and t2" means that the range of s includes the numerical values t1 and t2, which is expressed in mathematical notation as t1≦s≦t2. Unless otherwise specified, angles including "perpendicular" and "parallel" include a generally acceptable error range in the technical field. "Transparent" means that the light transmittance is at least 40% or more in the visible light wavelength range of 400 nm to 800 nm, preferably 75% or more, more preferably 80% or more, and even more preferably 90% or more. The light transmittance is measured according to "Plastics--Determination of total light transmittance and total light reflectance" as specified in JIS K 7375:2008.
[0011] First embodiment FIG. 1 shows a configuration of a touch panel in accordance with a first embodiment of the present invention. The touch panel includes an insulating layer 1 having a first surface 1A and a second surface 1B that form a front and a back surface of each other, a first conductive layer 2A disposed on the first surface 1A of the insulating layer 1, and a second conductive layer 2B disposed on the second surface 1B of the insulating layer 1. The insulating layer 1 is made of a transparent material.
[0012] The touch panel can be used as a touch panel display device (not shown) by disposing a cover member (not shown) on the surface on the first conductive layer 2A side and attaching a display module (not shown) to the surface on the second conductive layer 2B side. At this time, a user's finger, stylus pen, or the like in contact with or close to the cover member is detected, and a touch operation by the user is detected.
[0013] 2 shows a plan view of the touch panel. The first conductive layer 2A extends along a defined Y direction (first direction) and is arranged along an X direction (second direction) perpendicular to the Y direction, and has a plurality of first detection electrodes 11 for detecting a touch operation arranged in a touch region R1, first wirings 12 arranged in a peripheral region R2 outside the touch region R1 and drawn from one end of the plurality of first detection electrodes 11 in the Y direction, and a plurality of first electrode pads 13 connected to the plurality of first wirings 12. The plurality of first electrode pads 13 are used for electrical connection to a touch panel driving device (not shown).
[0014] The first conductive layer 2A has a plurality of first dummy electrodes 14 arranged between the plurality of first detection electrodes 11, extending along the Y direction, arranged in the X direction, and arranged in the touch region R1. The plurality of first dummy electrodes 14 are electrically insulated from the plurality of first detection electrodes 11.
[0015] The first conductive layer 2A also has a plurality of second wirings 22 respectively arranged in the plurality of first dummy electrodes 14, and a plurality of second electrode pads 23 arranged in a peripheral region R2 outside the touch region R1 and connected to the plurality of second wirings 22. As will be described later, the plurality of second wirings 22 are connected to the second detection electrodes 21 of the second conductive layer 2B via openings, i.e., so-called through holes, formed in the insulating layer 1. The plurality of second electrode pads 23, like the plurality of first electrode pads 13, are used for electrical connection to a touch panel driving device (not shown).
[0016] The second conductive layer 2B has a plurality of second detection electrodes 21 extending along the X direction, arranged along the Y direction, and disposed in the touch region R1 for detecting a touch operation. The second conductive layer 2B may also have a plurality of second dummy electrodes 24 disposed between the plurality of second detection electrodes 21, extending along the X direction, and arranged in the Y direction. The plurality of second dummy electrodes 24 are electrically insulated from the plurality of second detection electrodes 21.
[0017] The touch panel has a touch area R1 where a plurality of first detection electrodes 11 and a plurality of second detection electrodes 21 are arranged to overlap each other and detect a touch operation by a user, and a peripheral area R2 outside the touch area R1. The peripheral area R2 is an area extending to one end side of the touch area R1 in the Y direction, and a plurality of first wirings 12, a plurality of first electrode pads 13, some of the plurality of second wirings 22, and a plurality of second electrode pads 23 are arranged in the peripheral area R2.
[0018] 3, the insulating layer 1 has a plurality of openings H and a plurality of connection parts 31 formed in the plurality of openings H to penetrate the insulating layer 1 and electrically connect the plurality of second detection electrodes 21 and the plurality of second wirings 22 to each other. The form of the connection parts 31 is not particularly limited, but for example, the connection parts 31 can be formed by a conductor filling the openings H as shown in FIG. 3. The connection parts 31 can also be formed by a conductive layer formed on the inner wall of the openings H.
[0019] Generally, in a touch panel, a plurality of first wirings 12 and a plurality of second wirings 22 are often drawn out from one end in the Y direction of the plurality of first detection electrodes 11 and one end in the X direction of the plurality of second detection electrodes 21, respectively. In recent years, there has been an increasing demand for narrowing the peripheral region R2 not used for touch detection, that is, narrowing the frame. In this case, however, it is necessary to secure an area on the insulating layer 1 for arranging the plurality of first wirings 12 and the plurality of second wirings 22 at least on both one end side in the Y direction and one end side in the X direction of the touch region R1, and it may be difficult to narrow the frame beyond a certain limit.
[0020] In the touch panel of embodiment 1, the second detection electrode 21 is connected to the second wiring 22 arranged in the first dummy electrode 14 by multiple connection parts 31 through multiple openings H formed in the insulating layer 1, so there is no need to secure a peripheral area R2 on the insulating layer 1 outside the touch area R1 in the X direction, and the peripheral area R2 not used for touch detection can be narrowed.
[0021] Generally, to facilitate connection of a touch panel drive device to a touch panel, terminals of the multiple first wirings 12 and terminals of the multiple second wirings 22 are often concentrated at one end of the insulating layer 1. In this case, it is usually necessary to arrange the multiple first wirings 12 or the multiple second wirings 22 along the periphery of the touch region R1, and therefore, as the multiple first wirings 12 or the multiple second wirings 22 become longer, the electrical resistance also increases, and there are cases in which the detection sensitivity for touch operations decreases.
[0022] In the touch panel of embodiment 1, the second detection electrode 21 is connected to the second wirings 22 arranged in the first dummy electrode 14 by multiple connection parts 31 through multiple openings H formed in the insulating layer 1, so that the multiple first wirings 12 and the multiple second wirings 22 can be pulled out in the same direction and the multiple first wirings 12 and the multiple second wirings 22 can be made relatively short, reducing the electrical resistance and improving the detection sensitivity for touch operations.
[0023] Here, if the thickness of the insulating layer 1 is less than 0.5 μm, there may be a high risk of poor continuity in the connection part 31 if cracks or breaks occur in the connection part 31 due to deformation of the insulating layer 1 or the like. Also, if the thickness of the insulating layer 1 is greater than 5.0 μm, there may be a high risk of poor continuity in the connection part 31 if the connection part 31 is not formed normally. Therefore, the thickness of the insulating layer 1 is preferably 0.5 μm or more and 5.0 μm or less.
[0024] Moreover, in order to improve the conductivity between the second detection electrode 21 and the second wiring 22, the connection portion 31 is preferably made of a conductive material different from the conductive material that constitutes the second detection electrode 21 and the second wiring 22. Furthermore, the connection portion 31 is preferably made of a transparent conductive material in order to make the connection portion 31 less visible to the user. By using a transparent conductive material for the connection portion 31, there is no effect on visibility, i.e., the connection portion 31 becomes less noticeable, so that the opening H of the insulating layer 1 can be made larger.
[0025] 4 shows a partially enlarged plan view of the first conductive layer 2A. The first detection electrodes 11 and the first dummy electrodes 14 have a first mesh pattern P1 formed by first thin metal wires A1 in plan view. The first mesh pattern P1 is composed of a plurality of diamond-shaped first basic mesh cells C1 formed by four sides extending along a first extension direction D1 and a second extension direction D2 that are different from the X and Y directions. It should be noted that the mesh pattern in the present invention does not necessarily have to be a continuous line made of thin metal wires, and may be a pattern having discontinuous parts (disconnected parts) in the mesh pattern.
[0026] The second wiring 22 forms a mesh-like second wiring pattern M1 configured by connecting a plurality of first basic mesh cells C1, and constitutes a part of the first mesh pattern P1 within the first dummy electrode .
[0027] 4, an opening H is located on each of the four sides of one first basic mesh cell C1 of the second wiring pattern M1, and one corresponding second wiring 22 and one corresponding second detection electrode 21 are electrically connected to each other by four connection parts 31 formed in the four opening parts H. In this way, in the touch panel of the first embodiment, the corresponding second wiring 22 and second detection electrode 21 are connected to each other by two or more connection parts 31. Therefore, even if a crack or break occurs in any of the multiple connection parts 31 for some reason, the electrical connection between the second wiring 22 and the second detection electrode 21 can be maintained.
[0028] The greater the number of connection parts 31 connecting the corresponding second wirings 22 and second detection electrodes 21, the more reliable the electrical connection between the second wirings 22 and the second detection electrodes 21. In order to obtain excellent reliability of the electrical connection between the second wirings 22 and the corresponding second detection electrodes 21, it is preferable to connect the second wirings 22 and the second detection electrodes 21 by three or more connection parts 31, for example.
[0029] 4, the first dummy electrode 14 has a first ground wiring G1 that is disposed between the first detection electrode 11 and the second wiring 22 and is insulated from the first detection electrode 11 and the second wiring 22. The first ground wiring G1 has a function of a so-called electromagnetic shield that prevents electrical interference between an electrical signal conducted through the second wiring 22 and an electrical signal in the first detection electrode 11. Therefore, the first ground wiring G1 can prevent erroneous detection of a touch operation caused by electrical interference and improve detection sensitivity for a touch operation.
[0030] The first ground wiring G1 forms a mesh-shaped ground wiring pattern M2 composed of a plurality of first basic mesh cells C1. This makes it possible to electromagnetically shield the first detection electrode 11 and the second wiring 22 even if a break occurs in a part of the first ground wiring G1.
[0031] 5, the first fine metal wire A1 has at least two or more disconnected parts B adjacent to each other in the direction in which the first fine metal wire A1 extends, i.e., in the first extension direction D1 and the second extension direction D2, between the second wiring 22 and the first detection electrode 11 adjacent to the second wiring 22. This makes it possible to more reliably ensure electrical insulation between the first detection electrode 11 and the second wiring 22.
[0032] Furthermore, the first thin metal wire A1 has at least two or more disconnection parts B adjacent to each other in the first extension direction D1 and the second extension direction D2 between the first ground wiring G1 and the first detection electrode 11 adjacent to the first ground wiring G1, and between the first ground wiring G1 and the second wiring 22 adjacent to the first ground wiring G1, respectively. This makes it possible to more reliably ensure electrical insulation between the first detection electrode 11 and the first ground wiring G1, and between the second wiring 22 and the first ground wiring G1.
[0033] FIG. 6 shows a plan view of an enlarged portion of the second conductive layer 2B. The second detection electrodes 21 and the second dummy electrodes 24 have a second mesh pattern P2 formed by the second metal thin wires A2 in a plan view. The second mesh pattern P2 is composed of a plurality of diamond-shaped second basic mesh cells C2 formed by four sides extending along the first extension direction D1 and the second extension direction D2. Here, the second metal thin wires A2 can be composed of the same conductive material as the first metal thin wires A1. The second basic mesh cells C2 may be the same as or different from the first basic mesh cells C1, but it is preferable that the second basic mesh cells C2 have the same shape and size (area) as the first basic mesh cells C1 in order to form a third mesh pattern in which mesh cells are regularly arranged by overlapping the first conductive layer 2A and the second conductive layer 2B, as described later.
[0034] FIG. 7 shows a plan view of an enlarged portion of the touch area R1 in the touch panel. In the touch area R1, the first metal wires A1 of the first conductive layer 2A and the second metal wires A2 of the second conductive layer 2B are combined with each other in a plan view to form the third mesh pattern P3. In the example of FIG. 7, the first basic mesh cell C1 constituting the first mesh pattern P1 and the second basic mesh cell C2 constituting the second mesh pattern P2 have the same shape and size, and the first mesh pattern P1 and the second mesh pattern P2 are shifted from each other in the X direction by half the width of the first basic mesh cell C1 and the second basic mesh cell C2 (half the pitch of the first basic mesh cell C1 and the second basic mesh cell C2). Therefore, the third mesh pattern P3 is composed of a plurality of third basic mesh cells C3 that have the same shape as the first basic mesh cell C1 and the second basic mesh cell C2 and 1 / 4 the size (area).
[0035] The multiple second wirings 22 arranged in the first dummy electrode 14 constitute a part of the third mesh pattern P3 in a plan view, so that the presence of the second wirings 22 is not noticeable when a user views the touch panel. In addition, the first ground wiring G1 arranged in the first dummy electrode 14 also constitutes a part of the third mesh pattern P3, so that the presence of the first ground wiring G1 is not noticeable when a user views the touch panel.
[0036] 7, the connection portion 31 in the opening portion H is disposed at the intersection of the first mesh pattern P1 and the second mesh pattern P2 in a plan view. This improves the electrical continuity between the second wiring 22 and the second detection electrode 21, making the presence of the opening portion H and the connection portion 31 less noticeable.
[0037] From the above, according to the touch panel of the first embodiment of the present invention, the insulating layer 1 has a plurality of connection parts 31 penetrating the insulating layer 1 and connecting the plurality of second detection electrodes 21 and the plurality of second wirings 22 to each other, and both the plurality of first wirings 12 and the plurality of second wirings 22 are drawn in the same direction, so that the peripheral region R2 in which the plurality of first wirings 12 and the plurality of second wirings 22 are arranged can be narrowed, thereby making it possible to narrow the frame of the touch panel. In addition, since the corresponding second wirings 22 and the second detection electrodes 21 are connected to each other by two or more connection parts 31, even if a crack or break occurs in any of the two or more connection parts 31 connecting the corresponding second wirings 22 and the second detection electrodes 21, for example, the electrical connection between the second wirings 22 and the second detection electrodes 21 can be maintained.
[0038] Embodiment 2 Although it is shown that the opening H and connection portion 31 of the insulating layer 1 are positioned at the intersection of the first mesh pattern P1 and the second mesh pattern P2 in a planar view and at the intersection of the side of the first basic mesh cell C1 and the side of the second basic mesh cell C2, the opening H and connection portion 31 can also be positioned, for example, at the intersection of the first mesh pattern P1 and the second mesh pattern P2 in a planar view and at the intersection of the second mesh pattern P2.
[0039] FIG. 8 shows a plan view of an enlarged portion of the first conductive layer 2A in the second embodiment. The second wiring pattern M3 formed by the second wiring 22 is formed by a plurality of first basic mesh cells C1 and a plurality of third basic mesh cells C3 having the same shape as the first basic mesh cell C1 and 1 / 4 the size of the first basic mesh cell C1. Therefore, the second wiring pattern M3 has a fourth mesh pattern P4 different from the first mesh pattern P1 and the second mesh pattern P2. As will be described later, the fourth mesh pattern P4 is a pattern included in the third mesh pattern P3. By using the fourth mesh pattern P4 including the third basic mesh cell C3 smaller than the first basic mesh cell C1, it is possible to reduce the resistance of the second wiring 22, and the sensitivity of the touch panel can be improved.
[0040] In addition, the ground wiring pattern M4 formed by the first ground wiring G1 is formed by a plurality of first basic mesh cells C1 and a plurality of third basic mesh cells C3, and has a fifth mesh pattern P5 different from the first mesh pattern P1, the second mesh pattern P2, and the fourth mesh pattern P4. As will be described later, the fifth mesh pattern P5 is also a pattern included in the third mesh pattern P3, similar to the fourth mesh pattern P4. By using the fifth mesh pattern P5 including the third basic mesh cell C3 smaller than the first basic mesh cell C1, it is possible to reduce the resistance of the first ground wiring G1, improve the electromagnetic wave shielding effect described above, and improve the sensitivity of the touch panel.
[0041] Here, since the second wiring pattern M3 is formed by a plurality of first basic mesh cells C1 and a plurality of third basic mesh cells C3, the wiring density of the second wiring 22 in the second wiring pattern M3 is greater than the wiring density of the first detection electrode 11. As a result, even if a break occurs in the second wiring 22, the electrical connection between the second detection electrode 21 and the second electrode pad 23 can be maintained, and the electrical resistance of the second wiring pattern M3 is low, improving the detection sensitivity for touch operations. In addition, the wiring density of the first ground wiring G1 in the ground wiring pattern M4 is also greater than the wiring density of the first detection electrode 11, similar to the second wiring pattern M3. As a result, it is possible to reduce the resistance of the first ground wiring G1. Here, the wiring density refers to the ratio of the area occupied by the thin metal wires to the area of a certain region. For example, the wiring density of the second wiring 22 indicates the ratio of the area occupied by the first metal thin wire A1 to the area of the area occupied by the second wiring 22 when viewed in a planar view, and the wiring density of the first detection electrode 11 indicates the ratio of the area occupied by the first metal thin wire A1 to the area of the area occupied by the first detection electrode 11 when viewed in a planar view.
[0042] 8, three openings H are arranged at the vertices of the third basic mesh cell C3, which is located at the center of each of the three first basic mesh cells C1 arranged adjacent to each other in the second wiring pattern M3. Therefore, the corresponding second wirings 22 and second detection electrodes 21 are electrically connected to each other by the three connection parts 31 formed in the three openings H.
[0043] 9 shows an enlarged plan view of a part of a touch area R1 of a touch panel in which the first conductive layer 2A and the second conductive layer 2B are combined in a plan view in accordance with the second embodiment. In the touch area R1, the first thin metal wires A1 of the first conductive layer 2A and the second thin metal wires A2 of the second conductive layer 2B are combined with each other in a plan view to configure a third mesh pattern P3 formed by a plurality of third basic mesh cells C3.
[0044] The fourth mesh pattern P4 formed by the second wiring 22 and the fifth mesh pattern P5 formed by the first ground wiring G1 each constitute a part of the third mesh pattern P3. Therefore, when a user visually checks the touch panel, the presence of the second wiring 22 and the first ground wiring G1 is not noticeable.
[0045] In addition, the three openings H and the three connection parts 31 formed therein are intersections of the fourth mesh pattern P4 and the second mesh pattern P2 in a plan view, and are arranged at the intersections of the second mesh pattern P2. Therefore, the presence of the openings H and the connection parts 31 is not noticeable. In addition, generally, the intersections of a mesh pattern formed of fine metal wires tend to have a wider line width than other parts of the mesh pattern. Therefore, by arranging the connection parts 31 at the intersections of the second mesh pattern P2, the openings H can be made larger, thereby improving the reliability of the electrical connection between the second fine metal wires A2 of the second detection electrode 21 and the connection parts 31.
[0046] From the above, according to the touch panel of embodiment 2, the second wiring pattern M3 having the fourth mesh pattern P4 is formed by the second wiring 22, and two or more openings H and connection portions 31 are arranged at the intersections of the fourth mesh pattern P4 and the second mesh pattern P2 in a planar view and at the intersections of the second mesh pattern P2, thereby improving the reliability of the electrical connection between the second detection electrode 21 and the connection portions 31 while narrowing the frame of the touch panel. In addition, in the second wiring 22 and the first ground wiring G1 of the touch panel of embodiment 2 shown in Figures 8 and 9, a third basic mesh cell C3 smaller than the first basic mesh cell C1 is arranged between the second detection electrodes 21 of the second conductive layer 2B, i.e., at the position of the second dummy electrode 24, in a planar view. Therefore, the second wiring 22 and the first ground wiring G1 do not increase the parasitic capacitance of the touch panel, and the resistance of the second wiring 22 and the first ground wiring G1 can be reduced, thereby further improving the sensitivity of the touch panel.
[0047] Each component constituting the touch panel will be described below. <Insulating layer> The insulating layer 1 is not particularly limited as long as it is transparent, electrically insulating, and can support the first conductive layer 2A and the second conductive layer 2B, but examples of the material that can be used to form the insulating layer 1 include glass, reinforced glass, non-alkali glass, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), cyclo-olefin polymer (COP), cyclic olefin copolymer (COC), polycarbonate (PC), acrylic resin, polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), and cellulose triacetate (TAC). The total light transmittance of the insulating layer 1 is preferably 40% to 100%. The total light transmittance is measured, for example, using "Plastics--Determination of total light transmittance and total light reflectance" as specified in JIS K 7375:2008.
[0048] <Thin metal wire> The first thin metal wires A1 in the first conductive layer 2A and the second thin metal wires A2 in the second conductive layer 2B are thin metal wires with a line width of 0.5 μm to 10 μm. More preferably, the first thin metal wires A1 and the second thin metal wires A2 have a line width of 1.0 μm to 5.0 μm. Preferred materials for the first thin metal wires A1 and the second thin metal wires A2 include silver, copper, aluminum, gold, molybdenum, chromium, etc., and alloys, oxides, or laminates thereof can be used. In particular, silver or copper is preferred from the viewpoint of resistance value, and thin metal wires with laminated structures such as molybdenum / aluminum / molybdenum, molybdenum / copper / molybdenum, copper oxide / copper oxide, etc. can be used.
[0049] The film thickness of the first thin metal wires A1 and the second thin metal wires A2 is 0.05 μm to 10 μm, and preferably 0.1 μm to 1 μm. In order to improve the visibility of the first thin metal wires A1 and the second thin metal wires A2, a blackened layer may be provided on the first thin metal wires A1 and the second thin metal wires A2, or between the first thin metal wires A1 and the insulating layer 1, and between the second thin metal wires A2 and the insulating layer 1. Copper oxide, molybdenum oxide, etc. can be used as the blackened layer.
[0050] In addition, the touch panel may be provided with the following additional layers as required: <Protective layer> A protective layer can be provided to cover the first fine metal wire A1 and the second fine metal wire A2 in order to protect them. As the protective layer, an organic film such as gelatin, acrylic resin, or urethane resin, or an inorganic film such as silicon dioxide can be used, and the film thickness is preferably 0.01 μm or more and 10 μm or less. In addition, a transparent coating layer can be formed on the protective layer. As the transparent coating layer, an organic film such as acrylic resin or urethane resin is used, and the film thickness is preferably 1 μm or more and 100 μm or less.
[0051] <Undercoat layer> An undercoat layer can be provided between the insulating layer 1 and the first conductive layer 2A, or between the insulating layer 1 and the second conductive layer 2B, in order to strengthen adhesion. As the undercoat layer, an organic film such as gelatin, acrylic resin, urethane resin, or polyester resin, or an inorganic film such as silicon dioxide can be used, and the thickness of the layer is preferably 0.01 μm or more and 10 μm or less.
[0052] <Planarization layer> A planarizing layer can be provided between the insulating layer 1 and the first conductive layer 2A, or between the insulating layer 1 and the second conductive layer 2B, in order to planarize the surface of the insulating layer 1. As the planarizing layer, an organic film such as an acrylic resin, a urethane resin, or a polyester resin can be used, and the film thickness is preferably 0.01 μm or more and 10 μm or less. In particular, when a decorative layer is provided on the insulating layer 1, it is preferable to provide a planarizing layer.
[0053] <Cover material> The cover member is transparent and electrically insulating. Examples of the material that can be used for the cover member include glass, reinforced glass, alkali-free glass, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), cyclo-olefin polymer (COP), cyclic olefin copolymer (COC), polycarbonate (PC), acrylic resin, polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), and cellulose triacetate (TAC). The cover member can be used as a substrate supporting the first conductive layer 2A and the second conductive layer 2B, and the touch panel can be configured by sequentially stacking the cover member / first conductive layer 2A / insulating layer 1 / second conductive layer 2B, or by sequentially stacking the cover member / second conductive layer 2B / insulating layer 1 / first conductive layer 2A.
[0054] Next, a method for forming the first conductive layer 2A and the second conductive layer 2B will be described. As a method for forming these layers, for example, a sputtering method, a plating method, a silver halide method, etc. can be appropriately used. A method for forming the first conductive layer 2A and the second conductive layer 2B by a sputtering method will be described. First, a copper foil layer is formed by sputtering, and then copper wiring is formed from the copper foil layer by a photolithography method, thereby forming the first conductive layer 2A and the second conductive layer 2B. Note that instead of sputtering, the copper foil layer can also be formed by so-called vapor deposition. As the copper foil layer, in addition to sputtered copper foil or vapor-deposited copper foil, electrolytic copper foil can also be used. More specifically, the process for forming copper wiring described in JP 2014-29614 A can be used.
[0055] A method for forming the first conductive layer 2A and the second conductive layer 2B by a plating method will be described. For example, the first conductive layer 2A and the second conductive layer 2B can be formed using a metal plating film formed on an electroless plating base layer by applying electroless plating to the base layer. In this case, the first conductive layer 2A and the second conductive layer 2B are formed by forming a pattern of a catalyst ink containing at least metal fine particles on a substrate, and then immersing the substrate in an electroless plating bath to form a metal plating film. More specifically, a method for manufacturing a metal-coated substrate described in JP 2014-159620 A can be used.
[0056] The first conductive layer 2A and the second conductive layer 2B are formed by forming a pattern of a resin composition having at least a functional group capable of interacting with a metal catalyst precursor on a substrate, applying a catalyst or a catalyst precursor, and immersing the substrate in an electroless plating bath to form a metal plating film. More specifically, the method for producing a metal-coated substrate described in JP 2012-144761 A can be applied.
[0057] A method for forming the first conductive layer 2A and the second conductive layer 2B by the silver salt method will be described. First, an exposure process is performed on a silver salt emulsion layer containing silver halide in a state where an exposure pattern that becomes the first conductive layer 2A and the second conductive layer 2B is formed and a glass mask with a locally different exposure amount is arranged, and then a development process is performed, thereby forming the first conductive layer 2A and the second conductive layer 2B. More specifically, the manufacturing methods of metal thin wires described in JP2012-6377A, JP2014-112512A, JP2014-209332A, JP2015-22397A, JP2016-192200A, and WO2016 / 157585A can be used.
[0058] The present invention is basically configured as described above. Although the touch panel of the present invention has been described in detail above, the present invention is not limited to the above-mentioned embodiment, and various improvements or modifications may be made without departing from the spirit and scope of the present invention. [Explanation of symbols]
[0059] 1 insulating layer, 1A first surface, 1B second surface, 2A first conductive layer, 2B second conductive layer, 11 first detection electrode, 12 first wiring, 13 first electrode pad, 14 first dummy electrode, 21 second detection electrode, 22 second wiring, 23 second electrode pad, 24 second dummy electrode, 31 connection portion, A1 first metal thin wire, A2 second metal thin wire, B disconnection portion, C1 first basic mesh cell, C2 second basic mesh cell, C3 third basic mesh cell, D1 first extension direction, D2 second extension direction, G1 first ground wiring, H opening, M1, M3 second wiring pattern, M2, M4 ground wiring pattern, P1 first mesh pattern, P2 second mesh pattern, P3 third mesh pattern, P4 fourth mesh pattern, P5 fifth mesh pattern, R1 touch area, R2 peripheral area.
Claims
1. A touch panel having a touch area and a peripheral area outside the touch area, a first conductive layer made of a first thin metal wire, an insulating layer, and a second conductive layer made of a second thin metal wire are laminated in this order; the first conductive layer is formed in the touch area, and includes a plurality of first detection electrodes extending along a first direction and arranged in a second direction perpendicular to the first direction, a plurality of first dummy electrodes arranged between the plurality of first detection electrodes and insulated from the plurality of first detection electrodes, a plurality of first wirings formed in the peripheral area and connected to the plurality of first detection electrodes, and a plurality of second wirings arranged on the plurality of first dummy electrodes; the second conductive layer is formed in the touch area and has a plurality of second detection electrodes extending along the second direction and arranged in the first direction; a plurality of connection portions that penetrate the insulating layer and connect the plurality of second detection electrodes and the plurality of second wirings to each other; In plan view, the first detection electrodes have a first mesh pattern formed by the first thin metal wires, the second detection electrodes have a second mesh pattern formed by the second thin metal wires, In the touch area, the first mesh pattern and the second mesh pattern are combined with each other in a plan view to form a third mesh pattern; the second wirings correspond to the second detection electrodes, The second wiring and the second detection electrode corresponding to each other are connected to each other by two or more of the connection parts. Touch panel.
2. The second wiring and the second detection electrode corresponding to each other are connected to each other by three or more of the connection parts. The touch panel according to claim 1 .
3. The connection portions are disposed at the intersections of the second mesh pattern. The touch panel according to claim 1 or 2.
4. the first dummy electrode has the first mesh pattern in a plan view, The connection portion is disposed at an intersection portion between the first mesh pattern and the second mesh pattern in a plan view. The touch panel according to claim 1 or 2.
5. The connection portion is made of a conductive material different from the conductive material that constitutes the second detection electrode and the second wiring. The touch panel according to claim 1 or 2.
6. The conductive material of the connection portion is a transparent conductive material. The touch panel according to claim 5 .
7. the first dummy electrode has the first mesh pattern in a plan view, The second wiring constitutes a part of the first mesh pattern in a plan view. The touch panel according to claim 1 or 2.
8. the first dummy electrode has a first ground wiring that is disposed between the first detection electrode and the second wiring and is insulated from the first detection electrode and the second wiring; The first ground wiring constitutes a part of the first mesh pattern. The touch panel according to claim 1 or 2.
9. The first thin metal wire has at least two or more breaks adjacent to each other in an extending direction of the first thin metal wire between the second wiring and the first detection electrode adjacent to the second wiring. The touch panel according to claim 1 or 2.
10. The first thin metal wire has at least two or more breaks adjacent to each other in an extending direction of the first thin metal wire between the first ground wiring and the first detection electrode adjacent to the first ground wiring, and between the first ground wiring and the second wiring adjacent to the first ground wiring. The touch panel according to claim 8.
11. The thickness of the insulating layer is 0.5 μm or more and 5.0 μm or less. The touch panel according to claim 1 or 2.
Citation Information
Patent Citations
Touch screen and display device including the touch screen
JP2021157421A
