WIRING BODY AND WIRING BODY ASSEMBLY

A wiring body includes: a first insulator; a conductor disposed on a first surface of the first insulator and that includes a terminal; and a second insulator disposed on the first surface to cover the conductor. The second insulator includes: an opening from which the terminal is exposed; and an end face that delimits the opening and that includes a first face, a second face that is farther away from the first insulator than the first face, and an edge that connects the first face and the second face.

TECHNICAL FIELD

The present invention relates to a wiring body and a wiring body assembly in which two wiring bodies are connected by a conductive bonding portion.

For designated countries that are permitted to be incorporated by reference in the literature, the contents described in Japanese Patent Application No. 2017-005654 filed in Japan on Jan. 17, 2017 is incorporated herein by reference and made a part of the description of this specification.

BACKGROUND

As a connection structure of a silver electrode terminal of a color plasma display panel and a flexible printed circuit (hereinafter, referred to as FPC), a structure in which an exposed part of the silver electrode terminal is sealed with a resin is known (for example, see Patent Document 1).

PATENT DOCUMENT

Patent Document 1: JP 2001-015042 A

In a connection structure of an FPC and a wiring body that includes a first resin portion, a conductive portion including a terminal portion formed on a surface of the first resin, and a second resin portion covering the conductive portion excluding the terminal portion, in a case where an exposed part of the terminal portion of the wiring body is sealed with a sealing resin, the sealing resin is wetted and spreads on an upper face of the second resin portion to impair flatness of the entire wiring body.

SUMMARY

One or more embodiments of the invention provide a wiring body and a wiring body assembly that are excellent in flatness.

[1] A wiring body according to one or more embodiments the invention is a wiring body including: a first insulating portion; a conductive portion that is formed on one surface of the first insulating portion and includes at least a terminal portion; and a second insulating portion that is formed on the one surface to cover the conductive portion, in which the second insulating portion includes an opening portion from which the terminal portion is exposed, and an end face of the second insulating portion that defines the opening portion includes: a first face; a second face that is farther from the first insulating portion than the first face; and an edge portion that connects the first face and the second face.

[2] In one or more embodiments of the invention, the edge portion may be continuously formed along a horizontal direction over the entire region of the end face.

[3] In one or more embodiments of the invention, a convex portion may be formed in the end face by the edge portion protruding toward the inside of the opening portion, the first face may include a curved portion that approaches the edge portion as being separated from the first insulating portion and is curved toward the inner side of the convex portion, the curved portion may include: a first part; and a second part that is farther from the edge portion than the first part, and a curvature radius of the first part may be smaller than a curvature radius of the second part.

[4] In one or more embodiments of the invention, a protrusion portion that protrudes toward the inside of the opening portion may be formed at a lower end of the second face.

[5] A wiring body assembly according to one or more embodiments of the invention is a wiring body assembly including: the above-described first wiring body; a second wiring body that includes a substrate and a connection terminal portion formed on the other surface of the substrate, the connection terminal portion being overlapped with the first wiring body in the opening portion to face the terminal portion; and a conductive bonding portion that is formed between the terminal portion and the connection terminal portion and connects the terminal portion and the connection terminal portion, in which a gap is formed between the second wiring body and the end face by the second wiring body and the end face being separated from each other, and the wiring body assembly includes a sealing resin filled in at least the gap.

[6] In one or more embodiments of the invention, the sealing resin is not in contact with the second face.

[7] In one or more embodiments of the invention, the sealing resin may be in contact with one surface of the second wiring body.

[8] In one or more embodiments of the invention, the following Expression (1) may be satisfied:

in the above Expression (1), H2is a height from the one surface of the first insulating portion to one surface of the second insulating portion, and H3is a height from one surface of the first insulating portion to the edge portion.

[9] In one or more embodiments of the invention, the following Expression (2) is satisfied:

in the above Expression (2), H3is a height from the one surface of the first insulating portion to the edge portion, and H4is a height from the one surface of the first insulating portion to one surface of the second wiring body.

[10] In one or more embodiments of the invention, the following Expression (3) is satisfied:

H2is a height from the one surface of the first insulating portion to one surface of the second insulating portion, and ti is a maximum thickness of the sealing resin.

According to one or more embodiments of the invention, since wetting and spreading of the sealing resin on an upper face of the second resin portion can be suppressed, a wiring body excellent in flatness can be obtained.

DETAILED DESCRIPTION

Hereinafter, embodiments of the invention will be described on the basis of drawings.

FIG. 1is a plan view illustrating a touch sensor according to one or more embodiments of the invention,FIG. 2is an exploded perspective view of the touch sensor according to one or more embodiments, andFIG. 3is a plan view illustrating a connection part of a first wiring body and a second wiring body in an enlarged manner according to one or more embodiments.

A touch sensor1illustrated inFIG. 1is a touch panel sensor corresponding to a projection-type capacitive sensing method, and for example, is used as an input device having a function of detecting a touch position in combination with a display device (not illustrated) or the like. The display device is not particularly limited, and a liquid crystal display, an organic EL display, an electronic paper, or the like can be used as the display device. This touch sensor1has a detection electrode and a driving electrode (first and second electrode portions521and541which will be described later) that are disposed to face each other, and a predetermined voltage is periodically applied to between the two electrodes from an external circuit (not illustrated) via a second wiring body60.

In such a touch sensor1, for example, as an operator's finger (external conductor) approaches the touch sensor1, a capacitance (electrostatic capacitance) is formed between the external conductor and the touch sensor1, so that an electric state between the two electrodes changes. The touch sensor1can detect an operation position of the operator on the basis of an electric change between the two electrodes.

As illustrated inFIG. 1andFIG. 2, the touch sensor1includes a cover panel20, a transparent adhesive layer30, and a wiring body assembly40that is provided on one surface of the cover panel20via the transparent adhesive layer30.

The cover panel20has a rectangular outer shape and includes: a transparent portion21that allows transmission of visible light rays; and a shielding portion22that shields visible light rays. The transparent portion21is formed in a rectangular shape, and the shielding portion22is formed in a rectangular frame shape around the transparent portion21. Examples of a transparent material forming the cover panel20may include glass materials such as soda-lime glass and borosilicate glass and resin materials such as polymethylmethacrylate (PMMA) and polycarbonate (PC). Further, the shielding portion22is formed at an outer circumference portion of a rear surface of the cover panel20, for example, by applying black ink. A first wiring body50(described later) of the wiring body assembly40is pasted on the cover panel20, and this first wiring body50is supported by the cover panel20. In this case, the cover panel20has a stiffness enough to support the first wiring body50.

The transparent adhesive layer30is interposed between the cover panel20and the wiring body assembly40. This transparent adhesive layer30is an optical transparent adhesive film and can be formed using a known adhesive such as a silicone resin-based adhesive, an acrylic resin-based adhesive, a urethane resin-based adhesive, or a polyester resin-based adhesive. In one or more embodiments, although the transparent adhesive layer30is formed on the lower surface of the cover panel20in advance, in a case where a layer of the wiring body assembly40at the cover panel20side is an adhesive layer, formation of the transparent adhesive layer30is not necessary, so that the transparent adhesive layer30may be omitted.

As illustrated inFIG. 1toFIG. 3, the wiring body assembly40includes the first wiring body50, the second wiring body60, a conductive bonding portion70, and a sealing resin80.

As illustrated inFIG. 2, the first wiring body50includes a first resin portion51, a first conductive portion52, a second resin portion53, a second conductive portion54, and a third resin portion55. This first wiring body50is configured to have transparency (translucency) as a whole in order to secure visibility of the display device.

The first resin portion51has a rectangular outer shape and is made of a resin material having transparency. Examples of this resin material having transparency may include UV curable resins, thermosetting resins, or thermoplastic resins such as an epoxy resin, an acrylic resin, a polyester resin, a urethane resin, a vinyl resin, a silicone resin, a phenol resin, and a polyimide resin.

The first conductive portion52is provided on the upper surface of the first resin portion51(a surface, which is positioned at a side facing the second wiring body60(specifically, a first branch portion601(described later)), of main surfaces of the first resin portion51), and is held by the first resin portion51. This first conductive portion52includes a plurality of first electrode portions521, a plurality of first lead wirings522, and a plurality of first terminal portion523. The first electrode portion521has a mesh shape. Each first electrode portions521extends in a Y direction in the drawing, and the plurality of first electrode portions521are juxtaposed in an X direction in the drawing. One end of the first lead wiring522is connected to one longitudinal direction end of each first electrode portion521. The first terminal portion523is connected to other end of each first lead wiring522.

The number of the first electrode portions521is not particularly limited, but can be arbitrarily set. Further, the number of the first lead wiring522and the number of the first terminal portions523are set depending on the number of the first electrode portions521.

The first conductive portion52is made of a conductive material (conductive particles) and a binder resin. Examples of the conductive material may include metal materials such as silver, copper, nickel, tin, bismuth, zinc, indium, and palladium, and carbon-based materials such as graphite, carbon black (furnace black, acetylene black, Ketjen black), carbon nanotube, and carbon nanofiber. A metal salt may be used as the conductive material. As the metal salt, salts of the aforementioned metals can be exemplified. Examples of the binder resin may include an acrylic resin, a polyester resin, an epoxy resin, a vinyl resin, a urethane resin, a phenol resin, a polyimide resin, a silicone resin, and a fluoride resin. Such a first conductive portion52is formed by applying and curing a conductive paste. Specific examples of such a conductive paste may include a conductive paste formed by mixing the aforementioned conductive material and binder resin with water or a solvent and various additives. Examples of a solvent contained in the conductive paste may include a-terpineol, butyl carbitol acetate, butyl carbitol, 1-decanol, butyl cellosolve, diethylene glycol monoethyl ether acetate, and tetradecane. The binder resin may be omitted from materials forming the first conductive portion52.

The second resin portion53has a rectangular outer shape and is formed by a resin material having transparency. As the resin material having transparency, for example, the same materials as the resin materials forming the first resin portion51described above can be used.

The second resin portion53is formed to cover the upper surface of the first resin portion51, the first electrode portion521, and the first lead wiring522. The second resin portion53is formed with a first opening portion531, and the first terminal portion523is exposed from this first opening portion531.

The second conductive portion54is provided on the upper surface of the second resin portion53(a surface, which is positioned at a side facing the second wiring body60(specifically, a second branch portion602(described later)), of main surfaces of the second resin portion53). This second conductive portion54includes a plurality of second electrode portions541, a plurality of second lead wirings542, and a plurality of second terminal portions543. The second electrode portion541has a mesh shape. Each second electrode portion541extends in the X direction in the drawing, and the plurality of second electrode portions541are juxtaposed in the Y direction in the drawing. One end of the second lead wiring542is connected to one longitudinal direction end of each second electrode portion541. Each second lead wiring542extends from one longitudinal direction end of each second electrode portion541to a connection part with the second wiring body60. The second terminal portion543is connected to other end of each second lead wiring542.

The number of the second electrode portions541is not particularly limited, but can be arbitrarily set. Further, the number of the second lead wirings542and the number of the second terminal portions543are set depending on the number of the second electrode portions541.

The second conductive portion54is made of a conductive material (conductive particles) and a binder resin similarly to the first conductive portion52. Such a second conductive portion54is also formed by applying and curing a conductive paste similarly to the first conductive portion52.

The third resin portion55has a rectangular outer shape and is made of a resin material having transparency. As the resin material having transparency, for example, the same materials as the resin materials forming the first resin portion51described above can be used.

The third resin portion55is formed to cover the upper surface of the second resin portion53, the second electrode portion541, and the second lead wiring542. The third resin portion55is formed with a second opening portion551, and the second terminal portion543is exposed from this second opening portion551.

Further, the upper surface of the third resin portion55is formed to be substantially flat. This upper surface of the third resin portion55is pasted to the cover panel20via the transparent adhesive layer30.

The second wiring body60is a flexible printed circuit (FPC). In one or more embodiments, as illustrated inFIG. 3, a slit603is formed at the width direction center of the one longitudinal direction end of the second wiring body60, and the one longitudinal direction end of the second wiring body60is bisected by the slit603. One side (the first branch portion601) of one longitudinal direction end of the second wiring body60corresponds to the first terminal portion523. Meanwhile, the other side (the second branch portion602) of one longitudinal direction end of the second wiring body60corresponds to the second terminal portion543.

This second wiring body60includes: a strip-like substrate61; and third and fourth conductive portions62and63that are formed on a lower surface of the substrate61(a surface, which is positioned at a side facing the first wiring body50, of main surfaces of the substrate61).

The substrate61can be formed, for example, from a film material such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide resin (PI), or polyetherimide resin (PEI).

The third conductive portion62is formed on a lower surface of the first branch portion601and includes a plurality of third lead wirings621and a plurality of third terminal portions622. The third lead wiring621extends along the first branch portion601. One longitudinal direction end of the third lead wiring621is connected to the third terminal portion622. The third terminal portion622is disposed in the vicinity of the tip end of the first branch portion601. Each of the plurality of third terminal portions622faces each of the plurality of first terminal portions523.

The fourth conductive portion63is formed on a lower surface of the second branch portion602and includes a plurality of fourth lead wirings631and a plurality of fourth terminal portions632. The fourth lead wiring631extends along the second branch portion602. One longitudinal direction end of the fourth lead wiring631is connected to the fourth terminal portion632. The fourth terminal portion632is disposed in the vicinity of the tip end of the second branch portion602. Each of the plurality of fourth terminal portions632faces each of the plurality of second terminal portions543.

The second wiring body60is not limited to the FPC, and for example, other wiring boards such as a rigid board and a rigid flexible board may be employed.

Next, the connection part of the first wiring body50and the second wiring body60will be described in more detail with reference toFIG. 4toFIG. 7.FIG. 4is a cross-sectional view taken along the line IV-IV ofFIG. 3,FIG. 5is a cross-sectional view taken along the line V-V ofFIG. 3,FIG. 6is a perspective view of a first opening portion and a second opening portion when viewed from the upper side, andFIG. 7is a partially enlarged view of a part VII ofFIG. 4.

In one or more embodiments, as illustrated inFIG. 4, the first wiring body50and the tip end of the first branch portion601are overlapped in a region of the first opening portion531. The conductive bonding portion70is interposed between the first wiring body50and the first branch portion601, and this conductive bonding portion70electrically and mechanically connects the first wiring body50(particularly, the first terminal portion523) and the first branch portion601(particularly, the third terminal portion622).

In a state in which the first wiring body50and the tip end of the first branch portion601are overlapped, a height H2from the upper surface of the first resin portion51to the upper surface of the second resin portion53is larger than a height H4from the upper surface of the first resin portion51to the upper surface of the first branch portion601(the upper surface of the second wiring body60) (H2>H4). The height H4is not particularly limited to the above as long as the height H4is smaller than a height Hi from the upper surface of the first resin portion51to the upper surface of the third resin portion55(H1>H4).

Furthermore, in one or more embodiments, a height H3from the upper surface of the first resin portion51to an edge portion (a corner portion, a ridge portion)535is smaller than the height H4from the upper surface of the first resin portion51to the upper surface of the first branch portion601(the upper surface of the second wiring body60) (H3<H4). According to this, since it is difficult for the sealing resin80to spread on the upper surface of the second resin portion53, it is possible to obtain a wiring body that is excellent in flatness.

Similarly, as illustrated inFIG. 5, the first wiring body50and the tip end of the second branch portion602are overlapped in a region of the second opening portion551. The conductive bonding portion70is interposed between the first wiring body50and the second branch portion602, and this conductive bonding portion70electrically and mechanically connects the first wiring body50(particularly, the second terminal portion543) and the second branch portion602(particularly, the fourth terminal portion632).

In a state in which the first wiring body50and the tip end of the second branch portion602are overlapped, a height Hs from the upper surface of the second resin portion53to the upper surface of the third resin portion55is larger than a height H7from the upper surface of the second resin portion53to the upper surface of the second branch portion602(H5>H7).

Examples of such a conductive bonding portion70may include an anisotropic conductive film (ACF) and an anisotropic conductive paste (ACP). The first terminal portion523and the third terminal portion622, and the second terminal portion543and the fourth terminal portion632may electrically and mechanically connected using a metal paste such as a silver paste and a solder paste without using an anisotropic conductive material. In this case, it is necessary to form a plurality of bonding portions at intervals in order to insulate the neighboring terminals.

As illustrated inFIG. 3, the first opening portion531is formed in a rectangular shape in plan view and is disposed at one side of the second resin portion53(one side positioned at an edge portion of the first wiring body50intersecting the first branch portion601).

As illustrated inFIG. 4, an end face532of the second resin portion53which defines this first opening portion531includes: a lower side face533; an upper side face534; and an edge portion535that connects the lower side face533and the upper side face534in cross-sectional view (in cross-sectional view in the case of being cut in a height direction along an extending direction of the first terminal portion523).

The edge portion535protrudes toward the region of the first opening portion531. According to this, the end face532is formed with a convex portion536protruding toward the region of the first opening portion531. In one or more embodiments, a curvature radius of this edge portion535is 5 μm or less. The height H3from the upper surface of the first resin portion51to the edge portion535is smaller than the height H2from the upper surface of the first resin portion51to the upper surface of the second resin portion53(H2>H3).

As illustrated inFIG. 6, the edge portion535is continuously formed along a horizontal direction over the entire region of three end faces532defining the first opening portion531. Further, also in a part at which two end faces532and532are connected to each other, the edge portion535is continuously formed.

As illustrated inFIG. 4, the lower side face533is positioned at the lower side (a side close to the first resin portion51) with respect to the edge portion535. The lower side face533includes a curved portion5331that approaches the edge portion535as being separated from the first resin portion51and is curved toward the inner side of the convex portion536. As illustrated inFIG. 7, the curved portion5331includes: a first part (first curve)5331aclose to the edge portion535; and a second part (second curve)5331bthat is farther from the edge portion than the first part5331a,and a curvature radius of the curved portion5331varies in these first part5331aand second part5331b.Specifically, a curvature radius of the first part5331ais smaller than a curvature radius of the second part5331b.

As illustrated inFIG. 4, the upper side face534is positioned at the upper side with respect to the lower side face533and the edge portion535(a side far away from the first resin portion51). The upper side face534extends in a direction different form that of the lower side face533, and in one or more embodiments, the upper side face534is an inclined face that is inclined to be separated from the edge portion535as being separated from the first resin portion51. In this case, as illustrated inFIG. 7, an angle a formed between a virtual straight line L along the lower side face533in the vicinity of the edge portion535and the upper side face534in the vicinity of the edge portion535is a positive value in a case where the clockwise rotation direction about the edge portion535is regarded to be positive.

As illustrated inFIG. 4, in the region of the first opening portion531, the tip end of the first branch portion601and the end face532of the first opening portion531are separated from each other, and according to this, a gap91is formed between the first branch portion601and the end face532. In the gap91, a part of the first terminal portion523is exposed from the first branch portion601, the conductive bonding portion70and the second resin portion53.

In the region of the first opening portion531including at least the gap91, the sealing resin80is filled. The first terminal portion523exposed from the first branch portion601, the conductive bonding portion70and the second resin portion53is covered with the sealing resin80.

This sealing resin80is in contact with the lower side face533and the edge portion535in an interface with the end face532and the first opening portion531, but the sealing resin80is not in contact with the upper side face534. That is, spreading to a height direction of the sealing resin80in the interface with the end face532extends to the position of the edge portion535. In this way, since spreading to the height direction of the sealing resin80in the interface with the end face532can be set to extend to the position of the edge portion535by allowing the upper side face534not to be in contact with the sealing resin80, it is possible to obtain a wiring body that is excellent in flatness.

Meanwhile, the sealing resin80spreads on and is in contact with the upper surface of the first branch portion601(the upper surface of the second wiring body60) along the extending direction of the first branch portion601. In this way, by the sealing resin80covering the vicinity of the tip end of the first branch portion601, reliability of connection strength between the first wiring body50and the second wiring body60is improved.

In one or more embodiments, a maximum thickness ti of the sealing resin80(a height from the upper surface of the first resin portion51to a part of the sealing resin80which most protrudes) is equal to or lower than the height Hi from the upper surface of the first resin portion51to the upper surface of the third resin portion55(H1≥t1). Further, in one or more embodiments, the maximum thickness ti of the sealing resin80is equal to or lower than the height H2from the upper surface of the first resin portion51to the upper surface of the second resin portion53(H2≥t1). Therefore, since the sealing resin80does not protrude to the upper side in relation to the upper surface of the third resin portion55, it is difficult for the sealing resin80to spread on the upper surface of the second resin portion53. Thus, it is possible to obtain a wiring body that is excellent in flatness.

Further, in one or more embodiments, the maximum thickness t1of the sealing resin80is larger than the height H3from the upper surface of the first resin portion51to the edge portion535(t1>H3). Therefore, the sealing resin80is in contact with the upper surface of the first branch portion601, and reliability of connection strength between the first wiring body50and the second wiring body60is improved.

Examples of the resin material forming such a sealing resin80may include UV curable resins, thermosetting resins, or thermoplastic resins such as an epoxy resin, an acrylic resin, a polyester resin, a urethane resin, a vinyl resin, a silicone resin, a phenol resin, and a polyimide resin.

As illustrated inFIG. 3, the second opening portion551is formed in a rectangular shape in plan view and is disposed at one side of the third resin portion55(one side positioned at an edge portion of the first wiring body50intersecting the second branch portion602). This second opening portion551is larger than the first opening portion531in plan view. Further, in plan view, the first opening portion531and the second opening portion551are overlapped. Therefore, the second terminal portion543is exposed from the second opening portion551and the first terminal portion523exposed from the first opening portion531is also exposed from the second opening portion551.

As illustrated inFIG. 5, an end face552of the third resin portion55which defines this second opening portion551includes: a lower side face553; an upper side face554; and a edge portion555that connects the lower side face553and upper side face554in cross-sectional view (in cross-sectional view in the case of being cut along the extending direction of the second terminal portion543).

The edge portion555protrudes toward the region of the second opening portion551. According to this, the end face552is formed with a convex portion556protruding toward the region of the second opening portion551. In one or more embodiments, a curvature radius of this edge portion555is 5 μm or less. A height H6from the upper surface of the second resin portion53to the edge portion555is smaller than the height Hs from the upper surface of the second resin portion53to the upper surface of the third resin portion55(H5>H6).

As illustrated inFIG. 6, this edge portion555is continuously formed along the horizontal direction over the entire region of three end faces552defining the second opening portion551. Further, also in a part at which two end faces552and552are connected to each other, the edge portion555is continuously formed.

As illustrated inFIG. 5, the lower side face553is positioned at the lower side (a side close to the second resin portion53) with respect to the edge portion535. The lower side face553includes a curved portion5531that approaches the edge portion555as being separated from the second resin portion53and is curved toward the inner side of the convex portion556. As illustrated inFIG. 7, the curved portion5531includes: a third part5531aclose to the edge portion555; and a fourth part5531bthat is far from the edge portion555, and a curvature radius of the curved portion5531varies in these third part5531aand fourth part5531b.Specifically, the curvature radius of the third part5531ais smaller than the curvature radius of the fourth part5531b.Since the curved portion5531and the curved portion5331are slightly different in terms of the shape but have the same basic configuration, the curved portion5331is illustrated inFIG. 7, and the curved portion5531is denoted by the symbol corresponding the symbol in parentheses, so that illustrating of the curved portion5331in the drawing is omitted.

As illustrated inFIG. 5, the upper side face554is positioned at the upper side with respect to the lower side face553and the edge portion555(a side far away from the second resin portion53). The upper side face554extends in a direction different form that of the lower side face553, and in one or more embodiments, the upper side face554is an inclined face that is inclined to be separated from the edge portion535as being separated from the second resin portion53.

As illustrated inFIG. 5, in the region of the second opening portion551, the tip end of the second branch portion602and the end face552of the second opening portion551are separated from each other, and according to this, a gap92is formed between the second branch portion602and the end face552. In the gap92, a part of the second terminal portion543is exposed from the second branch portion602, the conductive bonding portion70, and the third resin portion55.

In the region of the second opening portion551including at least the gap92, the sealing resin80is filled. The second terminal portion543exposed from the second branch portion602, the conductive bonding portion70, and the third resin portion55is covered with the sealing resin80.

This sealing resin80is in contact with the second lower side face553and the edge portion555in an interface with the end face552of the second opening portion551, but the sealing resin80is not in contact with the upper side face554. That is, spreading to a height direction of the sealing resin80in the interface with the end face552extends to the position of the edge portion555.

Meanwhile, the sealing resin80spreads on the upper surface of the second branch portion602along the extending direction of the second branch portion602. In this way, by the sealing resin80covering the vicinity of the tip end of the second branch portion602, reliability of connection strength between the first wiring body50and the second wiring body60is improved.

In one or more embodiments, in the connection part of the first wiring body50and the second branch portion602, a maximum height t2of the sealing resin80(a height from the upper surface of the second resin portion53to a part of the sealing resin80which most protrudes) is equal to or lower than the height Hs from the upper surface of the second resin portion53to the upper surface of the third resin portion55(H5≥t2). Therefore, the sealing resin80does not protrude to the upper side in relation to the upper surface of the third resin portion55.

Next, operations of the first wiring body50and the wiring body assembly40of one or more embodiments will be described.FIG. 8andFIG. 9are cross-sectional views for describing a method of connecting the first wiring body and the second wiring body,FIG. 10is a cross-sectional view illustrating a relation between a surface tension and a contact angle in an end face, andFIG. 11is a cross-sectional view illustrating a relation between a surface tension and a contact angle at an edge portion. When the first wiring body50and the second wiring body60are connected, since the method of connecting the first wiring body50and the first branch portion601and the method of connecting the first wiring body50and the second branch portion602are same, the description of the latter connection method is omitted, and the description of the former connection method is employed.

First, the first wiring body50in which the end face532of the first opening portion531includes the lower side face533, the upper side face534and the edge portion535is produced. As a method of forming the lower side face533, the upper side face534and the edge portion535in the end face532, the lower side face533, the upper side face534and the edge portion535may be formed by performing a masking treatment with a cover lay, a solder resist, or the like at a position at which the lower side face533, the upper side face534and the edge portion535are formed and processing the end face532. The lower side face533, the upper side face534and the edge portion535may be formed on the flat end face532by a printing method or other known method.

Next, as illustrated inFIG. 8, a conductive bonding material100such as ACF or ACP that forms the conductive bonding portion70is disposed in the first opening portion531of the first wiring body50. Then, the vicinity of the tip end of the first branch portion601and the first wiring body50are thermal-compression-bonded by a press bonding head200and a press bonding table300in a state of interposing the conductive bonding material100between the vicinity of the tip end of the first branch portion601and the first wiring body50. According to this, the first terminal portion523and the third terminal portion622are connected by the conductive bonding material100.

Next, after the first terminal portion523and the third terminal portion622are connected via the conductive bonding portion70, the sealing resin80is formed. In this step, as illustrated inFIG. 9, a liquid resin110is injected in the region of the first opening portion531by using a dispenser, and the gap91(among the first branch portion601, the conductive bonding portion70, and the end face532of the first opening portion531) is sealed with the liquid resin110.

Herein, regarding the liquid resin110at the time of injection, the position of the upper portion of the liquid resin110ascends along the end face532in proportion to the injection amount. In this case, as illustrated inFIG. 10, in a contact point P at which the upper portion of the liquid resin110and the end face532are brought into contact with each other, three phases (a solid phase (herein, the second resin portion53), a liquid phase (herein, the liquid resin110), and a gas phase) coexist, and a surface tension T between these three phases equilibrate as described in the following mathematical expression.

In the above-described Expression (1), TSVis a surface tension between the solid phase and the gas phase, TSLis a surface tension between the solid phase and the liquid phase, TLVis a surface tension between the liquid phase and the gas phase, and θ is a contact angle.

As long as the end face532is continuously formed, when the liquid resin110is additionally injected, the liquid resin110is wetted and spread toward the height direction such that the contact angle θ in the above-described Expression (1) is maintained.

Then, as illustrated inFIG. 11, when the contact point P of the upper portion of the liquid resin110and the end face532reaches the edge portion535by additionally injecting the liquid resin110, the surface tension T between the three phases equilibrates as described in the following mathematical expression.

In one or more embodiments, as described above, the angle α is a positive value, that is, a value that is larger than 0° and smaller than 180° (0<α<π). Therefore, in the above-described Expression (2), cos α is larger than −1 and smaller than 1 (−1<cos α<1). Thus, when the above-described Expression (1) and the above-described Expression (2) are compared, cos θ in the above-described Expression (2) is a smaller value than cos θ in the above-described Expression (1). That is, in a state in which the upper portion of the liquid resin110reaches the edge portion535, the contact angle θ becomes larger as compared to a state in which the liquid resin110is in contact with the end face532until the liquid resin110reaches the edge portion535. According to this, at the edge portion535, wetting and spreading of the liquid resin110to the height direction is limited.

Then, when injection of the liquid resin110is completed, a curing treatment of the liquid resin110is performed. According to this, the sealing resin80is formed. In this case, wetting and spreading of the liquid resin110to the height direction at the time of injection is limited by the edge portion535so that, in the interface with the end face532, the sealing resin80is in contact with the lower side face533and the edge portion535but is not in contact with the upper side face534. That is, spreading of the sealing resin80to the height direction in the interface with the end face532extends to the position of the edge portion535.

As described above, in one or more embodiments, the end face532of the second resin portion53which defines the first opening portion531includes: the lower side face533; the upper side face534; and the edge portion535that connects the lower side face533and the upper side face534. According to this, spreading of the liquid resin110to the height direction in the interface with the end face532is limited by the surface tension acting at the edge portion535. As a result, it is possible to suppress that the sealing resin80is wetted and spreads on the upper surface of the third resin portion55so that flatness of the entire first wiring body50is impaired. In one or more embodiments, the upper surface of the third resin portion55is overlapped with the cover panel20, but in this case, by limiting wetting and spreading of the liquid resin110on the upper surface of the third resin portion55, excellent bonding property between the upper surface of the third resin portion55and the cover panel20can be secured.

Further, in one or more embodiments, the edge portion535is continuously formed along the horizontal direction over the entire region of the end face532. In this case, the edge portion535extends in a direction perpendicular to a flow direction of the liquid resin110, and thus spreading of the liquid resin110to the height direction in the interface with the end face532can be evenly limited. According to this, it is possible to more reliably suppress that the liquid resin110at the time of injection flows onto the upper surface of the third resin portion55.

Further, in one or more embodiments, by the edge portion535protruding toward the region of the first opening portion531, the convex portion536is formed in the end face532, and the lower side face533includes the curved portion5331that approaches the edge portion535as being separated from the first resin portion51and is curved toward the inner side of the convex portion536. In this case, in the interface with the end face532, the liquid resin110is easily guided smoothly toward the edge portion535. Further, in one or more embodiments, in this curved portion5331, the curvature radius of the first part5331aclose to the edge portion535is relatively smaller than the curvature radius of the second part5331bfar from the edge portion535. In this case, since the edge portion535can be formed in a precipitous shape, the surface tension acting at the edge portion535can be further increased. According to this, it is possible to more reliably suppress that the liquid resin110at the time of injection flows onto the upper surface of the third resin portion55.

According to one or more embodiments, the “wiring body assembly40” corresponds to an example of the “wiring body assembly”, the “first wiring body50” corresponds to an example of the “first wiring body”, the “second wiring body60” corresponds to an example of the “second wiring body”, and the “conductive bonding portion70” corresponds to an example of the “conductive bonding portion”.

According to one or more embodiments where the “first resin portion51” is regarded as an example of the “first insulating portion” (first insulator), the “first conductive portion52” corresponds to an example of the “conductive portion” (conductor), the “first terminal portion523” corresponds to an example of the “terminal portion” (terminal), the “second resin portion53” corresponds to an example of the “second insulating portion” (second insulator), the “first opening portion531” corresponds to an example of the “opening portion”, the “end face532” corresponds to an example of the “end face of the opening portion”, the “lower side face533” corresponds to an example of the “first face”, the “curved portion5331” corresponds to an example of the “curved portion”, the “first part5331a” corresponds to an example of the “first part” (first curve), the “second part5331b” corresponds to an example of the “second part” (second curve), the “upper side face534” corresponds to an example of the “second face”, the “edge portion535” corresponds to an example of the “edge portion” (edge), the “substrate61” corresponds to an example of the “substrate”, and the “third terminal portion622” corresponds to an example of the “connection terminal portion” (connection terminal).

According to one or more embodiments where the “second resin portion53” is regarded as an example of the “first insulating portion”, the “second conductive portion54” corresponds to an example of the “conductive portion”, the “second terminal portion543” corresponds to an example of the “terminal portion”, the “third resin portion55” corresponds to an example of the “second insulating portion”, the “second opening portion551” corresponds to an example of the “opening portion”, the “end face552” corresponds to an example of the “end face of the opening portion”, the “lower side face553” corresponds to an example of the “first face”, the “curved portion5531” corresponds to an example of the “curved portion”, the “third part5531a” corresponds to an example of the “first part”, the “fourth part5531b” corresponds to an example of the “second part”, the “upper side face554” corresponds to an example of the “second face”, the “edge portion555” corresponds to an example of the “edge portion”, the “substrate61” corresponds to an example of the “substrate”, and the “fourth terminal portion632” corresponds to an example of the “connection terminal portion”.

FIG. 12is a cross-sectional view illustrating a connection part of a first wiring body and a second wiring body according to one or more embodiments of the invention in an enlarged manner. The same configurations as the aforementioned embodiments are denoted by the same symbols, the repeated description is omitted by referring the description in the aforementioned embodiments.

As illustrated inFIG. 12, in a wiring body assembly40B according to one or more embodiments, a protrusion portion5332(protrusion) protruding toward a region of the opening portion531is formed at a lower end of a lower side face533B. A lower face of the protrusion portion5332covers the upper surface of the first resin portion51and the first terminal portion523. The upper surface of the protrusion portion5332faces the gap91and is inclined to approach the first resin portion51as being separated from the end face532.

In one or more embodiments, since the protrusion portion5332is formed at the lower end of the lower side face533B, a contact area of the second resin portion53and the first resin portion51and a contact area of the second resin portion53and the first terminal portion523can be increased. Further, since a level difference between the end face532and the upper surface of the first resin portion51can be formed in a smooth shape, convergence of stress to the level difference can be suppressed. According to this, peeling of the second resin portion53from the first resin portion51and the first terminal portion523can be suppressed.

FIG. 13is a cross-sectional view illustrating a connection part of a first wiring body and a second wiring body according to one or more embodiments of the invention in an enlarged manner. The same configurations as the aforementioned embodiments are denoted by the same symbols, the repeated description is omitted by referring the description in the aforementioned embodiments.

As illustrated inFIG. 13, in a wiring body assembly40C according to one or more embodiments, a sealing resin80C collectively covers both the connection part of the first opening portion531and the first branch portion601and the connection part of the second opening portion551and the second branch portion602.

In this case, the first branch portion601and the end face552of the third resin portion55are separated from each other, and according to this, a gap91C is formed between the first branch portion601and the end face552. In the gap91C, a part of the first terminal portion523is exposed from the first branch portion601, the conductive bonding portion70, and the second resin portion53. The gap91C is filled with the sealing resin80C, and the first terminal portion523exposed from the first branch portion601, the conductive bonding portion70and the second resin portion53is covered with the sealing resin80C.

This sealing resin80C is in contact with the lower side face553and the edge portion555in the interface with the end face552of the third resin portion55which defines the second opening portion551, but the sealing resin80C is not in contact with the upper side face554. That is, spreading to a height direction of the sealing resin80C in the interface with the end face552extends to the position of the edge portion555.

In this way, in a case where a plurality of edge portions exist in the height direction of the first wiring body50, if spreading to a height direction of the liquid resin110at the time of injection can be limited in the edge portion positioned at the side close to the upper surface of the third resin portion55(in one or more embodiments, the edge portion555), wetting and spreading of the liquid resin110to the upper surface of the third resin portion55can be suppressed.

FIG. 14is a cross-sectional view illustrating a connection part of a first wiring body and a second wiring body according to one or more embodiments of the invention in an enlarged manner. The same configurations as the aforementioned embodiments are denoted by the same symbols, the repeated description is omitted by referring the description in the aforementioned embodiments.

As illustrated inFIG. 14, in a wiring body assembly40D according to one or more embodiments, a concave groove portion537is formed in the end face532. In one or more embodiments, a lower side face533D is positioned at the lower side with respect to the groove portion537and extends along the height direction of the first wiring body50. Further, an upper side face534D extends along the wall face of the groove portion537. Further, a edge portion535D connecting faces of the lower side face533D and the upper side face534D is formed between the lower side face533D and the upper side face534D.

As in one or more embodiments, even when the edge portion535D does not protrude to the region of the opening portion531, spreading to the height direction of the sealing resin80can be limited by causing the surface tension to act on the edge portion535D. According to this, it can be suppressed that the sealing resin80is wetted and spreads on the upper surface of the third resin portion55so that flatness of the entire first wiring body50is impaired.

The above-described embodiments are used to facilitate the understanding of the invention and does not limit the invention. Thus, the components disclosed in the above-described embodiments include all modifications in design and equivalents belonging to the technical scope of the invention.

For example, the touch sensor of the aforementioned embodiments is a touch sensor corresponding to a projection-type capacitive sensing method using two layers of the conductive portions52and54. However, the invention is not limited thereto, and one or more embodiments of the invention are also applicable to a touch sensor corresponding to a surface-type (capacitive coupling-type) capacitive sensing method using one layer of the conductive portion.

Further, a material obtained by mixing a metal material and a carbon-based material may be used in the first conductive portion52and the second conductive portion54. In this case, for example, the carbon-based material may be disposed at a top surface side of a conductor pattern, and the metal material may be disposed at a contact surface side. Reversely, the metal material may be disposed at the top surface side of a conductor pattern, and the carbon-based material may be disposed at the contact surface side.

Further, although not particularly illustrated in the drawing, embodiments of the present invention are not particularly limited to a mode in which the first wiring body50is pasted to the cover panel20in the aforementioned embodiments. For example, the first wiring body may be configured in a mode in which a release sheet is provided on a lower surface of the first resin portion51and the first wiring body is mounted by peeling off the release sheet and bonding the first wiring body to a mounting target (such as a film, surface glass, a polarizing plate, or display glass) at the time of mounting. Further, it is possible to employ a mode in which a resin portion covering the first wiring body50from the first resin portion51(resin portion) side is further provided, and the first wiring body is mounted by being bonded to the aforementioned mounting target through the resin portion. In these cases, the mounting target on which the wiring body is mounted corresponds to an example of a support body of one or more embodiments of the invention.

Further, the wiring body and the wiring body assembly of the embodiments described above have been described as being used in the touch sensor or the like, but is not particularly limited thereto. For example, the first wiring body may be used as a heater by energizing the first wiring body to generate heat by resistance heating or the like. In one or more embodiments, a carbon-based material having a relatively high electrical resistance value is used as the conductive particles of the conductive portion. In addition, a part of the conductive portion of the first wiring body is grounded, and thus the first wiring body may be used as an electromagnetic shielding shield. Moreover, the first wiring body may be used as an antenna. In these case, the mounting target on which the first wiring body is mounted corresponds to an example of the support body of one or more embodiments of the invention.

EXPLANATIONS OF LETTERS OR NUMERALS

40WIRING BODY ASSEMBLY