阅读说明：本技术 伸缩性配线板及伸缩性配线板的制造方法 (Stretchable wiring board and method for manufacturing stretchable wiring board ) 是由 小清水和敏 于 2019-03-19 设计创作，主要内容包括：本发明涉及一种伸缩性配线板(10A),其具备：热熔层(30A)、支撑于热熔层(30A)的导体部(60)、覆盖导体部(60)的至少一部分的外涂层(70),导体部(60)具有：被外涂层覆盖的配线部(61)、从外涂层(70)露出的连接部(62),连接部(62)的从外涂层(70)露出的露出面(622)与外涂层(70)的表面(702)齐平。(The present invention relates to a stretchable wiring board (10A) which is provided with: a heat-fusible layer (30A), a conductor section (60) supported by the heat-fusible layer (30A), and an overcoat layer (70) covering at least a part of the conductor section (60), wherein the conductor section (60) has: the wiring section (61) covered by the overcoat, and the connection section (62) exposed from the overcoat (70), wherein an exposed surface (622) of the connection section (62) exposed from the overcoat (70) is flush with the surface (702) of the overcoat (70).)

1. A stretchable wiring board is provided with:

a first stretchable base material;

an outer coating layer; and

a conductor part at least a part of which is interposed between the first stretchable substrate and the overcoat layer,

the conductor part has:

a wiring section covered with the overcoat layer; and

a connection portion exposed from the overcoat layer,

the exposed surface of the connecting part exposed from the outer coating is flush with the surface of the outer coating.

2. The stretchable wiring board according to claim 1,

the stretchable wiring board includes a first reinforcing member interposed between the first stretchable base material and the conductor part,

the first reinforcing member is disposed so as to overlap at least a part of the connecting portion when viewed in a thickness direction of the conductor portion.

3. The stretchable wiring board according to claim 2,

the first reinforcing member is embedded in the first stretchable base material.

4. The stretchable wiring board according to any one of claims 1 to 3,

the stretchable wiring board includes a second reinforcing member disposed so as to overlap a portion of the wiring section when viewed in a thickness direction of the conductor section.

5. The stretchable wiring board according to claim 4,

the second reinforcing member is harder than the first stretchable base material.

6. The stretchable wiring board according to claim 4 or 5,

the stretchable wiring board is provided with a plurality of the second reinforcing members, and,

the second reinforcing members are arranged at intervals along the wiring portion.

7. The stretchable wiring board according to claim 6,

which satisfies the following formula (1):

50mm≤L≤200mm…(1)

wherein L is a distance between the first reinforcing members adjacent to each other.

8. The stretchable wiring board according to any one of claims 4 to 7,

the wiring section includes a branch portion branched into a plurality of branches,

the second reinforcing member is disposed so as to overlap the branch portion when viewed in a thickness direction of the conductor portion.

9. The stretchable wiring board according to any one of claims 4 to 8,

the second reinforcing member is embedded in the first stretchable base material.

10. The stretchable wiring board according to any one of claims 1 to 9,

the stretchable wiring board includes an undercoat layer interposed between the first stretchable base material and the conductor section.

11. The stretchable wiring board according to any one of claims 1 to 10,

the first stretch base material is a hot melt or an elastomer.

12. The stretchable wiring board according to claim 11,

the stretchable wiring board includes a fabric attached to the hot-melt material.

13. The stretchable wiring board according to any one of claims 4 to 9,

the stretchable wiring board comprises a second stretchable base material covering the outer coating layer,

the second reinforcing member is harder than the second stretchable base material.

14. A method for producing a stretchable wiring board, the method comprising the steps of:

a first step of preparing a release film;

a second step of forming the overcoat layer on the release film;

a third step of forming the connection portion of the conductor portion on the release film;

a fourth step of forming the wiring portion of the conductor portion on the overcoat layer; and

a fifth step of forming the first stretchable base material.

15. The method for manufacturing a stretchable wiring board according to claim 14,

the first stretchable base material is a hot melt,

the manufacturing method further includes:

a sixth step of attaching a fabric to the hot melt; and

and a seventh step of peeling off the release film.

Technical Field

The present invention relates to a stretchable wiring board and a method for manufacturing the stretchable wiring board.

For the designated countries that allow incorporation by reference of documents, the contents described in Japanese application No. 2018-50527 at 3/19/2018 and Japanese application No. 2018-50529 at 19/3/2018 are incorporated by reference in the present specification as a part of the description of the present specification.

Background

The wearable device and the medical device are arranged on clothes and orthoses, and sensing and monitoring are carried out by wearing the clothes and the orthoses by users. Therefore, these devices use a stretchable wiring board that can stretch and contract following the movement of the human body. As such a stretchable wiring board, a stretchable wiring board is known which includes: a sheet-like stretchable base material having stretchability; a stretchable wiring section formed on at least one side of a main surface of a stretchable base material; and an external terminal connected to the wiring portion (see, for example, patent document 1).

Disclosure of Invention

Technical problem to be solved

However, there is a problem that unevenness of the main surface of the stretchable wiring board becomes large due to a step difference generated by the wiring portion and the external terminal protruding from the main surface of the stretchable substrate, and a user of a wearable device or the like feels uncomfortable or the unevenness gets stuck.

The technical problem to be solved by the present invention is to provide a flexible wiring board having a smooth main surface.

(II) technical scheme

[1] The stretchable wiring board of the present invention is characterized by comprising: a first stretchable base material; an outer coating layer; a conductor part having at least a part thereof interposed between the hot-melt layer and the overcoat layer, the conductor part including: a wiring section covered with the overcoat layer; and a connection portion exposed from the overcoat, an exposed surface of the connection portion exposed from the overcoat being flush with a surface of the overcoat.

[2] In the above invention, the stretchable wiring board may include a first reinforcing member interposed between the first stretchable base material and the conductor part, and the first reinforcing member may be disposed so as to overlap at least a part of the connection part as viewed in a thickness direction of the conductor part.

[3] In the above invention, the first reinforcing member may be embedded in the first stretchable base material.

[4] In the above invention, the stretchable wiring board may include a second reinforcing member disposed so as to overlap a part of the wiring portion when viewed in a thickness direction of the conductor portion.

[5] In the above invention, the second reinforcing member may be harder than the first stretchable base material.

[6] In the above invention, the stretchable wiring board may include a plurality of the second reinforcing members, and the second reinforcing members may be arranged at intervals along the wiring portion.

[7] In the above invention, the following formula (1) may be satisfied:

50mm≤L≤200mm…(1)

wherein L is a distance between the first reinforcing members adjacent to each other.

[8] In the above invention, the wiring portion may include a plurality of branch portions, and the second reinforcing member may be disposed so as to overlap the branch portions when viewed in a thickness direction of the conductor portion.

[9] In the above invention, the second reinforcing member may be embedded in the first stretchable base material.

[10] In the above invention, the stretchable wiring board may include an undercoat layer interposed between the first stretchable base material and the conductor part.

[11] In the above invention, the first stretchable base material may be a hot melt or an elastomer.

[12] In the above invention, the stretchable wiring board may include a fabric to which the hot-melt material is attached.

[13] In the above invention, the stretchable wiring board may include a second stretchable base material covering the overcoat layer, and the second reinforcing member may be harder than the second stretchable base material.

[14] A method for manufacturing a stretchable wiring board according to the present invention is a method for manufacturing a stretchable wiring board, including: a first step of preparing a release film; a second step of forming the overcoat layer on the release film; a third step of forming the connection portion of the conductor portion on the release film; a fourth step of forming the wiring portion of the conductor portion on the overcoat layer; and a fifth step of forming the first stretchable base material.

[15] In the method for manufacturing a stretchable wiring board according to the present invention, the first stretchable base material may be a hot melt, and the method may further include: a sixth step of attaching a fabric to the hot melt; and a seventh step of peeling off the release film.

[16] The stretchable wiring board of the present invention is characterized by comprising: a first stretchable base material; a conductor section that includes a wiring section and a connection section connected to the wiring section, and that is provided on the first stretchable base material; and a first reinforcing member that is disposed so as to overlap a part of the wiring portion in a plan view and is harder than the first stretchable base material.

[17] In the above invention, the stretchable wiring board may include a second reinforcing member disposed so as to overlap the connection portion in a plan view.

[18] In the above invention, the stretchable wiring board may include a plurality of the first reinforcing members, and the first reinforcing members may be arranged at intervals along the wiring portion.

[19] In the above invention, the following formula (1) may be satisfied:

50mm≤L≤200mm…(1)

wherein L is a distance between the first reinforcing members adjacent to each other.

[20] In the above invention, the wiring portion may include a plurality of branch portions, and the first reinforcing member may be disposed so as to overlap the branch portions in a plan view.

[21] In the above invention, the first stretchable base material may be a hot melt or an elastomer.

[22] In the above invention, the first reinforcing member may be embedded in the hot melt or the elastic body.

[23] In the above invention, the stretchable wiring board may include an undercoat layer interposed between the first stretchable base material and the conductor part.

[24] In the above invention, the stretchable wiring board may include an undercoat layer interposed between the first stretchable base material and the conductor part.

[25] In the above invention, the stretchable wiring board may include an overcoat layer covering the wiring portion.

[26] In the above invention, the stretchable wiring board may include a second stretchable base material covering the overcoat layer, and the first reinforcing member may be harder than the second stretchable base material.

(III) advantageous effects

According to the present invention, since the exposed surface of the connecting portion is flush with the surface of the overcoat layer, unevenness of the main surface of the stretchable wiring board can be reduced.

Drawings

Fig. 1 is a perspective view showing a stretchable wiring board according to a first embodiment of the present invention.

Fig. 2 is a plan view showing the stretchable wiring board according to the first embodiment of the present invention.

Fig. 3 is a sectional view taken along the line III-III of fig. 1.

Fig. 4 is a plan view showing the stretchable base material according to the first embodiment of the present invention.

Fig. 5 (a) is a sectional view taken along line VA-VA of fig. 4, and fig. 5 (B) is a sectional view taken along line VB-VB of fig. 4.

Fig. 6 is a process diagram showing a method for manufacturing a stretchable wiring board according to the first embodiment of the present invention.

Fig. 7 (a) to (h) are cross-sectional views showing the respective steps of fig. 6.

Fig. 8 is a plan view of the stretchable wiring board according to the second embodiment of the present invention.

Fig. 9 is a sectional view taken along line IX-IX of fig. 8.

Fig. 10 is an enlarged view of the X portion of fig. 8.

Fig. 11 (a) is a sectional view taken along line XIA-XIA of fig. 10, and fig. 11 (B) is a sectional view taken along line XIB-XIB of fig. 10.

Fig. 12 is a plan view for explaining a conductor part of the stretchable wiring board according to the second embodiment of the present invention.

Fig. 13 is a process diagram showing a method for manufacturing a stretchable wiring board according to a second embodiment of the present invention.

Fig. 14 is a sectional view illustrating each step of fig. 13 (a) to 13 (h).

Fig. 15 is a sectional view of a stretchable wiring board according to a third embodiment of the present invention.

Fig. 16 is a sectional view of a stretchable wiring board according to a fourth embodiment of the present invention.

Fig. 17 is a sectional view of a stretchable wiring board according to a fifth embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

< first embodiment >

Fig. 1 is a perspective view showing a stretchable wiring board of the present embodiment, fig. 2 is a plan view showing the stretchable wiring board of the present embodiment, fig. 3 is a sectional view taken along line III-III, fig. 4 is a plan view showing a stretchable base material of the present embodiment, fig. 5 (a) is a sectional view taken along line VA-VA of fig. 4, and fig. 5 (B) is a sectional view taken along line VB-VB of fig. 4.

The stretchable wiring board 10A shown in fig. 1 and 2 is used, for example, in a wearable device such as a biosensor, or a position where stretchability is required in a medical device such as a biological information monitor, since the wearable device and the medical device are provided on clothing or an orthosis, the stretchable wiring board 10A needs to sufficiently follow the curvature of a human body, and further, the use of the stretchable wiring board 10A is not particularly limited as long as stretchability is required.

As shown in the cross-sectional view of fig. 3, the stretchable wiring board 10A of the present embodiment includes: a fabric 20, a hot melt layer 30A, a first reinforcing member 40A, a primer layer 50, a conductor part 60, and an overcoat layer 70. The "stretchable wiring board 10A" in the present embodiment corresponds to an example of the "stretchable wiring board" in the present invention, the "woven fabric 20" in the present embodiment corresponds to an example of the "woven fabric" in the present invention, the "hot-melt layer 30A" in the present embodiment corresponds to an example of the "first stretchable base material" in the present invention, the "first reinforcing member 40A" in the present embodiment corresponds to an example of the "first reinforcing member" in the present invention, the "undercoat layer 50" in the present embodiment corresponds to an example of the "undercoat layer" in the present invention, the "conductor section 60" in the present embodiment corresponds to an example of the "conductor section" in the present invention, and the "overcoat layer 70" in the present embodiment corresponds to an example of the "overcoat layer" in the present invention.

The fabric 20 is a target to which the hot-melt layer 30A is bonded, and is a fabric portion of a garment or an orthosis provided with a wearable device or the like. The fabric 20 is a woven fabric (cloth) made of a plurality of fibers, and more specifically, as shown in fig. 4, is made of a first fiber bundle 21 and a second fiber bundle 22 that intersect with each other. In fig. 4, only the stretchable base material portion composed of the fabric 20 and the hot-melt layer 30A is extracted and shown. The first fiber bundle 21 is formed by collecting one or two or more first fibers 211. The first fiber bundle 21 is inclined in a direction D with respect to a direction Y in the figure (a predetermined expansion/contraction direction of the stretchable wiring board 10A)₁(hereinafter also referred to as first direction D)₁) Upper extensionA plurality of first fiber bundles 21 in a direction opposite to the first direction D₁Direction of crossing D₂(hereinafter also referred to as second direction D)₂) Are arranged in an upper row. The second fiber bundle 22 is formed by collecting one or two or more second fibers 221. The second fiber bundle 22 is in the second direction D₂Extend upward, and a plurality of second fiber bundles 22 extend in a first direction D₁Are arranged in an upper row. The fabric 20 is configured by interweaving a plurality of first fiber bundles 21 and a plurality of second fiber bundles 22 with each other in a plan view.

As the first fibers 211 and the second fibers 221, for example, rayon, nylon, polyester, acrylic, polyurethane, vinylon, polyethylene, Nafion (registered trademark), aramid, cotton, or the like can be used. The first fibers 211 and the second fibers 221 may have elasticity. The first fibers 211 and the second fibers 221 may be the same as or different from each other. The number of the first fibers 211 and the number of the second fibers 221 may be the same as or different from each other.

In a plan view, a rectangular gap 23 is formed between the first fiber bundle 21 and the second fiber bundle 22 which intersect with each other. The gap 23 is defined by the first fiber bundles 21, 21 adjacent to each other and the second fiber bundles 22, 22 adjacent to each other in a top view.

The gap 23 is open to one main surface 201 of the fabric 20 and to the other main surface 202 (see fig. 5 a and 5B) of the fabric 20, and communicates the one main surface 201 and the other main surface 202 of the fabric 20. The gap 23 may not extend straight in the thickness direction of the fabric 20, and may be open to the two main surfaces 201 and 202 to communicate the two main surfaces 201 and 202. The gaps 23 are deformed by the deformation of the stretchable wiring board 10A, and the fabric 20 as a whole exhibits stretchability.

Further, the Young's modulus E of the fabric 20_fPreferably 0.1-35 MPa (0.1MPa ≤ E)_fLess than or equal to 35 MPa). In addition, elongation at break B of the fabric 20_fPreferably 50% or more (B)_fMore than or equal to 50 percent). The "elongation at break" refers to the elongation of the material to the breaking point with respect to the natural length. In addition, the thickness T of the fabric 20 is_fPreferably 20 to 300μm(20μm≤T_f≤300μm)。

In fig. 1 to 4, the overall shape of the fabric 20 is rectangular, but the shape is not particularly limited thereto. The overall shape of the fabric 20 may vary depending on the shape of the garment, orthosis, on which the wearable device is provided.

As shown in fig. 3, the hot melt layer 30A is adhered to the main surface 201 of the fabric 20 and formed on the fabric 20. As shown in fig. 5 (a) and 5 (B), the hot melt layer 30A is in close contact with the first fibers 211 and the second fibers 221 located on the main surface 201 of the fabric 20, enters between the first fibers 211 constituting one first fiber bundle 21, and enters between the second fibers 221 constituting one second fiber bundle 22. The hot melt layer 30A is slightly impregnated in the vicinity of the surfaces of the first fibers 211 and the second fibers 221 which are in contact with each other, but is not impregnated into the first fibers 211 and the second fibers 221. That is, in the present embodiment, the hot-melt layer 30A is not completely impregnated into the first fibers 211 and the second fibers 221.

The hot melt layer 30A is formed in a bridge shape between the first fiber bundles 21 adjacent to each other via the gap 23. Similarly, the hot melt layer 30A is formed in a bridge shape between the second fiber bundles 22 adjacent to each other via the gap 23. Thereby, the hot melt layer 30A covers the gap 23 opened to the main surface 201 of the fabric 20. The hot melt layer 30A does not enter the inside of the gap 23, and the inside of the gap 23 is not filled with the hot melt layer 30A. Note that, the hot melt layer 30A may slightly enter the inside of the gap 23 in the vicinity of the opening of the gap 23 as long as the inside of the gap 23 is not filled with the hot melt layer.

The hot-melt layer 30A has elasticity, and as a constituent material thereof, a hot-melt resin material such as polyester, polyurethane, acrylic, styrene-butadiene rubber, or silicon can be used.

Returning to fig. 3, the first reinforcing member 40A is located between the hot melt layer 30A and the undercoat layer 50, and in the present embodiment, is embedded in the hot melt layer 30A. The conductor portion 60 is positioned above the first reinforcing member 40A via the undercoat layer 50. In other words, the first reinforcing member 40A is interposed between the heat fusion layer 30A and the conductor portion 60. The connection portion 62 of the present embodiment corresponds to a "connection portion" of the present invention.

The first reinforcing member 40A is disposed so as to overlap the connection portion 62 as viewed in the thickness direction of the conductor portion 60 (the Z direction in the drawing, and also the thickness direction of the stretchable wiring board 10A). The first reinforcing member 40A thus configured particularly reinforces the connecting portion 62. Although stress is easily applied to the connection portion 62 by connection to an external device or the like, the connection portion 62 can be prevented from being damaged by reinforcement with the first reinforcement member 40A. Since first reinforcing member 40A is embedded in hot-melt layer 30A, even if first reinforcing member 40A is disposed, no step is generated in flexible wiring board 10A, and therefore smoothness of both main surfaces of flexible wiring board 10A can be improved. Further, the first reinforcing member 40A is interposed between the heat-fusible layer 30A and the conductor portion 60, and the first reinforcing member 40A is disposed at a position close to the conductor portion 60, so that the connection portion 62 can be reliably reinforced.

The first reinforcing member 40A is not particularly limited, and for example, an adhesive tape or the like can be used. The adhesive tape is not particularly limited, and for example, an adhesive tape having an acrylic adhesive layer on the main surface of a polyester film may be used, and the first reinforcing member 40A may be disposed by attaching the acrylic adhesive layer to the primer layer 50.

The primer layer 50 is provided on the hot melt layer 30A and the first reinforcing member 40A, and is interposed between the hot melt layer 30A and the conductor portion 60. The undercoat layer 50 covers the lower surface 601 and the side surface 602 of the conductor portion 60, and the planar shape of the undercoat layer 50 is substantially the same as the planar shape of the conductor portion 60. Further, the undercoat layer 50 has stretchability, as in the case of the fabric 20 and the like.

When stretchable wiring board 10A is stretched, undercoat layer 50 functions as a buffer layer that prevents conductor part 60 from breaking, and also functions as a waterproof layer. Examples of the material constituting such a primer layer 50 include polyester resin, polyurethane resin, acrylic resin, and silicone resin.

Young's modulus E of undercoat layer 50_pPreferably the Young's modulus E of the fabric 20_fThe following (E)_p≤E_f) From the viewpoint of improving the function as a relaxation layer between the woven fabric 20 and the conductor portion 60, the Young's modulus E of the woven fabric 20 is more preferably higher than that of the woven fabric 20_fLow (E)_p＜E_f). Young's modulus E as such an undercoat layer 50_pPreferably 0.1 to 10MPa (0.1 MPa. ltoreq. E)_pLess than or equal to 10 MPa). Further, elongation at break B as the undercoat layer 50_pPreferably 50% or more (B)_pMore than or equal to 50 percent). Further, the thickness T of the undercoat layer 50 is_PPreferably 10 to 50 μm (10 μm. ltoreq. T)_P≤50μm)。

The conductor part 60 includes: a wiring portion 61 provided on the undercoat layer 50 and covered with the overcoat layer 70; and a connection portion 62 exposed to the outside from the overcoat 70. That is, the wiring section 61 as a part of the conductor section 60 is interposed between the heat-fusible layer 30A and the overcoat layer 70. The "wiring section 61" in the present embodiment corresponds to the "wiring section" in the present invention, and the "connecting section 62" in the present embodiment corresponds to the "connecting section" in the present invention.

The wiring section 61 is formed integrally with the connection section 62, and electrically connects the plurality of connection sections 62 to each other. In the present embodiment, the wiring portion 61 has a planar shape of a single strip as shown in fig. 1 and 2, but is not limited thereto. For example, the wiring portion 61 may have an arbitrary pattern such as a branched planar shape according to the use of the stretchable wiring board 10A.

The connection portion 62 has a convex protrusion 621 protruding in a direction away from the hot melt layer 30A, and an exposed surface 622 of the protrusion 621 is exposed from the overcoat layer 70. The "exposed surface 622" in the present embodiment corresponds to the "exposed surface" in the present invention.

The connection portion 62 is not particularly limited, and can be used as a connection terminal for connecting to an electronic device, and ensures electrical conduction with the electronic device on the exposed surface 622. In the present embodiment, the embodiment has been described as an example in which two connection portions 62 are provided, but the present invention is not limited to this, and three or more connection portions 62 may be provided depending on the application of the stretchable wiring board 10A.

The conductor part 60 is formed by dispersing conductive particles in a binder, and has elasticity. Here, the elastic property is imparted to the conductor portion 60 by making the adhesive contained in the conductor portion 60 of a material having elastic properties, and as such an adhesive, an elastomer is preferably used, and for example, acrylic rubber, urethane rubber, nitrile rubber, silicone rubber, fluororubber, a composite of two or more of these, or the like can be used. As the conductive particles, a metal material made of a metal such as gold, silver, platinum, ruthenium, lead, tin, zinc, or bismuth, or an alloy thereof, or a non-metal material such as carbon can be used. The shape of the conductive particles is preferably a scaly or amorphous shape.

The kind of the conductive particles contained in the protrusion 621 and the kind of the conductive particles contained in the wiring portion 61 may be different depending on the application of the stretchable wiring board 10A. For example, although not particularly limited, carbon may be used as the conductive particles included in the protrusion 621, and silver may be used as the conductive particles included in the wiring portion 61.

Young's modulus E of the conductor part 60_cMay be larger than the Young's modulus E of the fabric 20_fHigh (E)_c＞E_f) The Young's modulus E of the fabric 20 may be larger than_fLow (E)_c＜E_f) And possibly also the Young's modulus E of the fabric 20_fSame (E)_c＝E_f). In particular, the Young's modulus E of the conductor portion 60_cPreferably, the Young's modulus E of the fabric 20_fHigh (E)_c＞E_f). Young's modulus E of such a conductor part 60_cPreferably 10 to 200MPa (10 MPa. ltoreq. E)_c200MPa or less), and further, as the maximum elongation L E of the conductor part 60_cPreferably 5-50% (5% ≦ L E)_cLess than or equal to 50 percent). The elongation at break B of the conductor part 60_cPreferably 10 to 100% (10% ≦ B)_c≤100％)。

The overcoat layer 70 is provided on the conductor portion 60 and the undercoat layer 50, and covers at least a part of the conductor portion 60, thereby protecting the conductor portion 60. Specifically, the upper surface of the wiring portion 61 and the side surface of the protruding portion 621 are covered with the overcoat layer 70. The overcoat layer 70 has a hole 701 penetrating from one main surface to the other main surface, and a protrusion 621 is formed inside the hole 701.

In addition, the surface 702 of the overcoat 70 (the main surface of the overcoat 70 not in contact with the conductor part 60) is flush with the exposed surface 622 of the connection part 62. The term "flush" in the present invention means that the surface 702 of the overcoat 70 and the exposed surface 622 of the connection portion 62 are on the same plane, or the size D of the step difference is 5 μm or less (0 μm. ltoreq. D. ltoreq.5 μm). In particular, it is more preferable that the size D of the step difference is 1 μm or less (0 μm. ltoreq. D.ltoreq.1 μm).

Like fabric 20, overcoat 70 preferably has stretch properties. Examples of the material constituting the overcoat layer 70 include polyester, polyurethane, acrylic, and silicon.

Young's modulus E as overcoat 70_oPreferably, E is smaller than that of the undercoat layer 50_pHigh (E)_o＞E_p) More preferably, the Young's modulus E of the conductor 60 is larger than that of the conductor_cLow (E)_o＜E_c). Young's modulus E as such overcoat layer 70_oPreferably 5 to 100MPa (5 MPa. ltoreq. E)_o100MPa or less), and, in addition, as the maximum elongation L E of the overcoat layer 70_oPreferably 10-50% (10% ≦ L E)_oLess than or equal to 50 percent). Further, elongation at break B as overcoat 70_oPreferably 50% or more (B)_oMore than or equal to 50 percent). In addition, the thickness T of the overcoat layer 70 is_oPreferably 10 to 20 μm (10 μm. ltoreq. T)_o≤20μm)。

The material constituting the overcoat layer 70 and the material constituting the undercoat layer 50 are preferably substantially the same material. In this case, the interface of the undercoat layer 50 and the overcoat layer 70 is only slightly visible, and the undercoat layer 50 is substantially integral with the overcoat layer 70.

In order to improve the water resistance, a stretchable base material (not shown) may be attached to the overcoat layer 70 so as to cover the boundary portion between the overcoat layer 70 and the connection portion 62. As the stretchable base material, a resin material can be used, and the resin material preferably has water repellency. The resin material having water repellency is not particularly limited, and a joint tape can be used. Further, a release film 80 (see fig. 7 (g)) described later may be attached to the overcoat layer 70.

The above-described stretchable wiring board 10A of the present embodiment achieves the following effects.

In the stretchable wiring board 10A of the present embodiment, since the surface 702 of the overcoat 70 is flush with the exposed surface 622 of the connecting portion 62, it is possible to reduce the irregularities on the surface of the stretchable wiring board 10A to such an extent that the user does not feel uncomfortable in a wearable device or the like.

The hot-melt layer 30A is heated when it is stuck to the fabric 20, and the like, thereby exhibiting fluidity. Due to the fluidity of the hot-melt layer 30A, the unevenness on the surface of the fabric 20 can be absorbed, and the step between the undercoat layer 50 and the first reinforcing member 40A can also be absorbed, so that the unevenness of the entire stretchable wiring board 10A can be reduced.

Next, a method for manufacturing the stretchable wiring board according to the present embodiment will be described with reference to fig. 6 and 7 (a) to 7 (h). Fig. 6 is a process diagram for explaining a method of manufacturing the stretchable wiring board according to the present embodiment. Fig. 7 (a) to 7 (h) are views showing the respective steps of fig. 6, and specifically, fig. 7 (a) is a cross-sectional view explaining a step of preparing a release film, fig. 7 (b) is a cross-sectional view explaining a step of forming an overcoat layer, fig. 7 (c) is a cross-sectional view explaining a step of forming a conductor portion, fig. 7 (d) is a cross-sectional view explaining a step of forming a primer layer, fig. 7 (e) is a cross-sectional view explaining a step of disposing a first reinforcing member, fig. 7 (f) is a cross-sectional view explaining a step of forming a thermally fusible layer, fig. 7 (g) is a cross-sectional view explaining a step of attaching a fabric, and fig. 7 (h) is a cross-sectional view explaining a step of peeling off the release film.

As shown in fig. 6, the method for manufacturing a stretchable wiring board according to the present embodiment includes: a step of preparing a release film (step S1), a step of forming a topcoat (step S2), a step of forming a conductor part (step S3), a step of forming a primer (step S4), a step of disposing a first reinforcing member (step S5), a step of forming a hot melt layer (step S6), a step of attaching a fabric (step S7), and a step of peeling the release film (step S8).

First, in step S1 of fig. 6, as shown in fig. 7 (a), a release film 80 is prepared. The release film 80 is a resin film subjected to a release treatment, and although not particularly limited, for example, a release-treated PET film can be used as the release film 80. Step S1 in the present embodiment corresponds to the "first step" of the present invention.

Next, in step S2 of fig. 6, as shown in fig. 7 (b), the overcoat layer 70 of a predetermined pattern is formed on one main surface of the release film 80. Here, the hole 701 in which the overcoat layer 70 is not formed on the release film 80 is also formed at the same time. The overcoat layer 70 is formed by applying a material constituting the overcoat layer 70 on the release film 80 and curing the material. As the coating method, various coating methods such as a screen printing method, a spray coating method, a bar coating method, a dip coating method, an ink jet method, and the like can be employed. As a curing method, irradiation with energy rays such as ultraviolet rays or infrared laser beams, heating, cooling, drying, and the like can be used. Step S2 in the present embodiment corresponds to the "second step" of the present invention.

Next, in step S3 of fig. 6, the conductor part 60 is formed as shown in fig. 7 (c). At this time, the connection part 62 is formed inside the hole 701, and the wiring part 61 is formed on the overcoat layer 70. The conductor portion 60 is formed by applying a conductive paste to the inside of the hole 701 and the overcoat layer 70 and curing the paste. As a specific example of the conductive paste forming the conductor part 60, a conductive paste in which conductive particles, a binder, water or a solvent, and various additives are mixed can be exemplified. Examples of the solvent contained in the conductive paste include ethylene glycol butyl ether acetate, carbitol acetate, butyl carbitol acetate, dipropylene glycol monobutyl ether, diethylene glycol monoethyl ether, cyclohexanone, isophorone, and terpineol. The coating method and the curing method can be the same as those used for forming the overcoat layer 70. Step S3 in the present embodiment corresponds to the "third step of forming a connection portion on a release film" and the "fourth step of forming a wiring portion on an overcoat" in the present invention. As described above, in the present embodiment, "third step" and "fourth step" of the present invention are performed simultaneously.

Next, in step S4 of fig. 6, as shown in fig. 7 (d), the undercoat layer 50 is formed on the conductor portion 60. The undercoat layer 50 is formed by applying the resin material described above to the conductor portion 60 and curing it. The coating method and the curing method can be the same as those used for forming the overcoat layer 70.

Next, in step S5 of fig. 6, as shown in fig. 7 (e), the first reinforcing member 40A is disposed on the undercoat layer 50. The first reinforcing member 40A is disposed at a position overlapping the connection portion 62 when viewed in the thickness direction of the conductor portion 60. Although not particularly limited, specifically, the first reinforcing member 40A is formed by using the adhesive tape described above and bonding the adhesive layer of the adhesive tape to the primer layer 50.

Next, in step S6 of fig. 6, as shown in fig. 7 (f), a hot melt layer 30A is formed on the first reinforcing member 40A and the undercoat layer 50. The hot-melt layer 30A can be formed by disposing the above-described thermoplastic hot-melt adhesive on the first reinforcing member 40A and the primer layer 50. In this case, the hot melt adhesive may be heated to be molded into an arbitrary shape. As the adhesive, a sheet-like hot-melt adhesive can be used. Step S6 in the present embodiment corresponds to the "fifth step" of the present invention.

Next, in step S7 of fig. 6, as shown in fig. 7 (g), the fabric 20 is stuck to the hot-melt layer 30A. Although not particularly limited, specifically, the hot-melt layer 30A is attached to the fabric 20 in a state softened by heating. Step S7 in the present embodiment corresponds to the "sixth step" of the present invention.

Next, in step S8 in fig. 6, as shown in fig. 7 (h), release film 80 is peeled off from stretchable wiring board 10A. Step S8 in the present embodiment corresponds to the "seventh step" of the present invention. The timing of peeling the release film 80 is not limited to the timing after the pasting of the web 20. For example, the release film 80 may be peeled off after the hot melt layer 30A is formed (after step S6 of fig. 6) and before the web 20 is pasted (before step S7 of fig. 6).

According to the method for producing the stretchable wiring board 10A of the present embodiment, since the smooth surface shape of the release film 80 is transferred to the exposed surface 622 of the connecting portion 62 and the surface 702 of the overcoat 70, the surfaces thereof are smooth, and the occurrence of a step (flush) at the boundary therebetween can be suppressed. As a result, the irregularities on the surface of the stretchable wiring board 10A can be reduced to such an extent that the user does not feel uncomfortable.

< second embodiment >

Fig. 8 is a plan view of the stretchable wiring board according to the first embodiment of the present invention, fig. 9 is a sectional view taken along line IX-IX of fig. 8, fig. 10 is an enlarged view of portion X of fig. 8, fig. 11 (a) is a sectional view taken along line XIA-XIA of fig. 10, (B) of fig. 11 is a sectional view taken along line XIB-XIB of fig. 10, and fig. 12 is a plan view for explaining a conductor part of the stretchable wiring board. In fig. 10, the hot melt layer 30A, the undercoat layer 50, the conductor portion 60, and the overcoat layer 70 are shown by broken lines for convenience. Although fig. 8 shows electronic component 200 mounted on connection portion 62, fig. 9 and 12 do not show electronic component 200 mounted on connection portion 62 for convenience.

As in the first embodiment, the stretchable wiring board 10B shown in fig. 8 and 9 is used in a position where stretchability is required in a wearable device such as a biosensor, or a medical device such as a biological information monitor, for example, since the wearable device or the medical device is provided in clothing or an orthosis, the stretchable wiring board 10B needs to sufficiently follow the curvature of a human body, for example, as shown in fig. 8, an electronic component 200 is provided on the stretchable wiring board 10B, a pressure-sensitive sensor, a silver/silver chloride electrode, or the like is formed as the electronic component 200, or a mounting component such as an IC, a capacitor, or L ED is mounted, and the use of the stretchable wiring board 10B is not particularly limited as long as stretchability is required.

As shown in fig. 8 and 9, the stretchable wiring board 10B of the present embodiment includes: fabric 20, hot melt layer 30A, first reinforcing component 40A, second reinforcing component 40B, undercoat layer 50, conductor section 60, and overcoat layer 70. The "stretchable wiring board 10B" in the present embodiment corresponds to an example of the "stretchable wiring board" in the present invention, the "woven fabric 20" in the present embodiment corresponds to an example of the "woven fabric" in the present invention, the "hot-melt layer 30A" in the present embodiment corresponds to an example of the "first stretchable base material" in the present invention, the "first reinforcing member 40A" in the present embodiment corresponds to an example of the "first reinforcing member" in the present invention, the "second reinforcing member 40B" in the present embodiment corresponds to an example of the "second reinforcing member" in the present invention, the "undercoat layer 50" in the present embodiment corresponds to an example of the "undercoat layer" in the present invention, the "conductor portion 60" in the present embodiment corresponds to an example of the "conductor portion" in the present invention, and the "overcoat layer 70" in the present embodiment corresponds to an example of the "overcoat layer" in the present invention.

The fabric 20 is a target to which the hot-melt layer 30A is bonded, and is a fabric portion of a garment or an orthosis provided with a wearable device or the like. As in the first embodiment, the fabric 20 is a woven fabric (cloth) made of a plurality of fibers, and more specifically, as shown in an enlarged view of fig. 10, is made of a first fiber bundle 21 and a second fiber bundle 22 that intersect with each other.

In a plan view, a rectangular gap 23 is formed between the first fiber bundle 21 and the second fiber bundle 22 which intersect with each other. The gap 23 is defined by the first fiber bundles 21, 21 adjacent to each other and the second fiber bundles 22, 22 adjacent to each other in a top view.

The gap 23 is open on one main surface 201 of the fabric 20, and is open on the other main surface 202 (see fig. 11 a and 11B) of the fabric 20, and connects the one main surface 201 and the other main surface 202 of the fabric 20. The gap 23 may not extend straight in the thickness direction of the fabric 20, and may be open to the two main surfaces 201 and 202 to communicate the two main surfaces 201 and 202. The gaps 23 are deformed by the deformation of the stretchable wiring board 10B, and the fabric 20 as a whole exhibits stretchability.

As shown in fig. 11 (a) and 11 (B), the hot-melt layer 30A is bonded to the main surface 201 of the web 20 and formed on the web 20 in the same manner as in the first embodiment. The hot-melt layer 30A has elasticity, and the same material as that of the first embodiment can be used as the constituent material.

Returning to fig. 8 and 9, the first reinforcing member 40A is disposed so as to overlap the connecting portion 62 as viewed in the thickness direction of the conductor portion 60. The first reinforcing member 40A is embedded in the hot melt layer 30A and interposed between the hot melt layer 30A and the undercoat layer 50. Although stress is easily applied to the connection portion 62 by connection to an external device or the like, the connection portion 62 can be prevented from being damaged by reinforcement with the first reinforcement member 40A. Since first reinforcing member 40A is embedded in heat-fusible layer 30A, no step is generated in stretchable wiring board 10B even if first reinforcing member 40A is disposed, and therefore, smoothness of both main surfaces of stretchable wiring board 10B can be improved. Further, the first reinforcing member 40A is interposed between the heat-fusible layer 30A and the conductor portion 60, and the first reinforcing member 40A is disposed at a position close to the conductor portion 60, so that the connection portion 62 can be reliably reinforced. The connection portion 62 of the present embodiment corresponds to a "connection portion" of the present invention.

Although not particularly limited, a distance L between the first reinforcing member 40A and the second reinforcing member 40B adjacent to the first reinforcing member 40A_APreferably (see fig. 8) satisfies the following formula (1).

50mm≤L_A≤200mm…(1)

Although not particularly limited, an adhesive tape or the like can be used as the first reinforcing member 40A as in the first embodiment.

Second reinforcing member 40B (second reinforcing member 40B)₁And a second reinforcing member 40B₂) The conductor portion 60 is arranged to overlap a part of the wiring portion 61 as viewed in the thickness direction (the Z direction in the figure, and also the thickness direction of the stretchable wiring board 10B). Further, the second reinforcing member 40B is embedded in the hot melt layer 30A, and as a result, the second reinforcing member 40B is interposed between the hot melt layer 30A and the undercoat layer 50. Since the second reinforcing member 40B is embedded in the hot-melt layer 30A, even if the second reinforcing member 40B is disposed, a step does not occur in the stretchable wiring board 10B, and therefore, smoothness of both main surfaces of the stretchable wiring board 10B can be improved. The "wiring portion 61" of the present embodiment corresponds to the "wiring portion" of the present invention.

A plurality of second reinforcing members 40B are arranged so as to be separated from each other along the extending direction of the wiring portion 61. Specifically, the second reinforcing member 40B₁The second reinforcing member 40B is arranged so as to overlap with the first and second branch portions 612a, 612B branching from the wiring portion 61 into a plurality of parts when viewed in the thickness direction of the conductor portion 60, and so as to be overlapped with the second branch portions 612a, 612B₂The wiring portion 60 is arranged to overlap with a part of the wiring main body portion 611 of the wiring portion 61 as viewed in the thickness direction (in the cross-section of fig. 9)In the figure, the second reinforcing member 40B is omitted₁Second reinforcing member 40B therebetween₂). Although stress is easily concentrated on the branch portions 612a, 612B, the second reinforcing member 40B is provided by the structure₁Thereby, the durability of the branch portions 612a, 612b can be improved. In addition, the second reinforcing members 40B disposed at the branch portions 612a and 612B can be used₁Operates as a fulcrum, and thus improves the operability of the stretchable wiring board 10B. The "first branch portion 612 a" and the "second branch portion 612 b" of the present embodiment correspond to the "branch portions" of the present invention.

As a result, the second reinforcing member 40B₁、40B₂Arranged at intervals along the wiring section 61. Namely, the second reinforcing member 40B₁、40B₂The wiring portions 61 are arranged apart (with a gap) from each other. By making the second reinforcing member 40B as described above₁The arrangement of the first and second branch portions 612a and 612b can suppress breakage of the wiring portion 61 in the first and second branch portions 612a and 612 b.

Although not particularly limited, the adjacent second reinforcing members 40B₁、40B₂Distance L therebetween_B(see fig. 8) satisfies the following formula (2).

50mm≤L_B≤200mm…(2)

By making the second reinforcing members 40B adjacent to each other₁、40B₂Distance L therebetween_BWithin the above range, the flexibility of the flexible wiring board 10B can be ensured, and the rigidity can be sufficiently improved. In addition, since the stretchable wiring board 10B can be easily handled with the second reinforcing member 40B as a fulcrum, the operability of the stretchable wiring board 10B can be further improved.

The intervals between the adjacent second reinforcing members 40B may be equal intervals or irregular intervals. This interval can be appropriately selected according to the design of the stretchable wiring board 10B. In the present embodiment, the case where a plurality of first reinforcing members 40A are arranged is exemplified, but the number of second reinforcing members 40B may be one when the overall length of the stretchable wiring board 10B is relatively short, for example.

The second reinforcing member 40B may be made of the same material as the first reinforcing member 40A or a different material. Although not particularly limited, for example, when the wiring portion 61 and the connection portion 62 need to have different rigidities, the first reinforcing member 40A and the second reinforcing member 40B may be made of materials having different rigidities. The second reinforcing member 40B is made of a material harder than the hot melt layer 30A, and the young's modulus E of the second reinforcing member 40B_RBYoung's modulus E of specific heat fusion layer 30A_hLarge (E)_RB＞E_h)。

The primer layer 50 is provided on the hot melt layer 30A and the first and second reinforcing members 40A and 40B, and is interposed between the hot melt layer 30A and the conductor portion 60. The undercoat layer 50 covers the lower surface 601 and the side surface 602 of the conductor portion 60, and the planar shape of the undercoat layer 50 is substantially the same as the planar shape of the conductor portion 60. Further, the undercoat layer 50 has stretchability, as in the case of the fabric 20 and the like. The material constituting the undercoat layer 50 can be the same as that of the first embodiment.

As shown in fig. 9, the conductor portion 60 includes: a wiring portion 61 provided on the undercoat layer 50 and covered with the overcoat layer 70; and a connection portion 62 exposed to the outside from the overcoat 70. As shown in fig. 8, the conductor portion 60 has a strip-like planar shape formed by a bundle of a plurality of conductor lines (described later), and the hot-melt layer 30A, the undercoat layer 50, and the overcoat layer 70 also have a strip-like planar shape along the conductor portion 60.

The wiring portion 61 is formed integrally with the connection portion 62, thereby electrically connecting the plurality of connection portions 62 to each other. As shown in fig. 12, the wiring portion 61 is formed of a bundle of a plurality of conductor lines 610a to 610h extending in parallel to each other. The wiring section 61 includes a plurality of wiring main portions 611, and first and second branch portions 612a, 612b connecting the plurality of wiring main portions 611 to each other.

As shown in fig. 9, the connection portion 62 has a convex protrusion 621 protruding in a direction away from the hot melt layer 30A, and an exposed surface 622 of the protrusion 621 is exposed from the overcoat 70. The connection portion 62 can be used as a connection terminal to be connected to the electronic component 200 (see fig. 8), and conduction with the electronic component 200 is secured in the exposed surface 622.

As shown in fig. 12, the connection part 62 includes a plurality of connection terminals 620a₁～620h₁、620a₂～620h₂A plurality of conductor lines 610a to 610h are connected to these wires, respectively. Although not particularly shown in fig. 12, the connection terminal 620a is connected to₁～620h₁、620a₂～620h₂Electronic components 200 (see fig. 8) such as various sensors, connectors, ICs, L ED, and capacitors are provided.

In the present embodiment, the "connection terminal" is exemplified as the "connection portion 62", but the present invention is not limited thereto. As the connection portion 62, for example, a connector terminal for connecting to a connector of the electronic component 200, a pressure-sensitive sensor, or the like may be directly formed.

In the conductor portion 60 as described above, the conductor lines 610a to 610h and the connection terminal 620a₁～620h₁、620a₂～620h₂Are interconnected in the following manner. First, the conductor lines 610a to 610h are connected from the connection terminal 620a₁～620h₁Respectively, extend in the-X direction, and thereafter branch off in three directions at the first branch portions 612 a.

The conductor lines 610a and 610b are bent in the-Y direction at the first branch portion 612a, then extended in the-Y direction, and finally connected to the connection terminal 620a₂、620b₂. The conductor lines 610c and 610d extend in the-X direction without changing the extending direction, and are then connected to the connection terminals 620c₂，620d₂。

On the other hand, the conductor lines 610e to 610h are bent in the + Y direction at the first branch portion 612a, then extend to the second branch portion 612b, and are branched in two directions at the second branch portion 612 b. The conductive lines 610e, 610f are bent in the-X direction at the second branch portion 612b, then extended in the-X direction, and finally connected to the connection terminal 620e₂、620f₂. The conductor lines 610g and 610h extend in the + Y direction without changing the extending direction, and are then connected to the connection terminal 620g₂、620h₂. As a result, in eachConnection terminals 620a are connected to both ends of the conductor lines 610a to 610h₁～610h₁、620a₂～610h₂。

In the present embodiment, the wiring portion 61 has a branched planar shape, but is not limited thereto. The planar shape of the wiring portion 61 may not be branched. In addition, the wiring main body portion 611 may be a curved line. In addition, the wiring portion 61 may be constituted by one conductor line.

The conductor part 60 is configured by dispersing conductive particles in a binder, and has elasticity, as in the first embodiment.

The overcoat layer 70 is provided on the conductor portion 60 and the undercoat layer 50, and covers at least a part of the conductor portion 60, thereby protecting the conductor portion 60. Specifically, the upper surface of the wiring portion 61 and the side surface of the protruding portion 621 are covered with the overcoat layer 70. The overcoat layer 70 has a hole 701 penetrating from one main surface to the other main surface, and a protrusion 621 is formed inside the hole 701.

Like fabric 20, overcoat 70 preferably has stretch properties. As a material constituting the overcoat layer 70, the same material as that of the first embodiment can be used.

The above-described stretchable wiring board 10B of the present embodiment achieves the following effects.

The stretchable wiring board is easily bent due to its low rigidity. If the overall length of the stretchable wiring board is increased, the wiring portion becomes longer, and the region where the wiring portion is formed is likely to be bent or twisted. In contrast, in the stretchable wiring board 10B of the present embodiment, the first reinforcing member 40A, which is harder than the thermal fusion layer 30A, is disposed at a position overlapping the wiring portion 61 in a plan view, and therefore the rigidity of the portion where the first reinforcing member 40A is disposed is improved.

As a result, in the region where the wiring portion 61 of the stretchable wiring board 10B is formed, the stretchable wiring board 10B is not easily bent, and the stretchable wiring board 10B can be operated with the portion where the first reinforcing member 40A is arranged as a fulcrum, so that the operability of the stretchable wiring board 10B is improved.

Next, a method for manufacturing the stretchable wiring board 10B according to the present embodiment will be described with reference to fig. 13 and 14 (a) to 14 (h). Fig. 13 is a process diagram for explaining a method of manufacturing the stretchable wiring board 10B according to the present embodiment. Fig. 14 (a) to 14 (h) show the respective steps (step S1 to step S8) of fig. 13.

First, in step S1 in fig. 13, as shown in fig. 14 (a), a release film 80 is prepared. The release film 80 is a resin film subjected to a release treatment, and although not particularly limited, for example, a release-treated PET film can be used as the release film 80.

Next, in step S2 in fig. 13, as shown in fig. 14 (b), the overcoat layer 70 of a predetermined pattern is formed on one main surface of the release film 80. Here, the hole 701 in which the overcoat layer 70 is not formed is also formed in the release film 80 at the same time. The overcoat layer 70 is formed by applying a material constituting the overcoat layer 70 on the release film 80 and curing the material. As the coating method, various coating methods such as a screen printing method, a spray coating method, a bar coating method, a dip coating method, an ink jet method, and the like can be employed. As a curing method, irradiation with energy rays such as ultraviolet rays or infrared laser beams, heating, cooling, drying, and the like can be used.

Next, in step S3 of fig. 13, the conductor part 60 is formed as shown in fig. 14 (c). At this time, the connection part 62 is formed inside the hole 701, and the wiring part 61 is formed on the overcoat layer 70. The conductor portion 60 is formed by applying a conductive paste to the inside of the hole 701 and the overcoat layer 70 and curing the paste. As a specific example of the conductive paste forming the conductor part 60, a conductive paste in which conductive particles, a binder, water or a solvent, and various additives are mixed can be exemplified. Examples of the solvent contained in the conductive paste include ethylene glycol butyl ether acetate, carbitol acetate, butyl carbitol acetate, dipropylene glycol monobutyl ether, diethylene glycol monoethyl ether, cyclohexanone, isophorone, and terpineol. The coating method and the curing method can be the same as those used for forming the overcoat layer 70.

Next, in step S4 of fig. 13, as shown in fig. 14 (d), the undercoat layer 50 is formed on the conductor portion 60. The undercoat layer 50 is formed by applying the resin material described above to the conductor portion 60 and curing it. The coating method and the curing method can be the same as those used for forming the overcoat layer 70.

Next, in step S5 of fig. 13, as shown in fig. 14 (e), the first reinforcing member 40A and the second reinforcing member 40B are disposed on the base coat layer 50. The first reinforcing member 40A is disposed so as to overlap the connection portion 62 when viewed from the stacking direction of the layers. On the other hand, the second reinforcing member 40B is disposed so as to overlap the wiring portion 61 as viewed from the stacking direction of the respective layers. Although not particularly limited, specifically, the first and second reinforcing members 40A and 40B are formed by using the adhesive tape described above and bonding the adhesive layer of the adhesive tape to the primer layer 50.

Next, in step S6 of fig. 13, as shown in fig. 14 (f), a hot melt layer 30A is formed on the first and second reinforcing members 40A, 40B and the undercoat layer 50. The hot-melt layer 30A can be formed by disposing the thermoplastic hot-melt adhesive on the first and second reinforcing members 40A and 40B and the primer layer 50. In this case, the hot melt adhesive may be heated to be molded into an arbitrary shape. As the adhesive, a sheet-like hot-melt adhesive may be used, and the sheet-like hot-melt adhesive may be bonded to the first and second reinforcing members 40A and 40B and the primer layer 50 by using a heat laminating device or the like.

Next, in step S7 of fig. 13, as shown in fig. 14 (g), the hot-melt layer 30A is attached to the web 20. Although not particularly limited, specifically, the hot-melt layer 30A is attached to the fabric 20 in a state softened by heating. In particular, in the stretchable wiring board 10B of the present embodiment, the second reinforcing member 40B imparts rigidity to the region where the wiring portion 61 is formed, and therefore the workability of the stretchable wiring board 10B in the bonding work is improved.

Next, in step S8 in fig. 13, as shown in fig. 14 (h), release film 80 is peeled off from stretchable wiring board 10B. The timing of peeling the release film 80 is not limited to the timing after the pasting of the web 20. For example, the release film 80 may be peeled off after the hot melt layer 30A is formed (after step S6 of fig. 13) and before the web 20 is pasted (before step S7 of fig. 13).

< third embodiment >

Fig. 15 is a sectional view of a stretchable wiring board 10C according to a third embodiment of the present invention. The present embodiment differs from the second embodiment in that the stretchable wiring board 10C includes the joint tape 90, and otherwise has the same configuration as the second embodiment. Only the joint tape 90, which is a difference from the second embodiment in the third embodiment, will be described below, and the same reference numerals are given to parts having the same configuration as that of the second embodiment, and the description thereof will be omitted. The "seam tape 90" in the present embodiment corresponds to the "second stretchable base material" in the present invention.

The stretchable wiring board 10C is different from the stretchable wiring board 10B according to the second embodiment in that the joint tape 90 is attached to the overcoat 70. The joint tape 90 is attached to a position corresponding to the wiring portion 61.

The joint tape 90 has elasticity, and the joint tape 90 is not particularly limited, but an article having a hot melt on the main surface of a film made of a polyurethane elastomer can be used. The seam tape 90 is softer than the second reinforcing member 40B (in other words, the second reinforcing member 40B is harder than the seam tape 90), and the young's modulus E of the seam tape 90_sYoung's modulus E of the second reinforcing member_RBSmall (E)_s＜E_RB). In addition, elongation at break B of the seam tape 90_sElongation at break B of specific heat fused layer 30A_hLarge (B)_s＞B_h)。

As in the second embodiment, the flexible wiring board 10C of the third embodiment can also improve the operability of the flexible wiring board 10C. In particular, the joint tape 90 further improves the rigidity of the portion of the stretchable wiring board 10C where the wiring portion 61 is formed, and thus further improves the workability.

Further, the "second stretch substrate" is not limited to the seam tape 90. As the "second stretchable base material", various resin materials can be used, and particularly, it is preferable to have water repellency. In the third embodiment, a "joint tape" is exemplified as the resin material having water repellency.

The method for manufacturing the stretchable wiring board 10C of the present embodiment is basically the same as the method for manufacturing the stretchable wiring board 10B of the second embodiment, but differs from the second embodiment in that a step of attaching a seam tape 90 is provided after step S8 in fig. 13. In this step, the hot melt of the joint tape 90 may be adhered to the overcoat layer 70 by a heat lamination device or the like. Thereby, the stretchable wiring board 10C is manufactured.

< fourth embodiment >

Fig. 16 is a sectional view of a stretchable wiring board 10D according to a fourth embodiment of the present invention. In the present embodiment, the first stretchable base material of the stretchable wiring board 10D is different from the second embodiment in that the fabric 20 is not attached thereto, not the hot-melt layer 30A but the elastic body layer 30B, and is otherwise the same as the second embodiment. Only the differences between the fourth embodiment and the second embodiment will be described below, and the same reference numerals are given to the same components as those of the second embodiment, and the description thereof will be omitted. The "elastomer layer 30B" in the present embodiment corresponds to the "first stretchable base material" in the present invention.

The elastomer layer 30B is formed in the lowermost part of the stretchable wiring board 10D, and has substantially the same planar shape as the undercoat layer 50, the conductor section 60, and the overcoat layer 70. In the present embodiment, the first and second reinforcing members 40A and 40B are embedded in the elastomer layer 30B, and the primer layer 50 is formed on the elastomer layer 30B. The elastic layer 30B is not bonded to the fabric 20 of the first embodiment.

As a material constituting the elastic body layer 30B, for example, natural rubber, styrene-butadiene rubber, chloroprene rubber, butyl rubber, nitrile rubber, ethylene-propylene rubber, acrylate rubber, urethane rubber, silicone rubber, fluorine rubber, or the like can be used. In addition, other elastomeric materials may also be used.

Young's modulus E of elastomer layer 30B_EPreferably 0.1 to 35MPa, and a maximum elongation L E as the maximum elongation of the elastomer layer 30B_EPreferably 5 to 50%. Further, the elongation at break B of the elastomer layer 30B is_EPreferably 50% or more. The thickness T of the elastomer layer 30B is_EPreferably 20 to 300 μm.

As in the second embodiment, the flexible wiring board 10D of the fourth embodiment can also improve the operability of the flexible wiring board 10D.

The stretchable wiring board 10D according to the fourth embodiment can be produced by printing an undercoat layer, a printed conductor part, and a printed overcoat layer on an elastomer base material.

< fifth embodiment >

Fig. 17 is a sectional view of a stretchable wiring board 10E according to a fifth embodiment of the present invention. The present embodiment is different from the fourth embodiment in that the first and second reinforcing members 40A, 40B are formed on the lowermost surface of the stretchable wiring board 10E, and is similar to the fourth embodiment except for the above. Only the differences between the fifth embodiment and the fourth embodiment will be described below, and the same reference numerals are given to the same components as those of the third embodiment, and the description thereof will be omitted.

In the stretchable wiring board 10E according to the fifth embodiment, the first and second reinforcing members 40A and 40B are attached to the lower surface of the elastomer layer 30B. That is, the first and second reinforcing members 40A, 40B are not embedded in the elastomer layer 30B, the first and second reinforcing members 40A, 40B are disposed away from the undercoat layer 50, and the elastomer layer 30B is interposed between the undercoat layer 50 and the first and second reinforcing members 40A, 40B.

As in the second embodiment, the flexible wiring board 10E of the fifth embodiment can also improve the operability of the flexible wiring board 10E.

The stretchable wiring board 10E according to the fifth embodiment can be manufactured by a manufacturing method basically similar to the manufacturing method of the stretchable wiring board 10D according to the fourth embodiment, except that the first and second reinforcing members 40A and 40B are attached to the elastic body layer 30B after the elastic body layer 30B is formed.

The embodiments described above are described for easy understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design changes and equivalents that also fall within the technical scope of the present invention.

For example, the method for manufacturing the stretchable wiring board 10A is not limited to the first embodiment described above, and the order of performing the second to seventh steps is not limited to the order in the above-described embodiment. For example, the third step may be performed before the second step. That is, the connection portion 62 may be formed on the release film 80 before the overcoat 70 is formed, and thereafter, the overcoat 70 may be formed and then the wiring portion 61 may be formed.

The first and second reinforcing members 40A, 40B may be adhered to the outer coating 70. For example, if sufficient water repellency can be ensured, the primer layer 50 may be omitted. That is, in the above-described embodiment, the conductor part 60 is indirectly provided on the hot-melt layer 30A or the elastomer layer 30B via the primer layer 50, but the conductor part 60 may be directly provided on the first stretchable base material, and "provided on the first stretchable base material" in the present embodiment means "provided indirectly or directly on the first stretchable base material".

The method for manufacturing the stretchable wiring board 10B is not limited to the above-described embodiment, and the sequence of performing step 2 to step 8 is not limited to the sequence in the second embodiment (see fig. 12). For example, the connection portion 62 may be formed on the release film 80 before the overcoat 70 is formed, and then the overcoat 70 may be formed and then the wiring portion 61 may be formed.

In addition, a part of the connection portion 62 may be formed on the release film 80 before the overcoat 70 is formed, and then the overcoat 70 may be formed, and then the remaining part of the connection portion 62 and the wiring portion 61 may be formed at the same time. For example, such a manufacturing method can be used when a part of the connection portion 62 contains conductive particles of a different kind from the wiring portion 61, and the remaining part of the connection portion 62 contains conductive particles of the same kind as the wiring portion 61. More specifically, such a manufacturing method can be used when a part of the connection portion 62 contains carbon as conductive particles and the rest of the connection portion 62 and the wiring portion 61 contain silver as conductive particles.

Description of the reference numerals

10A, 10B, 10C, 10D, 10E-stretch wiring boards; 20-a fabric; 21-a first fiber bundle; 22-a second fiber bundle; 23-gap; 201-one major face; 202-the other major face; 30A-hot melt layer; 30B-an elastomer; 40A-a first reinforcing component; 40B, 40B₁、40B₂-a first reinforcement part; 50-a base coat; 60-a conductor portion; 61-a wiring section; 610 a-610 h-conductor lines; 611-a wiring body portion; 612 a-a first branch portion; 612 b-a second branch portion; 62-a connecting part; 601-lower surface; 602-a lateral side; 621-a projection; 622-exposed side; 70-an outer coating; 701-holes; 702-a surface; 80-a release film; 90-seam tape; 200-an electronic component.