JP2022162359A - Wiring board and method for manufacturing wiring board - Google Patents

Abstract

To provide a wiring board and a method for manufacturing the wiring board for suppressing occurrence of damage to wiring even when a base material is greatly locally deformed.SOLUTION: A wiring board with an electronic component includes, in plan view, at least one first rigid member 30 overlapping a base material and an electronic component and having higher rigidity than the base material, and a conductive layer including wiring 51. The first rigid member has an outer edge that includes at least two first corners 32 and a first side 31 that are chamfered. The base material includes a first overlapping region 23 overlapping the first rigid member and a first peripheral region 24 contacting the first overlapping region and not overlapping the first rigid member. The first peripheral region includes a first stable region 241 extending from the central portion of the first side toward the side away from the center of the first rigid member in plan view. The first stable region has a dimension W1 of the following formula in the direction in which the first side extends. W1=-1.1148×R1+0.532×K1. R1 is the first corner chamfer dimension, and K1 is the dimension of the two first corners of the first side and the first side.SELECTED DRAWING: Figure 4

Description

An embodiment of the present disclosure relates to a wiring board and a manufacturing method thereof.

In recent years, research has been conducted on electronic devices having deformability such as stretchability. For example, Patent Literature 1 discloses a flexible wiring board that includes a base material and wiring provided on the base material. Patent Document 1 employs a manufacturing method in which a circuit is formed on a pre-stretched base material, and the base material is relaxed after the circuit is formed. The wiring board described in Patent Document 1 includes a reinforcing member that overlaps an electronic component mounted on the wiring board.

WO2019/074115

When tension is applied to the base material, deformation of the area of the base material that overlaps the reinforcing member in plan view is suppressed by the reinforcing member. In this case, the region of the base material located around the reinforcing member may be locally significantly deformed. If the base material is deformed locally to a large extent, it is conceivable that the wiring may be broken or otherwise damaged.

An object of the embodiments of the present disclosure is to provide a wiring board and a wiring board manufacturing method that can effectively solve such problems.

One embodiment of the present disclosure provides:
A wiring board on which electronic components are mounted,
a stretchable base material including a first surface and a second surface located on the opposite side of the first surface;
at least one first rigid member overlapping the base material and the electronic component in plan view and having higher rigidity than the base material;
a conductive layer including wiring located on the first surface side of the base material,
The first rigid member has, in plan view, at least two first corners that are chamfered on a side away from the center of the first rigid member, and a first side that extends between the two first corners. with an outer rim containing
The base material includes a first overlapping region that overlaps the first rigid member in plan view, and a first surrounding region that is in contact with the first overlapping region and does not overlap the first rigid member in plan view,
The first peripheral region includes a first stable region that spreads from the center of the first side toward the side away from the center of the first rigid member in a plan view,
The first stable region has a dimension W1 represented by the following formula in the direction in which the first side extends,
W1 = -1.1148 x R1 + 0.532 x K1
R1 is the chamfer dimension of the first corner, K1 is the dimensions of the two first corners and the first side in the direction in which the first side extends,
The wiring is a wiring substrate extending through the first stability region to the first overlap region.

In the wiring board according to an embodiment of the present disclosure, R1/K1 may be 0.020 or more and 0.30 or less.

In the wiring board according to one embodiment of the present disclosure, the elastic modulus of the first rigid member may be 10 times or more the elastic modulus of the base material.

In the wiring board according to one embodiment of the present disclosure, the first rigid member may be positioned on the second surface side of the base material.

In the wiring board according to one embodiment of the present disclosure, the first rigid member may be embedded in the base material.

A wiring board according to an embodiment of the present disclosure includes a first insulating layer that overlaps the first rigid member and partially covers the conductive layer in plan view, and a first insulating layer that overlaps the conductive layer in plan view and includes the first insulating layer. and a first hole penetrating the.

In the wiring board according to an embodiment of the present disclosure, the conductive layer may include a pad surrounding the first hole in plan view and connected to the wiring.

A wiring board according to an embodiment of the present disclosure includes at least one second rigid member that partially overlaps the base material in a plan view, and a conductive member provided on the second rigid member and electrically connected to the wiring. a body, the electronic component electrically connected to the wiring via the conductor, the electronic component located on the first surface side of the base material, having a rigidity lower than that of the second rigid member, and the A protective layer covering the second rigid member and the electronic component may be provided. The second rigid member has, in plan view, at least two second corners that are chamfered on the side away from the center of the second rigid member, and a second side that extends between the two second corners. It may have an outer edge that includes. The protective layer includes a second overlapping region that overlaps the second rigid member in plan view, and a second surrounding region that is in contact with the second overlapping region and does not overlap the second rigid member in plan view. good too. The second peripheral region may include a second stable region extending from the central portion of the second side toward a side away from the center of the second rigid member in plan view. The second stable region may have a dimension W2 expressed by the following formula in the direction in which the second side extends.
W2 = -1.1148 x R2 + 0.532 x K2
R2 is the chamfer dimension of the second corner, and K2 is the dimension of the two second corners and the second side in the extending direction of the second side. The wiring may extend through the second stability region to the second overlap region.

One embodiment of the present disclosure provides:
a stretchable base material including a first surface and a second surface located on the opposite side of the first surface;
a conductive layer including wiring located on the first surface side of the base;
at least one second rigid member that partially overlaps the base material in plan view;
a conductor provided on the second rigid member and electrically connected to the wiring;
an electronic component that overlaps the second rigid member in plan view and is electrically connected to the wiring via the conductor;
a protective layer located on the first surface side of the base material, having a lower rigidity than the second rigid member, and covering the second rigid member and the electronic component;
The second rigid member has, in plan view, at least two second corners that are chamfered on the side away from the center of the second rigid member, and a second side that extends between the two second corners. with an outer rim containing
The protective layer includes a second overlapping region that overlaps the second rigid member in plan view, and a second surrounding region that is in contact with the second overlapping region and does not overlap the second rigid member in plan view,
The second peripheral region includes a second stable region that spreads from the central portion of the second side toward the side away from the center of the second rigid member in a plan view,
The second stable region has a dimension W2 represented by the following formula in the direction in which the second side extends,
W2 = -1.1148 x R2 + 0.532 x K2
R2 is the chamfer radius of the second corner, K2 is the dimension of the two second corners and the second side in the direction in which the second side extends,
The wiring is a wiring substrate extending through the second stability region to the second overlap region.

In the wiring board according to an embodiment of the present disclosure, R2/K2 may be 0.020 or more and 0.30 or less.

In the wiring board according to one embodiment of the present disclosure, the elastic modulus of the second rigid member may be ten times or more the elastic modulus of the protective layer.

A wiring board according to an embodiment of the present disclosure includes a first insulating layer that overlaps the second rigid member in plan view and partially covers the conductive layer, and a first insulating layer that overlaps the conductive layer in plan view and includes the first insulating layer. and solder located in the first hole and connected to the conductive layer and the conductor.

In the wiring board according to an embodiment of the present disclosure, the conductive layer may include a pad surrounding the first hole in plan view and connected to the wiring.

In the wiring board according to one embodiment of the present disclosure, the base material may contain thermoplastic elastomer, silicone rubber, urethane gel, or silicone gel.

A wiring board according to an embodiment of the present disclosure may include a support substrate that supports the wiring.

In the wiring board according to an embodiment of the present disclosure, the modulus of elasticity of the support substrate may be ten times or more the modulus of elasticity of the base material.

In the wiring board according to one embodiment of the present disclosure, the support substrate may contain polyethylene naphthalate, polyimide, polycarbonate, acrylic resin, or polyethylene terephthalate.

A wiring board according to an embodiment of the present disclosure may include a second insulating layer located on the first surface side of the base material and at least partially overlapping the wiring in plan view.

In the wiring board according to one embodiment of the present disclosure, the control layer may have a larger elastic modulus than the base material.

In the wiring board according to one embodiment of the present disclosure, the wiring may include a plurality of ridges arranged in the length direction of the wiring.

An embodiment of the present disclosure is a method for manufacturing a wiring board on which electronic components are mounted,
A stretchable substrate including a first surface and a second surface located on the opposite side of the first surface, overlapping the substrate and the electronic component in plan view, and having higher rigidity than the substrate a stretching step of applying tension to the substrate of a laminate comprising at least one first rigid member to elongate the substrate;
a wiring forming step of providing wiring on the first surface side of the base material stretched by the stretching step;
a shrinking step that removes tension from the substrate;
The first rigid member has, in plan view, at least two first corners that are chamfered on a side away from the center of the first rigid member, and a first side that extends between the two first corners. with an outer rim containing
The base material includes a first overlapping region that overlaps the first rigid member in plan view, and a first surrounding region that is in contact with the first overlapping region and does not overlap the first rigid member in plan view,
The first peripheral region includes a first stable region that spreads from the center of the first side toward the side away from the center of the first rigid member in a plan view,
The first stable region has a dimension W1 represented by the following formula in the direction in which the first side extends,
W1 = -1.1148 x R1 + 0.532 x K1
R1 is the chamfer dimension of the first corner, K1 is the dimensions of the two first corners and the first side in the direction in which the first side extends,
In the method of manufacturing a wiring board, the wiring extends through the first stable region to reach the first overlapping region.

One embodiment of the present disclosure provides:
an elongation step of applying tension to a stretchable substrate comprising a first surface and a second surface located opposite to the first surface to elongate the substrate;
a wiring forming step of providing wiring on the first surface side of the base material stretched by the stretching step;
a shrinking step that removes tension from the substrate;
At least one second rigid member, a conductor provided on the second rigid member and electrically connected to the wiring, and the second rigid member in plan view on the first surface side of the base material an electronic component that overlaps with the conductor and is electrically connected to the wiring via the conductor; a protective layer that has lower rigidity than the second rigid member and covers the second rigid member and the electronic component; is provided,
The second rigid member has, in plan view, at least two second corners that are chamfered on the side away from the center of the second rigid member, and a second side that extends between the two second corners. with an outer rim containing
The protective layer includes a second overlapping region that overlaps the second rigid member in plan view, and a second surrounding region that is in contact with the second overlapping region and does not overlap the second rigid member in plan view,
The second peripheral region includes a second stable region that spreads from the central portion of the second side toward the side away from the center of the second rigid member in a plan view,
The second stable region has a dimension W2 represented by the following formula in the direction in which the second side extends,
W2 = -1.1148 x R2 + 0.532 x K2
R2 is the chamfer dimension of the second corner, K2 is the dimension of the two second corners and the second side in the direction in which the second side extends,
In the method of manufacturing a wiring board, the wiring extends through the second stable region to reach the second overlapping region.

According to the embodiments of the present disclosure, it is possible to suppress the occurrence of damage such as breakage in wiring.

1 is a plan view showing a wiring board according to one embodiment; FIG. FIG. 2 is a cross-sectional view of the wiring substrate of FIG. 1 taken along line AA; FIG. 4 is an enlarged plan view showing wiring positioned around the first rigid member; FIG. 4 is a plan view showing a state in which the first insulating layer is removed from FIG. 3; The top view which expands and shows the 1st corner of a 1st rigid member. FIG. 4 is a cross-sectional view showing an example of ridges formed on a wiring board; FIG. 10 is a cross-sectional view showing another example of ridges formed on the wiring board; FIG. 4 is a plan view showing an example of ridges formed on a wiring board; FIG. 10 is a cross-sectional view showing another example of ridges formed on the wiring board; FIG. 10 is a cross-sectional view showing another example of ridges formed on the wiring board; It is a figure for demonstrating the manufacturing method of a wiring board. It is a figure for demonstrating the manufacturing method of a wiring board. It is a figure for demonstrating the manufacturing method of a wiring board. It is a figure for demonstrating the method of mounting an electronic component in a wiring board. It is a figure for demonstrating the method of mounting an electronic component in a wiring board. FIG. 4 is a cross-sectional view showing an enlarged wiring board in an extended state; It is a top view which shows the wiring board which concerns on a 1st modification. FIG. 15 is a cross-sectional view of the wiring substrate of FIG. 14 taken along line BB; FIG. 11 is a cross-sectional view showing a wiring board according to a second modified example; FIG. 11 is a cross-sectional view showing a wiring board according to a second modified example; FIG. 11 is a cross-sectional view showing a wiring board according to a third modified example; FIG. 19 is a cross-sectional view showing an example of ridges formed on the wiring substrate of FIG. 18; It is a figure for demonstrating the manufacturing method of a wiring board. It is a figure for demonstrating the manufacturing method of a wiring board. It is a figure for demonstrating the manufacturing method of a wiring board. It is a figure for demonstrating the manufacturing method of a wiring board. FIG. 11 is a cross-sectional view showing a wiring board according to a fourth modified example; FIG. 11 is a cross-sectional view showing a wiring board according to a fifth modified example; FIG. 11 is a cross-sectional view showing a wiring board according to a sixth modification; FIG. 14 is a cross-sectional view showing a wiring board according to a seventh modification; FIG. 11 is a plan view showing a wiring board according to a seventh modification; FIG. 20 is a cross-sectional view showing a wiring board according to an eighth modification; FIG. 20 is a cross-sectional view showing a wiring board according to an eighth modification; FIG. 21 is a plan view showing a first rigid member according to a ninth modification; FIG. 21 is a plan view showing a first rigid member according to a tenth modified example; FIG. 21 is a plan view showing a first rigid member according to an eleventh modification; FIG. 3 is a plan view showing a laminate in an example; FIG. 3 is a cross-sectional view showing a laminate in an example; FIG. 4 is a plan view showing the result of calculating the volumetric strain generated in the base material by simulation. 4 is a graph showing the result of calculating the volumetric strain generated in the base material by simulation. FIG. 10 is a table showing the results of calculation by simulation of volumetric strain occurring in a base material; FIG. FIG. 35 is a table showing the results of normalizing the volume strain of FIG. 34; FIG. 10 is a graph showing the relationship between normalized volumetric strain and normalized chamfer dimension;

(First embodiment)
Hereinafter, the configuration of the wiring board and the manufacturing method thereof according to the first embodiment of the present disclosure will be described in detail with reference to the drawings. The embodiments described below are examples of embodiments of the present disclosure. Interpretation of this disclosure is not limited to these embodiments. As used herein, the terms "substrate", "substrate", "sheet", "film" and the like are not to be distinguished from each other based solely on their designation. For example, the concept of "substrate" also includes such members as may be referred to as substrates, sheets, and films. Interpretations of terms such as "parallel" and "perpendicular" and values of lengths and angles used herein to specify shapes and geometric conditions as well as degrees thereof are not strictly limited. However, it includes the extent to which similar functions can be expected.

In the drawings referred to in this embodiment, the same reference numerals or similar reference numerals are given to the same parts or parts having similar functions. Repeated descriptions of parts to which the same or similar reference numerals are attached may be omitted. The dimensional ratios in the drawings may differ from the actual ratios for convenience of explanation. Some configurations may be omitted from the drawings.

In this specification, when multiple upper limit candidates and multiple lower limit candidates are given for a parameter, the numerical range of the parameter is any one upper limit candidate and any one lower limit value. may be configured by combining the candidates of For example, "Parameter B is, for example, A1 or more, may be A2 or more, or may be A3 or more. Parameter B may be, for example, A4 or less, may be A5 or less, or A6 or less. There may be.” In this case, the numerical range of the parameter B may be A1 or more and A4 or less, A1 or more and A5 or less, A1 or more and A6 or less, or A2 or more and A4 or less, It may be A2 or more and A5 or less, A2 or more and A6 or less, A3 or more and A4 or less, A3 or more and A5 or less, or A3 or more and A6 or less.

(wiring board)
FIG. 1 is a plan view showing a wiring substrate 10 according to this embodiment. FIG. 2 is a cross-sectional view of the wiring board 10 of FIG. 1 along line AA. The wiring board 10 includes a base material 20 , a first rigid member 30 and a conductive layer 50 . The wiring board 10 may include a first insulating layer 70 . An electronic component 55 is mounted on the wiring board 10 . The concept of "wiring board" includes both the wiring board 10 before the electronic component 55 is mounted and the wiring board 10 after the electronic component 55 is mounted.

〔Base material〕
The base material 20 is a member configured to be stretchable in at least one direction. The substrate 20 includes a first side 21 and a second side 22 opposite the first side 21 . In the example shown in FIG. 1, the base material 20 has a pair of sides extending in a first direction D1 and a second direction orthogonal to the first direction D1 when viewed along the normal direction of the surface of the base material 20. It has a quadrangular shape including a pair of sides extending to D2. In the following description, viewing the wiring board 10 along the normal direction of the surface of the base material 20 may also be expressed as "plan view". In addition, when the wiring board 10 is viewed along the normal direction of the surface of the base material 20, the overlapping of two components of the wiring board 10 may be expressed as "overlapping". The base material 20 has stretchability at least in the first direction D1. The base material 20 may also have elasticity in directions other than the first direction D1. For example, the base material 20 may have stretchability also in the second direction D2.

The thickness T1 of the base material 20 is, for example, 10 μm, may be 20 μm or more, or may be 30 μm or more. The thickness T1 of the base material 20 is, for example, 10 mm or less, may be 3 mm or less, or may be 1 mm or less. By setting the thickness T1 of the base material 20 to 10 μm or more, the durability of the base material 20 can be ensured. By setting the thickness T1 of the base material 20 to 10 mm or less, it is possible to ensure comfort when the wiring board 10 is worn. If the thickness T1 of the base material 20 is too small, the stretchability of the base material 20 may be impaired.

The stretchability of the base material 20 refers to the property that the base material 20 can be stretched from its normal non-stretched state, and then the base material 20 can be restored when released from the stretched state. In the following description, the property of being able to restore when released from the stretched state is also referred to as resilience. The non-stretched state is the state of substrate 20 when no tensile stress is applied. The extent to which the base material 20 can be stretched from the non-stretched state without being destroyed is, for example, 1% or more, may be 20% or more, or may be 75% or more. By using the base material 20 having such characteristics, the wiring board 10 as a whole can have elasticity. Furthermore, the wiring board 10 can be used in products and applications that require high elasticity, such as those attached to a part of the body such as a human arm. Generally, it is said that a product to be applied to a person's armpit should have a stretchability of 72% in the vertical direction and 27% in the horizontal direction. In addition, it is said that products that are attached to the knees, elbows, buttocks, ankles, and armpits of a person must have a stretchability of 26% or more and 42% or less in the vertical direction. It is also said that less than 20% stretchability is required for products that are attached to other parts of the human body.

It is preferable that the difference between the shape of the substrate 20 in the non-stretched state and the shape of the substrate 20 when it returns to the non-stretched state after being stretched from the non-stretched state is small. This difference is also referred to as shape change in the following description. The change in shape of the substrate 20 is, for example, 20% or less, may be 10% or less, or may be 5% or less in terms of area ratio. By using the base material 20 with a small change in shape, formation of peaks and valleys, which will be described later, is facilitated.

A parameter representing the stretchability of the base material 20 is, for example, an elastic modulus. The elastic modulus of the base material 20 is, for example, 10 MPa or less, and may be 1 MPa or less. By using the base material 20 having such an elastic modulus, the wiring board 10 as a whole can have stretchability. The elastic modulus of the base material 20 is, for example, 1 kPa or more, and may be 10 kPa or more.

As a method for calculating the elastic modulus of the base material 20, a method of performing a tensile test in accordance with JIS K6251 using a sample of the base material 20 can be adopted. Alternatively, a method of measuring the elastic modulus of a sample of the base material 20 by a nanoindentation method in compliance with ISO14577 may be adopted. A nanoindenter can be used as a measuring instrument used in the nanoindentation method. As a method of preparing a sample of the base material 20, a method of taking out a part of the base material 20 from the wiring board 10 as a sample and a method of taking out a part of the base material 20 before forming the wiring board 10 as a sample are considered. be done. In addition, as a method of calculating the elastic modulus of the base material 20, a method of analyzing the materials forming the base material 20 and calculating the elastic modulus of the base material 20 based on an existing material database can be adopted. The elastic modulus in the present application is the elastic modulus in an environment of 25°C.

Another example of the parameter representing the stretchability of the base material 20 is the flexural rigidity of the base material 20 . Bending stiffness is the product of the area moment of inertia of the member under consideration and the elastic modulus of the material that constitutes the member under consideration. The unit of bending stiffness is N·m ² or Pa·m ⁴ . The geometrical moment of inertia of the base material 20 is calculated based on a cross section obtained by cutting a portion of the base material 20 overlapping the wiring 51 along a plane perpendicular to the expansion/contraction direction of the wiring board 10 .

Base material 20 may contain an elastomer as a main component. Also, the base material 20 may contain cloth such as woven fabric, knitted fabric, or non-woven fabric as a main component. In addition, the "main component" is a component that accounts for 51% by weight or more of the constituent elements of interest. As the elastomer, general thermoplastic elastomers and thermosetting elastomers can be used. Elastomers include, for example, polyurethane elastomers, styrene elastomers, nitrile elastomers, olefin elastomers, vinyl chloride elastomers, ester elastomers, amide elastomers, 1,2-BR elastomers, fluorine elastomers, silicone rubbers, and urethane rubbers. , fluororubber, polybutadiene, polyisobutylene, polystyrene butadiene, polychloroprene, and the like. Considering mechanical strength and abrasion resistance, it is preferable to use a urethane-based elastomer. Substrate 20 may comprise a silicone such as polydimethylsiloxane. Silicone has excellent heat resistance, chemical resistance, and flame resistance.

[First rigid member]
The first rigid member 30 is a member arranged so as to overlap the base material 20 in plan view. The wiring board 10 has at least one first rigid member 30 . As shown in FIGS. 1 and 2 , the wiring board 10 may have two or more first rigid members 30 . As shown in FIG. 2 , the first rigid member 30 may be positioned on the second surface 22 side of the substrate 20 .

The first rigid member 30 has higher rigidity than the base material 20 . Therefore, when a force such as tension is applied to the wiring board 10 , the area of the base material 20 that overlaps the first rigid member 30 expands or contracts more than the area of the base material 20 that does not overlap the first rigid member 30 . deformation is less likely to occur. In the following description, the area of the base material 20 that overlaps the first rigid member 30 in plan view is also referred to as a first overlap area 23, and the area of the base material 20 that does not overlap the first rigid member 30 in plan view is referred to as the first overlap area. Also referred to as peripheral region 24 .

As shown in FIGS. 1 and 2, the electronic component 55 is arranged so as to overlap the first rigid member 30 in plan view. That is, the electronic component 55 is arranged so as to overlap the first overlap region 23 in plan view. Accordingly, when a force such as tension is applied to the wiring board 10 and when the force is removed from the wiring board 10 , application of force to the electronic component 55 can be suppressed. Therefore, the electronic component 55 can be prevented from being deformed or damaged. In addition, it is possible to suppress deformation, breakage, and the like of the joint between the electronic component 55 and the wiring board 10 .

The thickness T2 of the first rigid member 30 is, for example, 10 μm, may be 20 μm or more, or may be 30 μm or more. The thickness T2 of the first rigid member 30 is, for example, 1 mm or less, may be 300 μm or less, or may be 100 μm or less.

A parameter representing the stiffness of the first rigid member 30 is, for example, an elastic modulus. The elastic modulus of the first rigid member 30 may be higher than the elastic modulus of the base material 20 . The elastic modulus of the first rigid member 30 is, for example, 10 times or more, may be 100 times or more, or may be 1000 times or more that of the base material 20 . The elastic modulus of the first rigid member 30 is, for example, 10,000 times or less, and may be 50,000 times or less, that of the base material 20 . The elastic modulus of the first rigid member 30 is, for example, 1 GPa or more, and may be 10 GPa or more.

A method for calculating the elastic modulus of the first rigid member 30 is appropriately determined according to the form of the first rigid member 30 . For example, the method for calculating the elastic modulus of the first rigid member 30 may be the same as or different from the method for calculating the elastic modulus of the base material 20 . For example, as a method of calculating the elastic modulus of the first rigid member 30, a method of performing a tensile test in accordance with ASTM D882 using a sample of the first rigid member 30 can be adopted.

The first rigid member 30 is composed of a metal layer containing a metal material, general thermoplastic elastomer, acrylic, urethane, epoxy, polyester, epoxy, vinyl ether, polyene/thiol, and silicone oligomers. , polymers, and the like. Metal materials are, for example, copper, aluminum, stainless steel, and the like. The first rigid member 30 may be a base material used in printed circuit boards. Base materials used in printed circuit boards are glass epoxy, paper phenol, and the like. Glass epoxy is glass fiber impregnated with epoxy resin. Paper phenol is paper impregnated with phenolic resin.

[Conductive layer]
The conductive layer 50 is a layer having conductivity. The conductive layer 50 is located on the first surface 21 side of the base material 20 . As shown in FIG. 2, the conductive layer 50 may be located on the first surface 21 . Conductive layer 50 includes at least wiring 51 . The wiring 51 is electrically connected to the electronic component 55 . Conductive layer 50 may include pads 52 . Pad 52 is connected to wiring 51 . For example, the pad 52 is connected to the end of the wiring 51 . The wiring 51 and the pad 52 may be integrally configured by the conductive layer 50 .

Terminals, pads, and the like of an electronic component 55 are connected to the pads 52 via solder 54 or the like. As will be described later, when a printed circuit board is provided between the wiring board 10 and the electronic component 55, the pads 52 are connected to terminals, pads, etc. of the printed circuit board via solder or the like.

FIG. 3 is an enlarged plan view showing the wiring 51 positioned around the first rigid member 30. As shown in FIG. In FIG. 3, the electronic component 55 and the solder 54 are omitted for convenience. FIG. 4 is a plan view showing a state in which the first insulating layer 70 is removed from FIG. 3 and 4 show the wiring board 10 as viewed from the first surface 21 side.

The wiring 51 is a member having conductivity and having an elongated shape in plan view. In the example shown in FIG. 1, the wiring 51 extends in the first direction D1 or the second direction D2. The length of the wiring 51 is, for example, twice or more the width of the wiring 51, may be five times or more, or may be ten times or more. The length of the wiring 51 is the dimension of the wiring 51 in the direction in which the wiring 51 extends. The width of the wiring 51 is the dimension of the wiring 51 in the direction orthogonal to the direction in which the wiring 51 extends.

The width W2 of the wiring 51 is appropriately selected according to the electrical resistance value required for the wiring 51 . The width W2 of the wiring 51 is, for example, 100 μm or more, may be 200 μm or more, may be 500 μm or more, or may be 1 mm or more. The width W2 of the wiring 51 is, for example, 20 mm or less, may be 10 mm or less, or may be 5 mm or less.

The width of the pad 52 may be larger than the width of the wiring 51 . The width of the pad 52 is the dimension of the pad 52 in the direction perpendicular to the direction in which the wiring 51 extends.

In FIGS. 3 and 4, the outline of the first rigid member 30 located on the second surface 22 side is indicated by dotted lines. The area of the base material 20 located inside the dotted line is the first overlapping area 23 described above. The wiring 51 extends from the first peripheral region 24 to the first overlapping region 23 . Pad 52 is located in first overlap region 23 .

When deformation such as expansion and contraction occurs in the base material 20 , force is applied to the conductive layer 50 such as the wiring 51 . For example, the wiring 51 may be provided on the substrate 20 in a state of being stretched by a first stretch amount under tension. In this case, when the tension is removed from the substrate 20 and the substrate 20 contracts, the wiring 51 deforms into a bellows shape. As a result, the wiring 51 has a plurality of ridges aligned in the length direction.

The conductive layer 50 that constitutes the wiring 51 may contain a material that can follow the expansion and contraction of the base material 20 by using elimination and formation of peaks. The material of the conductive layer 50 itself may or may not have elasticity.
Examples of materials for the non-stretchable conductive layer 50 include metals such as gold, silver, copper, aluminum, platinum, and chromium, and alloys containing these metals.
Examples of materials for the stretchable conductive layer 50 include a conductive composition having a base material and a plurality of conductive particles dispersed within the base material. By using a deformable material such as resin as the base material, the wiring 51 can also be deformed according to the expansion and contraction of the base material 20 . Moreover, the conductivity of the wiring 51 can be maintained by setting the distribution and shape of the conductive particles so that the contact between the plurality of conductive particles is maintained even when deformation occurs.

Common thermoplastic elastomers and thermosetting elastomers can be used as the base material. Examples of the base material include styrene elastomer, acrylic elastomer, olefin elastomer, urethane elastomer, silicone rubber, urethane rubber, fluororubber, nitrile rubber, polybutadiene, and polychloroprene. Resins and rubbers containing urethane-based or silicone-based structures are preferable as the base material because they have stretchability and durability. Materials for the conductive particles include, for example, silver, copper, gold, nickel, palladium, platinum, and carbon. In particular, silver particles are preferably used.

A method for forming the conductive layer 50 including the wiring 51 is appropriately selected according to the material and the like. For example, a metal film is formed on the base material 20 or a support substrate 40 to be described later by a vapor deposition method, a sputtering method, lamination of metal foil, or the like. After that, the metal film is patterned by photolithography. Thereby, the wiring 51 is formed. When a metal foil is laminated on the base material 20 or a support substrate 40 described later, an adhesive layer or the like may be interposed between the base material 20 or the support substrate 40 and the metal foil. Further, when the material of the wiring 51 itself has stretchability, for example, the conductive composition containing the above-described conductive particles and elastomer is patterned on the base material 20 or the support substrate 40 by a general printing method. You may print. Among these methods, the printing method can be preferably used. Since the printing method has high material efficiency, the wiring 51 can be manufactured at low cost.

The thickness T3 of the conductive layer 50 is appropriately selected according to the material of the conductive layer 50 and the like so as to withstand expansion and contraction of the base material 20 .
When the material of the conductive layer 50 does not have elasticity, the thickness T3 of the conductive layer 50 is, for example, 25 nm or more, may be 50 nm or more, or may be 100 nm or more. The thickness T3 of the conductive layer 50 is, for example, 100 μm or less, may be 50 μm or less, or may be 5 μm or less.
When the material of the conductive layer 50 has stretchability, the thickness T3 of the conductive layer 50 is, for example, 5 μm or more, may be 10 μm or more, or may be 20 μm or more. The thickness T3 of the conductive layer 50 is, for example, 60 μm or less, may be 50 μm or less, or may be 40 μm or less.

By devising the above-described material, thickness T3, and the like, it is possible to suppress deformation and breakage of the wiring 51 due to the deformation of the base material 20 . The arrangement of the wiring 51 may be devised as described below. By devising the arrangement of the wirings 51 , it is possible to prevent the wirings 51 from being deformed or damaged due to the deformation of the base material 20 .

As evidenced by the examples described later, the substrate 20 is likely to be greatly distorted around the corners of the first rigid member 30 . If the wiring 51 overlaps the area of the base material 20 in which large strain occurs, the wiring 51 is likely to be deformed or damaged. In this embodiment, it is proposed to arrange the wiring 51 in a region of the base material 20 in which a large strain is unlikely to occur.

The outline of the first rigid member 30 will be specifically described. As shown in FIGS. 3 and 4, the first rigid member 30 includes a first side 31 and a first corner 32 in plan view. The first side 31 extends linearly between the two first corners 32 . The first side 31 may include two eleventh sides 311 extending in the first direction D1 and two twelfth sides 312 extending in the second direction D2. The first corner 32 connects the eleventh side 311 and the twelfth side 312 . The first corner 32 extends in a direction different from that of the first side 31 . In the example shown in FIGS. 3 and 4, first rigid member 30 includes four first corners 32 .

FIG. 5 is a plan view showing an enlarged first corner 32 of FIG. The first corner 32 is chamfered on the side away from the center C1 of the first rigid member 30 in plan view. “Chamfered on the side away from the center C1” means that the intersection point P1 of the extension line EL1 of the two first sides 31 connected by the first corner 32 is located outside the first corner 32. means that The “outer side” is the side away from the center C1 in plan view.

The first corner 32 has a chamfer dimension R1. A chamfering dimension R1 in FIG. 5 is a chamfering dimension of the first corner 32 defined in relation to the twelfth side 312 . Chamfer dimension R1 is the distance between intersection point P1 and boundary point 322 in the direction in which twelfth side 312 extends. A boundary point 322 is located at the boundary between the twelfth side 312 and the first corner 32 . Although not shown, the chamfer dimension of the first corner 32 defined in relation to the eleventh side 311 is the distance between the intersection point P1 and the boundary point 321 in the direction in which the eleventh side 311 extends. A boundary point 321 is positioned at the boundary between the eleventh side 311 and the first corner 32 .

As shown in FIG. 5, the first corner 32 may be curved. In this case, the chamfer dimension R1 of the first corner 32 may be the radius of curvature of the first corner 32 .

The smaller the chamfer dimension R1 is, the more easily the substrate 20 is locally distorted around the first corner 32 . Therefore, it is preferable that the chamfer dimension R1 is equal to or greater than a predetermined value.

On the other hand, as the chamfer dimension R1 is larger, the dimension W1 of the first stable region 241 shown in FIGS. The first stable region 241 is a region of the base material 20 located around the first side 31 and in which distortion is suppressed. The first stable area 241 is part of the first peripheral area 24 . As shown in FIGS. 3 and 4, the first stable region 241 extends outward from the central portion of the first side 31 . For example, the first stable region 241 in contact with the twelfth side 312 extends outward from the central portion of the twelfth side 312 in the first direction D1. The direction in which the term "outer" is meant with respect to the first stable area 241 shown in FIG. 5 is represented by arrow D11.

In this embodiment, it is proposed to arrange the wiring 51 so as to pass through the first stable region 241 and reach the first overlapping region 23 . As a result, it is possible to prevent the wiring 51 from being deformed or damaged at the boundary between the first peripheral region 24 and the first overlapping region 23 . In order to sufficiently ensure the dimension W1 of the first stable region 241 in the direction in which the first side 31 extends, the chamfer dimension R1 is preferably equal to or less than a predetermined value. Thereby, for example, a plurality of wirings 51 can be arranged in the first stable region 241 . The dimension W1 can also be rephrased as the length of the central portion of the first side 31 with which the first stable region 241 is in contact.

The dimension W1 of the first stable region 241 may be calculated based on the following formula, as evidenced by the examples described below.
W1 = -1.1148 x R1 + 0.532 x K1
K1 is the dimension of the two first corners 32 and the first side 31 in the direction in which the first side 31 extends. When the first stable region 241 extends outward from the central portion of the twelfth side 312, the dimension K1 is the dimension of the two first corners 32 and the twelfth side 312 in the second direction D2, as shown in FIG. be.

The chamfer dimension R1 of the first corner 32 is, for example, 0.05 mm or more, may be 0.10 mm or more, or may be 0.20 mm or more. The chamfer dimension R1 of the first corner 32 is, for example, 1.5 mm or less, may be 1.0 mm or less, or may be 0.8 mm or less.

The chamfer dimension R1 of the first corner 32 may be determined based on the ratio to the dimension K1. R1/K1, which is the ratio of chamfer dimension R1 to dimension K1, is, for example, 0.020 or more, may be 0.025 or more, or may be 0.030 or more. R1/K1 is, for example, 0.30 or less, may be 0.25 or less, or may be 0.20 or less.

[First insulating layer]
The first insulating layer 70 will be described. The first insulating layer 70 is a layer having insulating properties. As shown in FIGS. 2 and 3, the first insulating layer 70 overlaps the first rigid member 30 in plan view. As shown in FIG. 3 , the contour of the first insulating layer 70 may lie inside the contour of the first rigid member 30 . The first insulating layer 70 partially covers the conductive layer 50 . For example, the first insulating layer 70 partially covers the wiring 51 and the pads 52 .

As shown in FIG. 3 , the first insulating layer 70 may have a first hole 71 penetrating through the first insulating layer 70 . The first hole 71 may overlap the conductive layer 50 . The conductive layer 50 overlapping the first hole 71 may constitute a pad 52 . In this case, the first hole 71 can define a region where the solder 54 is provided. As shown in FIG. 2 , pads 52 and electronic components 55 are electrically connected via solder 54 .

In FIG. 4, the outline of the first hole 71 is indicated by dotted lines. As shown in FIG. 4, the contour of pad 52 may surround the contour of first hole 71 . The outline of first hole 71 defines the outline of solder 54 .
When the wiring substrate 10 is deformed such as by bending, most of the conductive layer 50 is deformed so as to follow the deformation of the first rigid member 30 . On the other hand, the conductive layer 50 connected to the solder 54 would follow the solder 54 . Therefore, if the deformation of the first rigid member 30 is larger than the deformation of the solder 54 , a large stress is generated in the conductive layer 50 overlapping the outline of the solder 54 , and damage such as cracks may occur in the conductive layer 50 . be done.
In the example shown in FIG. 4, the contour of pad 52 surrounds the contour of first hole 71 . Therefore, even if the conductive layer 50 is damaged such as a crack along one side of the solder 54 contour, electrical connection between the conductive layer 50 and the solder 54 cannot be achieved on the other sides of the solder 54 contour. can be maintained. Thereby, the reliability of the wiring board 10 can be improved.

The material of the first insulating layer 70 is, for example, an organic resin such as polyimide, acryl, urethane, or epoxy, or an inorganic material such as SiO ₂ or alumina.

Next, the cross-sectional shape of the region of the wiring board 10 where the wiring 51 is formed will be described in detail. FIG. 6 is a diagram showing an example of a cross section of the wiring substrate 10. As shown in FIG.

Wiring board 10 includes above-described mountain portion 11 appearing on the surface of wiring board 10 on the first surface 21 side. The peak portion 11 is a portion of the surface of the wiring board 10 that protrudes in the normal direction of the first surface 21 . The structure including the ridges 11 is also referred to as a bellows-shaped portion 13 . The bellows-shaped portion may include valleys 12 located between two peaks 11 adjacent in the length direction D1.

As shown in FIG. 6, the wiring 51 includes a plurality of peaks 511 arranged in the length direction D1. The wiring 51 may include a valley portion 512 positioned between two peak portions 511 adjacent in the length direction D1. The peaks 511 and the valleys 512 appear in the portions of the wiring 51 overlapping the peaks 11 and the valleys 12 in plan view.

As will be described later, the wiring 51 is provided on the base material 20 in a state of being stretched by a first stretching amount under tension. When the tension is removed from the substrate 20 and the substrate 20 contracts, peaks 511 as shown in FIG. 6 are created.

A reference S11 represents the amplitude of the peaks 11 and the valleys 12 when the wiring board 10 is not under tension. In the example shown in FIG. 6, the wiring 51 is located on the surface of the wiring board 10, so the amplitude S11 is the amplitude of the peaks and valleys of the wiring 51. In the example shown in FIG. The amplitude S11 is, for example, 1 μm or more, and may be 10 μm or more. When the amplitude S<b>11 is 10 μm or more, the wiring 51 tends to deform following the elongation of the base material 20 . The amplitude S11 is, for example, 500 μm or less.

The amplitude of peaks and valleys is measured, for example, by measuring the distance in the normal direction of the substrate 20 between adjacent peaks and valleys over a certain range in the direction in which the peaks and valleys are aligned, Calculated by averaging them. The "fixed range in the direction in which the peaks and valleys are arranged" is, for example, 10 mm. As a measuring device for measuring the distance between adjacent peaks and valleys, a non-contact measuring device using a laser microscope or the like may be used, or a contact measuring device may be used. The dimensions of the elements of the wiring board 10 in plan view, such as the width W2 described above, may also be measured by a non-contact measuring instrument or a contact measuring instrument.
Based on an image such as a cross-sectional photograph, the distance between adjacent peaks and valleys may be measured. The dimensions of the elements of the wiring board 10 in the cross-sectional view, such as the thicknesses T1, T2, and T3 described above, are also measured based on an image such as a cross-sectional photograph. The width W2 and the like described above may be measured based on an image such as a cross-sectional photograph.

Reference character F11 represents the period of the peaks 11 and the valleys 12 when the wiring board 10 is not under tension. The period F11 is, for example, 10 μm or more, and may be 100 μm or more. The period F11 is, for example, 100 mm or less, and may be 10 mm or less. The period F11 of the ridges 11 and the troughs 12 is calculated by measuring intervals between the ridges 11 over a certain range in the direction in which the ridges 11 and the troughs 12 are arranged and averaging them.

Reference numerals M11 and M21 represent dimensions in the length direction D1 of the peaks 11 and the valleys 12, respectively, when the wiring board 10 is not under tension. In the example shown in FIG. 6, the dimension M11 of the peak portion 11 and the dimension M21 of the valley portion 12 are substantially the same. The ratio of the peaks 11 in the bellows-shaped portion 13 when the wiring board 10 is not under tension is represented by X1. The ratio X1 is calculated by M11/(M11+M21). The ratio X1 is, for example, 0.40 or more and 0.60 or less.

As shown in FIG. 6, the surface of the wiring board 10 on the second surface 22 side may also have a bellows-shaped portion 18 including a plurality of peaks 16 and valleys 17 aligned in the length direction D1. In the example shown in FIG. 6 , peak 16 appears at a position overlapping valley 512 , and valley 17 appears at a position overlapping peak 511 .

A reference S21 represents the amplitude of the peaks 16 and the valleys 17 when the wiring board 10 is not under tension. Amplitude S21 may be the same as or different from amplitude S11. For example, amplitude S21 may be smaller than amplitude S11. For example, the amplitude S21 may be 0.9 times or less, 0.8 times or less, or 0.6 times or less the amplitude S11. The amplitude S21 may be 0.1 times or more the amplitude S11, or may be 0.2 times or more. Note that "the amplitude S21 is smaller than the amplitude S11" is a concept that includes the case where peaks and valleys do not appear on the surface of the wiring board 10 on the second surface 22 side.

Reference character F21 represents the period of the peaks 16 and the valleys 17 when the wiring board 10 is not under tension. The period F21 may be the same as the period F11 of the peaks 11 and the valleys 12 .

FIG. 7 shows another example of a cross-sectional view of the wiring board 10. As shown in FIG. As shown in FIG. 7, the width M11 of the peak portion 11 may be smaller than the width M21 of the valley portion 12 when the wiring board 10 is not under tension. Such peaks 11 may occur, for example, when the peaks and valleys of the first surface 21 of the base material 20 are deformed over time and the influence of the deformation is transmitted to the bellows-shaped portion 13 . The width M11 of the peak portion 11 and the width M21 of the valley portion 12 are the width of the peak portion 11 and the width of the valley portion 12 at the center of the amplitude S11. The width M11 of the peak portion 11 is preferably 0.3 times or more the width M21 of the valley portion 12, may be 0.5 times or more, or may be 0.7 times or more. The width M11 of the peak portion 11 may be less than 1.0 times the width M21 of the valley portion 12, may be 0.9 times or less, may be 0.8 times or less, or may be 0.8 times or less. It may be 7 times or less.

FIG. 8 is a plan view showing an example of the ridges 11 of the bellows-shaped portion 13 formed on the wiring substrate 10. FIG. In the example shown in FIG. 8, the plurality of peaks 11 of the bellows-shaped portion 13 are arranged along the first direction D1 in which the wiring 51 extends. As shown in FIG. 8, each peak 11 may extend in a direction orthogonal to the direction in which the wiring 51 extends, or may extend in a direction inclined with respect to the direction orthogonal to the direction in which the wiring 51 extends. .

FIG. 9 shows another example of a cross-sectional view of the wiring board 10. As shown in FIG. As shown in FIG. 9 , the period F21 of the peaks 16 and the valleys 17 may be greater than the period F11 of the peaks 11 and the valleys 12 . For example, the period F21 may be 1.1 times or more, 1.2 times or more, 1.5 times or more, or 2.0 times or more the period F11. good too. Note that “the period F21 is longer than the period F11” is a concept that includes the case where peaks and valleys do not appear on the surface of the wiring board 10 on the second surface 22 side.

FIG. 10 shows another example of a cross-sectional view of the wiring board 10. As shown in FIG. As shown in FIG. 10, the positions of the peaks 16 and the valleys 17 may be shifted by J from the positions of the valleys 12 and the peaks 11 . The deviation amount J is, for example, 0.1×F11 or more, and may be 0.2×F11 or more.

(Method for manufacturing wiring board)
Next, a method for manufacturing the wiring board 10 will be described with reference to FIGS. 11A to 11C.

First, as shown in FIG. 11A, a substrate preparation step of preparing the substrate 20 is performed. Reference L0 represents the dimension in the first direction D1 of the base material 20 in a non-tensioned state.

Subsequently, as shown in FIG. 11B, a first elongation step of elongating the base material 20 is performed. The first elongation step applies a first tension H1 to the substrate 20 in the first direction D1 to elongate the substrate 20 to the dimension L1. In the first stretching step, tension may be applied to the substrate 20 in the first direction D1 and in a direction crossing the first direction D1. For example, in the first stretching step, tension may be applied to the substrate 20 in the first direction D1 and the second direction D2.

The elongation rate (=(L1−L0)×100/L0) of the base material 20 in the first direction D1 is, for example, 10% or more, and may be 30% or more. The elongation rate of the base material 20 is, for example, 200% or less, and may be 100% or less. The elongation step may be performed while the substrate 20 is heated, or may be performed at room temperature. When heating the base material 20, the temperature of the base material 20 is 50 to 100 degreeC, for example.

Subsequently, as shown in FIG. 11B, a wiring forming step is performed. In the wiring forming step, the wiring 51 is provided on the first surface 21 of the base material 20 stretched by the first tension H1 in the first stretching step. For example, a conductive paste containing a base material and conductive particles is printed on the first surface 21 of the substrate 20 .

After that, a first contraction step is performed to remove the first tension H from the substrate 20 . Thereby, the base material 20 shrinks in the first direction D1, as indicated by an arrow C in FIG. 11C. When the base material 20 shrinks, the wiring 51 is also deformed. The deformation of the wiring 51 occurs as a bellows-shaped portion as described above. Thus, the wiring substrate 10 with the bellows-shaped portion exposed can be obtained.

Subsequently, as shown in FIG. 12A, a first insulating layer 70 may be formed. For example, a layer of material forming the first insulating layer 70 is formed on the first surface 21 by a printing method. Subsequently, the layer is processed by photolithography or the like. Thereby, it is possible to obtain the first insulating layer 70 having a predetermined contour and having the first hole 71 formed therein.

Subsequently, the electronic component 55 may be mounted on the wiring board 10 . For example, as shown in FIG. 12B, paste-like solder 54 is provided in the first holes 71 . Subsequently, the electronic component 55 is arranged on the first insulating layer 70 so that the terminals of the electronic component 55 are positioned on the solder 54 . Subsequently, the solder 54 is heated. Thereby, the pad 52 and the electronic component 55 can be electrically connected via the solder 54 . Thus, as shown in FIG. 2, the wiring board 10 on which the electronic component 55 is mounted can be obtained.

According to the present embodiment, wiring 51 of wiring board 10 has a plurality of peaks 511 . When the base material 20 of the wiring board 10 expands, the wiring 51 can follow the elongation of the base material 20 by deforming so as to reduce the amplitude of the peaks 511 . Therefore, it is possible to suppress an increase in the total length of the wiring 51 and a decrease in the cross-sectional area of the wiring 51 due to the elongation of the base material 20 . As a result, it is possible to suppress an increase in the resistance value of the wiring 51 due to the elongation of the wiring board 10 . Moreover, it is possible to suppress the occurrence of damage such as cracks in the wiring 51 .

An example of the effect related to the resistance value of the wiring 51 will be described. The electrical resistance value of the wiring 51 in the first state in which no tension is applied to the wiring board 10 in the first direction D1 is referred to as the first electrical resistance value. Also, the resistance value of the wiring 51 in the second state in which the wiring substrate 10 is tensioned in the first direction D1 is referred to as a second electrical resistance value. In the second state, wiring board 10 is elongated by 30% compared to the first state. According to the present embodiment, by forming the bellows-shaped portion in the wiring 51, the ratio of the absolute value of the difference between the first electrical resistance value and the second electrical resistance value to the first electrical resistance value can be reduced. The ratio is, for example, 20% or less, more preferably 10% or less, and even more preferably 5% or less.

FIG. 13 is an enlarged cross-sectional view showing wiring board 10 in a third state in which wiring board 10 is stretched by 25% compared to the first state by applying tension to wiring board 10 in first direction D1. Symbols S12 and F12 represent the amplitude and period of the bellows-shaped portion 13 in the third state. Symbols S22 and F22 represent the amplitude and period of the bellows-shaped portion 18 in the third state. The amplitude S12 in the third state is, for example, 0.8 times or less the amplitude S11 in the first state, may be 0.7 times or less, or may be 0.6 times or less. The amplitude S12 is, for example, 0.2 times or more the amplitude S11, may be 0.3 times or more, or may be 0.4 times or more.

Symbols M12 and M22 respectively represent the dimensions in the length direction D1 of the peaks 11 and the valleys 12 in the third state. The dimension M12 and the dimension M22 in the third state are larger than the dimension M11 of the peak portion 11 and the dimension M21 of the valley portion 12 in the first state.

When the wiring substrate 10 is stretched, the dimensions of the peaks 11 and the valleys 12 may increase while maintaining the ratio between them. The ratio of peaks 11 in the third state is represented by symbol X2. The ratio X2 is calculated by M12/(M12+M22). The ratio X2 is equivalent to X1 described above in the first state, and is, for example, 0.40 or more and 0.60 or less. Further, the absolute value of the difference between the ratio X1 and the ratio X2 is, for example, 0.20 or less, may be 0.15 or less, may be 0.10 or less, or may be 0.08 or less. It may be 0.06 or less, or 0.04 or less.

Further, according to this embodiment, the wiring 51 is arranged in the first stable region 241 . Therefore, it is possible to prevent the wiring 51 from being deformed or damaged at the boundary between the first peripheral region 24 and the first overlapping region 23 . Moreover, since the ratio of the chamfered dimension R1 of the first corner 32 to the dimension K1 of the first rigid member 30 is 0.020 or more, the dimension W1 of the first stable region 241 can be sufficiently ensured. Therefore, two or more wires 51 can reach the first overlapping region 23 through the first stable region 241 .

Applications of the wiring board 10 include, for example, the healthcare field, the medical field, the nursing field, the electronics field, the sports/fitness field, the beauty field, the mobility field, the livestock/pet field, the amusement field, the fashion/apparel field, the security field, and the military field. distribution, education, building materials/furniture/decoration, environmental energy, agriculture, forestry and fisheries, and robots. For example, a product to be attached to a part of the human body such as an arm is constructed using the wiring board 10 according to the present embodiment. Since the wiring board 10 can be stretched, for example, by attaching the wiring board 10 to the body in a stretched state, the wiring board 10 can be brought into closer contact with a part of the body. Therefore, it is possible to realize a good wearing feeling. In addition, since it is possible to suppress the decrease in the electrical resistance value of the wiring 51 when the wiring board 10 is elongated, it is possible to realize good electrical characteristics of the wiring board 10 . In addition, since the wiring board 10 can be stretched, it can be installed or incorporated along a curved surface or a three-dimensional shape as well as a living body such as a human being. Examples of such products include vital sensors, masks, hearing aids, toothbrushes, plasters, poultices, contact lenses, artificial hands, artificial legs, artificial eyes, catheters, gauze, drug packs, bandages, disposable bioelectrodes, diapers, rehabilitation equipment, and household appliances. , displays, signage, personal computers, mobile phones, mice, speakers, sportswear, wristbands, headbands, gloves, swimwear, supporters, balls, gloves, rackets, clubs, bats, fishing rods, relay batons, gymnastics equipment, and Grips, equipment for physical training, floats, tents, swimwear, bibs, goal nets, goal tapes, medical solution penetration beauty masks, electrical stimulation diet products, pocket warmers, false nails, tattoos, automobiles, airplanes, trains, ships, bicycles, Strollers, drones, wheelchairs, seats, instrument panels, tires, interiors, exteriors, saddles, handles, roads, rails, bridges, tunnels, gas and water pipes, electric wires, tetrapods, rope collars, leads, harnesses, animals tags, bracelets, belts, etc., game consoles, haptic devices such as controllers, luncheon mats, tickets, dolls, stuffed animals, support goods, hats, clothes, glasses, shoes, insoles, socks, stockings, slippers, innerwear, mufflers , earmuffs, bags, accessories, rings, watches, neckties, personal ID recognition devices, helmets, packages, IC tags, plastic bottles, stationery, books, pens, carpets, sofas, bedding, lighting, doorknobs, handrails, vases, beds , mattresses, cushions, curtains, doors, windows, ceilings, walls, floors, batteries, vinyl houses, nets, robot hands, robot exteriors, etc.

Various modifications can be made to the first embodiment described above. Modifications will be described below with reference to the drawings as necessary. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding portions in the first embodiment are used for the portions that can be configured in the same manner as in the first embodiment. , and overlapping explanations are omitted. Further, when it is clear that the effects obtained in the first embodiment can also be obtained in the modified example, the description thereof may be omitted.

(First modification)
FIG. 14 is a plan view of wiring board 10 according to the first modification. FIG. 15 is a cross-sectional view of the wiring substrate 10 of FIG. 14 taken along line BB. As shown in FIGS. 14 and 15, the wiring board 10 may include a second insulating layer 75 that at least partially overlaps the wiring 51 in plan view. In the example shown in FIG. 14, the second insulating layer 75 extends along the wiring 51 .

[Control layer]
The second insulating layer 75 is a layer provided to control expansion and contraction of the base material 20 . The second insulating layer 75 has insulating properties. A second insulating layer 75 may be located on the first peripheral region 24 of the substrate 20 . The second insulating layer 75 is arranged so as to overlap the wiring 51 or be close to the wiring 51 when viewed along the normal direction of the first surface 21 . The second insulating layer 75 may overlap the entire wiring 51 .

The second insulating layer 75 may have an elastic modulus higher than that of the substrate 20 . The elastic modulus of the second insulating layer 75 is, for example, 100 MPa or more, may be 1 GPa or more, or may be 10 GPa or more. The elastic modulus of the second insulating layer 75 is, for example, 1.1 times or more, may be 2 times or more, may be 10 times or more, or may be 100 times or more that of the base material 20. good too.

The elastic modulus of the second insulating layer 75 may be equal to or lower than the elastic modulus of the base material 20 . The elastic modulus of the second insulating layer 75 is, for example, 1.0 times or less, may be 0.9 times or less, or may be 0.8 times or less that of the base material 20 .

The material of the second insulating layer 75 may or may not have elasticity. If the second insulating layer 75 contains a stretchable material, the second insulating layer 75 can be resistant to deformation.

An example of a non-stretchable material used for the second insulating layer 75 is resin. As the resin, a general resin can be used, and for example, any of thermoplastic resin, thermosetting resin, photo-setting resin and the like can be used. When the second insulating layer 75 contains resin or elastomer, the second insulating layer 75 may be made of a resin base material.

The stretchability of the material used for the second insulating layer 75 may be the same as or equal to the stretchability of the substrate 20 .
An example of a stretchable material is an elastomer. As the elastomer, general thermoplastic elastomers and thermosetting elastomers can be used. Examples of elastomers include styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, amide-based elastomers, silicone rubbers, urethane rubbers, fluororubbers, polybutadiene, polyisobutylene, polystyrene-butadiene, and polychloroprene. When the material forming the second insulating layer 75 is these resins, the second insulating layer 75 may have transparency. The second insulating layer 75 may have a light blocking property, for example, a property of blocking ultraviolet rays. For example, the second insulating layer 75 may be black. The color of the second insulating layer 75 and the color of the substrate 20 may be the same or different.

The thickness T4 of the second insulating layer 75 may be any thickness that can withstand expansion and contraction, and is appropriately selected according to the material of the second insulating layer 75 and the like. The thickness T4 of the second insulating layer 75 is, for example, 0.1 μm or more, may be 1 μm or more, or may be 10 μm or more. The thickness of the second insulating layer 75 is, for example, 5 mm or less, may be 1 mm or less, may be 500 μm or less, or may be 100 μm or less. If the second insulating layer 75 is too thin, the effect of controlling the period of the accordion-shaped portion may not be sufficiently obtained. Further, if the second insulating layer 75 is too thick, even if the elastic modulus of the second insulating layer 75 satisfies the above relationship, the flexural rigidity of the second insulating layer 75 increases and the stretchability of the wiring board 10 decreases. It may happen.

A method for forming the second insulating layer 75 is appropriately selected according to the material and the like. For example, after the wiring 51 is formed on the base material 20 or on the support substrate 40 described later, the material forming the second insulating layer 75 may be provided on the wiring 51 by a printing method. A member such as a resin film forming the second insulating layer 75 may be attached to the base material 20 or the support substrate 40 via an adhesive layer or the like.

The adhesive layer for attaching the second insulating layer 75 to the base material 20 or the support substrate 40 may be a molecular adhesive layer. The term "molecular adhesion" refers to the application of a molecular adhesive compound between two adherends to bond the two adherends by chemical bonding.

A known molecular adhesive can be used as the molecular adhesive used for the molecular adhesive layer, and the molecular adhesive is appropriately selected according to the use of the wiring board 10 and the like. Examples include silane coupling agents and thiol compounds. The thickness of the molecular adhesion layer is, for example, about several nm to 100 nm.

(Second modification)
Although the first rigid member 30 is positioned on the second surface 22 side of the base material 20 in the first embodiment described above, the arrangement of the first rigid member 30 is not particularly limited.
For example, as shown in FIG. 16, the first rigid member 30 may be embedded in the base material 20 . In this case, the first rigid member 30 does not have to be exposed on either the first surface 21 or the second surface 22 of the base material 20 . Alternatively, the first rigid member 30 may be exposed on the first surface 21 or the second surface 22 of the base material 20 . For example, as shown in FIG. 17, the first rigid member 30 may be exposed on the first surface 21 .
Also, although not shown, the first rigid member 30 may be positioned on the first surface 21 side of the base material 20 .

(Third modification)
In the first embodiment, an example in which the wiring 51 is provided on the base material 20 was shown, but the present invention is not limited to this. This modified example shows an example in which the wiring 51 is supported by a support substrate.

FIG. 18 is a cross-sectional view of wiring board 10 according to a first modification. The wiring board 10 includes a base material 20 , a first rigid member 30 , a support substrate 40 and a conductive layer 50 . The wiring board 10 may include a first insulating layer 70 .

[Supporting substrate]
The support substrate 40 is a member configured to have lower stretchability than the base material 20 . The support substrate 40 includes a second surface 42 facing the base material 20 and a first surface 41 located on the opposite side of the second surface 42 . In the example shown in FIG. 18, the conductive layer 50 including the wiring 51 and the pads 52 is positioned on the first surface 41 side of the support substrate 40 . A second surface 42 of the support substrate 40 is bonded to the base material 20 .

Although not shown, the conductive layer 50 may be positioned on the second surface 42 side of the support substrate 40 .

An adhesive layer 45 containing an adhesive may be provided between the base material 20 and the support substrate 40 . Examples of adhesives that can be used include acrylic adhesives, silicone adhesives, siloxane primers, thiol primers, and the like. A molecular film of HMDSO (hexamethyldisiloxane), HMDS (hexamethyldisilazane), or the like, which is produced by a vapor phase method, may be used as the adhesive layer 45 . The thickness of the adhesive layer 45 is, for example, 5 μm or more and 200 μm or less.

FIG. 19 is an example of a cross-sectional view of the wiring board 10 in the direction in which the wiring 51 extends. In this modification, when the tension is removed from the base material 20 bonded to the support substrate 40 and the base material 20 contracts, the peaks and valleys similar to the peaks 511 and valleys 512 of the wiring 51 are supported. It also appears on the substrate 40 . The characteristics and dimensions of the support substrate 40 are set to facilitate the formation of such peaks and valleys. For example, the support substrate 40 has an elastic modulus greater than that of the base material 20 .

The elastic modulus of the support substrate 40 is, for example, 100 MPa or more, may be 1 GPa or more, or may be 10 GPa or more. The elastic modulus of the support substrate 40 is, for example, 10 times or more, may be 100 times or more, or may be 1000 times or more that of the base material 20 . The elastic modulus of the support substrate 40 is, for example, 50000 times or less, may be 10000 times or less, or may be 5000 times or less than the elastic modulus of the base material 20 . By setting the elastic modulus of the support substrate 40 in this way, it is possible to prevent the period F11 of the peaks 511 and the valleys 512 from becoming too small. Moreover, it is possible to suppress the occurrence of local bending in the peak portions 511 and the valley portions 512 .
If the modulus of elasticity of the support substrate 40 is too low, the support substrate 40 is likely to deform during the process of forming the wirings 51 , and as a result, alignment of the wirings 51 with respect to the support substrate 40 becomes difficult. Further, if the elastic modulus of the support substrate 40 is too high, it becomes difficult to restore the base material 20 when relaxed, and the base material 20 is likely to crack or break.

The thickness T5 of the support substrate 40 is, for example, 500 nm or more, and may be 1 μm or more. The thickness T5 of the support substrate 40 is, for example, 10 μm or less, and may be 5 μm or less. If the thickness T5 of the support substrate 40 is too small, it becomes difficult to handle the support substrate 40 in the process of manufacturing the support substrate 40 and the process of forming members such as the wirings 51 on the support substrate 40 . If the thickness T5 of the support substrate 40 is too large, it becomes difficult to restore the base material 20 during relaxation, and the desired expansion and contraction of the base material 20 cannot be obtained.

The support substrate 40 may contain, for example, resin such as polyethylene naphthalate, polyimide, polyethylene terephthalate, polycarbonate, and acrylic resin. Polyethylene naphthalate or polyimide is excellent in durability and heat resistance and is preferably used.

As a method of calculating the elastic modulus of the support substrate 40, a method of performing a tensile test in accordance with ASTM D882 using a sample of the support substrate 40 can be adopted.

(Method for manufacturing wiring board)
Next, with reference to FIGS. 20A to 20D, a method for manufacturing the wiring board 10 according to this modification will be described.

First, as shown in FIG. 20A, a support substrate 40 is prepared. A support substrate 40 may be placed over a carrier substrate 80 . Subsequently, as shown in FIG. 20A, a conductive layer 50 is provided on the first surface 41 of the support substrate 40 . For example, first, a conductive layer such as a copper layer is formed on the first surface 41 of the support substrate 40 by vapor deposition, plating, or the like. Subsequently, the layer is processed using photolithographic and etching methods. Thereby, the conductive layer 50 forming the wiring 51 can be formed on the first surface 41 . A first insulating layer 70 may then be formed as shown in FIG. 20A. Although not shown, the first insulating layer 70 may be formed after the support substrate 40 is bonded to the base material 20 .

Subsequently, the support substrate 40 is removed from the carrier substrate 80 as indicated by the arrow in FIG. 20B. For example, first, the adhesive film 85 is attached to the support substrate 40 . Then, the adhesive film 85 is lifted. This removes the support substrate 40 from the carrier base 80 .

Subsequently, as shown in FIG. 20C, a first elongation step of elongating the base material 20 is performed. Then, a wiring formation process is implemented. In the wiring forming step, the second surface 42 of the support substrate 40 provided with the wiring 51 is joined to the first surface 21 of the base material 20 in the extended state. An adhesive layer 45 may be provided between the base material 20 and the support substrate 40 .

Subsequently, as shown in FIG. 20D, the adhesive film 85 is removed from the support substrate 40. Then, as shown in FIG. After that, a first contraction step is performed to remove the first tension H1 from the base material 20 . Thereby, the base material 20 contracts in the first direction D1. When the base material 20 shrinks, the support substrate 40 and the wiring 51 are also deformed. Deformation of the support substrate 40 and the wiring 51 occurs as a bellows-shaped portion as described above. Thus, the wiring substrate 10 including the support substrate 40 can be obtained. After that, the electronic component 55 may be mounted on the wiring board 10 as in the case of the first embodiment.

Also in this modified example, by arranging the wiring 51 in the first stable region 241 , it is possible to prevent the wiring 51 from being deformed or damaged at the boundary between the first surrounding region 24 and the first overlapping region 23 .

(Fourth modification)
FIG. 21 is a cross-sectional view showing a wiring board 10 according to a fourth modification. As shown in FIG. 21, the wiring board 10 including the support substrate 40 may include a second insulating layer 75 that at least partially overlaps the wiring 51 in plan view.

(Fifth Modification)
FIG. 22 is a cross-sectional view showing a wiring board 10 according to a fifth modification. As shown in FIG. 22 , wiring board 10 may include protective layer 60 that covers electronic component 55 . The protective layer 60 may extend to a region that does not overlap the electronic component 55 in plan view. For example, the protective layer 60 may be located outside the first rigid member 30 in plan view and may overlap the wiring 51 . In the example of FIG. 22, the protective layer 60 extends over the entire wiring board 10 .

The wiring board 10 having the protective layer 60 may have a support substrate 40 as shown in FIG. Although not shown, the wiring board 10 including the protective layer 60 may not include the support substrate 40 .

The protective layer 60 may have insulating properties. Like the base material 20, the protective layer 60 may have stretchability. The elastic modulus of the protective layer 60 is, for example, 10 MPa or less, and may be 1 MPa or less. The elastic modulus of the protective layer 60 is, for example, 1 kPa or more, and may be 10 kPa or more.

As a method of calculating the elastic modulus of the protective layer 60, a method of performing a tensile test in accordance with JIS K6251 using a sample of the protective layer 60 can be adopted. Alternatively, a method of measuring the elastic modulus of a sample of the protective layer 60 by a nanoindentation method in compliance with ISO14577 may be employed.

Like the base material 20, the protective layer 60 may contain an elastomer as a main component. As the material of the protective layer 60, the materials exemplified for the base material 20 can be used. The thickness T6 of the protective layer 60 is, for example, 10 μm, may be 20 μm or more, or may be 30 μm or more. The thickness T6 of the protective layer 60 is, for example, 10 mm or less, may be 3 mm or less, or may be 1 mm or less.

A method for forming the protective layer 60 is appropriately selected according to the material and the like. For example, after providing the electronic component 55 on the base material 20 or the support substrate 40, the material forming the protective layer 60 may be formed by a printing method. A member such as a resin film that constitutes the protective layer 60 may be attached to the base material 20 or the support substrate 40 via an adhesive layer or the like.

(Sixth modification)
FIG. 23 is a cross-sectional view showing a wiring board 10 according to a sixth modification. As shown in FIG. 23, wiring board 10 may include at least one second rigid member 35 . The wiring board 10 may include two or more second rigid members 35 . The second rigid member 35 is interposed between the conductive layer 50 and the electronic component 55 and is a member having higher rigidity than the base material 20 . As shown in FIG. 23, the second rigid member 35 may be provided with a conductor 38 .

The second rigid member 35 and conductor 38 constitute, for example, a printed circuit board. In this case, the second rigid member 35 is a substrate such as a glass epoxy substrate. The conductor 38 is a wiring, a through electrode, or the like formed on the substrate. The conductor 38 is connected to a terminal (not shown) of the electronic component 55 . The electronic component 55 is electrically connected to the wiring 51 via the conductor 38 . For example, conductor 38 is connected to solder 54 . In this case, the electronic component 55 is electrically connected to the wiring 51 via the conductor 38 , the solder 54 and the pad 52 .

A parameter representing the rigidity of the second rigid member 35 is, for example, an elastic modulus. The elastic modulus of the second rigid member 35 may be higher than the elastic modulus of the base material 20 . The elastic modulus of the second rigid member 35 is, for example, 10 times or more, may be 100 times or more, or may be 1000 times or more that of the base material 20 . The elastic modulus of the second rigid member 35 is, for example, 10000 times or less, and may be 50000 times or less, that of the base material 20 . The elastic modulus of the second rigid member 35 is, for example, 1 GPa or more, and may be 10 GPa or more. As a method of calculating the modulus of elasticity of the second rigid member 35, a method of performing a tensile test according to ASTM D882 using a sample of the first rigid member 30 can be adopted.

The second rigid member 35 is composed of a metal layer containing a metal material, a general thermoplastic elastomer, an oligomer such as acrylic, urethane, epoxy, polyester, epoxy, vinyl ether, polyene/thiol, and silicone. , polymers, and the like. Metal materials are, for example, copper, aluminum, stainless steel, and the like. The second rigid member 35 may be a base material used in printed circuit boards. Base materials used in printed circuit boards are glass epoxy, paper phenol, and the like. Glass epoxy is glass fiber impregnated with epoxy resin. Paper phenol is paper impregnated with phenolic resin.

The wiring board 10 including the second rigid member 35 may include a support substrate 40 as shown in FIG. Although not shown, the wiring board 10 including the second rigid member 35 may not include the support substrate 40 .

(Seventh Modification)
FIG. 24 is a cross-sectional view showing a wiring board 10 according to a seventh modification. As shown in FIG. 24, the wiring board 10 including the second rigid member 35 may include the protective layer 60 described above.

The elastic modulus of the second rigid member 35 may be higher than the elastic modulus of the protective layer 60 . The elastic modulus of the second rigid member 35 is, for example, 10 times or more, may be 100 times or more, or may be 1000 times or more that of the protective layer 60 . The elastic modulus of the second rigid member 35 is, for example, 10000 times or less, and may be 50000 times or less, that of the protective layer 60 .

When a force such as tension is applied to the wiring board 10 , the area of the protective layer 60 overlapping the second rigid member 35 is deformed such as expansion and contraction compared to the area of the protective layer 60 not overlapping the second rigid member 35 . unlikely to occur. In the following description, the area of the protective layer 60 that overlaps the second rigid member 35 in plan view is also referred to as a second overlap area 63, and the area of the protective layer 60 that does not overlap the second rigid member 35 in plan view is referred to as the second overlap area. Also referred to as peripheral region 64 .

When the wiring substrate 10 is deformed, the protective layer 60 is also deformed such as strain. If the wiring 51 overlaps the area of the protective layer 60 where large strain occurs, the wiring 51 is likely to be deformed or damaged. In this modified example, it is proposed to arrange the wiring 51 in a region of the protective layer 60 in which large strain is unlikely to occur.

The outline of the second rigid member 35 will be specifically described. FIG. 25 is a plan view showing the wiring substrate 10. FIG. The second rigid member 35 includes a second side 36 and a second corner 37 in plan view. The second side 36 extends linearly between the two second corners 37 . The second side 36 may include two 21st sides 361 extending in the first direction D1 and two 22nd sides 362 extending in the second direction D2. The second corner 37 connects the 21st side 361 and the 22nd side 362 . The second corner 37 extends in a direction different from that of the second side 36 . In the example shown in FIG. 25 the second rigid member 35 includes four second corners 37 .

As with the first corner 32 of the first rigid member 30, the second corner 37 is also chamfered on the side away from the center C2 of the second rigid member 35 in plan view. The second corner 37 has a chamfer dimension R2. Chamfer dimension R2 is defined similarly to chamfer dimension R1 of first corner 32 . For example, the chamfering dimension R2 of the second corner 37 defined in relation to the 22nd side 362 is the distance between the intersection point and the boundary point in the direction in which the 22nd side 362 extends. The boundary point is located at the boundary between the 22nd side 362 and the second corner 37 . The intersection point is the point where extensions of the two second sides 36 connected by the second corner 37 intersect.

The second corner 37 may be curved. In this case, the chamfer dimension R2 of the second corner 37 may be the radius of curvature of the second corner 37 .

The smaller the chamfer dimension R2 is, the more easily the protective layer 60 is distorted around the second corner 37 . Therefore, it is preferable that the chamfer dimension R2 is equal to or greater than a predetermined value.

On the other hand, the larger the chamfer dimension R2, the smaller the dimension W2 of the second stable region 641. The second stable region 641 is a region of the protective layer 60 located around the second side 36 and in which distortion is suppressed. The second stable area 641 is part of the second peripheral area 64 . The second stable region 641 extends outward from the central portion of the second side 36 . For example, the second stable region 641 in contact with the 22nd side 362 extends outward from the central portion of the 22nd side 362 in the first direction D1.

In this modified example, it is proposed to arrange the wiring 51 so as to pass through the second stable region 641 and reach the second overlapping region 63 . As a result, it is possible to prevent the wiring 51 from being deformed or damaged at the boundary between the second peripheral region 64 and the second overlapping region 63 . In order to sufficiently secure the dimension W2 of the second stable region 641 in the direction in which the second side 36 extends, it is preferable that the chamfer dimension R2 is equal to or less than a predetermined value. Thereby, for example, a plurality of wirings 51 can be arranged in the second stable region 641 .

The dimension W2 of the second stable region 641 may be calculated based on the following formula, similarly to the dimension W1 of the first stable region 241.
W2 = -1.1148 x R2 + 0.532 x K2
K2 is the dimension of the two second corners 37 and the second side 36 in the direction in which the second side 36 extends. When the second stable area 641 extends outward from the central portion of the twenty-second side 362, the dimension K2 is the dimension of the two second corners 37 and the twenty-second side 362 in the second direction D2.

The chamfer dimension R2 of the second corner 37 is, for example, 0.05 mm or more, may be 0.10 mm or more, or may be 0.20 mm or more. The chamfer dimension R2 of the second corner 37 is, for example, 1.5 mm or less, may be 1.0 mm or less, or may be 0.8 mm or less.

Chamfer dimension R2 of second corner 37 may be determined based on a ratio to dimension K2. R2/K2, which is the ratio of chamfer dimension R2 to dimension K2, is, for example, 0.020 or more, may be 0.025 or more, or may be 0.030 or more. R2/K2 is, for example, 0.30 or less, may be 0.25 or less, or may be 0.20 or less.

According to this modification, the wiring 51 is arranged in the second stable region 641 . Therefore, it is possible to prevent the wiring 51 from being deformed or damaged at the boundary between the second peripheral region 64 and the second overlapping region 63 . Moreover, since the ratio of the chamfered dimension R2 of the second corner 37 to the dimension K2 of the second rigid member 35 is 0.020 or more, the dimension W2 of the second stable region 641 can be sufficiently ensured. Therefore, two or more wires 51 can reach the second overlapping region 63 through the second stable region 641 .

(Eighth modification)
FIG. 26 is a cross-sectional view showing a wiring board 10 according to an eighth modification. As shown in FIG. 26 , the wiring board 10 including the second rigid member 35 and the protective layer 60 may not include the first rigid member 30 . In this case, the wiring board 10 may include the support substrate 40 as shown in FIG. 26, and the wiring board 10 may not include the support substrate 40 as shown in FIG. Even if the wiring board 10 does not include the first rigid member 30 , the second rigid member 35 can prevent the wiring 51 from being deformed or damaged.

(Ninth modification)
Although the first corner 32 of the first rigid member 30 is curved in the above-described embodiment and modification, the present invention is not limited to this. As shown in FIG. 28, the first corner 32 may extend linearly from the boundary point 321 to the boundary point 322 . Although not shown, the second corner 37 of the second rigid member 35 may also extend linearly like the first corner 32 of FIG.

(Tenth Modification)
In the above-described embodiment and modified example, an example in which the four first sides 31 of the first rigid member 30 have the same length is shown, but the present invention is not limited to this. As shown in FIG. 29, the four first sides 31 of the first rigid member 30 may have different lengths. For example, the eleventh side 311 extending in the first direction D1 may be longer than the twelfth side 312 extending in the second direction D2. Although not shown, the four second sides 36 of the second rigid member 35 may also have different lengths like the four first sides 31 of FIG.

(11th modification)
Although the first rigid member 30 includes three first sides 31 and three first corners 32 in the above-described embodiment and modification, the present invention is not limited to this. As shown in FIG. 30 , the first rigid member 30 may include three first sides 31 and three first corners 32 . Although not shown, first rigid member 30 may include five or more first corners 32 . The number of first sides 31 and the number of first corners 32 of the first rigid member 30 may be the same or different.
Although not shown, the second rigid member 35 may include three second sides 36 and three second corners 37 similar to the first rigid member 30 of FIG. Although not shown, the second rigid member 35 may include five or more second corners 37 . The number of second sides 36 and the number of second corners 37 of the second rigid member 35 may be the same or different.

The above embodiments and modifications may be combined as appropriate.

The present invention will be specifically described based on examples. The present invention is not limited to the description of the following examples as long as the gist thereof is not exceeded.

[Example 1]
A simulation was performed to calculate the volumetric strain that occurs in the base material 20 when the laminate including the base material 20 and the first rigid member 30 that partially overlaps the base material 20 is stretched in the first direction D1 and the second direction D2. . The elongation rate of the laminate in the first direction D1 and the second direction D2 is 150%. 31 and 32 are a plan view and a cross-sectional view showing the laminate. The parameters of the base material 20 and the first rigid member 30 set in the simulation are as follows.
- Modulus of elasticity of base material 20: 0.1 MPa
・Elastic modulus of the first rigid member 30: 1 GPa
・Dimension K1 of the first rigid member 30: 4 mm
- Curvature radius R1 of the first corner 32 of the first rigid member 30: 0.5 mm

The calculated volumetric strain is shown in FIGS. 33A and 33B. FIG. 33A is a plan view expressing the volumetric strain at each position of the laminate by pixel density. FIG. 33B is a graph showing volumetric strain at each point on the horizontal axis x of FIG. 33A. A point V1 on the horizontal axis x is located at the center of the eleventh side 311 in the first direction D1. The point V2 is located on the extended line of the eleventh side 311 and sufficiently separated from the first corner 32 . The distance from point V1 to point V2 is 1.25 times the dimension K1 of the first rigid member 30 .

As shown in FIGS. 33A and 33B, a large volume strain is generated in the base material 20 around the first corner 32 . At point V2, almost no volume strain due to the first corner 32 was observed. A point V3 is a point on the 11th side 311 where the same volumetric strain as the volumetric strain at the point V2 is calculated. Almost no volumetric strain due to the first corner 32 was observed between the point V1 and the point V2. Therefore, the area of the base material 20 extending outward from the portion of the eleventh side 311 from point V1 to point V3 is the first stable area 241 described above.

As indicated by the dotted line in FIG. 33B, at a point on the eleventh side 311 located on the opposite side of the point V1 to the point V3, a symmetric volumetric strain graph centering on the point V1 can be obtained. Conceivable. Accordingly, the area of the base material 20 extending outward from the portion of the eleventh side 311 from point V1 to point V4 is also considered to be the first stable area 241 described above. The point V4 is located symmetrically with the point V3 with respect to the point V1. Therefore, dimension W1 of first stable area 241 is twice the distance from point V1 to point V3. The dimension W1 was 1.6 mm.

[Example 2]
The same simulation as in Example 1 was performed by changing the curvature radius R1 of the first corner 32 of the first rigid member 30 to 0.1 mm. The dimension W1 of the first stable area 241 was 2.0 mm.

[Example 3]
The same simulation as in Example 1 was performed by changing the curvature radius R1 of the first corner 32 of the first rigid member 30 to 1.0 mm. The dimension W1 of the first stable region 241 was 1.0 mm.

[Example 4]
The same simulation as in Example 1 was performed with the dimension K1 of the first rigid member 30 changed to 2 mm. The dimension W1 of the first stable region 241 was 0.5 mm.

[Example 5]
The same simulation as in Example 1 was performed with the dimension K1 of the first rigid member 30 changed to 10 mm. The dimension W1 of the first stable area 241 was 4.6 mm.

FIG. 34 shows the dimension W1 calculated in Examples 1-5.

FIG. 35 shows Ws1 calculated based on the dimension W1. Ws1 is a value obtained by dividing the dimension W1 of the first stable region 241 by the dimension K1 of the first rigid member 30. As shown in FIG. Rs1 in FIG. 35 is the value obtained by dividing the curvature radius R1 of the first corner 32 by the dimension K1 of the first rigid member 30. In FIG. For example, in Example 1, W1=1.6 mm, K1=4 mm, and R1=0.5 mm, so Ws1=0.4 and Rs1=0.125.

FIG. 36 is a graph showing the relationship between Rs1 and Ws1. As shown in FIG. 36, Ws1 is approximated as a linear function of Rs1 below.
Ws1=−1.1148×Rs1+0.532
Therefore, the following relational expression holds between W1 and R1.
W1 = -1.1148 x R1 + 0.532 x K1

10 Wiring board 20 Base material 21 First surface 22 Second surface 23 First overlapping area 24 First peripheral area 241 First stable area 30 First rigid member 31 First side 32 First corner 35 Second rigid member 36 Second second Side 37 Second corner 38 Conductor 40 Support substrate 41 First surface 42 Second surface 50 Conductive layer 51 Wiring 52 Pad 54 Solder 55 Electronic component 60 Protective layer 63 Second overlap region 64 Second peripheral region 641 Second stable region 70 First insulating layer 71 First hole 75 Second insulating layer

Claims (22)

A wiring board on which electronic components are mounted,
a stretchable base material including a first surface and a second surface located on the opposite side of the first surface;
at least one first rigid member overlapping the base material and the electronic component in plan view and having higher rigidity than the base material;
a conductive layer including wiring located on the first surface side of the base material,
The first rigid member has, in plan view, at least two first corners that are chamfered on a side away from the center of the first rigid member, and a first side that extends between the two first corners. with an outer rim containing
The base material includes a first overlapping region that overlaps the first rigid member in plan view, and a first surrounding region that is in contact with the first overlapping region and does not overlap the first rigid member in plan view,
The first peripheral region includes a first stable region that spreads from the center of the first side toward the side away from the center of the first rigid member in a plan view,
The first stable region has a dimension W1 represented by the following formula in the direction in which the first side extends,
W1 = -1.1148 x R1 + 0.532 x K1
R1 is the chamfer dimension of the first corner, K1 is the dimensions of the two first corners and the first side in the direction in which the first side extends,
A wiring substrate, wherein the wiring extends through the first stability region to reach the first overlap region. The wiring board according to claim 1, wherein R1/K1 is 0.020 or more and 0.30 or less. 3. The wiring board according to claim 1, wherein the elastic modulus of said first rigid member is ten times or more the elastic modulus of said base material. 4. The wiring board according to claim 1, wherein said first rigid member is positioned on said second surface side of said base material. 4. The wiring board according to claim 1, wherein said first rigid member is embedded in said base material. a first insulating layer that overlaps the first rigid member in plan view and partially covers the conductive layer;
6. The wiring board according to claim 1, further comprising a first hole overlapping said conductive layer in a plan view and penetrating said first insulating layer. 7. The wiring substrate according to claim 6, wherein said conductive layer includes a pad surrounding said first hole in plan view and connected to said wiring. at least one second rigid member that partially overlaps the base material in plan view;
a conductor provided on the second rigid member and electrically connected to the wiring;
the electronic component electrically connected to the wiring via the conductor;
a protective layer located on the first surface side of the base material, having a lower rigidity than the second rigid member, and covering the second rigid member and the electronic component;
The second rigid member has, in plan view, at least two second corners that are chamfered on the side away from the center of the second rigid member, and a second side that extends between the two second corners. with an outer rim containing
The protective layer includes a second overlapping region that overlaps the second rigid member in plan view, and a second surrounding region that is in contact with the second overlapping region and does not overlap the second rigid member in plan view,
The second peripheral region includes a second stable region that spreads from the central portion of the second side toward the side away from the center of the second rigid member in a plan view,
The second stable region has a dimension W2 represented by the following formula in the direction in which the second side extends,
W2 = -1.1148 x R2 + 0.532 x K2
R2 is the chamfer dimension of the second corner, K2 is the dimension of the two second corners and the second side in the direction in which the second side extends,
8. The wiring board according to any one of claims 1 to 7, wherein said wiring extends through said second stability region to reach said second overlapping region. a stretchable base material including a first surface and a second surface located on the opposite side of the first surface;
a conductive layer including wiring located on the first surface side of the base;
at least one second rigid member that partially overlaps the base material in plan view;
a conductor provided on the second rigid member and electrically connected to the wiring;
an electronic component that overlaps the second rigid member in plan view and is electrically connected to the wiring via the conductor;
a protective layer located on the first surface side of the base material, having a lower rigidity than the second rigid member, and covering the second rigid member and the electronic component;
The second rigid member has, in plan view, at least two second corners that are chamfered on the side away from the center of the second rigid member, and a second side that extends between the two second corners. with an outer rim containing
The protective layer includes a second overlapping region that overlaps the second rigid member in plan view, and a second surrounding region that is in contact with the second overlapping region and does not overlap the second rigid member in plan view,
The second peripheral region includes a second stable region that spreads from the central portion of the second side toward the side away from the center of the second rigid member in a plan view,
The second stable region has a dimension W2 represented by the following formula in the direction in which the second side extends,
W2 = -1.1148 x R2 + 0.532 x K2
R2 is the chamfer radius of the second corner, K2 is the dimension of the two second corners and the second side in the direction in which the second side extends,
A wiring substrate, wherein the wiring extends through the second stability region to reach the second overlap region. 10. The wiring board according to claim 9, wherein R2/K2 is 0.020 or more and 0.30 or less. 11. The wiring board according to claim 9, wherein the elastic modulus of said second rigid member is 10 times or more the elastic modulus of said protective layer. a first insulating layer overlapping the second rigid member in plan view and partially covering the conductive layer;
a first hole overlapping the conductive layer in plan view and penetrating the first insulating layer;
12. The wiring board according to claim 9, further comprising a solder positioned in the first hole and connected to the conductive layer and the conductor. 13. The wiring substrate according to claim 12, wherein said conductive layer includes a pad surrounding said first hole in plan view and connected to said wiring. The wiring board according to any one of claims 1 to 13, wherein the base material includes thermoplastic elastomer, silicone rubber, urethane gel, or silicone gel. 15. The wiring board according to any one of claims 1 to 14, comprising a support substrate that supports said wiring. 16. The wiring board according to claim 15, wherein the elastic modulus of said supporting substrate is ten times or more the elastic modulus of said base material. 17. The wiring board according to claim 15, wherein said supporting substrate contains polyethylene naphthalate, polyimide, polycarbonate, acrylic resin, or polyethylene terephthalate. The wiring board according to any one of claims 1 to 17, further comprising a second insulating layer located on the first surface side of the base material and at least partially overlapping the wiring in plan view. 19. The wiring board according to claim 18, wherein said second insulating layer has a larger elastic modulus than said base material. The wiring board according to any one of claims 1 to 19, wherein the wiring includes a plurality of ridges arranged in the length direction of the wiring. A method for manufacturing a wiring board on which electronic components are mounted, comprising:
A stretchable substrate including a first surface and a second surface located on the opposite side of the first surface, overlapping the substrate and the electronic component in plan view, and having higher rigidity than the substrate a stretching step of applying tension to the substrate of a laminate comprising at least one first rigid member to elongate the substrate;
a wiring forming step of providing wiring on the first surface side of the base material stretched by the stretching step;
a shrinking step that removes tension from the substrate;
The first rigid member has, in plan view, at least two first corners that are chamfered on a side away from the center of the first rigid member, and a first side that extends between the two first corners. with an outer rim containing
The base material includes a first overlapping region that overlaps the first rigid member in plan view, and a first surrounding region that is in contact with the first overlapping region and does not overlap the first rigid member in plan view,
The first peripheral region includes a first stable region that spreads from the center of the first side toward the side away from the center of the first rigid member in a plan view,
The first stable region has a dimension W1 represented by the following formula in the direction in which the first side extends,
W1 = -1.1148 x R1 + 0.532 x K1
R1 is the chamfer dimension of the first corner, K1 is the dimensions of the two first corners and the first side in the direction in which the first side extends,
The wiring substrate manufacturing method, wherein the wiring extends through the first stable region to reach the first overlapping region. an elongation step of applying tension to a stretchable substrate comprising a first surface and a second surface located opposite to the first surface to elongate the substrate;
a wiring forming step of providing wiring on the first surface side of the base material stretched by the stretching step;
a shrinking step that removes tension from the substrate;
At least one second rigid member, a conductor provided on the second rigid member and electrically connected to the wiring, and the second rigid member in plan view on the first surface side of the base material an electronic component that overlaps with the conductor and is electrically connected to the wiring via the conductor; a protective layer that has lower rigidity than the second rigid member and covers the second rigid member and the electronic component; is provided,
The second rigid member has, in plan view, at least two second corners that are chamfered on the side away from the center of the second rigid member, and a second side that extends between the two second corners. with an outer rim containing
The protective layer includes a second overlapping region that overlaps the second rigid member in plan view, and a second surrounding region that is in contact with the second overlapping region and does not overlap the second rigid member in plan view,
The second peripheral region includes a second stable region that spreads from the central portion of the second side toward the side away from the center of the second rigid member in a plan view,
The second stable region has a dimension W2 represented by the following formula in the direction in which the second side extends,
W2 = -1.1148 x R2 + 0.532 x K2
R2 is the chamfer dimension of the second corner, K2 is the dimension of the two second corners and the second side in the direction in which the second side extends,
The wiring substrate manufacturing method, wherein the wiring extends through the second stable region to reach the second overlapping region.

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