JP7383972B2 - Wiring board and wiring board manufacturing method - Google Patents

Description

Embodiments of the present disclosure relate to wiring boards. Further, embodiments of the present disclosure relate to a method for manufacturing a wiring board.

In recent years, research has been conducted on electronic devices that have deformability such as stretchability. For example, Patent Document 1 discloses a stretchable 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 provided on a base material that has been stretched in advance, and the base material is relaxed after the circuit is formed. Patent Document 1 is intended to allow a thin film transistor on a base material to operate well in both a stretched state and a relaxed state of the base material.

Japanese Patent Application Publication No. 2007-281406

The conventional wiring board as described above includes not only a portion that is resistant to deformation such as expansion and contraction, but also a portion that is easily damaged due to deformation. For this reason, if a circuit is provided on a base material that has been stretched in advance, problems such as damage to the wiring board are likely to occur.

On the other hand, when mounting the base material of a wiring board on a mounted object, such as a human body or an object, an adhesive layer of an adhesive is provided on the entire surface of the silicone rubber base material, and the adhesive layer is applied to the mounted object. Paste it on your body. If the adhesive layer is attached to an object to be mounted for a long time, the surface to which the wiring board is attached may feel hard and tense when attached to the object to be mounted, such as a human body or an object. In some cases, it was uncomfortable to wear.

Embodiments of the present disclosure aim to provide a wiring board and a method for manufacturing a wiring board that can effectively solve such problems.

One embodiment of the present disclosure is a wiring board having stretchability,
a base material including a first surface and a second surface located on the opposite side of the first surface, and having a first elastic modulus;
Wiring located on the first surface side or the second surface side of the base material;
A bonding surface located on the second surface side of the base material and attached to the second surface side of the base material, and a bonding surface located on the opposite side of this bonding surface, the wiring board being mounted on the mounted object. a mounting adhesive layer that includes a mounting surface that comes into contact with the object to be mounted and has air permeability;
The wiring board, wherein the mounting adhesive layer has a smaller elastic modulus than the first elastic modulus of the base material.

A wiring board according to an embodiment of the present disclosure includes:
A wiring board having stretchability,
a base material including a first surface and a second surface located on the opposite side of the first surface, and having a first elastic modulus;
Wiring located on the first surface side or the second surface side of the base material;
A bonding surface located on the second surface side of the base material and attached to the second surface side of the base material, and a bonding surface located on the opposite side of this bonding surface, the wiring board being mounted on the mounted object. an adhesive layer for mounting that includes a mounting surface that comes into contact with the object to be mounted and has air permeability;
a pasting adhesive layer located between the second surface of the base material and the mounting adhesive layer and containing an adhesive for pasting the mounting adhesive layer to the base material;
In the wiring board, the elastic modulus of the adhesive layer for sticking is smaller than the first elastic modulus of the base material.

In a wiring board according to an embodiment of the present disclosure,
further comprising an additional layer located between the second surface of the base material and the attachment surface of the mounting adhesive layer, and having a first surface and a second surface opposite to the first surface,
The elastic modulus of the additional layer may be smaller than the first elastic modulus of the base material.

In a wiring board according to an embodiment of the present disclosure,
The mounting adhesive layer may contain an acrylic adhesive, a silicone adhesive, a urethane adhesive, or an epoxy adhesive.

In a wiring board according to an embodiment of the present disclosure,
A notch may be formed in the mounting adhesive layer.

In a wiring board according to an embodiment of the present disclosure,
The mounting adhesive layer may have lower hardness or tensile strength than the base material.

In a wiring board according to an embodiment of the present disclosure,
The adhesive layer for pasting may be a silicone adhesive, a modified silicone adhesive, a mixture of a modified silicone adhesive and an epoxy adhesive, a urethane adhesive, an acrylic adhesive, or an epoxy adhesive. It may also include either one.

In a wiring board according to an embodiment of the present disclosure,
A notch may be formed in the adhesive layer for pasting.

In a wiring board according to an embodiment of the present disclosure,
The additional layer may be a layer containing elastomer rubber, silicone rubber, gel, or a porous material.

In a wiring board according to an embodiment of the present disclosure,
The mounting adhesive layer may include a material using nonwoven fabric, urethane, or foam.

In a wiring board according to an embodiment of the present disclosure,
The base material may include silicone rubber.

In a wiring board according to an embodiment of the present disclosure,
The wiring may have a bellows-shaped portion including a plurality of peaks and valleys arranged along an in-plane direction of the first surface of the base material.

In a wiring board according to an embodiment of the present disclosure,
The device may further include a support substrate located between the wiring and the base material, having a third elastic modulus larger than the first elastic modulus, and supporting the wiring.

In a wiring board according to an embodiment of the present disclosure,
located inside the base material, on the first surface side of the base material, or on the second surface side of the base material, and when viewed along the normal direction of the first surface of the base material. The electronic device may further include a reinforcing member that at least partially overlaps the electronic component mounted on the wiring board and has a second elastic modulus larger than the first elastic modulus.

In a wiring board according to an embodiment of the present disclosure,
A portion of the wiring that does not overlap with the reinforcing member when viewed along the normal direction of the first surface includes a plurality of peaks and valleys lined up in the in-plane direction of the first surface of the base material. It may have a bellows-shaped portion including a portion.

In a wiring board according to an embodiment of the present disclosure,
The amplitude of the bellows-shaped portion of the wiring may be 1 μm or more.

In a wiring board according to an embodiment of the present disclosure,
The reinforcing member may include a metal layer.

In a wiring board according to an embodiment of the present disclosure,
The wiring may include a plurality of conductive particles.

In a wiring board according to an embodiment of the present disclosure,
The electronic device may further include an electronic component located on the first surface side of the base material and having an electrode electrically connected to the wiring.

In a wiring board according to an embodiment of the present disclosure,
The resistance value of the wiring in a first state in which no tensile stress along the in-plane direction of the first surface of the base material is applied to the base material is referred to as a first resistance value, and the tensile stress is applied to the base material. When the resistance value of the wiring in a second state where the base material is elongated by 30% in the in-plane direction of the first surface compared to the first state is referred to as a second resistance value, , the ratio of the absolute value of the difference between the first resistance value and the second resistance value may be 20% or less.

A method for manufacturing a wiring board according to an embodiment of the present disclosure includes:
A method for manufacturing a stretchable wiring board, the method comprising:
A first step of elongating the base material by applying tensile stress to the base material, which includes a first surface and a second surface located on the opposite side of the first surface, and has a first elastic modulus;
a second step of providing wiring on the first surface side or the second surface side of the base material in an expanded state;
a third step of removing the tensile stress from the base material;
On the second surface side of the base material, an attachment surface that is attached to the second surface side of the base material, and an attachment surface located on the opposite side of this attachment surface when the wiring board is mounted on a mounted object. a fourth step of providing a mounting adhesive layer including a mounting surface in contact with the mounted object;
In the method for manufacturing a wiring board, the elastic modulus of the mounting adhesive layer is smaller than the first elastic modulus of the base material.

In a method for manufacturing a wiring board according to an embodiment of the present disclosure,
In the fourth step, a pasting adhesive layer containing an adhesive is provided between the second surface of the base material and the mounting adhesive layer, and the pasting adhesive layer is attached to the base material through the pasting adhesive layer. a pasting step of pasting the mounting adhesive layer,
The elastic modulus of the adhesive layer for sticking may be smaller than the first elastic modulus of the base material.

In a method for manufacturing a wiring board according to an embodiment of the present disclosure,
forming an additional layer located between the second surface of the base material and the attachment surface of the mounting adhesive layer and having a first surface and a second surface opposite to the first surface; With further processes,
The elastic modulus of the additional layer may be smaller than the first elastic modulus of the base material.

In a method for manufacturing a wiring board according to an embodiment of the present disclosure,
The wiring may have a bellows-shaped portion including a plurality of peaks and valleys arranged along an in-plane direction of the first surface of the base material.

According to the embodiments of the present disclosure, it is possible to improve the comfort of wearing the mounting target and to suppress the occurrence of defects in the wiring board due to expansion and contraction of the base material.

FIG. 1 is a cross-sectional view showing a wiring board according to an embodiment. FIG. 1 is a cross-sectional view showing a wiring board according to an embodiment. FIG. 1 is a plan view showing a wiring board according to an embodiment. 2B is a cross-sectional view showing a case where the wiring board of FIG. 2B is cut along line BB. FIG. FIG. 7 is a cross-sectional view showing a wiring board according to a modified example. 2A is an enlarged cross-sectional view showing an example of wiring and peripheral components of the wiring board shown in FIG. 2A. FIG. 2A is an enlarged cross-sectional view showing another example of the wiring of the wiring board shown in FIG. 2A and components around it. FIG. 2A is an enlarged cross-sectional view showing another example of the wiring of the wiring board shown in FIG. 2A and components around it. FIG. 2A is an enlarged cross-sectional view showing another example of the wiring of the wiring board shown in FIG. 2A and components around it. FIG. FIG. 3 is a diagram for explaining a method for manufacturing a wiring board. FIG. 3 is a diagram for explaining a method for manufacturing a wiring board. FIG. 7 is a cross-sectional view showing a wiring board according to a modified example. FIG. 7 is a cross-sectional view showing a wiring board according to a modified example. FIG. 7 is a cross-sectional view showing a wiring board according to a modified example. FIG. 7 is a cross-sectional view showing a wiring board according to a first modification. FIG. 13 is an enlarged cross-sectional view showing an example of wiring and peripheral components of the wiring board shown in FIG. 12; FIG. 3 is a diagram for explaining a method for manufacturing a wiring board. FIG. 3 is a diagram for explaining a method for manufacturing a wiring board. FIG. 7 is a cross-sectional view showing a wiring board according to a second modification. FIG. 16 is an enlarged cross-sectional view showing an example of wiring and peripheral components of the wiring board shown in FIG. 15; 16 is a diagram for explaining a method of manufacturing the wiring board shown in FIG. 15. FIG. FIG. 7 is a cross-sectional view showing another example of the wiring board according to the third modification. FIG. 7 is a cross-sectional view showing another example of the wiring board according to the third modification. FIG. 7 is a cross-sectional view showing an electronic component according to a fourth modification. It is a top view which shows an example of the electronic component based on the 4th modification. It is a top view which shows an example of the electronic component based on the 4th modification. FIG. 7 is a cross-sectional view showing a wiring board according to a fifth modification.

Hereinafter, a configuration of a wiring board and a method for manufacturing the same according to an embodiment of the present disclosure will be described in detail with reference to the drawings. Note that the embodiments shown below are examples of the embodiments of the present disclosure, and the present disclosure is not to be interpreted as being limited to these embodiments. Further, in this specification, terms such as "substrate," "base material," "sheet," and "film" are not distinguished from each other based only on the difference in name. For example, the term "base material" is a concept that also includes members that can be called substrates, sheets, and films. Furthermore, terms such as "parallel" and "orthogonal" and values of length and angle used in this specification that specify shapes, geometric conditions, and their degrees are bound by strict meanings. The definition shall be interpreted to include the extent to which similar functions can be expected. In addition, in the drawings referred to in this embodiment, the same parts or parts having similar functions are denoted by the same or similar symbols, and repeated description thereof may be omitted. In addition, the dimensional ratios in the drawings may differ from the actual ratios for convenience of explanation, or a part of the structure may be omitted from the drawings.

An embodiment of the present disclosure will be described below with reference to FIGS. 1 to 11.

(wiring board)
First, the wiring board 10 according to the present embodiment will be explained. 1, FIG. 2A, and FIG. 2B are a cross-sectional view and a plan view showing the wiring board 10, respectively. The cross-sectional view shown in FIG. 2A is a diagram when the wiring board 10 of FIG. 2B is cut along line AA.

The wiring board 10 shown in FIG. 2A includes a base material 20, a reinforcing member 31, a support substrate 40, an electronic component 51, wiring 52, an adhesive layer X for mounting, and an adhesive layer Y for pasting. Each component of the wiring board 10 will be explained below. Note that, as shown in FIG. 1, the reinforcing member 31 and the electronic component 51 may not be included in the wiring board 10.

〔Base material〕
The base material 20 is a member configured to have elasticity. The base material 20 includes a first surface 21 located on the electronic component 51 and wiring 52 side, and a second surface 22 located on the opposite side of the first surface 21. The thickness of the base material 20 is, for example, 10 mm or less, and more preferably 1 mm or less. By reducing the thickness of the base material 20, the force required for expansion and contraction of the base material 20 can be reduced. Furthermore, by reducing the thickness of the base material 20, the overall thickness of the product using the wiring board 10 can be reduced. Thereby, for example, when a product using the wiring board 10 is a sensor attached to a part of the body such as a person's arm, the feeling of wearing the product can be reduced. The thickness of the base material 20 may be 10 μm or more.

An example of a parameter representing the elasticity of the base material 20 is the elastic modulus of the base material 20. The elastic modulus of the base material 20 is, for example, 10 MPa or less, more preferably 1 MPa or less. By using the base material 20 having such an elastic modulus, the entire wiring board 10 can be made elastic. In the following description, the elastic modulus of the base material 20 is also referred to as a first elastic modulus. The first elastic modulus of the base material 20 may be 1 kPa or more.

As a method for calculating the first elastic modulus of the base material 20, a method can be adopted in which a sample of the base material 20 is used and a tensile test is performed in accordance with JIS K6251. Alternatively, a method may be adopted in which the elastic modulus of the sample of the base material 20 is measured by a nanoindentation method in accordance with ISO14577. As a measuring device used in the nanoindentation method, a nanoindenter can be used. Possible methods for preparing a sample of the base material 20 include a method of taking out a part of the base material 20 as a sample from the wiring board 10, and a method of taking out a part of the base material 20 as a sample before forming the wiring board 10. It will be done. In addition, as a method of calculating the first elastic modulus of the base material 20, the material constituting the base material 20 is analyzed, and the first elastic modulus of the base material 20 is calculated based on an existing database of materials. It is also possible to adopt this method. Note that the elastic modulus in this application is an elastic modulus in an environment of 25°C.

Another example of the parameter representing the elasticity of the base material 20 is the bending rigidity of the base material 20. Bending rigidity is the product of the moment of inertia of the target member and the elastic modulus of the material constituting the target member, and the unit is N·m ² or Pa·m ⁴ . The 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 that overlaps with the wiring 52 by a plane perpendicular to the direction of expansion and contraction of the wiring board 10. In the following description, the bending rigidity of the base material 20 is also referred to as first bending rigidity.

Examples of materials constituting the base material 20 include thermoplastic elastomer, thermosetting elastomer, silicone rubber, urethane gel, silicone gel, and the like. Further, as the material of the base material 20, for example, cloth such as woven fabric, knitted fabric, or nonwoven fabric can also be used. Examples of thermoplastic elastomers include polyurethane elastomers, styrene thermoplastic elastomers, olefin thermoplastic elastomers, PVC thermoplastic elastomers, ester thermoplastic elastomers, amide thermoplastic elastomers, 1,2-BR thermoplastic elastomers, Fluorine-based thermoplastic elastomer, silicone rubber, urethane rubber, fluororubber, polybutadiene, polyisobutylene, polystyrene-butadiene, polychloroprene, etc. can be used. Considering mechanical strength and abrasion resistance, it is preferable to use a urethane-based elastomer, which is a material using urethane. Furthermore, silicone rubber has excellent heat resistance, chemical resistance, and flame retardancy, and is therefore preferable as a material for the base material 20.

[Reinforcement member]
In this embodiment, an example will be described in which a reinforcing member 31 is provided on the wiring board 10 in order to control the expansion and contraction of the base material 20. However, instead of the reinforcing member 31 applied in this embodiment, other members or structures for controlling the expansion and contraction of the base material 20 may be applied to the wiring board 10. Some members may be omitted.
As described above, the reinforcing member 31 is a mechanism provided on the wiring board 10 in order to control and alleviate the deformation of the base material 20 by reinforcing the base material 20. For example, a portion of the wiring 52 located around the electronic component 51 is likely to be subjected to large stress during expansion and contraction, and is also likely to be caught under the electronic component 51, increasing the risk of damage. Here, according to the present embodiment, by providing the reinforcing member 30 on the base material 20, it becomes possible to control, particularly alleviate, the deformation of the portion of the base material 20 around the electronic component 51. As a result, it is possible to suppress the occurrence of large stress locally in the wiring 52 and the wiring 52 from being caught under the electronic component 51, and it is possible to suppress disconnection between the wiring 52 and the electronic component 51. . In the example shown in FIG. 2A, the reinforcing member 31 is provided inside the base material 20. Note that the reinforcing member 31 may be located on the second surface 22 side of the base material 20 or may be located on the first surface 21 side of the base material 20.

The reinforcing member 31 has a larger elastic modulus than the first elastic modulus of the base material 20. The elastic modulus of the reinforcing member 31 is, for example, 0.1 GPa or more, preferably 10 GPa or more. The elastic modulus of the reinforcing member 31 may be 100 times or more, or 1000 times or more, the first elastic modulus of the base material 20. By providing such a reinforcing member 31 on the base material 20, it is possible to suppress expansion and contraction of the portion of the base material 20 that overlaps with the reinforcing member 31. Thereby, the base material 20 can be divided into a portion where expansion and contraction is likely to occur and a portion where expansion and contraction is less likely to occur. If the elastic modulus of the reinforcing member 30 is too low, it may be difficult to control expansion and contraction. Furthermore, if the elastic modulus of the reinforcing member 30 is too high, structural damage such as cracks or cracks may occur in the reinforcing member 30 when the base material 20 expands and contracts. In the following description, the elastic modulus of the reinforcing member 31 is also referred to as a second elastic modulus. The second elastic modulus of the reinforcing member 31 may be 500 GPa or less. Further, the second elastic modulus of the reinforcing member 31 may be 1.1 times or more and 1,000,000 times or less, more preferably 100,000 times or less, than the first elastic modulus of the base material 20. Note that "overlapping" means that two components overlap when viewed along the normal direction of the first surface 21 of the base material 20.

A method for calculating the second elastic modulus of the reinforcing member 31 is determined as appropriate depending on the form of the reinforcing member 31. For example, the method for calculating the second elastic modulus of the reinforcing member 31 may be the same as or different from the method for calculating the elastic modulus of the base material 20 described above. The same applies to the elastic modulus of the support substrate 40, which will be described later. For example, as a method for calculating the elastic modulus of the reinforcing member 31 or the supporting substrate 40, a method can be adopted in which a sample of the reinforcing member 31 or the supporting substrate 40 is used and a tensile test is performed in accordance with ASTM D882. .

Further, the reinforcing member 31 has a bending rigidity greater than the first bending rigidity of the base material 20. The bending rigidity of the reinforcing member 31 may be 1.1 times or more, more preferably 2 times or more, and more preferably 10 times or more the first bending rigidity of the base material 20. In the following description, the bending rigidity of the reinforcing member 31 is also referred to as second bending rigidity.

Examples of the material constituting the reinforcing member 31 include a metal layer containing a metal material, a general thermoplastic elastomer, an acrylic type, a urethane type, an epoxy type, a polyester type, an epoxy type, a vinyl ether type, a polyene/thiol type, Examples include silicone-based oligomers and polymers. Examples of metal materials include copper, aluminum, stainless steel, solder materials, and the like. The thickness of the reinforcing member 31 is, for example, 10 μm or more, but is not particularly limited. Among the above-mentioned materials, the metal layer is more preferable because it has a high elastic modulus and can be microfabricated by etching or the like.
Further, as examples of materials for the reinforcing member 31, PET film, PEN film, etc. can be used, and for example, polyethylene naphthalate, polyimide, polycarbonate, acrylic resin, polyethylene terephthalate, etc. can be used.

When using an oligomer or a polymer as the material constituting the reinforcing member 31, the reinforcing member 31 may have transparency. Further, the reinforcing member 31 may have a light blocking property, for example, a property of blocking ultraviolet rays. For example, the reinforcing member 31 may be black. Further, the color of the reinforcing member 31 and the color of the base material 20 may be the same.

FIG. 3 is a cross-sectional view showing the wiring board 10 of FIG. 2B taken along line BB. Note that since FIG. 2B is a plan view showing the wiring board 10 viewed from the first surface 21 side of the base material 20, the reinforcing member 31 located on the second surface 22 side is represented by a dotted line.

[Support board]
The support substrate 40 is a plate-shaped member configured to have lower elasticity than the base material 20. The support substrate 40 includes a second surface 42 located on the base material 20 side and a first surface 41 located on the opposite side of the second surface 42. In the example shown in FIGS. 1 and 2A, the support substrate 40 supports an electronic component 51 and wiring 52 on its first surface 41 side. Further, the support substrate 40 is bonded to the first surface of the base material 20 on the second surface 42 side thereof. For example, an adhesive layer 60 containing an adhesive may be provided between the base material 20 and the support substrate 40. As the material constituting the adhesive layer 60, for example, acrylic adhesive, silicone adhesive, etc. can be used. The thickness of the adhesive layer 60 is, for example, 5 μm or more and 200 μm or less. Further, as shown in FIG. 9, the second surface 42 of the support substrate 40 may be bonded to the first surface 21 of the base material 20 by room temperature bonding or molecular bonding. In this case, an adhesive layer may not be provided between the base material 20 and the support substrate 40. Further, a primer layer may be provided on one or both of the first surface 21 of the base material 20 and the second surface 42 of the support substrate 40 to improve adhesiveness of room-temperature bonding and molecular adhesion. When the second surface 42 of the support substrate 40 is bonded to the first surface 21 of the base material 20 by room-temperature bonding or molecular bonding, the reinforcing member 31 is bonded to the first surface 21 of the base material 20 or It is preferable that it is embedded in the base material 20 so as not to be exposed to the second surface 22.

As will be described later, when the tensile stress is removed from the base material 20 bonded to the support substrate 40 and the base material 20 contracts, a bellows-shaped portion is formed on the support substrate 40. The characteristics and dimensions of the support substrate 40 are set so that such a bellows-shaped portion can be easily formed. For example, the support substrate 40 has a larger elastic modulus than the first elastic modulus of the base material 20. In the following description, the elastic modulus of the support substrate 40 is also referred to as a third elastic modulus.

The third elastic modulus of the support substrate 40 is, for example, 100 MPa or more, and more preferably 1 GPa or more. The third elastic modulus of the support substrate 40 may be 100 times or more, 1000 times or more and 100,000 times or less, 1000 times or more and 50,000 times or less than the first elastic modulus of the base material 20. There may be. Note that if the elastic modulus of the support substrate 40 is too low, the support substrate 40 is likely to deform during the process of forming the reinforcing member 30, and as a result, alignment of the reinforcing member 30 with respect to the electronic component 51 and the wiring 52 becomes difficult. Furthermore, if the elastic modulus of the support substrate 40 is too high, it will be difficult to restore the base material 20 when relaxed, and the base material 20 will be more likely to crack or bend. Further, the thickness of the support substrate 40 is, for example, 10 μm or less, more preferably 5 μm or less. By increasing the elastic modulus of the support substrate 40 or reducing the thickness of the support substrate 40, a bellows-shaped portion is more likely to be formed on the support substrate 40 as the base material 20 contracts. As the material constituting the support substrate 40, for example, polyethylene naphthalate, polyimide, polycarbonate, acrylic resin, polyethylene terephthalate, etc. can be used. Among them, polyethylene naphthalate or polyimide, which has good durability and heat resistance, are preferred. It can be preferably used.

The third elastic modulus of the support substrate 40 may be 100 times or less than the first elastic modulus of the base material 20. The method for calculating the third elastic modulus of the support substrate 40 is the same as that for the base material 20. Further, the thickness of the support substrate 40 may be 500 nm or more.
[Adhesive layer for mounting]
The mounting adhesive layer X is located on the second surface 22 side of the base material 20, for example, as shown in FIGS. 1 and 2A. Note that the mounting adhesive layer X may be located on the first surface 21 side of the base material 20, for example, as shown in FIG.
This mounting adhesive layer It includes a mounting surface X2 that comes into contact with the object to be mounted when the mounting surface is mounted. This mounting adhesive layer X has air permeability. Note that the mounting adhesive layer X may include, for example, an acrylic adhesive, a silicone adhesive, a urethane adhesive, or an epoxy adhesive. In particular, when implementing it on a living body such as the human body, it is desirable to consider safety to the human body and living organisms, and it is desirable to pass tests conducted in accordance with JIS T 0993-1 or ISO 10993 "Biological evaluation of medical devices". It is more preferable that you do so.
Further, this mounting adhesive layer X may include an additional base material. In this case, the materials used for the additional base material include urethane, nonwoven fabric, polyester, polyethylene, moisture permeable film, polyurethane, rayon nonwoven fabric, polyester nonwoven fabric, polyurethane nonwoven fabric, rayon woven fabric, acetate woven fabric, cellulose nonwoven fabric, cotton fabric, Examples include polyester knitted fabrics. Among these, when the object to be mounted is a human body, from the viewpoint of comfort during mounting, it is preferable that the base material has high elasticity, and urethane and nonwoven fabric are preferable. In this case, the additional base material is located on the attachment surface X1 side, and the adhesive is located on the mounting surface X2 side.
Note that the above-mentioned mounted object is, for example, a living body such as a human body or an animal, but may be an object other than a living body such as a human body.

The elastic modulus of this mounting adhesive layer X is set to be smaller than, for example, the first elastic modulus of the base material 20 described above. In particular, the mounting adhesive layer is set to have lower hardness or tensile strength than the base material 20.
In this case, for example, the mounting adhesive layer X may have a notch formed therein. The mounting adhesive layer X may have any size or shape of the cut as long as it has a lower tensile strength than the base material 20. The mounting adhesive layer X may be formed with a through hole that penetrates in the depth direction, or may not be penetrated but partially cut in the depth direction. Further, the mounting adhesive layer X may penetrate diagonally or adjacently in the horizontal direction, or may not penetrate but may have a partial cut. Alternatively, it may have a shape with a cavity provided inside. When it is penetrated, air permeability is improved when it is mounted on an object to be mounted. When a partial cut or a cavity is provided inside, the contact area with the mounted object is large, resulting in high adhesion.

In this way, by providing a layer that is softer than the base material 20 as the mounting adhesive layer X on the side to be applied to the mounted object (skin), the wearing comfort is improved and discomfort when the wiring board 10 is applied is eliminated. can.
The above-mentioned "comfort to wear" means that when the wiring board 10 is mounted on the mounted object, there is no feeling of tension when the mounted object moves, that is, it is soft, and the tensile strength is It should be small, and it should not hurt when pressed from above, that is, it should have few irregularities, be soft and absorbent even when there are irregularities, and not get stuffy, that is, be breathable, moisture permeable, and dry quickly. is

[Adhesive layer for pasting]
The adhesive layer Y for attachment is located between the second surface 22 of the base material 20 and the attachment surface X1 of the adhesive layer X for mounting, for example, as shown in FIGS. 1 and 2A. Note that when the mounting adhesive layer X is located on the first surface 21 side of the base material 20, for example, as shown in FIG. It may be positioned between the adhesive layer X for mounting and the attachment surface X1.

Then, as shown in FIGS. 1 and 2A, for example, this adhesive layer Y for pasting is attached to a first adhesive surface Y1 that is in contact with the second surface 22 of the base material 20, and to the opposite side of this first adhesive surface Y1. It includes a second adhesive surface Y2 located therein and in contact with the attachment surface X1 of the mounting adhesive layer X.

This adhesive layer Y for pasting includes an adhesive for pasting the adhesive layer X for mounting on the base material 20. This adhesive layer Y for pasting is, for example, a silicone adhesive, a modified silicone adhesive, a mixed adhesive of a modified silicone adhesive and an epoxy adhesive, a urethane adhesive, an acrylic adhesive, an epoxy adhesive, etc. It may also contain any adhesive. The curing type may be any curing type, such as a moisture curing type, a thermosetting type, a UV curing type, a two-component mixture curing type, a heat melting type, a pressure sensitive type, or a rewetting type.

In addition, the elastic modulus of this adhesive layer Y for pasting is set to be smaller than the 1st elastic modulus of the base material 20, for example. In this case, the adhesive layer Y for pasting may have a notch formed therein. The size and shape of the cut may be any size and shape as long as the tensile strength is lower than that of the base material. The mounting adhesive layer X may be penetrating in the depth direction, or may not be penetrating but may be partially cut in the depth direction. Further, it may penetrate diagonally or adjacently in the horizontal direction, or it may not penetrate and may be partially cut. Alternatively, it may have a shape with a cavity provided inside. When it is penetrated, air permeability is improved when it is mounted on an object to be mounted. When a partial cut or a cavity is provided inside, the contact area with the base material and mounting adhesive layer is large, resulting in high adhesion.
Moreover, this adhesive layer Y for pasting may include an additional base material. In this case, the materials used for the additional base material include urethane, nonwoven fabric, polyester, polyethylene, moisture permeable film, polyurethane, rayon nonwoven fabric, polyester nonwoven fabric, polyurethane nonwoven fabric, rayon woven fabric, acetate woven fabric, cellulose nonwoven fabric, cotton fabric, Examples include polyester knitted fabrics. Among these, when the object to be mounted is a human body, the base material is preferably one with high elasticity, considering that it will be movable during mounting, and urethane and nonwoven fabric are preferable. In this case, the base material is located on the attachment surface Y2 side, and the adhesive is located on the mounting surface Y1 side.

In this way, by providing a layer that is softer than the base material 20 as the adhesive layer Y on the side to be applied to the object to be mounted (skin), the wearing comfort is improved and discomfort when the wiring board 10 is applied is eliminated. can.

[Additional layer]
Here, the wiring board 10 may further include an additional layer N, as shown in FIG. 4, for example.

In this case, the additional layer N is, for example, as shown in FIG. It is located between. This additional layer N has a first surface N1 and a second surface N2 opposite to this first surface N1. This additional layer N has breathability. Furthermore, this additional layer N may have water absorption or quick drying properties. Note that this additional layer N is, for example, a layer containing elastomer rubber, silicone rubber, gel, or a porous material. Examples of the layer having a porous material include urethane, polyethylene, rubber, silicone, melamine sponge, acrylic foam, and polyvinyl chloride. The layer having this porous material itself has air permeability in all directions in the vertical direction (depth direction) and in the lateral direction. With this additional layer N, even if the pasting adhesive Y above the additional layer N or the base material 20 itself does not have air permeability, the air permeability in the lateral direction makes it possible to ensure air permeability from the surface to be mounted.

Note that the elastic coefficient of this additional layer N is set to be smaller than, for example, the first elastic coefficient of the base material 20. In this case, the additional layer N may have cuts formed therein. The additional layer N may have any size or shape of the cut as long as it has a lower tensile strength than the base material 20. The additional layer N may be formed with a through hole penetrating in the depth direction, or may be partially cut in the depth direction without penetrating it. Furthermore, the additional layer N may penetrate diagonally or adjacently in the horizontal direction, or may not penetrate and may be partially cut. Alternatively, it may have a shape with a cavity provided inside. When it is penetrated, air permeability is improved when it is mounted on an object to be mounted. When a partial cut or a cavity is provided inside, the contact area with the adhesive adhesive layer and the adhesive layer for mounting is large, resulting in high adhesion.

In this way, by providing a layer that is softer than the base material 20 as the additional layer N on the side to be attached to the mounted object (skin), it becomes easier to follow the movement of the mounted object when it moves, improving the wearing comfort, and Discomfort when pasting the substrate 10 can be eliminated.

Here, the relationship between the elastic modulus of each layer is best such that the elastic modulus of the base material 20≧the elastic modulus of the additional layer N≧the elastic modulus of the adhesive layer Y for pasting≧the elastic modulus of the adhesive layer X for mounting. preferable.
However, the relationship between the elastic modulus of each layer is such that the elastic modulus of the base material 20 ≧ the elastic modulus of the additional layer N = the elastic modulus of the adhesive layer Y for pasting = the elastic modulus of the adhesive layer X for mounting. good.
Note that the mounting adhesive layer Y and the pasting adhesive layer X only need to function as adhesives, and it is also preferable to make the thickness thin. The thickness of the additional layer N may be any thickness as long as it has a tensile strength lower than that of the base material 20, but if it is thick, it can absorb and soften the hardness of the base material (=the stiffness due to the high tensile strength). If the device is thin, the entire device becomes lighter, which reduces the feeling of wearing it.

[Electronic Component] In the example shown in FIG. 2A, the electronic component 51 has at least an electrode connected to the wiring 52. The electronic component 51 may be an active component, a passive component, or a mechanical component.
Examples of the electronic components 51 include transistors, LSIs (Large-Scale Integrations), MEMS (Micro Electro Mechanical Systems), relays, light emitting elements such as LEDs, OLEDs, and LCDs, sensors, sounding components such as buzzers, and vibrations that generate vibrations. Examples include parts, cooling heat generating parts such as Peltier elements and heating wires that control cooling heat generation, resistors, capacitors, inductors, piezoelectric elements, switches, connectors, etc. Among the above-mentioned examples of electronic components 51, sensors are preferably used. Examples of the sensor include a temperature sensor, pressure sensor, optical sensor, photoelectric sensor, proximity sensor, shear force sensor, biological sensor, laser sensor, microwave sensor, humidity sensor, strain sensor, gyro sensor, acceleration sensor, displacement sensor, Examples include magnetic sensors, gas sensors, GPS sensors, ultrasonic sensors, odor sensors, brain wave sensors, current sensors, vibration sensors, pulse wave sensors, electrocardiographic sensors, and light intensity sensors. Among these sensors, biological sensors are particularly preferred. A biosensor can measure biometric information such as heartbeat, pulse, electrocardiogram, blood pressure, body temperature, and blood oxygen concentration.

〔wiring〕
The wiring 52 is a conductive member connected to the electrode of the electronic component 51. For example, as shown in FIG. 2B, one end and the other end of the wiring 52 are connected to electrodes of two electronic components 51, respectively. As shown in FIG. 2B, a plurality of wiring lines 52 may be provided between two electronic components 51.
In addition, although this wiring 52 is located on the first surface 21 side of the base material 20 in the examples of FIGS. 1 and 2A, it may be located on the second surface 22 side of the base material 20.

As will be described later, when the tensile stress is removed from the base material 20 bonded to the support substrate 40 and the base material 20 contracts, the wiring 52 deforms into a bellows shape. In consideration of this point, the wiring 52 preferably has a structure that is resistant to deformation. For example, the wiring 52 includes a base material and a plurality of conductive particles dispersed within the base material. In this case, by using a deformable material such as resin as the base material, the wiring 52 can also be deformed according to the expansion and contraction of the base material 20. Further, the conductivity of the wiring 52 can be maintained by setting the distribution and shape of the conductive particles so that contact between the plurality of conductive particles is maintained even when deformation occurs. .

As the material constituting the base material of the wiring 52, for example, general thermoplastic elastomers and thermosetting elastomers can be used, such as styrene elastomers, acrylic elastomers, olefin elastomers, urethane elastomers, and silicone. Rubber, urethane rubber, fluororubber, nitrile rubber, polybutadiene, polychloroprene, etc. can be used. Among these, resins and rubbers containing urethane-based and silicone-based structures are preferably used in view of their elasticity and durability. Further, as the material constituting the conductive particles of the wiring 52, particles of silver, copper, gold, nickel, palladium, platinum, carbon, etc. can be used, for example. Among them, silver particles are preferably used from the viewpoint of cost and conductivity.

Note that the wiring 52 is required to follow the expansion and contraction of the base material 20 by utilizing the cancellation and formation of the bellows-shaped portion 57. Considering this point, the material for the wiring 52 is not only one that itself has deformability and stretchability as described above, but also a material that does not itself have deformability and stretchability. Adoptable.
Examples of materials that do not have elasticity per se that can be used for the wiring 52 include metals such as gold, silver, copper, aluminum, platinum, and chromium, and alloys containing these metals. When the material of the wiring 52 itself does not have elasticity, a metal film can be used as the wiring 52.

The thickness of the wiring 52 may be any thickness that can withstand expansion and contraction of the base material 20, and is appropriately selected depending on the material of the wiring 52 and the like. For example, when the material of the wiring 52 does not have stretchability, the thickness of the wiring 52 can be within the range of 25 nm or more and 50 μm or less, preferably within the range of 50 nm or more and 10 μm or less, and 100 nm or more and 5 μm or less. It is more preferable that it is within the following range.

Further, when the material of the wiring 52 has elasticity, the thickness of the wiring 52 can be within the range of 5 μm or more and 60 μm or less, preferably within the range of 10 μm or more and 50 μm or less, and preferably 20 μm or more and 40 μm or less. More preferably, it is within the range. The width of the wiring 52 is, for example, 50 μm or more and 10 mm or less.

Further, an insulating film is provided on the base material 20 or on the support substrate 40 (described later) and on the wiring 52 provided on the base material 20 or the support substrate 40, to integrally cover the base material 20 or the support substrate 40 and the wiring 52. may be provided. However, the insulating film is not provided on the connection portion of the wiring 52 with the electronic component 51. Such an insulating film can be constructed by heating and curing a thermosetting insulating resin or the like. Alternatively, the insulating film may be made of a UV-cured resin using ultraviolet light, or a solvent-dried resin obtained by applying a solution containing the resin and then volatilizing the solvent in the solution by heat drying. The thickness of the insulating film may be, for example, 10 μm or more and 500 μm or less. Further, the insulating film may be formed by screen printing or the like. Further, the connecting portion 51a may be made of, for example, a conductive adhesive, a solder material, or a terminal integrated with the electronic component 51.

The method for forming the wiring 52 is appropriately selected depending on the material and the like. For example, a method may be used in which a metal film is formed on the base material 20 or a support substrate 40 described later by a vapor deposition method, a sputtering method, a plating method, particularly a Cu plating method, etc., and then the metal film is patterned by a photolithography method. Alternatively, a method may be used in which a metal foil is adhesively laminated on the base material 20 or a support substrate 40 to be described later, and then the metal film is patterned by photolithography. In addition, when the material of the wiring 52 itself has stretchability, for example, a conductive composition containing the above conductive particles and an elastomer is printed on the base material 20 or the support substrate 40 in a pattern by a general printing method. One example is printing. Among these methods, the printing method can be preferably used because it has good material efficiency and can be manufactured at low cost.

[Positional relationship of reinforcing members]
Next, the reinforcing member 31 will be explained based on its positional relationship with the electronic component 51 and the wiring 52.

As shown in FIGS. 2A and 2B, the reinforcing member 31 is arranged so as to at least partially overlap the electronic component 51 when viewed along the normal direction of the first surface 21 of the base material 20. Preferably, the reinforcing member 31 overlaps the electronic component 51 over the entire area of the electronic component 51 when viewed along the normal direction of the first surface 21 of the base material 20 . Therefore, the portion of the base material 20 that overlaps with the electronic component 51, that is, the portion that overlaps with the reinforcing member 31, is less likely to deform than the portion of the base material 20 that does not overlap with the reinforcing member 31. This prevents deformation from occurring in the portion of the base material 20 that overlaps with the electronic component 51 when a force such as tensile stress is applied to the base material 20 or when a force such as tensile stress is removed from the base material 20. can be suppressed. By this, it is possible to suppress stress caused by the deformation of the base material 20 from being applied to the electronic component 51, and it is possible to suppress the electronic component 51 from being deformed or damaged. Furthermore, it is possible to prevent the electrical joint between the electronic component 51 and the wiring 52 from being damaged.

Note that although FIG. 2A shows an example in which the reinforcing member 31 is located inside the base material 20, the position of the reinforcing member 31 is arbitrary. That is, as described above, the reinforcing member 31 may be located on the first surface 21 side of the base material 20, on the second surface 22 side of the base material 20, or inside the base material 20.
Moreover, in the above-mentioned embodiment, the reinforcing member 31 showed the example embedded in the base material 20 so that it may not be exposed to the 1st surface 21 or the 2nd surface 22 of the base material 20. However, the invention is not limited to this, and for example, the reinforcing member 31 may be embedded in the base material 20 so as to be exposed on the first surface 21 of the base material 20. Further, the reinforcing member 31 may be embedded in the base material 20 so as to be exposed on the second surface 22 of the base material 20. Further, the reinforcing member 31 may be embedded in the adhesive layer 60.
Note that the plurality of reinforcing members 31 are provided corresponding to each of the plurality of electronic components 51, for example, as shown in FIG. 2B. An electronic component and a reinforcing member may correspond one-to-one, or a plurality of electronic components and one reinforcing member may correspond.
In particular, the plurality of reinforcing members 31 are attached to the plurality of electronic components 51 mounted on the wiring board 10 when viewed along the normal direction of the first surface 21 of the base material 20, for example, as shown in FIG. 2B. At least partially they correspond to each other and overlap.

[Wiring structure]
Next, the cross-sectional structure of the wiring 52 will be described in detail with reference to FIG. 5A. FIG. 5A is an enlarged cross-sectional view showing an example of the wiring 52 and peripheral components of the wiring board 10 shown in FIG. 2A.

As shown in FIGS. 2A to 3, the entire wiring 52 or most of the wiring 52 is arranged so as not to overlap the reinforcing member 31. Therefore, when the base material 20 undergoes deformation such as shrinkage, the wiring 52 is likely to deform along with the deformation of the base material 20. For example, when the base material 20 is relaxed after the wiring 52 is provided on the stretched base material 20, as shown in FIG. 57 occurs.

The bellows-shaped portion 57 includes peaks and valleys in the normal direction of the first surface 21 of the base material 20 . In FIG. 5A, reference numeral 53 represents a peak appearing on the front surface of the wiring 52, and reference numeral 54 represents a peak appearing on the back surface of the wiring 52. Further, reference numeral 55 represents a valley appearing on the front surface of the wiring 52, and reference numeral 56 represents a valley appearing on the back surface of the wiring 52. The front surface is the surface of the wiring 52 located on the side far from the base material 20, and the back surface is the surface of the wiring 52 located on the side close to the base material 20. Further, in FIG. 5A, symbols 26 and 27 represent peaks and valleys appearing on the first surface 21 of the base material 20. By deforming the base material 20 so that the peaks 26 and troughs 27 appear on the first surface 21, the wiring 52 is deformed into a bellows shape and has a bellows-shaped portion 57. The peaks 26 on the first surface 21 of the base material 20 correspond to the peaks 53 and 54 of the bellows-shaped portion 57 of the wiring 52, and the valleys 27 on the first surface 21 of the base material 20 correspond to the bellows-shaped portion 57 of the wiring 52. This corresponds to the troughs 55 and 56 of the portion 57.

The peaks 53 and 54 and the valleys 55 and 56 appear repeatedly along the in-plane direction of the first surface 21 of the base material 20. The period F in which the peaks 53, 54 and the valleys 55, 56 repeatedly appear is, for example, 10 μm or more and 100 mm or less. Note that although FIG. 5A shows an example in which the plurality of peaks and valleys of the bellows-shaped portion 57 are arranged at a constant period, the present invention is not limited to this. Although not shown, the plurality of peaks and valleys of the bellows-shaped portion 57 may be arranged irregularly along the in-plane direction of the first surface 21. For example, the distance between two adjacent peaks in the in-plane direction of the first surface 21 may not be constant.

In FIG. 5A, the symbol S1 represents the amplitude of the bellows-shaped portion 57 on the surface of the wiring 52. In FIG. The amplitude S1 is, for example, 1 μm or more, and more preferably 10 μm or more. By setting the amplitude S1 to 10 μm or more, the wiring 52 is easily deformed following the expansion of the base material 20. Further, the amplitude S1 may be, for example, 500 μm or less.

The amplitude S1 is determined by, for example, measuring the distance in the normal direction of the first surface 21 between the adjacent peaks 53 and troughs 55 over a certain range in the length direction of the wiring 52, and calculating the average of the distances. It is calculated by asking. The "certain range in the length direction of the wiring 52" is, for example, 10 mm. As a measuring device for measuring the distance between the adjacent peaks 53 and troughs 55, a non-contact measuring device such as a laser microscope may be used, or a contact measuring device may be used. . Alternatively, the distance between adjacent peaks 53 and valleys 55 may be measured based on an image such as a cross-sectional photograph. The same applies to the calculation method of amplitudes S2, S3, and S4, which will be described later.

In FIG. 5A, the symbol S2 represents the amplitude of the bellows-shaped portion 57 on the back surface of the wiring 52. In FIG. Like the amplitude S1, the amplitude S2 is, for example, 1 μm or more, and more preferably 10 μm or more. Further, the amplitude S2 may be, for example, 500 μm or less.

As shown in FIG. 5A, a bellows-shaped portion similar to the wiring 52 may be formed on the support substrate 40, the adhesive layer 60, and the first surface 21 of the base material 20. In FIG. 5A, the symbol S3 represents the amplitude of the bellows-shaped portion on the first surface 21 of the base material 20. In FIG. The bellows-shaped portion on the first surface 21 includes a plurality of peaks 26 and troughs 27 . The amplitude S3 is, for example, 1 μm or more, more preferably 10 μm or more. Further, the amplitude S3 may be, for example, 500 μm or less.

FIG. 5B is an enlarged cross-sectional view showing another example of the wiring 52 and peripheral components of the wiring board 10 shown in FIG. 2A. As shown in FIG. 5B, the bellows-shaped portion may not be formed on the first surface 21 of the base material 20.

FIG. 6 is an enlarged cross-sectional view showing another example of the wiring 52 and peripheral components of the wiring board 10 shown in FIG. 2A. As shown in FIG. 6, a bellows-shaped portion may be formed not only on the first surface 21 but also on the second surface 22 of the base material 20. The bellows-shaped portion on the second surface 22 includes a plurality of peaks 28 and troughs 29. In the example shown in FIG. 6, the peaks 28 of the second surface 22 appear at positions overlapping the valleys 27 of the first surface 21, and the valleys 29 of the second surface 22 overlap the peaks 26 of the first surface 21. They appear in overlapping positions. Although not shown, the positions of the peaks 28 and troughs 29 on the second surface 22 of the base material 20 do not need to overlap with the troughs 27 and ridges 26 on the first surface 21. Further, the number or period of the peaks 28 and troughs 29 on the second surface 22 of the base material 20 may be the same as or different from the number or period of the peaks 26 and troughs 27 on the first surface 21. You can. For example, the period of the peaks 28 and troughs 29 on the second surface 22 of the base material 20 may be larger than the period of the peaks 26 and troughs 27 on the first surface 21. In this case, the period of the peaks 28 and troughs 29 on the second surface 22 of the base material 20 may be 1.1 times or more the period of the peaks 26 and troughs 27 on the first surface 21; It may be .2 times or more, 1.5 times or more, or 2.0 times or more. Note that "the period of the peaks 28 and troughs 29 on the second surface 22 of the base material 20 is larger than the period of the peaks 26 and troughs 27 on the first surface 21" means that This concept includes cases in which no peaks or valleys appear on the surface 22.

In FIG. 6, the symbol S4 represents the amplitude of the peaks 28 and troughs 29 appearing on the second surface 22 of the base material 20. The amplitude S4 of the second surface 22 may be the same as the amplitude S1, or may be different. For example, the amplitude S4 of the second surface 22 may be smaller than the amplitude S1. For example, the amplitude S4 of the second surface 22 may be 0.9 times or less, 0.8 times or less, or 0.6 times or less than the amplitude S1. Further, the amplitude S4 of the second surface 22 may be 0.1 times or more, or may be 0.2 times or more the amplitude S1. When the thickness of the base material 20 is small, the ratio of the amplitude S4 of the second surface 22 to the amplitude S1 tends to be large. Note that "the amplitudes of the peaks 28 and troughs 29 of the second surface 22 of the base material 20 are smaller than the amplitudes of the peaks 26 and troughs 27 of the first surface 21" means that This concept includes cases in which no peaks or valleys appear on the surface 22.

Further, although FIG. 6 shows an example in which the positions of the peaks 28 and troughs 29 of the second surface 22 match the positions of the valleys 27 and ridges 26 of the first surface 21, the present invention is not limited to this. Never. As shown in FIG. 7, the positions of the peaks 28 and troughs 29 of the second surface 22 may be shifted from the positions of the troughs 27 and peaks 26 of the first surface 21 by J. The amount of deviation J is, for example, 0.1×F or more, and may be 0.2×F or more.

The advantages of forming the bellows-shaped portion 57 shown in FIGS. 5A, 5B, 6, and 7 on the wiring 52 will be explained. As mentioned above, the base material 20 has an elastic modulus of 10 MPa or less. Therefore, when tensile stress is applied to the wiring board 10, the base material 20 can be expanded by elastic deformation. Here, if the wiring 52 were similarly expanded due to elastic deformation, the total length of the wiring 52 would increase, the cross-sectional area of the wiring 52 would decrease, and the resistance value of the wiring 52 would increase. It is also conceivable that damage such as cracks may occur in the wiring 52 due to elastic deformation of the wiring 52.

In contrast, in this embodiment, the wiring 52 has a bellows-shaped portion 57. Therefore, when the base material 20 expands, the wiring 52 can follow the expansion of the base material 20 by deforming to reduce the undulations of the bellows-shaped portion 57, that is, by eliminating the bellows shape. can. Therefore, it is possible to suppress the total length of the wiring 52 from increasing and the cross-sectional area of the wiring 52 from decreasing due to the expansion of the base material 20. This can suppress an increase in the resistance value of the wiring 52 due to the expansion of the wiring board 10. Further, it is possible to suppress damage such as cracks from occurring in the wiring 52.

(Method for manufacturing wiring board)
Hereinafter, a method for manufacturing the stretchable wiring board 10 will be described with reference to FIGS. 8A(a) to 8(d).

First, a base material preparation step for preparing the base material 20 is performed. In this embodiment, in the base material preparation step, as shown in FIG. 8A(a), a base material 20 in which a reinforcing member 31 is embedded is prepared. Note that the reinforcing member 31 may be provided on the second surface 22 of the base material 20. In this case, for example, a metal layer is first formed over the entire second surface 22 of the base material 20, and then the metal layer is partially removed by etching or the like. Thereby, the reinforcing member 31 including the metal layer can be formed.

Further, a support substrate preparation step for preparing the support substrate 40 is performed. In this embodiment, in the support substrate preparation step, electronic components 51 and wiring 52 are provided on the first surface 41 of the support substrate 40, as shown in FIG. 8A(b). As a method for providing the wiring 52, for example, a method of printing a conductive paste containing a base material and conductive particles on the first surface 41 of the support substrate 40 can be adopted.

Subsequently, a first step is performed in which a tensile stress T is applied to the base material 20 to elongate the base material 20. The elongation rate of the base material 20 is, for example, 10% or more and 200% or less. The first step may be performed with the base material 20 heated, or may be performed at room temperature. When heating the base material 20, the temperature of the base material 20 is, for example, 50°C or higher and 100°C or lower.

Subsequently, a second step is performed in which the electronic component 51 and the wiring 52 are provided on the first surface 21 side of the base material 20 that has been stretched by the tensile stress T. In the second step of the present embodiment, as shown in FIG. 8A(c), a support substrate 40 on which wiring 52 is provided is placed on the first surface 21 of the base material 20 in an expanded state with the reinforcing member 31 provided thereon. are joined from the second surface 42 side of the support substrate 40. At this time, an adhesive layer 60 may be provided between the base material 20 and the support substrate 40.

After that, a third step of removing the tensile stress T from the base material 20 is performed. As a result, as shown by arrow C in FIG. 8A(d), the base material 20 contracts, and the support substrate 40 and wiring 52 bonded to the base material 20 are also deformed. The third elastic modulus of the support substrate 40 is larger than the first elastic modulus of the base material 20. Therefore, the support substrate 40 and the wiring 52 can be deformed as a bellows-shaped portion.

After the third step, a fourth step of providing a mounting adhesive layer X on the second surface 22 side of the base material 20 is performed (FIG. 8A(d)). That is, in this fourth step, a pasting surface X1 is pasted on the second surface 22 side of the base material 20, and a wiring board 10 is pasted on the second surface 22 side of the base material 20, and the wiring board 10 is pasted on the opposite side of this pasting surface X1. A mounting adhesive layer X having air permeability is provided, including a mounting surface X2 that comes into contact with the mounting object when the mounting surface is mounted on the mounting object (not shown). The mounting adhesive layer X can be pasted by forming it on the entire surface using an applicator or screen printing, and then forming cuts using a cutting plotter or laser processing. Further, when penetrating the side surface or forming a cavity inside, it may be formed in the base material 20 using a mold that forms a through hole or cavity. In addition, if an additional base material is included, after forming an adhesive on the additional base material, cut the mounting adhesive layer, which is a combination of the additional base material and adhesive, using a punching, cutting plotter, or laser cutter. There is also a way to form.
In this fourth step, as shown in FIG. 8B, a pasting adhesive layer Y containing an adhesive is provided between the second surface 22 of the base material 20 and the mounting adhesive layer You may make it carry out the pasting process of pasting the adhesive layer X for mounting on the material 20 via the adhesive layer Y for pasting. The configuration in this case corresponds to the wiring board 10 in FIG. 2A.

Further, in this embodiment, reinforcing member 31 is arranged on first surface 21 of base material 20 so as to overlap electronic component 51 . Therefore, it is possible to suppress the portion of the base material 20 that overlaps with the electronic component 51 from expanding in the first step. Therefore, it is possible to suppress shrinkage of the portion of the base material 20 that overlaps with the electronic component 51 in the third step. By this, it is possible to suppress stress caused by the deformation of the base material 20 from being applied to the electronic component 51, and it is possible to suppress the electronic component 51 from being deformed or damaged. Furthermore, it is possible to prevent the electrical joint between the electronic component 51 and the wiring 52 from being damaged. As described above, according to the present embodiment, by controlling the deformation that occurs in the base material 20 according to the position, it is possible to improve the ease of mounting the electronic component 51 and the reliability of the electronic component 51 and the wiring 52. can.

Note that when the base material 20 is stretched, there is a possibility that the reinforcing member 31 is deformed such as warping. Even if the reinforcing member 31 is deformed, the amount of deformation of the reinforcing member 31 is smaller than the amount of deformation that occurs in the portion of the base material 20 that does not overlap with the reinforcing member 31. Therefore, it is possible to prevent the electronic component 51 from being deformed or damaged. Furthermore, it is possible to prevent the electrical joint between the electronic component 51 and the wiring 52 from being damaged.

An example of the effect on the resistance value of the wiring 52 obtained by the bellows-shaped portion 57 of the wiring 52 will be described. Here, the resistance value of the wiring 52 in a first state in which no tensile stress along the in-plane direction of the first surface 21 of the base material 20 is applied to the base material 20 is referred to as a first resistance value. Further, the resistance value of the wiring 52 in a second state where tensile stress is applied to the base material 20 and the base material 20 is elongated by 30% in the in-plane direction of the first surface 21 compared to the first state is determined as the second resistance value. It is called. According to the present embodiment, by forming the bellows-shaped portion 57 in the wiring 52, the ratio of the absolute value of the difference between the first resistance value and the second resistance value to the first resistance value is set to 20% or less. It can be made more preferably 10% or less, and still more preferably 5% or less.

Applications of the wiring board 10 include the healthcare field, medical field, nursing care field, electronics field, sports/fitness field, beauty field, mobility field, livestock/pet field, amusement field, fashion/apparel field, security field, and military field. , distribution field, education field, building materials/furniture/decoration field, environmental energy field, agriculture, forestry and fisheries field, and robot field. For example, a product to be attached to a part of a person's body, such as an arm, is configured using the wiring board 10 according to this embodiment. Since the wiring board 10 can be expanded, for example, by attaching the wiring board 10 to the body in an expanded state, the wiring board 10 can be brought into closer contact with a part of the body. Therefore, a good wearing feeling can be achieved. Further, since it is possible to suppress the resistance value of the wiring 52 from decreasing when the wiring board 10 is expanded, it is possible to realize good electrical characteristics of the wiring board 10. In addition, since the wiring board 10 can be extended, it can be installed or incorporated along not only living bodies such as humans but also curved surfaces and three-dimensional shapes. Examples of these products include vital sensors, masks, hearing aids, toothbrushes, adhesive plasters, compresses, contact lenses, prosthetic hands, prosthetic legs, artificial eyes, catheters, gauze, drug packs, bandages, disposable bioelectrodes, diapers, rehabilitation equipment, and home appliances. Products, displays, signage, personal computers, mobile phones, mice, speakers, sportswear, wristbands, headbands, gloves, swimwear, supporters, balls, gloves, rackets, clubs, bats, fishing rods, relay batons and gymnastics equipment, In addition, grips, physical training equipment, floats, tents, swimsuits, bibs, goal nets, goal tape, beauty masks with liquid penetration, electric stimulation diet products, pocket warmers, artificial nails, tattoos, cars, airplanes, trains, ships, and bicycles. , strollers, drones, wheelchairs, seats, instrument panels, tires, interiors, exteriors, saddles, handles, roads, rails, bridges, tunnels, gas and water pipes, electric wires, tetrapods, ropes, collars, leashes, etc. Harnesses, animal tags, bracelets, belts, game equipment, haptic devices such as controllers, place mats, tickets, dolls, stuffed animals, cheering goods, hats, clothes, glasses, shoes, insoles, socks, stockings, slippers, Innerwear, mufflers, earmuffs, bags, accessories, rings, watches, ties, 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, wireless power antennas, batteries, greenhouses, nets, robot hands, and robot exteriors.

Note that various changes can be made to the embodiments 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 corresponding parts in the above-described embodiment are used for parts that can be configured similarly to the above-described embodiment, Omit duplicate explanations. Furthermore, if it is clear that the effects obtained in the above-described embodiment can also be obtained in the modified example, the explanation thereof may be omitted.

(First modification)
In the above-described embodiment, an example was shown in which the reinforcing member 31 is located inside the base material 20, but the reinforcing member 31 is located inside the base material 20 on the first surface 21 side (for example, It may be provided inside the adhesive layer 60). For example, as shown in FIG. 12, the reinforcing member 31 may be located between the first surface 21 of the base material 20 and the electronic component 51. In the example shown in FIG. 12, the reinforcing member 31 is located on the second surface 42 of the support substrate 40.

FIG. 13 is an enlarged cross-sectional view showing an example of the wiring 52 and peripheral components of the wiring board 10 shown in FIG. 12. Also in this modification, a bellows-shaped portion 57 is formed in a portion of the wiring 52 that does not overlap with the reinforcing member 31, as in the above-described embodiment. Therefore, it is possible to suppress the total length of the wiring 52 from increasing and the cross-sectional area of the wiring 52 from decreasing due to deformation of the base material 20.

14A(a) to (d) are diagrams for explaining a method of manufacturing the stretchable wiring board 10 shown in FIG. 12.

First, as shown in FIG. 14A(a), a base material preparation step for preparing the base material 20 is performed. Subsequently, as shown in FIG. 14A(b), a support substrate preparation step for preparing the support substrate 40 is performed. In this modification, in the support substrate preparation step, electronic components 51 and wiring 52 are provided on the first surface 41 of the support substrate 40, as shown in FIG. 14A(b). Further, a reinforcing member 31 is provided on the second surface 42 of the support substrate 40. The reinforcing member 31, electronic component 51, and wiring 52 may be provided in any order on the support substrate 40.

Subsequently, a first step is performed in which a tensile stress T is applied to the base material 20 to elongate the base material 20. Subsequently, a second step is performed in which the electronic component 51 and the wiring 52 are provided on the first surface 21 side of the base material 20 that has been stretched by the tensile stress T. In this modification, in the second step, the reinforcing member 31, the electronic component 51, the wiring 52, and the reinforcing member 31 are placed on the first surface 21 of the base material 20 in an expanded state, as shown in FIG. 14A(c). The provided support substrate 40 is joined from the second surface 42 side of the support substrate 40.

After that, a third step of removing the tensile stress T from the base material 20 is performed. As a result, as shown by arrow C in FIG. 14A(d), the base material 20 contracts, and the support substrate 40 and wiring 52 bonded to the base material 20 are also deformed. The third elastic modulus of the support substrate 40 is larger than the first elastic modulus of the base material 20. Therefore, the support substrate 40 and the wiring 52 can be deformed as a bellows-shaped portion.

After the third step, a fourth step of providing a mounting adhesive layer X on the second surface 22 side of the base material 20 is performed (FIG. 14A(d)). That is, in this fourth step, a pasting surface X1 is pasted on the second surface 22 side of the base material 20, and a wiring board 10 is pasted on the second surface 22 side of the base material 20, and the wiring board 10 is pasted on the opposite side of this pasting surface X1. A mounting adhesive layer X having air permeability is provided, including a mounting surface X2 that comes into contact with the mounting object when the mounting surface is mounted on the mounting object (not shown). An example of a method is to form the entire surface using an applicator or screen printing, and then form cuts using a cutting plotter or laser processing. Further, when penetrating the side surface or forming a cavity inside, it may be formed in the base material 20 using a mold that forms a through hole or cavity. In addition, if an additional base material is included, after forming an adhesive on the additional base material, cut the mounting adhesive layer, which is a combination of the additional base material and adhesive, using a punching, cutting plotter, or laser cutter. There is also a way to form.
In this fourth step, for example, as shown in FIG. 14B, a pasting adhesive layer Y containing an adhesive is provided between the second surface 22 of the base material 20 and the mounting adhesive layer X. You may make it carry out the sticking process which sticks the adhesive layer X for mounting on the base material 20 via the adhesive layer Y for sticking. Examples of the method for forming the adhesive layer Y for pasting include an applicator and screen printing.
Further, an additional base material may be provided on the mounting adhesive layer Y. In this case, a through hole penetrating in the vertical direction is formed in the mounting adhesive layer provided with the additional base material, for example, as the above-mentioned cut to reduce the tensile strength, and the mounting adhesive layer Y Also, the additional layer N may not have any incisions formed therein.

Further, in this modification, the reinforcing member 31 is arranged on the second surface 42 of the support substrate 40 so as to overlap with the electronic component 51. Therefore, it is possible to suppress the electronic component 51 from being affected by the shrinkage of the base material 20 in the third step. This can prevent the electronic component 51 from being deformed or damaged.

(Second modification)
In the above-described embodiment and modification 1, an example was shown in which the electronic component 51 and the wiring 52 are supported by the support substrate 40 having a third elastic modulus higher than the first elastic modulus of the base material 20. However, it is not limited to this. As shown in FIG. 15, the electronic component 51 and the wiring 52 may be provided on the first surface 21 of the base material 20.

FIG. 16 is an enlarged cross-sectional view showing an example of the wiring 52 of the wiring board 10 shown in FIG. 15 and components around it. Also in this modification, a bellows-shaped portion 57 is formed in a portion of the wiring 52 that does not overlap with the reinforcing member 31, as in the above-described embodiment. Therefore, it is possible to suppress the total length of the wiring 52 from increasing and the cross-sectional area of the wiring 52 from decreasing due to deformation of the base material 20.

17(a) to (d) are diagrams for explaining a method of manufacturing the stretchable wiring board 10 shown in FIG. 15. FIG.

First, as shown in FIG. 17(a), a base material preparation step for preparing the base material 20 is performed. In this modification, in the base material preparation step, as shown in FIG. 17(a), a base material 20 having a reinforcing member 31 provided therein is prepared.

Subsequently, as shown in FIG. 17(b), a first step of applying tensile stress T to the base material 20 and elongating the base material 20 is performed. Subsequently, as shown in FIG. 17(c), a second step is performed in which electronic components 51 and wiring 52 are provided on the first surface 21 of the base material 20 which is stretched by the tensile stress T.

After that, a third step of removing the tensile stress T from the base material 20 is performed. As a result, as shown by arrow C in FIG. 17(d), the base material 20 contracts, and the wiring 52 provided on the base material 20 is also deformed. The reinforcing member 31 is arranged so as not to overlap the entire wiring 52 or most of the wiring 52. Therefore, the deformation of the wiring 52 occurs as a bellows-shaped portion is generated.

After the third step, a fourth step of providing a mounting adhesive layer X on the second surface 22 side of the base material 20 is performed (FIG. 17(d)). That is, in this fourth step, a pasting surface X1 is pasted on the second surface 22 side of the base material 20, and a wiring board 10 is pasted on the second surface 22 side of the base material 20, and the wiring board 10 is pasted on the opposite side of this pasting surface X1. A mounting adhesive layer X having air permeability is provided, including a mounting surface X2 that comes into contact with the mounting object when the mounting surface is mounted on the mounting object (not shown). Particularly, in this fourth step, a sticking adhesive layer Y containing adhesive is provided between the second surface 22 of the base material 20 and the mounting adhesive layer X, and the pasting adhesive layer Y is provided on the base material 20. A pasting process of pasting the mounting adhesive layer X through Y is carried out.

Further, in this modification, a reinforcing member 31 is arranged on the second surface 22 of the base material 20. Therefore, it is possible to suppress the portion of the base material 20 that is scheduled to overlap the electronic component 51 from expanding in the first step. Therefore, it is possible to suppress shrinkage of the portion of the base material 20 that overlaps with the electronic component 51 in the third step. By this, it is possible to suppress stress caused by the deformation of the base material 20 from being applied to the electronic component 51, and it is possible to suppress the electronic component 51 from being deformed or damaged.

(Third modification)
In the above-described embodiment and each modification example, the electronic component 51 is packaged in advance before being mounted on the wiring board 10. However, the present invention is not limited to this, and the electronic component 51 may be configured by mounting some of the components of the electronic component 51 on the wiring board 10 and then sealing some of the components. There may be.
As shown in FIGS. 18 and 19, a potting resin 50 may be provided to reinforce the packaged electronic component 51. In this case, as shown in FIG. 18, the resin 50 may cover the entire electronic component 51. Alternatively, as shown in FIG. 19, the resin 50 does not need to cover the entire electronic component 51. For example, the resin 50 may be located around the electronic component 51 between the end of the reinforcing member 31 and the end of the electronic component 51 so as to reinforce the periphery of the electronic component 51. In both the examples shown in FIGS. 18 and 19, the resin 50 is preferably located inside the end of the reinforcing member 31 (on the electronic component 51 side).

(Fourth modification)
In the above-described embodiment and each modification example, the electronic component 51 is a component made of a member different from each component of the wiring board 10. In the following modification, an example will be described in which the electronic component 51 includes a member that is integral with at least one of the plurality of components of the wiring board 10.

FIG. 20 is an enlarged cross-sectional view of a wiring board 10 according to a modified example. As shown in FIG. 20, electronic component 51 includes a conductive layer that is integral with the conductive layer that constitutes wiring 52 of wiring board 10. As shown in FIG. In the example shown in FIG. 20, the conductive layer that constitutes the wiring 52 and the conductive layer that constitutes the electronic component 51 are both located on the first surface 41 of the support substrate 40. A bellows-shaped portion 57 appears in the conductive layer constituting the wiring 52 . On the other hand, the reinforcing member 31 is overlaid on the conductive layer constituting the electronic component 51, so that no bellows-shaped portion appears in the conductive layer constituting the electronic component 51.

FIG. 21 is a plan view showing an example of the electronic component 51 shown in FIG. 20. In the example shown in FIG. 21, the conductive layer constituting the electronic component 51 has a wider width than the conductive layer constituting the wiring 52. The portion where the width of the conductive layer changes is the outer edge 512 of the electronic component 51. The electronic component 51 shown in FIG. 21 can function as a pad, for example. A probe for inspection, a terminal for rewriting software, etc. are connected to the pad.

FIG. 22 is a plan view showing another example of the electronic component 51 shown in FIG. 20. In the example shown in FIG. 22, the conductive layer constituting the electronic component 51 has a spirally extending shape. The portion where the conductive layer begins to extend spirally is the outer edge 512 of the electronic component 51. An electronic component 51 including a conductive layer having a predetermined pattern as shown in FIG. 22 can function as an antenna or a pressure sensor.

(Fifth modification)
FIG. 23 is a plan view showing a modified example of the wiring board 10. As shown in FIG. In addition to the wiring 52, the wiring board 10 is further provided with a cross wiring 59 that is laminated on the wiring 52 with an insulating layer 45 interposed therebetween. In this modification, the cross wiring 59 constitutes the electronic component 51. The intersecting wiring 59 extends to intersect with the wiring 52 in plan view. By providing the insulating layer 45 between the wiring 52 and the crossing wiring 59, it is possible to prevent the crossing wiring 59 from shorting with the wiring 52. As a material constituting the insulating layer 45, an organic resin such as polyimide, acrylic, urethane, or epoxy, or an inorganic material such as SiO ₂ or alumina may be used.

As shown in FIG. 23, the reinforcing member 31 is provided so as to straddle the conductive layer constituting the wiring 52 and the conductive layer of the cross wiring 59 constituting the electronic component 51. As a result, when stress such as elongation or bending is applied to the wiring board 10, the insulating layer 45 may crack or the insulation performance may deteriorate, resulting in a short circuit between the wiring 52 and the cross wiring 59. can be prevented.

(Modified example of wiring board)
In the above-described embodiment and each modification example, the wiring board 10 includes the electronic component 51 mounted on the first surface 21 side of the base material 20. However, the present invention is not limited to this, and the wiring board 10 may not include the electronic component 51. For example, the bellows-shaped portion 57 may be formed on the base material 20 without the electronic component 51 mounted thereon. Further, the support substrate 40 on which the electronic component 51 is not mounted may be bonded to the base material 20. Furthermore, the wiring board 10 may be shipped without the electronic component 51 mounted thereon.

Although several modifications to the embodiment described above have been described, it is of course possible to apply a plurality of modifications in combination as appropriate.

10 Wiring board 20 Base material 21 First surface 22 Second surface 31 Reinforcing member 40 Support substrate 41 First surface 42 Second surface 51 Electronic component 52 Wiring 53, 54 Peaks 55, 56 Valley 57 Bellows-shaped portion 60 Adhesive layer X Adhesive layer for mounting X1 Pasting surface X2 Mounting surface Y Adhesive layer for pasting Y1 First adhesive surface Y2 Second adhesive surface N Additional layer N1 First surface N2 Second surface

Claims (21)

A wiring board having stretchability,
a base material including a first surface and a second surface located on the opposite side of the first surface, and having a first elastic modulus;
Wiring located on the first surface side or the second surface side of the base material;
A bonding surface located on the second surface side of the base material and attached to the second surface side of the base material, and a bonding surface located on the opposite side of this bonding surface, the wiring board being mounted on the mounted object. an adhesive layer for mounting that includes a mounting surface that comes into contact with the object to be mounted and has air permeability;
a pasting adhesive layer located between the second surface of the base material and the mounting adhesive layer and containing an adhesive for pasting the mounting adhesive layer to the base material;
The elastic modulus of the adhesive layer for pasting is smaller than the first elastic modulus of the base material,
A wiring board , wherein a notch is formed in the adhesive layer for pasting . further comprising an additional layer located between the second surface of the base material and the attachment surface of the mounting adhesive layer, and having a first surface and a second surface opposite to the first surface,
The wiring board according to claim 1 , wherein the additional layer has a smaller elastic modulus than the first elastic modulus of the base material. 3. The wiring board according to claim 1, wherein the mounting adhesive layer contains an acrylic adhesive, a silicone adhesive, a urethane adhesive, or an epoxy adhesive. 4. The wiring board according to claim 3 , wherein the mounting adhesive layer has a notch formed therein. 5. The wiring board according to claim 1, wherein the mounting adhesive layer has lower hardness or tensile strength than the base material. The adhesive layer for pasting may be a silicone adhesive, a modified silicone adhesive, a mixture of a modified silicone adhesive and an epoxy adhesive, a urethane adhesive, an acrylic adhesive, or an epoxy adhesive. The wiring board according to claim 1, comprising any one of the above . 3. The wiring board according to claim 2, wherein the additional layer is a layer containing elastomer rubber, silicone rubber, gel, or a porous material. 8. The wiring board according to claim 1, wherein the mounting adhesive layer includes a material using nonwoven fabric, urethane, or foam. The wiring board according to any one of claims 1 to 8 , wherein the base material contains silicone rubber. The wiring board according to any one of claims 1 to 9 , wherein the wiring has a bellows-shaped portion including a plurality of peaks and valleys arranged along an in-plane direction of the first surface of the base material. . Any one of claims 1 to 10, further comprising a support substrate located between the wiring and the base material, having a third elastic modulus larger than the first elastic modulus, and supporting the wiring. The wiring board according to item 1. located inside the base material, on the first surface side of the base material, or on the second surface side of the base material, and when viewed along the normal direction of the first surface of the base material. 12. The reinforcing member according to claim 1, further comprising a reinforcing member that at least partially overlaps the electronic component mounted on the wiring board and has a second elastic modulus larger than the first elastic modulus. wiring board. A portion of the wiring that does not overlap with the reinforcing member when viewed along the normal direction of the first surface includes a plurality of peaks and valleys lined up in the in-plane direction of the first surface of the base material. The wiring board according to claim 12 , having a bellows-shaped portion including a portion. The wiring board according to claim 13 , wherein the amplitude of the bellows-shaped portion of the wiring is 1 μm or more. The wiring board according to claim 13 , wherein the reinforcing member includes a metal layer. The wiring board according to any one of claims 1 to 15 , wherein the wiring includes a plurality of conductive particles. The wiring board according to any one of claims 1 to 16 , further comprising an electronic component having an electrode located on the first surface side of the base material and electrically connected to the wiring. The resistance value of the wiring in a first state in which no tensile stress along the in-plane direction of the first surface of the base material is applied to the base material is referred to as a first resistance value, and the tensile stress is applied to the base material. When the resistance value of the wiring in a second state where the base material is elongated by 30% in the in-plane direction of the first surface compared to the first state is referred to as a second resistance value, 18. The wiring board according to claim 1, wherein a ratio of an absolute value of a difference between the first resistance value and the second resistance value is 20% or less. A method for manufacturing a stretchable wiring board, the method comprising:
A first step of elongating the base material by applying tensile stress to the base material, which includes a first surface and a second surface located on the opposite side of the first surface, and has a first elastic modulus;
a second step of providing wiring on the first surface side or the second surface side of the base material in an expanded state;
a third step of removing the tensile stress from the base material;
On the second surface side of the base material, an attachment surface that is attached to the second surface side of the base material, and an attachment surface located on the opposite side of this attachment surface when the wiring board is mounted on a mounted object. a fourth step of providing a mounting adhesive layer including a mounting surface in contact with the mounted object;
The elastic modulus of the mounting adhesive layer is smaller than the first elastic modulus of the base material,
In the fourth step, a pasting adhesive layer containing an adhesive is provided between the second surface of the base material and the mounting adhesive layer, and the pasting adhesive layer is attached to the base material through the pasting adhesive layer. a pasting step of pasting the mounting adhesive layer,
The elastic modulus of the adhesive layer for pasting is smaller than the first elastic modulus of the base material,
A method for manufacturing a wiring board , wherein a notch is formed in the adhesive layer for pasting . forming an additional layer located between the second surface of the base material and the attachment surface of the mounting adhesive layer and having a first surface and a second surface opposite to the first surface; With further processes,
20. The method for manufacturing a wiring board according to claim 19 , wherein the additional layer has a smaller elastic modulus than the first elastic modulus of the base material. The wiring board according to any one of claims 19 to 20 , wherein the wiring has a bellows-shaped portion including a plurality of peaks and valleys arranged along an in-plane direction of the first surface of the base material. manufacturing method.