JP2020126926A - Wiring board and method of manufacturing wiring board - Google Patents

Abstract

To provide a wiring board in which variation in a cycle of a bellows-shaped portion of a stretchable base material can be suppressed, and a method of manufacturing a wiring board.SOLUTION: A wiring board 10 comprises: a stretchable base material 20; a first wiring 521 located on a first surface 21 side of the base material; a second wiring 522, located on the first surface 21 side, intersecting with the first wiring 521 in a plan view, having a bellows-shaped portion including a plurality of peaks and valleys arranged along a first direction, which is one of in-plane directions of the first surface 21; and an insulating layer 30, located between the first wiring 521 and the second wiring 522 at an intersection of the first wiring 521 and the second wiring 522, insulating the first wiring 521 and the second wiring 522. A dimension of the insulating layer 30 in the first direction is twice or less a cycle of the bellows-shaped portion.SELECTED DRAWING: Figure 1

Description

Embodiments of the present disclosure relate to a wiring board including a base material and wiring located on the first surface side of the base material. The embodiment of the present disclosure also relates to a method for manufacturing a wiring board.

In recent years, research has been conducted on electronic devices having deformability such as elasticity. For example, it is known that a stretchable base material is formed with stretchable silver wiring, and a stretchable base material is formed with horseshoe-shaped wiring (see, for example, Patent Document 1). However, these types of electronic devices have a problem that the resistance value of the wiring is likely to change as the base material expands and contracts.

As another type of electronic device, for example, Patent Document 2 discloses a wiring board having a base material and wiring provided on the base material and having elasticity. In Patent Document 2, a manufacturing method is adopted 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 2 intends to operate the thin film transistor on the substrate well in both the stretched state and the relaxed state of the substrate.

JP, 2013-187308, A JP, 2007-281406, A

When the base material is in a relaxed state, the wiring provided on the base material has a bellows-shaped portion in which peaks and valleys repeatedly appear along the in-plane direction of the base material. In this case, when the base material is extended, the wiring can follow the extension of the base material by expanding the bellows-shaped portion in the in-plane direction. Therefore, according to the electronic device of the type having the bellows-shaped portion, it is possible to prevent the resistance value of the wiring from changing as the base material expands and contracts.

On the other hand, when a structure that is larger than the cycle of the bellows-shaped portion in the cycle direction of the bellows-shaped portion is provided adjacent to the bellows-shaped portion, the cycle of the bellows-shaped portion varies and damage such as breaking of the wiring occurs It may be lost.

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

One embodiment of the present disclosure is a stretchable base material, a first wiring located on the first surface side of the base material, and a second wiring located on the first surface side, and in a plan view. A second wiring that has a bellows-shaped portion that intersects the first wiring and that is arranged along a first direction that is one of the in-plane directions of the first surface; An insulating layer located between the first wiring and the second wiring at an intersection of the first wiring and the second wiring and insulating the first wiring and the second wiring; In the wiring board, the dimension of the insulating layer in the first direction is not more than twice the cycle of the bellows-shaped portion.

In the wiring board according to the embodiment of the present disclosure, the second wiring may be located on the insulating layer, and the insulating layer may be located on the first wiring at the intersection.

The wiring board according to an embodiment of the present disclosure may further include a stress control layer located on the second wiring and controlling a stress acting on the second wiring.

In a wiring board according to an embodiment of the present disclosure, a side surface of the insulating layer in the first direction is inclined at least partially in a direction away from the bellows-shaped portion with respect to a normal direction of the first surface. Good.

In the wiring board according to the embodiment of the present disclosure, the insulating layer may have a dome shape that protrudes along a direction normal to the first surface.

In the wiring board according to the embodiment of the present disclosure, the first wiring may be located on the insulating layer and the insulating layer may be located on the second wiring at the intersection.

In the wiring board according to the embodiment of the present disclosure, the first wiring may have a second bellows-shaped portion including a plurality of peaks and valleys arranged in the first direction.

In the wiring board according to the embodiment of the present disclosure, the insulating layer may have a bending rigidity higher than that of the base material.

In the wiring board according to the embodiment of the present disclosure, the insulating layer may have an elastic coefficient larger than that of the base material.

One embodiment of the present disclosure is a stretchable base material, and a wiring located on the first surface side of the base material, and along a first direction that is one of in-plane directions of the first surface. A wiring having a bellows-shaped portion including a plurality of peaks and valleys arranged side by side, and an electronic component located on the first surface side and connected to the wiring via a connecting portion, In the wiring board, the dimension between the one end and the other end in the first direction is equal to or less than twice the cycle of the bellows-shaped portion.

One embodiment of the present disclosure is a stretchable base material, and a wiring located on the first surface side of the base material, and along a first direction that is one of in-plane directions of the first surface. Wiring having a bellows-shaped portion including a plurality of peaks and valleys arranged side by side, an electronic component located on the first surface side and connected to the wiring, and located on the electronic component, the electronic component And a sealing material for sealing, the dimension between one end and the other end of the sealing material in the first direction is not more than twice the cycle of the bellows-shaped portion.

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

In a wiring board according to an embodiment of the present disclosure, the amplitude of a peak portion and a valley portion that appear in a portion of the second surface of the base material, which is located on the opposite side of the first surface, overlapping the bellows-shaped portion, It may be smaller than the amplitude of the peaks and valleys that appear in the portion of the first surface of the material that overlaps the bellows-shaped portion.

In a wiring board according to an embodiment of the present disclosure, the amplitude of a peak portion and a valley portion that appear in a portion of the second surface of the base material, which is located on the opposite side of the first surface, overlapping the bellows-shaped portion, It may be 0.9 times or less the amplitude of the peaks and valleys that appear in the portion of the first surface of the material that overlaps the bellows-shaped portion.

According to an embodiment of the present disclosure, a stretching step of stretching a base material by applying tensile stress to a stretchable base material and providing a first wiring on the first surface side of the base material in the stretched state. A first wiring step, a second wiring step of providing a second wiring on the first surface side of the base material so as to intersect the first wiring in a plan view, and a first wiring and a second wiring An insulating step of providing an insulating layer that insulates the first wiring and the second wiring so as to be located between the first wiring and the second wiring at the intersection, and the tensile stress from the base material. After removing the tensile stress from the base material, the second wiring is provided along a first direction which is one of in-plane directions of the first surface of the base material. It is a manufacturing method of a wiring board which has a bellows-shaped part containing a plurality of peaks and valleys which are located in a line, and the size of the insulating layer in the 1st direction is two times or less of the cycle of the bellows-shaped part.

According to an embodiment of the present disclosure, a stretching step of stretching a base material by applying tensile stress to a stretchable base material, and a wiring step of providing wiring on the first surface side of the base material in the stretched state. And a component connecting step of connecting an electronic component to the wiring through a connecting portion, and a contracting step of removing the tensile stress from the base material, and after the tensile stress is removed from the base material, The wiring has a bellows-shaped portion including a plurality of peaks and valleys arranged along a first direction, which is one of the in-plane directions of the first surface of the base material, and the first portion of the connection portion. In the method for manufacturing a wiring board, the dimension between one end and the other end in the direction is not more than twice the cycle of the bellows-shaped portion.

According to an embodiment of the present disclosure, a stretching step of stretching a base material by applying tensile stress to a stretchable base material, and a wiring step of providing wiring on the first surface side of the base material in the stretched state. A component connecting step of connecting an electronic component to the wiring, a sealing step of sealing the electronic component with a sealing material, and a shrinking step of removing the tensile stress from the base material, After the tensile stress is removed from the wiring, the wiring is a bellows-shaped portion including a plurality of peaks and valleys arranged along a first direction which is one of in-plane directions of the first surface of the base material. And a dimension between one end and the other end of the sealing material in the first direction is equal to or less than twice the cycle of the bellows-shaped portion.

According to the embodiment of the present disclosure, it is possible to suppress variations in the bellows-shaped portion of the base material.

It is a top view which shows the wiring board which concerns on embodiment. It is sectional drawing which shows the case where the wiring board of FIG. 1 is cut|disconnected along line II-II. It is sectional drawing which expands and shows the wiring board shown in FIG. It is sectional drawing which shows an example of the bellows-shaped part which appears on a base material. FIG. 9 is a diagram for explaining the manufacturing method for the wiring board shown in FIG. 2. It is a figure for explaining an example of the size of the 1st direction of an insulating layer. It is sectional drawing which shows the example of a changed completely type of wiring board. It is sectional drawing which shows the example of a changed completely type of wiring board. It is a top view showing a modification of a wiring board. It is sectional drawing which shows the case where the wiring board of FIG. 9 is cut|disconnected along line XX. It is sectional drawing which shows the example of a changed completely type of wiring board. It is sectional drawing which shows the example of a changed completely type of wiring board. FIG. 9 is a plan view showing a modification of the planar shape of the insulating layer. It is sectional drawing which shows the case where the wiring board of FIG. 13 is cut|disconnected along line XIV-XIV. FIG. 9 is a plan view showing a modification of the planar shape of the insulating layer. FIG. 9 is a plan view showing a modification of the planar shape of the insulating layer. FIG. 9 is a plan view showing a modification of the planar shape of the insulating layer. FIG. 9 is a plan view showing a modification of the planar shape of the insulating layer. It is sectional drawing which shows the example of a changed completely type of wiring board. FIG. 17 is a diagram illustrating the method for manufacturing the wiring board shown in FIG. 16. It is sectional drawing which shows the example of a changed completely type of wiring board. FIG. 19 is a diagram illustrating the method for manufacturing the wiring board shown in FIG. 18. It is a top view showing a modification of a wiring board. It is sectional drawing which shows the 1st Example of a wiring board. It is sectional drawing which shows the 4th Example of a wiring board.

Hereinafter, the configuration of the wiring board and the manufacturing method thereof according to the embodiment of the present disclosure will be described in detail with reference to the drawings. The embodiments described below are examples of the embodiments of the present disclosure, and the present disclosure should not be construed as being limited to these embodiments. Further, in the present specification, terms such as “substrate”, “base material”, “sheet” and “film” are not distinguished from each other based only on the difference in designation. For example, the "base material" is a concept including members such as substrates, sheets and films. Further, as used in the present specification, terms such as “parallel” and “orthogonal” and values of length and angle, etc. that specify shapes and geometric conditions and their degrees are bound to strict meanings. Instead, the same function should be interpreted including the range to the extent that it can be expected. Further, in the drawings referred to in this embodiment, the same portions or portions having similar functions are denoted by the same reference numerals or similar reference numerals, and repeated description thereof may be omitted. Further, the dimensional ratios in the drawings may be different from the actual ratios for convenience of description, or a part of the configuration may be omitted from the drawings.

Hereinafter, an embodiment of the present disclosure will be described with reference to FIGS. 1 to 5.

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

The wiring board 10 includes a base material 20, an insulating layer 30, a first wiring 521, and a second wiring 522. Hereinafter, each component of the wiring board 10 will be described.

〔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 first wiring 521 and second wiring 522 sides 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 μm or more and 10 mm or less, and more preferably 20 μm or more and 3 mm or less. By setting the thickness of the base material 20 to 10 μm or more, the durability of the base material 20 can be ensured. Further, by setting the thickness of the base material 20 to 10 mm or less, it is possible to ensure the comfort of mounting the wiring board 10. If the thickness of the base material 20 is too small, the elasticity of the base material 20 may be impaired.

The stretchability of the base material 20 means that the base material 20 can expand and contract, that is, it can be expanded from a non-expanded state which is a normal state, and can be restored when released from this expanded state. A property that can be done. The non-stretched state is the state of the base material 20 when no tensile stress is applied. In this embodiment, the stretchable substrate is preferably capable of stretching 1% or more from an unstretched state without breaking, more preferably 20% or more, and further preferably 75%. The above can be extended. By using the base material 20 having such an ability, the wiring board 10 can have stretchability as a whole. Furthermore, the wiring board 10 can be used in products and applications that require high expansion and contraction, such as being attached to a part of the body such as a human arm. It is generally said that a product attached to a person's armpit must have a stretchability of 72% in the vertical direction and 27% in the horizontal direction. Further, it is said that a product attached to a person's knees, elbows, buttocks, ankles, and armpits needs to have elasticity of 26% or more and 42% or less in the vertical direction. Further, it is said that a product attached to other parts of a person needs elasticity of less than 20%.

In addition, it is preferable that the difference between the shape of the base material 20 in the non-stretched state and the shape of the base material 20 when it is stretched from the non-stretched state and then returned to the non-stretched state is small. This difference is also referred to as a shape change in the following description. The shape change of the base material 20 is, for example, 20% or less in area ratio, more preferably 10% or less, and further preferably 5% or less. By using the base material 20 having a small shape change, it becomes easy to form a bellows-shaped portion described later.

An elastic coefficient of the base material 20 can be given as an example of the parameter indicating the elasticity of the base material 20. The elastic modulus of the base material 20 is, for example, 10 MPa or less, and more preferably 1 MPa or less. By using the base material 20 having such an elastic coefficient, the entire wiring board 10 can be made to have elasticity. The elastic modulus of the base material 20 may be 1 kPa or more.

As a method of calculating the elastic coefficient of the base material 20, it is possible to employ a method of performing a tensile test according to JIS K6251 using a sample of the base material 20. It is also possible to employ a method in which the elastic coefficient of the sample of the base material 20 is measured by the nanoindentation method according to ISO14577. A nano indenter can be used as a measuring device used in the nano indentation method. As a method of preparing a sample of the base material 20, a method of taking out a part of the base material 20 from the wiring board 10 as a sample or a method of taking out a part of the base material 20 before forming the wiring board 10 as a sample is considered. To be In addition, as a method of calculating the first elastic coefficient of the base material 20, a method of analyzing a material forming the base material 20 and calculating the elastic coefficient of the base material 20 based on an existing database of the material is used. It can also be adopted. The elastic modulus in the present application is an elastic coefficient under an environment of 25°C.

The bending rigidity of the base material 20 can be given as another example of the parameter indicating the elasticity of the base material 20. The bending rigidity is the product of the second moment of area of the target member and the elastic modulus of the material forming the target member, and the unit is N·m ² or Pa·m ⁴ . The geometrical moment of inertia of the base material 20 is calculated based on the cross section when the portion of the base material 20 overlapping the second wiring 522 is cut by the plane orthogonal to the expansion/contraction direction of the wiring board 10.

An example of the material forming the base material 20 is an elastomer. Further, as the material of the base material 20, for example, cloth such as woven fabric, knitted fabric, and non-woven fabric can be used. As the elastomer, a general thermoplastic elastomer and a thermosetting elastomer can be used, and specifically, a polyurethane elastomer, a styrene elastomer, a nitrile elastomer, an olefin elastomer, a vinyl chloride elastomer, an ester elastomer, Amide elastomer, 1,2-BR elastomer, fluorine elastomer, silicone rubber, urethane rubber, fluorine rubber, polybutadiene, polyisobutylene, polystyrene butadiene, polychloroprene and the like can be used. Considering mechanical strength and abrasion resistance, it is preferable to use urethane elastomer. Further, the base material 20 may include silicone. Silicone has excellent heat resistance, chemical resistance, and flame retardancy, and is preferable as a material for the base material 20.

〔wiring〕
The first wiring 521 and the second wiring 522 are members having conductivity, which are located on the first surface 21 side of the base material 20. The first wiring 521 and the second wiring 522 are, for example, electrically connected to an electronic component (not shown) and used for inputting/outputting signals to/from the electronic component and supplying power. As shown in FIG. 1, the second wiring 522 intersects the first wiring 521 in a plan view. Hereinafter, a portion where the first wiring 521 and the second wiring 522 intersect in a plan view is also referred to as an intersection portion 52C.

FIG. 3 is an enlarged sectional view showing the wiring board 10 shown in FIG. As shown in FIG. 3, the second wiring 522 has a bellows-shaped portion 57 including a plurality of peaks 53 and valleys 55 arranged along the first direction D1 which is one of the in-plane directions of the first surface 21. Have. The first direction D1 is a direction in which the peaks 53 and the valleys 55 of the bellows-shaped portion 57 appear repeatedly.

In the manufacturing process of the wiring board 10, the first wiring 521 is provided on the base material 20 in a state of being stretched in the first direction D1 by tensile stress, along the direction orthogonal to the first direction D1. On the other hand, the second wiring 522 is provided along the first direction D1 on the base material 20 that is stretched in the first direction D1 by the tensile stress. In this case, when the tensile stress is removed from the base material 20 and the base material 20 contracts, the second wiring 522 is deformed into a bellows shape and has the bellows-shaped portion 57, as shown in FIG.

The bellows-shaped portion 57 includes a mountain portion and a valley portion in the normal direction of the first surface 21 of the base material 20. In FIG. 3, reference numeral 53 represents a mountain portion appearing on the front surface of the second wiring 522, and reference numeral 54 represents a mountain portion appearing on the back surface of the second wiring 522. Further, reference numeral 55 represents a valley portion appearing on the front surface of the second wiring 522, and reference numeral 56 represents a valley portion appearing on the back surface of the second wiring 522. The front surface is a surface of the surface of the second wiring 522 which is located on the side far from the base material 20, and the back surface is the surface of the surface of the second wiring 522 which is located on the side close to the base material 20. Further, in FIG. 3, reference numerals 26 and 27 represent peaks and valleys appearing on the first surface 21 of the base material 20. When the base material 20 is deformed so that the peaks 26 and the valleys 27 appear on the first surface 21, the second wiring 522 is deformed into a bellows shape and has the bellows-shaped portion 57. The crests 26 of the first surface 21 of the base material 20 correspond to the crests 53 and 54 of the bellows-shaped part 57 of the second wiring 522, and the troughs 27 of the first surface 21 of the base material 20 are the second wiring. It corresponds to the valleys 55 and 56 of the bellows-shaped portion 57 of 522.

In the example shown in FIG. 3, the second wiring 522 extends parallel to the first direction D1. In addition, the base material 20 has a rectangular shape including long sides parallel to the first direction D1. Although FIG. 3 shows an example in which a plurality of peaks and valleys of the bellows-shaped portion 57 are arranged at a constant cycle, the present invention is not limited to this. Although not shown, the plurality of peaks and troughs of the bellows-shaped portion 57 may be arranged irregularly along the first direction D1. For example, the interval between two peaks adjacent to each other in the first direction D1 may not be constant.

In FIG. 3, symbol S1 represents the amplitude of the bellows-shaped portion 57 on the surface of the second wiring 522 in the normal direction of the base material 20. 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 second wiring 522 easily deforms following the expansion of the base material 20. Further, the amplitude S1 may be, for example, 500 μm or less.

The amplitude S1 is obtained by measuring the distance in the normal direction of the first surface 21 between the adjacent peaks 53 and valleys 55 over a certain range in the lengthwise direction of the second wiring 522, for example. It is calculated by calculating the average. The “certain range in the lengthwise direction of the second wiring 522” is, for example, 10 mm. As a measuring device for measuring the distance between the adjacent crests 53 and valleys 55, a non-contact measuring device using a laser microscope or the like may be used, or a contact measuring device may be used. .. Further, the distance between the adjacent ridges 53 and valleys 55 may be measured based on an image such as a cross-sectional photograph. The same applies to the method of calculating the amplitudes S2, S3, and S4, which will be described later.

In FIG. 3, symbol S2 represents the amplitude of the bellows-shaped portion 57 on the back surface of the second wiring 522. 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. Further, in FIG. 3, reference numeral S3 represents the amplitudes of the peak portion 26 and the valley portion 27 that appear on the first surface 21 of the base material 20 in the portion that overlaps the bellows-shaped portion 57. As shown in FIG. 3, when the back surface of the second wiring 522 is located on the first surface 21 of the base material 20, the amplitude S3 of the peak portion 26 and the valley portion 27 of the first surface 21 of the base material 20 is It is equal to the amplitude S2 of the bellows-shaped portion 57 on the back surface of the second wiring 522.

Although FIG. 3 shows an example in which the bellows-shaped portion does not appear on the second surface 22 of the base material 20, the present invention is not limited to this. As shown in FIG. 4, a bellows-shaped portion may appear on the second surface 22 of the base material 20. In FIG. 4, reference numerals 28 and 29 represent peaks and valleys that appear on the second surface 22 of the base material 20 in the wiring region 24. In the example shown in FIG. 4, the crests 28 of the second surface 22 appear at positions overlapping the troughs 27 of the first surface 21, and the troughs 29 of the second surface 22 correspond to the crests 26 of the first surface 21. They appear in overlapping positions. Although not shown, the positions of the crests 28 and the troughs 29 of the second surface 22 of the base material 20 may not overlap the troughs 27 and the crests 26 of the first surface 21. The number or cycle of the peaks 28 and valleys 29 of the second surface 22 of the base material 20 may be the same as or different from the number or cycle of the peaks 26 and valleys 27 of the first surface 21. May be. For example, the cycle of the crests 28 and the valleys 29 of the second surface 22 of the base material 20 may be longer than the cycle of the crests 26 and the valleys 27 of the first surface 21. In this case, the cycle of the crests 28 and the valleys 29 of the second surface 22 of the base material 20 may be 1.1 times or more the cycle of the crests 26 and the valleys 27 of the first surface 21. 0.2 times or more, 1.5 times or more, or 2.0 times or more. It should be noted that “the cycle of the crests 28 and the valleys 29 of the second surface 22 of the base material 20 is larger than the cycle of the crests 26 and the valleys 27 of the first surface 21 ”is the second cycle of the base material 20. This is a concept including the case where the peaks and valleys do not appear on the surface 22.

In FIG. 4, reference numeral S4 represents the amplitude of the crests 28 and the troughs 29 that appear on the second surface 22 of the base material 20 in the portion that overlaps the bellows-shaped portion 57. The amplitude S4 of the second surface 22 may be the same as or different from the amplitude S3 of the first surface 21. For example, the amplitude S4 of the second surface 22 may be smaller than the amplitude S3 of the first surface 21. 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 of the amplitude S3 of the first surface 21. Good. Further, the amplitude S4 of the second surface 22 may be 0.1 times or more, or 0.2 times or more of the amplitude S3 of the first surface 21. When the thickness of the base material 20 is small, the ratio of the amplitude S4 of the second surface 22 to the amplitude S3 of the first surface 21 tends to be large. In addition, "the amplitudes of the peaks 28 and the valleys 29 of the second surface 22 of the base material 20 are smaller than the amplitudes of the peaks 26 and the valleys 27 of the first surface 21" mean that This is a concept including the case where the peaks and valleys do not appear on the surface 22.

Further, FIG. 4 shows an example in which the positions of the crests 28 and the troughs 29 of the second surface 22 match the positions of the troughs 27 and the crests 26 of the first surface 21, but the present invention is not limited to this. There is no such thing. For example, the positions of the crests 28 and the troughs 29 of the second surface 22 may be displaced from the positions of the troughs 27 and the crests 26 of the first surface 21 in the first direction D1. In this case, the shift amount is, for example, 0.1×F1 or more, and may be 0.2×F1 or more.

The material of the second wiring 522 may be any material that can follow the expansion and contraction of the base material 20 by utilizing the elimination and generation of the bellows-shaped portion 57. The material of the first wiring 521 may be the same as the material of the second wiring 522. The material of the second wiring 522 may or may not have elasticity itself. Examples of the material that does not have elasticity by itself that can be used for the second wiring 522 include metals such as gold, silver, copper, aluminum, platinum, and chromium, and alloys containing these metals. When the material of the second wiring 522 itself does not have elasticity, a metal film can be used as the second wiring 522. When the material itself used for the second wiring 522 has elasticity, the elasticity of the material is similar to that of the base material 20, for example. Examples of the material having elasticity itself that can be used for the second wiring 522 include a conductive composition containing conductive particles and an elastomer. The conductive particles may be any particles that can be used for wiring, and examples thereof include particles of gold, silver, copper, nickel, palladium, platinum, carbon and the like. Among them, silver particles are preferably used.

Preferably, the second wiring 522 has a structure having resistance to deformation. For example, the second wiring 522 has a base material and a plurality of conductive particles dispersed in the base material. In this case, by using a deformable material such as resin as the base material, the second wiring 522 can also be deformed according to the expansion and contraction of the base material 20. Further, the conductivity of the second wiring 522 is maintained by setting the distribution and shape of the conductive particles so that the contact between the plurality of conductive particles is maintained even when the deformation occurs. You can

As a material forming the base material of the second wiring 522, a general thermoplastic elastomer and a thermosetting elastomer can be used, and for example, a styrene elastomer, an acrylic elastomer, an olefin elastomer, a urethane elastomer, and a silicone. Rubber, urethane rubber, fluororubber, nitrile rubber, polybutadiene, polychloroprene and the like can be used. Of these, resins and rubbers containing urethane-based or silicone-based structures are preferably used from the viewpoint of stretchability and durability. Further, as the material forming the conductive particles of the second wiring 522, for example, particles of silver, copper, gold, nickel, palladium, platinum, carbon or the like can be used. Among them, silver particles are preferably used.

The thickness of the second wiring 522 may be a thickness that can withstand the expansion and contraction of the base material 20, and is appropriately selected according to the material of the second wiring 522 and the like. For example, when the material of the second wiring 522 does not have elasticity, the thickness of the second wiring 522 can be in the range of 25 nm or more and 50 μm or less, and preferably in the range of 50 nm or more and 10 μm or less. More preferably, it is in the range of 100 nm or more and 5 μm or less. When the material of the second wiring 522 has elasticity, the thickness of the second wiring 522 can be in the range of 5 μm or more and 60 μm or less, preferably in the range of 10 μm or more and 50 μm or less, and 20 μm. More preferably, it is within the range of 40 μm or less. The width of the second wiring 522 is, for example, 50 μm or more and 10 mm or less.

The method of forming the second wiring 522 is appropriately selected according to the material and the like. For example, a method of forming a metal film on the base material 20 or on a support substrate 40 described later in FIG. 12 by a vapor deposition method, a sputtering method, a plating method or the like, and then patterning the metal film by a photolithography method can be mentioned. When the material of the second wiring 522 itself has elasticity, for example, the conductive composition containing the conductive particles and the elastomer is patterned on the base material 20 or the support substrate 40 by a general printing method. The method of printing in the shape of a circle is mentioned. Among these methods, a printing method that can be manufactured with high material efficiency and at low cost can be preferably used.

The advantage that the bellows-shaped portion 57 is formed on the second wiring 522 will be described. As described 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 expand due to elastic deformation. Here, if the second wiring 522 is similarly expanded by elastic deformation, the total length of the second wiring 522 increases and the cross-sectional area of the second wiring 522 decreases, so that the resistance value of the second wiring 522 increases. End up. It is also conceivable that the elastic deformation of the second wiring 522 may cause damage such as cracks in the second wiring 522.

On the other hand, in the present embodiment, the second wiring 522 has the bellows-shaped portion 57. Therefore, when the base material 20 extends, the second wiring 522 follows the extension of the base material 20 by deforming so as to reduce the undulations of the bellows-shaped portion 57, that is, by eliminating the bellows shape. be able to. Therefore, it is possible to prevent the total length of the second wiring 522 from increasing as the base material 20 extends and the cross-sectional area of the second wiring 522 from decreasing. This can prevent the resistance value of the second wiring 522 from increasing due to the expansion of the wiring board 10. In addition, it is possible to prevent the second wiring 522 from being damaged such as a crack.

[Insulation layer]
The insulating layer 30 is a layer provided on the wiring board 10 to insulate the first wiring 521 and the second wiring 522. The insulating layer 30 is located between the first wiring 521 and the second wiring 522 at the intersection 52C of the first wiring 521 and the second wiring 522, and electrically connects the first wiring 521 and the second wiring 522. Insulate. The dimension of the insulating layer 30 in the first direction D1 of the in-plane directions and the direction orthogonal to the first direction D1 is larger than the line width of the wirings 521 and 522. In the example shown in FIGS. 1 and 2, the size of the insulating layer 30 in the first direction D1 is three times or more the size of the first wiring 521 in the first direction D1. Further, in the example shown in FIGS. 1 to 4, the second wiring 522 is located on the insulating layer 30 and the insulating layer 30 is located on the first wiring 521 at the intersection 52C.

The insulating layer 30 has a thickness necessary to insulate the first wiring 521 and the second wiring 522. The thickness of the insulating layer 30 may be in the range of 0.2 μm or more and 1000 μm or less, preferably in the range of 1 μm or more and 50 μm or less, and more preferably in the range of 5 μm or more and 10 μm or less.

The insulating layer 30 may have a modulus of elasticity larger than that of the base material 20. The elastic coefficient of the insulating layer 30 is preferably 1 GPa or more. If the elastic coefficient of the insulating layer 30 is too soft, the metal wiring 522 on the insulating layer 30 may be disconnected due to external stress or the like. The method of calculating the elastic coefficient of the insulating layer 30 is appropriately determined according to the form of the insulating layer 30. For example, the method of calculating the elastic coefficient of the insulating layer 30 may be the same as or different from the method of calculating the elastic coefficient of the base material 20 described above. The elastic modulus of the support substrate 40 described later is also the same. For example, as a method of calculating the elastic coefficient of the insulating layer 30 or the supporting substrate 40, a method of using a sample of the insulating layer 30 or the supporting substrate 40 and performing a tensile test according to ASTM D882 can be adopted. ..

As a material forming the insulating layer 30, a general thermoplastic elastomer and a thermosetting elastomer can be used. For example, a styrene elastomer, an acrylic elastomer, an olefin elastomer, a urethane elastomer, a silicone rubber, a urethane rubber. , Fluororubber, nitrile rubber, polybutadiene and polychloroprene.

The characteristics of the insulating layer 30 may be expressed by bending rigidity instead of elastic modulus. The second moment of area of the insulating layer 30 is calculated based on the cross section when the insulating layer 30 is cut by the plane orthogonal to the expansion/contraction direction of the wiring board 10. The flexural rigidity of the insulating layer 30 may be 1 time or more, more preferably 2 times or more, and further preferably 10 times or more that of the base material 20.

Examples of the method of forming the insulating layer 30 include a method of patterning a resin material by a photolithography method and a method of printing a resin material by a printing method such as screen printing.

Since the insulating layer 30 has a predetermined thickness, a dimension and rigidity in the first direction D1 at a position adjacent to the bellows-shaped portion 57, it may affect the cycle of the bellows-shaped portion 57. If the dimension of the insulating layer 30 in the first direction D1 is larger than twice the period F1 of the bellows-shaped portion 57, the period F1 of the bellows-shaped portion 57 varies, so that the second wiring 522 may be broken or otherwise damaged. May occur.

On the other hand, the dimension A of the insulating layer 30 in the first direction D1 in the present embodiment is not more than twice the cycle F1 of the bellows-shaped portion 57. Accordingly, it is possible to suppress variations in the period F1 of the bellows-shaped portion 57. By suppressing the variation of the period F1 of the bellows-shaped portion 57, it is possible to prevent the second wiring 522 from being broken or otherwise damaged.

The dimension A of the insulating layer 30 in the first direction D1 is preferably 0.01 times or more and 2 times or less, and more preferably 0.2 times or more and 1.0 times or less, the period F1 of the bellows-shaped portion 57. More preferable. If the dimension A of the insulating layer 30 is too small, it becomes difficult to properly form the insulating layer 30.

For the period F1 of the bellows-shaped portion 57, for example, the distance in the first direction D1 between the adjacent mountain portions 53 is measured over a certain range in the length direction of the second wiring 522, and the average thereof is calculated. Is calculated by The period F1 may be the average of the distances in the first direction D1 between at least three peaks 53 counted from the side close to the intersection 52C. As a measuring device for measuring the distance between the adjacent mountain portions 53, a non-contact measuring device using a laser microscope or the like may be used, or a contact measuring device may be used. Further, the distance between the adjacent mountain portions 53 may be measured by analyzing an image such as a plane photograph or a cross-sectional photograph of the bellows-shaped portion 57 taken by an optical microscope with a computer.

(Method of manufacturing wiring board)
Hereinafter, a method of manufacturing the wiring board 10 will be described with reference to FIGS.

First, as shown in FIG. 5A, a base material preparing step of preparing a base material 20 having elasticity is performed. Subsequently, as shown in FIG. 5B, a stretching step of stretching the substrate 20 by applying a tensile stress T to the substrate 20 is performed.

After performing the extending step, as shown in FIG. 5B, the first wiring step of providing the first wiring 521 on the first surface 21 of the base material 20 in the state of being extended by the tensile stress T is performed.

After the first wiring step is performed, as shown in FIG. 5C, the first wiring 521 and the second wiring 521 are formed on the first wiring 521 at a planned formation position of an intersection 52C with a second wiring 522 described later. An insulating step of providing an insulating layer 30 that insulates 522 is performed. The insulating step is a step of providing the insulating layer 30 so as to be located between the first wiring 521 and the second wiring 522 at the intersection 52C. In the insulating step, the dimension A of the insulating layer 30 in the first direction D1 is formed to be equal to or less than twice the period F1 of the bellows shaped portion 57 formed in the shrinking step described later. The dimension A of the insulating layer 30 in the first direction D1 that is equal to or less than twice the period F1 of the bellows-shaped portion 57 can be acquired in advance by simulation or experiment.

After performing the insulating step, as shown in FIG. 5D, a second wiring step of providing a second wiring 522 on the first surface 21 of the base material 20 so as to intersect the first wiring 521 in a plan view is performed. carry out.

After performing the second wiring step, as shown in FIG. 5E, a shrinking step for removing the tensile stress from the base material 20 is performed. As a result, as shown by the arrow C in FIG. 5E, the base material 20 contracts, and the second wiring 522 provided on the base material 20 also deforms. As a result, the bellows-shaped portion 57 having a period F1 that is ½ or more of the dimension A of the insulating layer 30 in the first direction D1 is formed on the second wiring 522.

Note that, as shown in FIG. 6A, the insulating layer 30 is formed in a strictly flat dome state in the insulating step, so that the thickness of the insulating layer 30 on the end side in the first direction D1 is reduced. The thickness may be smaller than the thickness of the insulating layer 30 on the center side in the first direction D1. In this case, as shown in FIG. 6B, when the tensile stress T is removed and the substrate 20 contracts, the insulating layer 30 is formed on the end side in the first direction D1 according to the wave of the bellows-shaped portion 57. It may be deformed. In this case, the dimension A of the insulating layer 30 in the first direction D1 may be defined as the dimension A of the insulating layer 30 on the center side in the first direction D1 that is hardly deformed when the substrate 20 contracts. The dimension A of the insulating layer 30 on the center side in the first direction D1 is 50% to 100% on the center side in the first direction D1 with respect to the dimension of the insulating layer 30 in the entire range in the first direction D1. It becomes a dimension. As the insulating layer 30 is more rigid, the insulating layer 30 is less likely to be deformed when the substrate 20 contracts, and thus the dimension A approaches 100%. On the other hand, when the hardness of the insulating layer 30 is about the same as that of the stress control layer 7 described in FIG. 11, the dimension A is 50%.

As described above, in the present embodiment, the dimension A of the insulating layer 30 in the first direction D1 is equal to or less than the period F1 of the bellows-shaped portion 57. As a result, it is possible to suppress the variation in the period F1 of the bellows-shaped portion 57 and prevent the second wiring 522 from being broken or otherwise damaged.

The wiring board 10 is used in the fields of healthcare, medical care, nursing care, electronics, sports/fitness, beauty, mobility, livestock/pets, amusement, fashion/apparel, security and military. , Distribution field, education field, building materials/furniture/decoration field, environmental energy field, agriculture, forestry and fisheries field, robot field, etc. For example, a product to be attached to a part of the body such as a person's arm is configured using the wiring board 10 according to the present embodiment. Since the wiring board 10 can be stretched, for example, by mounting the wiring board 10 in a stretched state on the body, the wiring board 10 can be brought into closer contact with a part of the body. Therefore, a good wearing feeling can be realized. In addition, it is possible to prevent the resistance value of the second wiring 522 from decreasing when the wiring board 10 is expanded, so that good electrical characteristics of the wiring board 10 can be realized. In addition, since the wiring board 10 can be extended, it can be installed or incorporated along a curved surface or a three-dimensional shape, not limited to a living body such as a person. Examples of such products include vital sensors, masks, hearing aids, toothbrushes, bandages, compresses, contact lenses, artificial hands, artificial legs, artificial eyes, catheters, gauze, drug packs, bandages, disposable bioelectrodes, diapers, home appliances, sportswear. , Wristbands, hemaki, gloves, swimwear, supporters, balls, rackets, liquid medicine beauty masks, electrostimulation diet products, pocket furnaces, automobile interiors, seats, instrument panels, strollers, drones, wheelchairs, tires, collars, leads, haptics devices , Place mats, hats, clothes, glasses, shoes, insoles, socks, stockings, innerwear, mufflers, ear pads, bags, accessories, rings, artificial nails, watches, personal ID recognition devices, helmets, packages, IC tags, pets Examples include bottles, stationery, books, carpets, sofas, bedding, lighting, door knobs, vases, beds, mattresses, cushions, wireless power feeding antennas, batteries, vinyl houses, robot hands, and robot exteriors.

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

(First modification)
First, with reference to FIG. 7, a first modification in which the vertical relationship between the first wiring 521 and the second wiring 522 at the intersection 52C is reversed will be described. FIG. 7 is a cross-sectional view showing a first modification of wiring board 10.

1 to 5A to 5E, an example of the wiring board 10 in which the second wiring 522 is located on the insulating layer 30 and the insulating layer 30 is located on the first wiring 521 at the intersection 52C will be described. did.

On the other hand, in the wiring board 10 according to the first modification, as shown in FIG. 7, the first wiring 521 is located on the insulating layer 30 and the insulating layer 30 is located on the second wiring 522 at the intersection 52C. Is located in.

Similar to the example shown in FIGS. 1 to 5A to 5E, also in the first modification, the dimension A of the insulating layer 30 in the first direction D1 is twice the period F1 of the bellows-shaped portion 57. It is below. As a result, it is possible to suppress the variation in the period F1 of the bellows-shaped portion 57 and prevent the second wiring 522 from being broken or otherwise damaged.

(Second modified example)
Next, a second modification in which the side surface of the insulating layer 30 in the first direction D1 is inclined will be described with reference to FIG. FIG. 8 is a sectional view showing a second modification of the wiring board 10.

In the example shown in FIG. 3, the side surface 30a of the insulating layer 30 in the first direction D1 is parallel to the normal direction of the first surface 21.

On the other hand, in the wiring board 10 in the second modified example, as shown in FIG. 8, the side surface 30a of the insulating layer 30 in the first direction D1 is at least partially in the normal direction of the first surface 21. And is inclined in a direction away from the bellows-shaped portion 57. More specifically, the insulating layer 30 has a dome shape protruding along the normal line direction of the first surface 21, and the side surface 30a is an inclined curved surface inclined in a direction away from the bellows-shaped portion 57.

According to the second modification, the insulating layer 30 can be formed into a smooth shape having no sharp corners of 90° or less. As a result, the shape of the second wiring 522 covering the insulating layer 30 can be made smooth, so that the damage of the second wiring 522 due to the local large stress can be effectively suppressed.

(Third Modification)
Next, a third modification in which the first wiring 521 has a bellows-shaped portion will be described with reference to FIGS. 9 and 10. FIG. 9 is a plan view showing a third modification of the wiring board 10. FIG. 10 is a cross-sectional view showing a case where the wiring board 10 of FIG. 9 is cut along the line XX.

So far, the example in which only the second wiring 522 has the bellows-shaped portion 57 has been described. On the other hand, in the wiring board 10 according to the third modification, as shown in FIG. 10, the first wiring 521 also has the bellows-shaped portion 572.

In the example illustrated in FIG. 9, the first wiring 521 is continuous with the first portion 521a extending in the direction orthogonal to the first direction D1 via the intersection 52C and the first portion 521a, and in the first direction D1. And a stretched second portion 521b. As shown in FIG. 10, the bellows-shaped portion 572 is provided in the second portion 521b of the first wiring 521. Similar to the bellows-shaped portion 57 of the second wiring 522, the bellows-shaped portion 572 of the first wiring 521 includes a plurality of peaks 53 and valleys 55 arranged in the first direction D1. The detailed configuration of the bellows-shaped portion 572 is similar to that of the bellows-shaped portion 57 already described. The bellows-shaped portion 572 can be formed simultaneously with the bellows-shaped portion 57 of the second wiring 522 according to the steps shown in FIGS.

(Fourth Modification)
Next, with reference to FIG. 11, a fourth modification including a stress control layer will be described. FIG. 11 is a sectional view showing a fourth modified example of the wiring board 10.

As shown in FIG. 11, the wiring board 10 according to the fourth modification further includes a stress control layer 7 in addition to the configuration shown in FIG.

The stress control layer 7 is a layer located on the second wiring 522 and controlling the stress acting on the second wiring 522. The stress control layer 7 may control the stress acting on the second wiring 522 by controlling the radius of curvature of the bellows-shaped portion 57. The stress control layer 7 has a bellows shape that follows the bellows shape of the base material 20 and the second wiring 522. The stress control layer 7 can be formed by using the same material as the second wiring 522 and by the same forming method as that of the second wiring 522.

According to the fourth modified example, by suppressing the stress acting on the second wiring 522 by the stress control layer 7, the damage of the second wiring 522 can be effectively suppressed.

(Fifth Modification)
Next, with reference to FIG. 12, a fifth modification including a support substrate will be described. FIG. 12 is a sectional view showing a fifth modified example of the wiring board 10. As shown in FIG. 12, the wiring board 10 in the fifth modified example further includes a support substrate 40 in addition to the configuration of the wiring board 10 in FIG. The support substrate 40 is a plate-shaped member configured to have elasticity lower than that of the base material 20. The support substrate 40 is located between the first surface 21 and the wirings 521 and 522 and supports the wirings 521 and 522. 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 FIG. 12, the support substrate 40 supports the wirings 521 and 522 on the first surface 41 side thereof. The support substrate 40 is joined to the first surface 21 of the base material 20 on the second surface 42 side. For example, as shown in FIG. 12, an adhesive layer 60 containing an adhesive may be provided between the base material 20 and the support substrate 40. As a material forming the adhesive layer 60, for example, an acrylic adhesive, a silicone adhesive, or the like can be used. The thickness of the adhesive layer 60 is, for example, 5 μm or more and 200 μm or less. Although not shown, the second surface 42 of the support substrate 40 may be bonded to the first surface 21 of the base material 20 by a method of molecularly modifying the non-adhesive surface and performing molecular adhesive bonding. In this case, the adhesive layer may not be provided between the base material 20 and the support substrate 40.

The thickness of the support substrate 40 is, for example, 500 nm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less. If the thickness of the support substrate 40 is too small, it becomes difficult to handle the support substrate 40 in the manufacturing process of the support substrate 40 and the process of forming members on the support substrate 40. If the thickness of the support substrate 40 is too large, it becomes difficult to restore the base material 20 when it relaxes, and the target expansion and contraction of the base material 20 cannot be obtained.

As a material forming the support substrate 40, for example, polyethylene naphthalate, polyimide, polyethylene terephthalate, polycarbonate, acrylic resin or the like can be used. Among them, polyethylene naphthalate or polyimide having good durability and heat resistance can be preferably used.

In the example shown in FIGS. 5A to 5E, the first wiring 521, the insulating layer 30, and the second wiring 522 are provided on the base material 20 that is stretched by the tensile stress T. On the other hand, according to the fifth modification, after the first wiring 521, the insulating layer 30, and the second wiring 522 are provided on the support substrate 40 in the non-stretched state, the substrate in the stretched state by the tensile stress T is provided. The support substrate 40 provided with the first wiring 521, the insulating layer 30, and the second wiring 522 is bonded onto the material 20, and then the tensile stress T is removed to obtain the wiring substrate 10 having the bellows-shaped portion 57. be able to.

According to the fifth modification, the wirings 521 and 522 and the insulating layer 30 can be stably mounted on the non-stretched support substrate 40, and thus the wiring substrate 10 having the bellows-shaped portion 57 can be easily manufactured. It is possible to improve the sex.

(Sixth Modification)
Next, referring to FIGS. 13 to 15D, a plurality of modified examples of the planar shape of the insulating layer 30 will be described as a sixth modified example.

So far, the example of the planar rectangular insulating layer 30 having a constant spread in the first direction D1 and the direction orthogonal to the first direction D1 has been described. On the other hand, as shown in FIGS. 13 and 14, the insulating layer 30 may be provided on the first wiring 521 so as to have a linear shape in a plan view. In the example shown in FIG. 13, the size of the insulating layer 30 in the first direction D1 is not more than twice the size of the first wiring 521 in the first direction D1. In addition, the insulating layer 30 may have a circular shape in a plan view as shown in FIG. 15A, or may have a triangular shape in a plan view as shown in FIG. 15B, and As shown in FIG. 15C, it may have a rectangular shape with rounded corners in a plan view. Further, as shown in FIG. 15D, the side surface 30a of the insulating layer 30 in the first direction D1 may have a shape along the bellows-shaped portion 27 in a plan view. Note that, in FIG. 15D, the planar shapes of the peaks and the peaks of the valleys of the bellows-shaped portion 57 in the vicinity of the insulating layer 30 are schematically shown by alternate long and short dash lines. In the example illustrated in FIG. 15D, the bellows-shaped portion 57 near the insulating layer 30 has a substantially arc shape that is convex toward the insulating layer 30 side in a plan view, and is a side surface of the insulating layer 30 in the first direction D1. 30a has a substantially arc shape that follows the shape of the bellows-shaped portion 57.

As shown in FIG. 15D, by forming the side surface 30a of the insulating layer 30 along the bellows-shaped portion 57, it is possible to prevent a large stress from being locally applied to the second wiring 522 in the vicinity of the insulating layer 30. You can As a result, damage to the second wiring 522 can be effectively suppressed.

(Seventh Modification)
Next, with reference to FIG. 16, a seventh modification in which the dimension between the one end and the other end of the connection portion of the electronic component is set to be twice the cycle of the bellows-shaped portion or less will be described. FIG. 16 is a sectional view showing a seventh modified example of the wiring board 10.

As shown in FIG. 16, the wiring substrate 10 in the seventh modified example has a stretchable base material 20, wirings 52 located on the first surface 21 of the base material 20, and the first surface 21 side. , The electronic component 51 connected to the wiring 52. The wiring 52 has a bellows-shaped portion 57 including a plurality of peaks 53 and valleys 55 arranged along the first direction D1. The configurations of the wiring 52 and the bellows-shaped portion 57 are the same as the configurations of the second wiring 522 and the bellows-shaped portion 57 of the second wiring 522 described above, and thus detailed description thereof will be omitted.

The electronic component 51 is electrically connected to the wiring 52 via the conductive connecting portion 51a. The connection portion 51a may be solder, a conductive adhesive, or the like. Further, as shown in FIG. 16, two connecting portions 51a are present so that each of the two wirings 52, 52 provided at intervals in the first direction D1 can be connected to the electronic component 51. Good. The electronic component 51 may be an active component, a passive component, or a mechanical component.

Examples of the electronic component 51 include transistors, LSIs (Large-Scale Integration), MEMSs (Micro Electro Mechanical Systems), relays, light emitting devices such as LEDs, OLEDs, LCDs, sounding components such as sensors and buzzers, and vibrations that generate vibrations. Examples include components, Peltier elements for controlling cooling heat generation, cold heat generating components such as heating wires, resistors, capacitors, inductors, piezoelectric elements, switches, connectors, and the like. Of the above examples of the electronic component 51, the sensor is preferably used. As the sensor, for example, a temperature sensor, a pressure sensor, an optical sensor, a photoelectric sensor, a proximity sensor, a shear force sensor, a biological sensor, a laser sensor, a microwave sensor, a humidity sensor, a strain sensor, a gyro sensor, an acceleration sensor, a displacement sensor, Examples thereof include magnetic sensors, gas sensors, GPS sensors, ultrasonic sensors, odor sensors, brain wave sensors, current sensors, vibration sensors, pulse wave sensors, electrocardiographic sensors, and luminous intensity sensors. Of these sensors, biosensors are particularly preferred. The biometric sensor can measure biometric information such as heartbeat, pulse rate, electrocardiogram, blood pressure, body temperature, and blood oxygen concentration.

Since the electronic component 51 has a predetermined thickness, dimensions and rigidity in the first direction D1 at a position adjacent to the bellows-shaped portion 57, the cycle of the bellows-shaped portion 57 can be affected. If the dimension between the one end and the other end of the connecting portion 51a in the first direction D1 is larger than twice the period F1 of the bellows-shaped portion 57, the period F1 of the bellows-shaped portion 57 varies, and thus the wiring 52 It may be broken or broken.

On the other hand, the dimension B between the one end and the other end of the connecting portion 51a in the first direction D1 in the seventh modified example is not more than twice the cycle F1 of the bellows-shaped portion 57. In the example shown in FIG. 16, the dimension B is the left end of the first connecting portion 51a that is located on the left side of the plurality of connecting portions 51a, and the right side of the plurality of connecting portions 51a. Is a dimension B between the right end portion of the second connecting portion 51a and the second connecting portion 51a. In this way, by setting the dimension B to be equal to or less than twice the period F1 of the bellows-shaped portion 57, it is possible to suppress the variation of the period F1 of the bellows-shaped portion 57. By suppressing the variation of the period F1 of the bellows-shaped portion 57, it is possible to prevent the wiring 52 from being broken or otherwise damaged.

The dimension B between one end and the other end of the connecting portion 51a in the first direction D1 is more preferably 0.01 times or more and 2 times or less, and 0.2 times or more and 1 times or more, the period F1 of the bellows shape portion 57. It is even more preferably 0.0 times or less.

Hereinafter, with reference to FIGS. 17A to 17D, a method of manufacturing the wiring board 10 according to the seventh modification will be described.

First, as shown in FIG. 17A, a base material preparing step of preparing a base material 20 having elasticity is performed. Subsequently, as shown in FIG. 17B, a stretching step of stretching the substrate 20 by applying tensile stress T to the substrate 20 is performed.

After carrying out the stretching step, as shown in FIG. 17B, a wiring step is carried out in which the wiring 52 is provided on the first surface 21 of the base material 20 which is stretched by the tensile stress T.

After performing the wiring step, as shown in FIG. 17C, a component connecting step of connecting the electronic component 51 to the wiring 52 via the connecting portion 51a is performed. In the component connecting process, the dimension B between the one end and the other end in the first direction D1 is equal to or less than twice the cycle F1 of the bellows-shaped portion 57 formed in the contracting process described later. Connect the parts 51. The dimension B between the one end and the other end in the first direction D1 of the connecting portion 51a, which is equal to or less than twice the period F1 of the bellows-shaped portion 57, can be acquired in advance by simulation or experiment.

After the component connecting step is performed, a shrinking step for removing the tensile stress from the base material 20 is performed as shown in FIG. As a result, as shown by the arrow C in FIG. 17D, the base material 20 contracts, and the wiring 52 provided on the base material 20 is also deformed. As a result, the bellows-shaped portion 57 having a period F1 that is ½ or more of the dimension B between one end and the other end of the connection portion 51a in the first direction D1 is formed on the wiring 52.

In the seventh modification, the dimension B between the one end and the other end of the connecting portion 51a in the first direction D1 is not more than twice the cycle F1 of the bellows-shaped portion 57. As a result, it is possible to suppress the variation in the period F1 of the bellows-shaped portion 57 and prevent the wiring 52 from being broken or otherwise damaged.

(Eighth modification)
Next, with reference to FIG. 18, an eighth modification will be described in which the dimension between one end and the other end of the sealing material that seals the electronic component is set to be twice the cycle of the bellows-shaped portion or less. FIG. 18 is a sectional view showing an eighth modified example of the wiring board 10.

As shown in FIG. 18, the wiring board 10 in the eighth modified example further includes a potting material 8 which is an example of a sealing material in addition to the configuration of FIG. The potting material 8 is located on the electronic component 51 or the wiring 52 and seals the electronic component 51. As shown in FIG. 18, the potting material 8 is provided on the electronic component 51 in a state of spreading outside the electronic component 51 in the first direction D1. In the example shown in FIG. 18, the potting material 8 has a dome shape. As the potting material 8, for example, a resin such as an epoxy resin or a urethane resin may be adopted.

Since the potting material 8 has a predetermined thickness, a dimension and rigidity in the first direction D1 at a position adjacent to the bellows-shaped portion 57, it can affect the cycle of the bellows-shaped portion 57. If the dimension between the one end and the other end of the potting material 8 in the first direction D1 is larger than twice the period F1 of the bellows-shaped portion 57, the period F1 of the bellows-shaped portion 57 varies, and thus the wiring 52 It may be broken or broken.

On the other hand, the dimension B between the one end and the other end in the first direction D1 of the potting material 8 in the eighth modification is less than or equal to twice the cycle F1 of the bellows-shaped portion 57. In this way, by setting the dimension B to be equal to or less than twice the period F1 of the bellows-shaped portion 57, it is possible to suppress the variation of the period F1 of the bellows-shaped portion 57. By suppressing the variation of the period F1 of the bellows-shaped portion 57, it is possible to prevent the wiring 52 from being broken or otherwise damaged.

The dimension B between the one end and the other end of the potting material 8 in the first direction D1 is more preferably 0.01 times or more and 2 times or less of the cycle F1 of the bellows shape portion 57, and 0.2 times or more 1 It is even more preferably 0.0 times or less.

Similar to the insulating layer 30 shown in FIGS. 6A and 6B, when the tensile stress T is removed and the substrate 20 contracts, the first direction is adjusted according to the wave of the bellows-shaped portion 57. When the potting material 8 is deformed on the end side of D1, the dimension B between the one end and the other end of the potting material 8 in the first direction D1 is in the first direction D1 which hardly deforms when the substrate 20 contracts. It may be defined as the dimension B of the potting material 8 on the center side. The dimension B of the potting material 8 on the central side in the first direction D1 is 50% to 100% of the dimension of the potting material 8 on the central side in the first direction D1 with respect to the dimension of the potting material 8 in the entire range in the first direction D1. It becomes a dimension.

Hereinafter, with reference to FIGS. 19A to 19E, a method of manufacturing the wiring board 10 according to the eighth modification will be described.

First, as shown in FIG. 19A, a base material preparing step of preparing a base material 20 having elasticity is performed. Subsequently, as shown in FIG. 19B, a stretching step of stretching the substrate 20 by applying a tensile stress T to the substrate 20 is performed. After the extension step is performed, as shown in FIG. 19B, the wiring step is performed in which the wiring 52 is provided on the first surface 21 of the base material 20 which is extended by the tensile stress T. After the wiring step is performed, as shown in FIG. 19C, the component connection step of connecting the electronic component 51 to the wiring 52 via the connection portion 51a is performed.

After performing the component connecting step, as shown in FIG. 19D, a sealing step of sealing the electronic component 51 by potting is performed. In the sealing step, the potting material 8 having the dimension B between the one end and the other end in the first direction D1 which is equal to or less than twice the cycle F1 of the bellows-shaped portion 57 formed in the shrinking step described later is used as the electronic component 51. The electronic component 51 is sealed by forming it above. The dimension B between the one end and the other end in the first direction D1 of the potting material 8 that is not more than twice the cycle F1 of the bellows-shaped portion 57 can be acquired in advance by simulation or experiment.

After performing the sealing step, as shown in FIG. 19E, a shrinking step for removing the tensile stress from the base material 20 is performed. As a result, as shown by the arrow C in FIG. 19E, the base material 20 contracts, and the wiring 52 provided on the base material 20 is also deformed. As a result, the wiring 52 is formed with the bellows-shaped portion 57 having a period F1 that is ½ or more of the dimension B between one end and the other end of the potting material 8 in the first direction D1.

In the eighth modification, the dimension B between the one end and the other end of the potting material 8 in the first direction D1 is not more than twice the cycle F1 of the bellows-shaped portion 57. As a result, it is possible to suppress the variation in the period F1 of the bellows-shaped portion 57 and prevent the wiring 52 from being broken or otherwise damaged.

(Ninth Modification)
Next, with reference to FIG. 20, a ninth modification having a bellows-shaped portion along the first direction and a bellows-shaped portion along a direction orthogonal to the first direction will be described.

So far, the example of the wiring board 10 including the second wiring 522 having the bellows-shaped portion 57 along the first direction D1 has been described. On the other hand, in the wiring board 10 according to the ninth modification, as shown in FIG. 20, in addition to the second wiring 522 having the bellows-shaped portion 57, the first wiring 521 is arranged in the first direction D1. It has a bellows-shaped portion 573 along the orthogonal direction. In FIG. 20, the peaks and the peaks of the valleys of the bellows-shaped portions 57 and 573 are indicated by alternate long and short dash lines. Such a wiring board 10 includes a step of applying tensile stress to the base material 20 in a direction orthogonal to the first direction D1 in the extending step shown in FIG. 5B, and FIG. It can be formed by including the step of removing the tensile stress in the direction orthogonal to the first direction D1 in the contraction step shown in FIG.

Further, other than the above, the intersecting portions 52C or the small electronic components 51 formed on the wiring may be arranged periodically. By arranging them periodically, it is possible to prevent the cycle of the bellows-shaped portion 57 from being disturbed over the entire area of the wiring, so that the expansion/contraction durability can be improved.

Next, the present disclosure will be described more specifically by way of examples, but the present disclosure is not limited to the description of the examples below as long as the gist thereof is not exceeded.

(First embodiment)
As shown in FIG. 21, in the first embodiment, a base material 20, an adhesive layer 60, a support substrate 40, a first wiring 521, an insulating layer 30, a second wiring 522 and a second insulating layer 9 are provided in this order. The wiring board 10 was produced. Hereinafter, a method of manufacturing the wiring board 10 will be described.

<<Preparation of substrate and adhesive layer>>
A pressure-sensitive adhesive sheet 8146 (manufactured by 3M) is used as the adhesive layer 60, and polydimethylsiloxane (PDMS) of 2-liquid addition condensation is applied on the pressure-sensitive adhesive sheet so as to have a thickness of 1.5 mm, and the PDMS is cured. A laminate of 60 and the substrate 20 was prepared. Subsequently, a part of the laminated body was taken out as a sample, and the elastic modulus of the base material 20 was measured by a tensile test based on JIS K6251. As a result, the elastic modulus of the base material 20 was 0.05 MPa.

<<Preparation of supporting substrate, wiring, and insulating layer>>
A polyethylene naphthalate (PEN) film having a thickness of 1 μm is used as the supporting substrate 40, a Cu film having a thickness of 1 μm is formed on the supporting substrate 40 made of a PEN film by a vapor deposition method, and the Cu film is patterned by a photolithography method. By doing so, the first wiring 521 having a wiring width of 200 μm was formed. Subsequently, a dome-shaped thermosetting insulating polymer having a thickness of 20 μm is formed by screen printing at a position where the intersecting portion 52C is formed on the first wiring 521, and the thermosetting insulating polymer is heated and cured. Then, the insulating layer 30 having a dimension of 300 μm in the first direction D1 was formed. Subsequently, a Cu film having a thickness of 1 μm is formed on the insulating layer 30 or the supporting substrate 40 by a vapor deposition method, and the Cu film is patterned by a photolithography method to form a second wiring 522 having a wiring width of 200 μm. did. Subsequently, a thermosetting insulating polymer having a thickness of 10 μm was entirely formed on the supporting substrate 40 by screen printing, and the thermosetting insulating polymer was heated and cured to form the second insulating layer 9. ..

<< Fabrication of wiring board >>
With the laminate of the adhesive layer 60 and the base material 20 prepared above stretched uniaxially 50% along the first direction D1, the support substrate 40 prepared above is attached to the adhesive layer 60. It was Next, the laminate of the adhesive layer 60 and the base material 20 was contracted by releasing the extension. As a result, an uneven shape was generated and contracted on the surface of the support substrate 40 along the first direction D1. At this time, the average period of the uneven shape, that is, the bellows-shaped portion was 500 μm.

In the wiring board 10 of the first example thus manufactured, the first wiring 521 and the second wiring 522 were not broken even after the expansion of 30% for 100,000 times.

(Second embodiment)
The second embodiment differs from the first embodiment only in that the dimension of the insulating layer 30 in the first direction D1 is 500 μm. In the wiring board 10 according to the second embodiment, the first wiring 521 and the second wiring 522 were not broken even when the expansion of 30% was performed 100,000 times.

(Third embodiment)
The third embodiment differs from the first embodiment only in that the dimension of the insulating layer 30 in the first direction D1 is 600 μm. In the wiring board 10 according to the third embodiment, the first wiring 521 and the second wiring 522 were not broken even after the expansion of 30% was performed 100,000 times.

(First Comparative Example)
The first comparative example differs from the first comparative example only in that the dimension of the insulating layer 30 in the first direction D1 is 800 μm. In the wiring board 10 in the first comparative example, disconnection occurred in the first wiring 521 and the second wiring 522 when the expansion of 30% was performed 60,000 times.

(Fourth embodiment)
As shown in FIG. 22, in the fourth example, the wiring substrate 10 including the base material 20, the adhesive layer 60, the support substrate 40, the wiring 52, the insulating layer 11, and the electronic component 51 was manufactured in order. Hereinafter, a method of manufacturing the wiring board 10 according to the fourth embodiment will be described with a focus on differences from the first embodiment.

In the fourth embodiment, a polyethylene naphthalate (PEN) film having a thickness of 1 μm and an elastic coefficient of 2.2 Gpa is used as the supporting substrate 40, and a film having a thickness of 1 μm is formed on the supporting substrate 40 made of a PEN film by a vapor deposition method. By forming a Cu film and patterning the Cu film by a photolithography method, six wirings 52 having a wiring width of 200 μm and a wiring interval of 400 μm were formed. Subsequently, a thermosetting insulating polymer having a thickness of 10 μm is formed on the wiring 52 by screen printing so that an end portion of the wiring 52 is exposed, and the thermosetting insulating polymer is heated and cured to form an insulating layer. 11 was formed. Subsequently, a conductive adhesive (CL-3160 manufactured by Kaken Tech Co., Ltd.) was formed as a connecting portion 51a on the end portion of the wiring 52 exposed from the insulating layer 11 by screen printing. Then, the electronic component 51 was mounted on the connection part 51a made of a conductive adhesive material by a mounter. The size of the electronic component 51 was 200 μm in the first direction D1 and 400 μm in the direction orthogonal to the first direction D1. Note that the dimension of the electronic component 51 in the first direction D1 was the dimension between one end and the other end of the connecting portion 51a in the first direction D1 as indicated by the symbol B in FIG.

Then, the laminate of the adhesive layer 60 and the base material 20 prepared by the same method as in the first embodiment is uniaxially stretched by 50% along the first direction D1, and The supporting substrate 40 prepared as described above was attached. Then, the laminate of the adhesive layer 60 and the base material 20 was contracted by releasing the extension. As a result, an uneven shape was generated on the surface of the support substrate 40 along the first direction D1 and contracted. At this time, the average of the periods of the uneven shape, that is, the bellows-shaped portion was 500 μm.

In the wiring board 10 according to the fourth example thus manufactured, the wiring 52 did not break even after the elongation of 30% was performed 100,000 times.

(Fifth embodiment)
The fifth embodiment is different from the fourth embodiment only in that the dimension B of the electronic component 51 in the first direction D1 is 400 μm, and the dimension of the electronic component 51 in the direction orthogonal to the first direction D1 is 200 μm. Is different. In the wiring board 10 according to the fourth example, the wiring 52 did not break even after being stretched 30% 100,000 times.

(Sixth embodiment)
The sixth embodiment is different from the fourth embodiment only in that the dimension B of the electronic component 51 in the first direction D1 is 500 μm and the dimension of the electronic component 51 in the direction orthogonal to the first direction D1 is 1000 μm. Is different. In the wiring board 10 according to the sixth example, the wiring 52 did not break even after being stretched 30% 100,000 times.

(Second Comparative Example)
The second comparative example is different from the fourth embodiment only in that the dimension B of the electronic component 51 in the first direction D1 is 800 μm, and the dimension of the electronic component 51 in the direction orthogonal to the first direction D1 is 400 μm. Is different. In the wiring board 10 in the second comparative example, the wiring 52 was broken when the elongation of 30% was performed 60,000 times.

It should be noted that although some modified examples of the above-described embodiment have been described, naturally, it is also possible to appropriately combine and apply a plurality of modified examples.

10 wiring board 20 base material 21 first surface 22 second surface 30 insulating layer 30a side surface 521 first wiring 522 second wiring 52 wiring 53, 54 peaks 55, 56 trough 57 bellows shaped portion 572 second bellows shaped portion 7 Stress control layer

Claims (17)

A stretchable base material,
A first wiring located on the first surface side of the base material;
A plurality of mountain portions that are second wirings located on the side of the first surface and that intersect with the first wirings in a plan view and are arranged along a first direction that is one of in-plane directions of the first surface. And a second wiring having a bellows-shaped portion including a valley portion,
An insulating layer located between the first wiring and the second wiring at an intersection of the first wiring and the second wiring and insulating the first wiring and the second wiring;
The wiring board in which the dimension of the insulating layer in the first direction is equal to or less than twice the cycle of the bellows-shaped portion. The wiring board according to claim 1, wherein, at the intersection, the second wiring is located on the insulating layer, and the insulating layer is located on the first wiring. The wiring board according to claim 2, further comprising a stress control layer located on the second wiring and controlling a stress acting on the second wiring. The side surface of the insulating layer in the first direction is at least partially inclined in a direction away from the bellows-shaped portion with respect to a normal direction of the first surface. The wiring board described in. The wiring board according to claim 4, wherein the insulating layer has a dome shape protruding along a direction normal to the first surface. The wiring board according to claim 1, wherein at the intersection, the first wiring is located on the insulating layer, and the insulating layer is located on the second wiring. The wiring board according to any one of claims 1 to 6, wherein the first wiring has a second bellows-shaped portion including a plurality of peaks and valleys arranged along the first direction. The wiring board according to claim 1, wherein the insulating layer has a bending rigidity higher than that of the base material. The wiring board according to claim 1, wherein the insulating layer has an elastic coefficient larger than that of the base material. A stretchable base material,
The wiring is located on the first surface side of the base material and has a bellows-shaped portion including a plurality of peaks and valleys arranged along a first direction which is one of in-plane directions of the first surface. Wiring,
An electronic component located on the first surface side and connected to the wiring through a connecting portion,
The wiring board in which the dimension between the one end and the other end of the connection portion in the first direction is equal to or less than twice the cycle of the bellows-shaped portion. A stretchable base material,
The wiring is located on the first surface side of the base material and has a bellows-shaped portion including a plurality of peaks and valleys arranged along a first direction which is one of in-plane directions of the first surface. Wiring,
An electronic component located on the first surface side and connected to the wiring;
A sealing material which is located on the electronic component and seals the electronic component,
The wiring substrate, wherein the dimension between the one end and the other end of the sealing material in the first direction is equal to or less than twice the cycle of the bellows-shaped portion. The wiring board according to claim 1, wherein the bellows-shaped portion has an amplitude of 1 μm or more. The amplitude of the peaks and valleys that appear in the portion of the second surface of the base material that is located opposite to the first surface that overlaps the bellows-shaped portion is the bellows shape of the first surface of the base material. The wiring board according to any one of claims 1 to 12, which has a smaller amplitude than a peak portion and a valley portion that appear in a portion overlapping the portion. The amplitude of the peaks and valleys that appear in the portion of the second surface of the base material that is located opposite to the first surface that overlaps the bellows-shaped portion is the bellows shape of the first surface of the base material. 14. The wiring board according to claim 13, wherein the amplitude is 0.9 times or less of the amplitude of the peaks and valleys that appear in the portion overlapping the portion. A stretching step of stretching the substrate by applying tensile stress to the substrate having elasticity.
A first wiring step of providing a first wiring on the first surface side of the base material in the stretched state;
A second wiring step of providing a second wiring on the first surface side of the base material so as to intersect the first wiring in a plan view;
Insulation provided with an insulating layer that insulates the first wiring and the second wiring so as to be located between the first wiring and the second wiring at the intersection of the first wiring and the second wiring Process,
A shrinking step for removing the tensile stress from the base material,
After the tensile stress is removed from the base material, the second wiring has a plurality of peaks and valleys arranged along a first direction which is one of in-plane directions of the first surface of the base material. Has a bellows-shaped portion including
The method of manufacturing a wiring board, wherein the dimension of the insulating layer in the first direction is equal to or less than twice the cycle of the bellows-shaped portion. A stretching step of stretching the substrate by applying tensile stress to the substrate having elasticity.
A wiring step of providing wiring on the first surface side of the base material in the stretched state,
A component connecting step of connecting an electronic component to the wiring through a connecting portion,
A shrinking step for removing the tensile stress from the base material,
After the tensile stress is removed from the base material, the wiring includes a plurality of peaks and valleys arranged along a first direction which is one of in-plane directions of the first surface of the base material. It has a bellows shape part,
The method for manufacturing a wiring board, wherein a dimension between one end and the other end of the connection portion in the first direction is equal to or less than twice the cycle of the bellows-shaped portion. A stretching step of stretching the substrate by applying tensile stress to the substrate having elasticity.
A wiring step of providing wiring on the first surface side of the base material in the stretched state,
A component connecting step of connecting an electronic component to the wiring,
A sealing step of sealing the electronic component with a sealing material,
A shrinking step for removing the tensile stress from the base material,
After the tensile stress is removed from the base material, the wiring includes a plurality of peaks and valleys arranged along a first direction which is one of in-plane directions of the first surface of the base material. It has a bellows shape part,
The method for manufacturing a wiring board, wherein a dimension between one end and the other end of the sealing material in the first direction is equal to or less than twice the cycle of the bellows-shaped portion.