WO2020262288A1 - Stretchable circuit board and stretchable circuit assembly - Google Patents

Abstract

One aspect of the present invention is a stretchable circuit board comprising a stretchable insulation layer and stretchable wiring provided on the stretchable insulation layer, wherein: the stretchable insulation layer has an opening at a position that is electrically insulated from the stretchable wiring; and a breathable ventilation hole is formed in the through-thickness direction of the stretchable insulation layer.

Description

Elastic circuit board and elastic circuit mounting product

The present invention relates to an elastic circuit board and an elastic circuit mounted product.

With the development of the electronics field, there are increasing demands for miniaturization, thinning, weight reduction, and high density of electronic devices and the like. Further, depending on the application, a flexible device that can be freely deformed or bent may be required in order to arrange it on a curved surface, an uneven surface, or the like. Such flexible devices include, for example, wearable devices that can be worn on animals such as humans and dogs, and plants, and various interfaces such as displays, sensors, and artificial skin for robots used for digital signage and the like. Examples include devices and conductive materials used. As a circuit board provided in a wearable device, digital signage, etc., elasticity is required. In particular, in the case of wearable devices worn by humans and animals, elasticity that can follow the movement of the body is required. Examples of the elastic circuit board include the wiring boards described in Patent Document 1 and Patent Document 2.

Patent Document 1 includes a plurality of elastic base materials and a plurality of elastic wiring portions provided on each of the facing main surfaces of the plurality of elastic base materials, and each of the main surfaces thereof. Described is an elastic wiring board in which the elastic wiring portions provided in the above are electrically connected to each other via a connection portion. Further, in Patent Document 1, in the elastic wiring board, a plurality of the elastic base materials include a first elastic base material and a second elastic base material, and the first elastic base material is the first. The first stretchable wiring portion formed on the opening and the first main surface is provided, and the second stretchable base material is the second stretchable wiring portion formed on the second opening and the second main surface. A wiring portion is provided, the first main surface and the second main surface face each other, and at least a part of the first opening and the second elastic wiring portion overlap, and the second opening and the first It is described that at least a part of one elastic wiring portion overlaps.

Patent Document 2 describes a wiring board having a stretchable resin layer, a conductor foil provided on the stretchable resin layer and forming a wiring pattern, and a via hole provided on the stretchable resin layer. Has been done.

According to Patent Document 1, it is disclosed that multi-layering is possible while preventing disconnection due to elongation. Further, according to Patent Document 2, it is disclosed that it has high elasticity and can be interconnected between layers at the time of lamination.

JP-A-2017-152687 International Publication No. 2018/123732

An object of the present invention is to provide an elastic circuit board and an elastic circuit mount product having excellent breathability.

One aspect of the present invention includes an elastic insulating layer and elastic wiring provided on at least one of the surface and the inside of the elastic insulating layer, and the elastic insulating layer is formed from the elastic wiring. The stretchable circuit board is characterized in that it has an opening at an electrically insulated position and a vent hole that allows ventilation in the thickness direction of the stretchable insulating layer is formed.

FIG. 1 is a perspective view showing an example of an elastic circuit board according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the elastic circuit board shown in FIG. 1 as viewed from the cut plane lines II-II. FIG. 3A is a diagram showing an example of the shape of the opening of the ventilation hole (state in which the stretchable circuit board is not stretched) in the stretchable circuit board according to the embodiment of the present invention. FIG. 3B is a diagram showing an example of an opening state (a state in which the stretchable circuit board is extended in the X-axis direction) of the opening of the ventilation hole in the stretchable circuit board according to the embodiment of the present invention. FIG. 3C is a diagram showing an example of an open state (a state in which the stretchable circuit board is extended in the Y-axis direction) of the opening of the ventilation hole in the stretchable circuit board according to the embodiment of the present invention. FIG. 3D is a diagram for explaining the shape of the opening of the ventilation hole in the stretchable circuit board according to the embodiment of the present invention and the change in the opening state of the opening due to the expansion and contraction of the stretchable circuit board. FIG. 3E is a diagram for explaining the shape of the opening of the ventilation hole in the stretchable circuit board according to the embodiment of the present invention and the change in the opening state of the opening due to the expansion and contraction of the stretchable circuit board. FIG. 3F is a diagram for explaining the shape of the opening of the ventilation hole in the stretchable circuit board according to the embodiment of the present invention and the change in the opening state of the opening due to the expansion and contraction of the stretchable circuit board. FIG. 4 is a diagram showing another example of the shape of the opening of the vent in the elastic circuit board according to the embodiment of the present invention. FIG. 5 is a cross-sectional view showing another example of the stretchable circuit board according to the embodiment of the present invention. FIG. 6 is an enlarged cross-sectional view showing a part A of the stretchable circuit board shown in FIG. FIG. 7 is a cross-sectional view showing another example of the stretchable circuit board according to the embodiment of the present invention. FIG. 8 is an enlarged cross-sectional view showing a part A of the stretchable circuit board shown in FIG. 7. FIG. 9 is a diagram for explaining a convex portion in the stretchable circuit board according to the embodiment of the present invention. FIG. 10 is a diagram for explaining elastic wiring in the elastic circuit board according to the embodiment of the present invention.

Among wearable devices, wearable devices that are worn by humans and animals are used in contact with or close to the body, such as by attaching them to clothes or the body. For this reason, when the wearable device is used in a state of being attached to clothes or the like, it is required to be comfortable to wear, and when the wearable device is directly attached to the body and used, the wearing feeling of the wearable device is required. Is required to be good. From these facts, it is required that the circuit board provided in the wearable device can also improve the comfort and wearing feeling of the wearable device.

According to the study by the present inventors, even if the conventional circuit board has elasticity and can follow the movement of the body, the wearable device equipped with the same does not have good comfort and wearing feeling. There was a case. Specifically, in a wearable device provided with a conventional circuit board, discomfort due to sweat may occur. It is presumed that this is because, for example, in the conventional wiring boards and the like described in Patent Document 1 and Patent Document 2, it is difficult for moisture such as sweat to permeate because it has not been studied to improve the air permeability.

Further, when such a circuit board is used in a wearable device, water and oil such as sweat as described above may fill the periphery of the wearable device worn by a person or a plant. This may cause a failure or malfunction of the electronic components mounted on the circuit board.

On the other hand, in the conventional wiring boards and the like described in Patent Document 1 and Patent Document 2, for example, holes such as vias for interlayer connection may be formed. However, this hole is for interlayerly connecting a conductor electrically connected to an electronic component mounted on a circuit board or the like, and does not take air permeability into consideration. Therefore, even in a multi-layered substrate, air permeability could not be ensured.

The present inventors presumed that the circuit board provided in the wearable device is required to have air permeability in order to suppress the occurrence of the above-mentioned problems.

In addition, large-screen digital signage, etc. are required to be hard to break due to the wind. In order to realize this, the circuit board provided in the digital signage or the like has air permeability similar to the circuit board provided in the wearable device so that the wind or the like hitting the digital signage or the like can pass through. I guessed that it would be required.

As a result of various studies, the present inventors have found that the following objects, such as providing a stretchable circuit board and a stretchable circuit mounted product having excellent breathability, can be achieved by the following invention.

Hereinafter, embodiments according to the present invention will be described, but the present invention is not limited thereto. In the present specification and the drawings, substantially the same components may be designated by the same reference numerals to omit duplicate description. Further, in the following description and drawings, it is assumed that the stretchable circuit board is arranged on the XY plane, and the Z-axis direction (vertical direction) orthogonal to the XY plane is the vertical direction.

As shown in FIGS. 1 and 2, the stretchable circuit board 1 according to the embodiment of the present invention is provided on at least one of the stretchable insulating layer 11 and the surface and the inside of the stretchable insulating layer 11. It is provided with a sex wiring 12. The stretchable insulating layer 11 has an opening at a position electrically insulated from the stretchable wiring 12, and is in the thickness direction of the stretchable insulating layer 11 (Z-axis direction in FIGS. 1 and 2). A vent hole 13 that allows ventilation is formed in the air. That is, the ventilation hole 13 is a passage that penetrates from the opening formed on one surface of the elastic insulating layer 11 to the opening formed on the other surface, and both of the openings are open. The ventilation holes 13 are electrically insulated from the elastic wiring 12. The position where the ventilation hole 13 is formed is preferably a position where the stretchable insulating layer 11 does not overlap with the stretchable wiring 12, that is, a position where the stretchable wiring 12 is not formed in a plan view. Although vias for interlayer connection can be formed in the elastic insulating layer 11 as needed, the vias are electrically connected to the elastic insulating layer 11, whereas the ventilation holes 13 are provided. It can be distinguished by being electrically insulated from the elastic wiring 12. Further, by mounting the electronic component 14 on the stretchable circuit board 1, the stretchable circuit mounted product 100 can be obtained. In the stretchable circuit mounting product 100, the electronic component 14 is connected to the stretchable wiring 12.

The stretchable circuit board 1 and the stretchable circuit mounting product 100 can, for example, move moisture (moisture) existing on one surface side to the other surface side through the ventilation holes 13. That is, in the stretchable circuit board 1 and the stretchable circuit mounted product 100, since the ventilation holes 13 can allow moisture to escape, the stretchable circuit board 1 is excellent in breathability, and it is possible to prevent the moisture from remaining on one surface.

Therefore, the stretchable circuit board 1 and the stretchable circuit mounting product 100 are applied to a wearable device used by being adhered to an object, particularly a patch device used by being directly attached to a human living body or attached to clothes or the like. It is highly useful because it can dissipate water such as sweat.

Further, for example, when a light emitting sheet provided with an LED element or the like on the elastic circuit board according to the present embodiment is used for a display device such as a huge digital signage used in a stadium or the like, such a communication is used. The presence of pores also has the advantage of being able to prevent breakage and wind fanning. The vents also contribute to cooling the LED element.

[Definition of elasticity]
The stretchable insulating layer 11, the stretchable wiring 12, the stretchable circuit board 1, and the stretchable circuit mount product 100 in the present embodiment each have elasticity. Here, "having elasticity" means that it can be elastically deformed, and more specifically, it has an elongation rate of 10% or more and a tensile elastic modulus at room temperature of 25 ° C. of 0.5 to. It means that it is 500 MPa.

The elongation rate is 10% or more, preferably 25% or more, more preferably 50% or more, and even more preferably 100% or more. Further, the higher the elongation rate is, the more preferable it is, but it is preferably 500% or less from the viewpoint that when it is stretched more than necessary, plastic deformation tends to occur and the original shape tends to be impaired. The tensile elastic modulus at room temperature at 25 ° C. is 0.5 to 500 MPa, preferably 1 to 300 MPa, more preferably 2 to 200 MPa, and even more preferably 5 to 100 MPa. When the elongation rate and the tensile elastic modulus are within the above ranges, it is easily deformed into an arbitrary shape. For example, when the stretchable circuit board is attached to clothes or the like, it is excellent in followability to the deformation of clothes. The tensile elastic modulus refers to the storage elastic modulus at 25 ° C. measured by performing a temperature-dependent measurement in a tensile test using a dynamic viscoelasticity measuring device. Examples of the dynamic viscoelasticity measuring device include DMS6100 manufactured by Seiko Instruments Inc.

[Structural features]
As shown in FIGS. 1 and 2, the ventilation hole 13 is a passage that penetrates from the opening formed on one surface of the elastic insulating layer 11 to the opening formed on the other surface, and is elastic. It is provided at a position that does not overlap with the wiring 12. The number of ventilation holes 13 formed in the elastic insulating layer 11 is not particularly limited, but from the viewpoint of improving air permeability, a plurality of ventilation holes 13 are formed in the elastic insulating layer 11 as shown in FIGS. 3A to 3F. It is preferably formed.

The shape of the opening is preferably a shape that does not easily break when the elastic insulating layer 11 is expanded and contracted in the plane direction (the direction of the arrows indicated by X and Y in FIGS. 1 and 2), and is further closed. It is preferable that the shape is difficult (it is easy to maintain a wide open state). Examples of the shape of such an opening (the shape of the elastic insulating layer 11 in the plane direction) include a circular shape, an elliptical shape, and a polygonal shape. When a plurality of ventilation holes 13 are formed, the shapes of the openings in the respective ventilation holes may be the same shape, or may be a combination of different shapes. Specifically, as the stretchable circuit board 1 and the stretchable circuit mounting product 100, as shown in FIGS. 3A to 3F, a plurality of openings having various shapes are formed in the stretchable insulating layer 11. Examples include the sex circuit board 1 and the stretchable circuit mounted product 100. Note that FIGS. 3A to 3F show only the elastic insulating layer 11 and the ventilation holes 13, and the elastic wiring and the like are omitted. 3A to 3F show an example of the ventilation hole 13 in which the shape of the opening is circular (shape 13-1), elliptical (shape 13-2), and polygonal (shape 13-3). ing.

FIG. 3A shows a state in which the stretchable circuit board 1 is not stretched. FIG. 3B shows a state in which the stretchable circuit board 1 is extended in the X-axis direction. FIG. 3C shows a state in which the stretchable circuit board 1 is extended in the Y-axis direction. As shown in FIGS. 3A to 3C, when the stretchable circuit board 1 is expanded and contracted in the X-axis direction and the Y-axis direction, the openings of some of the ventilation holes 13 are almost completely closed. It can be seen that the opening of the other vent hole 13 is maintained in a wide open state. In the present embodiment, the shape of the opening is the shape of the opening in a state where no stress for expanding and contracting the stretchable circuit board is particularly applied (for example, the state of FIG. 3A). is there.

[Change in opening state due to expansion and contraction of the shape and elasticity of the circuit board]
(Case 1)
As shown in FIG. 3D, the stretchable circuit board 1 in which a plurality of vent holes 13 having an opening shape of 13-1 are arranged is not extended in the X-axis direction or the Y-axis direction (example). As a result, in the case of (1) in FIG. 3D (state before expansion and contraction), air permeability is ensured by the ventilation holes 13. However, when expanded and contracted in the X-axis direction or the Y-axis direction, the openings of all the ventilation holes 13 are closed in the same manner according to the expansion rate of the elastic circuit board 1, and finally, as an example, (1) in FIG. It is considered that all the openings of the ventilation holes 13 may be completely closed at substantially the same time as in the states shown in 2) and (3).

(Case 2)
Next, regarding the stretchable circuit board 1 composed of a combination of the ventilation holes 13 having the shape of the opening 13-1 and the ventilation holes 13 having the shape of the opening 13-2, the situation at the time of expansion and contraction is examined. It is shown in FIG. 3E. When the stretchable circuit board 1 is stretched in the X-axis direction, the shape 13-1 can be seen in the change due to the stretching from the state (1) in FIG. 3E (before stretching) to the state (2) in FIG. 3E. The opening of the shape 13-2 and the opening of the shape 13-2 are changed to openings having different opening states. As shown in (2) of FIG. 3E, even if the opening of shape 13-1 is substantially closed, the opening of shape 13-2 is the opening of the ventilation hole 13 of shape 13-1. Compared to, it maintains a wide open state. That is, the combination of the shapes of the openings of the ventilation holes 13 of the case 2 increases the opening ratio of the ventilation holes 13 on the surface of the elastic insulating layer 11 when the elastic circuit board 1 expands and contracts more than the case 1. It turns out that it can be kept high. For this reason, it is preferable that the plurality of ventilation holes 13 include ventilation holes 13 having different openings.

(Case 3)
Next, regarding the ventilation hole 13 having the shape of the opening 13-2, the stretchable circuit board 1 composed of a combination of a row having the major axis direction as the Y-axis direction and a row having the major axis direction as the X-axis direction. The situation at the time of expansion and contraction is shown in FIG. 3F. When the stretchable circuit board 1 is stretched in the X-axis direction, as can be seen in the change from the state (1) in FIG. 3F (before stretching) to (2) in FIG. 3F, in the state before stretching, the major axis direction. The opening of the ventilation hole 13 in the X-axis direction and the opening of the ventilation hole 13 in the Y-axis direction are changed to openings in different opening states. Further, as shown in (2) of FIG. 3F, even if the openings of the ventilation holes 13 in the row whose major axis direction is the X-axis direction are substantially closed in the state before expansion and contraction, before expansion and contraction In the state, the openings of the ventilation holes 13 in the row whose major axis direction is the Y-axis direction are wider than the openings of the ventilation holes 13 in the row whose major axis direction is the X-axis direction before expansion and contraction. Maintaining the state. Further, a similar state change was observed in the change from the state (1) in FIG. 3F to (3) in FIG. 3F, and as shown in (3) in FIG. 3F, the major axis was in the state before expansion and contraction. Even if the openings of the ventilation holes 13 in the row whose direction is the Y-axis direction are substantially closed, the openings of the ventilation holes 13 in the row whose major axis direction is the X-axis direction before expansion and contraction have a major axis before expansion and contraction. Compared to the openings of the ventilation holes 13 in the row whose direction is the X-axis direction, the open state is maintained. That is, even if the opening of one of the ventilation holes 13 is deformed in the closing direction when the elastic circuit board 1 is extended in the X-axis direction or in the Y-axis direction, the other ventilation hole 13 It is possible to deform the opening in the opening direction. As a result, it can be seen that the opening ratio of the ventilation holes 13 on the surface of the stretchable insulating layer 11 can be maintained higher than in the case 1 in a plurality of stretching directions. For this reason, it is preferable that the plurality of ventilation holes 13 include ventilation holes 13 having different directions of the major axis of the openings, and the ventilation holes 13 having different major axes are arranged in different major directions. It is preferably applied to the stretchable insulating layer 11.

(Case 4)
In the case of the ventilation hole 13 having the shape of the opening 13-3, as shown in Case 3, the elastic circuit board is similar to the combination of the ventilation holes 13 having the shape of the opening 13-2. When 1 expands and contracts, it is easy to maintain a high opening ratio of the ventilation holes 13 on the surface of the elastic insulating layer 11. When the shape of the opening is a polygon represented by a rectangle of shape 13-3, when the stretchable circuit board 1 expands and contracts, breakage is likely to occur from the corner portion, so that the corner of the polygon is It is preferable that the portion of is R-processed. As a result, even when the stretchable circuit board 1 expands and contracts, it is possible to reduce the concentration of stress on a specific portion (particularly, the corner of a polygon) of the ventilation hole 13, and thus it is considered that the strength against breaking can be improved. Be done. The degree of R processing may be appropriately selected according to the size and shape of the opening and the expansion / contraction rate of the stretchable circuit board 1.

In addition, even in the case 1 shown above (in the case of the opening of shape 13-1), if the combination of openings having different sizes is used, the ventilation holes 13 are expanded and contracted as the elastic circuit board 1 expands and contracts. It is considered that the possibility that all the openings of the above are closed at substantially the same time can be avoided (not shown).

[Other Embodiments of Vent 13]
As shown in FIG. 4, the opening of the ventilation hole 13 may have a complicated shape. Specifically, the opening may be polygonal as shown in FIGS. 4 (a) to 4 (c), and may be notched as shown in FIG. 4 (d). Good. Even if the opening is a notch as shown in FIG. 4D, by extending the stretchable circuit board 1, the ventilation hole 13 having the opening is ventilated in the thickness direction of the stretchable insulating layer 11. Become a possible hole.

The ventilation hole 13 may have a shape as shown in FIG. In the case of the shape shown in FIG. 5, since the ventilation holes 13 are provided large, sufficient air permeability can be ensured.

[Aperture ratio of opening]
The aperture ratio of the ventilation holes 13 on the surface of the elastic insulating layer 11 (the total area of the openings of the ventilation holes 13 with respect to the total area of the elastic insulation layer 11 in the surface direction including the total area of the openings of the ventilation holes 13) is As long as breathability can be ensured, there is no particular limitation. The aperture ratio is preferably 0.001 to 45%, more preferably 0.01 to 20%. If the aperture ratio is too low, the air permeability tends to decrease. Further, if the aperture ratio is too high, the strength of the stretchable circuit board tends to decrease even if the air permeability can be ensured. When the aperture ratio is as described above, excellent air permeability can be exhibited while maintaining the strength of the stretchable circuit board, so that more excellent air permeability can be exhibited. The total area of the openings of the ventilation holes 13 is the area obtained by adding all the areas of the plurality of openings formed in the surface direction of the elastic insulating layer 11.

[Size of opening]
The size of the opening of the ventilation hole 13 is not particularly limited as long as the ventilation hole 13 has a size that allows ventilation in the thickness direction of the elastic insulating layer 11. As for the size of the opening, for example, the maximum diameter of the opening (the maximum diameter of the opening in the plane direction of the elastic insulating layer 11) is preferably 100 nm or more and 30 mm or less, and 500 nm or more and 5 mm or less. Is more preferable. Here, the maximum diameter is the diameter when the shape of the opening is circular as in shape 13-1, and the maximum diameter is the diameter when the shape of the opening is elliptical as in shape 13-2. This is the longest diameter (major diameter) of the diameters of the parts. Further, when the shape of the opening is rectangular as in the shape 13-3, it is the length of the long side. When the shape of the opening is other than that, it is the length on the line which is the major axis of the ellipse inscribed in the opening.

If the major axis (maximum diameter) is too short, the air permeability tends to decrease. Further, if the major axis is too long, the strength of the stretchable circuit board tends to decrease even if the air permeability can be ensured. From these facts, if the vent hole of the opening whose major axis is a length within the above range, excellent air permeability can be exhibited while maintaining the strength as an elastic circuit board. Further, since the ventilation through the ventilation holes 13 is easily maintained regardless of the direction in which the stretchable circuit board 1 is extended, more excellent ventilation can be exhibited.

Specific examples of the major axis (maximum diameter) are shown by D1 (D2), D3, D5, D7, and D9 in FIG. 3A, and D11 (D12), D13 (D14), and D15 (D16) in FIG. , D17 (D18). The minor axis (length orthogonal to the major axis: D2, D4, D6, D8, D10 in FIG. 3A) is preferably 100 nm or more and 30 mm or less, and more preferably 500 nm or more and 5 mm or less. preferable.

[Method of forming ventilation holes 13]
The method for forming the ventilation holes 13 is not particularly limited, and examples thereof include a method for forming the ventilation holes 13 in the elastic insulating layer 11 using a drill or a laser.

[Protection of ventilation holes 13]
It is preferable that the stretchable circuit board 1 is further provided with a protective portion that covers the peripheral edge of the opening of the ventilation hole 13 on the surface of the stretchable insulating layer 11. Specifically, the protective portion is for preventing damage to the elastic insulating layer 11 (cracking of the elastic insulating layer 11 generated from the ventilation hole 13 or the like) as shown in FIG. 6A. Protective layer 21 and the like can be mentioned. An enlarged view of the portion A in FIG. 2 is shown in FIG. 6 (a). As shown in FIG. 6A, the peripheral edge of the opening of the ventilation hole 13 is, for example, a portion of the elastic insulating layer 11 in contact with the opening of the ventilation hole 13 (a portion where the protective layer 21c is formed) and a passage. The peripheral surface of the passage of the pore 13 (the portion where the protective layer 21a is formed) and the portion connecting the protective layer 21a and the protective layer 21c (the portion where the protective layer 21b is formed). When the protective portion is the protective layer 21, the protective layer 21 may include any of the protective layer 21a, the protective layer 21b, and the protective layer 21c, or may include them in combination. The protective layer 21 in which any one of the protective layer 21a, the protective layer 21b, and the protective layer 21c is a separate body may be used, or the protective layer 21 in which all of them are integrated may be used, or any two of them may be integrated and the rest. One of the protective layers 21 may be a separate body from the other two. By providing the protective layer 21 as described above, the stretchable circuit board 1 exhibits excellent breathability due to the ventilation holes 13, and damage to the stretchable insulating layer 11 due to the expansion and contraction of the stretchable circuit board 1 occurs. It can be suppressed. The size of the protective layer 21c is such that the formation distance D21 (ratio of elastic circuit board (D21 / R13)) on the elastic insulating layer of the protective layer 21c to the diameter R13 of the ventilation hole 13 shown in FIG. 6A is 0. It is preferably in the range of .05 to 20, more preferably in the range of 0.10 to 10. D21 is preferably in the range of 10 μm to 20 mm, preferably in the range of 20 μm to 10 mm. The thickness (t211 and t212) of the protective layer 21 is preferably in the range of 2 μm to 30 μm, and more preferably in the range of 5 μm to 15 μm.

The material used for the protective layer 21 is not particularly limited, and can be formed by covering with a resin sheet or using various resin compositions, for example. The resin used in the various resin compositions is preferably one that does not hinder the extensibility and tensile elasticity of the stretchable circuit board 1. Further, the protective layer 21 may be an eyelet or the like. That is, the ventilation holes 13 may be protected by eyelets or the like.

The protective portion is not limited to a layered one such as the protective layer 21 as long as it can prevent damage to the elastic insulating layer 11, and is limited to, for example, only the peripheral edge of the opening of the ventilation hole 13. It may be a protective piece provided locally.

[Structure of elastic circuit board suitable for ensuring breathability]
When the elastic circuit board 1 is applied to a wearable device, it is used in contact with an object such as a human body or an article. In such a case, the object becomes a contact with the stretchable circuit board 1. When such an object comes into contact with the elastic circuit board 1, the surface of the elastic circuit board 1 is prevented from being sealed with the opening of the ventilation hole 13 by the contact with the elastic circuit board 1. It is preferable that a sealing prevention means for this purpose is provided. As a specific example of the sealing prevention means, as shown in FIG. 6A, on the surface (adhesion surface) of the elastic insulating layer 11 on the side to be adhered to an object (contact object) such as a human body or an article. Examples thereof include a convex portion 22 and the like. Specifically, it is preferable that the convex portion 22 for separating the object and the stretchable insulating layer 11 is provided on the surface of the stretchable insulating layer 11. As a result, when the stretchable circuit board 1 is used in contact with the object, the convex portion 22 acts as a spacer, and at least the peripheral portion of the convex portion 22 has a surface of the stretchable insulating layer 11 and an object adherent surface. A space is created between them. If there are a plurality of convex portions 22, the space is preferably formed between the adjacent convex portions 22, 22. If the adherend surface of the stretchable circuit board 1 is flat, the opening of the ventilation hole 13 may be sealed by the object, but the presence of the convex portion 22 secures a space (gap) and allows passage. It is possible to prevent the opening of the pore 13 from being blocked. Therefore, suitable air permeability of the stretchable circuit board 1 is ensured. The convex portion 22 is preferably formed in the vicinity of the opening of the ventilation hole 13. The sealing prevention means is not limited to the convex portion 22 as long as it can prevent the opening of the ventilation hole 13 from being sealed by a contact object.

The protective portion (protective layer 21 (21b, 21c)) may have a function as a sealing prevention means (convex portion 22). That is, the air permeability of the stretchable circuit board 1 may be maintained by the convex portion 22, the protective layer 21, and the concave portion 23 formed thereby.

[Size of convex portion 22]
The thickness t22 (Z-axis direction) of the convex portion 22 is preferably in the range of 10 μm to 10 mm, and more preferably in the range of 100 μm to 5 mm. If t22 is too small, it is difficult to obtain the effect of suppressing the opening of the ventilation hole 13 from being blocked by the object, and if t22 is too large, the object and the stretchable circuit board 1 The contact area may be significantly reduced, and the stretchable circuit board 1 may be easily peeled off from the object. The length L22 (X-axis direction and Y-axis direction) of the convex portion 22 in the surface direction (X, Y direction) is not particularly limited, but is preferably in the range of 100 μm to 10 mm, preferably in the range of 500 μm to 5 mm. Is more preferable. If L22 is too small, it is difficult to obtain the effect of suppressing the opening of the ventilation hole 13 from being blocked by the object, and if L22 is too large, the convex portion 22 occupying the elastic insulating layer 11. As the ratio of the above increases and the number and area of the ventilation holes 13 that can be formed in the elastic insulating layer 11 decrease due to restrictions, it is expected that the ventilation will decrease.

[Expandable circuit mounting product 100]
The stretchable circuit mounting product 100 is configured by mounting an electronic component 14 such as a sensor element on a stretchable circuit board 1. The mounting form on the stretchable circuit board 1 is not particularly limited as long as the electronic component 14 connected to the stretchable wiring 12 is mounted. In the stretchable circuit mounted product 100, as shown in FIG. 7, it is preferable that the electronic component 14 is mounted via the land portion 18 and the solder 19. Since FIG. 7 shows the stretchable circuit board 1 on which the electronic component 14 is mounted, both the stretchable circuit board 1 and the stretchable circuit board 100 are shown in FIG. 7. It can be said that.

By providing the land portion 18 in which the stretchable circuit board 1 is connected to the stretchable wiring 12, the electronic component 14 and the like can be connected to the land portion 18 with solder 19 and mounted. That is, as shown in FIG. 7, the stretchable circuit board 1 preferably has a land portion 18 in contact with the stretchable wiring 12 on the surface of the stretchable insulating layer 11. The land portion 18 is not particularly limited, and examples thereof include a patterned metal foil and a land portion 18 printed with a conductive ink containing metal particles.

The stretchable circuit mounting product 100 may further include other members. As shown in FIG. 7, the stretchable circuit mount product 100 preferably further includes, for example, a coating layer 15 that covers the stretchable wiring 12 and the electronic component 14. The covering layer 15 may cover the elastic wiring 12 and the electronic component 14, may also cover other portions, or may cover the entire surface of the elastic insulating layer 11. When the coating layer 15 covers the entire surface of the elastic insulating layer 11, it is preferable that the coating layer 15 is provided with a ventilation hole continuous with the ventilation hole 13 so as not to obstruct the ventilation by the ventilation hole 13. By providing the coating layer 15 in this way, damage to the electronic component 14 and the like can be suppressed. The material used for the coating layer 15 is not particularly limited, and can be formed by covering with a resin sheet or using a resin composition for potting, for example.

It is preferable that the stretchable circuit board 1 is further provided with reinforcing means for reinforcing the stretchable circuit board 1. Examples of the reinforcing means include a reinforcing layer 16 for reinforcing the stretchable circuit board 1 as shown in FIG. 7. The reinforcing means is not limited to a layered shape such as the reinforcing layer 16, as long as it is a member for reinforcing the stretchable circuit board 1, and may be a reinforcing piece or the like in any other form. When the reinforcing means is the reinforcing layer 16, the reinforcing layer 16 may cover the entire surface of the stretchable insulating layer 11 or a part thereof. Since the reinforcing layer 16 is provided for reinforcing the stretchable circuit board 1, it is preferable to provide the reinforcing layer 16 in the region where the electronic component 14 is mounted.

Further, when the reinforcing layer 16 covers the entire surface of the elastic insulating layer 11, it is preferable to provide a ventilation hole continuous with the ventilation hole 13 so as not to obstruct the ventilation by the ventilation hole 13 (not shown). ). The reinforcing layer 16 is provided on the side of the elastic insulating layer 11 provided on the elastic circuit board 1 opposite to the mounting surface on which the electronic component 14 is mounted. By doing so, an elastic circuit board having excellent mechanical strength can be obtained. The material used for the reinforcing layer 16 is not particularly limited, and can be formed by covering with a resin sheet or using a resin composition for potting, for example.

The resin used in the resin composition for potting is preferably one that does not hinder the extensibility and tensile elasticity of the stretchable circuit board 1.

[Protection of ventilation holes 13 when electronic components are mounted]
An enlarged view of the part A in FIG. 7 is shown in FIG. As shown in FIG. 8, the stretchable circuit-mounted product 100 has a protective layer 21 of the vent hole 13 for preventing damage such as cracking of the stretchable insulating layer 11 and the coating layer 15 that occur from the vent hole 13. It is preferable to provide it on the peripheral edge of the opening. Further, also in the case of the elastic circuit board 1 having the reinforcing layer 16 and the elastic circuit mounting product 100, cracks in the elastic insulating layer 11 and the reinforcing layer 16 generated from the ventilation holes 13 penetrating the reinforcing layer 16 are generated. It is preferable that the protective layer 21 for preventing damage is provided on the peripheral edge of the opening of the ventilation hole 13 (not shown).

[Structure of the stretchable circuit mount product that separates the stretchable circuit board from the human body or article]
Similar to the elastic circuit board 1, the elastic circuit mounting product 100 can be used by bringing the elastic circuit mounting product 100 into contact with an object such as a human body or an article. In this case, it is preferable that the convex portion 22 is further provided on the adherend surface of the stretchable insulating layer 11. Specifically, it is preferable that the convex portion 22 for separating the object and the stretchable insulating layer 11 is provided on the surface of the stretchable insulating layer 11. As a result, the opening of the ventilation hole 13 is prevented from being blocked, and suitable ventilation can be ensured.

[Positional relationship between convex portion 22 and electronic components]
An example of the embodiment of the convex portion 22 is shown in FIG. As shown in FIG. 9A, the convex portion 22 is preferably formed on the back surface of the mounting surface of the electronic component 14 of the stretchable insulating layer 11. As shown in FIG. 9B, when the convex portion 22 is formed on the same surface as the mounting surface of the electronic component 14 of the elastic insulating layer 11, the thickness t22 of the convex portion 22 is such that the convex portion 22 is formed. Among the heights of the stretchable insulating layer 11 provided from the same plane to a single or a plurality of electronic components 14, it is preferable that the height is larger than the maximum height t14. As a result, even when the mounting surface of the electronic component 14 of the stretchable insulating layer 11 in the stretchable circuit mounting product 100 is used in contact with the object, the opening of the ventilation hole 13 is closed by the target. It is possible to suppress the electronic component 14 from coming into direct contact with the object. t22 is preferably 1.1 times or more and 5 times or less of t14, and more preferably 1.3 times or more and 3 times or less.

The convex portion 22 may be provided on the surface of the coating layer 15 as shown in FIG. 9C, or may be provided on the surface of the reinforcing layer 16 as shown in FIG. 9D. Further, as shown in FIG. 9E, the convex portion 22 may be provided so as to be buried in the reinforcing layer 16, the covering layer 15 (not shown), and the stretchable insulating layer 11 (not shown).

[Material used for each member of the elastic circuit board according to this embodiment]
(Elastic insulation layer)
The resin composition used for the stretchable insulating layer 11 is not particularly limited in composition as long as the cured product has properties such as the elongation rate and the tensile elastic modulus.

Preferably, the resin composition contains a thermosetting resin and a curing agent thereof. As a more specific example of the resin composition, for example, a resin composition containing a polyrotaxane (A), a thermosetting resin (B) and a curing agent (C) can be mentioned. Each component will be described in more detail below.

Specific examples of the polyrotaxane (A) include polyrotaxane as described in Japanese Patent No. 4482633 or International Publication No. WO2015 / 052853 pamphlet. As the polyrotaxane (A), a commercially available product may be used, and specifically, Celm Superpolymer A1000 manufactured by Advanced Soft Materials Co., Ltd. can be used.

Examples of the thermosetting resin (B) include thermosetting resins such as epoxy resin, phenol resin, polyimide resin, urea resin, melamine resin, unsaturated polyester, and urethane resin without particular limitation. It is preferable to use an epoxy resin.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, aralkyl epoxy resin, phenol novolac type epoxy resin, alkylphenol novolac type epoxy resin, biphenol type epoxy resin, and naphthalene type epoxy. Examples thereof include resins, dicyclopentadiene type epoxy resins, epoxidized products of condensates of phenols and aromatic aldehydes having phenolic hydroxyl groups, triglycidyl isocyanurate, alicyclic epoxy resins and the like. Depending on the situation, one of these may be used alone, or two or more thereof may be used in combination.

As the epoxy resin, for example, an epoxy resin containing two or more epoxy groups in one molecule and having a molecular weight of 500 or more is preferably exemplified. As such an epoxy resin, a commercially available one may be used, for example, JER1003 (manufactured by Mitsubishi Chemical Corporation, molecular weight 1300, bifunctional), EXA-4816 (manufactured by DIC Corporation, molecular weight 824, bifunctional). , YP50 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., molecular weight 60,000 to 80,000, bifunctional) and the like.

Examples of the epoxy resin different from the epoxy resin include alkylene oxide-modified modifying groups having 2 to 3 carbon atoms and having 4 mol or more of the modifying groups contained in 1 mol molecule of the epoxy, and 2 mol or more. Examples thereof include an epoxy resin having an epoxy group and an epoxy equivalent of 450 eq / mol or more. By including the epoxy resin as the thermosetting resin (B) and the curing agent (C), the cured product can obtain a resin composition having the extensibility and the tensile elastic modulus. It is possible. Specific examples of such an epoxy resin include a propylene oxide-added bisphenol A type epoxy resin (made by ADEKA Co., Ltd., EP4003S) and an ethylene oxide-added hydroxyphenylfluorene type epoxy resin (manufactured by Osaka Gas Chemical Co., Ltd., EG). -280) and the like. Further, one type of epoxy resin as described above may be used alone, or two or more types may be used in combination.

A resin composition containing any one component of the polyrotaxane (A) and the thermosetting resin (B) and the curing agent (C) may be used, but both components ((A) and (B) )) And the curing agent (C) are preferably used because the cured product can easily obtain the resin composition having the extensibility and the tensile elastic modulus.

The curing agent (C) is not particularly limited as long as it works as a curing agent for the thermosetting resin (B). In particular, examples of a curing agent that can be preferably used as a curing agent for epoxy resins include curing agents for phenol resins, amine compounds, acid anhydrides, imidazole compounds, sulfide resins, dicyandiamides, and sulfonium salts. The curing agent (C) may be used alone or in combination of two or more. In addition, the resin composition may contain a curing accelerator, if necessary. Examples of the curing accelerator include imidazole compounds and the like.

Further, when the resin composition of the present embodiment is a resin composition containing polyrotaxane, a cross-linking agent may be further added, and such a cross-linking agent is at least a part of the cyclic molecule of the polyrotaxane. It can be used without particular limitation as long as it can form a structure that crosslinks with (at least one reactive group of the cyclic molecule of polyrotaxane), and specific examples thereof include isocyanate and cyanuric chloride.

The ratio of each component in the resin composition is not particularly limited as long as the effects of the present invention can be exhibited, but for example, when all the components (A), (B) and (C) are included, Taking the total of the components (A) to (C) as 100 parts by mass, the polyrotaxane (A) is about 10 to 80 parts by mass, more preferably about 30 to 50 parts by mass; the thermosetting resin (B) is from 10 to 10 parts by mass. 89.9 parts by mass, more preferably 30 to 50 parts by mass; the curing agent (C) is about 0.1 to 30 parts by mass, more preferably about 0.1 to 20 parts by mass. When the resin composition of the present embodiment contains an isocyanate resin as a cross-linking agent, 0 to 50 parts by mass of the isocyanate resin can be added to the polyrotaxane (A) component, and further, 10 to 40 parts by mass can be added. It is preferable to add by mass. When the component (B) and the component (C) are contained and the component (A) is not contained, the total amount of the resin composition is 100 parts by mass, and the thermosetting resin (B) is 50 to 99 parts by mass. It is preferably about 60 to 80 parts by mass; the curing agent (C) is about 1 to 50 parts by mass, more preferably about 1 to 40 parts by mass.

Further, the resin composition may contain other additives such as a curing catalyst (curing accelerator), a flame retardant, a flame retardant aid, a leveling agent, a colorant and the like as necessary, as long as the effects of the present invention are not impaired. May be contained.

The method for preparing the resin composition containing the epoxy resin is not particularly limited, and for example, the epoxy resin, the curing agent and the solvent are mixed so as to be uniform. The solvent used is not particularly limited, and for example, toluene, xylene, methyl ethyl ketone, acetone and the like can be used. These solvents may be used alone or in combination of two or more. Further, here, if necessary, an organic solvent for adjusting the viscosity and various additives may be blended.

By heating and drying the resin composition obtained as described above, the elastic insulating layer of the present embodiment can be obtained by curing while evaporating the solvent.

The method, apparatus, and conditions for heating and drying the resin composition may be various means similar to those used in the past, or improved means thereof. The specific heating temperature and time can be appropriately set depending on the cross-linking agent and solvent used, and for example, the resin composition is cured by heating and drying at 50 to 200 ° C. for about 60 to 180 minutes. be able to.

The stretchable insulating layer 11 (molded body which is a cured product of the resin composition or the like) thus obtained is surface-treated in order to stably form elastic wiring (conductive layer) on one surface thereof. You may do. Further, various additives such as antioxidants, weather stabilizers, flame retardants, antistatic agents and the like can be added as long as their characteristics are not impaired.

(Elastic wiring)
The elastic wiring 12 is not particularly limited as long as it is a wiring having elasticity. The elastic wiring 12 formed by using the conductive composition containing the conductive filler and the elastic binder may be formed, or the elastic wiring 12 having a wavy pattern as shown in FIG. For example, the elastic wiring 12 may be composed of a metal layer such as a copper foil formed in a wavy pattern. Examples of the elastic wiring 12 having a wavy pattern include a zigzag wiring as shown in FIG. 10A, a meander wiring as shown in FIG. 10B, and the like.

Specifically, the conductive composition contains a resin (D) serving as a stretchable binder, a curing agent (E) that reacts with the resin (D), and a conductive filler (F), and the resin. (D) has a functional group having a functional group equivalent of 400 g / eq or more and 10000 g / eq or less, and the cured product of the resin (D) and the conductive composition has a glass transition temperature (Tg). ) Or the softening point is 40 ° C or less, or the elastic conductivity at 30 ° C is less than 1.0 GPa, and the conductive filler (F) has an intrinsic volume resistivity at room temperature of 1 × 10 ^-4 Ω. Examples thereof include a resin composition composed of a conductive substance having a size of cm or less.

Below, each component will be described.

The component of the molecular structure of the resin (D) may be a single component, or a plurality of types may be used in combination at an arbitrary ratio. It is preferable that the molecular structure of the resin (D) is a molecular structure containing at least one selected from (meth) acrylic acid ester, styrene, and nitrile as a component. Specific examples thereof are preferably epoxy-modified (meth) acrylic acid ester, hydroxyl group-modified (meth) acrylic acid ester, carboxyl group-modified (meth) acrylic acid ester, and the like.

The resin (D) preferably has a weight average molecular weight of 50,000 or more. As a result, it is considered that bleeding is less likely to occur when a conductive pattern is printed using the conductive composition. On the other hand, the upper limit of the weight average molecular weight is not particularly limited, but if the molecular weight exceeds 3 million, the viscosity may increase and the handleability may decrease. Therefore, the weight average molecular weight range of the resin (D) is set. It is preferably 50,000 or more and 3 million or less, and more preferably 100,000 or more and 1 million or less.

As the curing agent (E), various curing agents can be used without particular limitation as long as they have reactivity with the resin (D) as described above. Specific examples of the curing agent (E) include imidazole compounds, amine compounds, phenol compounds, acid anhydride compounds, isocyanate compounds, mercapto compounds, onium salts, radical generators such as peroxides, and light. Examples include acid generators.

The conductive filler (F) is made of a conductive substance having an intrinsic volume resistivity of 1 × 10 ^-4 Ω · cm or less at room temperature. When a material having an intrinsic volume resistivity exceeding 1 × 10 ^-4 Ω · cm at room temperature is used, the volume resistivity of the conductive composition is approximately 1 × 10 ^-3 Ω ·, although it depends on the blending amount. It is cm to 1 x 10 ^-2 Ω · cm. Therefore, in the case of a circuit, the resistance value becomes high and the power loss becomes large.

Examples of the conductive substance (conductive substance having an intrinsic volume resistivity of 1 × 10 ^-4 Ω · cm or less at room temperature) include simple substances composed of metal elements such as silver, copper, and gold, and oxidation containing these elements. Examples include compounds such as substances, nitrides, carbides and alloys. In addition to the conductive filler (F), a conductive or semi-conductive conductive auxiliary agent may be added to the conductive composition for the purpose of further improving the conductivity. As such a conductive or semi-conductive auxiliary agent, a conductive polymer, an ionic liquid, carbon black, acetylene black, carbon nanotubes, an inorganic compound used as an antistatic agent, or the like can be used, and only one kind can be used. It may be used or two or more types may be used at the same time.

The conductive filler (F) preferably has a flat shape, and preferably has a thickness and an aspect ratio in the in-plane longitudinal direction of 10 or more. When the aspect ratio is 10 or more, not only the surface area of the conductive filler with respect to the mass ratio becomes large and the efficiency of conductivity increases, but also the adhesion with the resin component is improved and the elasticity is improved. .. When the aspect ratio is 1000 or less, it is preferably 10 or more and 1000 or less, and more preferably 20 or more and 500 or less, from the viewpoint of ensuring better conductivity and printability. Examples of the conductive filler having such an aspect ratio include a conductive filler having a tap density of 6.0 g / cm ³ or less measured by the tap method. Further, when the tap density is 2.0 g / cm ³ or less, the aspect ratio is further increased, which is more preferable.

Regarding the blending ratio of the conductive filler (F) in the conductive composition, the blending ratio of the conductive filler (F) to the total amount of the conductive composition is 40 to 95% by mass in terms of mass ratio. It is preferable in terms of conductivity, cost, and printability, and more preferably 60 to 85% by mass.

The particle size of the conductive filler (F) is not particularly limited, but the average particle size measured by a laser light scattering method from the viewpoint of printability at the time of screen printing and an appropriate viscosity in kneading of the formulation. (Particle size at 50% cumulative volume; D50) is preferably 0.5 μm or more and 30 μm or less, and more preferably 1.5 μm or more and 20 μm or less.

The conductive filler (F) is preferably a conductive filler whose surface is coupled. Alternatively, the conductive composition may contain a coupling agent. This has the advantage that the adhesion between the binder resin and the conductive filler is further improved.

The coupling agent added to the conductive composition or for coupling the conductive filler can be used without particular limitation as long as it is adsorbed on the filler surface or reacts with the filler surface. Specific examples of the coupling agent include a silane coupling agent, a titanate-based coupling agent, and an aluminum-based coupling agent.

When the coupling agent is used in the conductive composition, the amount added thereof is preferably about 1 to 20% by mass with respect to the entire resin composition.

The ratio of each component in the conductive composition is not particularly limited as long as the effects of the present invention can be exhibited, and the blending ratio of the resin (D): the curing agent (E) is the type of resin and curing agent. Therefore, it can be appropriately determined in consideration of the equivalent ratio and the like.

In addition to the above components, additives and the like can be added to the conductive composition depending on the purpose. Examples of additives include elastomers, surfactants, dispersants, colorants, fragrances, plasticizers, pH adjusters, viscosity regulators, ultraviolet absorbers, antioxidants, lubricants and the like.

The method for forming the elastic wiring 12 is not particularly limited, and for example, by applying or printing the conductive composition on the elastic insulating layer 11 as described above, a coating film of the conductive composition can be applied. Examples thereof include a method of forming and forming a desired wiring (conductive pattern).

The conductive pattern or the like formed by the elastic wiring 12 can be formed on the surface of the elastic insulating layer 11 by the following steps. That is, first, a coating film is formed by applying or printing the conductive composition on the stretchable insulating layer 11, and volatile components contained in the coating film are removed by drying. The resin (D) and the curing agent (E) are cured by the subsequent curing steps such as heating, electron beam, and light irradiation, and the coupling agent and the conductive filler (F) are combined with the resin (D). By the step of reacting with the curing agent (E), a conductive pattern by the elastic wiring 12 can be formed. Each condition in the curing step and the reaction step is not particularly limited, and may be appropriately set depending on the type of resin, curing agent, filler, etc. and the desired form.

The step of applying the conductive composition on the substrate (on the elastic insulating layer 11) is not particularly limited, and for example, a coating method such as an applicator, a wire bar, a comma roll, or a gravure roll, a screen, a flat plate offset, or the like. A printing method using flexo, inkjet, stamping, dispense, squeegee, or the like can be used.

When the elastic wiring 12 is composed of a metal layer such as copper foil, the wiring expands and contracts with a change in the shape of the elastic wiring 12, like the wiring formed in the wavy pattern shown in FIG. Therefore, it is preferable that the structure is such that the disconnection of the wiring and the increase of the resistance value can be suppressed.

[Summary]
According to such a configuration, the stretchable circuit board 1 and the stretchable circuit mounted product 100 are operated due to excellent breathability, suppression of damage to the electronic components, moisture passing through the vent holes 13, and the like. It is possible to suppress the occurrence of defects and the like. Further, for example, when a light emitting sheet provided with an LED element or the like on the elastic circuit board according to the present embodiment is used for a display device such as a huge digital signage used in a stadium or the like, the ventilation hole 13 is used. It also has the advantage of being able to prevent it from breaking or being blown by the wind. The vents also contribute to cooling electronic components such as LED elements.

This application is based on Japanese Patent Application No. 2019-12080 filed on June 27, 2019, the contents of which are included in the present application.

In order to express the present invention, the present invention has been appropriately and sufficiently described through the embodiments above, but those skilled in the art can easily modify and / or improve the above embodiments. Should be recognized. Therefore, unless the modified or improved form implemented by a person skilled in the art is at a level that deviates from the scope of rights of the claims stated in the claims, the modified form or the improved form is the scope of rights of the claims. It is interpreted as being included in.

According to the present invention, an elastic circuit board having excellent breathability and an elastic circuit mounted product are provided.

Claims (13)

1. With elastic insulation layer,
   It is provided with elastic wiring provided on at least one of the surface and the inside of the elastic insulating layer.
   The stretchable insulating layer has an opening at a position electrically insulated from the stretchable wiring, and is formed with a vent hole that allows ventilation in the thickness direction of the stretchable insulating layer. An elastic circuit board characterized by.
2. The stretchable circuit board according to claim 1, wherein a plurality of the vent holes are formed in the stretchable insulating layer.
3. The stretchable circuit board according to claim 1 or 2, wherein the opening of the vent has at least one shape selected from a circular shape, an elliptical shape, and a polygonal shape.
4. The stretchable circuit board according to any one of claims 1 to 3, wherein the opening ratio of the ventilation holes on the surface of the stretchable insulating layer is 0.001 to 45%.
5. The stretchable circuit board according to any one of claims 1 to 4, wherein the maximum diameter of the opening is 100 nm or more and 30 mm or less.
6. The stretchable circuit board according to any one of claims 1 to 5, further comprising a protective portion that covers the peripheral edge of the opening of the vent on the surface of the stretchable insulating layer.
7. Claims 1 to 1 to claim 1, wherein the surface of the stretchable circuit board is provided with a sealing prevention means for preventing the opening of the ventilation hole from being sealed by an object of contact with the surface of the stretchable circuit board. 6. The elastic circuit board according to any one of 6.
8. The stretchable circuit board according to any one of claims 1 to 7, further comprising a land portion electrically connected to the stretchable wiring on the surface of the stretchable insulating layer.
9. The stretchable circuit board according to any one of claims 1 to 8, further comprising a reinforcing means for reinforcing the stretchable circuit board.
10. The stretchable circuit board according to any one of claims 1 to 9, wherein the stretchable wiring is formed by using a conductive composition.
11. The stretchable circuit board according to any one of claims 1 to 10, wherein the stretchable wiring has a wavy pattern.
12. A stretchable circuit-mounted product in which electronic components are mounted on the stretchable circuit board according to any one of claims 1 to 11.
13. The stretchable circuit-mounted product according to claim 12, further comprising a coating layer that covers the stretchable wiring and the electronic component.

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