CN219780513U

CN219780513U - Stretchable mounting substrate

Info

Publication number: CN219780513U
Application number: CN202190000668.XU
Authority: CN
Inventors: 浅井辽; 胜勇人; 西田圭佑
Original assignee: Murata Manufacturing Co Ltd
Current assignee: Murata Manufacturing Co Ltd
Priority date: 2020-12-15
Filing date: 2021-11-04
Publication date: 2023-09-29
Anticipated expiration: 2031-11-04
Also published as: WO2022130816A1

Abstract

The stretchable mounting board includes a stretchable base material, stretchable wires provided on one main surface side of the stretchable base material, and electronic components electrically connected to the stretchable wires, the stretchable wires include a first stretchable wire and a second stretchable wire that is connected to one end side of the first stretchable wire at a connection portion in an overlapping manner, the electronic components include terminals protruding in a first direction and electrically connected to the other end side of the first stretchable wire, the terminals, the first stretchable wire, and the second stretchable wire form a wire path toward the first direction, a plurality of wire paths are arranged in a second direction orthogonal to the first direction, and a shortest distance between the stretchable wires in the second direction in a region between the connection portions, that is, a distance between the terminals, is larger than a shortest distance between the terminals in the second direction.

Description

Stretchable mounting substrate

Technical Field

The present utility model relates to a stretchable mounting board.

Background

In recent years, biological information is acquired and analyzed by using a wiring board, whereby the state of a living body (for example, a human body) and the like are managed.

When the wiring board is used in a state of being attached to a living body, stretchability capable of following the movement of the living body is required for the wiring board. Therefore, wiring used for such a wiring board is required to be less likely to be broken even if the wiring board is stretched. Since such a wiring generally has a relatively high resistivity, it is required to increase the thickness of the wiring from the viewpoint of lowering the resistance.

In general, when forming wiring, the electroconductive paste for wiring is printed by screen printing, but if the electroconductive paste for wiring is printed thicker to form wiring having a larger thickness, the electroconductive paste tends to flow in the width direction, causing print bleeding. In the wiring board, two wirings are sometimes provided so that a part thereof overlaps with each other, but when such two wirings are formed, the thickness increases at the overlapping part of the two wirings, so that print bleeding is more likely to occur.

As a structure for suppressing print-bleed, patent document 1 discloses a thick film integrated circuit in which a lower conductor is formed on an insulating substrate, an insulating layer is formed on the lower conductor, and an upper conductor intersecting the lower conductor is further formed on the insulating layer, wherein at least one insulating layer is extended along the lower conductor in a junction between the lower conductor and the upper conductor. According to the thick film integrated circuit described in patent document 1, since the insulating layer extends along the lower conductor at the junction between the lower conductor and the upper conductor, the paste is prevented from flowing in the lateral direction by the extending portion when the pattern of the intersecting conductor is printed.

Patent document 1: japanese laid-open patent publication No. 1-93771

There are cases where electronic components are mounted on a wiring board by connection to wiring. As such electronic components, with recent miniaturization, electronic components having a small inter-terminal distance, that is, so-called narrow pitch electronic components, are often used.

In order to mount electronic components with a narrow pitch, it is necessary to form a plurality of wirings with a narrow pitch, but in this case, in order to suppress print bleeding at the time of forming the wirings, it is conceivable to form a plurality of insulating layers in advance by using the structure described in patent document 1. However, since print bleed occurs at the time of formation of the insulating layers, adjacent insulating layers are spread and contacted with each other. Therefore, after forming the insulating layer, it is difficult to form a wiring between adjacent insulating layers.

Further, even if two wirings are formed to partially overlap each other between adjacent insulating layers, it is difficult to turn on the two wirings if the insulating layers are expanded to a portion where the two wirings are to be connected. When two wirings are formed to partially overlap each other between adjacent insulating layers, the insulating layer needs to be formed to have a thickness equal to or greater than the total thickness of the two wirings in order to suppress print bleeding at the portion where the two wirings overlap.

As described above, in the structure described in patent document 1, there is room for improvement in the case of mounting electronic components with a narrow pitch. In addition, in the structure described in patent document 1, a step of providing an insulating layer is required, so that the manufacturing cost increases.

On the other hand, when two wiring lines are partially overlapped with each other, for example, first, a conductive paste for one wiring line is printed by a screen printing method, and then a conductive paste for the other wiring line is printed so that a portion thereof overlaps with a conductive paste for one wiring line. In general, since a screen printing plate different from that used in printing of the electroconductive paste for one wiring is used in printing of the electroconductive paste for the other wiring, there is a case where the electroconductive paste for the other wiring is printed so as to be offset in the width direction from the electroconductive paste for the one wiring at a connection portion with the electroconductive paste for the one wiring due to an influence of misalignment, deformation, or the like of the screen printing plate. As described above, print bleeding is likely to occur due to the large thickness of the connection portion between the conductive paste for one wiring and the conductive paste for the other wiring. Thus, when a plurality of paths including two wirings are formed at a narrow pitch for mounting electronic components at a narrow pitch, if the above-described print misalignment and print bleed-out occur, there is a concern that one wiring belonging to one path contacts the other wiring belonging to the other path in the adjacent two paths, and the wirings are short-circuited.

Disclosure of Invention

The present utility model has been made to solve the above-described problems, and an object of the present utility model is to provide a stretchable mounting substrate capable of suppressing a short circuit between a first stretchable wiring and a second stretchable wiring even when a distance between terminals of an electronic component is small.

The flexible mounting substrate of the present utility model is characterized by comprising: a stretchable substrate; a stretchable wiring provided on one principal surface side of the stretchable base material; and an electronic component electrically connected to the stretchable wiring, the stretchable wiring including a first stretchable wiring and a second stretchable wiring, the second stretchable wiring being connected to one end side of the first stretchable wiring at a connection portion, the electronic component having a terminal protruding in a first direction and electrically connected to the other end side of the first stretchable wiring, the terminal, the first stretchable wiring, and the second stretchable wiring forming a wiring path in the first direction, a plurality of wiring paths being arranged in a second direction orthogonal to the first direction, a distance between the wirings being larger than a distance between the terminals in the two wiring paths adjacent to each other in the second direction, the distance between the wirings being a shortest distance in the second direction between the stretchable wirings in a region between the connection portions, the distance between the terminals being a shortest distance between the terminals in the second direction between the terminals.

According to the present utility model, it is possible to provide a stretchable mounting substrate capable of suppressing a short circuit between a first stretchable wiring and a second stretchable wiring even when the inter-terminal distance of an electronic component is small.

Drawings

Fig. 1 is a schematic plan view partially showing a stretchable mounting substrate according to embodiment 1 of the present utility model.

Fig. 2 is a schematic cross-sectional view showing a portion corresponding to the line A1-A2 in fig. 1.

Fig. 3 is a schematic plan view partially showing a stretchable mounting board according to a modification of embodiment 1 of the present utility model.

Fig. 4 is a schematic cross-sectional view showing a portion corresponding to the line B1-B2 in fig. 3.

Fig. 5 is a schematic plan view partially showing a stretchable mounting substrate according to embodiment 2 of the present utility model.

Fig. 6 is a schematic plan view partially showing a stretchable mounting substrate according to embodiment 3 of the present utility model.

Fig. 7 is a schematic plan view partially showing a stretchable mounting substrate according to embodiment 4 of the present utility model.

Detailed Description

The stretchable mounting board according to the present utility model will be described below. The present utility model is not limited to the following configuration, and may be appropriately modified within a range not departing from the gist of the present utility model. The present utility model also provides a structure in which a plurality of preferred structures described below are combined.

The embodiments described below are examples, and it is needless to say that substitution or combination of the portions of the structures described in the different embodiments can be performed. In embodiments other than embodiment 1, description of the same matters as those in embodiment 1 will be omitted, and differences will be mainly described. In particular, the same operational effects caused by the same structure are not mentioned in order in each embodiment.

Embodiment 1

Fig. 1 is a schematic plan view partially showing a stretchable mounting substrate according to embodiment 1 of the present utility model. Fig. 2 is a schematic cross-sectional view showing a portion corresponding to the line A1-A2 in fig. 1.

As shown in fig. 1 and 2, the stretchable mounting board 1 includes a stretchable base 10, first stretchable wirings 21a, first stretchable wirings 21b, first stretchable wirings 21c, first stretchable wirings 21d, second stretchable wirings 31a, second stretchable wirings 31b, second stretchable wirings 31c, second stretchable wirings 31d, and electronic components 40.

In the present specification, as shown in fig. 1, 2, and the like, the first direction, the second direction, and the third direction are defined by D1, D2, and D3, respectively. The first direction D1, the second direction D2, and the third direction D3 are orthogonal to each other. In fig. 1, 2, and the like, the first direction D1 and the second direction D2 are directions along the one main surface 10a of the stretchable base material 10, and the third direction D3 is a direction orthogonal to the one main surface 10a of the stretchable base material 10.

In the present specification, unless otherwise specified, various lengths such as a width, a thickness, and a distance are expressed as lengths in a state where the stretchable mounting substrate is not stretched. The width is defined by the length in the second direction D2. The thickness is defined by the length in the third direction D3. The length of the flexible mounting board is measured by looking down or cutting through the flexible mounting board by an optical microscope.

The stretchable substrate 10 preferably contains at least one resin selected from the group consisting of polyurethane-based resins, silicone-based resins, acrylic-based resins, and olefin-based resins. Examples of the polyurethane resin include Thermoplastic Polyurethane (TPU).

When the stretchable mounting substrate 1 is attached to a living body, the thickness of the stretchable base material 10 is preferably 100 μm or less, more preferably 50 μm or less, from the viewpoint of not inhibiting stretching of the surface of the living body. The thickness of the stretchable base material 10 is preferably 10 μm or more.

The first stretchable wiring 21a is provided on the one principal surface 10a side of the stretchable base material 10, more specifically, on the one principal surface 10a of the stretchable base material 10.

Similarly, the first stretchable wiring 21b, the first stretchable wiring 21c, and the first stretchable wiring 21d are provided on the one principal surface 10a side of the stretchable base material 10, more specifically, on the one principal surface 10a of the stretchable base material 10.

As shown in fig. 1, the width W1 of the first stretchable wiring 21a is the same as the width W2 of the second stretchable wiring 31 a.

Similarly, as shown in fig. 1, the widths of the first stretchable wiring 21b, the first stretchable wiring 21c, and the first stretchable wiring 21d are the same as the widths of the second stretchable wiring 31b, the second stretchable wiring 31c, and the second stretchable wiring 31d, respectively.

The widths of the first stretchable wirings 21a, 21b, 21c, and 21d are preferably the same as each other as shown in fig. 1, but may be different from each other or partially different from each other.

As shown in fig. 2, the thickness T1 of the first stretchable wiring 21a is the same as the thickness T2 of the second stretchable wiring 31 a.

Similarly, although not shown, the thicknesses of the first stretchable wiring 21b, the first stretchable wiring 21c, and the first stretchable wiring 21d are the same as the thicknesses of the second stretchable wiring 31b, the second stretchable wiring 31c, and the second stretchable wiring 31d, respectively.

The thicknesses of the first stretchable wiring 21a, the first stretchable wiring 21b, the first stretchable wiring 21c, and the first stretchable wiring 21d are preferably the same, but may be different from each other or partially different from each other.

The second stretchable wiring line 31a is provided on the one principal surface 10a side of the stretchable base material 10, more specifically, is provided on the one principal surface 10a of the stretchable base material 10 except for a part thereof.

Similarly, the second stretchable wiring 31b, the second stretchable wiring 31c, and the second stretchable wiring 31d are provided on the one principal surface 10a side of the stretchable base material 10, and more specifically, are provided on the one principal surface 10a of the stretchable base material 10 except for a part thereof.

As shown in fig. 1 and 2, the second stretchable wiring line 31a is connected to the first stretchable wiring line 21a at the connecting portion 51a so as to overlap with the one end portion 21aa side. More specifically, in the connection portion 51a, the second stretchable wiring 31a overlaps the first stretchable wiring 21a on the opposite side of the first stretchable wiring 21a from the one main surface 10a of the stretchable base material 10. As shown in fig. 1, the second stretchable wiring line 31a is superimposed on the first stretchable wiring line 21a in a planar view of the stretchable mounting substrate 1 by an optical microscope.

Similarly, the second stretchable wiring 31b is connected to the first stretchable wiring 21b so as to overlap the one end portion 21ba side of the first stretchable wiring 51b at the connection portion 51b, and more specifically, the second stretchable wiring 31b overlaps the first stretchable wiring 21b on the opposite side of the first stretchable wiring 21b from the one main surface 10a of the stretchable base material 10 at the connection portion 51 b. The second stretchable wiring 31c is connected to the first stretchable wiring 21c so as to overlap the one end portion 21ca side of the connecting portion 51c, and more specifically, the second stretchable wiring 31c overlaps the first stretchable wiring 21c on the opposite side of the first stretchable wiring 21c from the one main surface 10a of the stretchable base material 10 in the connecting portion 51 c. The second stretchable wiring 31d is connected to the first stretchable wiring 21d so as to overlap the one end portion 21da side of the first stretchable wiring 51d at the connection portion 51d, and more specifically, the second stretchable wiring 31d overlaps the first stretchable wiring 21d on the opposite side of the first stretchable wiring 21d from the one main surface 10a of the stretchable base material 10.

Unlike the configuration shown in fig. 1 and 2, the second stretchable wiring line 31a may overlap the first stretchable wiring line 21a on the one main surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring line 21a in the connection portion 51 a. Similarly, in the connection portion 51b, the second stretchable wiring 31b may overlap the first stretchable wiring 21b on the one principal surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 21 b. In the connection portion 51c, the second stretchable wiring 31c may overlap the first stretchable wiring 21c on the one principal surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 21 c. In the connection portion 51d, the second stretchable wiring 31d may overlap the first stretchable wiring 21d on the one principal surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 21 d. In other words, the positional relationship between the first stretchable wiring line and the second stretchable wiring line in the connection portion may be reversed with respect to the configuration shown in fig. 1 and 2.

The widths of the second stretchable wirings 31a, 31b, 31c, and 31d are preferably the same as shown in fig. 1, but may be different from each other or partially different from each other.

The thicknesses of the second stretchable wiring 31a, the second stretchable wiring 31b, the second stretchable wiring 31c, and the second stretchable wiring 31d are preferably the same, but may be different from each other or partially different from each other.

The first stretchable wiring 21a, the first stretchable wiring 21b, the first stretchable wiring 21c, the first stretchable wiring 21d, the second stretchable wiring 31a, the second stretchable wiring 31b, the second stretchable wiring 31c, and the second stretchable wiring 31d include, for example, a metal filler and a resin.

Examples of the metal filler included in each stretchable wiring include silver filler, copper filler, and nickel filler.

The metal types of the metal fillers included in the respective stretchable wirings are preferably the same as each other, but may be different from each other or partially different.

Examples of the shape of the metal filler included in each stretchable wire include a plate shape and a spherical shape.

The shapes of the metal fillers included in the respective stretchable wirings are preferably the same as each other, but may be different from each other or partially different.

The resin included in each stretchable wiring is preferably at least one elastomer resin selected from the group consisting of an acrylic resin, an epoxy resin, a urethane resin, and a silicone resin.

The types of resins included in the respective stretchable wirings are preferably the same as each other, but may be different from each other or partially different.

The thickness T3 of the connection portion 51a is preferably 20 μm or more. On the other hand, if the thickness T3 of the connection portion 51a is too large, the in-plane rigidity of the connection portion 51a is too high. Accordingly, since stress is easily concentrated on the connection portion 51a during expansion and contraction of the stretchable mounting substrate 1, the first stretchable wiring 21a and the second stretchable wiring 31a are not easily uniformly contracted, or resistance of the first stretchable wiring 21a and the second stretchable wiring 31a is easily increased. From such a viewpoint, the thickness T3 of the connection portion 51a is preferably 50 μm or less.

Similarly, the thicknesses of the connection portions 51b, 51c, and 51d are preferably 20 μm or more, respectively. The thicknesses of the connection portions 51b, 51c, and 51d are preferably 50 μm or less, respectively.

The thicknesses of the connection portions 51a, 51b, 51c, and 51d are preferably the same as each other, but may be different from each other or partially different from each other.

The connection portions 51a, 51b, 51c, and 51d are preferably present within 5cm from the center of the electronic component 40.

The electronic component 40 has terminals 41a, 41b, 41c, and 41D protruding in the first direction D1, respectively.

The terminal 41a is electrically connected to the other end 21ab side of the first stretchable wiring 21a via solder or the like. More specifically, the terminal 41a is provided on the first stretchable wiring 21a on the opposite side of the one main surface 10a of the stretchable base material 10.

Similarly, the terminal 41b is electrically connected to the other end portion 21bb side of the first stretchable wiring 21b, and more specifically, is provided on the first stretchable wiring 21b on the opposite side of the one main surface 10a of the stretchable base material 10. The terminal 41c is electrically connected to the other end portion 21cb side of the first stretchable wiring 21c, and more specifically, is provided on the first stretchable wiring 21c on the opposite side of the one main surface 10a of the stretchable base material 10. The terminal 41d is electrically connected to the other end 21db side of the first stretchable wiring 21d, and more specifically, is provided on the first stretchable wiring 21d on the opposite side of the one main surface 10a of the stretchable base material 10.

Examples of the electronic component 40 include an amplifier (an operational amplifier, a transistor, or the like), a diode, an Integrated Circuit (IC), a capacitor, a resistor, and an inductor.

The terminal 41a, the first stretchable wiring 21a, and the second stretchable wiring 31a form a wiring path 61a toward the first direction D1.

Similarly, the terminal 41b, the first stretchable wiring 21b, and the second stretchable wiring 31b constitute a wiring path 61b toward the first direction D1. The terminal 41c, the first stretchable wiring 21c, and the second stretchable wiring 31c constitute a wiring path 61c toward the first direction D1. The terminal 41D, the first stretchable wiring 21D, and the second stretchable wiring 31D form a wiring path 61D toward the first direction D1.

In the present specification, the terminal, the first stretchable wiring, and the second stretchable wiring forming the wiring path toward the first direction means that the terminal, the first stretchable wiring, and the second stretchable wiring are substantially oriented toward the first direction when the entire wiring path is observed. In addition, at least one selected from the group consisting of the terminal, the first stretchable wiring, and the second stretchable wiring may partially extend in a direction other than the first direction on the wiring path.

The wiring paths 61a, 61b, 61c, and 61D are arranged in the second direction D2. In other words, the connection portions 51a, 51b, 51c, and 51D are arranged in the second direction D2.

In the wiring paths 61a and 61b adjacent to each other in the second direction D2, the inter-wiring distance K1, which is the shortest distance between the stretchable wires in the second direction D2 in the region between the connection portions 51a and 51b, is larger than the inter-terminal distance P1, which is the shortest distance between the terminals 41a and 41b in the second direction D2.

Similarly, in the wiring paths 61b and 61c adjacent to each other in the second direction D2, the inter-wiring distance K2, which is the shortest distance between the stretchable wires in the region between the connection portion 51b and the connection portion 51c in the second direction D2, is larger than the inter-terminal distance P2, which is the shortest distance between the terminals 41b and 41c in the second direction D2. In the wiring paths 61c and 61D adjacent to each other in the second direction D2, the inter-wiring distance K3, which is the shortest distance between the stretchable wires in the second direction D2 in the region between the connection portion 51c and the connection portion 51D, is larger than the inter-terminal distance P3, which is the shortest distance between the terminals 41c and 41D in the second direction D2.

As shown in fig. 1, in the connection portion 51a, the first stretchable wiring 21a does not extend in the second direction D2 as compared with the second stretchable wiring 31a, and in the state in which the first stretchable wiring 21b does not extend in the second direction D2 as compared with the second stretchable wiring 31b in the connection portion 51b, the inter-wiring distance K1 is defined by the shortest distance in the second direction D2 between the second stretchable wiring 31a and the second stretchable wiring 31b in the region between the connection portion 51a and the connection portion 51 b. In addition, as shown in fig. 1, when the widths of the second stretchable wiring lines 31a and 31b can be regarded as being substantially constant along the first direction D1, the distance in the second direction D2 between the end of the second stretchable wiring line 31a on the electronic component 40 side and the end of the second stretchable wiring line 31b on the electronic component 40 side may be representatively defined as the wiring line distance K1.

The inter-wiring distance K2 and the inter-wiring distance K3 can be defined in the same manner as the inter-wiring distance K1.

In manufacturing the stretchable mounting substrate, for example, first, the electroconductive paste for the first stretchable wiring is printed at a plurality of positions by a screen printing method. Thereafter, the conductive paste for the second stretchable wiring is printed by a screen printing method at a plurality of positions so as to overlap one end side of the conductive paste for the first stretchable wiring printed at a plurality of positions. In printing of the second conductive paste for telescopic wiring, a screen printing plate different from that used in printing of the first conductive paste for telescopic wiring is generally used, and therefore, there is an influence of misalignment, deformation, and the like of the screen printing plate, and the second conductive paste for telescopic wiring is printed so as to be offset in the second direction with respect to the first conductive paste for telescopic wiring at each connection portion with the first conductive paste for telescopic wiring. In addition, since the thickness of each connecting portion is large, print bleeding is likely to occur. In this way, when a plurality of paths including the first stretchable wiring and the second stretchable wiring are formed at a narrow pitch in order to mount electronic components having a small inter-terminal distance, if the print misalignment and the print bleed-out described above occur, there is a concern that the first stretchable wiring belonging to one path and the second stretchable wiring belonging to the other path will come into contact with each other in the two adjacent paths and short-circuit occurs.

In contrast, in the stretchable mounting substrate 1, as described above, the inter-wiring distance in the region between the connection portions is larger than the inter-terminal distance in the two wiring paths adjacent to each other in the second direction D2. In other words, in the stretchable mounting substrate 1, even if the inter-terminal distance of the electronic component 40 is small, the inter-wiring distance in the region between the connection portions can be sufficiently ensured. Therefore, in the case where an electronic component having a small inter-terminal distance is mounted as the electronic component 40, even if the above-described print misalignment and print bleed-out occur, it is possible to suppress the first flexible wiring belonging to one wiring path from being in contact with the second flexible wiring belonging to the other wiring path and shorting between the two adjacent wiring paths in the second direction D2. More specifically, since the inter-wiring distance K1 is larger than the inter-terminal distance P1 in the wiring paths 61a and 61b adjacent to each other in the second direction D2, a short circuit between the first stretchable wiring 21a belonging to the wiring path 61a and the second stretchable wiring 31b belonging to the wiring path 61b or a short circuit between the second stretchable wiring 31a belonging to the wiring path 61a and the first stretchable wiring 21b belonging to the wiring path 61b can be suppressed. Similarly, among the wiring paths 61b and 61c adjacent to each other in the second direction D2, the short-circuiting between the first flexible wiring and the second flexible wiring can be suppressed even in the wiring paths 61c and 61D adjacent to each other in the second direction D2.

As described above, according to the stretchable mounting substrate 1, even if the inter-terminal distance of the electronic component 40 is small, the short-circuit between the first stretchable wiring line and the second stretchable wiring line can be suppressed.

The inter-wiring distance K1 is preferably 300 μm or more. Accordingly, even if the inter-terminal distance P1 is small in the wiring paths 61a and 61b adjacent to each other in the second direction D2, the short-circuiting between the first stretchable wiring 21a and the second stretchable wiring 31b or the short-circuiting between the second stretchable wiring 31a and the first stretchable wiring 21b is easily suppressed. On the other hand, if the inter-wiring distance K1 is too large, the stretchable base material 10 having a large width is required correspondingly, so that the size of the stretchable mounting substrate 1 is not easily reduced. From such a viewpoint, the inter-wiring distance K1 is preferably 1000 μm or less.

Similarly, the inter-wiring distance K2 and the inter-wiring distance K3 are preferably 300 μm or more, respectively. Further, the inter-wiring distance K2 and the inter-wiring distance K3 are preferably 1000 μm or less, respectively.

The inter-wiring distance K1, the inter-wiring distance K2, and the inter-wiring distance K3 may be the same as each other, may be different from each other, or may be partially different from each other.

The inter-terminal distance P1 may be 300 μm or less. Even if the inter-terminal distance P1 is small, short-circuiting between the first stretchable wiring 21a and the second stretchable wiring 31b or short-circuiting between the second stretchable wiring 31a and the first stretchable wiring 21b can be suppressed in the wiring paths 61a and 61b adjacent to each other in the second direction D2. On the other hand, in practical use of the electronic component 40, the inter-terminal distance P1 may be 50 μm or more.

Similarly, the inter-terminal distance P2 and the inter-terminal distance P3 may be 300 μm or less, respectively. The inter-terminal distance P2 and the inter-terminal distance P3 may be 50 μm or more, respectively.

The inter-terminal distance P1, the inter-terminal distance P2, and the inter-terminal distance P3 are often the same as each other in practical use of the electronic component 40, but may be different from each other or partially different from each other.

In the stretchable mounting board 1, as described above, the inter-wiring distance in the region between the connection portions is larger than the inter-terminal distance in the two adjacent wiring paths in the second direction D2, but such a configuration can be realized by the wiring paths having the following configurations.

In the wiring path 61a, the first stretchable wiring 21a extends in the first direction D1 as a whole and extends in the second direction D2 partially by bending.

Similarly, in the wiring path 61b, the first stretchable wiring 21b extends in the first direction D1 as a whole and extends in the second direction D2 partially by bending. In the wiring path 61c, the first stretchable wiring 21c extends in the first direction D1 as a whole and extends in the second direction D2 partially by bending. In the wiring path 61D, the first stretchable wiring 21D extends in the first direction D1 as a whole and extends in the second direction D2 partially by bending.

Thus, the wiring paths 61a, 61b, 61c, and 61D are classified into the first type of wiring path 71 in which the first flexible wiring extends partially in the second direction D2.

In the stretchable mounting substrate 1, as shown in fig. 1, the wiring paths 61a, 61b, 61c, and 61D as the first wiring path 71 are provided to be line-symmetrical with respect to a straight line S passing through the center of the electronic component 40 and extending in the first direction D1. In this way, in the stretchable mounting substrate 1, the inter-wiring distance in the region between the connection portions is larger than the inter-terminal distance in the two adjacent wiring paths in the second direction D2.

In the stretchable mounting substrate 1, the second stretchable wiring lines 31a, 31b, 31c, and 31D extend in the first direction D1 within the range shown in fig. 1, but at least one second stretchable wiring line selected from the group consisting of the second stretchable wiring lines 31a, 31b, 31c, and 31D may extend in the second direction D2 in a region outside the range shown in fig. 1, or may extend in a direction other than the first direction D1 and the second direction D2.

The stretchable mounting board 1 may further include an electrode connected to at least one second stretchable wiring selected from the group consisting of the second stretchable wiring 31a, the second stretchable wiring 31b, the second stretchable wiring 31c, and the second stretchable wiring 31 d. The stretchable mounting board 1 can function as a sensor by being attached to a living body via such an electrode.

The electrode is preferably a gel electrode. By passing through the gel electrode, the flexible mounting board 1 is easily attached to a living body. The gel electrode is made of, for example, a conductive gel material containing water, ethanol, a humectant, an electrolyte, and the like. Examples of such a gel material include hydrogels.

The stretchable mounting board 1 is manufactured by the following method, for example.

< step of forming stretchable wiring >)

First, a first electroconductive paste containing a first metal filler and a first resin is printed at a plurality of positions on one main surface 10a of the stretchable base material 10 by a screen printing method. At this time, by adjusting the pattern of the screen printing plate, the first electroconductive paste is printed to extend in the first direction D1 as a whole at a plurality of positions, and to extend partially in the second direction D2 by bending.

Next, a second electroconductive paste containing a second metal filler and a second resin is printed on one main surface 10a of the stretchable base material 10 by a screen printing method, and is printed so as to overlap one end side of the first electroconductive paste printed at a plurality of positions.

Thereafter, by performing heat treatment on the first conductive paste and the second conductive paste, the first stretchable wiring 21a, the first stretchable wiring 21b, the first stretchable wiring 21c, and the first stretchable wiring 21d are formed from the first conductive paste, and the second stretchable wiring 31a, the second stretchable wiring 31b, the second stretchable wiring 31c, and the second stretchable wiring 31d are formed from the second conductive paste.

The second stretchable wiring formed in this way is connected to the first stretchable wiring so as to overlap with the first stretchable wiring at the connecting portion at one end portion side thereof, more specifically, the second stretchable wiring overlaps with the first stretchable wiring at the opposite side of the first stretchable wiring from the one main surface 10a of the stretchable base material 10. In the connection portion, the second stretchable wiring may overlap the first stretchable wiring on the one main surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring.

In the above-described method, after the printing of the first electroconductive paste and the printing of the second electroconductive paste are sequentially performed, the first electroconductive paste and the second electroconductive paste are heat-treated, so that the first stretchable wiring group including the first stretchable wiring 21a, the first stretchable wiring 21b, the first stretchable wiring 21c, and the first stretchable wiring 21d, and the second stretchable wiring group including the second stretchable wiring 31a, the second stretchable wiring 31b, the second stretchable wiring 31c, and the second stretchable wiring 31d are formed at the same timing.

In contrast, unlike the above-described method, the first stretchable wiring 21a, the first stretchable wiring 21b, the first stretchable wiring 21c, and the first stretchable wiring 21d may be formed by sequentially performing printing of the first electroconductive paste and heat treatment of the first electroconductive paste, and then the second stretchable wiring 31a, the second stretchable wiring 31b, the second stretchable wiring 31c, and the second stretchable wiring 31d may be formed by sequentially performing printing of the second electroconductive paste and heat treatment of the second electroconductive paste. In other words, the first stretchable wiring group including the first stretchable wiring 21a, the first stretchable wiring 21b, the first stretchable wiring 21c, and the first stretchable wiring 21d, and the second stretchable wiring group including the second stretchable wiring 31a, the second stretchable wiring 31b, the second stretchable wiring 31c, and the second stretchable wiring 31d may be formed at different timings.

Examples of the first metal filler and the second metal filler include silver filler, copper filler, and nickel filler.

The metal species of the first metal filler and the second metal filler are preferably the same as each other, but may be different from each other.

Examples of the shape of the first metal filler and the second metal filler include a plate shape and a spherical shape.

The first metal filler and the second metal filler are preferably identical in shape to each other, but may be different in shape from each other.

The first resin and the second resin are preferably at least one elastomer resin selected from the group consisting of acrylic resins, epoxy resins, urethane resins, and silicone resins.

The first resin and the second resin are preferably the same in resin type, but may be different in resin type.

The first conductive paste and the second conductive paste may each further contain a solvent. Examples of such solvents include diethylene glycol monoethyl ether acetate.

When the first electroconductive paste and the second electroconductive paste contain a solvent, the solvent contained in the first electroconductive paste and the solvent contained in the second electroconductive paste are preferably the same in kind, but may be different in kind.

< procedure of mounting electronic component >

The first stretchable wiring 21a, the first stretchable wiring 21b, the first stretchable wiring 21c, and the first stretchable wiring 21d are provided on the other end side thereof, and the first stretchable wiring 21a, the first stretchable wiring 21b, the first stretchable wiring 21c, and the first stretchable wiring 21d are provided on the side opposite to the one main surface 10a of the stretchable base material 10, and then the terminals 41a, 41b, 41c, and 41d of the electronic component 40 are mounted via solder paste or the like, and then heat treatment is performed by a reflow oven. Thus, the terminals 41a, 41b, 41c, and 41d of the electronic component 40 are electrically connected to the other end sides of the first stretchable wiring 21a, 21b, 21c, and 21d via solder, respectively.

Thus, the electronic component 40 is mounted. The terminal, the first stretchable wiring, and the second stretchable wiring form a wiring path oriented in the first direction D1, and the four wiring paths are arranged in the second direction D2. More specifically, the wiring paths 61a, 61b, 61c, and 61D are arranged in the second direction D2.

As described above, the stretchable mounting board 1 is manufactured.

In the stretchable mounting substrate 1 thus manufactured, the inter-wiring distance in the region between the connection portions is larger than the inter-terminal distance in the two wiring paths adjacent to each other in the second direction D2.

Modification of embodiment 1

In the stretchable mounting substrate according to the modification of embodiment 1 of the present utility model, unlike the stretchable mounting substrate according to embodiment 1 of the present utility model, the width of the second stretchable wiring is larger than the width of the first stretchable wiring, and the thickness of the second stretchable wiring is larger than the thickness of the first stretchable wiring.

Fig. 3 is a schematic plan view partially showing a stretchable mounting board according to a modification of embodiment 1 of the present utility model. Fig. 4 is a schematic cross-sectional view showing a portion corresponding to the line B1-B2 in fig. 3.

As shown in fig. 3, in the stretchable mounting substrate 1a, the width W2 of the second stretchable wiring line 31a is larger than the width W1 of the first stretchable wiring line 21 a. Accordingly, since the second stretchable wiring 31a is easily lowered in resistance, even when the inter-terminal distance P1 is small and it is difficult to increase the width W1 of the first stretchable wiring 21a, a current is easily caused to flow to the electronic component 40 through the second stretchable wiring 31 a.

Similarly, as shown in fig. 3, the widths of the second stretchable wiring 31b, the second stretchable wiring 31c, and the second stretchable wiring 31d are larger than the widths of the first stretchable wiring 21b, the first stretchable wiring 21c, and the first stretchable wiring 21d, respectively.

As shown in fig. 4, in the stretchable mounting substrate 1a, the thickness T2 of the second stretchable wiring line 31a is larger than the thickness T1 of the first stretchable wiring line 21 a. Accordingly, the second stretchable wiring 31a is easily reduced in resistance, and therefore, a current is easily caused to flow to the electronic component 40 through the second stretchable wiring 31 a.

Similarly, although not shown, the thicknesses of the second stretchable wiring 31b, the second stretchable wiring 31c, and the second stretchable wiring 31d are larger than the thicknesses of the first stretchable wiring 21b, the first stretchable wiring 21c, and the first stretchable wiring 21d, respectively.

In the stretchable mounting board 1a, as shown in fig. 3, the hard coat layer 90 may be provided so as to cover at least a range from the electronic component 40 to the connection portion 51a, the connection portion 51b, the connection portion 51c, and the connection portion 51 d. By providing the hard coat layer 90 in this manner, the electronic component 40 is protected from the outside. In addition, when the stretchable mounting board 1a stretches, durability of the connection portion 51a, the connection portion 51b, the connection portion 51c, and the connection portion 51d, in which stress is easily concentrated, improves. In particular, in the stretchable mounting substrate 1a, when the connection portion 51a, the connection portion 51b, the connection portion 51c, and the connection portion 51d are covered with the hard coat layer 90, at least a part of each of the second stretchable wirings 31a, 31b, 31c, and 31d having a large width is covered with the hard coat layer 90, so that the stretchable mounting substrate 1a is strengthened with respect to stretching.

Examples of the constituent material of the hard coat layer 90 include an elastomer resin such as polyvinyl chloride, polyethylene, polystyrene, polycarbonate, polyvinylidene fluoride, polyimide, liquid crystal polymer, polytetrafluoroethylene, phenol resin, epoxy resin, polyurethane resin, acrylic resin, silicone resin, and styrene-butadiene resin.

As described above, the flexible mounting board according to the modification of embodiment 1 of the present utility model has been described in a manner that the width of the second flexible wiring is larger than the width of the first flexible wiring and the thickness of the second flexible wiring is larger than the thickness of the first flexible wiring, but even in a manner that the width of the second flexible wiring is larger than the width of the first flexible wiring or the thickness of the second flexible wiring is larger than the thickness of the first flexible wiring, the second flexible wiring is similarly liable to have low resistance, so that the current is liable to flow to the electronic component through the second flexible wiring.

Embodiment 2

In the stretchable mounting substrate according to embodiment 2 of the present utility model, unlike the stretchable mounting substrate according to embodiment 1 of the present utility model, the plurality of wiring paths include a second type of wiring path in which the first stretchable wiring line extends linearly in the first direction, and the second type of wiring path is provided at the outermost side in the second direction among the plurality of wiring paths. Except for this point, the stretchable mounting substrate according to embodiment 2 of the present utility model is the same as the stretchable mounting substrate according to embodiment 1 of the present utility model.

As shown in fig. 5, the stretchable mounting board 2 includes a stretchable base 10, a first stretchable wiring 22a, a first stretchable wiring 22b, a first stretchable wiring 22c, a first stretchable wiring 22d, a second stretchable wiring 31a, a second stretchable wiring 31b, a second stretchable wiring 31c, a second stretchable wiring 31d, and an electronic component 40.

One end 22aa side of the first stretchable wire 22a is connected to the second stretchable wire 31a so as to overlap the connection portion 52a, and the other end 22ab side is electrically connected to the terminal 41a via solder or the like. In the connection portion 52a, the second stretchable wiring 31a overlaps the first stretchable wiring 22a on the opposite side of the first stretchable wiring 22a from the one main surface 10a of the stretchable base material 10.

Similarly, the first stretchable wiring 22b is connected to the second stretchable wiring 31b at the connecting portion 52b so that one end 22ba side thereof is overlapped with the other end 22bb side thereof, and is electrically connected to the terminal 41 b. In the connection portion 52b, the second stretchable wiring 31b overlaps the first stretchable wiring 22b on the opposite side of the first stretchable wiring 22b from the one main surface 10a of the stretchable base material 10. One end 22ca side of the first stretchable wire 22c is connected to the second stretchable wire 31c in a manner overlapping the connection portion 52c, and the other end 22cb side is electrically connected to the terminal 41 c. In the connection portion 52c, the second stretchable wiring 31c overlaps the first stretchable wiring 22c on the opposite side of the first stretchable wiring 22c from the one main surface 10a of the stretchable base material 10. One end 22da side of the first stretchable wiring 22d is connected to the second stretchable wiring 31d so as to overlap the connection portion 52d, and the other end 22db side is electrically connected to the terminal 41 d. In the connection portion 52d, the second stretchable wiring 31d overlaps the first stretchable wiring 22d on the opposite side of the first stretchable wiring 22d from the one main surface 10a of the stretchable base material 10.

Unlike the configuration shown in fig. 5, in the connection portion 52a, the second stretchable wiring 31a may overlap the first stretchable wiring 22a on the one main surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 22 a. Similarly, in the connection portion 52b, the second stretchable wiring 31b may overlap the first stretchable wiring 22b on the one main surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 22 b. In the connection portion 52c, the second stretchable wiring 31c may overlap the first stretchable wiring 22c on the one main surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 22 c. In the connection portion 52d, the second stretchable wiring 31d may overlap the first stretchable wiring 22d on the one main surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 22 d. In other words, the positional relationship between the first stretchable wiring line and the second stretchable wiring line in the connection portion may be reversed with respect to the configuration shown in fig. 5.

The terminal 41a, the first stretchable wiring 22a, and the second stretchable wiring 31a form a wiring path 62a toward the first direction D1.

Similarly, the terminal 41b, the first stretchable wiring 22b, and the second stretchable wiring 31b constitute a wiring path 62b toward the first direction D1. The terminal 41c, the first stretchable wiring 22c, and the second stretchable wiring 31c constitute a wiring path 62c toward the first direction D1. The terminal 41D, the first stretchable wiring 22D, and the second stretchable wiring 31D form a wiring path 62D toward the first direction D1.

The wiring paths 62a, 62b, 62c, and 62D are arranged in the second direction D2. In other words, the connection portions 52a, 52b, 52c, and 52D are arranged in the second direction D2.

In the wiring paths 62a and 62b adjacent to each other in the second direction D2, the inter-wiring distance L1, which is the shortest distance between the stretchable wires in the second direction D2 in the region between the connection portions 52a and 52b, is larger than the inter-terminal distance P1.

Similarly, in the wiring paths 62b and 62c adjacent to each other in the second direction D2, the inter-wiring distance L2, which is the shortest distance between the stretchable wires in the second direction D2 in the region between the connection portion 52b and the connection portion 52c, is larger than the inter-terminal distance P2. In the wiring paths 62c and 62D adjacent to each other in the second direction D2, the inter-wiring distance L3, which is the shortest distance between the stretchable wires in the second direction D2 in the region between the connection portion 52c and the connection portion 52D, is larger than the inter-terminal distance P3.

As described above, in the stretchable mounting substrate 2, the distance between wirings in the region between the connection portions is larger than the distance between the terminals in the two wiring paths adjacent to each other in the second direction D2, and therefore the same operational effects as those of the stretchable mounting substrate 1 can be obtained.

As described above, the stretchable mounting board 2 is realized by the wiring paths having the following configuration in which the inter-wiring distance in the region between the connection portions is larger than the inter-terminal distance in the two adjacent wiring paths in the second direction D2.

In the wiring path 62b, the first stretchable wiring 22b extends in the first direction D1 as a whole and extends in the second direction D2 partially by bending. In the wiring path 62c, the first stretchable wiring 22c extends in the first direction D1 as a whole and extends in the second direction D2 partially by bending. In the wiring path 62D, the first stretchable wiring 22D extends in the first direction D1 as a whole and extends in the second direction D2 partially by bending. Thus, the wiring paths 62b, 62c, and 62d are classified into the first type of wiring path 71 described above.

In the wiring path 62a, the first stretchable wiring 22a linearly extends in the first direction D1. Thus, the wiring path 62a is classified into a second type of wiring path 72 in which the first flexible wiring extends linearly in the first direction D1, unlike the first type of wiring path 71.

In the stretchable mounting substrate 2, the wiring path 62b, the wiring path 62c, and the wiring path 62D, which are the first type wiring path 71, are provided in this order on the same side (lower side in fig. 5) in the second direction D2 as the wiring path 62a, which is the second type wiring path 72. In this way, in the stretchable mounting substrate 2, the inter-wiring distance in the region between the connection portions is larger than the inter-terminal distance in the two adjacent wiring paths in the second direction D2.

In the stretchable mounting substrate 2, the wiring path 62a as the second type wiring path 72 is provided on the outermost side (uppermost side in fig. 5) in the second direction D2 among the wiring paths 62a, 62b, 62c, and 62D. Accordingly, a wide space can be provided between the wiring path 62a and the end (upper end in fig. 5) of the stretchable base material 10 in the layout of the wiring path, and therefore, other electronic components and the like can be mounted in the wide space for use.

In the stretchable mounting substrate 2, the first stretchable wiring 22a extends linearly in the first direction D1 in the wiring path 62a, and therefore the path length is shorter than the wiring paths 62b, 62c, and 62D. Therefore, in the stretchable mounting substrate 2, by selecting the wiring path 62a as the wiring path through which the large current flows, the voltage drop due to the large current can be suppressed.

Embodiment 3

Unlike the stretchable mounting substrate according to embodiment 2 of the present utility model, the stretchable mounting substrate according to embodiment 3 of the present utility model is not provided with the second wiring path at the outermost side in the second direction among the plurality of wiring paths. Except for this point, the stretchable mounting substrate according to embodiment 3 of the present utility model is the same as the stretchable mounting substrate according to embodiment 2 of the present utility model.

As shown in fig. 6, the stretchable mounting board 3 includes a stretchable base 10, a first stretchable wiring 23a, a first stretchable wiring 23b, a first stretchable wiring 23c, a first stretchable wiring 23d, a second stretchable wiring 31a, a second stretchable wiring 31b, a second stretchable wiring 31c, a second stretchable wiring 31d, and an electronic component 40.

One end 23aa side of the first stretchable wire 23a is connected to the second stretchable wire 31a so as to overlap the connection portion 53a, and the other end 23ab side is electrically connected to the terminal 41a via solder or the like. In the connection portion 53a, the second stretchable wiring line 31a overlaps the first stretchable wiring line 23a on the opposite side of the one main surface 10a of the stretchable base material 10.

Similarly, the first stretchable wiring 23b is connected to the second stretchable wiring 31b at one end 23ba side thereof in a superimposed manner at the connection portion 53b, and is electrically connected to the terminal 41b at the other end 23bb side thereof. In the connection portion 53b, the second stretchable wiring 31b overlaps the first stretchable wiring 23b on the opposite side of the first stretchable wiring 23b from the one main surface 10a of the stretchable base material 10. One end 23ca side of the first stretchable wire 23c is connected to the second stretchable wire 31c in a manner overlapping the connection portion 53c, and the other end 23cb side is electrically connected to the terminal 41 c. In the connection portion 53c, the second stretchable wiring 31c overlaps the first stretchable wiring 23c on the opposite side of the first stretchable wiring 23c from the one main surface 10a of the stretchable base material 10. One end 23da side of the first stretchable wire 23d is connected to the second stretchable wire 31d so as to overlap the connection portion 53d, and the other end 23db side is electrically connected to the terminal 41 d. In the connection portion 53d, the second stretchable wiring 31d overlaps the first stretchable wiring 23d on the opposite side of the first stretchable wiring 23d from the one main surface 10a of the stretchable base material 10.

Unlike the configuration shown in fig. 6, in the connection portion 53a, the second stretchable wiring 31a may overlap the first stretchable wiring 23a on the one main surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 23 a. Similarly, in the connection portion 53b, the second stretchable wiring 31b may overlap the first stretchable wiring 23b on the one principal surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 23 b. In the connection portion 53c, the second stretchable wiring 31c may overlap the first stretchable wiring 23c on the one principal surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 23 c. In the connection portion 53d, the second stretchable wiring 31d may overlap the first stretchable wiring 23d on the one principal surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 23 d. In other words, the positional relationship between the first stretchable wiring line and the second stretchable wiring line in the connection portion may be reversed with respect to the configuration shown in fig. 6.

The terminal 41a, the first stretchable wiring 23a, and the second stretchable wiring 31a form a wiring path 63a toward the first direction D1.

Similarly, the terminal 41b, the first stretchable wiring 23b, and the second stretchable wiring 31b constitute a wiring path 63b toward the first direction D1. The terminal 41c, the first stretchable wiring 23c, and the second stretchable wiring 31c constitute a wiring path 63c toward the first direction D1. The terminal 41D, the first stretchable wiring 23D, and the second stretchable wiring 31D form a wiring path 63D toward the first direction D1.

The wiring paths 63a, 63b, 63c, and 63D are arranged in the second direction D2. In other words, the connection portions 53a, 53b, 53c, and 53D are arranged in the second direction D2.

In the wiring paths 63a and 63b adjacent to each other in the second direction D2, the inter-wiring distance M1, which is the shortest distance between the stretchable wires in the second direction D2 in the region between the connection portions 53a and 53b, is larger than the inter-terminal distance P1.

Similarly, in the wiring paths 63b and 63c adjacent to each other in the second direction D2, the inter-wiring distance M2, which is the shortest distance between the stretchable wires in the second direction D2 in the region between the connection portion 53b and the connection portion 53c, is larger than the inter-terminal distance P2. In the wiring paths 63c and 63D adjacent to each other in the second direction D2, the inter-wiring distance M3, which is the shortest distance between the stretchable wires in the second direction D2 in the region between the connection portions 53c and 53D, is larger than the inter-terminal distance P3.

As described above, in the stretchable mounting substrate 3, the distance between wirings in the region between the connection portions is larger than the distance between the terminals in the two wiring paths adjacent to each other in the second direction D2, and therefore the same operational effects as those of the stretchable mounting substrate 1 can be obtained.

As described above, the stretchable mounting board 3 is realized by the wiring paths having the following configuration in which the inter-wiring distance in the region between the connection portions is larger than the inter-terminal distance in the two adjacent wiring paths in the second direction D2.

In the wiring path 63a, the first stretchable wiring 23a extends in the first direction D1 as a whole and extends in the second direction D2 partially by bending. In the wiring path 63c, the first stretchable wiring 23c extends in the first direction D1 as a whole and extends in the second direction D2 partially by bending. In the wiring path 63D, the first stretchable wiring 23D extends in the first direction D1 as a whole and extends in the second direction D2 partially by bending. Thus, the wiring paths 63a, 63c, and 63d are classified into the first type of wiring path 71 described above.

In the wiring path 63b, the first stretchable wiring 23b extends linearly in the first direction D1. Thus, the wiring path 63b is classified into the second wiring path 72 described above.

In the stretchable mounting substrate 3, a wiring path 63a as a first type wiring path 71 is provided on one side (upper side in fig. 6) in the second direction D2 with respect to a wiring path 63b as a second type wiring path 72, and a wiring path 63c and a wiring path 63D as the first type wiring path 71 are provided on the other side (lower side in fig. 6). In this way, in the stretchable mounting substrate 3, the inter-wiring distance in the region between the connection portions is larger than the inter-terminal distance in the two adjacent wiring paths in the second direction D2.

In the stretchable mounting substrate 3, the first stretchable wiring 23b extends linearly in the first direction D1 in the wiring path 63b, and therefore the path length is shorter than the wiring paths 63a, 63c, and 63D. Therefore, in the stretchable mounting substrate 3, by selecting the wiring path 63b as a wiring path through which a large current flows, a voltage drop due to the large current can be suppressed.

Embodiment 4

In the stretchable mounting substrate according to embodiment 4 of the present utility model, unlike the stretchable mounting substrate according to embodiment 1 of the present utility model, the plurality of wiring paths includes a third wiring path in which the first stretchable wiring portion extends partially in a direction other than the first direction and the second direction. Except for this point, the stretchable mounting substrate according to embodiment 4 of the present utility model is the same as the stretchable mounting substrate according to embodiment 1 of the present utility model.

As shown in fig. 7, the stretchable mounting board 4 includes a stretchable base 10, a first stretchable wiring 24a, a first stretchable wiring 24b, a first stretchable wiring 24c, a first stretchable wiring 24d, a second stretchable wiring 31a, a second stretchable wiring 31b, a second stretchable wiring 31c, a second stretchable wiring 31d, and an electronic component 40.

One end 24aa side of the first stretchable wire 24a is connected to the second stretchable wire 31a so as to overlap the connection portion 54a, and the other end 24ab side is electrically connected to the terminal 41a via solder or the like. In the connection portion 54a, the second stretchable wiring 31a overlaps the first stretchable wiring 24a on the opposite side of the first stretchable wiring 24a from the one main surface 10a of the stretchable base material 10.

Similarly, the first stretchable wiring 24b is connected to the second stretchable wiring 31b at the connecting portion 54b so that one end 24ba side is overlapped with the other end 24bb side, and is electrically connected to the terminal 41 b. In the connection portion 54b, the second stretchable wiring 31b overlaps the first stretchable wiring 24b on the opposite side of the first stretchable wiring 24b from the one main surface 10a of the stretchable base material 10. One end 24ca side of the first stretchable wire 24c is connected to the second stretchable wire 31c in a superimposed manner at the connection portion 54c, and the other end 24cb side is electrically connected to the terminal 41 c. In the connection portion 54c, the second stretchable wiring 31c overlaps the first stretchable wiring 24c on the opposite side of the first stretchable wiring 24c from the one main surface 10a of the stretchable base material 10. One end 24da side of the first stretchable wire 24d is connected to the second stretchable wire 31d so as to overlap the connection portion 54d, and the other end 24db side is electrically connected to the terminal 41 d. In the connection portion 54d, the second stretchable wiring 31d overlaps the first stretchable wiring 24d on the opposite side of the first stretchable wiring 24d from the one main surface 10a of the stretchable base material 10.

Unlike the configuration shown in fig. 7, in the connection portion 54a, the second stretchable wiring 31a may overlap the first stretchable wiring 24a on the one main surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 24 a. Similarly, in the connection portion 54b, the second stretchable wiring 31b may overlap the first stretchable wiring 24b on the one main surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 24 b. In the connection portion 54c, the second stretchable wiring 31c may overlap the first stretchable wiring 24c on the one main surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 24 c. In the connection portion 54d, the second stretchable wiring 31d may overlap the first stretchable wiring 24d on the one main surface 10a side of the stretchable base material 10 with respect to the first stretchable wiring 24 d. In other words, the positional relationship between the first stretchable wiring line and the second stretchable wiring line in the connection portion may be reversed with respect to the configuration shown in fig. 7.

The terminal 41a, the first stretchable wiring 24a, and the second stretchable wiring 31a constitute a wiring path 64a toward the first direction D1.

Similarly, the terminal 41b, the first stretchable wiring 24b, and the second stretchable wiring 31b constitute a wiring path 64b toward the first direction D1. The terminal 41c, the first stretchable wiring 24c, and the second stretchable wiring 31c constitute a wiring path 64c toward the first direction D1. The terminal 41D, the first stretchable wiring 24D, and the second stretchable wiring 31D form a wiring path 64D toward the first direction D1.

The wiring paths 64a, 64b, 64c, and 64D are arranged in the second direction D2. In other words, the connection portions 54a, 54b, 54c, and 54D are arranged in the second direction D2.

In the wiring paths 64a and 64b adjacent to each other in the second direction D2, the inter-wiring distance N1, which is the shortest distance between the stretchable wires in the second direction D2 in the region between the connection portions 54a and 54b, is larger than the inter-terminal distance P1.

Similarly, in the wiring paths 64b and 64c adjacent to each other in the second direction D2, the inter-wiring distance N2, which is the shortest distance between the stretchable wires in the second direction D2 in the region between the connection portion 54b and the connection portion 54c, is larger than the inter-terminal distance P2. In the wiring paths 64c and 64D adjacent to each other in the second direction D2, the inter-wiring distance N3, which is the shortest distance between the stretchable wires in the second direction D2 in the region between the connection portion 54c and the connection portion 54D, is larger than the inter-terminal distance P3.

As described above, in the stretchable mounting substrate 4, the distance between wirings in the region between the connection portions is larger than the distance between the terminals in the two wiring paths adjacent to each other in the second direction D2, and therefore the same operational effects as those of the stretchable mounting substrate 1 can be obtained.

As described above, the stretchable mounting board 4 is realized by the wiring paths having the following configuration in which the inter-wiring distance in the region between the connection portions is larger than the inter-terminal distance in the two adjacent wiring paths in the second direction D2.

In the wiring path 64a, the first stretchable wiring 24a extends in the first direction D1 as a whole and extends partially in a direction other than the first direction D1 and the second direction D2 (in fig. 7, in a direction inclined with respect to the first direction D1 and the second direction D2).

Similarly, in the wiring path 64b, the first stretchable wiring 24b extends in the first direction D1 as a whole and extends partially in a direction other than the first direction D1 and the second direction D2. In the wiring path 64c, the first stretchable wiring 24c extends in the first direction D1 as a whole and extends partially in a direction other than the first direction D1 and the second direction D2. In the wiring path 64D, the first stretchable wiring 24D extends in the first direction D1 as a whole and extends partially in a direction other than the first direction D1 and the second direction D2.

Thus, the wiring paths 64a, 64b, 64c, and 64D are classified into the third wiring path 73 in which the first flexible wiring extends partially in the direction other than the first direction D1 and the second direction D2, respectively.

In the stretchable mounting substrate 4, as shown in fig. 7, the wiring paths 64a, 64b, 64c, and 64D as the third wiring path 73 are provided to be line-symmetrical with respect to a straight line S passing through the center of the electronic component 40 and extending in the first direction D1. In this way, in the stretchable mounting substrate 4, the inter-wiring distance in the region between the connection portions is larger than the inter-terminal distance in the two adjacent wiring paths in the second direction D2.

In the above-described stretchable mounting substrates 1, 2, and 3, the first type wiring paths 71 are provided adjacently in the second direction D2 in at least a partial region, so that the first stretchable wirings are likely to be locally close to each other in the portion bent in the second direction D2. For example, in the stretchable mounting substrate 1, as shown in fig. 1, the first stretchable wiring 21a and the first stretchable wiring 21b are locally adjacent to each other, and the first stretchable wiring 21c and the first stretchable wiring 21d are locally adjacent to each other. If the first flexible wirings are locally too close to each other, there is a high risk of short-circuiting the first flexible wirings.

In contrast, in the stretchable mounting substrate 4, as shown in fig. 7, the first type wiring path 71 is not provided, but the third type wiring path 73 is provided adjacently in the second direction D2, so that the first stretchable wirings are not easily locally adjacent to each other. Therefore, the first flexible wiring is less likely to be short-circuited.

In each embodiment, the second stretchable wiring is connected to the first stretchable wiring so as to overlap one end portion side of the connecting portion, and more specifically, the second stretchable wiring overlaps the first stretchable wiring on the opposite side of the first stretchable wiring from the one main surface of the stretchable base material. In contrast, the second stretchable wiring may be connected to the first stretchable wiring so as to overlap one end portion side of the first stretchable wiring at the connection portion, but unlike the above-described embodiments, the second stretchable wiring overlaps the first stretchable wiring on one main surface side of the stretchable base material at the connection portion. In other words, the positional relationship between the first stretchable wiring and the second stretchable wiring in the connection portion may be reversed with respect to each embodiment.

In each embodiment, the number of wiring paths is four, that is, the number of terminals, first flexible wirings, and second flexible wirings is four, respectively. In contrast, the number of wiring paths may be two, three, or five or more, unlike the respective embodiments. That is, the number of the terminals, the first stretchable wirings, and the second stretchable wirings may be two, three, or five or more.

Description of the reference numerals

1. 1a, 2, 3, 4 …,10 …,10a …, one main surface of the 10a …,21a, 21b, 21c, 21D, 22a, 22b, 22c, 22D, 23a, 23b, 23c, 23D, 24a, 24b, 24c, 24D …,21aa, 21ba, 21ca, 21da, 22aa, 22ba, 22ca, 22da, 23aa, 23ba, 23ca, 23da, 24aa, 24ba, 24ca, 24da …, one end of the first flexible wiring, 21ab, 21bb, 21cb, 21db, 22ab, 22bb, 22cb, 22db, 23ab, 23bb, 23cb, 23db, 24ab, 24bb, 24db …,31a, 31b, 31c, 31D, 31b, 41D, 41c, 41D, 51a, 51b, 51c, 51D, 52a, 52b, 52c, 52D, 53a, 53b, 53c, 53D, 54a, 54b, 54c, 54D … connection, 61a, 61b, 61c, 61D, 62a, 62b, 62c, 62D, 63a, 63b, 63c, 63D, 64a, 64b, 64c, 64D … wiring paths, 71 … first wiring paths, 72 … second wiring paths, 73 … third wiring paths, 90 … hard coat, D1 … first direction, D2 … second direction, D3 … third direction, K1, K2, K3, L1, L2, L3, M1, M2, M3, N1, N2, N3 … wiring inter-terminal distances P1, P2, P3 … inter-terminal distances S … straight lines, T1 first thickness … first thickness-flexible wiring width … second thickness-flexible wiring width ….

Claims

1. A stretchable mounting board is characterized by comprising:

a stretchable substrate;

a stretchable wiring provided on one principal surface side of the stretchable base material; and

an electronic component electrically connected to the flexible wiring,

the flexible wiring includes a first flexible wiring and a second flexible wiring which is connected to the first flexible wiring at a connecting portion so as to overlap one end side of the first flexible wiring,

the electronic component has a terminal protruding in a first direction and electrically connected to the other end side of the first flexible wiring,

the terminal, the first stretchable wiring, and the second stretchable wiring form a wiring path in the first direction,

a plurality of wiring paths are arranged in a second direction orthogonal to the first direction,

in the two adjacent wiring paths in the second direction, a distance between the wirings is larger than a distance between the terminals, the distance between the wirings is a shortest distance in the second direction between the stretchable wirings in the region between the connecting portions, and the distance between the terminals is a shortest distance in the second direction between the terminals.

2. The flexible mounting substrate according to claim 1, wherein,

in the connection portion, the second stretchable wiring line overlaps the first stretchable wiring line on the opposite side of the one main surface of the stretchable base material with respect to the first stretchable wiring line.

3. The flexible mounting substrate according to claim 1 or 2, wherein,

the distance between the wirings is 300 μm or more.

4. The flexible mounting substrate according to claim 1 or 2, wherein,

the distance between the terminals is 300 μm or less.

5. The flexible mounting substrate according to claim 1 or 2, wherein,

the second stretchable wiring has a width larger than that of the first stretchable wiring.

6. The flexible mounting substrate according to claim 1 or 2, wherein,

the second stretchable wiring has a thickness larger than that of the first stretchable wiring.

7. The flexible mounting substrate according to claim 1 or 2, wherein,

the plurality of wiring paths include a first wiring path in which the first flexible wiring partially extends in the second direction.

8. The flexible mounting substrate according to claim 1 or 2, wherein,

The plurality of wiring paths include a second wiring path in which the first stretchable wiring line extends linearly in the first direction.

9. The flexible mounting substrate according to claim 8, wherein,

the second wiring path is provided on the outermost side in the second direction among the plurality of wiring paths.

10. The flexible mounting substrate according to claim 1 or 2, wherein,

the plurality of wiring paths include a third wiring path in which the first stretchable wiring portion extends in a direction other than the first direction and the second direction.

11. The flexible mounting substrate according to claim 1 or 2, wherein,

the hard coat layer is provided so as to cover at least a range from the electronic component to the connection portion.