Stretchable device

Abstract

Provided in an embodiment of the present invention is a stretchable device comprising: a stretchable base material; first stretchable wiring that is disposed on the stretchable base material and that has a first electrode part; second stretchable wiring that is disposed on the first stretchable wiring and that has a second electrode part; and an interlayer sheet that is disposed between the first stretchable wiring and the second stretchable wiring, wherein the interlayer sheet has a sheet part and at least one first via part that is provided to the sheet part, and the first via part has, at a portion thereof, a connection region that connects the first electrode part and the second electrode part.

Description

Technical Field

[0001] The present invention relates to a stretchable device.

Background Art

[0002] Conventionally, a stretchable device including a stretchable substrate, a first stretchable wiring disposed on the stretchable substrate, and a second stretchable wiring disposed on the first stretchable wiring and connected via a via has been known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional stretchable device, the inventor of the present application has found that there are matters to be improved in the following points. Specifically, if the positional accuracy between the via used to interconnect two stretchable wirings and the electrode portion of the upper second stretchable wiring is not constant, it may be difficult to improve the connection reliability between the electrode portion of the lower first stretchable wiring and the electrode portion of the upper second stretchable wiring. Particularly when the entire device stretches and contracts like a stretchable device, displacement is likely to occur, so high connection reliability is required.

[0005] Therefore, an object of the present invention is to provide a stretchable device capable of improving the connection reliability between the electrode portions of two adjacent stretchable wirings.

Means for Solving the Problems

[0006] In order to achieve the above object, in one embodiment of the present invention, The invention comprises a stretchable substrate, a first stretchable wiring disposed on the stretchable substrate and having a first electrode portion, a second stretchable wiring disposed on the first stretchable wiring and having a second electrode portion, and an interlayer sheet disposed between the first stretchable wiring and the second stretchable wiring. The interlayer sheet includes a sheet portion and at least one first via portion provided in the sheet portion. A stretchable device is provided in which the first via portion partially has a connecting region that connects the first electrode portion and the second electrode portion. [Effects of the Invention]

[0007] According to one embodiment of the present invention, a stretchable device makes it possible to improve the connection reliability between the electrode portions of two adjacent stretchable wirings. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic plan view showing a stretchable device according to the first embodiment of the present invention. [Figure 2A] Figure 2A is a schematic plan view showing a stretchable device according to a second embodiment of the present invention. [Figure 2B] Figure 2B is a schematic plan view showing a modified example of the stretchable device according to the second embodiment of the present invention. [Figure 3A] Figure 3A is a schematic plan view showing step 1 of the method for manufacturing a stretchable device according to the second embodiment of the present invention. [Figure 3B] Figure 3B is a schematic plan view showing step 2 of the method for manufacturing a stretchable device according to the second embodiment of the present invention. [Figure 3C] Figure 3C is a schematic plan view showing step 3 of the method for manufacturing a stretchable device according to the second embodiment of the present invention. [Figure 3D] Figure 3D is a schematic plan view showing step 4 of the method for manufacturing a stretchable device according to the second embodiment of the present invention. [Figure 3E]Figure 3E is a schematic plan view showing step 5 of the method for manufacturing a stretchable device according to the second embodiment of the present invention. [Figure 4A] Figure 4A is a schematic plan view showing step 1 of the method for manufacturing a modified example of the stretchable device according to the second embodiment of the present invention. [Figure 4B] Figure 4B is a schematic plan view showing step 2 of the method for manufacturing a modified example of the stretchable device according to the second embodiment of the present invention. [Figure 4C] Figure 4C is a schematic plan view showing step 3 of the method for manufacturing a modified example of the stretchable device according to the second embodiment of the present invention. [Figure 4D] Figure 4D is a schematic plan view showing step 4 of the method for manufacturing a modified example of the stretchable device according to the second embodiment of the present invention. [Figure 4E] Figure 4E is a schematic plan view showing step 5 of the method for manufacturing a modified example of the stretchable device according to the second embodiment of the present invention. [Figure 5] Figure 5 is a schematic plan view showing a stretchable device according to a third embodiment of the present invention. [Figure 6A] Figure 6A is a schematic plan view showing a modified example 1 of the stretchable device according to the third embodiment of the present invention. [Figure 6B] Figure 6B is a schematic cross-sectional view showing the structure between A and B in Figure 6A. [Figure 7A] Figure 7A is a schematic plan view showing a modified example 2 of the stretchable device according to the third embodiment of the present invention. [Figure 7B] Figure 7B is a schematic cross-sectional view showing the structure between B and C in Figure 7A. [Figure 8A] Figure 8A is a schematic plan view showing a modified example 3 of the stretchable device according to the third embodiment of the present invention. [Figure 8B] Figure 8B is a schematic cross-sectional view showing the structure between A and B in Figure 8A. [Figure 8C] Figure 8C is a schematic cross-sectional view showing the structure between B and C in Figure 8A. [Figure 9A]FIG. 9A is a plan view schematically showing a modification 4 of the stretchable device according to the third embodiment of the present invention. [Figure 9B] FIG. 9B is a cross-sectional view schematically showing the structure between A-A in FIG. 9A. [Figure 9C] FIG. 9C is a cross-sectional view schematically showing the structure between B-B in FIG. 9A. [Figure 10A] FIG. 10A is a plan view schematically showing a modification 5 of the stretchable device according to the third embodiment of the present invention. [Figure 10B] FIG. 10B is a cross-sectional view schematically showing the structure between A-A in FIG. 10A. [Figure 10C] FIG. 10C is a cross-sectional view schematically showing the structure between B-B in FIG. 10A. [Figure 11A] FIG. 11A is a plan view schematically showing a modification 6 of the stretchable device according to the third embodiment of the present invention. [Figure 11B] FIG. 11B is a cross-sectional view schematically showing the structure between A-A in FIG. 11A. [Figure 12A] FIG. 12A is a plan view schematically showing a modification 7 of the stretchable device according to the third embodiment of the present invention. [Figure 12B] FIG. 12B is a cross-sectional view schematically showing the structure between A-A in FIG. 12A. [[ID=²8]] [Figure 13A] FIG. 13A is a plan view schematically showing step 1 of the manufacturing method of the stretchable device according to the third embodiment of the present invention. <º000111>FIG. 13B is a plan view schematically showing step 2 of the manufacturing method of the stretchable device according to the third embodiment of the present invention. [Figure 13C] FIG. 13C is a plan view schematically showing step 3 of the manufacturing method of the stretchable device according to the third embodiment of the present invention. [Figure 13D] FIG. 13D is a plan view schematically showing step 4 of the manufacturing method of the stretchable device according to the third embodiment of the present invention. [Figure 13E] FIG. 13E is an enlarged plan view schematically showing step 5 of the manufacturing method of the stretchable device according to the third embodiment of the present invention. It should be noted that there is an unclear symbol "º" in the original text at line 32 which is retained as it is in the translation for the purpose of maintaining consistency with the original. If this is an error in the original, it may need to be corrected in the source material. [Modes for carrying out the invention]

[0009] The embodiments of the present invention will be described in detail below with reference to the drawings. In each embodiment, the differences from those described in previous embodiments will be mainly explained. In particular, similar effects and advantages due to similar configurations will not be mentioned sequentially in each embodiment. Among the components in the following embodiments, components not described in an independent claim will be described as optional components. Also, the sizes and size ratios of the components shown in the drawings are not necessarily precise. Furthermore, in each figure, substantially identical components are denoted by the same reference numerals, and redundant explanations may be omitted or simplified.

[0010] [First Embodiment] The configuration of the stretchable device 100 according to the first embodiment of the present invention will be described below with reference to Figure 1. Figure 1 is a schematic plan view showing a stretchable device according to one embodiment of the present invention.

[0011] A stretchable device 100 according to the first embodiment of the present invention comprises a stretchable substrate, a first stretchable wiring 20 disposed on the stretchable substrate, a second stretchable wiring 30 disposed on the first stretchable wiring 20, and an interlayer sheet 40 disposed between the first stretchable wiring 20 and the second stretchable wiring 30.

[0012] In this specification, "above" includes being located above an element at a distance, i.e., being located above an element via another object, being located above an element at a distance, and being located directly above an element in contact with it.

[0013] Therefore, in this specification, "first stretchable wiring 20 arranged on a stretchable substrate" includes the first stretchable wiring 20 in contact with the main surface of the stretchable substrate and the first stretchable wiring 20 in a state that is separated from the main surface of the stretchable substrate via other members (for example, a resin layer described later) without directly contacting the main surface of the stretchable substrate.

[0014] The resin layer may be formed from at least one resin material selected from the group consisting of, for example, polyimide-based, epoxy-based, urethane-based, and acrylic-based resins. Alternatively, the resin layer may be formed from an inorganic material such as alumina or silicon dioxide.

[0015] Furthermore, the stretchable substrate is a sheet-like or film-like stretchable substrate, and is composed of, for example, a stretchable resin material. Examples of resin materials for stretchable substrates include thermoplastic polyurethane (TPU), styrene-based elastomer, polyethylene (PE), polystyrene (PS), and polyethylene terephthalate (PET).

[0016] The thickness of the stretchable substrate is not particularly limited, but from the viewpoint of not hindering the stretching and contraction of the biological surface when attached to a living body, it is preferably 100 μm or less, and more preferably 50 μm or less. Furthermore, from the viewpoint of ensuring a certain level of strength, the thickness of the stretchable substrate is preferably 20 μm or more.

[0017] The first stretchable wiring 20 and the second stretchable wiring 30 each contain conductive particles and a resin. Examples of each stretchable wiring include a mixture of metal powder such as Ag, Cu, or Ni as conductive particles and an elastomer resin such as silicone resin. The average particle size of the conductive particles is not particularly limited, but is preferably 0.01 μm or more and 10 μm or less. Furthermore, the shape of the conductive particles is preferably spherical.

[0018] The thickness of each stretchable wire is not particularly limited, but is preferably 100 μm or less, and more preferably 50 μm or less. Furthermore, the thickness of each stretchable wire is preferably 0.01 μm or more. The line width of each stretchable wire is not particularly limited, but is preferably 0.1 μm or more, and more preferably 10 mm or less. Furthermore, the shape of each stretchable wire is not particularly limited.

[0019] Furthermore, the first expandable wiring 20 has a first electrode portion 21 and a first extension portion 22 extending from the first electrode portion 21 in a predetermined direction. The second expandable wiring 30 has a second electrode portion 31 and a second extension portion 32 extending from the second electrode portion 31 in a predetermined direction. In a plan view, the first electrode portion 21 and the second electrode portion 31 overlap each other. Also, the first extension portion 22 and the second extension portion 32 may extend in opposite directions. However, the first extension portion 22 and the second extension portion 32 may extend in the same direction.

[0020] In this embodiment, the first electrode portion 21 and the second electrode portion 31 may have the same size and shape in a plan view. The planar shape of each electrode portion may be, for example, a perfect circle, an ellipse, or a polygon.

[0021] However, without being limited to these, as will be described in the section on other embodiments later, the planar sizes of these components do not necessarily have to be the same. The first electrode portion 21 located on the lower layer side may be larger than the second electrode portion 31, and the stretchable substrate located on the lower layer side may be larger than the interlayer sheet. Furthermore, the planar shapes of these components do not necessarily have to be the same.

[0022] The interlayer sheet 40 includes a sheet portion 41 and at least one first via portion 42 provided on the sheet portion 41. For example, the interlayer sheet 40 may be made of the same material and thickness as the stretchable substrate described above. Also, in plan view, the stretchable substrate and the interlayer sheet may be the same size and shape. The planar shapes of the stretchable substrate and the interlayer sheet may be, for example, a rectangle, a square, a polygon, etc.

[0023] Based on the above configuration, the present invention is characterized in that the first via portion 42 partially has a connection region 43 that connects the first electrode portion 21 and the second electrode portion 31.

[0024] According to these features, the first via portion 42 has a non-connected region 44 in addition to the connection region 43 described above, which does not connect the first electrode portion 21 and the second electrode portion 31. That is, in a plan view (viewed from the thickness direction of the stretchable substrate), the second electrode portion 31 overlaps with a part of the first via portion 42.

[0025] From another perspective, in a plan view, the unconnected region 44 of the first via portion 42 is located outside the second electrode portion 31. From yet another perspective, in a plan view, the connected region 43 occupies a part of the first via portion 42.

[0026] As described above, in the present invention, the entire first via portion 42 is not composed of a connection region 43, but rather a part of the first via portion 42 constitutes a connection region 43, and the remaining portion constitutes a non-connection region 44 that does not connect the first electrode portion 21 and the second electrode portion 31.

[0027] Therefore, the position of the second electrode portion 31 is such that the connection region 43 and the non-connection region 44 are provided, and the positional relationship between the first via portion 42 and the second electrode portion 31 can be determined as a whole.

[0028] This allows for optimal positional accuracy between the first via portion 42 and the second electrode portion 31, and as a result, the reliability of the connection between the first electrode portion 21 of the first expandable wiring 20 located on the lower side and the second electrode portion 31 of the second expandable wiring located on the upper side can be improved.

[0029] Furthermore, in the stretchable device 100, since the entire device stretches and contracts, misalignment is likely to occur. However, even if misalignment occurs, the area where the unconnected region was located before the misalignment may become the connected region after the misalignment. Therefore, high connection reliability can be ensured even when the entire device stretches and contracts.

[0030] The stretchable device 100 may further have an adhesive layer. The adhesive layer has adhesive properties that allow the stretchable device 100 to be attached to a substrate such as a living organism. In one example, the adhesive layer may be positioned between the stretchable substrate and the substrate such as a living organism.

[0031] The adhesive layer comprises a first main surface on the side facing the object to be adhered, such as a living organism, and a second main surface on the opposite side. Preferably, the first adhesive layer has adhesive properties on both main surfaces. The first main surface of the adhesive layer can be attached to a living organism or the like. It is also possible for the first main surface of the adhesive layer itself to be attached to another layer, and then the other layer to be attached to a living organism or the like. The second main surface of the adhesive layer can be attached to a stretchable substrate. A protective layer may be further placed between the second main surface of the adhesive layer and the stretchable substrate from the viewpoint of improving waterproofing, etc.

[0032] As for the adhesive layer, any adhesive that is low-irritating to the skin, has sufficient pressure-sensitive adhesion, and can be easily peeled off the skin after use can be used without any particular restrictions.

[0033] While not particularly limited, the adhesive layer may consist of a pressure-sensitive adhesive. The pressure-sensitive adhesive is not particularly limited as long as it is generally usable for lamination on a stretchable substrate. For example, rubber-based, acrylic-based, or silicone-based pressure-sensitive adhesives can be used. When using a pressure-sensitive adhesive, adhesion to the mating component (stretchable substrate) can be achieved at relatively low temperatures, thus preventing deterioration and distortion of the stretchable substrate due to the use of excessive heat or UV energy.

[0034] [Second Embodiment] The configuration of the stretchable device 100A according to the second embodiment of the present invention will be described below with reference to Figure 2A. Figure 2A is a schematic plan view showing the stretchable device according to the second embodiment of the present invention.

[0035] The second embodiment differs from the first embodiment in that the interlayer sheet 40 includes a plurality of via portions 45.

[0036] Each via portion 45 has a smaller planar size than each electrode portion. Furthermore, the planar size of each via portion 45 is smaller than the width (short side dimension) of the extended portion of each wiring. Also, in a plan view, they can be regularly arranged at predetermined intervals on the sheet portion 41. An example of a regular arrangement is a matrix arrangement. That is, the interlayer sheet 40 has an assembly of via portions 45.

[0037] The planar shape of the via portion 45 can be, for example, a perfect circle, an ellipse, or a polygon. If the planar shape of the via portion 45 is circular, its diameter size D1 is, for example, 10 μm or more and 500 μm or less, and may be, for example, 50 μm or more and 300 μm or less, taking into account the ease of material filling. Also, if the aggregate of via portions 45 is arranged in a matrix, its length and width sizes D2 and D3 are, respectively, 2 mm or more and 20 mm or less, and may be, for example, 5 mm.

[0038] Furthermore, the multiple via portions 45 include a second via portion 46 and a third via portion 47, in addition to the first via portion 42 described in the first embodiment. There may be two or more of each of the first to third via portions. In the second embodiment, as in the first embodiment, as shown in Figure 2A, the first via portion 42 is a via portion that partially has a connecting region connecting the first electrode portion 21 and the second electrode portion 31. That is, the first via portion 42 is a via portion that partially overlaps the second electrode portion 31 in a plan view. In Figure 2A, the first via portion 42 corresponds to a via portion that is partially shaded in one via.

[0039] The second via portion 46 may be a via portion that, in a plan view, completely overlaps with the second electrode portion 31. In Figure 2A, the second via portion 46 corresponds to the via portion that is entirely shaded in one via. The second via portion 46 may be a via portion that, in a plan view, partially overlaps with the second electrode portion 31. Compared to the first via portion 42, the second via portion 46 consists of a connecting region that connects the first electrode portion 21 and the second electrode portion 31.

[0040] In other words, the second via portion 46 does not need to have a non-connected region that does not connect the first electrode portion 21 and the second electrode portion 31. Furthermore, the second via portion 46 is in contact with the second electrode portion 31 and is located below the second electrode portion 31. The presence of such a second via portion 46 can improve the reliability of the connection between the two electrode portions.

[0041] In this embodiment, Figure 2A and the corresponding Figure 3E (described later) show the second via portion located below the second electrode portion with a dotted line to improve understanding of its positional relationship and configuration. In other drawings of the expandable device having the second via portion, the second via portion located below the second electrode portion is not shown for the sake of readability.

[0042] The third via portion 47 is a via portion that does not overlap with the second electrode portion 31 in a plan view. In the second embodiment, the third via portion 47 may be a via hole. In Figure 2A, the third via portion 47 corresponds to the via portion of a single via that is not shaded.

[0043] As described above, the planar size of the via portion 45 is smaller than the planar size of each electrode portion. Therefore, in a plan view, multiple via portions 45, specifically the connection regions of multiple first via portions and multiple second via portions 46, can be positioned between the first electrode portion 21 and the second electrode portion 31.

[0044] As a result, multiple connection regions exist between the first electrode portion 21 and the second electrode portion 31, thereby improving the reliability of the connection between the first electrode portion 21 and the second electrode portion 31.

[0045] Even if, between the first electrode portion 21 and the second electrode portion 31, the proportion of the connection area in any of the multiple second via portions 46 is small, making it difficult to secure interlayer connection between the electrode portions in that portion, the presence of multiple other second via portions 46 allows for favorable interlayer connection between the electrode portions.

[0046] Furthermore, as described above, since the planar size of the via portion 45 is smaller than the width (short side dimension) of the extended portion of each wiring, it is possible to avoid fracture starting from the point where the second extended portion 32 of the second expandable wiring 30 overlaps with the edge of the via portion 45 in a plan view.

[0047] Furthermore, since there are multiple connection regions between the first electrode portion 21 and the second electrode portion 31 that connect these electrode portions, these multiple connection regions can provide an anchoring effect to the second electrode portion 31. This improves the adhesion between the second electrode portion 31 and the interlayer sheet 40 having multiple connection regions.

[0048] The following describes a method for manufacturing the stretchable device 100A according to the second embodiment described above.

[0049] Process 1 Figure 3A is a schematic plan view showing step 1 of the method for manufacturing a stretchable device according to the second embodiment of the present invention. First, as shown in Figure 3A, a stretchable base material 10 is prepared.

[0050] Process 2 Figure 3B is a schematic plan view showing step 2 of the method for manufacturing a stretchable device according to the second embodiment of the present invention. Next, as shown in Figure 3B, after performing step 1, the wiring material is screen printed onto the stretchable substrate 10 using a squeegee or the like, and then dried at approximately 100°C for a predetermined time. This allows the first stretchable wiring 20 to be formed on the stretchable substrate 10.

[0051] Process 3 Figure 3C is a schematic plan view showing step 3 of the method for manufacturing a stretchable device according to the second embodiment of the present invention. Next, as shown in Figure 3C, after performing step 2, a substrate 40a to be used as an interlayer sheet is prepared. This substrate 40a may be the same as the stretchable substrate 10 described above. Then, a laser is irradiated onto this substrate 40a at predetermined intervals to form via holes 45a having a regular arrangement such as a matrix arrangement. For example, a carbon dioxide laser can be used as the laser.

[0052] As described above, the planar shape of the via hole 45a can be, for example, a perfect circle, an ellipse, or a polygon. If the planar shape of the via hole 45a is circular, its diameter size D1 can be, for example, 10 μm to 500 μm. Also, if the aggregate of via holes 45a is arranged in a matrix, its lengthwise and widthwise sizes D2 and D3 can be, respectively, 2 mm to 20 mm.

[0053] Process 4 Figure 3D is a schematic plan view showing step 4 of the method for manufacturing a stretchable device according to the second embodiment of the present invention. Next, as shown in Figure 3D, after performing step 3, the base material 40a prepared in step 3 is joined to the stretchable base material 10 with the first stretchable wiring 20. As a joining means, for example, dry lamination using a vacuum press can be used.

[0054] Process 5 Figure 3E is a schematic plan view showing step 5 of the method for manufacturing a stretchable device according to the second embodiment of the present invention. Next, as shown in Figure 3E, after performing step 4, similar to step 2, a squeegee or the like is used to screen print wiring material onto predetermined locations on the substrate 40a, which serves as an interlayer sheet, so that it can be interlayer connected to the first electrode portion 21 of the first stretchable wiring 20 through the via holes 45a. After that, it is dried at approximately 100°C for a predetermined time. This allows the second stretchable wiring 30 to be formed on the obtained interlayer sheet 40.

[0055] In this specification, through holes formed in the substrate 40a during the manufacturing process are referred to as via holes 45a, while those formed at the completion stage are referred to as via portions 45. This distinction in terminology is based on the fact that, as previously described, the multiple via portions 45 obtained include a first via portion 42 (partially filled with wiring material), a second via portion 46 (fully filled with wiring material), and a third via portion (not filled with wiring material and remaining in the state of via holes).

[0056] Based on the above, the stretchable device 100A according to the second embodiment can be manufactured.

[0057] [Modified version of the second embodiment] The configuration of a modified example of the stretchable device according to the second embodiment of the present invention will be described below with reference to Figure 2B. Figure 2B is a schematic plan view showing a modified example of the stretchable device according to the second embodiment of the present invention.

[0058] A modified version of the second embodiment differs from the second embodiment in that the via portion 45 already contains a conductive material 48 inside. The conductive material may be the same as the wiring material described above. The fact that the conductive material is provided in advance within the via portion 45 means that, in the stage before forming the second expandable wiring, the conductive material is provided in advance not only in the portion that will become the third via portion but also in the portion that will become the second via portion that may overlap with the second electrode portion. In Figure 2B, the formed third via portion 47 corresponds to a via portion that is diagonally cut in a different direction overall compared to the second via portion 46 shown in Figure 2A, within a single via portion.

[0059] This makes it possible to avoid the occurrence of insufficient filling of the wiring material (corresponding to conductive material) into the via portion. Furthermore, it becomes easier to detect such insufficient filling of the material. In addition, conductive material does not need to be provided in advance in the portion that may become the first via portion before forming the second stretchable wiring.

[0060] The following describes the method for manufacturing the stretchable device 100B (a modified example of the second embodiment) according to the second embodiment described above. Note that any parts that overlap with those described in the section on the manufacturing method of the stretchable device 100A will be omitted or simplified.

[0061] Process 1 Figure 4A is a schematic plan view showing step 1 of the method for manufacturing a modified example of the stretchable device according to the second embodiment of the present invention. First, as shown in Figure 4A, a stretchable base material 10 is prepared.

[0062] Process 2 Figure 4B is a schematic plan view showing step 2 of the method for manufacturing a modified example of the stretchable device according to the second embodiment of the present invention. Next, as shown in Figure 4B, after performing step 1, the wiring material is screen printed onto the stretchable substrate 10 and then dried. This allows the first stretchable wiring 20 to be formed on the stretchable substrate 10.

[0063] Process 3 Figure 4C is a schematic plan view showing step 3 of the method for manufacturing a modified example of a stretchable device according to the second embodiment of the present invention. Next, as shown in Figure 4C, after performing step 2, a substrate 40a to be used as an interlayer sheet is prepared. Then, a plurality of via holes 45a having a regular arrangement are formed by irradiating the substrate 40a with a laser at predetermined intervals. Furthermore, conductive material is then filled into predetermined locations of the plurality of via holes 45a. As a filling means, for example, conductive material can be filled into the via holes by using screen printing. As for the filling locations, conductive material is pre-filled into at least the portions that will become the third via portion and the portions that will become the second via portion in the final device.

[0064] Process 4 Figure 4D is a schematic plan view showing step 4 of the method for manufacturing a modified example of the stretchable device according to the second embodiment of the present invention. Next, as shown in Figure 4D, after performing step 3, the base material 40a prepared in that step is joined to the stretchable base material 10 with the first stretchable wiring 20. After joining the base material 40a, conductive material may be filled into predetermined locations of the multiple via holes 45a.

[0065] Process 5 Figure 4E is a schematic plan view showing step 5 of the method for manufacturing a modified example of the stretchable device according to the second embodiment of the present invention. Next, as shown in Figure 4E, after performing step 4, the wiring material is screen printed on predetermined locations of the substrate 40a, which serves as an interlayer sheet, so that it can be interlayer connected to the first electrode portion 21 of the first stretchable wiring 20 through via holes 45a, similar to step 2. Then, it is dried. This allows the second stretchable wiring 30 to be formed on the obtained interlayer sheet 40.

[0066] Based on the above, the stretchable device 100B according to the second embodiment can be manufactured.

[0067] [Third Embodiment] The configuration of the stretchable device 100C according to the third embodiment of the present invention will be described below with reference to Figure 5. Figure 5 is a schematic plan view showing the stretchable device according to the third embodiment of the present invention.

[0068] The stretchable device 100C in the third embodiment has basically the same configuration as in the first embodiment. One difference from the first embodiment is that, as shown in Figure 5, for example, the planar size of the second electrode portion 31C of the second stretchable wiring 30C is smaller than the planar size of the first electrode portion 21C of the first stretchable wiring 20C.

[0069] In this case as well, similar to the first embodiment, a portion of the first via portion 42 constitutes a connection region 43, and the remaining portion constitutes a non-connection region 44 that does not connect the first electrode portion 21C and the second electrode portion 31C. Therefore, the position of the second electrode portion 31C is such that the connection region 43 and the non-connection region 44 are provided, and the positional relationship between the first via portion 42 and the second electrode portion 31C can be determined as a whole.

[0070] This allows for optimal positional accuracy between the first via portion 42 and the second electrode portion 31C, and as a result, the connection reliability between the first electrode portion 21C of the first expandable wiring 20C located on the lower side and the second electrode portion 31C of the second expandable wiring 30C located on the upper side can be improved.

[0071] Furthermore, in the final stretchable device, a portion of the first via portion 42 constitutes a connection region 43, and the remaining portion constitutes a non-connection region 44 that does not connect the first electrode portion 21C and the second electrode portion 31C. To achieve this, when forming the second stretchable wiring during the fabrication of the stretchable device, the wiring material is formed so as not to cover or overlap the entire via hole in a plan view. This ensures an escape route for air located in the via hole, and suppresses the occurrence of residual air bubbles (also called streaking) in the via portion including the connection region 43 made of the resulting wiring material (corresponding to conductive material).

[0072] [Modification 1 of the third embodiment] The configuration of Modified Example 1 of the stretchable device according to the third embodiment of the present invention will be described below with reference to Figures 6A and 6B.

[0073] Figure 6A is a schematic plan view showing a modified example 1 of the stretchable device according to the third embodiment of the present invention. Figure 6B is a schematic cross-sectional view showing the structure between A and B in Figure 6A.

[0074] Modification 1 is characterized in that, in a plan view, the unconnected region 44D of the first via portion 42D extends from the second electrode portion 31D toward the edge portion 41DI of the interlayer sheet 40D. Also, as shown in the figure, each of the first stretchable wiring 20D and the second stretchable wiring 30D has two or more electrode portions 21D, 31D.

[0075] With these features, the orientation of the non-connected region 44D of the first via portion 42D can be consistently directed. Furthermore, it becomes easier to ensure sufficient size of the non-connected region 44D between the electrode portion and the edge portion 41DI of the interlayer sheet 40D. As a result, the positional relationship between the first via portion 42D and the second electrode portion 31D can be made clearer. This allows for more favorable positional accuracy between the first via portion 42D and the second electrode portion 31D.

[0076] Furthermore, during the formation of the second stretchable wiring 30D in the process of fabricating the stretchable device 100D, it becomes easier to secure an escape route for air located in the via hole, and the occurrence of residual air bubbles in the via portion including the connection region 43D made of the resulting wiring material (corresponding to conductive material) can be further suppressed.

[0077] [Modification 2 of the third embodiment] The configuration of a modified example 2 of the stretchable device according to the third embodiment of the present invention will be described below with reference to Figures 7A and 7B.

[0078] Figure 7A is a schematic plan view showing a modified example 2 of the stretchable device according to the third embodiment of the present invention. Figure 7B is a schematic cross-sectional view showing the structure between B and C in Figure 7A.

[0079] Modification 2 is characterized in that, in a plan view, the unconnected region 44E of the first via portion 42E is continuous from the second electrode portion 31E to the edge portion 41EI of the interlayer sheet 40E.

[0080] According to these features, the interlayer sheet 40E is partially divided starting from the non-connected region 44E of the first via portion 42E. As a result, when an expansion and contraction force acts in the direction of the arrow shown in Figure 7A, the expansion and contraction force is less likely to act on the expansion and contraction wiring located in the central part of the expansion and contraction device 100E in a plan view. This suppresses the expansion and contraction of the wiring and reduces changes in wiring resistance. In addition, when forming vias in this area, less cutting debris remains in the via portion. Therefore, it becomes easier to ensure that the size of the via portion is the predetermined size.

[0081] [Modification 3 of the third embodiment] The configuration of a modified example 3 of the stretchable device according to the third embodiment of the present invention will be described below with reference to Figures 8A to 8C.

[0082] Figure 8A is a schematic plan view showing a modified example 3 of the stretchable device according to the third embodiment of the present invention. Figure 8B is a schematic cross-sectional view showing the structure between A and A in Figure 8A. Figure 8C is a schematic cross-sectional view showing the structure between B and C in Figure 8A.

[0083] Modification 3 is characterized in that, in a plan view, the edge 41FI of the interlayer sheet 40F is located inside the edge 10FI of the stretchable substrate 10F. With this feature, the planar size of the interlayer sheet 40F is smaller than the planar size of the stretchable substrate 10F, so high-precision bonding is not required when bonding the interlayer sheet 40F to the stretchable substrate 10F, which is preferable in terms of manufacturing efficiency. Furthermore, in the stretchable device, even if there is external contact in the longitudinal direction of the substrate, direct contact of the interlayer sheet 40F can be avoided.

[0084] [Modification 4 of the third embodiment] The configuration of a modified example 4 of the stretchable device according to the third embodiment of the present invention will be described below with reference to Figures 9A to 9C.

[0085] Figure 9A is a schematic plan view showing a modified example 4 of the stretchable device according to the third embodiment of the present invention. Figure 9B is a schematic cross-sectional view showing the structure between A and A in Figure 9A. Figure 9C is a schematic cross-sectional view showing the structure between B and C in Figure 9A.

[0086] Modified example 4 is characterized in that three or more stretchable wirings are arranged in the thickness direction of the stretchable substrate 10G, and the electrode portions of adjacent stretchable wirings are interconnected through the first via portion 42G of the interlayer sheet 40G.

[0087] As an example, as shown in the figure, the stretchable device 100G has a first stretchable wiring 20G, a second stretchable wiring 30G, and a third stretchable wiring 50G positioned between the first stretchable wiring 20G and the second stretchable wiring 30G in the thickness direction of the stretchable substrate 10.

[0088] According to these features, even when three or more expandable wirings are arranged, a portion of the first via portion 42G constitutes a connection region 43G between two adjacent expandable wirings, while the remaining portion constitutes a non-connection region 44G that does not connect the first electrode portion 21G and the second electrode portion 31G. Therefore, the positional relationship between the first via portion 42G and the second electrode portion 31G can be determined as a whole. This makes it possible to suitably ensure positional accuracy between the first via portion 42G and the second electrode portion 31G.

[0089] Furthermore, when forming the upper of two adjacent stretchable wirings during the fabrication of a stretchable device, the wiring material is formed so as not to cover or overlap the entire via hole in a plan view. This ensures an escape route for air located in the via hole, and suppresses the occurrence of residual air bubbles (also called streaking) in the via portion, including the connection region 43G made of the resulting wiring material (corresponding to conductive material).

[0090] [Modification 5 of the third embodiment] The configuration of modified example 5 of the stretchable device according to the third embodiment of the present invention will be described below with reference to Figures 10A to 10C.

[0091] Figure 10A is a schematic plan view showing a modified example 5 of the stretchable device according to the third embodiment of the present invention. Figure 10B is a schematic cross-sectional view showing the structure between A and A in Figure 10A. Figure 10C is a schematic cross-sectional view showing the structure between B and C in Figure 10A.

[0092] Modification 5 is characterized in that, compared to Modification 4, two or more first via portions 42H are provided, in which the non-connected regions 44H are offset from each other in a plan view.

[0093] Since no wiring material or conductive material exists in the non-connected region 44H of the first via portion 42H, when three or more stretchable wirings are arranged in the thickness direction of the stretchable substrate 10H, if the non-connected regions 44H of two or more first via portions 42H overlap each other in a plan view, the thickness of the interlayer sheet in the local region tends to be non-uniform compared to the thickness of other regions.

[0094] In this regard, according to the above features, in a plan view, the non-connected regions 44H of each of the two or more first via portions 42H are in a positional relationship that is offset from each other, so it is possible to suppress the non-uniformity of the thickness of the interlayer sheet in local regions compared to the thickness of other regions.

[0095] [Modification 6 of the third embodiment] The configuration of a modified example 6 of the stretchable device according to the third embodiment of the present invention will be described below with reference to Figures 11A and 11B.

[0096] Figure 11A is a schematic plan view showing a modified example 6 of the stretchable device according to the third embodiment of the present invention. Figure 11B is a schematic cross-sectional view showing the structure between A and B in Figure 11A.

[0097] Modification 6 is characterized in that, in a plan view, a plurality of first via portions 42I are located below a single first electrode portion 31I.

[0098] With these features, the presence of multiple first via portions 42I allows for a larger connection area 43I compared to the case of a single via. This further improves the reliability of the interlayer connection. Furthermore, when fabricating a stretchable device, it reduces the required precision for alignment when joining the interlayer sheet 40I to the stretchable substrate 10I, and the required precision for the position of the second stretchable wiring formed at predetermined locations on the interlayer sheet 40I.

[0099] [Modification 7 of the third embodiment] The configuration of modified example 7 of the stretchable device according to the third embodiment of the present invention will be described below with reference to Figures 12A and 12B.

[0100] Figure 12A is a schematic plan view showing a modified example 7 of the stretchable device according to the third embodiment of the present invention. Figure 12B is a schematic cross-sectional view showing the structure between A and A in Figure 12A.

[0101] Note that Figure 12A primarily emphasizes the arrangement and structure of the multiple internal expandable wirings located between the first expandable wiring 20J and the second expandable wiring 30J, for the sake of readability. In other words, the second expandable wiring is omitted from the illustration in Figure 12A.

[0102] Modification 7 is the same as Modification 4 in that three or more stretchable wirings are arranged in the thickness direction of the stretchable substrate 10J, but the internal stretchable wirings 70J and 80J located between the first stretchable wiring 20J and the second stretchable wiring 30J are located in multiple positions in the longitudinal direction of the interlayer sheet 40J.

[0103] In one example, in the thickness direction of the stretchable substrate 10J, two stretchable wirings 20J and 30J with a large area are placed between two stretchable wirings 70J and 80J with a smaller area inside the device. These stretchable wirings 70J and 80J can be arranged in parallel at predetermined intervals on the interlayer sheet 40J.

[0104] Some of the stretchable wiring 70J is interlayer-connected to the first stretchable wiring 20J and the second stretchable wiring 30J via the connection areas of the via portions, respectively. On the other hand, the remaining stretchable wiring 80J is not connected to the first stretchable wiring 20J and the second stretchable wiring 30J and functions as a separate, independent wiring. In other words, the remaining stretchable wiring 80J located inside functions as stretchable wiring that does not come into contact with the first via portion 42J.

[0105] With these features, the first and second stretchable wirings can block noise that could penetrate the internal stretchable wiring. Furthermore, since a single stretchable device 100J can be provided with two or more types of wiring or wiring groups having different functions, it is advantageous in that it can enrich the device's functionality.

[0106] The following describes the method for manufacturing the stretchable device 100C according to the third embodiment (basic mode) shown in Figure 5 above. Note that any parts of the description that overlap with the previously mentioned method for manufacturing the stretchable device will be omitted or simplified.

[0107] Process 1 Figure 13A is a schematic plan view showing step 1 of the method for manufacturing a stretchable device according to the third embodiment of the present invention. First, as shown in Figure 13A, a stretchable base material 10 is prepared.

[0108] Process 2 Figure 13B is a schematic plan view showing step 2 of the method for manufacturing a stretchable device according to the third embodiment of the present invention. Next, as shown in Figure 13B, after performing step 1, the wiring material is screen printed onto the stretchable substrate 10 and then dried. This allows the first stretchable wiring 20 to be formed on the stretchable substrate 10.

[0109] Process 3 Figure 13C is a schematic plan view showing step 3 of the method for manufacturing a stretchable device according to the third embodiment of the present invention. Next, as shown in Figure 13C, after performing step 2, a substrate 40b to be used as an interlayer sheet is prepared. Then, a laser is irradiated onto this substrate 40b to form via holes 45b.

[0110] Process 4 Figure 13D is a schematic plan view showing step 4 of the method for manufacturing a stretchable device according to the third embodiment of the present invention. Next, as shown in Figure 13D, after performing step 3, the base material 40b prepared in that step is joined to the stretchable base material 10 with the first stretchable wiring 20.

[0111] Process 5 Figure 13E is a schematic plan view showing step 5 of the method for manufacturing a stretchable device according to the third embodiment of the present invention. Next, as shown in Figure 13E, after performing step 4, similar to step 2, the wiring material is screen printed using a squeegee at predetermined locations on the substrate 40b, which serves as an interlayer sheet, so that it can be interlayer connected to the first electrode portion 21C of the first stretchable wiring 20C through via holes 45b. After that, it is dried. This allows the second stretchable wiring 30C to be formed on the obtained interlayer sheet 40.

[0112] Specifically, in this manufacturing method, in step 5, the wiring material is printed and applied so as not to cover or overlap the entire via hole in a plan view, such that in the stretchable device finally obtained, a part of the first via portion 42 constitutes a connection area 43, and the remaining portion constitutes a non-connection area 44 that does not connect the first electrode portion 21C and the second electrode portion 31C.

[0113] This ensures an escape route for air located at the via hole, and suppresses the occurrence of residual air bubbles (also called streaking) in the via portion including the connection area 43 made of the resulting wiring material (corresponding to conductive material).

[0114] Based on the above, the stretchable device 100C according to the third embodiment can be manufactured.

[0115] Furthermore, the embodiments and modifications shown are illustrative, and the present invention is not limited to these embodiments and modifications. Also, the drawings are illustrative of the components and do not limit their shape. Additionally, partial substitution or combination of the configurations shown in different embodiments and modifications is possible.

[0116] The stretchable device according to one embodiment of the present invention may take the following forms. <1> The invention comprises a stretchable substrate, a first stretchable wiring disposed on the stretchable substrate and having a first electrode portion, a second stretchable wiring disposed on the first stretchable wiring and having a second electrode portion, and an interlayer sheet disposed between the first stretchable wiring and the second stretchable wiring. The interlayer sheet includes a sheet portion and at least one first via portion provided in the sheet portion. The first via portion is a stretchable device having a connection region that connects the first electrode portion and the second electrode portion. <2> In a plan view, the second electrode portion overlaps with a part of the first via portion. <1> The stretchable device described. <3> The first via portion further includes, in addition to the connection region, a non-connected region that does not connect the first electrode portion and the second electrode portion. <1> or <2> The stretchable device described. <4> In a plan view, the disconnected region of the first via portion is located outside the second electrode portion. <3> The stretchable device described. <5> In a plan view, the connection region occupies a portion of the first via portion. <1> ~ <4> A stretchable device as described in any of the following. <6> In a plan view, the interlayer sheet further has at least one second via portion that overlaps overall with the second electrode portion. <1> ~ <5> A stretchable device as described in any of the following. <7> The second via portion comprises the connection region, <6> The stretchable device described. <8> In a plan view, the interlayer sheet further has a third via portion that does not overlap with the second electrode portion. <1> ~ <7> A stretchable device as described in any of the following. <9> The interlayer sheet has a plurality of via portions that are regularly arranged at predetermined intervals in the sheet portion, and the plurality of via portions include the first via portion and the second via portion. <6> or <7> The stretchable device described. <10> The plurality of via portions are arranged in a matrix. <9> The stretchable device described. <11> The diameters of the plurality of via portions are smaller than the diameters of the first electrode portion and the second electrode portion. <9> or <10> The stretchable device described. <12> The third via portion is a via hole or a via portion having a conductive material inside. <8> The stretchable device described. <13> In a plan view, the disconnected region of the first via portion extends from the second electrode portion toward the edge of the interlayer sheet. <3> ~ <5> A stretchable device as described in any of the following. <14> In a plan view, the disconnected region of the first via portion is continuous from the second electrode portion to the edge of the interlayer sheet. <13> The stretchable device described. <15> In a plan view, the edge of the interlayer sheet is located inside the edge of the stretchable base material. <13> The stretchable device described. <16> Three or more of the stretchable wirings are arranged in the thickness direction of the stretchable substrate, and the electrode portion of one adjacent stretchable wiring and the electrode portion of the other stretchable wiring are interconnected through the first via portion of the interlayer sheet. <1> ~ <5> A stretchable device as described in any of the following. <17> When three or more of the aforementioned expandable wirings are arranged, two or more of the aforementioned first via portions are provided such that the non-connected regions are offset from each other in a plan view. <16> The stretchable device described. <18> When three or more of the aforementioned expandable wirings are arranged, the expandable wirings have some that do not come into contact with the first via portion. <16> or <17> The stretchable device described. <19> When three or more of the aforementioned stretchable wirings are arranged, in the thickness direction of the stretchable substrate, a stretchable wiring with a smaller area is arranged between two stretchable wirings with a larger area. <16> ~ <18> A stretchable device as described in any of the following. <20> The aforementioned small area of ​​expandable wiring is arranged in parallel on the interlayer sheet at predetermined intervals. <19> The stretchable device described.

[0117] 100, 100A~100J: Stretchable device 10, 10A~10J: Stretchable base material 20, 20C~20J: First stretchable wiring 21, 21C~21I: First electrode section 22, 22C~22G: First extension 30, 30C~30J: Second type of stretchable wiring 31, 31C~31I: Second electrode section 32, 32C~32H: Second extension 40, 40D~40G, 40I, 40J: Interlayer sheets 40a, 40b: Base material 41, 41D~41J: Seat portion 41DI~41FI: Edge portion of the interlayer sheet 42, 42D~42I: First via section 43, 43D~43I: Connection area 44, 44D~44F: Disconnected area 45: Beer section 45a, 45b: Via holes 46: Second via section 47: Third beer section 48: Conductive material 50G, 50H Third-generation stretchable wiring 51G, 51H Electrode portion of the third stretchable wiring 60G, 60H, 60J protective layer 70J, 80J Internal stretchable wiring 71J Internal expandable wiring electrode section 72J Extension of internal stretchable wiring

Claims

1. The device comprises a stretchable base material, a first stretchable wiring disposed on the stretchable base material and having a first electrode portion, a second stretchable wiring disposed on the first stretchable wiring and having a second electrode portion, and an interlayer sheet disposed between the first stretchable wiring and the second stretchable wiring. The interlayer sheet includes a sheet portion and at least one first via portion provided in the sheet portion. The first via portion has a connection area that partially connects the first electrode portion and the second electrode portion, making it a stretchable device.

2. The expandable device according to claim 1, wherein, in a plan view, the second electrode portion overlaps with a portion of the first via portion.

3. The stretchable device according to claim 1 or 2, wherein the first via portion further has, in addition to the connection region, a non-connected region that does not connect the first electrode portion and the second electrode portion.

4. The expandable device according to claim 3, wherein, in a plan view, the unconnected region of the first via portion is located outside the second electrode portion.

5. The expandable device according to claim 1, wherein, in a plan view, the connection region occupies a portion of the first via portion.

6. The stretchable device according to claim 1, wherein, in a plan view, the interlayer sheet further has at least one second via portion that overlaps overall with the second electrode portion.

7. The expandable device according to claim 6, wherein the second via portion comprises the connection region.

8. The stretchable device according to claim 1, wherein, in a plan view, the interlayer sheet further has a third via portion that does not overlap with the second electrode portion.

9. The stretchable device according to claim 6, wherein the interlayer sheet has a plurality of via portions regularly arranged at predetermined intervals in the sheet portion, and the plurality of via portions include the first via portion and the second via portion.

10. The expandable device according to claim 9, wherein the plurality of via portions are arranged in a matrix.

11. The expandable device according to claim 9, wherein the diameter of the plurality of via portions is smaller than the diameter of the first electrode portion and the second electrode portion.

12. The expandable device according to claim 8, wherein the third via portion is a via hole or a via portion having a conductive material inside.

13. The stretchable device according to claim 3, wherein, in a plan view, the unconnected region of the first via portion extends from the second electrode portion toward the edge of the interlayer sheet.

14. The stretchable device according to claim 13, wherein, in a plan view, the unconnected region of the first via portion is continuous from the second electrode portion to the edge of the interlayer sheet.

15. The stretchable device according to claim 13, wherein, in a plan view, the edge of the interlayer sheet is located inward from the edge of the stretchable base material.

16. The stretchable device according to claim 1, wherein three or more stretchable wirings are arranged in the thickness direction of the stretchable substrate, and the electrode portion of one adjacent stretchable wiring and the electrode portion of the other stretchable wiring are interconnected through the first via portion of the interlayer sheet.

17. Three or more of the stretchable wirings are arranged in the thickness direction of the stretchable substrate, and the electrode portion of one adjacent stretchable wiring and the electrode portion of the other stretchable wiring are connected to each other through the first via portion of the interlayer sheet, The expandable device according to claim 3, wherein, when three or more of the expandable wirings are arranged, two or more of the first via portions are provided such that the non-connected regions are offset from each other in a plan view.

18. The stretchable device according to claim 16, wherein, when three or more of the stretchable wirings are arranged, the stretchable wirings do not come into contact with the first via portion.

19. The stretchable device according to claim 16, wherein, when three or more of the stretchable wirings are arranged, a stretchable wiring with a smaller area is arranged between two stretchable wirings with a larger area in the thickness direction of the stretchable substrate.

20. The stretchable device according to claim 19, wherein the stretchable wiring with a small area is arranged in parallel at predetermined intervals on the interlayer sheet.

Images