Method for manufacturing device

Abstract

This method for manufacturing a device includes: a first step for preparing a wiring board including an insulating base material having flexibility and a conductive layer formed on the insulating base material; and a second step for covering an object with the wiring board by deforming the wiring board along the three-dimensional shape of the object. The wiring board includes a first surface and a second surface positioned on opposite sides of each other, and a folding structure in which a plurality of folding lines that extend along a first axis with a wave shape of a curve in plan view are arrayed along a second axis intersecting the first axis. Each of the first surface and the second surface includes a plurality of ridge lines and a plurality of valley lines. Each of the plurality of folding lines corresponds to any one of the plurality of ridge lines on the first surface and any one of the plurality of valley lines on the second surface, or any one of a plurality of valley lines on the first surface and any one of the plurality of ridge lines on the second surface.

Description

Device manufacturing method

[0001] The present disclosure relates to a method for manufacturing a device that uses a wiring substrate.

[0002] Flexible substrates, in which a plurality of wiring lines are formed on a flexible insulating substrate, are used in a wide range of devices such as electronic devices and electric devices. For example, Patent Document 1 discloses a flexible substrate that can be bent three-dimensionally.

[0003] Japanese Patent Application Laid-Open No. 2021-150585

[0004] In the technology of Patent Document 1, the bend lines of the insulating substrate are configured as straight lines (e.g., fold lines) in a plan view. Therefore, for example, in the process of deforming the flexible substrate, local stress acts on the wiring, which may result in breakage, buckling, or other damage. In consideration of the above circumstances, one aspect of the present disclosure aims to suppress breakage, such as breakage, buckling, or other damage to the conductive layer of the wiring substrate.

[0005] In order to solve the above problems, a manufacturing method of a device according to one aspect of the present disclosure includes a first step of preparing a wiring board having a flexible insulating base material and a conductive layer formed on the insulating base material, and a second step of covering an object with the wiring board by deforming the wiring board to conform to the three-dimensional shape of the object, wherein the wiring board includes a first surface and a second surface located opposite each other, and a folded structure in which a plurality of folding lines extending along a first axis in a curved wave shape in a planar view are arranged along a second axis intersecting the first axis, and each of the first surface and the second surface includes a plurality of ridge lines and a plurality of valley lines, and each of the plurality of folding lines corresponds to one of the plurality of ridge lines on the first surface and one of the plurality of valley lines on the second surface, or to one of the plurality of valley lines on the first surface and one of the plurality of ridge lines on the second surface.

[0006] A method for manufacturing a device according to another aspect of the present disclosure includes a first step of preparing a flexible resin film and a second step of covering an object with the resin film by deforming the resin film to conform to the three-dimensional shape of the object, wherein the resin film includes a first surface and a second surface located opposite each other, and a folded structure in which a plurality of fold lines extending along a first axis in a curved wave shape in a planar view are arranged along a second axis intersecting the first axis, each of the first surface and the second surface including a plurality of ridge lines and a plurality of valley lines, each of the plurality of fold lines corresponding to one of the plurality of ridge lines on the first surface and one of the plurality of valley lines on the second surface, or one of the plurality of valley lines on the first surface and one of the plurality of ridge lines on the second surface.

[0007] 1 is a perspective view of a device according to a first embodiment. FIG. 2 is a plan view of a wiring board. FIG. 3 is a cross-sectional view of a wiring board. FIG. 4 is an enlarged plan view of a portion of the wiring board. FIG. 5 is a plan view in which the unevenness of the surface of the wiring board is expressed by shading. FIG. 6 is a cross-sectional view taken along line VI-VI in FIGS. 4 and 5. FIG. 7 is a cross-sectional view taken along line VII-VII in FIGS. 4 and 5. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIGS. 4 and 5. FIG. 9 is a cross-sectional view taken along line IX-IX in FIGS. 4 and 5. FIG. 10 is a plan view of a wiring board according to a modified example of the first embodiment. FIG. 11 is a plan view of a wiring board according to a modified example of the first embodiment. FIG. 12 is a plan view of a wiring board according to a modified example of the first embodiment. FIG. 13 is a plan view of a wiring board according to a modified example of the first embodiment. FIG. 14 is a plan view of a wiring board according to a modified example of the second embodiment. FIG. 15 is an enlarged plan view of a portion of a wiring board according to a second embodiment. FIG. 16 is an explanatory diagram of a test for evaluating the flexibility of a wiring board. FIG. 17 is a result of evaluating the flexibility of a wiring board. FIG. 18 is an enlarged plan view of a portion of a wiring board according to test sample 1. FIG. 19 is an enlarged plan view of a portion of a wiring board according to test sample 2. FIG. 19 is an enlarged plan view of a portion of a wiring board according to a modified example of the second embodiment. FIG. 20 is a flowchart of a procedure for manufacturing a device according to a third embodiment. 32. An explanatory diagram of a molding process in the third embodiment. An explanatory diagram of a molding process in the fourth embodiment. A cross-sectional view of a wiring board in the fifth embodiment. A configuration diagram of an articulation mechanism in the sixth embodiment. A configuration diagram of a rotation mechanism in the seventh embodiment. A configuration diagram of a wiring structure in the eighth embodiment. A cross-sectional view of a wiring board in a modified example. A plan view of a wiring board in a modified example. A plan view of a wiring board in a modified example. A perspective view of a device in a modified example. A plan view of a wiring board in a modified example. A cross-sectional view along the XXX-XXX line in FIG. 32. A perspective view of a device in a modified example. A cross-sectional view of a wiring board ... graph showing elastic properties of a wiring board.

[0008] The embodiments for carrying out the present disclosure will be described with reference to the drawings. Note that the dimensions and scale of each element in each drawing may differ from those of the actual product. Furthermore, the embodiment described below is an exemplary embodiment that may be envisioned when carrying out the present disclosure. Therefore, the scope of the present disclosure is not limited to the embodiment exemplified below.

[0009] A: First Embodiment Fig. 1 is a perspective view of an apparatus 100 that uses a wiring board 20 according to a first embodiment. As illustrated in Fig. 1, the apparatus 100 includes an object 10 and a wiring board 20. The object 10 is any structure on which the wiring board 20 is to be mounted. Although Fig. 1 illustrates an example of a rectangular parallelepiped object 10, the shape or size of the object 10 is arbitrary. Furthermore, the wiring board 20 is mounted on the object 10 for any purpose.

[0010] The wiring board 20 is a film-like (e.g., thin plate-like or sheet-like) mounting component that is mounted on the object 10. The wiring board 20 is deformable so as to cover the object 10. That is, the wiring board 20 covers the surface of the object 10 by deforming to follow the three-dimensional shape of the object 10. As described above, the device 100 is an article (e.g., an electronic device or an electric device) in which the object 10 is covered with the wiring board 20.

[0011] Fig. 2 is a plan view of the wiring board 20. Fig. 2 shows the wiring board 20 in an undeformed state before mounting. Fig. 3 is a cross-sectional view of the wiring board 20.

[0012] In the following description, three mutually orthogonal axes (X-axis, Y-axis, and Z-axis) are assumed, as illustrated in Figures 2 and 3. Furthermore, one direction along the X-axis will be referred to as the "X1 direction," and the direction opposite to the X1 direction will be referred to as the "X2 direction." Similarly, one direction along the Y-axis will be referred to as the "Y1 direction," and the direction opposite to the Y1 direction will be referred to as the "Y2 direction." The X-axis is an example of a "first axis," and the Y-axis is an example of a "second axis."

[0013] One direction along the Z axis is referred to as the "Z1 direction," and the opposite direction to the Z1 direction is referred to as the "Z2 direction." Figure 3 shows a cross section of the wiring board 20 along the Z axis. In the following description, observing an object from a line of sight along the Z axis is referred to as a "planar view."

[0014] The wiring board 20 is a film-like flexible printed circuit (FPC) that extends along the X-Y plane. The wiring board 20 includes a first surface F1 and a second surface F2. The first surface F1 and the second surface F2 are main surfaces that are located on opposite sides of the wiring board 20. The first surface F1 and the second surface F2 are planes that extend along the X-Y plane. As can be understood from the above description, the Z axis (Z1 direction or Z2 direction) can also be expressed as an axis that is perpendicular to the first surface F1 or the second surface F2.

[0015] As illustrated in FIG. 3 , the wiring substrate 20 is a laminate including an insulating substrate 21, an insulating substrate 22, and a conductive layer 23. The insulating substrate 21 and the insulating substrate 22 are flexible and insulating film-like substrates. Specifically, the insulating substrate 21 and the insulating substrate 22 are formed from an elastically deformable insulating material. The main material of the insulating substrate 21 and the insulating substrate 22 is a resin material such as polyimide (PI), polyester (PET), polyethylene naphthalate (PEN), or liquid crystal polymer (LCP). That is, the insulating substrate 21 and the insulating substrate 22 constitute a resin film. However, the materials of the insulating substrate 21 and the insulating substrate 22 are not limited to the above examples and may be changed as desired. Note that flexibility refers to the ability to deform (e.g., elastically deform) under external force. The first surface F1 of the wiring substrate 20 is the surface of the insulating substrate 21 located in the Z1 direction. The second surface F2 of the wiring substrate 20 is the surface of the insulating substrate 22 located in the Z2 direction.

[0016] The conductive layer 23 is a wiring pattern formed of a low-resistance conductive material. The conductive layer 23 is formed of a metal material such as copper (Cu), silver (Ag), or aluminum (Al), or an alloy material mainly composed of the above-mentioned metal materials. The conductive layer 23 may also be formed of other conductive materials such as SUS. Note that the material of the conductive layer 23 is not limited to the above examples and may be changed as desired. The relationship between the thickness of the conductive layer 23 and the thicknesses of the insulating substrate 21 and the insulating substrate 22 is arbitrary.

[0017] The conductive layer 23 has a plurality of connection terminals 25. Each connection terminal 25 is a terminal for electrically connecting the wiring board 20 to an external device. A current is supplied to the conductive layer 23 via each connection terminal 25. The wiring board 20 is used, for example, as a mounted component that uses the conductive layer 23 for transmitting an electrical signal, or as a heating device that uses the conductive layer 23 as a heating wire.

[0018] As illustrated in FIG. 3 , the conductive layer 23 is located between the insulating substrate 21 and the insulating substrate 22. Specifically, the insulating substrate 21 and the insulating substrate 22 are bonded to each other with the conductive layer 23 sandwiched therebetween by an adhesive 24. The adhesive 24 is, for example, an epoxy-based or acrylic-based resin material. However, the material of the adhesive 24 is not limited to the above examples and may be changed as desired. The insulating substrate 21 is located in the Z1 direction of the conductive layer 23, and the insulating substrate 22 is located in the Z2 direction of the conductive layer 23. The conductive layer 23 is a wiring pattern of a predetermined width formed in a predetermined shape across the entire area of ​​the insulating substrate 21 and the insulating substrate 22. As described above, the conductive layer 23 is formed on the insulating substrate 21 and the insulating substrate 22.

[0019] Openings 26 are formed in the insulating substrate 21 at locations corresponding to the connection terminals 25 of the conductive layer 23. Each connection terminal 25 is located inside the opening 26 in a plan view. That is, each connection terminal 25 of the conductive layer 23 is exposed from the insulating substrate 21 through the opening 26.

[0020] FIG. 4 is an enlarged plan view of a portion of the wiring board 20. FIG. 5 is a plan view in which the unevenness of the first surface F1 of the wiring board 20 is expressed by shading. In FIG. 4, peaks protruding toward the front side of the page are expressed by dashed lines, and recessed ends toward the back side of the page are expressed by chain lines. As illustrated in FIGS. 4 and 5, the wiring board 20 of the first embodiment has a structure (hereinafter referred to as a "folded structure 30") that is repeatedly bent in an in-plane direction. The folded structure 30 is a three-dimensional structure (i.e., an expandable structure) that enables the wiring board 20 to expand and contract in any direction parallel to the X-Y plane. In other words, the folded structure 30 allows the wiring board 20 to expand and contract in the X-axis and Y-axis directions. The folded structure 30 will be described in detail below.

[0021] 4, the folded structure 30 includes a plurality of fold lines W (W1, W2) that form a curved wave shape in a plan view. Specifically, each fold line W is a sine wave extending along the X-axis with the Y-axis direction as the wave height (amplitude) direction. The plurality of fold lines W are arranged at intervals from one another in the Y-axis direction.

[0022] Each of the plurality of fold lines W is a continuous curve corresponding to the ridge line La or the valley line Lb on the first face F1 and the second face F2. As illustrated in Figures 4 and 5, the plurality of fold lines W includes a first fold line W1 and a second fold line W2. The plurality of first fold lines W1 and the plurality of second fold lines W2 are alternately arranged along the Y axis.

[0023] Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 4 and Fig. 5, and Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 4 and Fig. 5. That is, Fig. 6 and Fig. 7 show a cross section perpendicular to the X-axis in wiring board 20. Note that Fig. 6 and Fig. 7 only show the outline of wiring board 20, and for convenience, the elements that make up wiring board 20 (insulating base material 21, insulating base material 22, conductive layer 23) are omitted from the illustration.

[0024] As illustrated in Figures 6 and 7, the first fold line W1 is a curve corresponding to the ridge line La of the first surface F1 and the valley line Lb of the second surface F2. The ridge line La of the first surface F1 is a curve connecting, along the X-axis, the peaks of the peaks that protrude in the Z1 direction on the first surface F1. The valley line Lb of the second surface F2 is a curve connecting, along the X-axis, the bottoms of the valleys that are recessed in the Z1 direction on the second surface F2. The ridge line La of the first surface F1 and the valley line Lb of the second surface F2 overlap each other in a plan view. In a plan view, the first fold line W1 is a wavy curve that includes the ridge line La of the first surface F1 and the valley line Lb of the second surface F2.

[0025] As illustrated in Figures 6 and 7, the second fold line W2 is a curve corresponding to the valley line Lb of the first surface F1 and the ridge line La of the second surface F2. The valley line Lb of the first surface F1 is a curve connecting, along the X-axis, valley portions recessed in the Z2 direction on the first surface F1. The ridge line La of the second surface F2 is a curve connecting, along the X-axis, peak portions protruding in the Z2 direction on the second surface F2. The valley line Lb of the first surface F1 and the ridge line La of the second surface F2 overlap each other in a plan view. In a plan view, the second fold line W2 is a wavy curve including the valley line Lb of the first surface F1 and the ridge line La of the second surface F2.

[0026] 6 and 7 , in a cross section perpendicular to the X-axis, the ridge line La and the valley line Lb adjacent to each other in the X-axis direction on the first surface F1 are connected by a connecting line C1. Similarly, the ridge line La and the valley line Lb adjacent to each other in the X-axis direction on the second surface F2 are connected by a connecting line C2. The connecting lines C1 and C2 in the first embodiment are straight lines inclined at a predetermined angle with respect to the Z-axis. That is, the wiring substrate 20 has a three-dimensional shape with a broken line shape in a cross section perpendicular to the X-axis.

[0027] 4 and 5, a region R (R1, R2) is a region between a pair of bending lines W adjacent to each other in the Y-axis direction. Each region R is an elongated region extending in the X-axis direction. A plurality of regions R are arranged in the Y-axis direction.

[0028] Fig. 8 is a cross-sectional view taken along line VIII-VIII in Figs. 4 and 5, and Fig. 9 is a cross-sectional view taken along line IX-IX in Figs. 4 and 5. As illustrated in Figs. 8 and 9, each region R between the first fold line W1 and the second fold line W2 has a wave shape in which convex portions Pa and concave portions Pb are alternately arranged along the X axis. The convex portions Pa are continuous curved surfaces that protrude in the Z1 direction. The concave portions Pb are continuous curved surfaces that are recessed in the Z2 direction. As explained above, the first surface F1 and the second surface F2 are continuous curved surfaces within each region R.

[0029] As illustrated in FIG. 4 , the multiple regions R include multiple first regions R1 and multiple second regions R2. The first region R1 is the region R between each first fold line W1 and the second fold line W2 adjacent to the first fold line W1 in the Y1 direction. On the other hand, the second region R2 is the region R between each first fold line W1 and the second fold line W2 adjacent to the first fold line W1 in the Y2 direction. Therefore, each of the multiple first regions R1 and each of the multiple second regions R2 are arranged alternately along the Y axis. FIG. 8 is a cross-sectional view of any one of the first regions R1, and FIG. 9 is a cross-sectional view of any one of the second regions R2.

[0030] As illustrated in FIG. 4 , the first fold line W1 has a wave shape including a plurality of first apexes Qa1 and a plurality of first bottoms Qb1 in a plan view. That is, in the first fold line W1, each of the plurality of first apexes Qa1 and each of the plurality of first bottoms Qb1 are alternately arranged along the X-axis. Similarly, the second fold line W2 has a wave shape including a plurality of second apexes Qa2 and a plurality of second bottoms Qb2 in a plan view. That is, in the second fold line W2, each of the plurality of second apexes Qa2 and each of the plurality of second bottoms Qb2 are alternately arranged along the X-axis. Furthermore, the first apexes Qa1 of each first fold line W1 and the second apexes Qa2 of each second fold line W2 are arranged in the Y-axis direction with a gap between them. Similarly, the first bottom portion Qb1 of each first fold line W1 and the second bottom portion Qb2 of each second fold line W2 are arranged in the Y-axis direction with a gap between them.

[0031] 4 and 8, in the first region R1, the portion between the first top portion Qa1 and the second top portion Qa2 is a convex portion Pa that protrudes in the Z1 direction, and the portion between the first bottom portion Qb1 and the second bottom portion Qb2 is a concave portion Pb that is recessed in the Z2 direction. That is, in the first region R1, as described above, the convex portions Pa and the concave portions Pb are alternately arranged along the X axis.

[0032] 4 and 9, in the second region R2, the area between the first top portion Qa1 and the second top portion Qa2 is a recess Pb recessed in the Z2 direction, and the area between the first bottom portion Qb1 and the second bottom portion Qb2 is a protrusion Pa protruding in the Z1 direction. That is, in the second region R2, as described above, the protrusions Pa and the recesses Pb are alternately arranged along the X axis.

[0033] The bending structure 30 of the wiring board 20 is as described above. Note that in the above description, attention has been focused on the shapes of the first surface F1 of the insulating substrate 21 and the second surface F2 of the insulating substrate 22, but the conductive layer 23 between the insulating substrates 21 and 22 also has a three-dimensional shape corresponding to the bending structure 30. Specifically, the conductive layer 23 has a plurality of bending lines W that extend along the X-axis in a curved wave shape in a plan view.

[0034] As described above, in the first embodiment, the plurality of bending lines W corresponding to the ridge lines La or valley lines Lb of the first face F1 and the second face F2 are arranged along the Y axis, so that the wiring board 20 can be expanded and contracted (extended or contracted) in both the X-axis and Y-axis directions by, for example, an external force. Therefore, the wiring board 20 can be flexibly adapted to various three-dimensional shapes of the object 10.

[0035] Specifically, the wiring board 20 can contract in the direction of the Y axis so that the first fold lines W1 and the second fold lines W2 approach each other in a plan view. The wiring board 20 can also extend in the direction of the Y axis so that the first fold lines W1 and the second fold lines W2 move away from each other in a plan view. That is, by extending the multiple fold lines W in the direction of the Y axis, the wiring board 20 becomes flat. Specifically, the wiring board 20 is extended into a flat shape so that the angle between each connecting line C1 and each connecting line C2 is 180°.

[0036] When an external force is applied to the wiring board 20 and the wiring board 20 is stretched in the Y-axis (second axis) direction, and then the external force is removed, the wiring board 20 contracts in the Y-axis direction toward its pre-stretched shape due to an elastic restoring force. On the other hand, when an external force is applied to the wiring board 20 and the wiring board 20 is stretched in the Y-axis direction toward its pre-stretched shape due to an elastic restoring force, the wiring board 20 contracts in the Y-axis direction toward its pre-stretched shape due to an external force.

[0037] The wiring substrate 20 can be contracted in the direction of the X-axis so that the convex portions Pa and the concave portions Pb approach each other in a plan view. The wiring substrate 20 can be extended in the direction of the X-axis so that the convex portions Pa and the concave portions Pb move away from each other in a plan view. That is, by extending the multiple bending lines W in the direction of the X-axis, the wiring substrate 20 becomes flat. Specifically, the wiring substrate 20 is extended in a flat shape so that the convex portions Pa and the concave portions Pb are located on a straight line along the X-axis.

[0038] When an external force is applied to the wiring board 20 and the wiring board 20 is stretched in the direction of the X-axis (first axis), and then the external force is removed, the wiring board 20 contracts in the direction of the X-axis due to an elastic restoring force toward its original shape before the stretching. On the other hand, when an external force is applied to the wiring board 20 and the wiring board 20 is stretched in the direction of the X-axis due to an elastic restoring force toward its original shape before the contraction.

[0039] Furthermore, the plurality of bending lines W corresponding to the ridge lines La and valley lines Lb of the first surface F1 and the second surface F2 are curved and wavy (e.g., sinusoidal) in plan view. Therefore, compared to a configuration in which the plurality of bending lines W are formed by straight lines (e.g., broken lines) in plan view, local stress in the conductive layer 23 is reduced. Therefore, damage (e.g., breakage or buckling) of the conductive layer 23 due to local stress can be suppressed.

[0040] Specifically, even if the wiring substrate 20 is repeatedly expanded and contracted, the conductive layer 23 will not be damaged (e.g., broken or buckled). That is, even if the bending angle at each of the plurality of bending lines W is changed, the conductive layer 23 will not be damaged. The bending angle at each bending line W is, for example, the angle between the connecting line C1 and the connecting line C2.

[0041] In the above description, a configuration in which the characteristics of a plurality of bend lines W (hereinafter referred to as "bend line characteristics") are the same has been exemplified, but as shown in the examples of Figures 10 to 13, the bend line characteristics may differ for each bend line W. The bend line characteristics can also be expressed as conditions related to the shape or arrangement of each bend line W.

[0042] As illustrated in Fig. 10, the amplitude A may be different for each of the plurality of bending lines W. Fig. 10 illustrates an example in which the amplitude A of the bending lines W increases as the bending lines W are closer to the Y2 direction.

[0043] As illustrated in Fig. 11, the arrangement pitch P may be different for each of the plurality of bending lines W. The arrangement pitch P is the distance between the amplitude centers of the bending lines W. Fig. 11 illustrates an example in which the arrangement pitch P is larger for bending lines W located in the Y2 direction among the plurality of bending lines W.

[0044] As illustrated in Fig. 12, the interval D may be different for each of the plurality of bend lines W. Fig. 11 illustrates an example in which the interval D is larger for the bend lines W that are closer to the Y2 direction.

[0045] As illustrated in Fig. 13, the wavelength λ may be different for each of the plurality of bending lines W. Fig. 13 illustrates an example in which the bending lines W located in the Y2 direction among the plurality of bending lines W have a larger wavelength λ. In the configuration of Fig. 13, the wave number is common across the plurality of bending lines W. Therefore, the total length of each bending line W differs for each bending line W. Specifically, the bending lines W located in the Y2 direction among the plurality of bending lines W have a longer total length.

[0046] 10 to 13 may be combined. That is, for example, two or more bent curve characteristics selected from the plurality of bent curve characteristics (amplitude A, arrangement pitch P, interval D, and wavelength λ) exemplified above may be different for each bent curve W.

[0047] 10 to 13 illustrate an example in which the bend curve characteristics (amplitude A, arrangement pitch P, interval D, and wavelength λ) of the bend curve W monotonically increase in one direction along the Y axis, but the manner in which the bend curve characteristics change is not limited to the above example. For example, a configuration in which the bend curve characteristics increase or decrease toward a specific position in the Y axis direction on the wiring substrate 20, or a configuration in which the bend curve characteristics are maintained constant within a specific range in the Y axis direction, is also possible.

[0048] B: Second Embodiment A second embodiment will be described. Note that, for elements in the following exemplary aspects that have the same functions as those in the first embodiment, the same reference numerals as those in the first embodiment will be used, and detailed descriptions of each element will be omitted as appropriate.

[0049] 14 is an enlarged plan view of a portion of the wiring board 20 according to the second embodiment. As illustrated in FIG. 14 , a plurality of through holes H are formed in the wiring board 20 according to the second embodiment. The through holes H are circular openings that penetrate the insulating base material 21 and the insulating base material 22. The conductive layer 23 is formed so as not to overlap the through holes H in a planar view. The planar shape of the through holes H is not limited to a circular shape. For example, polygonal through holes H may be formed in the wiring board 20.

[0050] Each of the plurality of through holes H is formed in a portion corresponding to the apex Qa (Qa1, Qa2) on each bending line W. Specifically, a substantially circular through hole H is formed in a portion adjacent in the Y2 direction to the apex Qa on each bending line W. As described above, in the second embodiment, the through holes H are formed in the wiring substrate 20 (insulating base material 21 and insulating base material 22) on each of the plurality of bending lines W on the wiring substrate 20 (insulating base material 21 and insulating base material 22) on the portions corresponding to the apex Qa.

[0051] The second embodiment also achieves the same effects as the first embodiment. Furthermore, in the second embodiment, through holes H are formed in the insulating base material 21 and the insulating base material 22 at positions corresponding to the apexes Qa (Qa1, Qa2) at each bending line W. Therefore, compared to a configuration in which the through holes H are not formed (for example, the first embodiment), the flexibility of the wiring board 20 can be improved. That is, in the second embodiment, the wiring board 20 can be easily deformed to follow the three-dimensional shape of the object 10.

[0052] Fig. 15 is an explanatory diagram relating to a test for evaluating the flexibility of wiring board 20. As illustrated in Fig. 15, with end E1 of wiring board 20 held by holder 41, load 42 was applied to end E2 on the opposite side, and the amount of deflection δ of end E2 was measured as an evaluation value for the flexibility of wiring board 20. Test 1 in Fig. 15 is a test in which one end of wiring board 20 located in the Y-axis direction is held as end E1, and Test 2 is a test in which one end of wiring board 20 located in the X-axis direction is held as end E1.

[0053] Fig. 16 shows the results of evaluating the flexibility of wiring substrate 20. The reference sample in Fig. 16 is a configuration in which no through-hole H is formed (for example, the first embodiment). Fig. 16 shows relative measurement values ​​in parentheses, with the deflection amount δ of the reference sample set as a reference value (=1).

[0054] Test sample 1 in Fig. 16 has a configuration in which a through hole H is formed at the midpoint of each fold line W, as illustrated in Fig. 17. Specifically, the through hole H is formed near the midpoint between an apex Qa and a bottom Qb that are adjacent in the Y-axis direction. Test sample 2 in Fig. 16 has a configuration in which a through hole H is formed at the inflection point of each fold line W, as illustrated in Fig. 18.

[0055] As can be seen from FIG. 16 , according to the second embodiment in which through holes H are formed in the wiring substrate 20, the amount of deflection δ can be increased compared to a reference sample in which through holes H are not formed. Furthermore, according to the second embodiment in which through holes H are formed at the apexes Qa (Qa1, Qa2) of each bending line W, the amount of deflection δ can be increased even compared to test sample 1 in which through holes H are formed in the middle of each bending line W and test sample 2 in which through holes H are formed at the inflection points of each bending line W. As described above, according to the second embodiment, the flexibility of the wiring substrate 20 can be effectively improved. Note that test samples 1 and 2 are also included within the scope of the present disclosure.

[0056] In the second embodiment, through holes H are formed in the apexes Qa (Qa1, Qa2) of each fold line W, but as illustrated in Fig. 19, through holes H may be formed in portions of each fold line W corresponding to the bottoms Qb (Qb1, Qb2). Also, as illustrated in Fig. 20, through holes H may be formed in portions of each fold line W corresponding to the apexes Qa (Qa1, Qa2) and the bottoms Qb (Qb1, Qb2). Also, a configuration in which through holes H are formed only in some of the apexes Qa of each fold line W, or a configuration in which through holes H are formed only in some of the bottoms Qb of each fold line W may be employed.

[0057] C: Third Embodiment The third embodiment is a method for manufacturing the above-described device 100. Fig. 21 is a flowchart illustrating a specific procedure for manufacturing the device 100. As illustrated in Fig. 21, the process for manufacturing the device 100 includes a first step S1 and a second step S2.

[0058] In the first step S1, the wiring board 20 according to the first embodiment is prepared. That is, the wiring board 20 prepared in the first step S1 has a folded structure 30 in which a plurality of folding lines W extending along the X axis and arranged along the Y axis are curved and wave-shaped in a plan view. Specifically, the first step S1 is a step of manufacturing the wiring board 20.

[0059] After the first step S1, the second step S2 is performed. In the second step S2, the wiring substrate 20 is deformed to conform to the three-dimensional shape of the object 10, so that the object 10 is covered with the wiring substrate 20.

[0060] As described above, in the third embodiment, the plurality of bending lines W corresponding to the ridge lines La or valley lines Lb of the first surface F1 and the second surface F2 are arranged along the Y axis, and therefore the wiring board 20 can expand and contract in both the X-axis and Y-axis directions. Therefore, by flexibly deforming the wiring board 20 so as to follow the three-dimensional shape of the object 10, objects 10 of various three-dimensional shapes can be easily covered with the wiring board 20.

[0061] Furthermore, the plurality of bending lines W corresponding to the ridge lines La and valley lines Lb of the first surface F1 and the second surface F2 are curved and wavy (e.g., sinusoidal) in plan view. Therefore, compared to a configuration in which the plurality of bending lines W are formed by straight lines (e.g., broken lines) in plan view, local stress in the conductive layer 23 is reduced. Therefore, in the second step S2 of deforming the wiring substrate 20, damage (e.g., breakage or buckling) of the conductive layer 23 due to local stress can be suppressed.

[0062] 21 , the first step S1 includes a preparation step S11 and a molding step S12. In the preparation step S11, a flat wiring board (hereinafter referred to as "initial substrate 28") including an insulating substrate 21, an insulating substrate 22, and a conductive layer 23 is prepared. That is, the initial substrate 28 is an initial wiring board 20 without a bent structure 30 formed thereon. That is, the first surface F1 and the second surface F2 of the initial substrate 28 are flat surfaces without any irregularities. In addition to the step of manufacturing the initial substrate 28, the preparation step S11 may also include the step of purchasing the initial substrate 28.

[0063] After the preparation step S11, the molding step S12 is carried out. In the molding step S12, the initial substrate 28 prepared in the preparation step S11 is pressed to form the folded structure 30. That is, the molding step S12 is a step of manufacturing the wiring board 20 having the folded structure 30.

[0064] FIG. 22 is an explanatory diagram of the molding step S12 in the third embodiment. The press working in the molding step S12 is compression molding using a molding apparatus 50 shown in FIG. 22. As shown in FIG. 22, the molding apparatus 50 is composed of a first compression die 51 and a second compression die 52. The first compression die 51 is a die having a first molding surface 511. The first molding surface 511 is a surface that faces and contacts the first surface F1 of the initial substrate 28. The second compression die 52 is a die having a second molding surface 521. The second molding surface 521 is a surface that faces and contacts the second surface F2 of the initial substrate 28. The first molding surface 511 and the second molding surface 521 face each other. Note that the first compression die 51 and the second compression die 52 are not limited to metal molding dies (dies). For example, a resin mold formed by a 3D printer may be used as the molding molds (first compression mold 51 and second compression mold 52) in the molding step S12.

[0065] A first molding structure 512 corresponding to the bent structure 30 is formed on the first molding surface 511. The first molding structure 512 is a concave-convex structure corresponding to the bent structure 30 to be formed on the first surface F1 of the wiring substrate 20. Recesses 513 are formed on the first molding surface 511 at positions facing each connection terminal 25 of the wiring substrate 20. The recesses 513 of the first molding surface 511 are depressions for preventing the first molding surface 511 from coming into contact with each connection terminal 25.

[0066] Similarly, second molding surface 521 is formed with second molding structure 522 corresponding to bent structure 30. Second molding structure 522 is a concave-convex structure corresponding to bent structure 30 to be formed on second surface F2 of wiring substrate 20. Note that recesses 513 corresponding to each connection terminal 25 may also be formed on second molding surface 521.

[0067] In the press working of the molding step S12, the initial substrate 28 is placed between the first compression die 51 and the second compression die 52 described above. Specifically, the initial substrate 28 is placed so that the first surface F1 of the initial substrate 28 faces the first molding surface 511 of the first compression die 51 and the second surface F2 of the initial substrate 28 faces the second molding surface 521 of the second compression die 52. The connection terminals 25 of the conductive layer 23 on the initial substrate 28 are located inside the recesses 513 of the first molding surface 511. In other words, the connection terminals 25 do not contact the first molding surface 511.

[0068] The initial substrate 28 arranged in the above-described state is compressed by the first compression die 51 and the second compression die 52. For example, one of the first compression die 51 and the second compression die 52 is pressed against the other. By compressing the initial substrate 28 as described above, the wiring substrate 20 including the bent structure 30 described in the first embodiment is manufactured. Note that the initial substrate 28 may be heated in the molding step S12.

[0069] As described above, according to the third embodiment, the wiring board 20 having the bent structure 30 formed thereon can be manufactured by the simple process of pressing the initial base material 28. In particular, in the third embodiment, the wiring board 20 having the bent structure 30 formed thereon can be manufactured by the simple process of compressing the initial base material 28 using the first compression die 51 and the second compression die 52.

[0070] In the third embodiment, a recess 513 is formed on the first molding surface 511 of the first compression mold 51. In the molding step S12, the connection terminal 25 is positioned inside the recess 513, so that the bent structure 30 is not formed on the connection terminal 25. Therefore, the bent structure 30 can be formed on the wiring substrate 20 while the surface of the connection terminal 25 is maintained flat. As a result of the connection terminal 25 being maintained flat, electrical connection between an external device and the connection terminal 25 is facilitated.

[0071] D: Fourth Embodiment The fourth embodiment is a method for manufacturing the device 100, similar to the third embodiment. In the fourth embodiment, the procedure of the molding step S12 in the first step S1 differs from that of the third embodiment. The procedures other than the molding step S12 are the same as those of the third embodiment.

[0072] Fig. 23 is an explanatory diagram of the molding step S12 in the fourth embodiment. The press working in the molding step S12 in the fourth embodiment is compression molding (roll press) using a molding device 60 shown in Fig. 23. The molding device 60 includes a first pressure roller 61 and a second pressure roller 62.

[0073] The first pressure roller 61 is a cylindrical rotating body whose outer peripheral surface constitutes a first shaping surface 611. The first shaping surface 611 is an outer peripheral surface that faces and contacts the first surface F1 of the initial substrate 28. The second pressure roller 62 is a cylindrical rotating body whose outer peripheral surface constitutes a second shaping surface 621. The second shaping surface 621 is an outer peripheral surface that faces and contacts the second surface F2 of the initial substrate 28. The first pressure roller 61 and the second pressure roller 62 are installed so that the rotation axes of the first pressure roller 61 and the second pressure roller 62 are parallel to each other with a gap between them.

[0074] A first molding structure 612 corresponding to the bent structure 30 is formed on the first molding surface 611. The first molding structure 612 is a concave-convex structure corresponding to the bent structure 30 to be formed on the first surface F1 of the wiring substrate 20. Recesses 613 are formed on the first molding surface 611 at positions facing each connection terminal 25 of the wiring substrate 20.

[0075] Similarly, a second molding structure 622 corresponding to the bent structure 30 is formed on the second molding surface 621. The second molding structure 622 is a concave-convex structure corresponding to the bent structure 30 to be formed on the second surface F2 of the wiring substrate 20. Note that the recesses 613 corresponding to each connection terminal 25 may also be formed on the second molding surface 621.

[0076] In the press working of the molding step S12, the initial substrate 28 is placed between the first pressure roller 61 and the second pressure roller 62 described above. Specifically, the initial substrate 28 is placed so that the first surface F1 of the initial substrate 28 faces the first molding surface 611 of the first pressure roller 61 and so that the second surface F2 of the initial substrate 28 faces the second molding surface 621 of the second pressure roller 62. The connection terminals 25 of the conductive layer 23 in the initial substrate 28 are located inside the recesses 613 of the first molding surface 611.

[0077] With the initial substrate 28 in place, the first pressure roller 61 and the second pressure roller 62 are rotated. The first pressure roller 61 and the second pressure roller 62 are rotated in opposite directions. Therefore, the initial substrate 28 is conveyed while being compressed by the first pressure roller 61 and the second pressure roller 62. By compressing the initial substrate 28 as described above, the wiring substrate 20 including the folded structure 30 described in the first embodiment is manufactured. Note that the initial substrate 28 may be heated in the molding step S12.

[0078] The fourth embodiment also achieves the same effects as the third embodiment. Moreover, in the fourth embodiment, the wiring substrate 20 having the folded structure 30 formed thereon can be manufactured by a simple process of compressing the initial base material 28 with the first pressure roller 61 and the second pressure roller 62.

[0079] In the third and fourth embodiments, the wiring board 20 of the first embodiment is assumed to be manufactured, but the wiring board 20 of the second embodiment is also manufactured using the same procedure. In the second embodiment, each through hole H may be formed in the initial base material 28 before the molding step S12 is performed, or may be formed in the wiring board 20 after the molding step S12 is performed. In other words, the step of forming the multiple through holes H may be performed either before or after the molding step S12 is performed.

[0080] 24 is a cross-sectional view of a wiring board 20 according to a fifth embodiment. As with the above-described embodiments, the wiring board 20 according to the fifth embodiment is a laminate including an insulating substrate 21, an insulating substrate 22, and a conductive layer 23. Specifically, as in the first embodiment, the conductive layer 23 is interposed between the insulating substrate 21 and the insulating substrate 22.

[0081] The wiring board 20 of the fifth embodiment is used as a heating device that utilizes the conductive layer 23 as a heating wire. That is, the conductive layer 23 generates heat when a current is supplied to the conductive layer 23. Note that although the conductive layer 23 is illustrated in FIG. 24 as a single layer that is continuous over a wide area, the actual conductive layer 23 is composed of a wiring pattern of a predetermined width.

[0082] As described in the first embodiment, the conductive layer 23 has a three-dimensional shape corresponding to the bent structure 30. As illustrated in Fig. 24, the conductive layer 23 has a wave shape in a cross-sectional view. Specifically, as described above with reference to Figs. 6 and 7, the conductive layer 23 has a wave shape composed of straight lines inclined at a predetermined angle with respect to the Z axis in a cross-section perpendicular to the X axis. Furthermore, as described above with reference to Figs. 8 and 9, the conductive layer 23 has a wave shape composed of continuous curves in a cross-section perpendicular to the Y axis.

[0083] As described above, the conductive layer 23 of the wiring board 20 is formed in a wave-like shape in cross section. Therefore, it is possible to increase the conductor density per unit projected area compared to a configuration in which the conductive layer 23 is formed in a simple flat shape. Therefore, when the wiring board 20 is used in a heating device that uses the conductive layer 23 as a heating wire, it has the advantage of easily ensuring the amount of heat generated. Note that the unit projected area means, for example, the unit area when the conductive layer 23 is projected onto an imaginary plane perpendicular to the Z axis.

[0084] In the fifth embodiment, the insulating substrate 21 is formed of a heat-insulating insulating material. On the other hand, the insulating substrate 22 is formed of a thermally conductive insulating material. That is, the insulating substrate 22 has higher thermal conductivity than the insulating substrate 21. Therefore, the component of the heat generated from the conductive layer 23 that moves toward the insulating substrate 21 is insulated by the insulating substrate 21. On the other hand, the component of the heat generated from the conductive layer 23 that moves toward the insulating substrate 22 propagates to the insulating substrate 22. Therefore, the heat propagated to the insulating substrate 22 is radiated to the external space in the Z2 direction, as shown by the arrow in FIG. 24 . As described above, the wiring substrate 20 of the fifth embodiment is used as a heating device that efficiently radiates heat only in one direction (the Z2 direction) along the Z axis.

[0085] F: Sixth Embodiment Figure 25 shows an application example of the wiring board 20 according to the sixth embodiment. In the sixth embodiment, the wiring board 20 according to any of the above-described embodiments is applied to a joint mechanism 71 of various mechanical systems. The joint mechanism 71 is a mechanism that is applied to, for example, the working arm of an industrial robot, and includes a first member 711, a second member 712, and a joint portion 713. The first member 711 and the second member 712 are connected via the joint portion 713. The joint portion 713 includes a rotation mechanism such as a motor that rotates one of the first portion 711 and the second portion 712 relative to the other.

[0086] The wiring board 20 according to the present disclosure is installed across a first member 711 and a second member 712. Specifically, portions of the wiring board 20 spaced apart in the Y-axis direction are fixed to the first member 711 and the second member 712 by, for example, a bonding material 714. In conjunction with the relative rotation between the first member 711 and the second member 712, the wiring board 20 expands or contracts in the Y-axis direction.

[0087] G: Seventh Embodiment FIG. 26 illustrates an application example of the wiring board 20 according to the seventh embodiment. In the seventh embodiment, the wiring board 20 according to each of the above-described embodiments is applied to a rotation mechanism 72 of various mechanical systems. The rotation mechanism 72 is a mechanism that is applied to, for example, an industrial robot, and includes a first member 721, a second member 722, and a shaft member 723. The shaft member 723 is a cylindrical structure. The first member 721 and the second member 722 are annular members into which the shaft member 723 is inserted. The first member 721 is fixed to the shaft member 723, and the second member 722 is rotatable relative to the shaft member 723. Therefore, for example, one of the first member 721 and the second member 722 rotates relative to the other in conjunction with the rotation of the shaft member 723.

[0088] The wiring board 20 according to the present disclosure is installed across a first member 721 and a second member 722. Specifically, portions of the wiring board 20 spaced apart in the Y-axis direction are fixed to the first member 721 and the second member 722, for example, by a bonding material 724. In conjunction with the relative rotation between the first member 721 and the second member 722, the wiring board 20 expands or contracts in the Y-axis direction while twisting.

[0089] H: Eighth Embodiment FIG. 27 illustrates an application example of the wiring board 20 according to the eighth embodiment. In the eighth embodiment, the wiring board 20 according to each of the above-described embodiments is applied to a wiring structure 73 of various mechanical systems. The wiring structure 73 is a mechanism applied to, for example, an industrial robot, and includes a first member 731, a second member 732, and a wiring 733. The wiring 733 is a transmission path that electrically connects devices and transmits power or signals. The wiring 733 is, for example, a twisted wiring including multiple wires. The first member 731 and the second member 732 are annular members into which the wiring 733 is inserted. The first member 731 is fixed to the wiring 733, and the second member 732 is rotatable relative to the wiring 733. Therefore, the second member 732 rotates relative to the wiring 733 and the first member 731.

[0090] The wiring board 20 according to the present disclosure is installed across a first member 731 and a second member 732. Specifically, portions of the wiring board 20 that are spaced apart in the Y-axis direction are fixed to the first member 731 and the second member 732. In conjunction with the relative rotation between the first member 731 and the second member 732, the wiring board 20 expands or contracts in the Y-axis direction while twisting. The wiring board 20 also curves to follow the curvature of the wiring 733.

[0091] I: Modifications Specific modifications that can be added to the above-mentioned embodiments are exemplified below. Two or more embodiments arbitrarily selected from the following examples may be combined as appropriate within the scope of not mutually contradicting each other.

[0092] (1) In the above-described embodiments, as shown in Figures 6 and 7, the wiring board 20 has a folded line shape in a cross section perpendicular to the X axis. That is, the connecting line C1 of the first surface F1 and the connecting line C2 of the second surface F2 are straight lines. However, as shown in Figure 28, the wiring board 20 may have a curved shape in a cross section perpendicular to the X axis. Specifically, the connecting line C1 and the connecting line C2 connecting the ridge line La and the valley line Lb may be curved lines.

[0093] For example, in a cross section perpendicular to the X axis, a ridge line La and a valley line Lb adjacent to each other on the first face F1 are connected by a continuous wave-shaped curve across a plurality of bend lines W (W1, W2). Similarly, in a cross section perpendicular to the X axis, a ridge line La and a valley line Lb adjacent to each other on the second face F2 are connected by a continuous wave-shaped curve across a plurality of bend lines W (W1, W2). In other words, in a cross section perpendicular to the X axis, the first face F1 and the second face F2 are continuous wave-shaped curves across a plurality of bend lines W.

[0094] As shown in the above examples, the ridge line La is not limited to a line where two planes or curved surfaces intersect discontinuously, but may be a straight line or curve connecting the peaks (maximum points) of the peaks on the curved surface. Similarly, the valley line Lb is not limited to a line where two planes or curved surfaces intersect discontinuously, but may be a straight line or curve connecting the bottoms (minimum points) of the valleys on the curved surface. Accordingly, the bend line W is similarly not limited to a line where two planes or curved surfaces intersect discontinuously, but may be a straight line or curve connecting the peaks or bottoms on the curved surface.

[0095] (2) In the above-described embodiments, the bend curve characteristics (amplitude A, arrangement pitch P, interval D, and wavelength λ) are constant over the entire length of a single bend curve W. However, the bend curve characteristics may vary depending on the position between both ends of the bend curve W. For example, FIG. 29 illustrates a configuration in which the amplitude A is larger at a position closer to the end of a single bend curve W in the X1 direction. While FIG. 29 focuses on the amplitude A of the bend curve W, other bend curve characteristics such as interval D or wavelength λ may vary depending on the position on a single bend curve W.

[0096] (3) In the above-described embodiments, the plurality of fold lines W are parallel to one another, but the relationship between the plurality of fold lines W is not limited to the above examples. For example, as illustrated in Fig. 30 , a configuration in which the plurality of fold lines W extend radially from a specific point O on the wiring board 20 is also possible. The planar shape of the wiring board 20 in Fig. 30 is fan-shaped. As can be understood from the example in Fig. 30 , the plurality of fold lines W may be arranged side by side, inclined at a predetermined angle to one another.

[0097] (4) In each of the above-described embodiments, the first fold line W1 and the second fold line W2 are spaced apart by a distance D in the Y-axis direction. However, the positional relationship between the first fold line W1 and the second fold line W2 in the Y-axis direction (e.g., the presence or absence of the distance D) is not limited to the above examples.

[0098] For example, as illustrated in Figure 31, the range α1 of the first fold line W1 in the direction of the Y axis and the range α2 of the second fold line W2 in the direction of the Y axis may partially overlap in the direction of the Y axis. The configuration in Figure 31 can also be expressed as a configuration in which a portion of the second fold line W2 is included within the range α1 corresponding to the amplitude A of the first fold line W1, or a configuration in which a portion of the first fold line W1 is included within the range α2 corresponding to the amplitude A of the second fold line W2. As can be understood from the above explanation, the first fold line W1 and the second fold line W2 do not need to be spaced apart from each other in the direction of the Y axis. In other words, the distance D between the first fold line W1 and the second fold line W2 may be omitted.

[0099] (5) In each of the above-described embodiments, the X-axis along which each bend line W runs is linear. However, the X-axis may be a bent line formed by connecting multiple straight lines at different angles, or a curved line such as an arc.

[0100] (6) In the above-described embodiments, the bending lines W extend along the linear X-axis, but the bending lines W (W1, W2) may form a closed figure in a plan view. That is, the bending lines W may be formed in a loop shape along the closed figure.

[0101] For example, Fig. 32 is a plan view of a wiring board 20 according to a modified example. In Fig. 32, as in Fig. 4, peaks protruding toward the front side of the paper (Z1 direction) are represented by dashed lines, and ends recessed toward the back side of the paper (Z2 direction) are represented by chain lines. Also, as illustrated in Fig. 4, in the following description, the direction of the circumference of a virtual circle of any diameter centered at a specific point O will be referred to as the "circumferential direction," and the direction of the radius of the virtual circle will be referred to as the "radial direction." As in the above-described embodiments, the wiring board 20 of Fig. 32 includes an insulating substrate 21, an insulating substrate 22, and a conductive layer 23 interposed therebetween.

[0102] In the wiring board 20 illustrated in FIG. 32 , the planar shape of each bend line W is an endless closed figure defined in a loop shape in plan view. Specifically, the planar shape of each bend line W is a closed figure obtained by annulating a curved wave shape into a circular shape in plan view. That is, each bend line W is a sine wave that forms a closed figure by extending along the circumferential direction of a virtual circle, with the radial direction of the circle being the direction of wave height (amplitude). Multiple bend lines W with different diameters are arranged concentrically around point O.

[0103] The multiple fold lines W include multiple first fold lines W1 and multiple second fold lines W2. Each first fold line W1 and each second fold line W2 are adjacent to one another in the radial direction. That is, the first fold lines W1 and the second fold lines W2 are arranged alternately in the radial direction. For example, one second fold line W2 is located in a circular region between two first fold lines W1 having different diameters. Also, one first fold line W1 is located in a circular region between two second fold lines W2 having different diameters. The circular region between two radially adjacent fold lines W (W1, W2) is a curved surface whose peaks and bottoms are arranged alternately along the circumferential direction.

[0104] Figure 33 is a cross-sectional view taken along line XXX-XXX in Figure 32. As illustrated in Figures 32 and 33, each of the multiple bending lines W is a continuous curve corresponding to the ridge lines La or valley lines Lb on the first face F1 and the second face F2. On each of the first face F1 and the second face F2, the ridge lines La and valley lines Lb are arranged concentrically and in a loop shape (i.e., a closed figure), and the ridge lines La and valley lines Lb are arranged alternately in the radial direction. As illustrated above, the ridge lines La and valley lines Lb in this modified example form a closed figure in a plan view.

[0105] The first fold line W1 is a curve corresponding to the ridge line La of the first face F1 and the valley line Lb of the second face F2. The ridge line La of the first face F1 is a curve connecting the tops of the peaks that protrude in the Z1 direction on the first face F1. The valley line Lb of the second face F2 is a curve connecting the bottoms of the valleys that are recessed in the Z1 direction on the second face F2.

[0106] Similarly, the second fold line W2 is a curve corresponding to the valley line Lb of the first surface F1 and the ridge line La of the second surface F2. The valley line Lb of the first surface F1 is a curve connecting the bottoms of the valleys recessed in the Z2 direction on the first surface F1. The ridge line La of the second surface F2 is a curve connecting the tops of the peaks protruding in the Z2 direction on the second surface F2.

[0107] 32, multiple bending lines W corresponding to the ridge lines La or valley lines Lb of the first face F1 and the second face F2 are arranged in the radial direction, so that the wiring board 20 can expand and contract in both the radial direction and the circumferential direction. Therefore, the wiring board 20 can flexibly conform to various three-dimensional shapes of the object 10.

[0108] In the above description, an example in which each fold line W is circular has been described, but the planar shape of each fold line W (or the shape of a closed figure along which each fold line W extends) is not limited to the above example. For example, each fold line W may be a polygonal shape such as a triangle (e.g., an equilateral triangle) or a quadrangle (e.g., a square). The wiring substrate 20 illustrated in FIG. 32 is manufactured by the method exemplified in the third or fourth embodiment. However, the method for manufacturing the wiring substrate 20 according to the present disclosure is not limited to the above example.

[0109] (7) In the above-described embodiments, the wiring board 20 covers the entire upper surface of the object 10, but the relationship between the object 10 and the wiring board 20 is not limited to the above examples. For example, as illustrated in Fig. 34, a configuration in which the wiring board 20 covers only a portion of the upper surface of the object 10 is also possible.

[0110] (8) As illustrated in FIG. 35 , the wiring board 20 may include a covering material 27. The covering material 27 is a film that covers a laminate of the insulating substrate 21, the insulating substrate 22, and the conductive layer 23. Specifically, the covering material 27 covers the first surface F1 of the insulating substrate 21, the second surface F2 of the insulating substrate 22, and the side surfaces of the laminate. Similar to the insulating substrate 21, openings 26 are formed in the covering material 27 at locations corresponding to each connection terminal 25. The covering material 27 has a uniform thickness throughout. However, the thickness may vary depending on the region of the covering material 27.

[0111] The covering material 27 is an elastic body formed from an elastic material. For example, the covering material 27 is formed from an elastic material such as synthetic rubber or foamed resin. Examples of synthetic rubber used to form the covering material 27 include urethane rubber and silicone rubber. Examples of foamed resin used to form the covering material 27 include urethane foam and styrene foam. However, the material of the covering material 27 is not limited to the above examples and may be changed as desired. Specifically, the covering material 27 may be formed from a material other than an elastic material. For example, assuming a situation in which the wiring board 20 is used in a static state (i.e., a state in which the wiring board 20 does not substantially deform) as illustrated in FIG. 1, elastic deformation of the wiring board 20 after mounting on the target object 10 may not be necessary. Therefore, the covering material 27 may be formed from a resin material such as a thermoplastic resin or a thermosetting resin. Alternatively, the covering material 27 may be formed from a laminate of multiple layers formed from different materials.

[0112] The method for forming the covering material 27 is arbitrary. For example, the covering material 27 is formed separately from the laminate of the insulating base material 21, the insulating base material 22, and the conductive layer 23, and is bonded to the surfaces (first surface F1, second surface F2, and side surfaces) of the laminate using, for example, an adhesive. The covering material 27 may also be formed by molding using a mold. The formation of the covering material 27 can also be expressed as combining the wiring board 20. The covering material 27 may also be formed by spraying a liquid elastic material onto the first surface F1 and the second surface F2 and curing it. The covering material 27 may be provided in any of the above-described exemplary forms.

[0113] As illustrated in Fig. 36, a three-dimensional shape of protrusions and recesses that reflects the protrusions and recesses of the first surface F1 and the second surface F2 may be formed on the surface of the covering material 27. Furthermore, as illustrated in Fig. 37, the surface of the covering material 27 may be a flat surface that does not reflect the protrusions and recesses of the first surface F1 and the second surface F2. In other words, the covering material 27 may be formed so as to fill in the protrusions and recesses of the first surface F1 and the second surface F2.

[0114] 35 illustrates the coating material 27 covering the entire first surface F1 of the insulating substrate 21, the second surface F2 of the insulating substrate 22, and the side surface of the laminate, but it is also possible to have a configuration in which the coating material 27 is not formed on one of the first surface F1 and the second surface F2, or to have the coating material 27 not formed on the side surface of the laminate.It is also possible to have the coating material 27 formed only on a partial region of the first surface F1, or to have the coating material 27 formed only on a partial region of the second surface F2.

[0115] In the above description, covering material 27 has been illustrated as an element constituting wiring board 20, but covering material 27 may also be interpreted as an element separate from wiring board 20. That is, the configuration in Fig. 35 can also be expressed as a mounted component in which covering material 27 is formed on wiring board 20 including insulating base material 21, insulating base material 22, and conductive layer 23. Furthermore, the surface of covering material 27 facing the Z1 direction may be defined as first face F1, and the surface of covering material 27 facing the Z2 direction may be defined as second face F2.

[0116] Fig. 38 is a graph showing the elastic characteristics of wiring board 20. Specifically, Fig. 38 shows the relationship between the amount of extension E of wiring board 20 in the direction of the Y-axis (second axis) and the elastic force F generated in wiring board 20 due to the extension. As shown in Fig. 38, the elastic force F of wiring board 20 changes nonlinearly with the amount of extension E.

[0117] In a range e1 where the extension amount E is below a predetermined threshold Eth, the distance between each first fold line W1 and each second fold line W2 increases, and the covering material 27 elastically stretches, causing the wiring board 20 to stretch in the Y-axis direction. The elastic properties of the covering material 27 dominate the extension of the wiring board 20 within the range e1. On the other hand, when the extension amount E reaches the threshold Eth, the insulating substrates 21 and 22 are stretched into a flat plate-like shape. That is, the insulating substrates 21 and 22 are stretched into a flat plate-like shape so that the angles (bending angles) between the connecting lines C1 and C2 are 180°. Therefore, in a range e2 where the extension amount E exceeds the threshold Eth, the elastic force F increases rapidly with increasing extension amount E.

[0118] As explained above, in the range e2 where the extension amount E exceeds the threshold value Eth, the wiring board 20 is less likely to extend than when the extension amount E is within the range e1. That is, the rigidity of the wiring board 20 when the extension amount E is a value within the range e2 exceeds the rigidity of the wiring board 20 when the extension amount E is a value within the range e1. The rigidity of the wiring board 20 is the ratio of the elastic force F to the extension amount E (F / E).

[0119] (9) In the above embodiments, the wiring substrate 20 includes the insulating substrate 21 and the insulating substrate 22. However, one of the insulating substrate 21 and the insulating substrate 22 may be omitted.

[0120] (10) In the above-described embodiments, the wiring substrate 20 includes the insulating substrate 21, the insulating substrate 22, and the conductive layer 23. However, the present disclosure may also be embodied in a resin film that does not include a conductive layer. The resin film is an elastically deformable film-like (e.g., thin plate-like or sheet-like) mounting component, and is formed from a resin material such as polyimide (PI), polyester (PET), polyethylene naphthalate (PEN), or liquid crystal polymer (LCP).

[0121] The shape and characteristics of the resin film are similar to those of the wiring board 20 in each of the above-described embodiments. For example, the resin film is a member including a first surface F1 and a second surface F2 located opposite each other, and in which, in a plan view, a plurality of fold lines W extending along the X axis in a curved wave shape are arranged along the Y axis. The plurality of fold lines W include a first fold line W1 corresponding to the ridge line La of the first surface F1 and the valley line Lb of the second surface F2, and a second fold line W2 corresponding to the valley line Lb of the first surface F1 and the ridge line La of the second surface F2.

[0122] In the resin film exemplified above, the fold lines W corresponding to the ridge lines La or valley lines Lb of the first surface F1 and the second surface F2 are aligned along the Y axis, allowing the resin film to expand and contract in the X and Y directions. This allows the resin film to be deformed into a variety of three-dimensional shapes. Furthermore, the fold lines W corresponding to the ridge lines La and valley lines Lb of the first surface F1 and the second surface F2 are curved and wavy in plan view. Therefore, compared to a configuration in which the fold lines W are straight (e.g., fold lines) in plan view, local stress within the resin film is reduced. This prevents damage to the resin film (e.g., splitting or buckling) due to local stress.

[0123] (11) The term "nth" (n is a natural number) in this application is used only as a formal and convenient label to distinguish each element in the description and does not have any substantive meaning. Therefore, there is no room for restrictive interpretation of the position of each element or the order of production, etc., based on the term "nth."

[0124] J: Supplementary Note From the above-described exemplary embodiments, the following configurations can be understood, for example.

[0125] A method for manufacturing a device according to one aspect (aspect 1) of the present disclosure includes a first step of preparing a wiring board having a flexible insulating base material and a conductive layer formed on the insulating base material, and a second step of covering an object with the wiring board by deforming the wiring board to conform to the three-dimensional shape of the object, wherein the wiring board includes a first surface and a second surface located opposite each other, and a folded structure in which a plurality of folding lines extending along a first axis in a curved wave shape in a planar view are arranged along a second axis intersecting the first axis, each of the first surface and the second surface including a plurality of ridge lines and a plurality of valley lines, each of the plurality of folding lines corresponding to one of the plurality of ridge lines on the first surface and one of the plurality of valley lines on the second surface, or one of the plurality of valley lines on the first surface and one of the plurality of ridge lines on the second surface.

[0126] In the above-described aspect, the plurality of fold lines corresponding to the ridges or valleys of the first and second surfaces are arranged along the second axis, allowing the wiring board to expand and contract in the directions of the first and second axes. Therefore, by flexibly deforming the wiring board to conform to the three-dimensional shape of the object, objects of various three-dimensional shapes can be easily covered with the wiring board. Furthermore, the plurality of fold lines corresponding to the ridges and valleys of the first and second surfaces are curved and wavy in plan view. Therefore, local stress in the conductive layer is reduced compared to an embodiment in which the plurality of fold lines are linear (e.g., folded lines) in plan view. Therefore, damage to the conductive layer (e.g., disconnection or buckling) due to local stress can be suppressed in the second step of deforming the wiring board.

[0127] In a specific example (Aspect 2) of Aspect 1, the first step includes a preparation step of preparing a flat initial base material including the insulating base material and the conductive layer, and a shaping step of forming the folded structure by pressing the initial base material. According to the above aspect, a wiring board having a folded structure can be manufactured by a simple step of pressing the initial base material.

[0128] In a specific example (Aspect 3) of Aspect 2, the press working includes a process of compressing the initial base material with a first compression die having a first molding structure corresponding to the bent structure formed on a first molding surface thereof, and a second compression die having a second molding structure corresponding to the bent structure formed on a second molding surface thereof. According to the above aspect, a wiring board having a bent structure formed thereon can be manufactured by a simple process of compressing the initial base material with the first compression die and the second compression die.

[0129] In a specific example (Aspect 4) of Aspect 2, the press working includes a process of rotating the first pressure roller and the second pressure roller in a state in which the initial base material is disposed between a first pressure roller having a first molding surface on its outer periphery where a first molding structure corresponding to the bent structure is formed, and a second pressure roller having a second molding surface on its outer periphery where a second molding structure corresponding to the bent structure is formed. According to the above aspect, a wiring board having a bent structure formed thereon can be manufactured by a simple process of compressing the initial base material with the first pressure roller and the second pressure roller.

[0130] In a specific example (Aspect 5) of Aspect 3 or Aspect 4, the conductive layer includes a connection terminal exposed from the insulating substrate, and a recess corresponding to the connection terminal is formed in at least one of the first molding surface and the second molding surface. In the above aspect, a recess is formed in at least one of the first molding surface and the second molding surface. In the molding process, the connection terminal is positioned inside the recess, so that a bent structure is not formed in the connection terminal. Therefore, a bent structure can be formed in the wiring substrate while maintaining the surface of the connection terminal as a flat surface. As a result of maintaining the connection terminal as a flat surface, electrical connection between an external device and the connection terminal is facilitated.

[0131] In a wiring board of a specific example (Aspect 6) of any of Aspects 1 to 5, in a cross section perpendicular to the first axis, adjacent ridge lines and valley lines among the plurality of ridge lines and the plurality of valley lines on the first surface are connected by straight lines, and adjacent ridge lines and valley lines among the plurality of ridge lines and the plurality of valley lines on the second surface are connected by straight lines.

[0132] In a specific example (Aspect 7) of any of Aspects 1 to 5, in a cross section perpendicular to the first axis, each of the first surface and the second surface is a continuous wave-like curve across the plurality of bending lines. In the above aspects, in a cross section perpendicular to the first axis, the first surface and the second surface are configured with curves. Therefore, the aforementioned effect of being able to suppress damage (e.g., breakage or buckling) of the conductive layer due to local stress is particularly remarkable.

[0133] In a specific example (Aspect 8) of the wiring board of any one of Aspects 1 to 7, the plurality of fold lines include a plurality of first fold lines and a plurality of second fold lines, each of the plurality of first fold lines corresponds to one of the plurality of ridge lines on the first surface and one of the plurality of valley lines on the second surface, each of the plurality of second fold lines corresponds to one of the plurality of valley lines on the first surface and one of the plurality of ridge lines on the second surface, and each of the plurality of first fold lines and each of the plurality of second fold lines are arranged alternately along the second axis.

[0134] In a wiring board according to a specific example (aspect 9) of aspect 8, a region between each of the plurality of first fold lines and a second fold line among the plurality of second fold lines adjacent to the first fold line has a wave shape in which concave portions and convex portions are alternately arranged along the first axis.

[0135] In a wiring board according to a specific example (aspect 10) of aspect 8 or aspect 9, each of the plurality of first fold lines has a wave shape including a first apex and a first bottom in a planar view, and each of the plurality of second fold lines has a wave shape including a second apex and a second bottom in a planar view, and in a region between a first fold line and a second fold line adjacent to each other in the direction of the second axis among the plurality of first fold lines and the plurality of second fold lines, a portion between the first apex corresponding to the first fold line and the second apex corresponding to the second fold line forms a curved surface that is convex in a third direction perpendicular to the first axis and the second axis, and a portion between the first bottom corresponding to the first fold line and the second bottom corresponding to the second fold line forms a curved surface that is concave in the third direction.

[0136] In the wiring board of Aspect 8 or a specific example (Aspect 11) of Aspect 8, each of the plurality of first fold lines has a wave shape including a first apex and a first bottom in a plan view, each of the plurality of second fold lines has a wave shape including a second apex and a second bottom in a plan view, and in a first region between a first fold line among the plurality of first fold lines and one second fold line adjacent to the first fold line in a first direction along the second axis, a first apex of the first fold line and a second apex of the one second fold line are perpendicular to the first axis and the second axis. a convex portion protruding in three directions, a recess recessed in a fourth direction opposite to the third direction between a first bottom of the first fold line and a second bottom of one of the second fold lines, a recess recessed in the third direction between a first apex of the first fold line and a second apex of the other second fold line in a second region between the first fold line and another second fold line adjacent to the first fold line in a second direction opposite to the first direction, and a convex portion protruding in the third direction between a first bottom of the first fold line and a second bottom of the other second fold line.

[0137] In a specific example (Aspect 12) of the wiring board according to any one of Aspects 1 to 11, each of the plurality of bending lines has a wave shape including a peak and a bottom in a planar view, and a through hole is formed in the insulating substrate at a portion corresponding to at least one of the peak and the bottom of each of the plurality of bending lines. According to the above aspect, a through hole is formed in the insulating substrate at a portion corresponding to the peak or the bottom of each bending line. Therefore, compared to an aspect in which no through hole is formed (e.g., the first embodiment), the flexibility of the wiring board can be improved. That is, in the second embodiment, the wiring board can be easily deformed to follow the three-dimensional shape of an object.

[0138] A method for manufacturing a device according to one aspect of the present disclosure includes a first step of preparing a flexible resin film and a second step of covering an object with the resin film by deforming the resin film to conform to the three-dimensional shape of the object, wherein the resin film includes a first surface and a second surface located opposite each other, and a folded structure in which a plurality of fold lines extending along a first axis in a curved wave shape in a planar view are arranged along a second axis intersecting the first axis, and each of the first surface and the second surface includes a plurality of ridge lines and a plurality of valley lines, and each of the plurality of fold lines corresponds to one of the plurality of ridge lines on the first surface and one of the plurality of valley lines on the second surface, or one of the plurality of valley lines on the first surface and one of the plurality of ridge lines on the second surface.

[0139] 100...covering member, 10...object, 20...wiring board, 21, 22...insulating base material, 23...conductive layer, 24...adhesive, 25...connection terminal, 26...opening, 27...covering material, 30...folding structure, 50, 60...molding device, 51...first compression mold, 52...second compression mold, 61...first pressure roll, 62...second pressure roll, 71...articulation mechanism, 72...rotation mechanism, 73...wiring structure.

Claims

1. A method for manufacturing a device comprising: a first step of preparing a wiring board having a flexible insulating base material and a conductive layer formed on the insulating base material; and a second step of covering an object with the wiring board by deforming the wiring board to conform to the three-dimensional shape of the object, wherein the wiring board has: a first surface and a second surface located opposite each other; and a folded structure in which a plurality of folding lines extending along a first axis in a curved wave shape in a plan view are arranged along a second axis intersecting the first axis, each of the first surface and the second surface including a plurality of ridge lines and a plurality of valley lines, each of the plurality of folding lines corresponding to one of the plurality of ridge lines on the first surface and one of the plurality of valley lines on the second surface, or one of the plurality of valley lines on the first surface and one of the plurality of ridge lines on the second surface.

2. A method for manufacturing a device according to claim 1, wherein the first step includes a preparation step of preparing a flat initial substrate including the insulating substrate and the conductive layer, and a molding step of forming the bent structure by pressing the initial substrate.

3. A method for manufacturing the device of claim 2, wherein the press processing includes a process of compressing the initial base material using a first compression mold having a first molding structure corresponding to the bent structure formed on a first molding surface, and a second compression mold having a second molding structure corresponding to the bent structure formed on a second molding surface.

4. A method for manufacturing the device of claim 2, wherein the press processing includes a process of rotating the first pressure roller and the second pressure roller, with the initial base material being positioned between a first pressure roller having a first forming structure corresponding to the folded structure formed on a first forming surface of the outer periphery, and a second pressure roller having a second forming structure corresponding to the folded structure formed on a second forming surface of the outer periphery.

5. A method for manufacturing a device according to claim 3 or claim 4, wherein the conductive layer includes a connection terminal exposed from the insulating substrate, and a recess corresponding to the connection terminal is formed in at least one of the first molding surface and the second molding surface.

6. A method for manufacturing a device comprising: a first step of preparing a flexible resin film; and a second step of covering an object with the resin film by deforming the resin film to conform to the three-dimensional shape of the object, wherein the resin film has a first surface and a second surface located opposite each other, and a folded structure in which a plurality of fold lines extending along a first axis in a curved wave shape in a plan view are arranged along a second axis intersecting the first axis, each of the first surface and the second surface including a plurality of ridge lines and a plurality of valley lines, and each of the plurality of fold lines corresponds to one of the plurality of ridge lines on the first surface and one of the plurality of valley lines on the second surface, or one of the plurality of valley lines on the first surface and one of the plurality of ridge lines on the second surface.

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