JP2018049854A - Wiring structure and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional wiring structure which has high degree of freedom in arranging wiring lines and can suppress an increase in wiring resistance.SOLUTION: The wiring structure includes: a laminated part in which a first material having insulating properties with an opening portion is laminated, the opening portion having a common portion in plan view with an opening of upper and lower adjacent layers; and a wiring portion having a conductive integral structure which penetrates through the opening and whose tip is exposed at the opening at a penetrating end.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a three-dimensional additive manufacturing technique, and more particularly to a technique for forming a wiring structure using a 3D printer.

  3D CAD (Computer Aided Design) data is divided into layers, and a layer is attached to each divided layer while adding materials so that the layers are stacked on top of each other. In the international standard, it is defined as Additive Manufacturing. This manufacturing method invented in the 1980's is generally called a 3D printer (3D printer). In recent years, 3D printers are attracting attention as a new manufacturing method because they can produce complex shapes without using a mold if there is 3D CAD data.

  In 3D printers, shapes that were once difficult to manufacture, such as mesh shapes and porous shapes, can be easily and accurately manufactured, unlike removal processing by cutting and molding processing in which a material is poured into a mold and hardened. Furthermore, it is also expected to enable modeling in which a plurality of types of materials are freely arranged in the same layer. This is because a three-dimensional structure having a new function utilizing the characteristics of each material can be realized by modeling using a plurality of materials.

  For example, a three-dimensional structure having a function of an electronic circuit is realized by combining a conductive material and an insulating material. In addition, by combining a hard material and a flexible material, a three-dimensional structure having a function having both strength and flexibility can be realized. These functions can be realized without developing new materials.

  Patent Document 1 discloses a technique for reducing a connection failure between an electrical conduction path (corresponding to a via) for connecting upper and lower conductive layers and a conductive layer in a multilayer wiring board formed by a 3D printer. According to Patent Document 1, when the conductive layers positioned above and below the insulating layer are connected by the electrical conduction path penetrating the insulation layer, the connection between the upper conductive layer and the electrical conduction path is The conductive path is projected above the surface of the insulating layer, and the protruding part of the electrical path is covered with the upper conductive layer and joined.

  Patent Document 2 discloses a method for manufacturing a three-dimensional wiring structure having an electronic circuit function. According to this method, after forming the ceramic green sheet, via holes for forming wiring are formed by a method such as punching or laser processing. Thereafter, a via electrode is formed by filling the via hole with a conductive paste, and a wiring pattern such as an electrode is printed by a screen printing method.

Japanese Patent Laying-Open No. 2015-135933 JP 2004-273426 A

  However, the technique disclosed in Patent Document 1 has the following problems. That is, when the number of layers of the multilayer wiring increases and the number of electrical conduction paths connected in the stacking direction increases, the connection resistance is integrated, resulting in an increase in resistance of the electrical conduction path. Furthermore, since the electrical conduction path is formed in a direction perpendicular to the plane of the layers, the connection at the shortest distance is not possible when the projections of the conductive layers to be connected are shifted in plan view. For this reason, when the conductive path is detoured, the wiring becomes longer and the resistance is increased.

  Further, in the technique disclosed in Patent Document 2, via holes are formed by punching or laser processing, so that via holes in the vertical direction can be formed on the ceramic green sheet surface, but they cannot be formed in an oblique direction. For this reason, the arrangement of the wiring is limited, and similarly to Patent Document 1, there is a problem that the wiring becomes long and the resistance is increased.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a three-dimensional wiring structure that has a high degree of freedom in arranging wiring and can suppress an increase in wiring resistance. .

  In the wiring structure of the present invention, a first material having insulating properties is laminated with an opening, and the opening has a laminated portion having a common portion in plan view with an opening of an adjacent layer above and below, A wiring portion having a conductive integral structure that penetrates the opening and has a tip exposed at the opening at the end of the opening.

  In the method for manufacturing a wiring structure according to the present invention, the first material having an insulating property has an opening, and the opening has a common portion in plan view with the openings of adjacent layers above and below. Then, a laminated wiring having a conductive integrated structure is passed through the opening, and the tip of the wiring is exposed at the opening at the end of the wiring.

  ADVANTAGE OF THE INVENTION According to this invention, the freedom degree which arrange | positions wiring is high and the three-dimensional wiring structure which can suppress the increase in wiring resistance is provided.

It is sectional drawing which shows the structure of the wiring structure of the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing explaining the manufacturing process of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing explaining the manufacturing process of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing explaining the manufacturing process of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing explaining the manufacturing process of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing explaining the manufacturing process of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing explaining the manufacturing process of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing explaining the manufacturing process of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing explaining the manufacturing process of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing explaining another manufacturing process of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing explaining another manufacturing process of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing explaining another manufacturing process of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing explaining another manufacturing process of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing explaining another manufacturing process of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing which shows the structure (when a wiring part is a perpendicular direction) of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing which shows the structure (when a wiring part is an in-plane direction) of the wiring structure of the 2nd Embodiment of this invention. It is a schematic diagram which shows the structure (when a wiring part is various directions) of the wiring structure of the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the modification of the wiring structure of the 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the preferred embodiments described below are technically preferable for carrying out the present invention, but the scope of the invention is not limited to the following.
(First embodiment)
FIG. 1 is a cross-sectional view showing the configuration of the wiring structure according to the first embodiment of the present invention. In the wiring structure 1 of the present embodiment, a first material having insulating properties is laminated with an opening 14, and the opening 14 has a common portion in plan view with the openings 14 in the upper and lower adjacent layers. It has the laminated part 11 which has. Furthermore, it has the wiring part 13 which has the electroconductive integral structure which penetrates the said opening part 14 and the front-end | tip is exposed by the said opening part 14 of the penetrated end.

  The manufacturing method of the wiring structure 1 according to the present embodiment has an opening 14 made of an insulating first material, and the opening 14 is common to the openings 14 of the layers adjacent to each other in plan view. Have a part and stack. Further, a wiring having a conductive integrated structure is passed through the opening 14, and the tip of the wiring is exposed at the opening 14 at the end of the wiring.

  According to the wiring structure 1, the wiring portion 13 that becomes a wiring can be arranged in an arbitrary direction depending on the direction in which the openings 14 are continuously connected. Thereby, wiring at the shortest distance is possible. Furthermore, since the wiring part 13 is an integral structure and there is no connection part inside, connection resistance does not arise. As a result, according to the wiring structure 1, the wiring resistance can be reduced.

As described above, according to the present embodiment, there is provided a three-dimensional wiring structure that has a high degree of freedom in arranging wiring and can suppress an increase in wiring resistance.
(Second Embodiment)
FIG. 2 is a cross-sectional view showing the configuration of the wiring structure according to the second embodiment of the present invention. The wiring structure 2 of the present embodiment includes a stacked portion 21 having a first material having insulation, a connection portion 22 having a second material having conductivity, and a third material having conductivity. Wiring part 23.

  The laminated portion 21 has a first material laminated with an opening 24 to mount an electronic component. The opening 24 is continuous with the opening 24 of the layer adjacent to the upper and lower sides with a common part in plan view. The connection part 22 is connected to the electrode of the electronic component through the opening 24. Furthermore, the wiring part 23 is provided through the opening 24 and is connected to the connection part 22 through the opening 24 at the penetrating end.

  The first material has an insulating property. This material is typically plastic. Specific examples include ABS (acrylonitrile butadiene styrene), polycarbonate, polylactic acid, acrylic, polyetherimide, polyphenylsulfone, nylon, polyethylene, silicone, and epoxy, but are not limited thereto.

  As a method for laminating the first material, a method classified as an additive manufacturing method by ASTM (American Society for Testing and Materials) can be used. For example, there is a material extrusion method that extrudes from an opening such as a nozzle and deposits on a modeling stage. Further, as another method, there is a material jetting method (Material jetting) in which droplets of the first material are jetted and selectively cured.

  In the material extrusion method, a layer having a thickness of about 0.8 mm can be laminated, but is not limited thereto. In the material injection method, a layer having a thickness of about 0.2 mm can be stacked, but the present invention is not limited to this.

  Regarding the melting and curing of the first material, if it is a thermoplastic resin, a predetermined amount of the melted material can be supplied to a predetermined position and cured by air cooling. In the case of thermosetting or photo-curing resin, it is cured and laminated by jetting material droplets, heating if it is a thermosetting resin, or irradiating UV light etc. if it is a photo-curing resin. Can do.

  The second material has conductivity. The melting point of the second material is preferably lower than the melting point of the first material. Examples of the second material include, but are not limited to, silver nano paste, silver nano ink, and solder paste. When the electrode of the electronic component and the wiring part 23 are connected with the second material, the second material is heated and melted to increase the fluidity, and the adhesion between the electrode and the wiring part 23 is strengthened by solidification by subsequent cooling. be able to.

  The third material has conductivity. Examples of this material include, but are not limited to, copper, silver, and aluminum. The melting point of the third material can be higher than the melting point of the first material, but is not limited thereto. The third material has a monolithic structure, does not have a connection portion inside, and can have a flexible thin wire shape, a filler shape, or a plate shape.

  The third material constitutes the wiring portion 23, and the outer periphery of the projection image of the wiring portion 23 when the wiring structure 2 is viewed in plan is present inside the outer periphery of the projection image of the opening 24. Therefore, for example, when the inner diameter of the opening 24 is 0.4 mm, the wiring portion 23 can be a thin wire having an inner diameter of 0.3 mm, but is not limited thereto.

  The wiring structure 2 is mounted with an electronic component having electrodes with the above configuration. The electronic component can be an arbitrary electronic component such as an IC (Integrated Circuit), a capacitor, various display elements, various sensors, a small motor, or a transformer.

  Next, a method for manufacturing the wiring structure 2 will be described. 3A to 3H are cross-sectional views illustrating the manufacturing process of the wiring structure 2 of this embodiment. In this manufacturing process, the laminated portion 21 made of the first material is formed by a 3D printer.

  In FIG. 3A, a layer of a first material is stacked on a stage by a 3D printer, and an electronic component is placed at a predetermined position on the layer of the first material. The electronic component may be arranged directly on the stage.

  In FIG. 3B, the layer of the first material is laminated by the 3D printer until the surface of the electrode of the electronic component is as high as the surface of the laminated surface.

  In FIG. 3C, the 2nd material which comprises the connection part 22 is apply | coated to the predetermined position which touches the surface of an electrode. Application | coating of a 2nd material may use a 3D printer or another coating device. The application of the second material may be performed through the hole 25 after the hole 25 formed by the continuous opening 24 in FIG. 3D described later is formed. In this case, a method of passing a pipe or the like through the hole 25 and pouring and applying a fluid second material to the surface of the connection portion 22 through the pipe is possible.

  In FIG. 3D, the first material is laminated with the opening 24 continuous from the connection portion 22 by the 3D printer, and the hole 25 penetrating from the connection portion 22 to the lamination surface is formed. Here, as shown in FIG. 3D, when the opening 24 is continued obliquely, it is necessary to form a portion that protrudes from the end of the lower layer, such as a portion A in the drawing. In this case, since the first material has viscosity, the portion A can be formed during lamination. The first material is laminated with a portion A and then cured.

  In FIG. 3E, the wiring part 23 having the third material is inserted into the hole 25, and the end of the wiring part 23 is connected to the connection part 22. At the time of connection, the stage can be heated to melt the connection portion 22 and then cooled and solidified. Thereby, the electrical connection between the electrode and the wiring portion 23 can be improved.

  In FIG. 3F, the connection portion 22 is applied to the other end portion of the wiring portion 23 at the opening portion 24. Application | coating of a 2nd material may use a 3D printer or another coating device.

  In FIG. 3G, an electrode is connected to the connection part 22 and another electronic component is mounted. At the time of connection, the stage can be heated to melt the connection portion 22 and then cooled and solidified. Thereby, the electrical connection between the electrode and the wiring portion 23 can be improved.

  In FIG. 3H, the layer of the first material is laminated by the 3D printer until the surface of the electronic component is as high as the surface of the laminated surface. Note that the surface of the laminated surface does not have to be the same level as the surface of the electronic component, and can be set at an arbitrary position.

  As described above, the manufacturing method of the wiring structure 1 according to the present embodiment includes the opening 24 in the first material having insulation, and the opening 24 is the opening 24 in the layer adjacent to the top and bottom. And having a common part in a plan view and stacking. Further, a wiring having a conductive integral structure is inserted into the opening 24 so that the opening 24 at the inserted end can be connected to the electrode of the electronic component. Further, the second material having conductivity is connected to the wiring through the opening 24 at the end where the wiring is inserted.

  In addition, the wiring part 23 is not limited to be formed by inserting the metal previously processed into an integrated thin line shape or the like into the hole 25 formed by the continuous opening 24 as described above. The wiring part 23 is formed by melting the second material used for the connection part 22 and pouring it into the hole 25, and then cooling and solidifying it. Also good. Also by this method, it is possible to form the wiring portion 23 having an integral structure and no connection portion inside.

  Next, another method for manufacturing the wiring structure 2 will be described. 4A to 4E are cross-sectional views illustrating another manufacturing process of the wiring structure 2 according to the present embodiment. In this manufacturing process, the laminated portion 21 made of the first material is formed by a 3D printer.

  In FIG. 4A, the layer of the first material is laminated on the stage by the 3D printer, and the laminated portion 21 configured to place the electronic component at a predetermined position is formed. The central layer of the sectional view that defines the opening 24 appears to be floating in the air, but in the portion away from the opening 24 in the front direction or the depth direction of the paper surface, Each layer is continuous. In addition, when forming the portion B in the figure, a base material like C is set, and after forming the laminated portion 21, the base material of C is removed when removing the laminated portion 21 from the stage. You may do it.

  In FIG. 4B, the wiring portion 23 is inserted into the opening 24 after the stacked portion 21 is removed from the stage.

  In FIG. 4C, the second material constituting the connection portion 22 is applied to the openings 24 at both ends of the wiring portion 23 in contact with both ends of the wiring portion 23. Application | coating of a 2nd material may use a 3D printer or another coating device. In addition, you may make it the 2nd material which comprises the connection part 22 apply | coat to the electrode of the electronic component in FIG. 4D mentioned later.

  In FIG. 4D and FIG. 4E, the electronic component is aligned and mounted at the position where the electronic component provided in the stacked portion 21 is mounted. At this time, the electrode of the electronic component is connected to the wiring part 23 via the connection part 22. At the time of connection, the stage can be heated to melt the connection portion 22 and then cooled and solidified. Thereby, the electrical connection between the electrode and the wiring portion 23 can be improved.

  As described above, the manufacturing method of the wiring structure 1 according to the present embodiment includes the opening 24 in the first material having insulation, and the opening 24 is the opening 24 in the layer adjacent to the top and bottom. And having a common part in a plan view and stacking. Further, a wiring having a conductive integral structure is inserted into the opening 24 so that the opening 24 at the inserted end can be connected to the electrode of the electronic component. Further, the second material having conductivity is connected to the wiring through the opening 24 at the end where the wiring is inserted.

  FIG. 5 is a cross-sectional view showing a case where the wiring portion is formed in a direction perpendicular to the in-plane direction of the stacked portion in the configuration of the wiring structure according to the present embodiment. In the wiring structure 3, the wiring part 33 in the vertical direction with respect to the in-plane can be formed by continuing the opening part 34 of the stacked part 31 provided on the connection part 32 in the vertical direction.

  FIG. 6 is a cross-sectional view showing a case where the wiring portion is formed in the in-plane direction of the laminated portion in the configuration of the wiring structure according to the present embodiment. In the wiring structure 4, the wiring portion 43 in the in-plane direction can be formed by extending the opening 44 of the stacked portion 41 provided on the connection portion 42 in the in-plane direction. At this time, the wiring part 43 can connect electrodes by combining a linear part and a curved part along the opening part 44 provided in the surface of the lamination | stacking part 41. FIG. This is possible because the wiring portion 43 has a flexible thin wire shape or the like.

  FIG. 7 is a schematic diagram showing a case where the wiring portion is in various directions in the configuration of the wiring structure according to the present embodiment. In the wiring structure 5, the direction in which the openings of the laminated portion 51 are continuous can be arbitrarily set, and thus a plurality of wiring portions 53 in various directions can be provided. As a result, the positions and orientations of the plurality of electronic components mounted on the stacked unit 51 can be arbitrarily set. Thereby, a complicated wiring structure or a small wiring structure can be configured.

  In addition, the wiring part 53 is not limited to connecting to the electrode of an electronic component. The wiring part 53 can also be connected to an electrode such as a circuit provided inside or on the surface of the laminated part 51.

  FIG. 8 is a cross-sectional view showing a configuration of a modified example of the wiring structure according to the present embodiment. The wiring structure 6 is characterized by having a filler 65 in a space excluding the wiring portion 63 of the opening 64.

  The filler 65 can be an adhesive. As an adhesive agent, the epoxy resin which is a thermosetting resin with a low viscosity in a molten state is mentioned, for example. Since the epoxy resin has a low viscosity, it can be injected in detail by capillary action.

  Epoxy resin is stored frozen and thawed naturally at room temperature. The naturally thawed epoxy resin is injected into the opening 64 in which the wiring part 63 is inserted while being pressurized with air by a dispenser or the like. Epoxy resin can be injected at room temperature, but the temperature of the resin may be raised in order to increase filling properties. Moreover, rigidity can also be raised by mix | blending a silica filler about 10 micrometers in length with an epoxy resin.

  In the step of curing the epoxy resin filled in the opening 64 after the injection, it is desirable to cure at a temperature equal to or lower than the thermal deformation temperature of the first material in order to prevent thermal deformation of the first material constituting the laminated portion 61. . For example, when a polyether sulfone resin having a thermal deformation temperature of about 203 ° C. is used as the first material, it can be cured at 203 ° C. or lower.

  Epoxy resins are excellent in mechanical strength and adhesiveness such as tensile strength, bending strength, flexural modulus and Izod impact strength. Therefore, there is an effect that the adhesion between the laminated portion 61, the connecting portion 62, and the wiring portion 63 is strengthened, and the overall mechanical strength of the wiring structure 6 is increased.

  The filler 65 is not limited to an epoxy resin, and may be other materials such as a phenol resin, a silicon resin, and an acrylic resin. Even when these materials are used, the adhesion between the laminated portion 61, the connecting portion 62, and the wiring portion 63 is strengthened according to the characteristics of each material, and the overall mechanical strength of the wiring structure 6 is increased. it can. As described above, by increasing the adhesion and increasing the mechanical strength, for example, the occurrence of troubles such as disconnection between the wiring part and connection part during long-term use or vibration is suppressed, improving reliability. Can be made.

  According to the wiring structure of this embodiment, the wiring part which becomes wiring can be arrange | positioned in arbitrary directions according to the direction which connects an opening part continuously. Thereby, wiring at the shortest distance is possible. Furthermore, since the wiring portion is an integral structure and there is no connection portion inside, no connection resistance is generated. As a result, according to the wiring structure of this embodiment, the wiring resistance can be reduced.

  As described above, according to the present embodiment, there is provided a three-dimensional wiring structure that has a high degree of freedom in arranging wiring and can suppress an increase in wiring resistance.

  The present invention is not limited to the above embodiment, and various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention.

Moreover, although a part or all of said embodiment may be described also as the following additional remarks, it is not restricted to the following.
(Appendix 1)
A first material having insulating properties is laminated with an opening, and the opening has a laminated portion having a common part in plan view with an opening of a layer adjacent to the upper and lower sides,
A wiring structure having a conductive integrated structure that penetrates through the opening and has a tip exposed at the opening at the end of the opening.
(Appendix 2)
The wiring structure according to appendix 1, comprising a second material having conductivity, and having a connection portion connected to the wiring portion at the opening at an end through which the wiring portion passes.
(Appendix 3)
The wiring structure according to appendix 2, wherein the connection portion is melted and solidified by the second material and connected to the wiring portion.
(Appendix 4)
The wiring structure according to attachment 2 or 3, wherein the second material has a melting point lower than that of the first material.
(Appendix 5)
The wiring structure according to any one of appendices 2 to 4, wherein the second material has fluidity.
(Appendix 6)
The wiring structure according to any one of appendices 1 to 5, wherein the wiring portion has a thin line shape, a pillar shape, or a plate shape.
(Appendix 7)
The wiring structure according to any one of appendices 1 to 6, wherein the opening has a filler in a space excluding the wiring portion.
(Appendix 8)
The wiring structure according to appendix 7, wherein the filler bonds the laminated portion and the wiring portion.
(Appendix 9)
A first material having insulating properties, having an opening, and the opening has a common portion in plan view with an opening of a layer adjacent to the top and bottom;
A method for manufacturing a wiring structure, wherein a wiring having a conductive integrated structure is passed through the opening, and the tip of the wiring is exposed at the opening at the end of the wiring.
(Appendix 10)
The method for manufacturing a wiring structure according to appendix 9, wherein the second material having conductivity is connected to the wiring through the opening at the end where the wiring is penetrated.
(Appendix 11)
The method for manufacturing a wiring structure according to appendix 10, wherein the second material is melted and solidified and connected to the wiring portion.
(Appendix 12)
The method for manufacturing a wiring structure according to appendix 10 or 11, wherein the second material has a melting point lower than that of the first material.
(Appendix 13)
13. The method for manufacturing a wiring structure according to one of appendices 10 to 12, wherein the second material has fluidity.
(Appendix 14)
14. The method for manufacturing a wiring structure according to one of appendices 9 to 13, wherein the wiring has a thin wire shape, a pillar shape, or a plate shape.
(Appendix 15)
15. The method for manufacturing a wiring structure according to any one of appendices 9 to 14, wherein a filler is inserted into a space excluding the wiring in the opening.
(Appendix 16)
The method for manufacturing a wiring structure according to appendix 15, wherein the first material and the wiring are bonded with the filler.

1, 2, 3, 4, 5, 6 Wiring structure 11, 21, 31, 41, 51, 61 Laminated portion 22, 32, 42, 62 Connection portion 13, 23, 33, 43, 53, 63 Wiring portion 14 24, 34, 44, 64 Opening 25 Hole 65 Filler

Claims (10)

A first material having insulating properties is laminated with an opening, and the opening has a laminated portion having a common part in plan view with an opening of a layer adjacent to the upper and lower sides,
A wiring structure having a conductive integrated structure that penetrates through the opening and has a tip exposed at the opening at the end of the opening.   The wiring structure according to claim 1, comprising a second material having conductivity, and having a connection portion connected to the wiring portion at the opening at an end through which the wiring portion passes.   The wiring structure according to claim 2, wherein the connection portion is melted and solidified by the second material and connected to the wiring portion.   The wiring structure according to claim 2, wherein the second material has a melting point lower than that of the first material.   The wiring structure according to claim 2, wherein the second material has fluidity.   The wiring structure according to claim 1, wherein the wiring portion has a thin line shape, a pillar shape, or a plate shape.   The wiring structure according to claim 1, further comprising a filler in a space excluding the wiring portion of the opening.   The wiring structure according to claim 7, wherein the filler bonds the laminated portion and the wiring portion. A first material having insulating properties, having an opening, and the opening has a common portion in plan view with an opening of a layer adjacent to the top and bottom;
A method for manufacturing a wiring structure, wherein a wiring having a conductive integrated structure is passed through the opening, and the tip of the wiring is exposed at the opening at the end of the wiring.   The method for manufacturing a wiring structure according to claim 9, wherein the second material having conductivity is connected to the wiring through the opening at the end where the wiring is penetrated.

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