WO2016208093A1

WO2016208093A1 - Three-dimensional wiring board and method for producing three-dimensional wiring board

Info

Publication number: WO2016208093A1
Application number: PCT/JP2015/084958
Authority: WO
Inventors: 道脇　茂
Original assignee: 株式会社メイコー
Priority date: 2015-06-24
Filing date: 2015-12-14
Publication date: 2016-12-29
Also published as: WO2016208651A1; JP6014792B1; JPWO2016208090A1; WO2016208092A1

Abstract

A three-dimensional wiring board is provided with a three-dimensional shape and comprises a resin film (2) having a breaking elongation of 50% or more and a wiring pattern (3) that is formed on the surface of the resin film (2) and that is provided with a desired pattern. The resin film (2) comprises rigid sections (1a, 1b) provided with a three-dimensional shape and a flexible section (1c) that is flexible and that extends in a desired direction from the ends of the rigid sections.

Description

Three-dimensional wiring board and method for manufacturing three-dimensional wiring board

The present invention relates to a three-dimensional wiring board having a three-dimensionally formed rigid portion and a flexible portion, and a method for manufacturing the same.

A conventionally known three-dimensional wiring board is a MID (Molded Interconnect Device) substrate, which is a component in which an electric circuit is directly and three-dimensionally formed on the surface of a structure having a three-dimensional structure. As techniques relating to the MID substrate, methods such as a two-shot method, MIPTEC (Microscopic Integrated Processing Technology), and LDS (Laser Direct Direct Structure) are known. In any method, after a three-dimensional structure is formed on the mold resin, a wiring circuit is formed on the surface. For example, Patent Document 1 discloses a technique related to an MID substrate and its manufacture.

In the two-shot method, secondary molding with a new resin is performed on a portion of the molded resin that is not molded on the primary molding, and a catalyst is applied and plated using the resin for the secondary molding as a resist. Thus, a wiring circuit is formed on the mold resin. However, since the shape of the wiring pattern is regulated by the secondary molded resin, the minimum L / S (line width and spacing) indicating the conductor width and the conductor gap is limited due to the limit of the mold processing accuracy for the secondary molding. The value was about 150/150 μm, and it was difficult to form a finer wiring pattern.

In MIPTEC, the entire surface of the molded mold resin is metalized, and the metal (metalizing layer) at the outer edge portion of the wiring circuit is removed by laser light. Thereafter, a region to be a wiring circuit is energized to perform electroplating, and then the entire surface of the molded body is subjected to flash etching to remove metals other than the wiring circuit, thereby forming a wiring circuit on the mold resin. However, when using laser light, a special laser irradiation apparatus corresponding to the three-dimensional shape of the molded mold resin is required, and there is a problem of increase in manufacturing cost due to labor of laser processing and equipment investment. In addition, since the metal necessary for the wiring circuit is deposited by electrolytic plating, it is necessary to energize only the region that becomes the wiring circuit, so that the region that becomes the wiring circuit is electrically connected to the outer periphery of the molded body. Or have to be electrically connected to the outer periphery via a feeder line. That is, there is a problem that it is difficult to electrically separate the region to be the wiring circuit from the outer peripheral portion of the molded body (that is, formation of an independent wiring pattern), and formation of a feed line that is finally unnecessary as a circuit and The problem of increased cost associated with removal arises.

In LDS, primary molding is performed using a special resin material containing conductive particles, the region that becomes the wiring circuit is irradiated with laser light to expose the conductive particles, and the exposed portions of the conductive particles are plated. As a result, a wiring circuit is formed on the mold resin. However, the minimum value of L / S is about 100/150 μm because of the problem of accuracy of exposing the conductive particles in the molded mold resin, and it is difficult to form a finer wiring pattern. In addition, a special laser irradiation device is required as in MIPTEC, and there is a problem of increased manufacturing costs due to labor of laser processing and capital investment.

In any of the above methods, the wiring circuit is formed on the mold resin having a three-dimensional shape, so that the finally manufactured MID substrate is a single-sided substrate. For this reason, the freedom degree of a wiring circuit becomes small compared with a double-sided board, and the problem that size reduction of board | substrate itself becomes difficult arises. As a method for solving the problem and the above-described problem, there is a method of manufacturing a three-dimensional wiring board by forming a wiring circuit on a thermoplastic resin such as polyimide and then bending the resin by heating and pressing. For example, Patent Document 2 discloses that a metal foil is pasted on a polyimide film by thermocompression bonding, and then three-dimensional molding is disclosed, and Patent Document 3 discloses that a three-dimensional molding is performed after applying a conductive paste on a polysulfone resin. It is disclosed.

JP 2012-94605 A Japanese Patent Laid-Open No. 06-188537 JP 2000-174399 A

However, after three-dimensional molding, although the three-dimensional shape can be maintained due to rigidity, it becomes difficult to use as a flexible substrate because flexibility is lost, and the use of the three-dimensional molded substrate is limited to the use as a rigid substrate. End up. In addition, when electrically connecting three-dimensional molded substrates that are located apart from each other, it is necessary to electrically connect via connection parts such as wiring wires, another flexible substrate, or another rigid substrate. As a result, it is difficult to reduce the cost by reducing the number of parts and to properly arrange a three-dimensional wiring board corresponding to a device housing having a narrow space or a three-dimensional shape.

The present invention has been made in view of such problems, and the object of the present invention is to have flexibility, cost reduction, and good compatibility with equipment casings having a narrow space or a three-dimensional shape. An object of the present invention is to provide a three-dimensional wiring board that can be easily arranged and a method for manufacturing the same.

In order to achieve the above object, a three-dimensional wiring board of the present invention has a three-dimensional shape and has a resin film having a breaking elongation of 50% or more, and a wiring having a desired pattern formed on the surface of the resin film. The resin film includes a rigid portion having the three-dimensional shape, and a flexible portion extending in a desired direction from an end portion of the rigid portion and having flexibility.

Moreover, in order to achieve the said objective, the manufacturing method of the three-dimensional wiring board of this invention forms the 1st metal film on the surface of the preparatory process which prepares the resin film provided with 50% or more elongation at break, and the said resin film A first metal film forming step, a pattern forming step of patterning the first metal film by photolithography to form a desired pattern, and a three-dimensional molding by heating and pressurizing the resin film. Forming a wiring pattern by laminating a second metal film on the patterned first metal film, and the three-dimensional molding process is a rigid having a three-dimensional shape. And a flexible portion extending in a desired direction from the end portion of the rigid portion and the flexible portion is formed on the resin film.

According to the present invention, there is provided a three-dimensional wiring board that has flexibility, can reduce costs, and can be favorably arranged corresponding to a device casing having a narrow space or a three-dimensional shape, and a method for manufacturing the same. can do.

It is a perspective view of the three-dimensional wiring board which concerns on the Example of this invention. It is sectional drawing in the manufacturing process of the three-dimensional wiring board which concerns on the Example of this invention. It is sectional drawing in the manufacturing process of the three-dimensional wiring board which concerns on the Example of this invention. It is the schematic in metal film formation about the three-dimensional wiring board which concerns on the Example of this invention. It is sectional drawing in the manufacturing process of the three-dimensional wiring board which concerns on the Example of this invention. It is an expansion conceptual diagram of the broken-line area | region VI in FIG. It is the schematic in metal film formation about the three-dimensional wiring board which concerns on the Example of this invention. It is the schematic in metal film formation about the three-dimensional wiring board which concerns on the Example of this invention. It is the schematic in metal film formation about the three-dimensional wiring board which concerns on the Example of this invention. It is sectional drawing in the manufacturing process of the three-dimensional wiring board which concerns on the Example of this invention. It is an expansion conceptual diagram of the broken-line area | region XI in FIG. It is the schematic in metal film formation about the three-dimensional wiring board which concerns on the Example of this invention. It is sectional drawing in the manufacturing process of the three-dimensional wiring board which concerns on the Example of this invention. It is the schematic which shows the manufacturing process which concerns on the three-dimensional shaping | molding which concerns on the Example of this invention. It is the schematic which shows the manufacturing process which concerns on the three-dimensional shaping | molding which concerns on the Example of this invention. It is the schematic which shows the manufacturing process which concerns on the three-dimensional shaping | molding which concerns on the Example of this invention. It is the schematic which shows the manufacturing process which concerns on the three-dimensional shaping | molding which concerns on the Example of this invention. It is a perspective view in the manufacturing process of the three-dimensional wiring board which concerns on the Example of this invention. It is sectional drawing in the manufacturing process of the three-dimensional wiring board which concerns on the Example of this invention. It is an expansion conceptual diagram of the broken-line area | region XX of FIG. It is sectional drawing in the manufacturing process of the three-dimensional wiring board which concerns on the Example of this invention. It is an expansion conceptual diagram of the broken-line area | region XXII in FIG. It is the schematic in metal film formation about the three-dimensional wiring board which concerns on the Example of this invention. It is a perspective view of the three-dimensional wiring board which concerns on the modification of this invention.

Hereinafter, with reference to the drawings, embodiments of the present invention will be described in detail based on examples. In addition, this invention is not limited to the content demonstrated below, In the range which does not change the summary, it can change arbitrarily and can implement. The drawings used to describe the embodiments schematically show the three-dimensional wiring board and its constituent members according to the present invention, and are partially emphasized, enlarged, reduced, omitted or the like for the purpose of deepening understanding. In some cases, it does not accurately represent the scale, shape, etc. of the three-dimensional wiring board and its constituent members. Furthermore, various numerical values used in the embodiments may be examples, and can be changed variously as necessary.

<Example>
First, the structure of the three-dimensional wiring board 1 according to the present embodiment will be described with reference to FIG. Here, FIG. 1 is a perspective view of the three-dimensional wiring board 1 according to the present embodiment.

As shown in FIG. 1, the three-dimensional wiring board 1 according to the present embodiment has two

rigid parts

1a and 1b that are three-dimensionally molded and a flexible part 1c that connects (couples) the two rigid parts 1a and 1b. is doing. The flexible portion 1c is not three-dimensionally molded, has flexibility, and can be bent in a desired direction. That is, by bending the flexible portion 1c, it is possible to freely adjust the positional relationship between the two

rigid portions

1a and 1b, which is suitable for a device housing having a narrow space or a three-dimensional shape. The arrangement of the three-dimensional wiring board 1 can be achieved. Further, as shown in FIG. 1, the three-dimensional wiring board 1 has different dimensions (that is, heights) in the Z direction at the respective positions in the X direction and the Y direction, and irregularities are formed on the XY plane. .

In addition, the rigid part in this invention does not necessarily have hardness and intensity | strength like the rigid board which is 1 type of a general printed wiring board, but the shape is being fixed compared with a flexible part. Defined by meaning. That is, the

rigid portions

1a and 1b in the present embodiment are not the same as the rigid portions constituting a general rigid substrate or a general rigid flexible substrate, but are defined as portions corresponding to the rigid portions constituting the rigid flexible substrate. Has been. The

rigid portions

1a and 1b in the present embodiment are softer than a general rigid substrate and harder than a general flexible substrate.

Further, as shown in FIG. 1, the three-dimensional wiring board 1 has a thermoplastic resin film 2 and a wiring pattern 3 formed on both surfaces of the thermoplastic resin film 2 (only one surface is shown in FIG. 1). Yes. Moreover, since the thermoplastic resin film 2 is used as a base material of the three-dimensional wiring board 1,

rigid parts

2a, 2b and flexible parts corresponding to the

rigid parts

1a, 1b and the flexible part 1c of the three-dimensional wiring board 1. 2c is included. That is, the thermoplastic resin film 2 is composed of

rigid portions

2a and 2b that are three-dimensionally molded and a flexible portion 2c that is not three-dimensionally molded and has flexibility. Here, the flexible portion 2c extends in a desired direction (in this embodiment, toward the other rigid portion) from the ends of the

rigid portions

2a and 2b, and connects the two rigid portions 2a and 2b. is doing.

As the thermoplastic resin film 2, for example, a known resin film such as polyimide or polyethylene terephthalate can be used. There is no limitation in the thickness of the thermoplastic resin film 2, and it can change suitably according to the use and required characteristic of a three-dimensional wiring board. For example, when the three-dimensional wiring board is used alone, the thickness of the thermoplastic resin film 2 may be adjusted to about 100 μm (75 μm or more and 150 μm or less). When used together, it may be adjusted to 50 μm or less.

In addition, the resin film to be prepared is not limited to the thermoplastic type, and if it is a resin film having a relatively large elongation at break, a thermosetting resin film or a thermosetting resin and a thermoplastic resin are laminated ( That is, a composite resin film having a structure in which a thermoplastic resin film and a thermosetting resin film are bonded together may be used. Here, the relatively large elongation at break is a value of at least 50%, preferably 150% or more. For breaking elongation, required properties are required depending on the three-dimensional shape to be molded, and in the case of a complicated and large step shape, a resin film material having a larger breaking elongation strength is required so that the material by three-dimensional molding can be withstood. . In addition, when the flexible portion 1c is required to bend repeatedly rather than bend several times (flex installation), it is necessary to use a film that maintains the bending strength according to the required characteristics. Similarly, when forming a wiring metal material, a coverlay or the like, the coverlay material is also required to have a flexural strength according to the required characteristics.

In this embodiment, the wiring pattern 3 is made of copper, and particularly has a laminated structure in which two metal films made of copper are laminated. The laminated structure will be described in detail when explaining the manufacturing method described later. In addition, the material of the wiring pattern 3 is not limited to copper, but various metals such as silver, gold, or nickel, or an alloy including at least one of these metals and copper, or a laminate of each metal is used. Although it may be used, it is preferable to use a metal that is relatively soft and has a high elongation at break. The materials of the two metal films constituting the material of the wiring pattern 3 may be different.

Further, as shown in FIG. 1, the wiring pattern 3 extends not only in the XY plane but also in the Z direction, and is three-dimensionally patterned. Here, the wiring pattern 3 is also formed in a bent part or a bent part by three-dimensional molding of the thermoplastic resin film 2, but the wiring pattern 3 is also broken by the bending of the flexible part 1c. There is no. The reason will be described in detail when explaining the manufacturing method described later.

Next, a method for manufacturing a three-dimensional wiring board according to an embodiment of the present invention will be described in detail with reference to FIGS. 2, 3, 5, 10, 13, 19, and 21 are cross-sectional views in the manufacturing process of the three-dimensional wiring board. 6 is an enlarged conceptual diagram of the broken line region VI in FIG. 5, FIG. 11 is an enlarged conceptual diagram of the broken line region XI in FIG. 10, and FIG. 20 is an enlarged conceptual diagram of the broken line region XX in FIG. FIG. 22 is an enlarged conceptual diagram of a broken line area XXII in FIG. Further, FIGS. 14 to 17 are schematic views showing a manufacturing process related to three-dimensional molding according to the embodiment of the present invention. 4, FIG. 7 to FIG. 9, FIG. 12, and FIG. 23 are schematic views of the metal film formation for the three-dimensional wiring board according to the embodiment of the present invention. FIG. 18 is a perspective view in the manufacturing process of the three-dimensional wiring board according to the embodiment of the present invention.

First, as shown in FIG. 2, a thermoplastic resin film 2 is prepared (preparation step). As the thermoplastic resin film 2, as described above, a known resin film such as polyimide or polyethylene terephthalate can be used. For example, the thickness is adjusted to about 100 μm (75 μm to 150 μm).

The resin film to be prepared is not limited to the thermoplastic type, and as described above, as long as the resin film has a relatively large elongation at break, it is a thermosetting resin film, or a thermosetting resin and a thermoplastic resin. A composite resin film having a structure in which resins are laminated can be used.

Next, as shown in FIG. 3, NC processing, laser processing, punching processing, or the like is performed in order to ensure conduction on the front and back surfaces (first surface 2 d and second surface 2 e) of the thermoplastic resin film 2. Through-hole 4 is formed using the opening technique. In the present embodiment, the opening diameter of the through hole 4 is about 0.3 mm. In FIG. 3, only one through hole 4 is shown, but an actual three-dimensional wiring board has a plurality of through holes 4. Moreover, the quantity of the through-hole 4 can also be suitably changed according to the circuit structure of a three-dimensional wiring board. Further, a positioning hole (for example, an opening diameter of 3 mm) for use as positioning at the time of three-dimensional molding described later is removed without forming an outer edge portion of the thermoplastic resin film 2 (that is, finally forming a three-dimensional wiring board). May be formed on a portion).

Next, on the surface of the thermoplastic resin film 2 so as to cover the first surface 2d, the second surface 2e of the thermoplastic resin film 2 and the side surface 2f of the thermoplastic resin film 2 exposed by the through holes. The first metal film 5 is formed (first metal film forming step). In this embodiment, the metal is metallized on the surface of the thermoplastic resin film 2 by electroless plating using a known molecular bonding technique.

More specifically, as a pretreatment, first, Ar plasma treatment is performed on the thermoplastic resin film 2 to remove the fragile layer on the surface of the thermoplastic resin film 2, and a functional group that is compatible with a molecular bonding agent described later is provided. It is formed on the surface of the thermoplastic resin film 2. Thereafter, the Ar resin-treated thermoplastic resin film 2 is immersed in the molecular bonding agent 6 solution (FIG. 4). Here, since the molecular bonding agent 6 has a functional group (first functional group) that reacts with the thermoplastic resin film 2, the functional group of the thermoplastic resin film 2 and the functional group of the molecular bonding agent 6 are associated with each other. As shown in FIG. 5 and FIG. 6, a state in which the molecular bonding agent 6 is bonded on the surface of the thermoplastic resin film 2 is obtained. In FIG. 5, the molecular bonding agent 6 is illustrated in a layered form for easy understanding, but actually exists in a nano-level state (the thickness of the molecular bonding agent 6 is several nm) as shown in FIG. It is very thin compared to other materials. Therefore, the molecular bonding agent 6 may be omitted from FIG. In addition, the straight line extending up and down of the molecular bonding agent 6 in FIG. 6 represents a functional group, and more specifically, a state in which the straight line extending toward the thermoplastic resin film 2 is connected to the functional group of the thermoplastic resin film 2. The straight line extending to the opposite side of the thermoplastic resin film 2 represents the functional group of the molecular bonding agent 6 that reacts with the metal of the first metal film 5.

Next, the catalyst film (Sn—Pd colloid aqueous solution) is impregnated with the thermoplastic resin film 2 subjected to the molecular bonding treatment (FIG. 7). Here, the Sn—Pd colloid is electrically adsorbed on the surface of the thermoplastic resin film 2. Thereafter, when the accelerator liquid is impregnated with the thermoplastic resin film 2 having Sn—Pd colloid supported on the surface, Sn covering the periphery of Pd is removed, and Pd ions are changed to metal Pd (FIG. 8). That is, a catalyst treatment (for example, Pd) is carried on the thermoplastic resin film 2 by performing a catalyst treatment. As the accelerator liquid, sulfuric acid (concentration: 10%) containing oxalic acid (about 0.1%) can be used. Thereafter, the thermoplastic resin film 2 carrying Pd as a catalyst is immersed in an electroless plating tank for 5 minutes, for example. By the immersion, for example, copper is precipitated using Pd as a catalyst, and the precipitated copper is bonded to the molecular bonding agent 6 (FIG. 9). Here, since the molecular bonding agent 6 also includes a functional group (second functional group) that reacts with the metal of the first metal film 5, the end of the molecular bonding agent 6 that is bonded to the thermoplastic resin film 2. A metal is chemically bonded to the end portion (second functional group) located on the opposite side of the substrate using a catalyst. Subsequently, the thermoplastic resin film 2 is heated at 150 ° C. for 10 minutes to terminate the chemical bond between the molecular bonding agent 6 and the metal, and as shown in FIG. 10, the surface of the thermoplastic resin film 2 The formation of the first metal film 5 (that is, molecular bonding between the thermoplastic resin film 2 and the first metal film 5) is completed so as to cover the surface.

Here, the above-described molecular bonding agent 6 is a chemical for chemically bonding a resin and a metal or the like, and a functional group that bonds to the resin and a functional group that bonds to the metal exist in one molecular structure. To do. The molecular bonding technique is a technique for chemically bonding a resin and a metal or the like using the molecular bonding agent 6 having such a structure. Further, these molecular bonding agents and molecular bonding techniques are described in more detail in Japanese Patent No. 04936344, Japanese Patent No. 05729852, and Japanese Patent No. 05083926.

In this embodiment, copper is used as the metal of the first metal film 5, and as shown in FIG. 11, the electroless plating is generated in the form of particles, and the first metal film 5 is formed in a porous shape by the copper particles 5a. Is done. Here, the term “porous” means that the first metal film 5 does not have a film thickness that is completely formed on the film, but the entire film is electrically connected when at least a part of the particles are not all in contact with each other. (It is not always necessary to conduct electricity, and even if the distance between particles is separated by three-dimensional molding, it may be conducted by a second metal film described later). In other words, in the present embodiment, the first metal film 5 having a film thickness capable of transmitting light is formed by depositing copper in a particle form in the range of 0.02 μm to 0.20 μm. . The reason for adjusting the state (that is, the film thickness) of the first metal film 5 is that if the first metal film 5 is formed in a complete film shape that does not transmit light, the three-dimensional molding described later is performed. This is because even if a crack is generated in the first metal film 5, it is difficult to repair the crack even by a second metal film described later. More specifically, if the first metal film 5 is thinner than 0.02 μm, the contact between the resin and copper is reduced, the adhesion is lowered, and the distance between the particles after being stretched is too far apart, and the second metal film described later. It becomes difficult to repair continuity in Further, when the film is stretched in a state of transmitting light, the distance between the particles is only large, so the crack is small. However, when the film is stretched in a complete film shape that does not transmit light, the metal film exceeding the limit (first metal film 5 ) Is cracked and becomes a wide crack. In FIG. 11, only one particle 5 a is shown in the film thickness direction of the first metal film 5, but if the first metal film 5 is porous, a plurality of particles 5 a are present. May be laminated in the film thickness direction.

The process of forming the first metal film 5 in a porous shape will be described in detail below. When copper is further precipitated from the state where the copper shown in FIG. 9 has started to precipitate, the newly precipitated copper is either the molecular bonding agent 6 or the copper that has already been precipitated and reacts with the molecular bonding agent 6. Make metal bonds. At this time, since the activity of Pd, which is a catalyst, is higher than the autocatalytic action of copper, the production of copper proceeds in the plane direction (that is, the direction spreading on the surface of the thermoplastic resin film 2). It will also begin to proceed in the thickness direction (that is, the thickness direction of the first metal film 5). And when the autocatalytic action of copper starts, copper will precipitate sequentially and the metal bond of copper will advance, the growth of copper will advance by a thickness direction, and a film thickness will increase. In this state, as shown in FIG. 12, although there is a void portion where copper does not exist and there is a portion where electrical conduction is not partially obtained, the formed metal film as a whole is electrically Since there is a connection path, electrical continuity is obtained. As described above, such a state is a porous shape in the present embodiment. In such a porous first metal film 5, even if the elongation at break of copper is exceeded, a large crack is not generated, and the distance between the copper molecules is partially expanded slightly. .

In this embodiment, since the thermoplastic resin film 2 and the first metal film 5 are chemically bonded via the molecular bonding agent 6, the interface between the thermoplastic resin film 2 and the first metal film 5 is defined. Both members can be firmly joined while being smooth. Thereby, it is not necessary to form unevenness on the surface of the thermoplastic resin film 2, and the manufacturing process can be facilitated, the manufacturing cost can be reduced, and the wiring circuit to be formed can have high definition. The molecular bonding agent to be used is not limited to one type. For example, the molecular bonding agent 6 is mixed with another molecular bonding agent having a functional group that reacts with the molecular bonding agent 6 and the first metal film 5. The compound formed may be used, and may be appropriately changed including other process conditions depending on the materials of the thermoplastic resin film 2 and the first metal film 5.

In addition, the material of the first metal film 5 is not limited to copper, for example, various metals such as silver, gold, or nickel, or alloys or metals containing at least one of these metals and copper. Although a laminated material may be used, it is preferable to use a metal that is relatively soft and has a high elongation at break. Here, since the film thickness for realizing the state of transmitting light and conducting is different depending on the metal to be used, the first metal film 5 is formed in a porous shape when another metal is used. Therefore, the film thickness is adjusted as appropriate so that the above can be realized.

Furthermore, the method for forming the first metal film 5 is not limited to the method using the molecular bonding technique described above, and if the first metal film 5 can be formed in a porous shape, for example, sputtering, vapor deposition, Alternatively, a film forming technique such as wet plating other than the method using molecular bonding may be used. And about formation of the 1st metal film 5, you may select the optimal film-forming technique according to the metal material used.

In the present embodiment, the first metal film is formed so as to cover the first surface 2d, the second surface 2e of the thermoplastic resin film 2 and the side surface 2f of the thermoplastic resin film 2 exposed by the through holes. The first metal film 5 is formed only on either the first surface 2d or the second surface 2e of the thermoplastic resin film 2 in accordance with the required structure and characteristics of the three-dimensional wiring board. It may be formed. That is, the three-dimensional wiring board of the present invention includes not only those having wiring patterns formed on both sides but also those having wiring patterns 3 formed only on one side.

Next, as shown in FIG. 13, the first metal film 5 is subjected to patterning processing by photolithography to form a desired wiring pattern (pattern forming step). Specifically, a resist film is thermocompression bonded to the surface of the thermoplastic resin film 2 on which the first metal film 5 is formed, and exposure and development are performed using a mask film on which a predetermined pattern is printed. Subsequently, the first resist film 5 is etched using the developed resist film as an etching mask to form a desired wiring pattern. Thereafter, the resist film is peeled and removed. Here, it is preferable to adjust the shape of the wiring pattern (wiring width, wiring length, wiring spacing, etc.) in consideration of the elongation and deformation of the first metal film 5 due to three-dimensional molding described later.

Thus, since the first metal film 5 is patterned by photolithography, it is possible to realize a higher definition pattern than patterning using an inkjet printing technique or a gravure offset printing technique. That is, the first metal film 5 has higher resolution (that is, excellent linearity and high-definition wiring formation) than a wiring pattern patterned using an ink jet printing technique or a gravure offset printing technique. )Become.

Next, the thermoplastic resin film 2 on which the first metal film 5 is formed is subjected to heat treatment and pressure treatment to perform three-dimensional molding (three-dimensional molding step). As a specific three-dimensional molding process, first, the thermoplastic resin film 2 is positioned with respect to the molding die 11 using the positioning holes described above. This is for matching the molding position and the wiring pattern position. That is, as shown in FIG. 14, the thermoplastic resin film 2 is disposed between the upper mold 12 and the lower mold 13 of the mold 11. Here, the upper mold 12 forms the first three-dimensional molded part 12a to form the rigid part 2a on the thermoplastic resin film 2, the second three-dimensional molded part 12b to form the rigid part 2b, and the flexible part 2c. Therefore, the flat part 12c is provided. Similarly, the lower mold 13 is also formed with the first three-dimensional molded portion 13a for forming the rigid portion 2a on the thermoplastic resin film 2, the second three-dimensional molded portion 13b and the flexible portion 2c for forming the rigid portion 2b. Therefore, a flat portion 13c is provided. That is, the first three-dimensional molding part 12a of the upper mold 12 and the first three-dimensional molding part 13a of the lower mold 13 are opposed to each other, and the second three-dimensional molding part 12b of the upper mold 12 and the second three-dimensional molding of the lower mold 13 are arranged. The molding part 13b faces, the flat part 12c of the upper mold 12 and the flat part 13c of the lower mold 13 face each other, and the thermoplastic resin film 2 is sandwiched therebetween.

Subsequently, as shown in FIG. 15, the upper mold 12 is heated by the upper heating device 14, and the lower mold 13 is heated by the lower heating device 15. In this example, since a polyimide film is used as the thermoplastic resin film 2, the heating temperature is adjusted within a range of 270 ° C. to 350 ° C. (eg, 300 ° C.) higher than the glass transition temperature of the material. The heating temperature is appropriately adjusted according to the material of the thermoplastic resin film 2. Here, the heating temperature is required to be equal to or higher than the glass transition temperature and equal to or lower than the heat resistant temperature of the thermoplastic resin film 2, and is preferably set to the lowest possible temperature within the range. This is to reduce a decrease in adhesion due to heating of the first metal film 5 and the thermoplastic resin film 2 formed on the thermoplastic resin film 2.

While performing the heat treatment, the upper die 12 and the lower die 13 are brought closer to each other, and the thermoplastic resin film 2 is pressed from above and below with a desired pressure (for example, 10 MPa) (FIG. 16). The desired pressure is appropriately adjusted in consideration of the material of the thermoplastic resin film 2 and the point that the desired three-dimensional molding becomes difficult if the pressure is too weak. Then, after the press process is completed, the thermoplastic resin film 2 is taken out from the mold 11 (FIG. 17), and the three-dimensional molding of the thermoplastic resin film 2 is completed. In other words, the formation of the three-dimensional wiring board substrate 16 is completed. In FIGS. 14 to 17, the first metal film 5 is not shown. In addition, although depending on the required three-dimensional shape, the actual three-dimensional wiring board 1 is actually formed with a plurality of projections and depressions. The two-dimensional molded part 12b and the first three-dimensional molded part 13a and the second three-dimensional molded part 13b of the lower mold 13 have a plurality of irregularities, and the plurality of irregularities between the upper mold 12 and the lower mold 13 are A structure that fits each other may be adopted.

In the present embodiment, one mold 11 is used and the thermoplastic resin film 2 is three-dimensionally molded by one heat treatment and pressure treatment, which corresponds to each of the

rigid portions

1a and 1b. Three-dimensional molding may be performed by using an independent mold and performing heat treatment and pressure treatment once or twice. When using an independent mold, it is necessary to set a part that has been three-dimensionally molded so that it is not sandwiched again by another mold, and the part that becomes the flexible part 1c is also a mold. It is necessary to prevent deformation due to pinching caused by.

As can be seen from FIG. 18, the removed thermoplastic resin film 2 is three-dimensionally molded, and the first metal film 5 is formed on both surfaces thereof. Further, as shown in FIG. 18, the first metal film 5 has already been patterned, and the first metal film 5 functions as a base of the wiring pattern 3, so that it has the same wiring shape as the wiring pattern 3. Yes.

Further, as shown in FIG. 19, the thermoplastic resin film 2 (that is, the substrate 16 for a three-dimensional wiring board) that has undergone the three-dimensional molding is likely to have a crack 17 in the bent portion 2g that is bent by the three-dimensional molding. It has become. Here, as shown in FIG. 20, the crack 17 is a gap formed by an increase in the inter-particle distance of the copper particles 5a constituting the first metal film 5, and is a complete metal film shape that does not transmit light. The structure is different from that of a crack generated by stretching the metal film. In addition, a crack may not generate | occur | produce depending on the film-forming state of the 1st metal film 5, and the three-dimensional shape by three-dimensional shaping | molding. In addition, as shown in FIG. 19, the crack 17 is caused by the thermoplastic resin film 2 being stretched, whereas the first metal film 5 has an increased interparticle distance, but the first metal film 5 is Since it is formed in a porous shape, the depth of the crack 17 itself is equivalent to the size of the particle 5a and becomes very small, and further compared with the case where the first metal film 5 is formed in a complete film shape. Thus, the width of the crack 17 is also reduced. That is, the substrate 16 for a three-dimensional wiring board according to the present embodiment is in a state in which the crack 17 can be repaired more easily than in the case where the first metal film 5 is formed in a complete film shape. It has become. In other words, the crack 17 (gap between the particles) is small when stretched in a state where light is transmitted because the distance between the particles is only large, but the limit is exceeded when the film is stretched in a complete film shape that does not transmit light. The metal film is cracked and a wide crack is generated.

Further, as a method of reducing the occurrence of the crack 17 in the bent portion 2g, the above-described three-dimensional molding may be performed in a state where the thermoplastic resin film 2 is sandwiched between two protective films. Thereby, the shape of the corner | angular part 2h in the bending part 2g can be made slightly smooth, and generation | occurrence | production of the crack 17 can be suppressed. Here, the protective film is preferably formed of the same material as the thermoplastic resin film 2. Further, as a method of reducing the occurrence of the crack 17 in the bent portion 2g, the shape of the corner portion 2h in the bent portion 2g is curved, or the angle is made smaller than 90 degrees (for example, 75 to 85 degrees). In addition, the mold 11 may be designed.

In this embodiment, the thermoplastic resin film 2 is pressed from above and below using the upper mold 12 and the lower mold 13, but the thickness uniformity of the thermoplastic resin film 2 after the heat press is performed. May be used, other press working methods such as a vacuum press or a pneumatic press may be used.

Next, the second metal film 21 is formed so as to cover the surface of the first metal film 5 of the substrate 16 for the three-dimensional wiring board (second metal film forming step: FIG. 21). In this embodiment, a metal is additionally deposited on the surface of the first metal film 5 by general electroless plating.

As a specific second metal film forming step, first, the three-dimensional wiring substrate base material 16 is desired in order to remove the oxide layer formed on the surface of the three-dimensional wiring substrate base material 16 by heating in the molding step. Soak in a cleaning solution (for example, acid degreasing solution, sulfuric acid solution). Subsequently, a catalyst treatment is performed to cause the first metal film 5 of the substrate 16 for a three-dimensional wiring board to react with a catalyst (for example, a Pd catalyst) of the type that replaces the first metal film 5, and then the substrate for the three-dimensional wiring board The material 16 is immersed in an electroless plating solution. Then, metal is selectively deposited only around the first metal film 5 where the catalyst is present on the surface, and the metal that does not become a wiring circuit (that is, the exposed region of the thermoplastic resin film 2) is metal. Is not deposited, and additional patterning of the second metal film 21 becomes unnecessary.

In this embodiment, copper is used as the metal of the second metal film 21, and as can be seen from FIGS. 21 and 22, a plurality of copper particles 21 a are deposited on the particles 5 a of the first metal film 5. . Here, the second metal film 21 is formed in a complete film shape without being formed in a porous shape. In particular, in this example, the second metal film 21 having a film thickness of 5 μm or more could be formed by immersion for 1 hour. In the present embodiment, the particles 21a constituting the second metal film 21 grow around the particles 5a constituting the first metal film 5, and the thickness direction and the thickness of the second metal film 21 are related to each other. It grows to the same extent with respect to the direction orthogonal to the direction (planar direction of the second metal film 21). Thereby, the 2nd metal film 21 can be formed so that the crack 17 of the 1st metal film 5 which arose by three-dimensional shaping | molding may be repaired. That is, it is a wiring circuit (a conductor layer made up of the first metal film 5 and the second metal film 21) that can restore the conduction failure due to the crack 17 and realize reliable conduction by forming the second metal film 21. The wiring pattern 3 can be formed. Here, the repair of the crack 17 by the second metal film 21 can repair the width of the crack 17 about twice the film thickness of the second metal film 21, and therefore the film thickness of the second metal film 21 is assumed. It may be adjusted to ½ times or more of the maximum width of the crack 17, more preferably adjusted to a film thickness comparable to the width of the crack 17. Further, the second metal film 21 is generated on the side surface 2f of the through hole 4 in the same manner as the surface layer, and it is possible to repair the conduction even if there is a front / back conduction failure due to the through hole 4.

Furthermore, in this embodiment, the layer thickness (wiring pattern thickness) of the conductor layer necessary for the wiring circuit is insufficient with the film thickness of the first metal film 5, but by forming the second metal film 21. The required layer thickness of the conductor layer can be ensured.

In the present embodiment, the second metal film 21 is formed by electroless plating. However, if the second metal film 21 can be finally formed only on the surface of the first metal film 5, another film is formed. Techniques (for example, electrolytic plating, application of conductive ink, etc.) may be used. However, when the second metal film 21 is formed by electroless plating as in this embodiment, it can be formed even if the independent wiring, that is, the wiring circuit is electrically separated from the outer peripheral portion of the molded body. However, when the second metal film 21 is formed by electrolytic plating, it is necessary that all the wirings are electrically connected to the outer peripheral portion of the molded body, which is taken into consideration at the time of design including the installation of the feeder line. It will be necessary. Further, in this case, when a non-conductive portion is generated by the three-dimensional molding, the second metal film 21 cannot be formed because electricity does not flow beyond the non-conductive portion.

The material of the second metal film 21 is not limited to copper, and other metals such as nickel or nickel chrome, nickel copper, gold, or silver or alloys containing these may be used for the three-dimensional wiring board. The material can be appropriately adjusted according to required characteristics and reliability.

After passing through the manufacturing process described above, the surface of the second metal film 21 is subjected to a rust preventive agent treatment, and the three-dimensional wiring board constituted by the thermoplastic resin film 2, the first metal film 5, and the second metal film 21. 1 is completed. Note that a protective film made of a solder resist may be further formed on a necessary portion of the surface of the three-dimensional wiring board 1. In this case, a method such as applying a solder resist to a necessary portion by an inject method using an ink jet apparatus can be considered. Further, instead of applying the solder resist, a protective coating film (coverlay) made of resin may be attached.

As can be seen from FIGS. 20 to 22, in the three-dimensional wiring board 1 according to this example, cracks generated in the first metal film 5 formed in a porous shape on the surface of the thermoplastic resin film 2 are caused by the first metal film. It is reliably repaired by the second metal film 21 formed with a film thickness thicker than 5, and has excellent reliability in which disconnection of the wiring circuit is prevented. In addition, a fine wiring pattern (for example, L / S = 30/30 μm) can be realized more easily than the MID substrate by the manufacturing method described above, and miniaturization and cost reduction are also realized. Yes.

As shown in FIG. 1, the finally formed three-dimensional wiring board 1 has different dimensions (that is, heights) in the Z direction at the respective positions in the X direction and the Y direction. Unevenness is formed.

In the above-described embodiment, one three-dimensional wiring board 1 is manufactured through the above manufacturing process. However, a plurality of three-dimensional wiring boards 1 may be formed simultaneously by one manufacturing process. . That is, a plurality of (for example, four) three-dimensional wiring boards 1 can be manufactured simultaneously from one thermoplastic resin film (worksheet). In this case, the

rigid parts

1a and 1b and the flexible part 1c may be punched (die-cut) by external processing so as to be integrated. In addition, the said external shape processing may be naturally performed also when manufacturing one three-dimensional wiring board on the sheet | seat of 1 sheet.

The three-dimensional wiring board 1 according to the present embodiment uses a thermoplastic resin film 2 as a base material, but has a structure in which two

rigid portions

1a and 1b are connected by a single flexible portion 1c. It can be used as a substitute for a flexible substrate. That is, it is possible to easily realize a favorable arrangement of the three-dimensional wiring board corresponding to a device housing having a narrow space or a three-dimensional shape. Further, in the three-dimensional wiring board 1 according to the present embodiment, another connecting component for connecting the

rigid portions

1a and 1b is unnecessary, and the cost can be reduced by reducing the number of components. In particular, in the manufacturing method of the three-dimensional wiring board 1 according to the present embodiment, since the two

rigid parts

1a and 1b are three-dimensionally molded simultaneously and integrally, the manufacturing method is compared with the conventional manufacturing method of rigid flexible boards. Since the process becomes simpler, costs can be reduced even when compared with conventional products.

Moreover, in the manufacturing method of the three-dimensional wiring board according to the present embodiment, the first metal film 5 is formed in a porous shape, and therefore cracks that cannot be repaired are formed in the first metal film 5 in the subsequent three-dimensional forming process. Generation | occurrence | production can be prevented and the wiring pattern 3 more robust and excellent in reliability can be formed. Since the crack can be repaired by the second metal film, the wiring pattern 3 can be formed in a stronger and more reliable state, and even if the three-dimensional wiring board 1 is bent, the wiring pattern 3 can be formed. The pattern 3 is prevented from being cracked.

In the three-dimensional wiring board 1 manufactured by the manufacturing method described above, in order to maintain a three-dimensional shape, the thickness of the thermoplastic resin film 2 serving as a base material is 75 μm or more. There is a possibility that deterioration in the flexible part 1c (breakage of the thermoplastic resin film 2 or the like) may occur. For this reason, the three-dimensional wiring board 1 manufactured by the above-described manufacturing method is not suitable for repeated bending, and excessive bending is caused after bending when the three-dimensional wiring board 1 is incorporated in the housing. The basic usage is the so-called flex installation. However, if the rigidity can be ensured by covering the front and back surfaces of the three-dimensional wiring board 1 with another resin or the like, the flexible portion 1c can be made thin (75 μm or less), and therefore the thermoplastic resin film 2 is repeatedly bent. And can be used for repeated bending.

In addition, the three-dimensional wiring board 1 according to the present embodiment has a structure in which the two

rigid portions

1a and 1b are connected by one flexible portion 1c. However, as shown in FIG. It is good also as a structure which consists of the flexible part 101b connected to the said rigid part 101a. Here, in the three-dimensional wiring board 101 shown in FIG. 24, the flexible part 101b is provided with an external connection terminal 107 on the other end opposite to one end connected to the rigid part 101a. That is, the three-dimensional wiring board 101 shown in FIG. 24 has a flying tail structure. When manufacturing the three-dimensional wiring board 101 having such a flying tail structure, in the pattern forming process described above, the external connection terminal 107 is formed at one end of the region to be the flexible portion 2c in the subsequent three-dimensional molding process. In the subsequent three-dimensional molding process, the three-dimensional molding is not performed on the portion where the external connection terminal 107 is formed.

Furthermore, the quantity of the rigid part 1a and the flexible part 1c is not limited to the quantity of the above-described embodiment, but three or more rigid parts may be formed, and each rigid part may be connected by the flexible part. That is, for a part of the flexible portion, the flexibility may extend in a desired direction from two end portions facing each other or from two adjacent end portions. On the other hand, it is good also as a structure where the some flexible part extended from one rigid part. That is, a flying tail structure in which a flexible portion extends from each end portion of one rigid portion may be formed. Or it is good also as a structure where the other flexible part (flying tail part) as a flying tail is mixed from each rigid part and the flexible part which connects these, and a rigid part.

In FIG. 1, the

rigid portions

1a and 1b protrude in the + Z direction (that is, provided with a convex shape on the upper side of the drawing), but either one of the

rigid portions

1a and 1b protrudes in the −Z direction. (In other words, it may have a shape that is convex (in short, concave) on the lower side of the drawing).

In addition, a conductor layer that is not patterned or a mesh-like conductor layer is formed on one side of the thermoplastic resin film 2 and is grounded to function as a GND layer. A conductor layer that is located on the opposite side of the unpatterned conductor layer A single characteristic impedance control pattern or a differential impedance control pattern may be formed. That is, in the conductor layer located on the opposite side of the unpatterned conductor layer, a wiring width that provides the required impedance, a pair of pattern width and gap width, and wiring thickness in the case of differential impedance wiring, etc. It is possible to form a wiring pattern considering the above. With such a structure, impedance control can be achieved in the three-dimensional wiring board 1. In particular, in this embodiment, a conductor layer or a mesh-like ground conductor layer that is not subjected to the patterning can be formed on one surface of the flexible portion 1c, so that more excellent impedance control is possible. In addition, the impedance value is the material thickness and dielectric constant of the thermoplastic resin film 2 or the like, the structure of the conductor layer or mesh-like conductor layer not subjected to the patterning, and on both sides of the pair of wirings in the case of differential impedance wiring. Since it is affected by the distance from the ground wiring to be provided, it is important to design by simulation in consideration of these influences or to confirm by an actual sample.

<Embodiment of the present invention>
A three-dimensional wiring board according to a first embodiment of the present invention includes a resin film having a three-dimensional shape and having a break elongation of 50% or more, and a wiring pattern having a desired pattern formed on the surface of the resin film. And the resin film includes a rigid portion having the three-dimensional shape, and a flexible portion extending in a desired direction from an end portion of the rigid portion and having flexibility.

In the first embodiment, although a resin film is used as the base material, it has a structure in which the rigid part is connected to the flexible part. Therefore, by bending the flexible part, it has a narrow space and a three-dimensional shape. It is possible to easily realize a favorable arrangement of the three-dimensional wiring board corresponding to the device casing or the like. Moreover, in the three-dimensional wiring board according to the first embodiment, another connection component for electrically connecting to the wiring pattern in the rigid portion is not necessary, and the cost can be reduced by reducing the number of components. In particular, since the rigid portion and the flexible portion are three-dimensionally molded simultaneously and integrally, the manufacturing process can be simplified and reduced, and the manufacturing cost can be reduced.

The three-dimensional wiring board according to the second embodiment of the present invention is that the wiring pattern is formed on both surfaces of the resin film in the first embodiment described above. As a result, the density of the three-dimensional wiring board can be increased.

The three-dimensional wiring board according to a third embodiment of the present invention is the first or second embodiment described above, wherein the wiring pattern has a first metal film having a porous structure in which metal is deposited in the form of particles, and It consists of the 2nd metal film laminated | stacked on the said 1st metal film. As a result, even if a crack occurs in the first metal film, the crack can be repaired by additional film formation, so that a final conduction failure is prevented.

In the three-dimensional wiring board according to the fourth embodiment of the present invention, in any one of the first to third embodiments described above, the resin film includes a plurality of rigid portions, and each of the plurality of rigid portions is the flexible. It is connected to the other rigid part via the part. As a result, it is possible to provide a three-dimensional wiring board manufactured at a lower cost that can replace the known flex-rigid board.

In the three-dimensional wiring board according to the fifth embodiment of the present invention, in any one of the first to third embodiments described above, the flexible portion is externally connected to the other end opposite to the one end connected to the rigid portion. It is to provide a terminal for use. As a result, it is possible to provide a three-dimensional wiring board manufactured at a lower cost as a substitute board for the known flying tail.

The manufacturing method of the three-dimensional wiring board which concerns on the 6th embodiment of this invention is a preparatory process which prepares the resin film provided with 50% or more elongation at break, and forms the 1st metal film on the surface of the said resin film. A metal film forming process, a pattern forming process for patterning the first metal film by photolithography to form a desired pattern, and a three-dimensional molding process for performing three-dimensional molding by applying heat and pressure to the resin film. A wiring pattern forming step of forming a wiring pattern by laminating a second metal film on the patterned first metal film, and the three-dimensional molding step includes a rigid portion having a three-dimensional shape, and A flexible portion extending in a desired direction from the end of the rigid portion and having flexibility is formed on the resin film.

In the sixth embodiment, although a resin film is used as the base material, an apparatus housing having a narrow space or a three-dimensional shape is formed by bending the flexible part in order to form a structure in which the rigid part is connected to the flexible part. It is possible to provide a three-dimensional wiring board that can correspond to a body or the like. A separate connecting component for electrically connecting to the wiring pattern in the rigid portion and its mounting process are not required, and the cost can be reduced by reducing the number of components and the mounting process. In particular, since the rigid portion and the flexible portion are three-dimensionally molded simultaneously and integrally, the manufacturing process can be simplified and reduced, and the manufacturing cost can be reduced.

The manufacturing method of the three-dimensional wiring board which concerns on the 7th embodiment of this invention is that the said 1st metal film formation process forms the said 1st metal film on both surfaces of the said resin film in the 6th embodiment mentioned above. is there. Wiring patterns can be formed on both surfaces of the three-dimensional wiring board, and the density of the three-dimensional wiring board can be increased.

The manufacturing method of the three-dimensional wiring board which concerns on the 8th embodiment of this invention WHEREIN: In the 6th or 7th embodiment mentioned above, in the said 1st metal film formation process, metal is deposited to particle shape and a film thickness is adjusted. Thus, the first metal film is formed in a porous shape. Thereby, it is possible to prevent the first metal film from generating a crack that cannot be repaired even in the subsequent three-dimensional formation process.

A manufacturing method of a three-dimensional wiring board according to a ninth embodiment of the present invention is the method according to any one of the sixth to eighth embodiments described above, wherein in the three-dimensional molding step, a plurality of the rigid portions are formed and a plurality of the rigids are formed. It is solid-molding so that a part may be connected by the flexible part. As a result, it is possible to provide a three-dimensional wiring board manufactured at a lower cost that can replace the known flex-rigid board.

The manufacturing method of the three-dimensional wiring board which concerns on the 9th embodiment of this invention is one end of the area | region used as the said flexible part in the said three-dimensional shaping | molding process in the said pattern formation process in any of the 6th thru | or 8th embodiment mentioned above. In the three-dimensional molding step, the three-dimensional molding is not performed on the portion where the external connection terminal is formed. As a result, it is possible to provide a three-dimensional wiring board manufactured at a lower cost as a substitute board for the known flying tail.

The manufacturing method of the three-dimensional wiring board according to the eleventh embodiment of the present invention is the method according to any one of the sixth to tenth embodiments described above, wherein in the three-dimensional molding step, the rigid part and the flexible part are formed by one mold. Is to form. Thereby, the die cost can be reduced, and the manufacturing cost of the three-dimensional molded substrate can be reduced.

The manufacturing method of the three-dimensional wiring board according to the twelfth embodiment of the present invention is the method according to any one of the ninth embodiments described above, wherein in the three-dimensional molding step, the three-dimensional wiring board is three-dimensional with independent molds that form the plurality of rigid portions. It is to mold. Thereby, highly accurate three-dimensional shaping | molding is realizable.

DESCRIPTION OF SYMBOLS 1 Three-

dimensional wiring board

1a, 1b Ridged part 1c Flexible part 2

Thermoplastic resin film

2a, 2b Ridged part 2c Flexible part 2d 1st surface 2e 2nd surface 2f Side surface 2g Bending part 2h Corner | angular part 3 Wiring pattern 4 Through-hole 5 First metal film 5a Particle 6 Molecular bonding agent 11 Mold 12 Upper mold 12a First three-dimensional molding part 12b Second three-dimensional molding part 12c Flat part 13 Lower mold 13a First three-dimensional molding part 13b Second three-dimensional molding part 13c Flat Part 14 Upper heating device 15 Lower heating device 16 Substrate for three-dimensional wiring board 17 Crack 21 Second metal film 21a Particle

Claims

A resin film having a three-dimensional shape and having an elongation at break of 50% or more;
A wiring pattern formed on the surface of the resin film and having a desired pattern;
The said resin film is a three-dimensional wiring board containing the rigid part provided with the said three-dimensional shape, and the flexible part extended in a desired direction from the edge part of the said rigid part, and provided with a softness | flexibility.
The wiring board according to claim 1, wherein the wiring pattern is formed on both surfaces of the resin film.
The said wiring pattern consists of a 1st metal film provided with the porous structure formed by depositing a metal in the shape of a particle, and the 2nd metal film laminated | stacked on the said 1st metal film. Three-dimensional wiring board.
The resin film includes a plurality of the rigid portions,
4. The three-dimensional wiring board according to claim 1, wherein each of the plurality of rigid portions is connected to another rigid portion via the flexible portion. 5.
The three-dimensional wiring board according to any one of claims 1 to 3, wherein the flexible portion includes an external connection terminal on the other end opposite to one end connected to the rigid portion.
A preparation step of preparing a resin film having an elongation at break of 50% or more;
A first metal film forming step of forming a first metal film on the surface of the resin film;
Patterning the first metal film by photolithography to form a desired pattern; and
A three-dimensional molding process in which three-dimensional molding is performed by applying heat and pressure to the resin film;
A wiring pattern forming step of forming a wiring pattern by laminating a second metal film on the patterned first metal film,
The three-dimensional molding step is a method for manufacturing a three-dimensional wiring board in which a rigid portion having a three-dimensional shape and a flexible portion extending in a desired direction from an end portion of the rigid portion and having flexibility are formed on the resin film.
The manufacturing method of a three-dimensional wiring board according to claim 6, wherein in the first metal film forming step, the first metal film is formed on both surfaces of the resin film.
The method of manufacturing a three-dimensional wiring board according to claim 6 or 7, wherein, in the first metal film forming step, the first metal film is formed in a porous shape by depositing metal in a particle shape and adjusting a film thickness. .
The three-dimensional wiring board according to any one of claims 6 to 8, wherein, in the three-dimensional molding step, a plurality of the rigid portions are formed and a plurality of the rigid portions are three-dimensionally molded so as to be connected by the flexible portion. Production method.
In the pattern forming step, an external connection terminal is formed at one end of the region to be the flexible portion in the three-dimensional molding step,
The method for manufacturing a three-dimensional wiring board according to any one of claims 6 to 8, wherein in the three-dimensional molding step, the three-dimensional molding is not performed on a portion where the external connection terminal is formed.
The method for manufacturing a three-dimensional wiring board according to any one of claims 6 to 10, wherein in the three-dimensional molding step, the rigid portion and the flexible portion are formed by a single mold.
The method for manufacturing a three-dimensional wiring board according to claim 9, wherein, in the three-dimensional molding step, three-dimensional molding is performed by an independent mold that forms each of the plurality of rigid portions.