JP3101047U - Multilayer flexible printed wiring board - Google Patents

Abstract

A film adhesive is difficult to handle, and it is not easy to manufacture a multilayer flexible printed wiring board using such an adhesive. Therefore, there is a need for a multilayer flexible printed wiring board that can be easily manufactured.
A multi-layer flexible printed wiring board formed by laminating a plurality of flexible printed wiring boards, wherein the flexible printed wiring board has adhesive layers formed on both sides of a base film layer made of a polyimide film or a polyester film. A multilayer flexible printed wiring board laminated via a joining member.
[Selection diagram] Fig. 1

Description

  The present invention relates to a multilayer flexible printed wiring board and a method of manufacturing the same, and more particularly to a multilayer flexible printed wiring board that is easy to manufacture and a method of manufacturing the same.

  In recent years, the development of the electronics field has been remarkable, and in particular, electronic devices for communication and consumer use have been reduced in size, weight, and density, and demands for these performances have been increasingly sophisticated. In response to such demands, flexible printed wiring boards are flexible and have the property of withstanding repeated bending, so that they can be mounted three-dimensionally and with high density in a narrow space, and can be connected to electronic devices. Its use is expanding as a composite part provided with a cable or a connector function.

  In this flexible printed wiring board, a wiring pattern made of a conductive material is formed in close contact with the surface of an insulating and flexible base film. Further, except for a part to be soldered or a contact part, the surface is insulated and covered with a flexible resin film called a coverlay.

  Electroconductive copper foil or rolled copper foil having a thickness of 18 μm, 35 μm, or 70 μm is mainly used as a conductive material for forming a wiring pattern, and such a copper foil is adhered to a base film to form a flexible copper-clad board. After the manufacture of a flexible printed wiring board, unnecessary copper foil other than the wiring pattern is dissolved and removed from the flexible copper-clad board with a chemical.

And a multilayer flexible printed wiring board is obtained by laminating a plurality of flexible printed wiring boards as described above via a film-like adhesive called a bonding sheet. A film-like adhesive used for manufacturing such a multilayer flexible printed wiring board is, for example, a material obtained by bonding a release material having one surface coated with an adhesive and another release material (for example, see Patent Document 1). 1).
JP 2003-023248

  However, the film adhesive as described above is difficult to handle, and it has not been easy to bond flexible printed wiring boards together to form a multilayer flexible printed wiring board using such an adhesive.

  The present invention has been made to solve the above-described problems, and has as its object to provide a multilayer flexible printed wiring board which is easy to manufacture and a method for manufacturing the same.

  The multilayer flexible printed wiring board of the present invention is a multilayer flexible printed wiring board obtained by laminating a plurality of flexible printed wiring boards, and the flexible printed wiring board has an adhesive layer on both sides of a base film layer made of a resin film. It is characterized by being laminated via the formed joining member.

  The method for manufacturing a multilayer flexible printed wiring board according to the present invention is a method for manufacturing a multilayer flexible printed wiring board formed by laminating a plurality of flexible printed wiring boards, wherein the flexible printed wiring board and a base film comprising a resin film are provided. A step of alternately superimposing a joining member having an adhesive layer formed on both surfaces of the layer, and a step of pressing and heating the flexible printed wiring board and the joining member which are alternately superimposed to integrate them. It is characterized by having.

  According to the present invention, by using a bonding member having an adhesive layer formed on both sides of a base film layer made of a resin film as a bonding member used for bonding a plurality of flexible printed wiring boards, handling of the bonding member is facilitated. Thus, the manufacture of the multilayer flexible printed wiring board can be facilitated.

  Hereinafter, the multilayer flexible printed wiring board of the present invention will be described with reference to the drawings.

  FIG. 1 is a sectional view showing an example of an embodiment of the multilayer flexible printed wiring board 1 of the present invention. The multilayer flexible printed wiring board 1 of the present embodiment is formed by joining at least two flexible printed wiring boards 2 via a joining member 3.

  Each flexible printed wiring board 2 is manufactured by a conventional method for manufacturing a flexible printed wiring board. For example, electrolytic copper foil or rolled copper is provided on both sides of a base film layer 4 having insulation and flexibility. A conductive layer 5 formed by forming a foil into a desired wiring pattern is formed, and an insulating coating layer 6 made of a flexible resin film is formed on the base film layer 4 and the conductive layer 5.

  The base film layer 4 of the flexible printed wiring board 2 is made of a resin film. Examples of such a resin film include polyimide resin, acrylic resin, polyether nitrile resin, polyether sulfone resin, polyester resin, and polyethylene naphthalate resin. And those made of polyvinyl chloride resin, etc., but those made of polyimide resin or polyester resin are preferable because of their excellent heat resistance.

  As the resin film of the insulating coating layer 6, those made of various resins as described above can be used, but those made of polyimide resin or polyester resin are preferable because of their excellent heat resistance.

  The thickness of the base film layer 4 and the insulating coating layer 6 can be appropriately selected, and is, for example, 5 to 100 μm, and preferably 10 to 40 μm.

  The bonding member 3 disposed between the flexible printed wiring boards 2 is one in which adhesive layers 8 are formed on both surfaces of a base film layer 7.

  The base film layer 7 of the joining member 3 is made of a resin film. Examples of such a resin film include a polyimide resin, an acrylic resin, a polyether nitrile resin, a polyether sulfone resin, a polyester resin, a polyethylene naphthalate resin, and a polyethylene resin. Examples thereof include those made of a vinyl chloride resin and the like, and those made of a polyimide resin or a polyester resin are preferable because of their excellent heat resistance.

  The thickness of the base film layer 7 of the joining member 3 can be appropriately selected, and is, for example, 10 to 100 μm, and preferably 20 to 60 μm.

  The adhesive layer 8 may be made of an adhesive similar to an adhesive generally used for producing a film adhesive called a bonding sheet. For example, nylon / epoxy resin, acrylic / phenol, polyester / epoxy resin And an adhesive such as nitrile rubber (NBR) / epoxy resin. The thickness of the adhesive layer 8 is preferably, for example, 5 to 20 μm.

  In the multilayer flexible printed wiring board 1 of the present invention, as shown in FIG. 2, for example, through holes 9 may be formed as necessary to connect the conductive layers 5 formed on each flexible printed wiring board 2.

  As described above, the multilayer flexible printed wiring board 1 of the present invention has been described. However, the multilayer flexible printed wiring board 1 of the present invention is not limited to the two flexible printed wiring boards 2 joined by the joining member 3 as described above. Three or more flexible printed wiring boards 2 may be joined by the joining member 3.

  Next, the method of manufacturing the multilayer flexible printed wiring board 1 according to the present invention will be described with reference to an example of manufacturing the multilayer flexible printed wiring board 1 having two flexible printed wiring boards 2.

  First, in manufacturing the multilayer flexible printed wiring board 1, as shown in FIG. 3, two flexible printed wiring boards 2 and one joining member 3 for joining them are prepared.

  The flexible printed wiring board 2 is manufactured by an ordinary method of manufacturing a flexible printed wiring board. For example, an electrolytic copper foil or a rolled copper foil is coated on both sides of a base film layer 4 made of a resin film with a desired wiring. A conductive layer 5 formed in a pattern is formed, and an insulating coating layer 6 made of a resin film is formed on the base film layer 4 and the conductive layer 5.

  The base film layer 4 of the flexible printed wiring board 2 is made of a resin film. Examples of such a resin film include polyimide resin, acrylic resin, polyether nitrile resin, polyether sulfone resin, polyester resin, and polyethylene naphthalate resin. And those made of polyvinyl chloride resin, etc., but those made of polyimide resin or polyester resin are preferable because of their excellent heat resistance.

  As the resin film of the insulating coating layer 6, those made of various resins as described above can be used, but those made of polyimide resin or polyester resin are preferable because of their excellent heat resistance.

  The thickness of the base film layer 4 and the insulating coating layer 6 can be appropriately selected, and is, for example, 5 to 100 μm, and preferably 10 to 40 μm.

  The bonding member 3 disposed between the flexible printed wiring boards 2 is one in which adhesive layers 8 are formed on both surfaces of a base film layer 7.

  The base film layer 7 of the joining member 3 is made of a resin film. Examples of such a resin film include a polyimide resin, an acrylic resin, a polyether nitrile resin, a polyether sulfone resin, a polyester resin, a polyethylene naphthalate resin, and a polyethylene resin. Examples thereof include those made of a vinyl chloride resin and the like, and those made of a polyimide resin or a polyester resin are preferable because of their excellent heat resistance.

  The thickness of the base film layer 7 of the joining member 3 can be appropriately selected, and is, for example, 10 to 100 μm, and preferably 20 to 60 μm.

  The adhesive layer 8 may be made of an adhesive similar to an adhesive generally used for producing a film adhesive called a bonding sheet. For example, nylon / epoxy resin, acrylic / phenol, polyester / epoxy resin And an adhesive such as nitrile rubber (NBR) / epoxy resin.

  The adhesive layer 8 can be formed on the base film 7 by, for example, applying the above-mentioned adhesive to both surfaces of the base film layer 7. The thickness of the adhesive layer 8 is preferably, for example, 5 to 20 μm.

  The two flexible printed wiring boards 2 thus obtained and one joining member 3 are joined by superposing the flexible printed wiring boards 2 on both sides of the joining member 3, in other words, joining the flexible printed wiring boards 2. The members 3 are superposed so as to sandwich them, and are pressurized and heated to be integrated. The integrated flexible printed wiring board 2 and joining member 3 in this way become a multilayer flexible printed wiring board 1 as shown in FIG.

  Pressing and heating can be performed using a heating and pressing device such as a hot pressing device and a heating and pressing roller. The conditions of pressurization and heating are preferably selected as appropriate according to the number of laminations of the flexible printed wiring board 2 and the joining member 3 and the like. C. is preferred.

  When manufacturing the multilayer flexible printed wiring board 1 having the through holes 9 as shown in FIG. 2, for example, when manufacturing each flexible printed wiring board 1 and the joining member 3, drilling, laser drilling, etching, etc. The hole is formed by using the known method.

  Then, the flexible printed wiring board 2 in which the holes are formed and the joining member 3 are alternately overlapped so that the positions of the holes match, and are pressurized and heated to be integrated. Further, the through hole 9 can be formed by plating a metal such as copper, nickel, gold, solder, or an alloy thereof around the hole.

  As described above, the production of the multilayer flexible printed wiring board 1 having the structure using two flexible printed wiring boards 2 has been described, but the production of the multilayer flexible printed wiring board 1 having the structure using three or more flexible printed wiring boards 2 is also the same. You can do it.

  That is, the flexible printed wiring board 2 and the joining member 3 are alternately overlapped so that both ends become the flexible printed wiring board 2, and are pressurized and heated to be integrated to form the multilayer flexible printed wiring board 1. Can be manufactured.

Sectional view showing an example of the multilayer flexible printed wiring board of the present invention. Sectional view showing another example of the multilayer flexible printed wiring board of the present invention. Sectional view showing an example of a method for manufacturing a multilayer flexible printed wiring board of the present invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 ... Multilayer flexible printed wiring board, 2 ... Flexible printed wiring board, 3 ... Joining member, 4 ... Base film layer of flexible printed wiring board, 5 ... Conductive layer, 6 ... Insulating coating layer, 7 ... ... Base film layer of joining member, 8 ... Adhesive layer, 9 ... Through hole

Claims (4)

A multilayer flexible printed wiring board formed by laminating a plurality of flexible printed wiring boards,
The flexible printed wiring board according to claim 1, wherein the flexible printed wiring board is laminated via a bonding member having adhesive layers formed on both surfaces of a base film layer made of a resin film.   2. The multilayer flexible printed wiring board according to claim 1, wherein the resin film is a polyimide film or a polyester film. A method of manufacturing a multilayer flexible printed wiring board obtained by laminating a plurality of flexible printed wiring boards,
A step of alternately overlapping the flexible printed wiring board and a joining member having an adhesive layer formed on both surfaces of a base film layer made of a resin film,
A process in which the flexible printed wiring board and the joining member are alternately overlapped to be integrated by pressurizing and heating.   4. The method according to claim 3, wherein the resin film is a polyimide film or a polyester film.

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