JPH03165091A - Manufacture of wiring circuit body - Google Patents

Abstract

PURPOSE:To form a wiring circuit body which has a small electric resistance and generates little heat by transferring wiring circuits that are formed on a metallic board to an adhesion tape to obtain a carrier tape and supplying molding materials to cavities of a mold and also extending the carrier tape until its tape abuts upon an inner wall of each cavity in the mold and then, carrying out molding. CONSTITUTION:Prescribed wiring circuits 2 which are equipped with throughholes 11 are manufactured by press working of a metallic board 1 and the wiring circuits which are stamped out are housed in the original metallic board 1. The surface of an adhesion tape 3 consisting of a film 5 to which adhesive 4 is applied is bonded to the metallic board 1 in tight contact and further, the adhesion tape 3 is peeled off from the board 1 and each wiring circuit 2 is transferred from the board 1 to the tape 3. The adhesion tape 3 with the wiring circuits 2 is used as a carrier tape and the wiring circuits 2 are sandwiched by molds 6 and 7. Then, molding materials 8 are supplied to cavities 10 and the tape 3 is extended until its tape abuts upon the inner wall of each cavity in the mold 6. After that, molding is performed. Subsequently, the adhesion tape 3 is peeled off and a wiring circuit body 9 which is equipped with the wiring circuits 2 on the surface of the compact is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a printed circuit body that can be used as a printed wiring board.

In particular, the present invention relates to a method for manufacturing printed wiring boards using a dry method.

[Conventional technology]

In recent years, wet method 1 of the subtractive method has been applied to metal-clad laminates.
Instead of the manufacturing method of obtaining printed wiring boards by the method, Japanese Patent Application Laid-Open No. 62-280018 and Japanese Patent Application Laid-Open No. 62-291995
A method for manufacturing printed wiring boards using a dry method is proposed in the publication. However, the wiring circuits of printed wiring boards using the transfer method shown in these publications are printed with conductive ink on an insulating base sheet or with conductive paint on an insulating support film; Both had problems in that the electrical resistance of the wiring circuit was high, and on the other hand, they generated significant heat when current was passed through them. Furthermore, there was also a problem in that the insulating base sheet or support film was stretched by the supply pressure of the material during molding, resulting in disconnection of the wiring circuit.

[Problem B to be Solved by the Invention] The present invention provides a printed wiring board that has a wiring circuit that has low electrical resistance, generates little heat when a current is passed through it, and that does not cause disconnection of the wiring circuit during the molding process for forming the wiring circuit body. An object of the present invention is to provide a method for manufacturing a wiring circuit body which can be obtained by a single dry method.

[Means to solve the problem]

The present invention has been made in view of the above points, and a wiring circuit is punched out from a metal plate by a pushback method to form a wiring circuit on the metal plate. Adhesive tape is attached to this metal plate, and the wiring circuit is transferred to the adhesive tape. Using the adhesive strip to which the wiring circuit has been transferred as a carrier tape, the wiring circuit is installed at a predetermined position in the molding die. A molding material is supplied to the cavity of the molding die, and the carrier tape is stretched by the supply pressure until it comes into contact with the inner wall of the cavity of the mold, thereby performing molding. It is characterized by consisting of zero or more steps of peeling off the carrier tape from a molded product having the carrier tape obtained by molding disposed as the outermost layer, and obtaining a wired circuit body in which the wiring circuit is disposed on the surface of the molded product. An object of the present invention is to provide a method for manufacturing a wired circuit body.

The present invention will be explained below.

An example of a wiring circuit body obtained by the manufacturing method of the present invention is shown in FIG.

The embodiment shown in FIG. 1 can be manufactured in accordance with the steps (a) to (f) in FIG. 2, which are shown in the X-Y section of FIG. 1.

FIG. 2(a) A predetermined wiring circuit 2 having a through hole 11 is pressed from a metal plate 1 using a push-back method, and the punched wiring circuit is placed in the original metal plate 1.

Next, the pressed metal plate is degreased, washed and dried.

FIG. 2(b) The side coated with the adhesive 4 of the adhesive tape 3 consisting of the film 5 with the adhesive 4 coated on one side,
It is attached to the metal plate 1 described above.

FIG. 2(c) The adhesive tape 3 is peeled off from the metal plate 1, and at the same time, the wiring circuit 2 is transferred from the metal plate 1 to the adhesive tape 3.

FIG. 2(d) Using the adhesive tape 3 with the wiring circuit 2 attached thereto as a carrier tape, the wiring circuit 2 is sandwiched and placed between the molding molds 6.7.

FIG. 2(e) The molding material 8 is supplied to the cavity lO formed by the mold 6.7, and the pressure of the supply is applied to the adhesive tape 3.
After stretching until it touches the inner wall of the cavity of the mold 6, molding is performed.

Second [ff1 (f) The adhesive tape 3 is peeled off from the wiring circuit body 9 of the molded product having the adhesive tape 3 as the outermost layer, and the wiring circuit body 9 having the wiring circuit 2 on the surface of the molded product can be manufactured.

The following materials can be used to manufacture the above wiring circuit body.

As the metal plate 1 forming the wiring circuit 2 of the wiring circuit body 9,
Copper, iron, nickel, a! Metals such as reminium, alloys containing these as main components, metal plates such as 4270I, phosphor bronze, and stainless steel can be used. Among these, a copper plate is particularly preferred because of its low electrical resistance.The thickness of the metal plate used is preferably thin for forming fine circuits, but from the viewpoint of handling, a thickness of 0.08 to 0.5 is suitable. In particular, it is preferable to use a metal plate having a thickness of 0.1 to 0.25.

Push-back press processing is used to form the wiring circuit 2 from these metal plates 1. By this method, the punched out wiring circuit 2 is backfilled into the original metal plate l and has almost the same shape as the original flat plate, so the surface coated with the adhesive 4 of the adhesive tape 3 is pressed onto the metal Fi 1. The next step of applying can be easily performed without using any special jig.

Moreover, when the adhesive tape 3 is peeled off, only the wiring circuit 2 is left.
- It can be transferred to the adhesive tape 3 at regular intervals with good dimensional accuracy. Further, when punching out the wiring circuit 2 by press working, it is preferable to simultaneously apply unevenness to the surface of the wiring circuit 2 that contacts the molding material 8, as this will further strengthen the adhesion of the wiring circuit to the molded product.

As the adhesive tape 3, a polybutylene terephthalate film, a polyethylene terephthalate film, a polyimide film, etc. coated or coated with a rubber adhesive and slit to a predetermined width can be used. Before bonding the adhesive tape 3 to the metal plate 1, in order to improve the adhesion between the metal plate 1 and the adhesive tape 3, the metal plate 1 is cleaned to remove oil and dirt that adhered during processing. These conventional pretreatment methods for metal plates can be applied as they are.

The molding material 8 is supplied to the cavity 10 formed by the mold 6.7, and under the pressure of the supply, the adhesive tape 3 is stretched until it comes into contact with the inner wall of the cavity of the mold 6, thereby forming the mold. As the molding material 8, molding materials made of thermosetting resins such as epoxy resins, polyimide resins, phenol resins, polyester resins, fluorocarbon resins, and modified resins thereof can be used. In addition, molding materials made of thermoplastic resins such as polybutylene terephthalate resin, polyphenylene oxide resin, polyether sulfone resin, polyphenylene sulfide resin, polyether ether ketone resin, and modified resins of these resins can be used as appropriate depending on the application. can. As the molding conditions for this molding material 8, the conditions normally used for each molding material can be applied as they are.

Next, the present invention will be explained with reference to Examples and Comparative Examples.

〔Example〕

Example 1 The circuit shown in FIG. 1 with a circuit width of 3 wm was pressed from a 0.2 m thick copper plate by the Jinschbach method, and the punched wiring circuit was backfilled into the original copper plate. This processed copper plate was degreased and cleaned using an ultrasonic cleaning device using a trichlorethylene solution. Next, the adhesive side of a 5C11 wide polyimide film tape coated with a chloroprene rubber adhesive on one side was attached to the copper plate. The adhesive tape was peeled off from the copper plate, and the transferred wiring circuit was placed in a predetermined position of a molding die using the adhesive tape as a carrier tape. The molding die was closed, a phenol molding material was supplied by injection, and the pressure of the injection molding was used to stretch the adhesive tape until it came into contact with the inner wall of the cavity of the mold, thereby forming a molded product. Therefore, a molded article with adhesive tape attached to the outermost layer was obtained. The adhesive tape was peeled off, and the wiring circuit body shown in FIG. 1 could be obtained.

In the wiring circuit body shown in Figure 1, the circuit width is 3cm and the total length is 20mm.
A voltage of 100 V was applied between both ends of the L-shaped wiring circuit of m, and the resistance value was determined. At the same time, the surface temperature of the wiring circuit after 30 minutes had elapsed and the temperature of the wiring circuit before the current was applied were measured using a non-contact type surface thermometer at a room temperature of 23° C., and the difference therebetween was defined as the temperature increase. These results are shown in Table 1.

Example 2 The metal plate of Example 1 was changed to copper alloy number C19400, and
The same procedure as in Example 1 was carried out except that the molding material was changed to a polyphenylene sulfide resin molding material.

Comparative Example 1 The same procedure as in Example 1 was carried out, except that the adhesive tape on which the wiring circuit was transferred from the metal plate of Example 1 was replaced with a carrier tape obtained in the next wiring circuit formation. Conductive copper paste (manufactured by Mitsui Toatsu Chemical Co., Ltd., MDP) was applied on the polyimide film.
-800), a circuit similar to that in Example 1 was printed to a thickness of 70 μl and cured to obtain a carrier tape having a wiring circuit.

Comparative Example 2 The same procedure as Comparative Example 1 was carried out except that the conductive copper paste of Comparative Example 1 was printed to a thickness of 120 μm.

From the results in Table 1 above, it is clear that the
It was confirmed that the wired circuit body, in which the wired circuit was disposed on the surface of the molded product, had low electrical resistance and did not generate heat due to the flow of electricity. In Comparative Example 2, the wiring circuit disposed on the carrier tape was broken due to the expansion of the carrier tape during molding, and the characteristics could not be evaluated.

Table 1 [Effects of the Invention] According to the present invention, a wiring circuit is punched out from a metal plate by a pushback method to form a wiring circuit on the metal plate. Adhesive tape is attached to this metal plate, and the wiring circuit is transferred to the adhesive tape. Using the adhesive tape to which the wiring circuit has been transferred as a carrier tape, the wiring circuit is installed at a predetermined position in the mold. A molding material is supplied to the cavity of the molding die, and the supply pressure stretches the carrier tape until it comes into contact with the inner wall of the cavity of the mold, thereby performing molding. It is characterized by consisting of zero or more steps of peeling off the carrier tape from a molded product having the carrier tape obtained by molding disposed as the outermost layer, and obtaining a wired circuit body in which the wiring circuit is disposed on the surface of the molded product. The manufacturing method of the wiring circuit body has a low electric resistance, low heat generation when current is passed, and a printed wiring board that does not break in the wiring circuit during the molding process to form the wiring circuit body is manufactured using the dry method 1 method. It can be obtained with

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a wiring circuit body obtained by implementing the present invention. 2(a) to 2(f) show an embodiment of the present invention shown in a section corresponding to the x-y cross section of FIG. 1.

Claims (1)

[Claims] (1) A wiring circuit is punched out from a metal plate using a pushback method to form a wiring circuit on the metal plate. Adhesive tape is attached to this metal plate, and the wiring circuit is transferred to the adhesive tape. Using the adhesive tape to which the wiring circuit has been transferred as a carrier tape, the wiring circuit is installed at a predetermined position in the mold. A molding material is supplied to the cavity of the molding die, and the supply pressure stretches the carrier tape until it comes into contact with the inner wall of the cavity of the mold, thereby performing molding. The carrier tape is peeled off from a molded product having the carrier tape obtained by molding disposed as the outermost layer to obtain a wiring circuit body in which the wiring circuit is disposed on the surface of the molded product. A method for manufacturing a wiring circuit body, characterized by comprising the above steps.