JP2864276B2 - Manufacturing method of printed wiring board - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a printed wiring board based on a metal plate such as an aluminum plate or a copper plate. And a method for manufacturing a printed circuit board with improved characteristics.

[Conventional technology]

Conventionally, as a method of manufacturing a printed wiring board based on a metal plate, for example, FIG. 3 (a) → FIG. 3 (b) →
FIG. 3 (c) → FIG. 3 (d) → FIG. 3 (g) → FIG. 3 (h) shows a first manufacturing method, and FIG. 3 (a) →
FIG. 3 (b) → FIG. 3 (c) → FIG. 3 (e) → FIG. 3 (f) → FIG. 3 (g) → FIG. 3 (h)
Is known.

That is, in the first manufacturing method, a through hole 2 having a predetermined size is formed in a metal base plate 1 such as an aluminum plate or a copper plate shown in FIG. 3A by a drill or a punching press (FIG. 3). (B)), as shown in FIG. 3 (c), a metal foil 4 is adhered to one side surface of the metal base plate 1 via an insulating resin layer 3 having a function as an adhesive. On the other side, a plurality of sheets (2 in this embodiment)
The prepreg sheets 5 are heated and pressurized and attached (FIG. 3D). At this time, as shown in FIG. 3 (g), the resin 6 melted out of the insulating resin layer 3 and the prepreg sheet 5 flows into the through-hole 2 and is filled.
Both surfaces of the metal base plate 1 are covered with the insulating resin layer 3 and the insulating resin layer 7 in which the prepreg sheet 5 is melt-hardened,
The printed wiring board X on which the metal foils 4 are laminated is manufactured.

Then, the printed wiring board X thus manufactured is formed through a through hole 8 concentrically at the center of the through hole 2 as shown in FIG. 3 (h). The printed circuit 9 is formed by removing unnecessary portions by etching treatment, and plating is applied to the inner peripheral surface of the through hole 8 to form a through hole plating layer.
10 is formed to obtain the printed wiring board Y.

In the second manufacturing method, the step of FIG. 3 (d) in the above-described first manufacturing method is changed to the steps of FIG. 3 (e) and FIG. 3 (f). Is exactly the same as the first manufacturing process.

That is, after a metal foil 4 is adhered to one side surface of the metal base plate 1 of FIG. 3 (c) via an insulating resin layer 3 having a function as an adhesive, FIG. After embedding the prefilled hole filling resin 11 as shown in (1), a prepreg sheet 12 is attached to the other side surface of the metal base plate 1 by heating and pressing (FIG. 3 (f)). After molding in this manner, it is exactly the same as FIG. 3 (g) and FIG. 3 (h) in the first manufacturing process.

[Problems to be solved by the invention]

However, in the first manufacturing method as described above, when the prepreg sheet 5 is bonded by heating and pressing in the step of FIG. Is filled into the through-hole 2, the surface of the insulating resin layer 3 and the prepreg sheet 5 corresponding to the amount of the resin are dented, the thickness of the insulating layer becomes uneven, and the surface of the printed wiring board X becomes smooth. As a result, there is a problem that a defective product with poor accuracy is obtained.

In addition, in the case of the second manufacturing method, the hole-filling resin 11 must be molded in advance and filled in the through-hole 2, so that the number of manufacturing steps is increased by two or three steps. There has been a problem that the productivity cannot be improved and the cost increases.

In addition, in the case of the first and second manufacturing methods of the related art, when the number of through holes 8 increases, much labor and time are required to form the through holes 2, and all the through holes 2 are always formed. There is a problem that it is very difficult to accurately process the material.

[Object of the invention]

The present invention has been devised in view of such a conventional problem, and can improve the productivity by reducing the number of processing steps, and can always produce a printed wiring board with high precision. It is an object of the present invention to provide a method for manufacturing a wiring board.

[Means for solving the problem]

The present invention achieves the above object by laminating a metal foil on one surface of an etchable metal plate via an insulating resin layer, heating and pressing the insulating resin layer, and curing the metal base plate. After attaching a protective film on one surface side and a resist film on the other surface, a through hole pattern is drawn on the resist film to form holes serving as through holes in the metal base plate by etching, and both sides of the metal base plate are formed. After the protective film and the resist film are peeled off from the surface, the prepreg sheets are laminated and heated and pressed to fill the resin in the prepreg sheets into the holes.

[Function of the invention]

The present invention is configured as described above, and the formation of the hole serving as the through hole is performed by etching, so that the conventional manufacturing process can be shortened, and the insulating resin layer can be made uniform,
The product accuracy can be improved and the productivity can be improved.

(Example of the invention)

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

The same components as those of the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

FIGS. 1 (a) to 1 (f) are explanatory views of a manufacturing process of a printed wiring board according to an embodiment of the present invention, and show a metal such as an aluminum plate and a copper plate shown in FIG. 1 (a). As shown in FIG. 3B, a metal foil 4 is attached to one side surface of the base plate 1 via an insulating resin layer 3 having a function as an adhesive.

Then, as shown in FIG. 1 (c), the metal base plate 1
After adhering the protective film 12a on one surface of the resist film 12a on the other surface, the resist film 12b
A hole 13 is formed in the metal base plate 1 by etching with a through hole pattern formed thereon (FIG. 1 (d)).

Then, after peeling off the protective film 12a and the resist film 12b from both surfaces of the metal base plate 1, a plurality of prepreg sheets 14 are laminated and heated and pressed as in the conventional case (FIG. 1 (e)). Thereby, the insulating resin layer 3
And the resin 15 melted out from the prepreg sheet 14,
As shown in FIG. 1 (f), both sides of the metal base plate 1 are covered with the insulating resin layer 3 and the insulating resin layer 16 obtained by melting and curing the prepreg sheet 14, as shown in FIG. Thus, the printed wiring board X on which the metal foils 4 are laminated is manufactured.

Then, the printed wiring board X thus manufactured is formed by forming a through-hole concentrically at the center of the hole 13 filled with the resin 15 (not shown), as in the conventional case.
Further, a printed circuit is formed by removing unnecessary portions by etching the metal foil 4 by a conventional method, and plating is performed on an inner peripheral surface of the through hole to form a through hole plating layer (not shown). You get a printed wiring board.

FIGS. 2 (a) to 2 (c) show a second embodiment of the present invention, and the second embodiment is a first embodiment of the first embodiment.
1A to 1D, after a hole 13 serving as a through hole is formed in the metal base plate 1, in another process,
An inner layer material 18 as shown in FIG. 2 (a) is prepared. The inner layer material 18 is manufactured by a general method of manufacturing a multilayer board. For example, a double-sided copper-clad laminate is surface-adjusted, a photosensitive photoresist is laminated on the surface, and exposure, development, etching, Circuits 17 and 17 'are formed on both sides through steps such as photo resist stripping. In this way, one of the laminated boards having the circuits 17, 17 'formed on both sides is used as the inner layer material 18.
Or several of them are epoxy resin on glass cloth,
This is an inner layer material 18 laminated via a prepreg impregnated with a polyimide resin, a modified polyimide resin or the like.

As shown in FIG. 2 (a), the inner layer material 18 prepared as described above is placed on both sides of the inner layer material 18 by the prepreg sheets 14,1.
4 ′, the metal base plates 1, 1 ′ manufactured by the steps of FIGS. 1 (a) to 1 (d)
By laminating those that formed holes 13 that will be through holes,
Heating and pressurizing.

Thereby, the insulating resin layer 3 and the prepreg sheet
As shown in FIG. 2 (b), the resin 15, 15 'melted and flowed out of the inside 14, 14' is filled into the hole 13, and the insulating resin layer 3 and the prepreg sheets 14, 14 are filled. ′ Is a metal base plate 1,1 ′
Both sides are covered, and through holes 8, 8 as before.
8 'is molded through, and as shown in FIG.
A printed circuit is formed on each of the printed circuit boards 4 'and 4' by plating the inner peripheral surfaces of the through holes 8 and 8 'to form a through-hole plating layer 10.
Is to manufacture.

The present invention is for manufacturing a printed wiring board by the steps as described above, and in particular, by forming the holes 13 to be through holes by etching, even if the number of through holes increases, it is possible to simultaneously mold by one positioning. ,
In addition to improving the molding accuracy, the conventional hole forming step and the step of filling the hole with resin can be shortened, the thickness of the insulating resin layers 3 and 16 can be made uniform, and the product accuracy can be improved.
Productivity can be improved.

〔The invention's effect〕

According to the present invention, a metal foil is laminated on one surface of a metal plate that can be etched as described above via an insulating resin layer, and the insulating resin layer is heated and pressurized and cured, while one of the metal base plates is cured. After sticking a protective film on the front surface side and a resist film on the other surface, a through hole pattern is drawn on this resist film to form holes serving as through holes in the metal base plate by etching, and from both surfaces of the metal base plate. After peeling off the protective film and the resist film, the resin in the prepreg sheet is filled into the holes by laminating the prepreg sheets and applying heat and pressure, so that the following excellent effects can be obtained.

(A). By performing the formation of the through holes by etching, even if the number of through holes is large, the through holes can be simultaneously formed by a single positioning, and the forming accuracy is improved.

(B). Since the conventional hole making step and the step of filling the hole with resin can be shortened, productivity can be improved.

(C). In addition, the metal substrate becomes universal and can be used for a variety of wiring boards, which is extremely effective for high-mix low-volume production.

[Brief description of the drawings]

1 (a) to 1 (f) are explanatory views of a manufacturing process of a printed wiring board showing an embodiment of the present invention, and FIG. 2 (a).
2 (c) are explanatory views of a manufacturing process of a printed wiring board according to a second embodiment of the present invention, and FIGS. 3 (a) to 3 (h) are manufacturing diagrams of a conventional printed wiring board. It is explanatory drawing of a process. 1 ... metal base plate, 3 ... insulating resin layer, 4 ... metal foil, 12a ... protective film, 12b ... resist film,
13 ... holes, 14 ... prepreg sheet, 15 ... resin.

Claims (1)

(57) [Claims] A metal foil is laminated on one surface of a metal plate capable of being subjected to an etching treatment via an insulating resin layer, and the insulating resin layer is heated and pressurized and cured, while one surface of the metal base plate is cured. Protective film, after attaching a resist film to the other surface, forming a hole to be a through hole in the metal base plate by etching processing by drawing a through hole pattern in the resist film, a protective film and a protective film from both surfaces of the metal base plate A method for manufacturing a printed wiring board, comprising: laminating a prepreg sheet after removing a resist film, and heating and pressurizing the prepreg sheet to fill the resin with the prepreg sheet into the holes.