JPS6287331A - Manufacture of metal foil-clad laminated sheet - Google Patents

Abstract

PURPOSE:To eliminate dents on the surfaces of metal foils developing above through holes and at the same time make the bending and drawing of a laminated sheet possible by a method wherein the metal foils are respectively laminated through insulating layer onto the surfaces of a metal board by hardening resin after the metal board, in through holes bored in which the resin is filled, and the metal foils, on one surface of each of which a resin layer is provided, are piled up one upon another. CONSTITUTION:Firstly, a metal board 2 and a resin-impregnated base material 4 are molded integrally so as to flow the resin in the resin-impregnated base material 4 out of the base material 4 into through holes 1... so as to fill the through holes 1... with the resin 3. After that, the resin-impregnated base material 4 is removed. Secondly, metal foils 7 and 8, on one surface of which resin layers 5 and 6 are provided respectively, are prepared so as to put them on both surfaces of the metal board 2 in such a manner that the resin layers 5 and 6 are pinched between the metal board 2 and the metal foils 7 and 8. Finally, the resin 3 filled in the through holes 1... and the resin in the resin layers 5 and 6 are hardened so as to obtain a metal foil-clad laminated sheet, which is formed by laminating the metal foils 7 and 8 through insulating layers 9 and 10 consisting of hardened resin onto both the surfaces of the metal board.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for manufacturing a metal foil-clad laminate used as a printed wiring board.

[Background technology]

Conventionally, a metal foil-clad laminate in which metal foil is laminated on at least one surface of a metal substrate having through holes with an insulating layer interposed therebetween has been obtained in the following manner. That is, a metal foil with a resin layer provided on one side is prepared, and after the metal foil and the metal substrate are overlapped with the resin layer facing the metal substrate, the resin in the resin layer is cured. be.

However, the metal foil laminate obtained in this way,
A large depression was formed on the surface of the metal foil above the through hole. Therefore, an insulating layer is formed by sandwiching a resin-impregnated base material between a metal substrate and a metal foil and curing the resin, thereby obtaining a metal foil-clad laminate containing the base material in the insulating layer. I made it. This metal foil-clad laminate has no depressions on the surface of the metal foil, but since the insulating layer includes a base material, it cannot be bent or drawn, which has hindered miniaturization of electronic devices using it.

[Purpose of the invention]

In view of the above circumstances, the present invention provides a method for manufacturing a metal foil-clad laminate that has no depressions on the surface of the metal foil above the through-holes and is capable of bending and drawing. The purpose is to provide

[Disclosure of the invention]

In order to achieve the above object, the present invention includes filling resin into the through holes of a metal substrate having through holes,
After overlapping a metal foil with a resin layer on one side on at least one side of a metal substrate so that the resin layer is sandwiched between the metal substrate and the metal foil, the resin of the resin layer and the inside of the through hole are stacked. The gist is a method for manufacturing a metal foil laminate in which a metal foil is laminated on at least one surface of a metal substrate via an insulating layer by curing the resin filled in the metal foil laminate. do.

An embodiment of this will be explained in detail below based on the accompanying drawings.

As shown in FIG. 1 (al), a metal substrate 2 having a through hole and a base material 4 impregnated with resin are prepared.

As shown in Fig. 1 (bl), the metal substrate 2 and the resin-impregnated base material 4 are integrally molded, and the resin impregnated in the resin-impregnated base material 4 flows out into the through-hole.・
Fill the inside with resin 3. Then, as shown in FIG. 1 (C1), the resin-impregnated base material 4 is removed. Next, as shown in FIG.
), a metal foil (for example, copper foil) 7.8 having resin layers 5 and 6 on one side is prepared, and these are placed in the first layer.
As shown in FIG.'(e), the resin layers 5 and 6 are sandwiched between the metal substrate 2 and the metal foils 7 and 8, and are stacked on both sides of the metal substrate 2, respectively. After this, through-hole...
The resin 3 filled in the inside and the resin of the resin layer 5.6 are cured, and metal foils 7 and 8 are laminated on both sides of the metal substrate via insulating layers 9 and 10 made of the cured resin. Try to get a laminate. Circular No. 14 shows the cured resins of the filling resin 3 and the resin layers 5 and 6.

It is desirable that the resin 3 filled in the through hole and the resin of the resin layer 5.6 react with each other. For example, a resin 3 filled in a through hole and a resin layer 5.
Both resins in No. 6 are epoxy resins or polyimide resins. The metal foil with a resin layer on one side is
As shown in the figure, the resin layer 11 may be composed of two layers, a resin film layer 12 and a resin adhesive layer 13, and the resin film layer 12 may be in contact with the metal foil 7 (8).

In this case, the resin film preferably stretches by 40% or more. For example, polyimide film can be mentioned.

As seen above, the method for manufacturing a metal foil-clad laminate according to the present invention is to fill the through holes of a metal substrate having through holes with resin, and then overlay the metal foil with a resin layer on one side. I try to match it. Since the through-holes are filled with resin and the surface of the metal substrate is flattened, no depressions are formed on the metal foil surface above the through-holes in the obtained metal foil-clad laminate. Furthermore, since a metal foil-clad laminate whose insulating layer does not contain a base material can be obtained, bending and drawing are possible.

The method for manufacturing a metal foil-clad laminate according to the present invention is not limited to the above embodiments. In order to improve mechanical strength and heat dissipation, an appropriate amount of an inorganic filler may be mixed into the resin filled in the through hole and the resin of the resin layer.

〔Effect of the invention〕

As described above, the method for manufacturing a metal foil-clad laminate according to the present invention is to fill resin into the through holes of a metal substrate having through holes, and to apply a metal foil having a resin layer on one side to the metal foil. After the resin layer is sandwiched between a metal substrate and metal foil and superimposed on at least one surface of the substrate, the resin of the resin layer and the resin filled in the through holes are cured to form a metal substrate. A metal foil-clad laminate is obtained in which metal foil is laminated on at least one surface of the metal foil with an insulating layer interposed therebetween. Therefore, depressions are not formed on the surface of the metal foil above the through-holes in the obtained metal foil-clad laminate. Moreover, since a metal foil-clad laminate whose insulating layer does not contain a base material can be obtained, bending and drawing are possible. Therefore, if the metal foil-clad laminate obtained by the manufacturing method according to the present invention is used in electronic devices, etc., it becomes possible to downsize the electronic devices.

[Brief explanation of drawings]

Figure 1 (a), (b), (C1, (d), (e)
2 is an explanatory diagram of an embodiment of the method for manufacturing a metal foil-clad laminate according to the present invention, and FIG. It is a sectional view showing an example of foil. 1...Through hole 2...Gold JXi plate 3...
Resin filled in through hole 4...Resin-impregnated base material 5.6.11...Resin layer 7.8...Metal foil 1
2...Resin film layer 13...Resin adhesive layer Agent Patent attorney Takehiko Matsumoto District 1 (a)

Claims (3)

[Claims] (1) The through holes of a metal substrate having through holes are filled with resin, and a metal foil with a resin layer on one side is placed on at least one side of the metal substrate. After being sandwiched and superimposed, the resin of the resin layer and the resin filled in the through hole are cured, and a metal foil is laminated on at least one surface of the metal substrate with an insulating layer interposed therebetween. A method for producing a metal foil-clad laminate so as to obtain a foil-clad laminate. (2) The method for manufacturing a metal foil-clad laminate according to claim 1, wherein the resin layer is composed of two layers: a resin film layer and a resin adhesive layer, and the resin film layer is in contact with the metal foil. (3) Filling the through hole with resin involves overlaying the resin-impregnated base material on a metal substrate, allowing the resin impregnated in the base material to flow into the through hole, and then removing the base material. A method for manufacturing a metal foil-clad laminate according to claim 1 or 2, which is performed by: