JPH01141012A - Preparation of composite laminate sheet - Google Patents

Abstract

PURPOSE:To improve adhesiveness between a glass fabric base material layer and a paper base material layer and to obtain a composite laminate sheet exhibiting no blister at soldering and having excellent heat resistance, by restricting thickness of a resin layer between the paper base material layer connecting with the glass fabric base material contained in the glass fabric base material layer. CONSTITUTION:A glass fabric base material layer 3 is constituted of a glass fabric base material 1 and an epoxy resin 2 with which this glass fabric base material 1 is impregnated and coated. The title laminate sheet is constituted in such a way that thickness (t) of resin between the glass fabric base material 1 contained in the glass fabric base material layer 3 and a paper base material layer 4 connected with the glass fabric base material layer 3 is 20-40mum. The amt. of the epoxy resin between the glass fabric base material 1 and the paper base material 4 thereby reaches an appropriate amt. when pressed under an ordinary pressing condition, namely, 60-100kgf/cm<2> and blister on the interface between the glass fabric base material layer 3 and the paper base material layer hardly occurs even when immersed in solder at 260 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing composite laminates used as electrical insulating boards.

(Prior art and its problems) Conventionally, prepreg made by impregnating a paper base material with epoxy resin has been used as a laminate for processing by punching.
There is a composite laminate made by laminating one or more sheets, further laminating prepregs made of glass cloth base material impregnated with epoxy resin on both sides, and molding them under heat and pressure.

FIG. 1 is a cross-sectional view of the composite laminate. On both sides of the paper base material m4, which is made by laminating a plurality of prepregs made by impregnating a paper base material with epoxy resin, epoxy resin is applied to a glass cloth base material. A glass cloth base material layer 3.3 is provided which is a prepreg impregnated with a glass cloth base material layer 3.3, and in this example, 8 pieces of copper foil 5°5 are roughly coated on both sides as metal foil.

However, the above composite laminate has poor heat resistance because the surface layer is the glass cloth base layer 3 and the middle layer is the paper base layer 4 as described above. , after several minutes, peeling occurs at the interface between the glass cloth base layer 3 and the paper base layer 4, resulting in the problem of swelling 6 as shown in FIG.

(Object of the Invention) In view of the above problems, an object of the present invention is to provide a method for manufacturing a composite laminate having excellent heat resistance.

(Means for Solving the Problems) The present invention consists of stacking a predetermined number of sheets of paper base prepreg impregnated with epoxy resin, and forming a glass cloth base on both sides of the paper base prepreg having a resin thickness of 20 to 40 μm at least on the paper base prepreg side. The present invention relates to a method for manufacturing a composite laminate, which is characterized by stacking prepregs and heating and pressurizing them.

FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. There is. Here, in the present invention, the resin thickness (t in FIG. 2) between the glass cloth base material 1 included in the glass cloth base material layer 3 and the paper base material layer 4 bonded to the glass cloth base material layer 3 is It is configured to have a thickness of 20 μm to 40 μm.

That is, when the thickness of the epoxy resin to be impregnated and coated on the glass cloth base material 1 is in the range of 20 μm to 40 μm as described above, the gf/
When pressurized at cm2, the amount of epoxy resin between the glass fabric 5 base material 1 and paper base material layer 4 becomes appropriate, and even if immersed in solder at 260°C, the glass fabric base material layer 3 and paper base material layer It becomes difficult for the material layer 4 to sag at the interface.

Here, if the resin thickness is less than 20 μm, 260°C
When immersed in solder, swelling occurs at the interface between the glass Uin material layer 3 and the paper base material layer 4.

On the other hand, if the thickness of the resin is 40 μm or more, it will be difficult to uniformly adhere the resin to the glass cloth base material 1, and the amount of resin will be too large, resulting in large warpage and twisting during heat and pressure molding.

(Explanation of Examples) Next, the present invention will be explained with reference to Examples and Comparative Examples.

Example 1 First, two sheets of prepreg A were obtained by impregnating and coating a glass cloth base material with an epoxy laminate resin (DER511, manufactured by Dow Chemical Company) to a resin thickness of 1920 μm. Next, five sheets of prepreg A were obtained by impregnating linter paper with the same resin as that used for molding prepreg A above. Here, one prepreg A is stacked on both sides of the five prepregs a, and copper foil is roughly stacked on both sides of the outer layer, and the temperature is 17.
0°C.

A double-sided copper-clad laminate having a thickness of 1.611III was obtained by heating and pressing at a pressure of 80 gf/ci for 90 minutes.

Example 2 Prepreg B2fi: 4f? which was impregnated and coated with epoxy resin on a glass cloth base material to a thickness of 40 μm. A double-sided copper-clad laminate having a thickness of 1.5 mm was obtained in the same manner as in Example 1 except for the above.

Comparative Example 1 A double-sided copper-clad laminate with a thickness of 1.6 mm was obtained in the same manner as in Example 1, except that a prepreg C@ was obtained by impregnating and coating a glass cloth base material with epoxy resin to a thickness of 5 μm.

Comparative Example 2 A double-sided copper-clad I-layer board with a thickness of 1.6IlIII was obtained in the same manner as in Example 1, except that a glass cloth base material was impregnated and coated with epoxy resin to a thickness of 50 μm. .

Here, the results of the heat resistance 1 warping and twisting tests of the double-sided copper-clad laminates obtained in Example 1.2 and Comparative Example 1.2 are shown in the following table.

(Effects) As described above, the present invention has a resin thickness of 20 μm to 4 μm between the paper base layer bonded to the glass cloth base material included in the glass cloth base layer.
Since it is configured to have a thickness of 0 μm, the adhesion between the glass cloth base material layer and the paper base material layer is improved, and even when immersed in solder at 260°C, the interface between the glass cloth base material layer and the paper base material layer remains intact. Effects include being able to obtain a composite laminate with excellent heat resistance that does not cause swelling, and does not cause swelling when dipping the solder with a solder leveler or when mounting components. has.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional composite laminate in a swollen state, and FIG. 2 is a sectional view taken along the line ■--■ in FIG. 1...Glass cloth base material 2...Epoxy resin 3...Glass cloth base material layer 4...Paper base material layer 5...Copper foil 6...Bulge E-゛)

Claims (1)

[Claims] (1) A predetermined number of sheets of paper base prepreg impregnated with epoxy resin are stacked, and a glass cloth base prepreg having a resin thickness of at least 20 to 40 μm on the paper base prepreg side is stacked on both sides, and then heated and pressurized. A method for manufacturing composite laminates.