JPH04164611A - Manufacture of laminate - Google Patents

Abstract

PURPOSE:To prevent the flowing out of resin from the ends of prepregs in lamination process by a method in which a prepreg is cut into the sizes of two or more times of prescribed size, and the cut prepreg is folded into prescribed size, and then after the rodlike object for preventing the flowing out of resin has been arranged inside of floded back part, it is formed. CONSTITUTION:The prepreg 1 with the size of two times of prescribed size is folded, and a rodlike object 5 is arranged inside of folded back part. Copper foils are superimposed on one or both surfaces of said superimposed prepregs according to necessity, and they are formed under heating and pressurizing. Since the folded back part has a little larger thickness than that of other part, resin may be effectively, from its flowing out, where by the yield and the dimension-accuracy of a laminate may be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is directed to a method for manufacturing a laminate that prevents resin from flowing out from the edges of the prepreg during molding.

[Conventional technology]

Conventionally, methods for reducing the flow of resin from the ends of prepreg include a method of shortening the gel of the prepreg and a method of lowering the molding pressure of the press. However, although these methods are effective to some extent, forming defects occur due to insufficient flow and pressure, so two-stage impregnation, vacuum impregnation, etc. are performed in order to make prepregs with improved impregnation properties, and in presses, I had to do a vacuum press.

[Invention or problem to be solved]

In view of the above-mentioned prior art, the present invention aims to effectively prevent the resin from flowing out from the ends of the prepreg during lamination molding.

[Means to solve the problem]

The present invention provides a method for manufacturing a laminate in which a prepreg obtained by impregnating a fiber base material with a resin varnish is sandwiched between mirror-finished metal plates and molded under heat and pressure. This method of manufacturing a laminate is characterized by cutting the resin into a size, folding it into a predetermined size, and arranging a linear object inside the folded portion to prevent resin from flowing out.

The prepreg used in the present invention is made of glass cloth with a size of about 50 to 300 μm, which is used for ordinary glass epoxy laminates, or is heat-treated as long as it is not likely to be cut by pressing. It may be a plastic woven fabric, a nonwoven fabric, or a nonwoven fabric mixed with glass fiber. These are bent to a predetermined size (usually about the same size as the mirror plate). For items that are difficult to bend, it is best to heat them or apply a light seal to the bent part in advance. Arrange so that the folds touch the periphery of the mirror plate. A necessary number of such prepregs may be used, and if necessary, ordinary prepregs may also be used in combination.

Furthermore, when a plurality of sheets of such prepreg are used, it is preferable that a long object for preventing resin outflow is placed around the entire periphery of the backing sheet.

The present invention will be explained using the drawings. In FIG. 1, a prepreg (1) twice the predetermined size is folded and a linear object (5) is placed inside the folded portion. Figure 2 shows
Such prepreg (+), (2), (3), (4)
The two sheets are stacked one on top of the other in different directions. At that time, it is preferable to align the directions of the fiber base materials.

By overlaying copper foil on one or both sides of these overlapping prepregs as necessary and performing heat and pressure molding under normal molding conditions, resin outflow can be effectively prevented, yields improved, It is possible to improve dimensional accuracy.

[For production]

In the method of the present invention, the prepreg is cut into multiple pieces of a predetermined size, folded to a predetermined size, and a long object is placed inside the fold to prevent resin from flowing out.
The end portion (folded portion) is slightly thicker than the other portions and can effectively prevent resin from flowing out.

It is sufficient to have one linear object for preventing the resin from flowing out on one end surface when stacked. Further, the thickness is preferably about 1 to 3 mm. If the thickness of this long material is too large, there may be no problem in preventing the resin from flowing out, or the molding pressure will not be sufficiently applied to the prepreg laminate, resulting in uneven molding.

The linear material is preferably a flexible material such as cotton, linen, synthetic fiber string, or narrow paper.

〔Example〕

Epoxy resin-impregnated glass cloth prepreg (thickness approx.
0μ) was folded in half, and a hemp string about 2 mm thick was placed inside the folded portion to prevent the resin from flowing out. This is the second
They were stacked as shown in the figure, and 18 μm copper foil was superimposed on both sides, followed by heating and pressure molding using a conventional method to obtain a copper-clad laminate with a thickness of 1.61 mm.

For comparison, eight sheets of prepreg with a length of 530 m and a diameter of 530 m were used, and a thickness of 1 was prepared in the same manner as in the above example.
．． A 6 m copper-clad laminate was obtained.

The moldability, thickness accuracy, etc. of the obtained laminate were measured. The results are shown in Table 1.

Table 1 (Measurement method) 1 Formability The steel foil was removed by etching and the appearance was visually observed.

2. Thickness Accuracy A laminate with a side of 500 U was cut out, the thickness was measured, and the thickness was determined using the following formula.

Maximum Thickness [Effects of the Invention] The method of the present invention can effectively prevent the resin from flowing out from the special end surface of the laminate, which improves the thickness accuracy and appearance of the laminate, and improves the yield of the laminate. improves. Furthermore, in the past, several ω widths were removed from the end of the laminate, but in the present invention, the end to be removed may be only the portion of the linear object.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a prepreg in which a linear object is arranged in the folded portion, and FIG. 2 is a perspective view of four sheets of prepreg shown in FIG. 1 stacked one on top of the other.

Claims (1)

[Claims] (1) In a method for producing a laminate in which a prepreg obtained by impregnating a fiber base material with a resin varnish is sandwiched between metal mirror plates and then heated and press-molded, two or more prepregs of a predetermined size are prepared. A method for manufacturing a laminate, which comprises cutting to size, folding to a predetermined size, and forming a laminate by placing a linear object inside the folded portion to prevent resin from flowing out.