JPS60950A - Manufacture of laminated board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminated board used as an electrically insulating board, etc., and an object of the present invention is to suppress the occurrence of warping and twisting.

Synthetic resin laminates are made by impregnating one continuous sheet-like fibrous base material such as paper, glass woven fabric, glass non-woven fabric, cloth, etc. with synthetic resin varnish such as phenolic resin or epoxy resin and drying it to a predetermined length. It is manufactured by cutting a predetermined number of sheets and stacking them under heat and pressure. prepreg.

The prepregs are cut to a predetermined length and stacked, and when manufacturing a laminate, a predetermined number of the stacked prepregs are taken out and stacked in the order in which they were stacked for convenience of work, resulting in uneven coating. Since this unevenness tends to occur continuously, the distortion appears as amplified in laminates manufactured by stacking a predetermined number of sheets using the method described above, and is further caused by heating during punching, etc. There is a tendency to warp, twist or increase.

In view of the above points, it is an object of the present invention to suppress the occurrence of warping and twisting of a laminate due to uneven paper manufacturing of the base material and uneven coating of resin varnish.

The method of the present invention is a method for manufacturing a laminate, which comprises stacking a predetermined number of prepregs obtained by impregnating and drying a synthetic resin face into a sheet-like base material, alternating the front and back sides of the prepregs, and subjecting the prepregs to heat and pressure molding. It is. According to the present invention, even if the lofts of the prepregs are the same, by stacking the prepregs by rubbing the front and back sides of the prepregs alternately, it is possible to cancel out the unevenness of papermaking and the unevenness of resin coating, resulting in uniform lamination. board or obtained. In the conventional method, if prepregs from the same lot are used, there will be uneven fabrication of the base material, uneven coating of the resin, or overlapping distortions when the laminate is made.

Next, the present invention will be explained in detail.

Example 1 11 mils bleached kraft paper was impregnated with 45-48% of tung oil modified phenolic resin and dried, 1055+m x 1055mm.
Stack three sheets of pre-preg cut into layers with the front and back sides alternately placed, place copper foil on the surface, and heat this at a temperature of 170℃ and a pressure of 80#.
α6I11++ was laminated for 60 minutes under the conditions of /cr/l.
+ thick copper-clad laminate was obtained. This is called Invention A.

Example 2 The prepreg obtained in the same manner as in Example 1 was turned upside down alternately.
Strained, stacked 8 sheets, and laminated them under the same conditions as Example 1.
, a copper-clad laminate with a thickness of 6 mm was obtained. This will be referred to as Invention B.

Example 3 Twelve sheets of prepreg obtained in the same manner as in Example 1 were stacked with the front and back sides alternated, and laminated and molded under the same conditions as in Example 1.
．． A copper-clad laminate having a thickness of 5 mm was obtained. This will be referred to as Invention C.

Comparative Examples 1 to 3 Examples 1 to 3 except that the same prepregs as in Example 1 were stacked in one direction (without rubbing the front and back sides alternately).
3, respectively 0.6m and 1.611III
A copper-clad laminate having a thickness of I, Z5+nm was obtained. These laminates are referred to as comparative products D and ElF, respectively.

Each laminate obtained in the above Examples and Comparative Examples was
Table 1 shows the results of measuring the twisting and warpage of a sample cut to 320 m, printed and etched on copper foil, and then adjusted to 300 using a 60 nibble, and the same sample heat-treated at 160°C for 60 minutes. show. The number of samples was 20 each.

The method for measuring torsion is to place a sample on a table with its curved convex surface facing up, press each of the four corners, and calculate the maximum value of the uplift of the diagonal corners. In addition, the method for measuring warpage is to place the sample on a table with the convex surface facing up, and measure the inner curvature from the table surface to the highest position of the convex portion of the sample.

Table 1 As can be seen from the results in Table 1, according to the present invention, a good laminate was obtained with no twisting and little variation in warpage.

As explained above, sheet-like materials that are generally manufactured continuously (paper, glass cloth, glass non-woven fabric, prepreg using cloth, etc.) have a certain tendency (unevenness) in density distribution in the machine direction. This tendency is amplified in the laminate obtained by stacking the sheets in the same cutting order. However, in the present invention 1, since the laminate is stacked with the front and back sides alternately stacked, these density distributions (unevenness) are canceled out, and the laminate becomes uniform and has no twist or warpage. I can do it.

patent applicant

Claims (1)

[Claims] A method for manufacturing a laminate, which comprises stacking a predetermined number of prepregs obtained by impregnating and drying a synthetic resin into a sheet-like base material, alternating the front and back sides, and heating and pressurizing the prepregs.