JPS6025715A - Manufacture of laminate - Google Patents

Abstract

PURPOSE:To obtain a laminate that would be less warped, by placing, outside of a mirror plate situated nearest to a hot platen, a cushioning material and then another mirror plate, and heating and pressing a prepreg between hot platens, so that the properties of the laminate would not be lowered and the forming pressure between the hot platens is made uniform. CONSTITUTION:One or more pregregs are placed between mirror plates (preferably mirror plates high in hardness for example stainless steel plates or the like), and such sets are introduced between hot platens. In this case, a cushioning material (e.g. kraft paper, rubber, etc.) and then another mirror plate (preferably one that is high in modulus in flexture and hardness and thick) are placed outside of the mirror plate situated nearest to the hot platen, and forming under heating and pressure is carried out to produce a laminate. EFFECT:The thermal conductivity is uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a laminate whose purpose is to reduce warping of the laminate located at the location closest to the heat transfer during molding.

Generally, laminates are made by impregnating a base material such as paper or glass cloth with thermosetting resin and sandwiching the B-staged sheets between mirror-surfaced plates.
After 6 to 8 sets of these are placed between hot plates, they are heated and pressed to produce the product. By the way, in printed wiring board manufacturing, recently,
As wiring circuit designs have become more dense and processing processes have become more automated, strict requirements have been placed on reducing warping of the laminates that serve as substrates.

However, in the production of laminates, in order to increase productivity, multiple sets of prepregs are usually placed between the heating plates as described above, and the laminates formed near the heat transfer are formed in the center. The warpage was larger than that of the previous one, and this caused problems when processing printed wiring boards.

In order to solve the problems of C and C of the present invention, we conducted intensive research and found that by layering a cushioning material and another mirror plate on the outside of the mirror plate closest to the heat transfer in this order, we could create a laminated board. It has been found that the warpage of a laminate formed near the thermal transition can be made as small as the warpage of a laminate formed in the center without degrading the overall properties. In the present invention, the molding pressure is uniform between the prepreg located near the heat transfer and the prepreg located in the center between the hot platens, and heat conduction is also uniform, so the desired purpose is achieved. It is assumed that it is possible.

The material of the mirror plate is not particularly limited, but a material with high hardness is desirable. Jffi usually uses stainless steel plate. Furthermore, the cushion pad placed on the outside of the mirrored plate closest to the heat exchanger is not particularly limited and may be made of kraft paper, rubber, asbestos, or the like. Further, the mirror plate overlaid on the cushioning material may or may not be the same as the other mirror plates, but it is desirable that the mirror plate has a large bending elastic modulus and hardness and is large in thickness.

The resin for the laminate used in the present invention is generally a thermosetting resin, but a thermoplastic resin can also be used. Further, the base material may be paper, glass, synthetic fiber, etc., and is not particularly limited.

Examples of the present invention will be described.

Example 1 Eight sheets of paper-based phenolic resin prepregs with 35μ thick copper foil placed on both sides were sandwiched between 15mm thick mirrored plates made of stainless steel, and the 8 sets were placed between hot plates. throw into. On the outside of the mirror plate closest to the heat transfer, there are two sheets of kraft paper, and a John material and the same mirror plate as above are stacked in this order, and a cushioning material made of 20 sheets of kraft paper is placed between the heat transfer and the heat transfer. Through the intervention of Wang Riki + o o Ky
/d for 70 minutes.

Example 2 Heat and pressure molding was carried out in the same manner as in Example 1 except that two sheets of cushioning material made of kraft paper and a 25 mm thick mirror plate made of stainless steel were stacked in this order on the outside of the mirror plate closest to the heat transfer. did.

Comparative Example A cushioning material made of two pieces of kraft paper and a mirror plate were placed on the outside of the mirror plate closest to the heat transfer (other than that, heat and pressure molding was performed in the same manner as in Example 1).

Regarding the double-sided copper-clad laminates with a thickness of 1 and 6 mm obtained in Examples and Comparative Examples, laminate A was formed at the position closest to the heat transfer.
Table 1 shows the properties of the laminate B formed in the center between the hot platens.

In addition, the solder resistance and insulation resistance in Table 1 are J I
Measured in accordance with SC-6481. The amount of warpage of the laminate was determined by etching a 400 x 400 carp specimen over the entire surface and measuring the warp after heating it at 150°C for 30 minutes according to JIS-C.
Measured in accordance with 6481.

Table 1 As is clear from Table 1, according to the present invention, the warpage of the laminate formed near the heat transition can be reduced to the same level as the warpage of the laminate formed in the center between the hot platens. You can, and it's hot! The warping of the laminate itself, which is formed in the center, was also reduced compared to conventional products. Furthermore, it does not cause any decrease in semi-Il resistance or insulation resistance, and its industrial value is extremely great.

patent applicant

Claims (1)

[Claims] When one or more prepregs are sandwiched between mirror plates and multiple sets of prepregs are heated and pressed between hot platens, a cushioning material and one more mirror plate are placed on the outside of the mirror plate located closest to the heat transfer. A method for manufacturing laminates characterized by sequential stacking.