JPS6157629A - Production of laminate - Google Patents

Abstract

PURPOSE:To obtain laminate having improved heat resistance, dimensional stability, and high-frequency electrical characteristics, by blending an unsaturated bond-containing prepolymer with a cyclic polybutadiene uniformly to give prepreg, laminating and pressing it so that it is molded in one piece. CONSTITUTION:A prepolymer obtained from a compound shown by the formula (R1 and R2 are monofunctional organic group and substituent group having unsaturated bond) containing an unsaturated bond in the side chain, such as diallyl phthalate, is uniformly blended with a cyclized butadiene polymer to give a resin composition. A radical polymerization initiator is added to the resin composition, which is impregnated into a sheet base material and dried to form prepreg, which is laminated, pressed, and molded in one piece. The prepared laminate has characteristics of high-frequency electrical properties, especially low dielectric constant in comparison with epoxy resin and polyimide, and is expected to improve high-speed treatment of large-sized computer.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method for manufacturing a laminate using a resin composition in which a prepolymer having an unsaturated bond in the side chain and a cyclic polybutadiene are uniformly mixed as a structural material. In particular, the present invention provides a laminated material suitable for multilayer printed circuit boards having excellent heat resistance and high frequency electrical properties.

[Background of the invention]

Conventionally, epoxy laminates, polyimide laminates, and the like have been widely used as laminate materials for multilayer printed circuit boards. However, in recent years, with the increase in processing speed of large computers, there has been a demand for multilayer printed circuit boards with excellent high frequency electrical characteristics in order to improve signal propagation speed. However, it is necessary to shorten the propagation delay time and reduce the thickness of the circuit board, which requires a circuit board with a low dielectric constant. Recently, Teflon laminates, butadiene laminates, and the like have been developed as such low dielectric constant materials. However, since the resin composition of the Teflon laminate is a thermoplastic resin, the coefficient of thermal expansion at high temperatures is large, and there are problems with dimensional stability and the like. Furthermore, since there is no suitable solvent for producing Teflon and its melting temperature is extremely high, a lamination method using high-temperature melt pressure bonding is generally used. Therefore, in terms of workability and formability, there are many difficult aspects compared to conventional laminate manufacturing methods, and the required power L6 is required to significantly change the manufacturing method.

Furthermore, when a low molecular weight polybutadiene is used in the butadiene laminate, viscosity remains at the time of preparation of the prepreg sheet, resulting in extremely poor winding work and fR layer workability. To solve this problem, high molecular weight polybutadiene with a softening point above room temperature is used to solve the above problem. However, high molecular weight polybutadiene has the disadvantage that it exhibits almost no fluidity during heat molding. Therefore, a method has been proposed in which the above-mentioned polybutadienes having different molecular weights are used in combination. Although some improvement can be made in this case, the problem of viscosity of the prepreg sheet still remains. The use of cyclic polybutadiene in place of high molecular weight butadiene has also been proposed, but it suffers from the drawbacks of insufficient mechanical strength, heat resistance, etc., which are common problems with butadiene laminates.

[Purpose of the invention]

An object of the present invention is to provide a laminate that has excellent heat resistance and dimensional stability and is suitable as a laminate material for multilayer printed circuit boards. It is an object of the present invention to provide a method for manufacturing a laminate, which is a low dielectric constant laminate material that has particularly excellent high-frequency electrical properties.

[Summary of the invention]

As mentioned above, cyclic polybutanene is a resin composition that provides a laminate with excellent high-frequency electrical properties, but its thermal decomposition initiation temperature is low and there are problems with heat resistance. Furthermore, it has a problem of low mechanical strength when applied to multilayer printed circuit boards.

On the other hand, a general formula having an unsaturated bond in the side chain (in the formula R+, R
(t is a monovalent organic group and a substituent having an unsaturated bond) A compound represented by the following formula can be polymerized into a one-dimensional linear polymer. In addition, by adding a radical polymerization initiator to this prepolymer and heating it, 3
It becomes a heat-waveable resin with a dimensional structure. This resin composition has high mechanical strength and excellent heat resistance. Moreover, this prepolymer is soluble in various solvents, and it is easy to prepare a phenol for impregnating a sheet-like base material. This resin composition can be expected to be used as a structural material in laminate boards as a laminated material for multilayer printed circuit boards.

However, the following problems arise when applied to multilayer printed circuit boards.

Since this heat-waveable resin is extremely brittle and flexible, cracks are likely to occur during adhesive lamination or through-hole drilling. In addition, the adhesive strength with copper foil is weak, and when used for printed circuit boards, problems arise in terms of beer strength with copper.

This heat wave-curable resin is generally more resistant than polyptadiene. Due to the high rate, there is a limit to its application to low dielectric constant multilayer printed circuit boards with excellent high frequency electrical properties.

The present invention uses a resin composition obtained by uniformly mixing such a prepolymer with a cyclic polybutadiene in an arbitrary blending ratio as a structural material of a laminate.

In the present invention, the compound represented by the general formula (1) having an unsaturated bond in the side chain includes CH as RN*R2
=CH2,C0CH=CH! , C0CH=CH! .

COC(CHa l ”CHt, -C00CH=C
Ht, -C00C(CHri=CH!, 0OCCH=
CH,,0OCC (CH=CHt, etc.) In addition, the cyclized butadiene polymer referred to in the present invention is either one obtained by cyclizing polybutadiene or one obtained as a cyclized product from a butadiene monomer. There may be.

[Embodiments of the invention]

Next, an example will be described.

Example 1 A cyclic polybutadiene (Japan Synthetic Rubber) was uniformly mixed into a xylene solution of diallyl phthalate prepolymer (Osaka Soda) to give a solid content of 50%. At this time, the blending ratio of polybutadiene and diallylisophthalate was 5:5. To this was added 6 parts by weight of dicumyl peroxide as a radical polymerization initiator to obtain pheno. The obtained varnish was coated with glass cloth (manufactured by Nittobo, WE-116E, thickness 0
．． 1 Wm) and dried in constant temperature air at 120C for 110 minutes to obtain a prepreg sheet. Next, 10 sheets of the obtained prepreg sheets were stacked at a pressure of 30 Kq f /cr?
L.

Temperature: 1307, further raised to 170C for 30 minutes.

Compression molding was performed for 1 hour. Further, Actacure was performed at 220C for 2 hours to obtain a laminate.

Example 2. Example 1.
A laminate was obtained in a similar manner.

Example 3, Example 1. In the resin composition used in Example 1, the blending ratio of diazi)rein phthalate and cyclic polybutadiene was changed to 7:3. A laminate was obtained in a similar manner.

As a comparative example, a laminate containing diallyl isophthalate alone (
Comparative example 1. ) and a laminate made of cyclic polybutadiene alone (Comparative Example 2.) were prepared in the same manner as in the examples, and comparative studies were conducted on several properties.

As shown in the table, by adding cyclic polybutadiene to the resin composition and performing a crosslinking reaction to create a heat-breakable copolymer, the beer strength and electrical resistivity with copper foil can be greatly improved. I was able to do that.

〔Effect of the invention〕

According to the present invention, a laminate having mechanical strength, heat resistance, and copper beer strength equivalent to that of single-layer poxy laminates and polyimide laminates, which are currently widely used, can be used as a new multilayer printed circuit board laminate material. It is possible to make a manufacturing formula. Furthermore, compared to epoxy and polyimide, the laminate according to the present invention has
It has the characteristics of high frequency electrical properties and special low dielectric constant material.
It is believed that this method can be expected to greatly improve the processing speed of large computers.

As shown in Example 1, it is possible to easily obtain a prepreg sheet, and by combining a laminate obtained by the present invention and a prepreg sheet, a multi-layered sheet can be produced under the same conditions as the method for manufacturing a laminate. It became possible to obtain multilayer printed circuit boards.

Claims (1)

[Claims] 1. General formula having an unsaturated bond in the side chain ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_1 to R_2 are monovalent organic groups and substituents having an unsaturated bond) A radical polymerization initiator is added to a resin composition in which a prepolymer obtained from a compound represented by the formula and a cyclized butadiene polymer are uniformly mixed, and the mixture is impregnated into a sheet-like base material and dried to form a prepreg. , a method for manufacturing a laminate, characterized in that the laminate is laminated and pressurized to integrally form the laminate.