PURPOSE: To depress the moisture absorption of the resin in the surface of a resin-impregnated base material and to obtain the material for printed wiring board of good quality, by carrying out the processes from impregnating a resin in a base material to form a laminated body under a specified steam pressure.
CONSTITUTION: To obtain continuously the material for a printed wiring board by impregnating a resin in a continuously supplied long belt-like base material, by forming continuously a laminated body containing at least one resin- impregnated base material thereby obtained and by curing the resin contained in the laminated body, the processes from impregnating the resin in the base material to forming the laminated body are operated under the atmosphere of steam pressure being lower than 20mmHg. To do so, for example, it can be realized by operating the processes from impregnating the resin in the base material to forming the laminated body in a chamber of ambient temperature and pressure, where the steam pressure is lower than 30mmHg. It is allowable to form the laminated body by laminating a metal foil such as copper foil at least on one surface (one or both surfaces) of the resin-impregnated base material and to obtain thereby the material for the printed wiring board.
OKADA SHIGEHIRO
KUNITOMI TETSUO
MITO TETSUO
| JPS55144159A | 1980-11-10 |
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