Patent ID: 7566501

Claim:
A process for producing a printed wiring board, which comprises: gluing a prepreg to a metal foil surface and hot pressing the prepreg and the metal foil surface to produce a laminate board, and forming a circuit on an outer layer of the laminate board to yield a printed wiring board; wherein said prepreg is manufactured by impregnating a reinforcing material with an epoxy resin composition followed by drying and semi-curing the composition to B-stage; said epoxy resin composition comprising an epoxy resin, a phenol novolac resin, a curing accelerator and a silica filler; wherein said silica filler is a silica filler which has a shape having at least two planes, and has an average particle diameter between 0.3 pin and 10 μm and a relative surface area between 8 m 2 /g and 30 m 2 /g.