| abstract |
A prepreg for printed wiring boards that has a low coefficient of thermal expansion in a plane direction, has excellent heat resistance and drilling workability, and, at the same time, can retain a high level of flame retardance includes a base material, a resin composition impregnated into or coated on the base material, and huntite. The resin includes (A) an inorganic filler that is a mixture composed of a hydromagnesite represented by xMgCO 3 .yMg(OH) 2 .zH 2 O wherein x:y:z is 4:1:4, 4:1:5, 4:1:6, 4:1:7, 3:1:3, or 3:1:4; (B) an epoxy resin; and (C) a curing agent. The prepreg can be used to prepare a laminated sheet and a metal foil-laminated sheet. |