Patent ID: 8603624

Claim:
A prepreg obtained by impregnating a woven fabric base with a thermosetting resin composition, wherein the thermosetting resin composition contains 80 to 200 volume parts of an inorganic filler per 100 volume parts of a thermosetting resin, and the inorganic filler contains (A) gibbsite aluminum hydroxide particles having an average particle diameter (D 50 ) of 2 to 15 μm, (B) at least one inorganic component selected from the group consisting of boehmite particles having an average particle diameter (D 50 ) of 2 to 15 μm and inorganic particles that have an average particle diameter (D 50 ) of 2 to 15 μm and that contain crystal water having a release initiation temperature of 400° C. or higher or contain no crystal water, and (C) aluminum oxide particles having an average particle diameter (D 50 ) of 1.5 μm or smaller, the compounded ratio (volume ratio) of the gibbsite aluminum hydroxide particles (A), the at least one inorganic component (B) selected from the group consisting of the boehmite particles and the inorganic particles, and the aluminum oxide particles (C) being 1:0.1 to 2.5:0.1 to 1.