PREPREG, METAL FOIL-CLAD LAMINATED SHEET AND PRINTED WIRING BOARD

摘要

PROBLEM TO BE SOLVED: To provide a prepreg, a metal foil-clad laminated sheet and a printed wiring board in which perforation processing using a drill can be performed with good accuracy and burden to the drill edge is small by using a glass base. SOLUTION: In a prepreg wherein a base material of a glass woven fabric or a glass nonwoven fabric is impregnated with a resin contg. an inorg. filler, filling rate of the inorg. filler is made 40-70 wt.% and the inorg. filler consists of an ingredient of a Mohs hardness of smaller than 5 and an ingredient of a Mohs hardness of at least 5 and the ingredient having a smaller Mohs hardness than 5 is 10-90 wt.%.