PREPREG, LAMINATE AND PRINTED WIRING BOARD

摘要

PROBLEM TO BE SOLVED: To provide a prepreg capable of reducing the roughness of the inner wall of a hole formed by laser processing even by using a nonwoven fabric of an aramid fiber as an insulating base material. SOLUTION: This prepreg is formed by impregnating the nonwoven fabric of the aramid fiber with a resin. The mottle value in a 40μm square tile size of the nonwoven fabric is <=5.0. The concave absent part (a resin-lacking part) in the inner wall of the hole is prevented from being formed when drilling processing by the laser is carried out in a prepreg state and after forming the prepreg into a laminate or a printed wiring board, because the unevenness of the resin and the nonwoven fabric in the prepreg and the laminated plate is reduced as possible by using the nonwoven fabric having high uniformity of the dispersion of the aramid fiber, and good formation.