NONWOVEN FOR ELECTRIC INSULATION, PREPREG AND LAMINATED PLATE

摘要

PROBLEM TO BE SOLVED: To reduce the difference in hole diameters when carrying out a hole- opening processing by irradiating laser light on a prepreg comprising a nonwoven fabric consisting essentially of para-type aramid fiber as a base material, and further to reduce the difference of size changes caused by the heating of a laminated plate or a print circuit board. SOLUTION: This nonwoven fabric is the one consisting essentially of chopped fibers of a para-type aramid fiber, and obtained by binding the fibers to each other. The nonwoven fabric to be used as the chopped fibers of the para-type aramid fiber is obtained by carrying out papermaking of a mixture of (a) a poly-p-phenylene-3,4-diphenyl ether terephthalamide fiber with (b) a poly-p- phenyleneterephthalamide fiber. The weight ratio of both components (a)/(b) is (10/90)-(90/10), preferably (30/70)-(70/30).