초록 ▼

A prepreg comprising a semi-cured thermosetting resin and electrically insulating whiskers or short fibers dispersed in said semi-cured thermosetting resin, and if necessary, a carrier film attached or bound to said prepreg is suitable for producing multilayer printed circuit boards of reduced thinn

A prepreg comprising a semi-cured thermosetting resin and electrically insulating whiskers or short fibers dispersed in said semi-cured thermosetting resin, and if necessary, a carrier film attached or bound to said prepreg is suitable for producing multilayer printed circuit boards of reduced thinness, high wiring density and high connection reliability with high productivity and low production cost.

대표청구항 ▼

[ What is claimed is:] [1.] A prepreg for printed circuit boards comprising a semi-cured thermosetting resin and electrically insulating whiskers or short fibers, except for glass fibers, dispersed in said semi-cured thermosetting resin, said thermosetting resin having no film-forming ability by its

[ What is claimed is:] [1.] A prepreg for printed circuit boards comprising a semi-cured thermosetting resin and electrically insulating whiskers or short fibers, except for glass fibers, dispersed in said semi-cured thermosetting resin, said thermosetting resin having no film-forming ability by itself, yet which has a film-forming ability when having said electrically insulating whiskers or short fibers dispersed therein, said whiskers having an average length of 100 .mu.m or less and said short fibers having an average length of 100 times or less of an average diameter of the short fibers, said average diameter of the short fibers being in a range of 0.1 .mu.m to 15 .mu.m, whereby migration of copper ions along the whiskers or fibers is prevented.