FLAME-RETARDANT EPOXY RESIN COMPOSITION FOR PRINTED CIRCUIT BOARD, AND PREPREG AND METAL-CLAD LAMINATE PREPARED THEREFROM

摘要

PROBLEM TO BE SOLVED: To provide a flame-retardant epoxy resin compsn. which, when used as a material of printed circuit boards or multilayered circuit boards, exhibits enhanced heat resistance and excellent adhesiveness and insulation reliability and to provide a prepreg and a metal-clad laminate prepd. from the compsn. SOLUTION: This compsn. contains, as essential ingredients, (a) an epoxy resin contg. a glycidyl ether of a polycondensate of bisphenol A or F and formaldehyde, (b) a polycondensate of bisphenol A and formaldehyde, (c) a halogenated bisphenol A as a flame retardant, and (d) a cure accelerator, the amt. of the halogenated bisphenol A contained being 45 wt.% or lower of the total solid resin content. The metal-clad laminate is prepd. by preparing a varnish from the compsn., impregnating a substrate with the varnish followed by drying to give a prepreg, and laminating a metal foil to at least one side of at least one sheet of the prepreg under heating and pressure.