JPS6458531A - Preparation of multilayer printed wiring board - Google Patents

Abstract

PURPOSE:To obtain a multilayer printed wiring board having no resin crack, by setting the cooling speed in the cooling process, which is taken after the heat-curing in a multilayer bonding process in preparing the multilayer printed wiring board using a radical reaction curing type resin, to a specific value range. CONSTITUTION:A radical reaction curing type resin is dissolved in a solvent to impregnate a base material such as glass cloth and the solvent is subsequently removed by drying to prepare a prepreg. A necessary number of the prepregs are held between copper foils and pressed under heating to prepare a copper clad laminate plate for an inner layer. Circuit processing is applied to said laminate plate and a necessary number of the processed laminate plates are superposed through adhesive prepregs to be pressed under heating and holes are further provided to the superposed one and through-hole plating is applied thereto and circuit processing is applied to the outermost layer to obtain a multilayer printed wiring board. Multilayer bonding is usually performed under such a condition that a temp. rising speed is 2-10 deg.C/min, curing temp. is 160-250 deg.C and a curing time is 15-240min. A cooling speed after curing is 0.1-2 deg.C/min. When the cooling speed is faster than 2 deg.C/min, a resin crack is easily generated in the multilayer printed wiring board and, when slower than 0.1 deg.C/min, a manufacturing time becomes long and production efficiency becomes inferior.