PURPOSE: To improve the adhesive properties, solvent resistance and the resistance to bulge by treating a copper foil with a certain type of silane compound and laminating a polymer at a temperature higher than the glass transition temperature of the polymer on a prepreg core of a polynorbornene copolymer.

CONSTITUTION: A non-cellulose cloth is impregnated with a solution of a polymer obtained by polymerizing a norbornene monomer with various compound, dried until the solvent content becomes about 2.5 wt.% or less, and a prepreg is formed. It is pretreated with a copper foil silane compound, the prepreg is interposed between the two copper foils, and laminated at 1,100 psi or less and 250°C or lower. The obtained printed circuit board has an improved delamination strength, and it has a resistance against a thermal stress at least for 20 sec in a solder bath at 260°C without delamination and bulging of the copper.