Method of manufacturing a semiconductor device terminal structure

A semiconductor device si so configured that the circuit patterns formed on both sides of a copper-clad double-sided laminated board are connected to each other by through holes, and IC chips are mounted on the front side, and further, external-connection terminals are provided on the reverse side. In this semiconductor device, the connection terminals are copper core bumps on the land parts of the through holes which are made in diebond patterns. A method of manufacturing semiconductor devices in which copper core bumps are formed on circuit patterns formed on a circuit board, by plating using resist patterns. In this manufacturing method, the parts, where the bumps are to be formed, of the circuit patterns formed by the resist patterns are treated by the same kind of pattern etching as the one used for forming the circuit patterns.