Circuit board, method for manufacturing same, and high-output module

摘要

A circuit board comprising a patterned first metal layer 14 formed on a ceramic substrate 11, a patterned second metal layer 16 formed on the first metal layer, and a third metal layer 17 formed covering the entire upper surface and side surfaces of the second metal layer and a part of the upper surface of the first metal layer, wherein portions of the first metal layer not covered by the third metal layer are reduced in width by etching. The circuit board has thick-film fine wiring patterns with high bonding strength between the wiring patterns and the substrate and high reliability and enables realization of high-output modules which are small in size and high in performance, by mounting at least one high-output semiconductor element thereon.