Method of making multilayer substrate

Abstract

A method of making a multilayer substrate comprising: (a) providing an interlayer circuit board having conductor circuits thereon; (b) forming a dielectric layer on the interlayer circuit board; (c) mechanical drilling (or laser drilling) through the dielectric layer to the conductor circuits at predetermined positions thereof so as to form blind-vias; (d) electrolessly plating a conductive layer on the surface of the dielectric layer and the blind-vias; (e) forming an etch resist on the conductive layer, followed by formation of outer conductor circuits on the conductive layer by selectively etching; and (f) removing the etching resist. Since the blind-vias of the present invention are formed by drilling instead of photosensitive polymer technology, the processing steps are minimized thereby significantly improving the production efficiency. Furthermore, since the mechanical drilling (or laser drilling) has better accuracy, the blind-vias can be formed with better accuracy.

Dependencies are inferred from the claim text.