Adhesion strength between conductive paste and lands of printed wiring board, and manufacturing method thereof

摘要

Copper foil lands provided with a through-hole to be filled with a copper paste are provided with ring-formed hollow portions in the periphery of the through-hole where exfoliation between the copper paste and the copper foil lands would hitherto easily occur, whereby a copper plated-through hole both side printed wiring board using a paper-phenol substrate is obtained in which adhesion strength between the copper foil lands and the copper paste has been enhanced.