Chemical reducing solution for copper oxide

摘要

A chemical reducing solution obtained by using an alkali boron hydride as a reductant and adding thereto a water-soluble, polyoxyethylene chain-containing organic compound having a molecular weight of 200 or above molecule as an additive has merits in that it can reduce copper oxide to metallic copper while maintaining the needle-like form of copper oxide as completely as possible and the reduction can be completed in a short period of time by a simple procedure, so that the chemical reducing solution is successfully usable in a process for producing a multi-layer printed circuit board.