Mec Company Ltd.

Toshio Tanimura

Yoshihiro Sakamoto

Minoru Outani

A process for electroplating a surface comprising copper and an insulating material, comprising: applying specific carbon particles or a palladium compound to this surface, microetching the copper to remove the specific carbon particles or the palladium compound, and providing electroplating. The process is characterized by using an aqueous solution comprising 5 to 60 wt % of sulfuric acid, 3 to 35 wt % of hydrogen peroxide, 0.01 to 10 wt % of a phosphonic group-containing amine or a salt thereof, and, optionally, 0.1 to 10 wt % of an amine other than the phosphonic group-containing amine, as a microetching agent. This process can ensure highly reliable electroplating to inner walls of printing wiring board through-holes.

Electroplating process

The invention relates to a process for directly electroplating a conductive metal to the inner walls of through-holes in printed-wiring boards. The process comprises steps of providing an aqueous dispersion containing graphite particles with an average particle diameter of 2 .mu.m or less or carbon black particles with an average particle diameter of 1 .mu.m or less; applying this aqueous dispersion to a surface of a nonconductive surface substrate; dipping the nonconductive surface in a strong acidic aqueous solution with pH 3 or lower to form a layer of said particles; and electroplating using the particle layer as a conductive layer.

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Amagasaki, Japan

Toshio Tanimura