Electroplating of nickel on nickel ferrite devices

摘要

This invention is predicated on the discovery by the present applicants that boric acid in conventional nickel plating baths is responsible for excessive lateral growth in the electroplating of nickel on nickel ferrite substrates. While nickel baths without boric acid do not yield acceptable electrodeposits, the boric acid interacts with the ferrite substrate to cause excessive lateral growth. Applicants further discovered that by eliminating the boric acid and adding another acidic plating buffer such as citric acid, one can obtain isotropic nickel plating and produce a wire-bondable surface.