On optimisation of Nickel Electroforming for MEMS applications

This paper presents the details of an optimum nickel electroforming process for MEMS applications. Electrochemical deposition of nickel microstructures in thick resist moulds from a standard process using a sulphamate electrlyte gives most of the time poor quality deposits: non uniform, sometimes with pitting and without adherence on the substrate. As in MEMS devices the features to be electroplated are of micron size (which creates a big disproportion in the surface area between the two electrodes involved in the plating bath), an optimisation of the standard electroplating rocess was developed