Nickel electroforming of 3D microstructure by using BPR100 photoresist mould

Abstract

BPR100 photoresist is a thick negative tone resist with a single-pin film thickness ranging from 40 to 130 ?m. It has been widely applied to plating and etching processes used in Wafer Level Package (WLP). However, its application as mould in electroforming Three Dimensional (3D) microstructure for Micro Electromechanical Systems (MEMS) application has not yet been reported. The process of nickel electroforming of microgears by using BPR100 photoresist mould was thereby studied and is reported in this paper. The electroformed nickel gear was respectively characterised using a Scanning Electron Microscope (SEM) and an Atomic Force Microscope (AFM). Results showed that a pits-free microsgear was achieved with an average surface roughness ranging from 20 to 68 nm and its geometric structure was well shaped. Through this study, it was found possible to electroform 3D microstructure of good quality by using BPR100 photoresist mould.