High-resolution wet etching technology of thick electroless nickel alloy film for MEMS devices and packaging

In this paper, we present a high-resolution wet etching technology of 1.5 μm-thick electroless nickel alloy film. The minimum feature size was successfully reduced to about 10 μm. The developed etching technology is well compatible to conventional micro-electro-mechanical systems (MEMS) processes, and has been successfully utilized on the 4-inch wafer as well. It could be expected more practical application of electroless nickel alloy film in not only MEMS but also electronic packaging.