Fabrication of Cu-based carbon nanofiber composite film applied in MEMS contactor

A novel method for fabricating Cu-based carbon nanofiber (CNF) composite film as contact electrode of MEMS electromagnetic relay is presented in this paper. All the electroplating equipments and electroplating solution including CNFs are all placed in ultrasonic agitation environment during the whole electroplating process to avoid the agglomerating of CNFs on the surface of the MEMS contactor. The tested results shows that CNFs were distributed evenly and few spheric Cu- based CNF particles were discovered. The composition of the electroplating solution is optimized by many experiments. When the concentration of the CNFs is up to the 4g/L, the maximum hardness (208 HV) of Cu-based CNF composite film is achieved with the improvement of 50.9% compared with the one of the pure copper. When the MEMS contactor with Cu-based CNF composite film is applied in an electromagnetic microrelay, the contact resistance is reduced to 200~300m .