Enhancing the corrosion resistance of Cu/Ni-P/Au electrical contacts by electropolymerized poly(methyl methacrylate)

Cu/Ni-P/Au multi-layer systems are employed as electrical contacts. The Au top-layer is thin and porous. These pores deliver the corrosive media to the under-layer, which induces the corrosion by a galvanic coupling mechanism. Therefore, filling these pores is essential to improve the lifetime of electronic devices. The pores can be sealed by the electrodeposition of poly(methyl methacrylate) that decreased the porosity index (about 97%) and increased the corrosion resistance (about 10 times) of electrical contacts after 10 cycles of electropolymerization. A non-uniform polymeric film, however, was formed at higher number of polymerization cycles ( > 50) that decreased the corrosion resistance.