Anti-sulfidation treatment method of silver alloy bonding wire and application of LED pack silver

With excellent conductivity, ductility, reflectivity and low-cost advantages, silver bonding wire is a more competitive material which can replace the gold wire. It is widely used in display LED and storage fields. However, the key to the application of silver bonding wire is to solve the problem of sulfidation, which causes failure and discoloration. In this paper, a kind of anti-sulfidation film of the silver bonding wire is prepared by using the self-formulated passivation process, with different current densities. The results show that the a smooth and dense passive film covers the surface of the silver bonding wires after the treatment; TEM shows that the thickness of the anti-sulfidation passive film is about 3 nm, which provides excellent anti-sulfidation performance. In addition, the lumen reaches 123.45lm, rising by 1.2% over untreated in LED device; lumen increases by 1.1% compared with unpassivated silver bonding wire after sulfidation test. Therefore, passivation process can solve the application of anti-sulfidation of silver alloy bonding wire.