The purpose of this paper is to produce and investigate the interfacial reaction between Sn‐3.0Ag‐0.5Cu (SAC305) thin films and Cu substrates by solder reflow at various temperatures and times.
SAC305 thin films were deposited on copper substrates using a thermal evaporation technique. The as‐deposited SAC305/Cu was then reflowed on a hot plate at temperatures of 230, 240, 250 and 260°C for 30 s. In addition, solder reflow was conducted at a constant temperature of 230°C for 5, 10, 15 and 20 s. The microstructure, phase and thickness of the intermetallic compounds (IMCs) formed were determined after cross‐sectional metallographic preparation.
Cu6Sn5 and Cu3Sn were observed at the as‐reflowed SAC305/Cu interfacial region. The IMC thicknesses increased with the higher reflow temperature and longer reflow times.
Up to now, studies on the thin film characteristics of SAC305 lead‐free solder have been very limited. Thus, this paper presents the deposition of SAC305 thin film by a thermal evaporation technique and its characteristics after solder reflow.
