High-throughput investigation of the coupling effect between adipic acid and NaCl on electrochemical migration behavior of SAC 305 solder alloy

The coupling effect of adipic acid and NaCl on electrochemical migration (ECM) of SAC305 solder alloy for printed circuit boards was studied using a self-designed high-throughput preparation and electrochemical test platform. The promotion effect of 1000 ppm NaCl on anodic dissolution and ion migration steps in the electrochemical migration substantially increased the dendrite formation probability ( P dendrite ) of SAC305 solder alloy. The low P dendrite in 1000 ppm adipic acid was attributed to the enhanced resistance to ion migration step by the formation of complex precipitates. Adding 1 ppm adipic acid into 1000 ppm NaCl could effectively decrease P dendrite due to the co-formation of hydroxide and complex precipitates, while increasing adipic acid concentration (from 10 ppm to 1000 ppm) instead raised P dendrite because hydroxide precipitates could transform into dendrite source at the cathode.