In situ study the effects of bias and electric field intensity on electrochemical migration behavior of Sn96.5Ag3.0Cu0.5 solder alloy

Abstract

In this work, the influence of bias and electric field intensity on the electrochemical migration of SAC305 solder alloy is investigated using a self-designed in-situ thin electrolyte film device. The results indicate that when the bias is 0.5 V, a compact passivation film forms on the sample surface, effectively inhibiting dendrite growth. When the applied bias reaches 0.75 V, it is observed that specific corrosion products are generated between the two plates, and the occurrence of dendritic growth phenomena is still absent. Dendrite development is observed when a bias voltage of 1 V is applied. Regarding the electrode reactions, when the applied bias falls below 1.5 V, a notable polarization resistance is encountered in the anode reaction. In this case, the cathode reaction primarily entails the process of oxygen reduction. As the applied voltage climbs to 1.5 V, the anodic potential shows an increase, leading to a reduction in the polarization resistance of the anodic process that determines the rate of the electrochemical reaction. At this time, the cathode potential exhibits a comparatively negative value, leading to the progressive occurrence of the hydrogen evolution process. Additionally, the influence mechanism of bias on ECM is also proposed.

Keywords

• SAC305 solder alloy
• Bias
• Electrochemical migration
• Dendrite
• Electrode reaction