Benzaldehyde derivatives on tin electroplating as corrosion resistance for fabricating copper circuit

Abstract

Electrodeposited tin is a crucial corrosion-resistant metal to protect electronic interconnection and copper circuits in the manufacturing process of electronic products. The corrosion-resistant properties of electrodeposited tin can be improved with the addition of additives in electrodeposition. Three benzaldehyde derivatives including vanillin, ethyl vanillin, and veratraldehyde as brighteners were investigated for tin electrodeposition. Computational and experimental analyses were conducted to investigate the relationship between coating properties and the chemical factors including the molecular structure, adsorption process, and electrochemical behavior of the brighteners. The computational work demonstrated that all three brighteners could hold high reactivity and spontaneously absorb on the tin surface. The results of linear sweep voltammetry tests (LSV) illustrated that all three brighteners effectively increased the cathode polarization but ethyl vanillin exhibited the best inhibiting performance in the tin deposition. Besides, the adsorption behavior of brighteners on the tin layer also affected the grain morphology and preferred growth orientation of the crystal surface. The corrosion rate and side erosion results both indicated that ethyl vanillin could benefit to form a tin coating with good corrosion performance to meet the requirement of copper circuit fabrication of printed circuit board.

Keywords

• tin electroplating
• brightener
• adsorption behavior
• corrosion
• copper circuits