Influence of bismuth on the solidification of tin copper lead-free solder alloy

Lead-based solder alloy has been used for a long time as solder material in electronic industry. However, its usage in electronic industry has been restricted due to its toxicity to human health and negative impact on the environmental. Lead-free solder alloy was developed to replace the lead-based solder alloy. The properties of this lead-free solder alloy must be the same or much better than the lead-based solder alloy. In this research, the influence of bismuth (Bi) as alloying element on the solidification of tin copper (SnCu) lead-free solder alloy were studied and investigated. The SnCu+xBi where x = 1.5, 3, 4.5 6 wt.% lead-free solder alloy were fabricated by using casting process. To study the wettability, formation of intermetallic compound (IMC) layer, microstructure and hardness, the SnCu+xBi lead-free solder alloy were reflow on Cu substrate by using reflow oven. Overall, addition of Bi as alloying element does influence the characteristics and properties of SnCu lead-free solder alloy in an effort to replace the lead-based solder alloy in electronic industry