Electronic device with high wettability solder pads

摘要

An electronic device has a layer of high wettability tin-bismuth solder alloy on component leads and substrate pads. The solder is electrodeposited onto copper with an electrodeposition bath containing a zinc salt, although no zinc is co-deposited on the copper. The tin-bismuth layer has a low quantity of oxygen thereby increasing the wettability and decreasing the oxidation at the surface after reflowing.