The use of Complex Alloys to Achieve High Reliability Lead free Solder Joints

摘要

It has been shown in studies that simple SAC based alloys under high delta thermal cycle conditions can be less reliable than traditional tin-lead alloys. This limitation has prevented their widespread adoption for use in high reliability and harsh environments. One approach to overcome this limitation is to increase the creep resistance of the SAC by the addition of further metals to the alloy. The resulting complex alloy displays enhanced thermal cycle resistance when compared with both Sn/Pb and SAC alloys, across all conditions so far tested. In addition to the improved thermal cycle performance the alloy has demonstrated higher operating temperatures and good vibration resistance, making this alloy a good candidate for severe environments such as automotive under hood.