Reliability of high temperature solder alternatives

European RoHS directives, enacted in response to concerns about the toxicity of lead, are driving the substitution of Pb-free solders for Pb-containing solders at the component to board level. While European RoHS regulations currently exempt high Pb solders used as component solders and die attaches for automotive and other high temperature applications, there is a strong drive to find Pb-free alternatives for these high temperature electronic applications, as well. This paper presents constitutive and reliability information on one of the widely used high lead solder materials as a baseline, and discusses potential alternative technologies for high temperature solders with the goal of identifying a cost-effective lead-free solder that can be used at temperatures greater than 200 °C.