Question posed by the Moderator to Dongkai Shangguan:
Lead-free solders are continually being developed with improved performance, but adoption for high-end applications is still limited. What are the critical needs and realistic expectations for lead-free solder technologies for these applications?

Dr. Shangguan responded: For high-end applications, I believe a key consideration is reliability. Some of the concerns from the user community are that there has not been enough history of application of lead-free solder to give them sufficient confidence in the reliability. Therefore, I think we need to accelerate our start in research on the reliability of lead-free solder under a variety of conditions, including prolonged thermocycling, including a combination of loading conditions.

Also, a fundamental understanding of the acceleration mechanism of the lead-free solder tin-silver-copper solder alloy would be very, very essential to the design of appropriate acceleration tests for high-end applications. With good understanding of the acceleration mechanism reflected in the design of the accelerated reliability tests, reliable data can be accumulated to increase the confidence of the high-end user community. I believe that will facilitate and accelerate the adoption of lead-free solder in the high-end product.