Chemical Influences on the Reliability of Complex Assemblies
Authors: Bruno Tolla, Ph.D., Yanrong Shi, Xiang Wei, Hemal Bhasvar Company: Kester Inc. Date Published: 4/14/2015
Abstract: Reliability is one of the key performance drivers of the microelectronics industry today. Miniaturization trends, coupled with a dramatic increase in assembly complexity, increase the risks of in-field failures. Even more concerning to the end-users of electronic components is the difficulty to predict the failure rate of complex assemblies using accelerated tests. Therefore, it is of paramount importance for the end user to develop an in–depth understanding of the failure mechanisms at play, as well as an awareness of the potential contribution of each assembly material to these phenomena. In this paper, we leverage our body of knowledge on flux systems and fluxing mechanisms to bring a chemist’s perspective over reliability failures. After describing the chemical contributions to various failure modes (electrochemical migration, shorts, corrosion, deposits, etc.), we demonstrate how these mechanisms are influenced by the end-usage conditions. We then show how sound formulation principles, paired with a thorough understanding of the application environment, allow the chemists to design robust and reliable chemical systems able to sustain harsh operating conditions. From this perspective, this paper highlights the benefits of a thorough technical partnership between the flux formulator and the end-user to mitigate the risks associated with specific application environments.
Reliability, Electrochemical Migration, Fluxing chemistry, Halogen-free activators, SIR