Dendritic growth on the die under hermetic high temperature operation

Abstract

Electronic units that operate in outdoor environments, such as printed circuit board assemblies (PCBA) in telecom, automotive, industrial, and aerospace applications, can experience a significant amount of humidity exposure over their lifetimes, which might exposes the PCBA to be susceptible to dendritic growth and electrical leakage during operation. However, even in the encapsulated PCBAs operated under high temperature condition, the dendritic growth could still occur and jeopardize the reliability performance of the field operation, which might cause serious financial loss. This study would demonstrate a physics of failure investigation on the electronics component (plastic encapsulated microcircuits) of encapsulated PCBA employed for hermetic high temperature operation. The silver dendritic growth on the die, induced by the excessive silver epoxy die attach material, has been detected and confirmed to be responsible for the current leakage occurring and result in the serious interruption during the field operation.