Robustness of Surface Mount Aluminum Electrolytic Capacitors When Subjected to Pb-Free Reflow

The transition to Pb-free manufacturing, to ensure compliance with RoHS legislation, has resulted in substantial concern over the possibility of unknown reliability issues in product released to customers. One particular area identified has been the observation of bulged or deformed surface mount aluminum liquid electrolyte capacitors subjected to temperatures recommended for Pb-free (SAC Solder Alloy) reflow. Initial reports have simply been limited to observation, with little to no quantitative information available on process guidelines or degradation in capacitor performance. The purpose of this investigation and report was to provide the industry with an initial accounting of the susceptibility of V-chip aluminum electrolytic capacitors to case deformation and assess the potential for potential reliability issues after exposure to Pb-free reflow conditions.