Assessment of Thermomechanical Damage of Electronic Parts Due to Solder Dipping as a Postmanufacturing Process

Tin whiskering is a concern with tin-rich alloy finishes on electronic part terminations. Solder dipping may be used to replace the original finish with eutectic tin-lead solder for tin-whiskering risk mitigation purposes. However, the solder dipping process may expose electronic parts to thermomechanical damage within the package due to the thermal refinishing profile used during dipping. This paper discusses solder dipping as a refinishing technique and the associated risks from thermomechanical damage. An experimental study was used to assess the possibility of thermomechanical damage on various electronic part-types of different package configurations. Package and die geometries were characterized for all part-types to develop quantitative metrics, which may be used by electronic part users to assess parts for their susceptibility to thermomechanical damage.