Case Study: Bright Tin Whisker Risk in PB-free Connector Applications

Bright tin plating finishes have been widely used in the electronics industry on various hardware applications, including connectors. In recent years, suppliers have gradually transitioned from the use of bright tin-lead plating to bright tin plating in order to comply with EU RoHS regulations. However, electroplated bright tin is known to grow long whiskers (greater than 2mm) in real life applications [1]. This spontaneous growth of whiskers poses a significant reliability risk to today’s electronics. As such, it is imperative to evaluate tin whisker risks and determine Pb-free (Lead-free) readiness in the connector componenet space.

This study is intended to provide a realistic snapshot of tin whisker growth propensity on commercially available connectors under JEDS-201 [2] testing conditions. The parts were chosen to include a sampling of connector attributes, suppliers, and whisker mitigation methodologies.

A summary of test results will evaluate the probability and impact of tin whiskers based upon key connector attributes. Based on the observed trends, the authors will attempt to provide an assessment on tin whisker risk.