Connector Reliability: Tradeoff Between Surface Plating and Mechanical Solutions
Authors: Karumbu Meyyappan, Alan McAllister, Anil Kurella, Balu Pathangey Company: Intel Corporation Date Published: 9/28/2014
Abstract: Separable connections, like CPU substrates and sockets, are commonly plated with gold for optimum electrical properties. There is a general acceptance that higher gold thickness translates to improved corrosion resistance and improved reliability performance. However, increased gold thickness drives higher cost due to increasing cost of gold. The connector industry has been constantly looking for cheaper, yet reliable alternate plating material. Understanding the in-field usage, failure mechanism and failure drivers are key to enabling cheaper, alternate plating material. To fundamentally study the failure mechanism at the area of interest, an innovative test fixture was designed. The test samples were exposed to a mixture of corrosive gases (Cl2, SO2, H2S, NO2) at high humidity. The miniature test fixture with its in-situ resistance monitoring setup was used to study the effects of mechanical force and shielding (reduced gas exchange) in a very controlled manner. The experimental findings will be related to risks expected at various in-field usage conditions (infrequently mated vs. frequently mated connectors). This information will provide guidance to the connector designers on optimizing the gold thickness and the required mechanical force for stable electrical performance.