Intermittent Connector Failures

Aravind Munukutla and Anil Kurella
Intel Corporation, Hillsboro, OR, USA

Connectors are an integral part of any electronic assembly. As a result their reliability is a critical aspect for proper functioning of electronic systems, be it a mobile phone or a high end telecom server. There are a number of papers published on electrical connector failures that focus primarily on contact interface plating issues. From our failure analysis experiences we have identified numerous factors beyond materials or plating issues that can contribute to intermittent failures. Using complex electrical analytical techniques the failures were isolated to specific signals which were then subjected to in depth material analysis.

Although in most cases the predominant failure mechanism is contact area corrosion the root causes have ranged from incoming raw material issues to mother board assembly process issues to end customer usage environments. This paper discusses findings from such case studies. It also discusses the corrective actions that were put in place for many of these cases.

Connector reliability is extremely important to all electronic assemblies due to the constant changes in end customer usage conditions, and the heavy competition for better and cheaper products. As described in the four case studies which deal with connector raw material properties, damage induced contact area corrosion, corrosion due to plating issues and contamination based failures, intermittent connector failures are not necessarily related to contact area corrosion just due to plating issues.

In all the four cases we observe that there is degradation of contact resistance at the mating surfaces due to various reasons. In order to resolve the issue and take proper corrective actions it is critical to understand and take into consideration materials, process, handling & integration issues as well as customer usage conditions.