Investigation of Factors That Influence Creep Corrosion on Printed Circuit Boards - Part 2
Authors: Haley Fu, Cherie Chen, Prabjit Singh, Jing Zhang, Anil Kurella, Xu Chen, Xiaodong Jiang, Jennifer Burlingame, and Simon Lee Company: iNEMI, IST-Integrated Service Technology, Inc., IBM Corporation, Intel Corporation, Alcatel-Lucent, Alcatel Shanghai Bell, Cisco Systems, and The Dow Chemical Company Date Published: 10/14/2012
Abstract: Creep corrosion of electronic assemblies is a growing problem. Commonly seen in harsh environments, the failures result from the formation of copper sulfide films on Printed Circuit Board (PCB) assemblies in short period of time. The iNEMI Creep Corrosion Group working on understanding this issue has recently communicated the feasibility of simulating these corrosion signatures on electronic assemblies using a modified Mixed Flow Gas (MFG) test method. This paper is a continuation of that work wherein the sensitivities of various PCB surface finishes, design features, process parameters, and flux materials to promote corrosion were studied by simulating corrosive environments in a MFG chamber. Of the four different surface finishes studied Pb-free HASL was least prone to corrosion. Results from the electrical resistance measurements coupled with detailed material analysis of the corrosion products will be presented in this paper.