SRC Forum - Message Replies
Forum: Reliability & Maintainability Questions and Answers
Topic: Reliability & Maintainability Questions and Answers
Topic Posted by: Reliability & Maintainability Forum
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998
Date posted: Wed Apr 27 15:51:13 US/Eastern 2005
Subject: Tin Whiskers
Is anybody here plugged into the Tin Whisker discussions going-on on the RoHS initiative? Pure tin used in solder joints grows whiskers over time and eventually cause shorts between adjacent pins?
Based on the type of package it look possible to predict the failure rate due to tin whiskers for a particular package type. Is it possible to use this info to look at the MTBF of a circuit pack and determine the risk of failure?
Subject: Lead Free Solder
Reply Posted by: bwd
Date Posted: Thu May 12 14:24:27 US/Eastern 2005
The U.S .Air Force, Aeronautical System Center at Wright Patterson AFB, Ohio, has an on going study on lead free solder reliability. The military is concerned with possible whisker growth given the critically of their mission. The commercial manufacturers do not seem to be concerned with this problem according to the articles that are in various technical magazines. Contingency factors can be used to reduce the effect of tin whisker growth. These factors include the use of other lead free substances such as nickel palladium finishes, recoating with lead solder or using a conformal coating to reduce growth.