Up Time Magazine - February/March 2009 - (Page 44) • Differences in thermal expansion characteristics between the substrate and the plating material. • Microscopic damage to the plating or the substrate material caused by handling or application of test probes etc. “Whisker growth may begin soon after plating. However, initiation of growth may also take years. The unpredictable nature of whisker incubation and subsequent growth is of particular concern to systems requiring long term, reliable operation.”1 management, the problem will unfold something like this: Condition-Based Maintenance Condition-based maintenance relies on the existence of a usable and reasonably consistent P-F interval. Clearly, from the data available, this is not the case for whiskers and is unlikely to be either applicable or effective. tion/calibration and testing with probes. plus the high proportion of perfectly good equipment that would be scrapped, make this option unlikely to prove viable. Failure-Finding Failure-finding is associated with hidden failures. Here is a real problem – with no way to tell how a circuit might fail with short circuits induced by tin whiskers, it is difficult to assess the risk of a hidden failure occurring. If the MTBF for tin whisker failures can be established, it should be possible to identify a test interval that will reduce the risk to a tolerable level or an expected availability. However, again, we currently lack data to make that decision with any confidence. Testing for loss of hidden function will tell us whether the system is functional or not at the time of the test, but nothing more. Scheduled Restoration / Discard Frequencies for restoration or discard rely on an age at which there is a rapid increase in the conditional probability of failure. Although, theoretically, a discard task may be applicable, it is unlikely to be effective and may remove a good circuit board that has no whisker development and replace it with a new one that soon will have. Additional risks of inducing failures due to incorrect installa- What Can We Do to Manage Tin Whiskers? Managing failures caused by tin whiskers is a challenge for maintenance professionals because of its unpredictable nature. Using RCM principles to examine the options for failure Maximum Impact Simulcast Leadership that Inspires MAY 8, 2009 Imagine joining with 500 other satellite locations throughout North America with a single vision: inspiring change . The Maximum Impact Simulcast will deliver an unmatched day of leadership training. KEVIN CARROLL Highly-acclaimed author, Founder of Kevin Carroll Katalyst, LLC and former Nike creative LINDA KAPLAN THALER CEO & Chief Creative Of cer of the Kaplan Thaler Group and author of The Power of Nice AL WE ISS President of Worldwide Operations for Walt Disney Parks and Resorts JOHN C. MAXWE LL Best-selling author, speaker and leadership thought leader TONY B LAIR Former Prime Minister of the United Kingdom JACK NICKLAUS Winner of a record 18 major golf championships and voted Sports Illustrated’s Individual Male Athlete of the Century B ILL GEOR GE Harvard business professor, former Medtronic CEO and author of True North: Discover Your Authentic Leadership LIZ MURRAY Inspirational speaker, “Homeless to Harvard” MARK S ANB ORN Best-selling author of The Fred Factor and President of Sanborn & Associates, Inc. ERNIE JOHNSON Professional sports announcer and host of TNT’ s Emmy awardwinning Inside the NBA Don’t miss this one-day leadership event. For local sponsorship or ticket information, please contact: www.maintenanceconference.com (888) 575 1245 44 february/march 2009 http://www.maintenanceconference.com http://www.reliabilityweb.com http://www.maintenanceconference.com
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