The iNEMI Tin Whisker User Group has defined tin whisker mitigation practices and acceptance testing to minimize the exposure of tin whiskers in high-reliability applications.  The group consists of eight iNEMI members from large manufacturers of high-reliability electronic assemblies who annually purchase many millions of dollars of components.  The User Group is very concerned that market pressures will result in market chaos between high- and low-end users demanding the lowest possible costs and/or the highest degree of reliability.  Only by working in concert can the users effectively interact with providers to get the best of both low cost and high reliability.

In 2005, the group released a revised version of its document, Recommendations on Lead-Free Finishes for Components Used in High-Reliability Products (Version 3, May 2005).  In addition the tin whisker acceptance test requirements developed by the iNEMI Tin Whisker User Group have been incorporated into JEDEC standard JESD 201, Environmental Acceptance Requirements for Tin Whisker Susceptibility of Tin and Tin Alloy Surface Finishes, as well as JP002 (see Tin Whisker Modeling Project).  JESD 201, targeted for release in the first quarter of 2006, will be used with the already released test methods document.

Mitigation practices recommended by the User Group include:  use of nickel-palladium or nickel-palladium-gold instead of tin; use of a nickel underlay; annealing/heat treatment (150?C for one hour) of matte tin within a short time after plating; use of a hot dip tin or tin alloy finish rather than plating (SnAgCu is the preferred alloy); and fusing (reflow above 232?C) by the tin plating supplier within a short time after plating.

Additional information:

PRESS RELEASE:  Tin Whisker User Group Publishes Updated Set of Recommendations to Help Reduce Risk of Tin Whiskers (12/15/06)

Recommendations on Lead-Free Finishes for Components Used in High-Reliability Products (Version 4, updated December 1, 2006), iNEMI Tin Whisker User Group

PRESENTATIONS:  iNEMI Tin Whisker Workshop at ECTC (May 30, 2006; San Diego, CA)

PRESS RELEASE:  JEDEC and IPC Release Tin Whisker Acceptance Testing Standard and Mitigation Practices Guideline (5/4/06)

PRESENTATIONS:  iNEMI Tin Whisker Workshop, May 31, 2005; Presented at ECTC; Lake Buena Vista, FL

NOW AVAILABLE from IEEE:  IEEE Transactions on Electronics Packaging Manufacturing: Special Issue on Tin Whiskers.  Download order form.

PRESS RELEASE:  JEDEC Releases Standard for Tin Whisker Testing and iNEMI User Group Updates Lead-Free Surface Finish Guidelines (5/24/05)

Tin Whisker Acceptance Test Requirements (NEMI Tin Whisker User Group, updated July 28, 2004) paper      presentation

JEDEC Standard JESD22A121, "Test Method for Measuring Whisker Growth on Tin and Tin Alloy Surface Finishes," published May 2005 (based on recommendations of the iNEMI Tin Whisker Accelerated Test Project)

Tin Whisker Accelerated Test & Tin Whisker Modeling Projects