+ View the NASA Portal NEPP Website Search   Powered By Google Your Path: Home » Packaging » Packaging Experts   Packaging Publications Index   Packaging Publications By Area of Emphasis   Packaging Links Packaging Experts   Focused Packaging Issues Portals   Search         BACK to Publication List Video: Known Problems with the Use of Pure Tin Coatings - Questions File Name: Leidecker_Questions_56k.rm | Date Submitted: 10/04/01   File Size: 720KB Document Author Henning Leidecker - henning.w.leidecker@nasa.gov Goddard Space Flight Center Phone: 301 286-9180 | FAX: 301 286-1695 [Additional User Information] Download "Video: Known Problems with the Use of Pure Tin Coatings - Questions" (720KB) Now.   Description: NEPP Virtual Conference   Abstract: Pure tin coatings grow whiskers, sometimes promptly, sometimes after a delay of several years. These have shorted electrical circuits, introducing anomalies and even failures. The risk of anomalies and failures is increasing as the typical bus voltages and available currents decreases. Also, spacecraft are subject to the occurance of a whisker-induced vacuum metal arc which sustains hundreds of amperes, until there is fatal damage. Finally, operation at temperatures below about 20 °C allows the transformation of tin from its metallic phase into a semiconducting phase that is both brittle and relatively non-conducting.   Related Project(s): EPAC (Electronic Packaging)   Related Area(s) of Emphasis: Lead Free Electronics Development of Innovative Qualification Methods     NEPP Program Manager: Michael J. Sampson Responsible NASA Official: Michael J. Sampson Webmaster: Carl M. Szabo, Jr.       Last Updated: January 10, 2002