Technical Library | 2015-10-22 17:37:28.0
The objective of this study is to evaluate conformal coatings for mitigation of tin whisker growth. The conformal coatings chosen for the experiment are acrylic, polyurethane and parylene. Also included in this paper are tin whisker inspection results of tin-plated braiding and wire that was exposed to an environment of 50°C with 50% relative humidity for over five years.
Technical Library | 2015-11-19 18:15:07.0
The move to lead free (Pb-free) electronics by the commercial industry has resulted in an increasing number of ball grid array components (BGAs) which are only available with Pb-free solder balls. The reliability of these devices is not well established when assembled using a standard tin-lead (SnPb) solder paste and reflow profile, known as a backward compatible process. Previous studies in processing mixed alloy solder joints have demonstrated the importance of using a reflow temperature high enough to achieve complete mixing of the SnPb solder paste with the Pb-free solder ball. Research has indicated that complete mixing can occur below the melting point of the Pb-free alloy and is dependent on a number of factors including solder ball composition, solder ball to solder paste ratio, and peak reflow times and temperatures. Increasing the lead content in the system enables full mixing of the solder joint with a reduced peak reflow temperature, however, previous research is conflicting regarding the effect that lead percentage has on solder joint reliability in this mixed alloy solder joint.
SMTnet Express, October 22, 2015, Subscribers: 23,631, Members: Companies: 14,705, Users: 39,186 Tin Whisker Risk Management by Conformal Coating Linda Woody, William Fox; Lockheed Martin Missiles and Fire Control; Lockheed Martin Corporation
SMTnet Express, November 19, 2015, Subscribers: 23,763, Members: Companies: 14,760, Users: 39,366 HALT Testing of Backward Soldered BGAs on a Military Product B. Gumpert, B. Fox, L. Woody; Lockheed Martin Corporation The move to lead free (Pb
