According to a recent article in National Defense magazine , the U.S. Missile Defense Agency alone has documented $1 billion in catastrophic damage to satellites, missiles, and other defense equipment. The removal of lead from solder and coatings may lead to a dramatic increase in such failures. According to the article, almost 100 percent of DOD electronics have tin-lead components. Even though the United States does not mandate lead-free solder, the Pentagon and its contractors source electronics from a global supply chain, and many suppliers are based in Europe or other countries that are moving toward European standards, such as Japan and South Korea. In order to meet quality standards, DOD contractors will need to modify any lead-free commercial and COTS components, which will increase costs. The article estimates cost increases from 50 to 200 percent. The article quotes an industry source as stating that lead-free assemblies performed poorly when compared to systems that utilized tin-lead solder, meaning that performance may degrade even as costs increase.
The "tin whiskers" phenomenon is not new. NASA reports that it was first observed in the 1940s and 1950s and has been under study since that time. Although the whisker-forming mechanism is still not well understood, NASA recommends use of a conformal coat of Arathane 5750 may reduce the risk of electrical short circuits resulting from tin whiskers. It will be important for NASA and DOD contractors to address this issue, by both evaluating their suppliers for the use of lead-free solder and coatings and by developing appropriate mitigation strategies.
| < Prev | Next > |
|---|
