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JUNE 2025 I SMT007 MAGAZINE 59 " ere are several strategies to mitigate the growth of tin whiskers and their associated risks. " from assembly processes, handling, ther- mal cycling, and mechanical vibrations dur- ing operation can exacerbate the issue. Over time, aging components become more sus- ceptible to whiskers, while surface roughness and defects serve as nucleation sites. Electro- chemical migration, driven by voltage or mois- ture, can further facilitate whisker formation. Understanding these factors is essential for minimizing whisker growth and ensuring the reliability of electronic devices. In contrast to tin pest, which occurs solely in very low temperature environments, tin whis- kers can form at ambient temperatures. Tin whiskers do not need to be airborne to cause damage; they typically grow directly in the environment of the electronic device, where they can create short circuits and disrupt nor- mal function. Studies show that tin whiskers, as illustrated in Figure 2, can reach lengths of 0.025 inches (0.635 mm) on 100% bright tin- plated connector leads stored under typical conditions within just four months. Risks in Electronic Systems Tin whiskers present several risks to elec- tronic systems, especially in critical appli- cations such as aerospace and military tech- nologies. According to NASA, three primary types of failures in space-based systems are associated with tin whiskers: • Short circuits: Tin whiskers can create internal shorts between terminals, termi- nals and headers, cases, and other compo- nents, or between whiskers themselves. • Metal vapor arcs: If a tin whisker vapor- izes, it can generate a highly conductive path capable of carrying a substantial cur- rent. is can cause severe damage to the system, leading to component failure or destruction. • Contamination: Loose tin whiskers can move within the device, potentially reach- ing areas deemed safe from shorts or arcs, causing unintended electrical paths or other issues. Another major concern in aerospace appli- cations is the impact of tin whiskers in high- speed digital circuits, especially those with fre- quencies above 6 GHz. In such environments, whiskers can function as miniature antennas, affecting circuit impedance and causing signal reflections. Moreover, in the vacuum of space, high-power components are particularly vul- nerable. Tin whiskers can become ionized into plasma, capable of conducting hundreds of amperes of current, amplifying the destructive potential of the short circuits they cause. Detection Challenges Given that their median thickness is in the 3–5 micron range (much smaller than a human hair, which is about 75 microns), tin whiskers can be difficult to observe with standard visual inspection methods. To improve the chances of detection, inspectors need to use enhanced lighting techniques, such as right-angle lighting and high magnification. Despite these efforts, the small size and unpredictable growth pat- terns of tin whiskers mean detection remains a significant challenge in ensuring the reliability of electronic components. Mitigation Strategies for Tin Whiskers There are several strategies to mitigate the growth of tin whiskers and their associated risks. A common question is whether confor- mal coatings can prevent tin whiskers. While there is no known conformal coating that can entirely stop a tin whisker from forming, a prop- erly applied coating can reduce the chances of