Microwave Journal

AEM's tin whisker mitigation process assures surface-mount component reliability

May 29, 2013

AEM Inc. announces a hirel-qualified Sn/Pb (tin/lead) conversion process designed to mitigate the formation of tin whiskers in surface-mount components. The AEM process eliminates potential damage to sensitive electronic devices caused by conventional hot-solder dippingwhile ensuring that converted component terminations con­tain a minimum of 5 percent Pb as verified by SEM/EDS and XRF inspection methods. AEM’s Sn/Pb conversion process is best suited for chip-scale passive components, including capacitors, inductors, resistors, ferrite chip beads, fuses, resistor arrays, capacitor arrays, bead arrays and many molded body passive and active surface-mount component types. This process includes 100 percent adherence to visual and mechanical inspections per applicable EIA guidelines, including sample solderability, leach resistance, terminal strength, and destructive physical analysis (DPA) screening.

“Components terminated entirely with a tin solder are susceptible to unpredictable whisker growth,” said AEM’s Marketing Director, Scott Sentz. “And for ultra-high-reliability applications, RoHS-compliant devices must be converted back to tin/lead terminations. Components with external leads can be hot-solder-dipped, but this is not the case for chip-style components due to thermal shock concerns.”

 While AEM’s Sn/Pb conversion process is applicable to most multi-layer, chip-style components, other component types may be processed subject to an AEM pre-evaluation and component construction analysis, which is typically performed by AEM at no cost to the customer. Optional component up-screening (e.g., up-rating commercial components for use in military, aerospace or medical applications) and QCI can be performed by AEM’s MIL-STD-202 compliant and AS9100 certified lab. Converted and up-screened components are warranted as AEM products.