New product development (NPD) is often driven by cost and schedule. In the electronics industry, being first to market with a new technology or product is crucial to its success, and enhanced speed to market is what differentiates world class companies from the rest.
Industry interest in producing thinner and smaller integrated circuit (IC) packages to match the performance of chip scale packages has resulted in the wide application of quad flat no-lead (QFN) components. However, the small-form factor of QFN packages can place solder joints at risk of coefficient of thermal expansion (CTE) mismatch, which can potentially lead to PCB warping and failure. To help mitigate this risk and accurately assess the fatigue life of solder interconnects in QFN packages, a predictive model incorporating the material and geometric parameters that influence solder joint fatigue should be used.
Dr. Natalie Hernandez has been a Product Engineer at DfR Solutions since November 2016. Before, she completed her PhD in Physics at Lehigh University and served as a graduate research assistant working on spectroscopic studies of rare-earth doped wide bandgap semiconductor materials, and has since made the jump to electronics reliability engineering. After 7 months in her new role, here are some of the key takeaways she’s learned about the industry.
When compared to the electronic systems in industries like commercial and industrial equipment, today’s avionics systems face several unique challenges. In addition to operating in rugged environments for long periods of time, they must also satisfy rigorous safety and reliability standards. Most importantly, unlike other industries, they must meet these standards while using commercial-off-the-shelf (COTS) semiconductor devices (logic, memory, etc.) and electronic assemblies that have been designed and qualified for other applications with less rigorous requirements.
Modern electronics have continued in the pattern of Moore’s Law which has decreased transistor size and increased performance. This necessitates development of faster, smaller ICs with greatly reduced power dissipation. However, the increased number of transistors in smaller spaces causes higher power density which can lead to higher failure rates, shorter device lifetimes and unanticipated early device wearout.
Most of the microcircuits used in Aerospace, Defense and High Performance (ADHP) applications today are commercial-off-the-shelf (COTS) components targeted for markets other than ADHP, with required lifetimes that are typically significantly shorter than those of ADHP applications. COTS component manufacturers evaluate their components’ expected lifetimes in the target applications, but provide little or no information for ADHP applications. Thus, it is the responsibility of the ADHP user to conduct the appropriate analyses and, where necessary, mitigate for shorter-than-required lifetimes.
Global avionics is enjoying a period of rapid growth that, when coupled with the relatively low cost of entry into the industry, makes it a very attractive option for new players. This increasingly crowded and competitive landscape makes it even more important to be first to market with new technologies, which can leave less time for reliability testing.
Product performance and reliability are non-negotiables in defense applications. It’s a statement as true now as it was during World War II, when the U.S. military experienced significant malfunctions in aircraft electronics. Then, reliability engineering was just being introduced and focused on metal fatigue and fracture, and solutions were often time-consuming, expensive and ultimately ineffective. These initial efforts, however, spurred a shift to electronics reliability prediction simulation and testing that served as the basis for the Physics of Failure (PoF) approach that is common in many industries today.