Electrostatic discharge (ESD) is not to be taken lightly. Just ask any engineer who has mishandled an RF or microwave transistor or delicate memory chip only to learn later that the device was inadvertently "fried." ESD can plague otherwise well-designed devices and circuits, although not if Dr. Brenda McCaffrey and her crew at White Mountain Labs (www.whitemountainlabs.com) can help it. Based in Phoenix, AZ, the test laboratory specializes in the type of measurements and analysis that helps semiconductor manufacturers find ESD and latch-up (LU) problems in devices and integrated circuits (ICs). The key to success, as Dr. McCaffrey points out, "is to work with a customer early in the design process."
Dr. McCaffrey (see photo) founded White Mountain Labs at the end of 1999 with the belief that the semiconductor industry could benefit from precise measurement and thoughtful analysis of ESD and LU issues. "I was doing standard cell design as well as working on I/O circuits. I realized how easy it was to get bad information and waste time without making improvements on a design," she recalls. With the help of some SBA loans and creative financing from equipment manufacturers, she was able to get started with her vision of providing ESD help through White Mountain Labs. During the past seven years, the company has successfully completed more than 5000 projects for more than 100 semiconductor companies, including overseas firms. The test facility is ISO 17025 accredited for ESD and LU measurements according to standards established by the ESD Association, JEDEC, the US military's MIL standards, and the Automotive Electronics Council (AEC). The facility is certified by the US Defense Supply Center, Columbus (DSCC) as a test laboratory for the US Department of Defense.
White Mountain Labs follows a four-phase program on each project that it calls "The ClearTest Advantage™." The four phases involve educating the customer on the ESD and LU issues pertinent to their product; create project goals and an optimum test approach; implement customer-focused testing; and evaluate the results. The lab relies on a variety of test gear that includes testers from Thermo Fisher Scientific, system-level ESD testers from NoiseKen, a transmission-line-pulse (TLP) tester from Thermo Fisher Scientific (formerly Orxy Instruments), and digitizing oscilloscopes from Tektronix.
The facility performs ESD testing according to the human body model (HBM), and machine model (MM), and the charged device model (CDM). Basically, the HBM which is essentially based on MIL-STD-883, examines interactions between static charges from humans and electronic devices. The MM, with faster risetime waveform than the HBM, studies interactions between charged machines and the devices. The CDM test simulates ESD events in manufacturing environments and features a faster risetime waveform than the other two methods, with much higher peak current.
White Mountain Labs has built a strong reputation by working closely with its customers. While the lab does not determine failures during its ESD testing, it does collect enough data that helps provide insight into what might have happened to cause the failure. Dr. McCaffrey adds, "We have custom software that can help us analyze our test results. By performing TLP measurements, we can even extract device parameters from the test results."