Transphorm’s devices are in use today across a wide range of applications spanning 65 W to 3 kW. Examples include universal, fast charging adapters for smartphones and laptops; rugged, broad industrial power modules; and 1.5 to 3.0 kW Titanium class data center power supplies, which meet the high power efficiency ecodesign requirements mandated by The European Parliament and The Council (ErP: Directive 2009/125/EC).
Transphorm GaN vs. SiC Reliability
Silicon Carbide (SiC) power devices are an alternative power conversion solution and in a later stage of maturation than power GaN solutions. Although SiC offers more than a trillion hours of field operation compared to Transphorm GaN’s 10B hours due to being commercially available longer, recent reports indicate that SiC’s Field Failure FIT rate is 4.1.1 This illustrates the excellent field reliability achieved to date by Transphorm’s GaN with a FIT of < 1.
In-house Reliability = In-field Reliability = Accuracy
Extrinsic Reliability, also referred to as Early Life Failure (ELF) or Infant Mortality, is determined via in-house manufacturer analysis—identifying material, design, and process control defects that may cause parts to fail. Alternatively, Field Failure measures the number of devices that fail in customer systems in production in relation to the total number of parts sold.
When assessing FIT rate, the above two metrics—ELF and Field Failure—are studied. The convergence of these two rates means a semiconductor manufacturer’s internal reliability assessments are accurate; a customer can have confidence in that reported level of device performance.
In January 2019, Transphorm announced a Field Failure FIT of 3.1. Later in 2019, the Field Failure FIT decreased to 2.2. And, today, Transphorm’s Field Failure FIT of < 1 aligns closer to its current ELF FIT rate of 0.61.2
For customers, knowing the ELF statistics of a technology is essential to controlling warranty claims. Transphorm follows the standard industry practice as defined in JEDEC’s JESD74A standard for measuring its Early Life Failure rate. Ensuring conservative results, Transphorm tests its devices to their maximum spike rating and an appropriate use temperature of 85°C. Despite JEDEC qualification requiring Early Life Failure rate testing, only Silicon device manufacturers commonly report it—most GaN and SiC power electronics manufacturers do not.
“To the best of our knowledge, Transphorm is currently the only high voltage GaN semiconductor company to report ELF,” said Ron Barr, Vice President of Quality and Reliability, Transphorm. “We understand that customers require certain information when comparing wide bandgap technologies. So, we aim for transparency here. And accuracy, as we frequently see reliability data being calculated differently or manipulated in uncommon ways yet being reported as the same metric type. Given this trend, our education efforts are focused heavily on explaining the proper methods that must be used to prove business-critical metrics and why.”
Transphorm educates the industry on the most effective Q+R testing methods as well as how to interpret the results to ensure customers have accurate reliability data for business-critical decision making. To learn more, watch Transphorm’s latest video on Reliability Testing: https://bit.ly/3kDnusJ.
Notably, Transphorm’s reliability reports available on its website will be updated by the end of 2020 to include ELF FIT rates of all Gen II and Gen III GaN FETs.
About Transphorm
Transphorm, Inc., a global leader in the GaN revolution, designs and manufactures high performance and high reliability GaN semiconductors for high voltage power conversion applications. Having one of the largest Power GaN IP portfolios of more than 1,000 owned or licensed patents, Transphorm produces the industry’s first JEDEC and AEC-Q101 qualified high voltage GaN semiconductor devices. The Company’s vertically integrated device business model allows for innovation at every development stage: design, fabrication, device, and application support. Transphorm’s innovations are moving power electronics beyond the limitations of silicon to achieve over 99% efficiency, 40% more power density and 20% lower system cost. Transphorm is headquartered in Goleta, California and has manufacturing operations in Goleta and Aizu, Japan. For more information, please visit www.transphormchina.com. Follow us on WeChat @TransphormGaN.
1 “SiC Enabling EV Applications,” Power Electronics News, https://www.powerelectronicsnews.com/sic-enabling-ev-applications/, April 12, 2019.
2 Measured at 520 Volts (80% V(BL)DSS, which is JEDEC standard).
