Abhijit Gurav and John Bultitude

Abhijit Gurav
Vice President Ceramic Technology
KEMET Electronics Corporation

 

John Bultitude
Vice President Technical Fellow
KEMET Electronics Corporation

Robust reliability of Class-I ceramic capacitors for power electronics

For applications using wide band gap semiconductors, and for electronics for down-hole drilling and exploration, geothermal energy generation and power electronics, there is a growing need for capacitors that have robust reliability at temperatures of 125°C, 150°C or above. Conventional Class-II type ceramic capacitors (e.g., X7R, X7S) are designed for applications up to 125°C. At temperatures above 125°C, these types of capacitors typically suffer from degradation of reliability performance and severe reduction in capacitance, especially under DC bias conditions. A Class-I C0G dielectric has been developed using Nickel electrodes for high temperature application up to 200°C and beyond. Since it is a paraelectric linear dielectric, these capacitors exhibit highly stable capacitance as a function of temperature and voltage. They possess low loss (DF) and can conduct high RMS currents with a low temperature rise compared to other capacitor solutions. Multi-layer ceramic capacitors (MLCC) made from this material are commercially available for applications up to 200°C, and these also exhibit robust reliability at extreme temperature of 260°C (500 degrees Fahrenheit). They can also be assembled into stacks to achieve higher capacitance in the same footprint. This presentation will report electrical properties and reliability test data on these Class-I C0G ceramic capacitors and stacks at high temperatures.


About the Speakers

Dr. Abhijit Gurav is the Vice President of Ceramic Technology at KEMET Electronics Corporation, Greenville, SC. He has 19 refereed publications and over 80 conference proceeding contributions. His areas of expertise include dielectric and electrode materials, processing and reliability of capacitors, production and characterization of metal and ceramic powders.

Dr. John Bultitude is the Vice President Technical Fellow at KEMET Electronics Corporation, Greenville, SC., and has over 30 years’ experience developing materials for electronics and multilayer ceramic capacitors (MLCC). Current work includes improving MLCC for power applications and packaging these for higher density solutions. He has over 20 active US Patents. .