Application of thermal interface materials in power modules to enhance thermal performance and reliability

Abstract: In power electronics applications thermal interface materials (TIM) are placed between the power devices and heatsink in order to provide good thermal contact. They have a crucial role in ever demanding applications where an increased lifetime is required due to high power densities and elevated temperatures.
This tutorial will deep dive into the TIM topic to cover its theoretical and practical aspects. After a brief introduction of the purpose of TIM, it will examine different types of material and applications, paste thickness and heatsink specification. It will also present selection criteria for TIM in combination with power modules. The measurement of effective thermal paste thickness, evaluation and qualification of TIM and estimating its thermal resistance will be discussed. This also includes the selection of the optimal thickness and print pattern. The tutorial will also explain failure modes and lifetime aspects associated with TIM. Concrete examples will be given to highlight available TIM materials in the market and their applications in industry standard modules. Latest trends and pre-applied thermal interface materials for power modules are also discussed in length, including the performance difference between different materials in combination with power module packaging technologies.

Kevork Haddad earned his Master of Applied Science degree in Electrical Engineering from Concordia University, Montreal, Canada, in 1997. He joined SEMIKRON, Inc. in 2000. From 2008 to 2014 he was Applications Engineering Manager and head of new Product Development Manager. He is currently the Product Marketing Manager for North America and he is also actively involved in new technologies (i.e. SiC, customized modules and Multilevel Inverters). He holds several patents in the power electronics area and has published technical papers in various conferences. His research interests include Compound Semiconductors (SiC), Multilevel converters, Renewable Energy Systems, Uninterruptible Power Supply Systems, Energy Storage Systems, Control of Power Electronic Converters and Packaging Technologies. He is a member of IEEE and Power Electronics Society.

Paul Drexhage graduated from the Rochester Institute of Technology with a Bachelor’s degree in Electrical Engineering in 2006. After an internship at AC Tech (Lenze Americas), he joined SEMIKRON in 2007 as a design engineer for power converters ranging from 10 kW to 1 MW. He currently serves as Applications Manager and is responsible for technical support for North America, including troubleshooting existing systems and supporting new customer designs.

Bernhard Eichler owns a diploma in electrical engineering and an M.B.A. He worked as an R&D engineer and product manager for renewable energy converters at Siemens before he joined SEMIKRON in 2016. At SEMIKRON Bernhard is responsible as product manager for medium voltage modules as well as for the international product marketing activities for the markets solar, wind energy and traction.