New type of paste with enhanced thermal conductivity for modules allows higher power density for same ageing resistance

Power electronics are experiencing a continuous rise in their power densities. As a consequence, thermal management for today's power semiconductors must be integrated as early as their design phase. Only then can reliable cooling be safeguarded over the long term. A particularly important role is assigned to thermal conduction at the link between the component and the heat sink. In these cases, materials are often used that cannot meet the growing requirements. In its search for a remedy, Infineon Technologies AG has incorporated a TIM material solution from Henkel Electronic Materials to now make available a heat conducting compound optimized specifically for the architecture of power semiconductors in modules.

This so called thermal interface material (TIM) greatly reduces the contact resistance between the metal areas on the power semiconductor and the heat sink. On the EconoPACK+ of the new D Series, the contact resistance between the module and heat sink drops by 20 percent. With a high filler content, the material reliably applies its improved properties of thermal contact resistance from the first moment the module is switched on. There is no need for a separate burn in cycle usual on many comparable materials with phase change properties.

The development of the new heat conducting material focused on ease of processing in the form of honeycombs stencil-printed on modules. This prevents air from becoming trapped in the link to the heat sink. Also, the heat conducting material does not contain any substances harmful to health, meeting the requirements under the Directive 2002/95/EC (RoHS). In addition, the TIM is free of silicone and does not conduct electricity.

"With this Henkel TIM, we have the best silicone-free solution for the growing requirements in the thermal management of power semiconductors at our disposal," claims Dr Martin Schulz, responsible Manager for the qualification at the Application Engineering of Infineon Technologies AG. "The paste simplifies the link between the module and the heat sink, optimizes heat transfer, and so extends both the service life and the reliability of the modules." The TIM was developed for use on Infineon modules and is now available for the IGBT EconoPACK+ module series. More details on this heat conducting paste and the module types featuring this can be viewed here: www.infineon.com/TIM.

Provided by Infineon