New developments for a no-pump-out high-performance thermal grease

The industry trend toward reduced feature size and faster operating speed has generated demand for higher powered devices. The increased power and reduced overall area creates higher thermal loads for the package. This has led to the need for new thermal materials with high thermal conductivity. High-performance thermal interface greases, gels, and adhesives significantly improve the transmission of the heat generated by the high power densities out of the system. Thermal greases generally have higher thermal conductivity than gels or adhesives with similar fillers. Unfortunately, greases typically pump out and separate during use. Additionally, some applications that require higher thermal conductivity materials cannot go through a cure profile normally used for non-grease thermal interface materials (TIMs). Use of integrated heat spreaders avoids some of the processing restrictions placed on board-level thermal solutions, but many applications - particularly in mobile electronics - have little space or have significant weight constraints that interfere with the use of a built-in heat spreader. A new 4 W/mK silicone thermal grease with dramatic property improvements has been developed with significant resistance to in-package bleed-out or pump-out, eliminating the reliability problem most commonly encountered with traditional thermal greases.