PolarChip SF3000 is a soft silicone-free, thermally conductive material suited for filling air gaps between heat-generating devices on PCBs. The highly compressible thermal gap pad is a fluoropolymer composite that consists of an expanded polytetrafluoroethylene matrix filled with boron nitride particles. The reinforcing nature of the ePTFE matrix results in a composite that is said to be physically robust, easy to handle and does not require additional reinforcement. Produced in continuous rolls with a pressure sensitive adhesive on one side. Comes in sheets or rolls of precision die-cut parts suitable for high-volume automation assembly. 

W.L. Gore & Associates, www.gore.com