Engineers can now choose from three S-Class thermal-conductive gap pads from The Bergquist Co., Chanhassen, Minn. ( The 2000S40, 2500S20, and 3000S30 materials have thermal conductivities of 2, 2.4, and 3 W/mK, respectively. They are available from 10 to 125-mil thick and can be delivered as sheets or die cut to match specific components or shapes. When placed atop chips and other circuit-board components, they bridge the gap to the heat sink. The materials are a laminate of a compliant resin with embedded-glass reinforcements on the top layer to resist punctures, shear, and tears. The lower layer is naturally tacky rubber, eliminating the need for additional adhesives that may degrade thermal performance.