Application Note AN1010 Cooling Critical Components Introduction Design engineers are routinely faced with applications that require special thermal management attention. A CTS customer recently solved its thermal concern by selecting a CTS/IERC extruded aluminum “Peel and Stick” product to cool a BCM8320 fabric interface chip. Applications for Peel and Stick Heat Sinks Heat is a by-product driven by higher performance and faster speeds of data processing. CTS/IERC extruded aluminum heat sinks are available with a pre-applied, double-sided thermally conductive adhesive tape. This adhesive provides a convenient and cost-saving solution for many thermal management challenges. Figure 1 shows a half-slot module, with a CTS/IERC BDN18-6CB/A01 heat sink attached to a BCM8320 fabric interface chip, integrated into a service router. The customer selected the easy-to-apply BDN18-6CB/A01, which can dissipate 2.8°C/Watt in forced convection, for its Ethernet service switch and service router. To maximize cooling, the customer chose a larger heat sink (1.81” x 1.81”) to fit over the smaller device package (1.38” x 1.38”). Figure 2 illustrates the Peel and Stick product, which has a footprint range from 0.91” x 0.91” to 2.11” x 2.11” and fin heights of .355”, .555” and .605”. Figure 1: Service Router with Ethernet Service Switch Half-Slot Module with CTS/IERC BDN18-6CB/A01 Heat Sink Figure 2: Extruded Aluminum Adhesive Peel and Stick Heat Sinks Characteristics of Peel and Stick Heat Sinks Applicable for BGA, PDA, PLCC, and QFP packages with consistent and repeatable performance Omnidirectional Thermally optimized pin fin Excellent mechanical bond (adhesive shear strength at 100°C is 36psi) Apply by peeling off the release liner and pressing onto the component Reduces assembly costs and time: o No stencil, no dispenser, no curing equipment/agent, no ventilation equipment/workstation, no requirement for tight process control, and no chemical-waste disposal control required o Minimal set-up time, no cure time, and no clean-up time CTS Electronic Components www.ctscorp.com Page 1 Application Note June 06 AN1010 Extruded Aluminum – Peel and Stick Heat Sink Specifications Standard Peel and Stick Heat Sink part numbers are shown in Table 1. Customers with a different mechanical footprint or special thermal requirements are encouraged to contact CTS/IERC for a custom solution. Table 1: Extruded Aluminum Peel and Stick Heat Sinks Heat Sink Part Number*** BDN09-3CB/A01 BDN09-6CB/A01 BDN10-3CB/A01 BDN10-5CB/A01 BDN11-3CB/A01 Thermal Resistance Case To Ambient* °C/Watt Width Length 0.91 0.91 1.01 1.01 Height Fin Matrix 0.355 0.605 0.355 0.555 0.355 7x7 4x4 7x7 5x5 8x8 Natural Convection** Forced Convection @ 400 LFPM 26.9 24.5 26.4 20.8 20.9 9.6 7.7 8.0 6.3 7.2 1.11 1.11 BDN11-6CB/A01 0.605 5x5 18.5 BDN12-3CB/A01 0.355 9x9 19.6 1.21 1.21 BDN12-5CB/A01 0.555 6x6 16.5 BDN13-3CB/A01 0.355 9x9 16.1 1.31 1.31 BDN13-5CB/A01 0.555 6x6 14.9 BDN14-3CB/A01 0.355 10x10 16.2 1.41 1.41 BDN14-6CB/A01 0.605 6x6 13.1 BDN15-3CB/A01 0.355 11x11 15.1 1.51 1.51 BDN15-5CB/A01 0.555 7x7 11.9 BDN16-3CB/A01 0.355 11x11 13.5 1.61 1.61 BDN16-6CB/A01 0.605 7x7 10.6 BDN17-3CB/A01 0.355 13x13 11.5 1.71 1.71 BDN17-5CB/A01 0.555 8x8 9.5 BDN18-3CB/A01 0.355 13x13 10.8 1.81 1.81 BDN18-6CB/A01 0.605 8x8 8.1 BDN19-3CB/A01 0.355 14x14 9.9 1.91 1.91 BDN19-5CB/A01 0.555 9x9 7.8 BDN20-3CB/A01 0.355 15x15 9.1 2.01 2.01 BDN20-5CB/A01 0.555 9x9 7.2 BDN21-3CB/A01 0.355 16x16 8.5 2.11 2.11 BDN21-6CB/A01 0.605 9x9 6.5 * Thermal resistance of adhesive tape is included. ** Thermal resistance values based on power density of 3 watts/in.2 *** Part numbers listed for standard black anodized heat sinks with IERC adhesive tapes. 5.7 6.8 5.2 6.0 4.7 5.6 4.2 4.5 3.8 4.5 3.5 3.8 3.2 3.5 2.8 2.9 2.7 2.8 2.5 2.6 2.2 Conclusion Critical components running at maximum speeds will generate heat and create thermal management challenges that must be addressed. One solution may be the easy-to-use CTS/IERC Peel and Stick heat sinks. For more information on CTS/IERC’s full line of heat sink products, including copper and aluminum forgings, visit the following site: http://www.ierc.net IERC Burbank, California June 2006 CTS Electronic Components www.ctscorp.com Page 2 Application Note June 06 AN1010