Patent ID: 6424529
Filing Date: 2002-07-23
Classification: F28F,H01L

Abstract:
A heat sink for electrical or electronic components comprising:a heat spreader plate to which the components to be cooled are connected; at least three heat conducting fins positioned adjacent to one another in a substantially radial configuration and which are connected substantially perpendicular to said heat spreader plate; highly porous heat conducting reticulated foam block that fills the space between adjacent fins; and wherein: the fin height, b, is determined by the relationship, b=0.6498&it;kf&it;Î´fhwhere,lcf is the thermal conductivity of the selected fin material, Btu/ft s Â° F. &dgr;f is the fin thickness, ft h is the convective heat transfer coefficient for the foam-filled space bounded by the fins and the spreader plate, Btu/ft2 s Â° F., and where h is given by the formula, h=1.2704&it;â€ƒ[n0.50(1-Ï†)0.25]&it;â€ƒ&it;(Ï 0.50&it;k0&it;â€ƒ&it;.63&it;cp0&it;â€ƒ&it;.37Î¼0.13)&it;um0.50&it;Î¨where,n is the linear density of the foam material, pores per ft Ã¸ is the foam porosity expressed as a fraction &rgr; is the density of the flowing fluid, lbm/ft3 k is the thermal conductivity of the flowing fluid, Btu/ft s Â° F. cp is the isobaric specific heat of the flowing fluid, Btu/lbm Â° F. &mgr; is the dynamic viscosity of the flowing fluid, lbm/ft s um is the mean velocity of the flowing fluid, ft/s &PSgr; is <1.