High performance heat exchange assembly

A method of making a heat sink comprising a heat spreader plate, at least two fins and reticulated foam block that fills the space in-between the fins comprising,

• selecting said heat spreader plate, said fins and said foam block;
• assembling said fins and said foam block onto said spreader plate so that said fins are substantially parallel to one another and substantially perpendicular to said spreader plate and said foam block fill the space in between said fins;
• and
• bonding the assembly of said fins and said foam block to said spreader plate.

A method of cooling electronic components by attaching the electronic components to one surface of a heat sink and passing a cooling fluid over the opposing surface of the heat sink, wherein said heat sink comprises,

• a heat spreader plate,
• at least two heat conducting fins that are positioned substantially parallel to one another and which are connected substantially perpendicular to said heat spreader plate, and
• highly porous heat conducting reticulated foam block that fills the space between parallel fins,
• wherein the height of said fins, b, and is determined by the relationship,
• 10 b = 0.6498 ⁢ k f ⁢ δ f h
• where,
• kf is the thermal conductivity of the selected fin material, Btu/ft s ° F.
• δf 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 ° F., and where h is given by the formula,
• 11 h = 1.2704 ⁢ [ n 0.50 ( 1 - φ ) 0.25 ] ⁢ ⁢ ( ρ 0.50 ⁢ k 0.63 ⁢ c p 0.37 μ 0.13 ) ⁢ u m 0.50
• where,
• n is the linear density of the foam material, pores per ft
• Φ is the foam porosity expressed as a fraction
• ρ is the density of the flowing fluid, lbmft3
• k is the thermal conductivity of the flowing fluid, Btu/ft s ° F.
• cp is the isobaric specific heat of the flowing fluid, Btu/lbm ° F.
• μ is the dynamic viscosity of the flowing fluid, lbm/ft s
• um is the mean velocity of the flowing fluid, ft/s
• and wherein the fin spacing, a, is determined by the relationship,
• a=Φδ
• where,
• Φ is between 1 to 6 6, ft, is determined by the relation,
• 12 δ = 7.32 ⁢ ⁢ kc ρ ⁢ ⁢ c p ⁢ u m
• where,
• c is the selected fin length in the flow direction, ft
• k is the thermal conductivity of the flowing fluid, Btu/ft s ° F.
• ρ is the density of the flowing fluid lbmft3
• cp is the isobaric specific heat of the flowing fluid, Btu/lbm° F.
• um is the mean velocity of the flowing fluid, ft/s.