Abstract: A plurality of heat sinks assembled to form a rack in a lightweight box accommodate printed circuit cards between the heat sinks and circulate cooling oil through the heat sinks to drain the test heat from the boards quickly. Each heat sink includes a porous metal foam core configured in zigzag shape to provide a tortuous path for the fluid flow which extends into lateral fins comprising the side plates of the metal foam for receiving the cards or ground plates therefore. These plates are clamped against the fins for close contact to the cooling fluid thereby shortening the heat flow path. Brazed on aluminum top and bottom cover plates make a fluid tight connection with the porous metal. The brazed on top and bottom plates are also configured in the zigzag pattern of the foam.

Abstract: A plurality of heat sinks assembled to form a rack in a lightweight housing accommodate printed circuit cards between the heat sinks and circulate cooling oil through the heat sinks to drain the test heat from the boards quickly. Each heat sink uses a porous metal foamed core, configured in zigzag shape, to provide a tortuous path for the fluid flow which extends into lateral fins comprising the side plates of the porous metal foam for receiving the cards or ground plates therefore. These plates are clamped against the fins for close contact to the cooling fluid thereby shortening the heat flow path. Brazed on aluminum top and bottom cover plates make a fluid tight connection with the porous foamed metal. The brazed on top and bottom plates are also configured in the zigzag pattern of the porous foamed metal.