Patent ID: 8081465

Claim:
A cooling apparatus for semiconductor chips, comprising: a metal base comprising a first major surface and a second major surface; an insulator base board bonded to the first major surface of the metal base, the insulator base board mounting the semiconductor chips thereon; a plurality of radiation fins formed on the second major surface of the metal base, the radiation fins being integrated with the metal base into a unit; and a duct cover disposed on the metal base to define a duct, the duct cover surrounding the radiation fins, the duct cover comprising an inflow port on a first end thereof and an outflow port on a second end thereof for causing a coolant flow between the radiation fins in one flow direction from the inflow port to the outflow port; wherein the radiation fins is configured for increasing a cooling efficiency thereof in the flow direction of the coolant from the inflow port toward the outflow port; the radiation fins comprise sheet-shaped fins or pin-shaped fins extended along the duct in a flow direction of the coolant respectively arranged in a duct, and a surface area density of the radiation fins is higher gradually from the inflow port toward the outflow port, and the surface area density of the radiation fins is a total surface area of the radiation fins on a unit surface area of the metal base.