Cam-type retainer clip for heat sinks for electronic integrated circuits

A heat sink assembly including a heat sink and a spring retainer clip providing cooling to an electronic integrated circuit device, the device being mounted in a housing, such as a socket or a module, the housing having engagement means for the spring retainer clip, said heat sink assembly comprising:

• a heat sink including a metallic plate with a plurality of fins projecting upwardly from the
• top surface of the plate defining a series of channels;
• and
• such spring retainer clip comprising two members:
• an elongated, resilient metal strap received in one of said channels and holding means at each end of said strap engaging the engagement means on the housing, said strap having a length such that when it is in engagement with the housing, the center portion of the strap is spaced a pre-determined distance above the upper surface of the heat sink base when the strap is not in tension;
• and
• a cam-type latch pivotally mounted in the center portion of the strap and including a cam with a bearing surface, the distance from the pivot access to the bearing surface being greater than the distance between the pivot access and the upper surface of the base of the heat sink when said strap is not in tension, and an arm fixedly mounted to said cam, said arm when rotated causing said cam to bear against the surface of the base of the heat sink placing the strap in tension so as to force the heat sink into heat conducting engagement with the housing.

A combination heat sink and heat sink retainer clip, for attachment to a rectangular electronic module wherein the rectangular electronic module contains a printed circuit board and at least one semiconductor device, has at least one major wall which is substantially flat and made of a heat conducting material such as metal, and includes at least two spaced apart openings each adjacent one of the longer edges of the wall,

• said heat sink having a rectangular base substantially the same size as the electronic module major wall and a plurality of cooling fins defining at least one channel, said at least one channel aligned transversely between the at least two spaced apart openings in the electronic module wall;
• and
• said retainer clip comprising:
• an elongated, resilient, metal strap received in said at least one channel and holding means at each end engaging one of the openings in the module wall, said strap having a length such that with each end in engagement with one of the module wall openings, the center portion of the strap is spaced a predetermined distance above the upper surface of the heat sink base when the strap is not in tension;
• and
• a cam-type latch is pivotally mounted in the center portion of the strap and including a cam with a bearing surface, the distance from the pivot axis to the cam bearing surface being greater than the distance between the pivot axis and the upper surface of the base of the heat sink when said strap is not in tension, and an arm fixedly mounted to said cam, said arm when rotated causing said cam to bear against the surface of the base of the heat sink and placing the strap in tension so as to force the heat sink into heat conducting engagement with the module wall.