US Patent 7195058 Heat sink made from a singly extruded heatpipe

A heatpipe for cooling an integrated circuit. The heatpipe includes a pipe and radial fins that are formed by extruding a single piece of material, such as heat conducting metal. Each of the radial fins extends away from the pipe and runs (preferably) the length of the pipe. Each radial fin has normally oriented subfins that provide additional heat convection surface areas to the radial fins. Within the pipe are interior fins, also formed during the material extrusion process. The interior fins provide additional conduction cooling to a heat transferring fluid circulating within the pipe.