Method for fabricating a heat sink having nested extended surfaces

Abstract

A plurality of substantially similar fins is produced from the thermally conductive and formable sheet stock, for example aluminum or copper, preferably using a set of matched forming dies. Each die in the set produces a fin that is cupped in side elevation. Each fin has two flanges (in the preferred embodiment) extending from the base portion of the cup, and the fin is preferably rectangular in plan. The die cavities are substantially identical in geometry, but differ slightly in dimension so that the base portion of the cup-shaped fin-pair produced by each die in a set varies in width. Each die in the set includes a feature for producing a locating lug or dimple, or alternatively a hole, in each fin produced. The plurality of substantially geometrically identical, but dimensionally differing fin-pairs are then assembled in a nested stack in accordance with the invention. Each fin-pair in the stack is substantially identical in geometry but the base portion of each fin is successively smaller in dimension, moving axially from top to bottom of the fin stack, to allow for the nesting and so that edges of successive fins define gaps of predetermined dimension. The dimple allows for registration and fine alignment and as the nested dimple substantially align themselves as each fin is assembled in the stack. An interference fit between the dimples may be used to secure the assembled stack. Conventional fabrication techniques are optionally used, including bonding, welding, and brazing, to secure the nested fins to each other. Alternatively, a through hole may be used to effectuate both location of the nested fins and provide for mechanical fastening.

Dependencies are inferred from the claim text.