Patent ID: 7032313

Claim:
A method of fabricating a heat exchanger comprising: a) providing a plurality of generally parallel tube runs of a flattened heat exchange tube having a major dimension and a minor dimension; b) providing a plurality of plate fins, each having a plurality of tube slots approximately equal to the number of tube runs, each slot opening to an edge of the associated fin and having I) a shape corresponding to the cross-sectioned shape a tube run to be received in the slot, ii) a depth less than the major dimension of the tube run to be received in the slot, and iii) a width approximately equal to or slightly less than the minor dimension of the tube run to be received in the slot; c) fitting the tube runs snugly into corresponding slots in each of the fins such that an edge of each tube run extends a distance out of the slots in which it is received; d) locating the assembly resulting from step c) on a supporting surface with said tube run edges in contact with said supporting surface and with said plate fins extending above said tube runs; and e) subjecting said assembly to an elevated temperature sufficient to braze said fin to said tube runs while said assembly is on said supporting surface and in the absence of brazing fixtures holding said fins and said tube runs in assembled relation.