Microchannel crossflow fluid heat exchanger and method for its fabrication

Claim 1

A crossflow fluid heat exchanger comprising a stack of thin metal sheets brazed together so as to be bonded by integral metal-to-metal bonds, said stack including alternating slotted and unslotted sheets, each of said slotted sheets having a plurality of parallel slots formed therein which extend over rectangular central regions of said sheets and which form fluid flow channels when sandwiched between said unslotted sheets, successive slotted sheets in the stack being oriented with their slots extending substantially orthogonally so as to form two sets of fluid flow channels arranged in a crossflow configuration, each of said unslotted sheets including a set of four rectangular manifold openings positioned adjacent the peripheral edges of said unslotted sheet, and wherein each of said slotted sheets includes a set of four rectangular manifold openings adjacent the peripheral edges of said slotted sheet, the manifold openings in said unslotted sheets being wider than the manifold openings in said slotted sheets so as to overlap the ends of the slots in said slotted sheets, whereby said manifold openings of said unslotted sheets and said manifold openings of said slotted sheets are aligned to form internal fluid flow manifolds connecting the opposite ends of the two orthogonal sets of fluid flow channels.