The above-mentioned latching grooves are more preferably formed at both end parts of the above-mentioned fin plate in the longitudinal direction, that is, on both sides in the plate-width direction, and the above-mentioned linking parts more preferably hold the above-mentioned plurality of fin plates from (on) both sides in the plate-width direction at both end parts of the above-mentioned fin plates in the longitudinal direction. In such embodiments of the present teachings, the positions of the fin plates can be reliably stabilized by four of the linking parts. As a result, the dimensional accuracy of the heat sink, after it has been assembled and attached to the heat exchanger, can be even further increased.

In some embodiments of the present teachings, the fin plates may have notched parts (or simply “notches”), each of which is recessed from a groove side surface, which form (define) a space between an opening end and a bottom surface of the latching groove, more than the surrounding groove side surface. In addition, claw parts (or simply “claws”) of the fin plates may be designed to press against (crimp) the linking part more on the open-end side than on the bottom wall side of the notched part. In such embodiments, the claw parts can better fix the fin plate, and consequently the dimensional accuracy of the heat sink, after the heat sink has been assembled, can be further increased. Furthermore, after the heat sink has been assembled, the one or more linking parts, the fin plates, and the like can be better prevented from separating from the heat sink, which makes it possible to more easily handle the heat sink during subsequent manufacturing processes.