The (each) linking part is preferably attached such that its base is flush with the end surfaces of the fin plates in the plate-width direction or is sunken lower than the end surfaces of the fin plates. In such embodiments, the end surface of the fin plates can be brought into contact with an inner-wall surface of the jacket, and consequently heat from the heat generating element mounted on the heat-generating-element mounting surface can be transmitted to every fin plate with good efficiency. As a result, the cooling performance of the heat exchanger can be further improved.

In some embodiments of the present teachings, the (each) linking part may be attached such that the base becomes flush with the end surfaces of the fin plates in the plate-width direction. In such embodiment, the base of the linking part, together with the end surfaces of the fin plates, can be easily brazed to an inner-wall surface of the jacket, and consequently heat from the heat-generating element can be transmitted to every fin plate with even better efficiency. As a result, the cooling performance of the heat exchanger can be further improved.

The positioning protrusions protrude from a side or edge surface of the base part. The height of the positioning protrusions, that is, the distance from a base to a tip of each positioning protrusion in the direction at a right angle to the longitudinal direction of the base, is preferably 1 mm or more. By setting the height of the positioning protrusions to 1 mm or more, the portions of base located between adjacent positioning protrusions can be easily inserted into the respective latching grooves of the fin plates. In addition, the positions of the fin plates can be further stabilized by the one or more linking parts.