Patent ID: 7059130

Claim:
A heat exchanger in which heat is transferred from a heat-extracting area where a first fluid is allowed to flow through the heat-extracting area to a heat-emitting area where a second fluid different in temperature from the first fluid is allowed to flow through the heat-emitting area, wherein a wall is provided to separate the areas from one another, and porous metals are provided in the areas, one to each area, the porous metals being each made on a surface thereof with a junction layer of pasty joining material kneaded with powdery metal, the porous metals being each merged together with the wall through fusion of the associated junction layer to make certain of heat transfer between the wall and the porous metals, and wherein the junction layers are buried in the porous metals in a way coming into contact with opposite sides of the wall, one to each side, and any first junction layer has a high heat-resisting property and a second junction layer has a fusing temperature more than 100° C. lower than the first junction layer, the first junction layer being made of joining material higher in fusing temperature than the second junction layer.