Heat transport device and method for manufacturing same

A heat transport device comprising:

• a first set of flow passages for flowing a first fluid;
• a second set of flow passages for flowing a second fluid;
• and
• a cross-section A satisfying Requirement 1, Requirement 2, and Requirement 3,
• wherein Requirement 1 is that the cross-section A is a cross-section perpendicular to the second set of flow passages and an interior of the cross-section A is a unified structure and has only a metal surface,
• Requirement 2 is that at the cross-section A, holes of the second set of flow passages are separated by a plurality of partition plates stacking along a first direction, each of the plurality of partition plates having alternating recesses and protrusions along a second direction perpendicular to the first direction, the plurality of partition plates are positioned parallel in a layered form along the first direction, and when at least a pair of partition plates which are adjacent two partition plates are named as a partition plate B and a partition plate C, respectively, and a point α which is a peak apex of the partition plate B facing, along the first direction, the partition plate C on a surface of the partition plate B, which faces a first passage of the second set of flow passages, is compared with a point β which is a valley apex of the partition plate C facing, along the first direction, the partition plate B on a surface of the partition plate C, which faces the first passage of the second set of flow passages, the point α is present on a first line extending along the second direction, the point β is present on a second line extending along the second direction, and the first line is located closer toward a side of a peak apex of the partition plate C than the second line, and a space between the pair of partition plates corresponds to the first passage of the second set of flow passages as one of the holes in which the second fluid flows, and
• Requirement 3 is that the first set of flow passages are formed in an inside of one partition plate of the plurality of partition plates, and the first set of flow passages are not parallel to the second set of flow passages.