Heat exchanger and method of manufacturing the same

A method of manufacturing a heat exchanger, the method comprising:

• a tube manufacturing step of producing a plurality of three-step tubes, each having a three-layered section and each having a liquid passage at a middle portion and module insertion spaces at opposite sides of the liquid passage for receiving one or more thermoelectric modules;
• a coupling step including:
• coupling cooling fins to an outer surface of the three-step tubes such that the three-step tubes and the cooling fins are stacked laterally with respect to each other;
• disposing an upper tank and a lower tank at an upper side and a lower side of the three-step tubes, respectively;
• and
• brazing the three-step tubes, the cooling fins, the upper tank, and the lower tank using a same filler material comprising a metal;
• an opening forming step of cutting a front side and a rear side of one or each of the three-step tubes after the coupling step to form a front opening and a rear opening;
• a module inserting step of inserting a thermoelectric module into a module insertion space of the one or each of the three-step tubes through the front opening or the rear opening;
• and
• a front side sealing step of blocking the front opening.