Patent ID: 7996990

Claim:
A method of manufacturing a heat exchanger comprising: assembling a first header, a flat tube, fins and a second header by inserting a first end part of the flat tube into the first header, said flat tube extending through said fins, and inserting a second end part of the flat tube into the second header; and pressurizing the flat tube by filling the flat tube with a fluid supplied to the flat tube via the first header and the second header so that the flat tube expands against the fins; wherein the flat tube is a multi-channel flat tube including at least one partition for dividing the inside of the flat tube into a plurality of parallel flow channels, and wherein said pressurizing comprises pressurizing the flat tube so that in the end part, the partition is in a contracted state where at least part of the partition is deformed, and in other parts, the at least one partition extends almost straight.