Method of manufacturing a plate fin heat exchanger and the heat exchanger

Plate fin 3 of the heat exchanger 4, the peripheral edge of the notch 2 of the heat transfer tube 1 is inserted in the flat shape, it has a fin collar 5 which is rising formed from circumferential edge, fin collars 5, the heat transfer tube a position facing the side surface of the long shaft 1, Rifurea portion and the side surface has at least one Rifurea portion 6 is bent to the opposite side, defining an adjacent to the plate fin 3 fin pitch distance between at least one of 6, Rifurea tip 6b is formed away from the contact side of the plate fin 3 in contact with the Rifurea portion 6 which is the tip portion.