Heat exchanger

A heat exchanger, comprising;

• a pair of headers constituted by a longitudinal tank member which has a transverse cross-section having a predetermined curvature and a tube attachment member which is joined in the longitudinal direction opposing to the tank member;
• and
• a tube communicating between the headers to allow a refrigerant flowing therethough,
• the tank member being provided with
• (a) a brazing material layer provided at least at a joining face with respect to the tube attachment member, and
• (b) a plane portion formed at an inner peripheral face adjacent to the joining face with respect to the tube attachment member,
• the tube attachment member being provided with
• (a) a brazing material layer provided at least at a joining face with respect to the tank member,
• (b) a plane portion formed at an inner peripheral face adjacent to the joining face with respect to the tank member,
• (c) a first curvature portion which is formed in the vicinity of the joining face with respect to the tank member and has a predetermined curvature, and
• (d) a second curvature portion which is formed at a central portion interposed between both sides by the first curvature portion and has a curvature larger than that of the curvature portion of the tank member, and
• a connecting position between the first curvature portion and the second curvature portion of the tube attachment member being positioned inside of an attachment region of the tube to be attached to the tube attachment member.