Stacking-type header and method of manufacturing stacking-type header

A stacking-type header comprising:

• a first plate having a first through-hole;
• a second plate having a plurality of second through-holes;
• a third plate in which a flow path that communicates between the first through-hole and the second through-holes is formed, the third plate being disposed between the first plate and the second plate;
• a first pipe including a first end portion inserted into the first through-hole;
• a plurality of second pipes each including a second end portion inserted into a corresponding one of the second through-holes;
• and
• brazing portions provided between the first plate and the third plate, between the second plate and the third plate, between the first through-hole and the first pipe, and between the second through-holes and the second pipes,
• wherein the first pipe includes a first expanded portion in the first end portion, the first expanded portion having an outer peripheral surface pressed against an inner peripheral surface of the first through-hole,
• wherein each of the second pipes includes a second expanded portion in the second end portion, the second expanded portion having an outer peripheral surface pressed against an inner peripheral surface of a corresponding one of the second through-holes, and
• wherein the first pipe includes a first large diameter portion in a section thereof that is not inserted into the first through-hole, the first large diameter portion having an outer diameter larger than an inner diameter of the first through-hole.