Abstract: The present invention relates to a heat exchanger (1) comprising: a tube bundle (2) comprising a plurality of tubes (2) placed parallel to one another, said tube bundle (2) comprising fins (6) placed between the tubes (2); two collectors (3), one collector (3) being placed on both sides of the tube bundle (2), each collector (3) comprising a collector plate (4), said collector plate (4) comprising orifices inside which the ends of the tubes (2) are introduced, and a rim (41) forming a groove (42) which is designed to receive a cover (8); and at least one reinforcement plate (10) placed between a collector plate (4) and the fins (6), parallel to the collector plate (4) and brazed against at least part of the tubes (2) of the tube bundle (2) and said collector plate (4), the at least one reinforcement plate (10) comprising a lateral wall (101) which projects in the direction of the collector plate (4), and covers the rim (41) of the collector plate (4) at least partially, said lateral wall (101) being braze

Abstract: The invention concerns a header (3) for a heat exchanger (1) comprising: a header plate (4) comprising orifices intended to receive tubes (2), said header plate (4) comprising a peripheral groove (42), a compressible gasket (44) arranged within the peripheral groove (42), a cover (8) covering the header plate (4) and comprising lateral walls (81) that are inserted into the peripheral groove (42) and compress the gasket (44), the lateral walls (81) of the cover (8) comprising projecting retaining elements (82) that come to bear on the header plate (4).