Heat exchanger tube and method of making the same

A method of forming a tube for a heat exchanger, comprising the steps of:

• providing a sheet of elongate, deformable material having a longitudinal axis and a transverse axis, the sheet defining a generally planar base and a pair of terminal edges along the longitudinal length thereof, and one side of the sheet being coated with a braze material;
• folding each of the terminal edges toward one another until they meet so as to form a pair of generally arcuate side portions and a top portion, the braze material being on an outer surface of the side and top portions;
• forming a pair of fluid passageways by bending the terminal edges inwardly toward the base so as to form an acute angle of between 10 to 20 degrees relative to a vertical plane perpendicular to the base of the sheet of material until each edge contacts the base, the step also including forming a braze material receiving area between the terminal edges;
• coating an outside surface of the fluid passageways with a brazing flux;
• heating the fluid passageways at a predetermined temperature to melt the braze material, the flux causing the braze material to flow by capillary flow into the braze material receiving area and substantially filling the area;
• cooling the fluid passageways to solidify the molten braze material to secure the fluid passageways to one another and to secure the terminal edges to the base at a predetermined angle to form the heat exchanger tube.