Heat pipe with brazed seam

A heat transfer device comprising:

• a hollow metal body, the hollow body defining:
• a wall having a thickness;
• an internal chamber defined at least in part by the wall;
• a vacuum defined in the internal chamber;
• a seam defined between two different portions of the wall and extending from an internal surface to an external surface of the hollow metal body;
• an evaporation region in which heat is received in the hollow metal body;
• a condenser region from which heat is discharged from the hollow metal body;
• a working fluid within the internal chamber drawing heat from the evaporator region and discharging heat from the condenser region in a working cycle of the heat transfer device,
• wherein the wall comprises an internal polished surface within the hollow metal body, worked to remove or reduce in number or size imperfections that would otherwise accumulate the working fluid;
• and
• a brazing material applied to the internal polished surface to hermetically seal the internal chamber and maintain the vacuum in the internal chamber, wherein the brazing material forms a continuous layer that extends across the seam on the internal polished surface.