Heat sink and laser diode

摘要

The present invention is directed to improve reliability by preventing deterioration in the structure of an inner wall of a water channel (3) caused by galvanic corrosion. A heat sink (1A) in which a water channel (3) of a cooling fluid is formed by stacking and bonding a plurality of thin plates (21-25), in which a surface in the water channel is made of the same metal material except for at least an end of a bonded part of the thin plates.