There is provided a semiconductor laser device capable of reducing stress
occurring to a semiconductor laser element so that a life of the
semiconductor laser device can be prolonged. In this semiconductor laser
device, a solder layer 114 is absent over a first region R1 ranging to a
specified length L1 in a perpendicular direction X from a center line J1
of a light-emitting region 150 toward both sides of the perpendicular
direction X. That is, the first region R1 over which the light-emitting
region 150 is present serves as an incomplete bonding region between the
solder layer 114 of the semiconductor laser element 100 and a heat sink
200. Thus, stress given to the light-emitting region 150 due to
differences in coefficient of thermal expansion among the semiconductor
laser element 100, the solder layer 114 and the heat sink 200 during
operation is reduced.