Patent ID: 8251131

Claim:
A cooling device comprising a heat absorbing unit, provided with an inflow port of a coolant medium and a discharge port for discharging said coolant medium, sealing said coolant medium in parts other than said inflow port and said discharge port, wherein said heat absorbing unit includes: an upper member having an installation surface where an object to be cooled is installed, and a cooling surface serving as a back surface of said installation surface; and a lower member forming a chamber having said cooling surface as a part of an inner wall surface together with said upper member, an injection port communicating with said inflow port for injecting said coolant medium toward said cooling surface is provided and said discharge port is provided at a position lower than an opening position of said injection port in said lower member, a plurality of said injection ports are provided in said lower member respectively corresponding to parts where said plurality of semiconductor elements are installed, said lower member is provided with a groove running from the circumference of said injection port to said discharge port in the interior of said chamber for guiding said coolant medium to said discharge port, and cross-sectional area of said groove is increased from the inflow port of flow of said medium to the discharge port.