Patent ID: 8345425

Claim:
A cooling system for cooling a semiconductor device mounted on an electronic printed circuit board, which is stored within a housing of an electronic apparatus, comprising: a heat-receiving jacket, which is attached on said semiconductor device, being thermally connected with a surface thereof, and which vaporizes a liquid refrigerant received within a pressure-reduced inner space thereof, with heat generation from said semiconductor device; a condenser, which stores the refrigerant vapor from said heat-receiving jacket in a pressure-reduced inner space thereof and condenses the refrigerant vapor by transferring heat outside of the apparatus; a first conduit, which guides the refrigerant vapor from said heat-receiving jacket into said condenser; and a second conduit, which guides the liquid refrigerant from said condenser into said heat-receiving jacket, and thereby applying a thermo siphon for circulating said refrigerant due to phase changes thereof, wherein said condenser has a plurality of cooling tubes for cooling down the refrigerant vapor from said heat-receiving jacket on an inner wall surface thereof, and each of said cooling tubes forms fine grooves on the inner wall surface along a direction of flow of the refrigerant, and is formed flat in a cross-section thereof.