Patent ID: 6874567

Claim:
A cooling apparatus boiling and condensing refrigerant comprising; a refrigerant container which has a heat-generating member attached to a bottom surface therefore and which reserves therein refrigerant which can be boiled by receiving heat from said heat-generating member, a heat radiating portion having a plurality of tubes, which are connected to the inside of the refrigerant container and are provided substantially upright on an upper surface of said refrigerant container, and a header tank by which the plural tubes are communicated; wherein the refrigerant reserved in said refrigerant container can be boiled and evaporated by receiving heat from said heat-generating member and can be used to cool the heat-generating member by radiating latent heat of the refrigerant vapor from said heat radiating portion; and wherein assuming that a portion of the upper surface of the refrigerant container on which a mounting portion of the heat-generating member is projected is referred to a boiling area, at least a tube of the plurality of tubes located within said boiling area has a passage defined by a lower end opening portion connected to the refrigerant container and has a cross sectional area of the passage larger than that of the tube located outside the boiling area.