PURPOSE: To obtain the uniform thermal conductivity on each integrated circuit chip as well as to reduce the effect affecting to the cooling efficiency of non- condensable gas by a mthod wherein a hole or an annular part enveloping the protrusion, which is attached to the surface of the chip, is provided on a cooling plate, and then the groove on the inner wall of an annular part and a fin 17 are provided.
CONSTITUTION: A cooling plate 12 is provided adjoining to a wiring substrate 2, an integrated circuit chip 1 and the protrusion 11 attached to the chip 1, and the row of fins 17 is provided on the cooling plate 12 in such a manner that it covers the protrusion 11. The heat generated on the chip is transmitted to a protrusion 3, and bubbles 5 are generated from the protrusion 11. The greater part of the generated bubbles is caught between the annular fins, and a vapor reservoir 18 is formed at the upper part of the groove. The greater part of the vapor generated on each chip is condensed on the circumference of the chip. The vapor bubbles which are not caught by the cooling plate which is coupled to the protrusion 11 is brought to a vapor reservoir 6 located at the upper part of the container, the vapor in the vapor reservoir is condensed on the wall face of the cooling plate, formed into a liquid film flow 20, and flowed back to the liquid reservoir located at the lower part.
HIRASAWA SHIGEKI
NAKAJIMA TADAKATSU
