Experimental investigation of subcooled liquid nitrogen impingement cooling of a silicon chip

A technique was developed to facilitate subcooled pool boiling and jet impingement boiling of liquid nitrogen at the surface of a silicon chip by varying the dewar pressure while maintaining the bath temperature constant at about 78 K. Subcooling levels of up to 10 K could be easily reached by pressurizing the liquid nitrogen bath with helium gas. Convective and boiling impingement cooling of up to 80 W/cm/sup 2/ from a silicon chip has been measured for a submerged subcooled liquid nitrogen jet.