A method to reduce temperature overshoots in immersion cooling of microelectronic devices

It is demonstrated that the generation of vapor below a heated surface is an effective means of reducing the large superheat required for inception of boiling with liquids suitable for direct-immersion cooling of microelectronic devices. In experiments with R-113 and a plain copper heat sink surface, the incipient boiling superheat was reduced from 33 K to as low as 8 K. With sintered boiling surfaces, the incipient boiling superheat was reduced from 22 K to as low as 7 K. A reasonable explanation for the effectiveness of this sparging technique is that the impacting bubbles activate temporarily dormant cavities that, in turn, activate large neighboring cavities. The technique appears to be easily adaptable to liquid incapsulated modules containing arrays of microelectronic devices such as chips.<>