Recent advances in low cost cryogenic coolers for electronics

The benefits of cryogenic cooling of electronics have been known for many years. The most obvious advantage of such cooling is the reduction of Johnson noise but, in general, cooling has other advantages, some of which are: lower lead resistance and higher mobility in metals and semiconductors that allow higher operating speed for semiconductor chips; and at sufficiently low temperatures access to the unique capabilities of superconducting electronics. The problem with this is that the refrigerators needed to produce the cryogenic environment have been too expensive to be incorporated in any but the most exotic systems, and, because of this the market for these coolers has never grown to enable a reduction of costs that would then have allowed the market to expand. Things are now changing. During the past decade low cost cryocoolers have been developed based on the use of compressors that were designed and built for the huge home refrigerator market. These compressors cost less than $100 in single units, and can run for twenty to thirty years without a problem. Very low cost coolers are now available that use a cooling cycle related to the vapor-compression cycle of home refrigerators. These coolers are suitable for cooling electronics in the range of -40°C to -200°C. We describe some of this development and its applications to several areas of electronics