Cryogenics cooling medium
At what temperature does the term “cryogenic” apply?
A large portion of the scientific community consider cryogenic temperature to be -150°C and below. In North America -180°C is also used which is derived from the boiling points of atmospheric gases.
At the opposite end of the cryogenic temperature range is absolute zero (-273°C) which is the temperature at which all molecular motion ceases. Due to quantum mechanics it isn’t possible to fully reach absolute zero, however scientists have been able to get as close as -272.999999999999°C!
These extremely low temperatures can prove very useful as a means of rapidly transferring excess heat from electronic equipment. It is therefore vitally important to ensure maximum heat transfer between the surface of the hot electronics and the surface of the cryogenic cooling medium.
Apiezon N grease has been specifically developed to perform this function and has been used as a thermal transfer medium for superconducting magnets, cryostats, temperature sensors and a wide variety of other systems to help reach cryogenic temperatures as rapidly as possible.
The Apiezon Technical Team were contacted some time ago by a magazine writing an article on the practice of “overclocking” in high specification computers. Overclocking is the process of making a computer operate faster than the specified clock frequency by modifying system parameters. This does offer benefits when looking to generate the maximum possible processing speed, however overclocking also produces temperatures sufficiently high to damage the computer processor.
Most computer processors have rated operating temperatures of 55°C under full load, however once temperatures reach 80°C the chance of failure is high. As space is of a premium inside computers, a small cryogenic cooling medium is a very effective solution.
The article featured a test in which the heat from a graphics card needed to be transferred to a liquid nitrogen-filled copper pot. A range of ten thermal transfer greases were tested to see which was most effective, and we received feedback that Apiezon N grease came out as one of the top two which was great news!
Unfortunately the article never went to print, but it was a very interesting application and hopefully one that Apiezon N grease will be used in again one day.