Two-Phase Helium Convection Loop For Cryogenic Cooling

Described is a probing system and technique for testing superconducting and low temperature circuitry at the wafer level. In embodiments, the system includes a helium convection loop such as a passive helium convection loop. The use of a passive helium convection loop enables the use of welded flexible bellows hoses. Also described is a wafer holding structure having a fixed portion configured to be removably secured to a wafer to be tested and a second portion configured to be removably secured to the fixed portion and configured to remain in a testing chamber portion of a wafer probing system and configured to provide force application and alignment functionality to a wafer to be tested.