Cooling characteristics of a nitrogen micromachined Joule-Thomson cooler operating from 88.5 K to 295 K

Abstract

Thermal management is critical in keeping electronic devices operating below their reliable temperature limits. One promising approach is to use vibration-free micromachined Joule-Thomson (JT) coolers that reduce temperature fluctuations in electronic devices. In this study, we systematically examine the cooling power provided by a micromachined JT cooler with dimensions of 60.0 × 9.5 × 1.3 mm3 using nitrogen. A heated silicon chip was attached to the JT cooler to simulate a microelectronic device producing heat load. The cooling power depending on cooling temperature with different insulation conditions and high pressures have been measured. Applying a high pressure of 11.1 MPa and a low pressure of 0.24 MPa, the cooler could cool down from a room temperature of 295 K to 88.5 K in 30 min. A general method is introduced to evaluate the cooling performance of a micromachined JT cooler. The relationship between the cooling performance and the allowed heat load is discussed. It is shown that the potential applications of micromachined JT coolers can be greatly expanded by increasing the high pressure of nitrogen and improving insulation conditions.