Effect of laminar air flow on probe burn for spring probe
This paper investigates transient heat transfer between a heated spring probe and its air environment. A continuum finite volume simulation is used to analyze of heat flow within and from the resistively heated probe to its environment. Experimental results are conducted for spring probe with laminar air flow and without air flow. The numerical results and experimental results are compared and very good agreement is observed.
Wafer test probe burn modeling and characterization
This study investigates the wafer probe temperature distribution along a probe body in order to model probe burn phenomenon by using computational mechanics techniques. The finite volume software is used to study the effects of different materials and different geometrical factors on the temperature along a special design vertical/spring and cantilever probe. The computation shows higher temperatures towards the probe tip region as a result of Joule heating. The probe burn is also observed at the tip region of spring and cantilever probes in wafer testing. This is believed to be due to very low heat dissipation rates resulting from very small sizes compared to the probe body.
Effects of reservoir volume on performance of pulse tube cooler.
A pulse tube cooler has the advantages of long-life and low-vibration over conventional cryocoolers such as G-M and Stirling coolers because of the absence of moving parts at low temperature. On the other hand, the combination of a reservoir and orifice is indispensable to optimize the performance of pulse tube coolers. In order to make the pulse tube cooler compact for practical applications, the volume of reservoir should be minimized. This paper analyzes the effects of the reservoir volume on the thermodynamic performance of various components in a simple orifice and a double-inlet pulse tube cooler by combining a linearized model with a thermodynamic analysis. Expressions of entropy production for those components are presented. The results show that the reservoir volume has a significant influence on the entropy production in the various components when the reservoir to pulse tube volume ratio is smaller than about 5. The ratio is important to determine the minimum reservoir volume for a pulse tube cooler. Optimum settings for a double-inlet pulse tube cooler are also discussed.