Microscale Thermoelectric Cooler Assembled From Bulk Materials for Thermal Management of Electronics

Author(s):  
Pradeep Mishra ◽  
Nathan Crane

Electronic device thermal management improvements are critical to continued increases in computing performance. Thermoelectric coolers (TECs) show promise in meeting this need. This paper compares the performance of Bismuth Telluride (BiTe) in three different forms: thin film, bulk, and a hypothetical nanostructured bulk material. This hypothetical materials is based on recent experimental demonstrations in Lead Telluride. Performances of the TEC based on the three different BiTe forms are compared with respect to heat pumping capacity and optimum thickness. The simulations are based on 1-D models that include the effects of thermal and electrical contact resistance. Simulated results show a significant enhancement in maximum heat pumping capacity of ‘Nanostrutured-Bulk TEC’. Modified definitions of heat pumping capacity and coefficient of performance (COP) are proposed for evaluating TECs used to cool objects with temperatures above ambient temperature. It is observed that the appropriate heat sink selection is key factor for achieving the improved TEC performance while maintaining minimum thickness.

Author(s):  
Brian Jensen ◽  
Zhongde Wang ◽  
Kazuhiro Saitou ◽  
John L. Volakis ◽  
Katsuo Kurabayashi

Improving the power handling capability of direct contact RF MEMS switches requires a knowledge of conditions at the contact. This paper models the temperature rise in a direct contact RF MEMS switch, including the effects of electrical and thermal contact resistance. The maximum temperature in the beam is found to depend strongly on the power dissipation at the contact, with almost no contribution from dissipation due to currents in the rest of the switch. Moreover, the maximum temperature is found to exceed the limit for metal softening for a significant range of values of thermal and electrical contact resistance. Since local contact asperity temperature can be hundreds of degrees higher than the bulk material temperature modeled here, these results underscore the importance of understanding and controlling thermal and electrical contact resistance in the switch.


Author(s):  
Anthony M. Pettes ◽  
Marc S. Hodes ◽  
Kenneth E. Goodson

Thermoelectric refrigerators (TEMs) offer several advantages over vapor-compression refrigerators. They are free of moving parts, acoustically silent, reliable and light-weight. Their low efficiency and peak heat flux capabilities have precluded their use in more widespread applications. Optimization of thermoelectric pellet geometry can help, but past work in this area has neglected the impact of thermal and electrical contact resistances. The present work extends a previous one-dimensional TEM model to account for a thermal boundary resistance and is appropriate for the common situation where an air-cooled heat sink is attached to a TEM. The model also accounts for the impact of electrical contact resistance at the TEM interconnects. The pellet geometry is optimized with the target of either maximum performance or efficiency for an arbitrary value of thermal boundary resistance for varying values of the temperature difference across the unit, the pellet Seebeck coefficient, and the contact resistances. The model predicts that when the thermal contact conductance is decreased by a factor of ten, the peak heat removal capability is reduced by at least 10 percent. Furthermore, when the interconnect electrical resistance rises above a factor of ten larger than the pellet electrical resistance, the maximum heat removal capability for a given pellet height is reduced by at least 20 percent and the maximum coefficient of performance at low Ku–∞u/(NK), values is reduced by at least 50 percent.


Author(s):  
Marc Hodes

Sizing the height and cross sectional area of the pellets within thermoelectric modules (TEMs) used to cool, heat and generate power is necessary to optimize their efficiency and/or performance. Here the heat flux that a TEM can accommodate, its coefficient of performance, and its operating current and voltage in refrigeration mode are provided as a function of pellet geometry. This enables designers to, for example, size pellets to refrigerate a load such that the total power consumption of a TEM and a power supply (that converts available voltage to that required by the TEM) is minimized. In generation mode, power output, conversion efficiency and operating voltage and current are provided as a function of pellet geometry and the electrical resistance of a load connected to a TEM. Finally, the effects of electrical contact resistance at the pellet interconnects on the aforementioned parameters are addressed.


NANO ◽  
2015 ◽  
Vol 10 (08) ◽  
pp. 1550118 ◽  
Author(s):  
Lei Wang ◽  
Jing Wen ◽  
CiHui Yang ◽  
Shan Gai ◽  
YuanXiu Peng

Phase-change probe memory using Ge2Sb2Te5 has been considered as one of the promising candidates as next-generation data storage device due to its ultra-high density, low energy consumption, short access time and long retention time. In order to utmostly mimic the practical setup, and thus fully explore the potential of phase-change probe memory for 10 Tbit/in2 target, some advanced modeling techniques that include threshold-switching, electrical contact resistance, thermal boundary resistance and crystal nucleation-growth, are introduced into the already-established electrothermal model to simulate the write and read performance of phase-change probe memory using an optimal media stack design. The resulting predictions clearly demonstrate the capability of phase-change probe memory to record 10 Tbit/in2 density under pico Joule energy within micro second period.


2016 ◽  
Vol 108 (18) ◽  
pp. 181903 ◽  
Author(s):  
Gaurav Singh ◽  
R. L. Narayan ◽  
A. M. Asiri ◽  
U. Ramamurty

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