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Our theoretical studies showed that absorption refrigeration (AR) system and organic Rankine cycle (ORC) are the most promising technology candidates in utilizing the waste heat dissipated by data centers. Since both candidates work with heat of temperatures not less than ∼65°C, this study is limited to water-cooled and hybrid two-phase cooled data centers. However, there exist challenges in the integration...
In the present investigation, steady state thermal analysis of IGBT 6-pack power modules is carried out to keep maximum temperature within permissible limit. Quality and reliability of an IGBT module depends on efficient removal of the heat that is generated. A three dimensional finite element model is constructed using base plate having pins, DBC copper with a solder layer having substrate and IGBT...
In order to dissipate heat from future low form factor microelectronic systems the use of piezoelectric blowers has recently attracted a great deal of attention. These zero-mass flow devices comprised of two piezoelectric membranes, whose oscillation frequency and amplitude can be electrically tuned, provide a net positive momentum which can be used to actively cool various device components. In order...
Phase Change Memory (PCM) technology relies on the contrast in electrical resistance between the amorphous and crystalline states of a chalcogenide active material. Electrical PCM devices use Joule heating by short pulses of current to induce phase change, such that the amount of heat injected into the active material and the rate of cooling determine the final state of material formed. In this paper,...
A model for a basic hot aisle/cold aisle data center configuration was built and analyzed using the commercial computational fluid dynamics (CFD) software FloTHERM. The CFD study was motivated by experimental data that sho wed air recirculatio n from the hot aisle to the cold aisle through the gap between the floor and the bottom of the server cabinet. This flow can be attributed to lower values of...
We report the fabrication and fluid flow characterization of a class of open-cell copper foams known as copper inverse opals (CIOs). This material has finely controlled structure at the pore level, which may enable its use in microscale heat exchangers for microelectronics cooling. We fabricated CIOs by electrodepositing copper around a sacrificial template of packed polystyrene microspheres. We then...
Semiconductor industry has recognized the need to replace traditional Al/SiO2 interconnects with Cu/Low-k interconnects in the mainstream electronics devices following the latter's impact on power, RC delay, and cross-talk reduction. However due to lower elastic modulus, strength, and poor adhesion characteristic, reliability of the Cu/Low-k interconnects turns out to be a concern for its integration...
Surveillance systems have presented to be important applications for high performance thermal control devices, especially passive ones using heat pipe technology. This is usually applied when the heat source is located far from the heat sink and the use of liquid cooling or any other active thermal control system is not possible. Design and application of pulsating heat pipes (PHPs) and heat pipes...
An experimental study is performed to characterize the effect of squeezing conditions on the particle distribution and bond line thickness of particle filled polymeric thermal interface materials (TIM). Two different commercial particle-filled polymeric TIMs with different particle volume fractions have been used in this study. Rheological properties such as yield stress and viscosity are measured...
This is an effort to use natural convection inside a room to enhance the heat flow from a ceiling-mounted recessed LED fixture. Thermal performance of recessed fixtures is evaluated experimentally in a wooden box specified by Underwriters Laboratories, called a UL box. The UL box is approximately 0.67 × 0.62 × 0.46 m and is used to emulate an insulated ceiling for testing purposes. The UL box is suspended...
Percolating and neck-based thermal underfills with significant improvements in thermal conductivity compared with capillary underfills are currently under development. They could be applied between dies to improve the heat dissipation through a 3D chip stack. In this parametric study, we provide insights into the thermal, mechanical, thermo-mechanical and electrical properties achievable by this new...
Ensuring adequate thermal performance is essential for the reliable operation of flip-chip electronic packages. Thermal interface materials (TIMs), applied between the die and a heat spreader form a crucial thermal junction between the first level package and external cooling mechanisms such as heat-sinks and cooling fans. Selection of a good TIM is dependent not only on its thermal properties but...
The LED lighting market is growing annually, however high prices remain a barrier, especially in the incandescent replacement market [1]. Many LED bulbs, such as the A19 (the “classic” light bulb shape), MR16 (Multifaceted Reflector, 16 eights of an inch in diameter), and PAR30 (Parabolic Aluminized Reflector lamp, 30 eights of an inch in diameter) could benefit from the use of plastic materials to...
Self-heating effects severely limit the performance of high-power gallium nitride (GaN) high-electron-mobility transistors (HEMTs). High thermal resistances within micrometers of the transistor junction often dominate the junction temperature rise and fundamentally restrict the device power handling capability. The use of high-thermal-conductivity diamond near the junction can address this thermal...
The demand for power electronic systems to operate in harsh environmental conditions has increased over the past 20 years. These environments include those relating to deep oil-well drilling, automotive and aerospace applications. The miniaturization of the power module along with higher power densities have created elevated stress levels on ancillary subsystems, specifically the control circuitry...
Data centers are very costly structures, both in terms of capital and operational expenditures. The high innovation rate in the IT business conflicts with the long-term character of data centers. In order to ensure lifetime usability, flexibility is a major concern for any data center design. Recent developments of data center air-cooling, in particular containment solutions for hot/cold air separation,...
Thermal management has become a critical part of advanced micro and nano electronics systems due to high heat transfer rates. More constraints such as compactness, small footprint area, lightweight, high reliability, easy-access and low cost are exposed to thermal engineers. Advanced electronic systems such as laptops, tablets, smart phones and slim TV systems carry those challenging thermal needs...
Synthetic jets are being investigated over the last four decades. Researchers have been interested in its unique applications for a wide range of flow control to thermal management of electronics applications. Synthetic jets are made up of actuators such as piezoelectric, magnetic, or linear piston technology etc. In this study, we performed an experimental and numerical investigation of a piezoelectric...
This paper presents a dynamic model for simulating the heat dissipation and the impact of Phase Change Materials (PCMs) on the peak temperature in Lithium-ion batteries during discharging operation of a hybrid truck under different ambient temperatures.
Embedded computing systems used in many military and avionics applications are trending toward higher heat fluxes, and as a result performance is being hindered by thermal limitations. This is intensified by the high ambient conditions experience by today's modern warfighter. In many applications liquid cooling is replacing air flow through chassis for both thermal and environmental benefits. Although...
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