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High heat flux management schemes in laser diodes require appropriate cooling applications. Micro channel coolers are now widely used in high power laser diode industry with the highest total thermal resistance reported as low as 0.03 cm2-K/W with pressure drops as low as 10∼50 psi. Since, the geometries, flow rates as well as high heat fluxes of current SOA LD micro-coolers differ, it is necessary...
A simple concept of characteristic thermal length is used to develop a physics-based compact thermal circuit model for the multi-gate field effective transistor (MuGFET) structure including the device channel, fins, source/drain/poly pads, metal contacts, poly wire and metal mires. The characteristic thermal lengths are used to represent various heat loss paths of heat conduction along each segment...
Solid state light sources, such as light emitting diodes (LEDs), provide many inherent benefits and will dominate the lighting industry in the coming decades. While much of the industry is currently focused on packaging LED technology in standardized 19th century form factors to address the massive installed base of traditional fixtures, the unique characteristics of solid state devices can and will...
Recent progress using a micro-thermal stage (MTS) allowed the control the temperature of microstructures with sub-μs time scales. This approach was applied to phase-change memory (PCM) cells to measure thermal material and device properties. In this work, we use the change in MTS thermal resistance to predict changes in the thermal conductivity or thickness of the nearby phase-change layer (PCL)....
A stainless steel direct liquid contact microchannel cold plate is investigated for the thermal management of bare die packages. Experiments are conducted for a prototype microchannel cold plate in contact with a 1.18cm2 uniformly heated thermal test vehicle. The junction-to-fluid thermal resistance is measured to be 0.21 °C/W for a water flow rate of 1 L/min thru the cold plate. Dynamic thermal characterization...
Currently, a variety of Thermal Interface Materials (TIMs) are required to meet specific requirements for various products with no single TIM meeting the needs for all CPU market segments. Surface treatments, reflow temperatures, mechanical load, performance targets all play a role in choosing a specific TIM. Based on the above multitude of conditions, it is desirable to find a universal TIM that...
Through-Silicon-Vias (TSVs) enable 3D stack of logic processor and memory dies with significant improvement in latency and energy efficiency of large memory-bound computations. However, additional layers of memory die increase IC package thermal resistance. Thermal management has been identified as a key challenge to achieve high computation power and memory density in the same package. In this paper...
Improved-efficiency heat spreaders must address ergonomic- and performance-driven thermal management demands of electronic devices of increasingly thin form factor. Heat pipes offer a potential high-conductance solution, but performance limitations unique to sub-millimeter thickness devices must be characterized. Using a reduced-order, one-dimensional resistance network and a two-dimensional numerical...
An ultra-thin polymer pulsating heat pipe (PPHP) was developed by forming with UV curable polymer resin on polyethylene terephthalate films and hydrofluoroether was used as a working fluid. The casing materials were selected in consideration of compatibility between case materials and the working fluid and also the heat and pressure durability. A new apparatus was constructed to evaluate the thermal...
In this paper, a phase change material (PCM) based heat sink was proposed and its geometry was optimized for heat transfer enhancement. The thermal resistance network between the heat source and the control volume was applied to analyze the influence on heat storage performance of the phase change material based heat sink (PCMBHS) and the optimization suggestions were proposed. Besides, the heat storage...
This paper deals with the system design, technology and test of a novel concept of integrating Silicon power dies along with thermo-electric coolers and a phase change heat buffer in order to thermally manage transients occurring during operation. The concept features double-sided cooling as well as new materials and joining technologies to integrate the dies such as transient liquid phase bonding/soldering...
Physically larger more complex server processors are creating or exacerbating thermal and mechanical challenges in platform design. The larger processors are due, in large part, to the ever increasing core count, increasing integration, and growing I/O performance requirements which pushes pin count demand upwards on the socket thus driving higher processor loading requirements. As a direct result...
A thermal model has been developed to simulate the performance of thermoelectric cooling for two avionics scenarios, where utilizing commercial off the shelf (COTS) components is highly desirable. Modeling predictions were validated through a series of experiments which studied the two scenarios at varying heat loads and heat sink thermal resistances. In these experiments, component temperatures were...
Nowadays, thermal designers have to deal with sophisticated 3D component packaging, enclosing several chips or conventional individually-packaged Integrated circuits with various power densities, embedded in small volumes that will drive up the complexity of their thermal management.
Packaging of optoelectronic devices becomes more and more challenging due to higher heat generation per unit volume. We experimentally investigated the packaging thermal resistance for a semiconductor laser device and compared results for two material alternatives for the electrical passivation layer. We used the time-resolved thermoreflectance technique to obtain the time response for the thermal...
The steady state method is a commonly used and in principle simple way to measure thermal resistance and conductivity of thermal interface materials (TIMs). The sample must be positioned between a hot and a cold plate with constant temperatures, whereby a heat flow through the sample and temperature gradient across the sample are generated. To determine the thermal resistance of the sample the heat...
With increasing power density in electronics packages/modules, thermal resistances at multiple interfaces are a bottleneck to efficient heat removal from the package. In this work, the performance of thermal interface materials such as grease, thermoplastic adhesives and diffusion-bonded interfaces are characterized using the phase-sensitive transient thermoreflectance technique. A multi-layer heat...
In this study, as a passive energy conversion/transport device, the performance of a pulsating heat pipe (PHP) using nanofluid is experimentally investigated. It has been suggested that nanofluids could improve the performance of wickless self-sustaining heat pipes. The transparent fused quartz tubing with 3 mm diameter is used to visualize the oscillations within the adiabatic section of the pipe...
Microfluidic cooling shows promise in cooling next generation 3D microsystems when integrated with through-silicon-vias. In this work, electrical and thermal effects of staggered micropin-fin heat sink dimensions are analyzed using deionized water. An experimental study of five different silicon micropin-fin arrays with a nominal height of 200 µm and diameters down to 30 µm was conducted at flow rates...
The ever-increasing demand for more functionality of electronic and optoelectronic components led to increased packaging and thermal power densities. Higher processing density can be reached by developing thermal management solutions. The current technology in electronic packaging is to attach the die to heat spreader, using materials known as Thermal Interface Materials (TIM), such as solder or silver...
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