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Showing 1 to 16 of 16 for “"Thermal Impedance"”.
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Measurement of Thermal Impedance of Deep Ultraviolet Light Emitting Diodes
… and shorten their life span. Consequently, thermal management of high power LEDs is a crucial area of research and development. Thermal impedance is one of the primary parameters characterizing the thermal properties of an LED. Thermal impedance quantifies the rise in the junction …
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Two-dimensional Mapping of Interface Thermal Resistance by Transient Thermal Impedance Measurement
Interconnects in power module result in thermal interfaces. The thermal interfaces degrade under thermal cycling, or chemical loading. Moreover, the reliability of thermal interfaces can be especially problematic when the interconnecting area is large, which increases its predisposition to generate …
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Optimization of Bonding Geometry for a Planar Power Module to Minimize Thermal Impedance and Thermo-Mechanical Stress
… on development a planar power module with low thermal impedance and thermo-mechanical stress for high density integration of power electronics systems. With the development semiconductor technology, the heat flux generated in power device keeps increasing. As a result, more and more stringent …
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Thermal Characterization of Die-Attach Degradation in the Power MOSFET
The thermal performance of the power MOSFET module is subject to change over its lifetime. This is caused by the growth of voids and other defects in the die-attach layer. The goal of this dissertation is to develop measurement techniques and finite element simulations that can measure the changes …
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Analysis of Direct-Soldered Power Module / Heat Sink Thermal Interface for Electric Vehicle Applications
Reducing the thermal impedance between power module and heat sink is important for high-power density, low-cost inverter applications. Mounting a power module by directly soldering it onto a heat sink can significantly reduce the thermal impedance at the module / heat sink interface, as compared to …
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Heat Transfer Issues in Thin-Film Thermal Radiation Detectors
The Thermal Radiation Group at Virginia Polytechnic Institute and State University has been working closely with scientists and engineers at NASA's Langley Research Center to develop accurate analytical and numerical models suitable for designing next-generation thin-film thermal radiation …
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Applications of thermophysical characterization using the 3-omega technique
The 3-omega technique is a commonly used electrothermal technique to characterize thermal conductivity. While most commonly used to characterize isotropic thin films on substrates, the high accuracy and versatility of the technique can be extended to a broader application space, which are explored …
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Metal-cavity surface-emitting nanolasers
… observed such as ultra-narrow linewidth, low thermal impedance, and circular beam shapes. The devices proposed and realized are substrate-free with transferability to other platforms. The size of the proposed structure can be further reduced without severe degradation in the performance. This …
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Low threshold vertical cavity surface emitting lasers integrated onto Si-CMOS ICs using novel hybrid assembly techniques
… show threshold currents of 1 to 2.5 mA and thermal impedances as low as 1.6 OC/mW, similar to native substrate device impedances. This technique intimately connects devices within the dielectric stack, allowing for size independent, wafer scale monolithic processing of heterogeneous …
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Electrical and Thermal Characterizations of IGBT Module with Pressure-Free Large-Area Sintered Joints
… as high melting temperature, high electrical/thermal conductivity, and excellent mechanical reliability. It should be noted, however, that pressure (usually between three to five MPa) was added during the sintering stage for attaching power chips with area larger than 100 mm2. This extra …
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An analytical study of dynamic response and nonequivalence of an absolute active cavity radiometer operating at cryogenic temperatures
A finite-element model describing the dynamic thermal response of an absolute active cavity radiometer is developed. The model considers thermal conduction, diffuse-specular thermal radiation and electrical heat generation. The analysis of diffuse-specular radiation is made possible by the use of …
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Surface Resistance Measurements of Superconducting Niobium Samples with a Triaxial Cavity
… sample and to assess losses in the screw. The thermal impedance between the sample and endplate was also investigated. These possibilities did not explain the observed losses.</p> <p>To eliminate extraneous losses from the installation method, bulk niobium samples were bonded to the endplate …
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Design, Analysis and Experimental Verification of a Mechanically Compliant Interface for Fabricating Reliable, Double-Side Cooled, High Temperature, Sintered Silver Interconnected Power Modules
… for a module design which improves upon module thermal management while also addressing electrical and reliability requirements. The optimum package design enhances heat dissipation with the addition of a substrate bonded to the top electrical pads of the semiconductor devices. The use of …
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Die-Attachment on Copper by Nanosilver Sintering: Processing, Characterization and Reliability
… high die-shear strength of the die-attachment. Thermal performance of nanosilver sintered die-attachment on Cu was evaluated. A system was designed and constructed for measuring both transient thermal impedance (Zth) and steady-state thermal resistance (Rth) of insulated gate bipolar transistor …
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Nanowires for 3d silicon interconnection – low temperature compliant nanowire-polymer film for z-axis interconnect
Semiconductor chip packaging has evolved from single chip packaging to 3D heterogeneous system integration using multichip stacking in a single module. One of the key challenges in 3D integration is the high density interconnects that need to be formed between the chips with through-silicon-vias …