Electrodeposited Copper-Graphite Composites for Low-CTE-Integrated Thermal Structures

2017 ◽  
Vol 14 (2) ◽  
pp. 56-62
Author(s):  
Shreya Dwarakanath ◽  
P. Markondeya Raj ◽  
Kaya Demir ◽  
Vanessa Smet ◽  
Venky Sundaram ◽  
...  
Keyword(s):  
High Temperature ◽  
High Power ◽  
Process Development ◽  
Coefficient Of Thermal Expansion ◽  
Composite Films ◽  
Graphite Composite ◽  
Heat Spreaders ◽  
Cte Mismatch ◽  
Graphite Composites ◽  
Modeling Of Properties

Abstract Emerging high-power and high-temperature electronic modules require thick copper structures for power supply, thermal vias, heat spreaders, and also as carriers or lead frames for high-power packages. Such structures should coexist with glass and other substrates with low coefficient of thermal expansion (CTE) to meet high-temperature performance, dimensional stability, and superior device interconnection reliability with low stresses and warpage. The primary challenge with these packages arises from the CTE mismatch between the conductors and the substrates. Cu-graphite composites with glass-matched CTE are explored to address this challenge through analytical modeling of properties such as CTE, Young's modulus and thermal conductivity, finite-element-modeling predictions of glass warpage and stresses, process development to deposit copper-graphite composite films with high graphite loading of 64 vol. %, and warpage measurements using shadow moiré. Results indicate that Cu-graphite composites can mitigate the warpage and stress issues in high-temperature and high-power packages.

Electrodeposited copper-graphite composites for low-CTE integrated thermal structures

2016 ◽  
Vol 2016 (1) ◽  
pp. 000088-000093
Author(s):  
Shreya Dwarakanath ◽  
P. Markondeya Raj ◽  
Kaya Demir ◽  
Vanessa Smet ◽  
Venky Sundaram ◽  
...  
Keyword(s):  
High Temperature ◽  
High Power ◽  
Process Development ◽  
Coefficient Of Thermal Expansion ◽  
Composite Films ◽  
Graphite Composite ◽  
Heat Spreaders ◽  
Cte Mismatch ◽  
Graphite Composites ◽  
Modeling Of Properties

Abstract Emerging high-power and high-temperature electronic modules require thick copper structures for power-supply, thermal vias, heat-spreaders, and also as carriers or lead-frames for high-power packages. Such structures should coexist with glass and other low-CTE substrates to meet high-temperature performance, dimensional stability and superior device interconnection reliability with low stresses and warpage. The primary challenge with these packages arises from the coefficient of thermal expansion (CTE) mismatch between the conductors and the substrates. Cu-graphite composites with glass-matched CTE are explored to address this challenge through analytical modeling of properties such as CTE, Young's modulus and thermal conductivity, FEM predictions of glass warpage and stresses, process development to deposit copper-graphite composite films with high graphite loading of 64 vol. %, and warpage measurements using shadow-moiré. Results indicate that Cu-graphite composites can mitigate the warpage and stress issues in high-temperature and high-power packages.

scholarly journals Silicon Oxycarbide-Graphite Electrodes for High-Power Energy Storage Devices

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4302
Author(s):  
Dominik Knozowski ◽  
Magdalena Graczyk-Zajac ◽  
Grzegorz Trykowski ◽  
Monika Wilamowska-Zawłocka
Keyword(s):  
Energy Storage ◽  
High Power ◽  
Sol Gel ◽  
Lithium Ion ◽  
Silicon Oxycarbide ◽  
Energy Storage Devices ◽  
Graphite Composite ◽  
Storage Devices ◽  
Lithium Ion Capacitor ◽  
Graphite Composites

Herein we present a study on polymer-derived silicon oxycarbide (SiOC)/graphite composites for a potential application as an electrode in high power energy storage devices, such as Lithium-Ion Capacitor (LIC). The composites were processed using high power ultrasound-assisted sol-gel synthesis followed by pyrolysis. The intensive sonication enhances gelation and drying process, improving the homogenous distribution of the graphitic flakes in the preceramic blends. The physicochemical investigation of SiOC/graphite composites using X-ray diffraction, 29Si solid state NMR and Raman spectroscopy indicated no reaction occurring between the components. The electrochemical measurements revealed enhanced capacity (by up to 63%) at high current rates (1.86 A g−1) recorded for SiOC/graphite composite compared to the pure components. Moreover, the addition of graphite to the SiOC matrix decreased the value of delithiation potential, which is a desirable feature for anodes in LIC.

Microwave Assisted Self-Propagating High-Temperature Synthesis for Joining SiC Ceramics and SiC/SiC Composites by Ni-Al System

2015 ◽  
Vol 727-728 ◽  
pp. 213-218 ◽  
Author(s):  
Shao Hua Han ◽  
Roberto Rosa ◽  
Valentina Casalegno ◽  
Milena Salvo ◽  
Paolo Veronesi ◽  
...  
Keyword(s):  
High Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Chemical Vapor ◽  
Atomic Ratio ◽  
Temperature Synthesis ◽  
Sic Ceramics ◽  
High Temperature Synthesis ◽  
Interface Bond Strength ◽  
Cte Mismatch ◽  
Sic Composites

Microwave has been applied to ignite the Self-propagating High-temperature Synthesis (SHS) of compacted Ni-Al mixtures, having 1:1 atomic ratio, in order to join Chemical Vapor Deposition (CVD) SiC ceramics and SiC/SiC composites. The average joint thickness of CVD SiC joint is about 200 μm and the Coefficient of Thermal Expansion (CTE) mismatch between CVD SiC and Ni-Al intermetallic compounds results in a interface bond strength inferior to that of the substrate and joining material; on the other hand, for the SiC/SiC composite joints, as a result of the porosity of SiC/SiC composites, the SHS products readily infiltrated into the pore spaces of the composite, leading to an increased porosity of the joint area and a better lower interface than the upper one. The mechanical strength of the joints has been evaluated by Single-Lap (SL) shear test at room temperature; neither of the ceramic joints nor the composites joint gave satisfactory results, but the ceramic joints reaching a maximum shear strength value of 56MPa exhibited a positive aspect for further experiments.

Development of a Silicon Nitride High Temperature Power Module

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000172-000179
Author(s):  
Michael J. Palmer ◽  
R. Wayne Johnson ◽  
Mohammad Motalab ◽  
Jeffrey Suhling ◽  
James D. Scofield
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Metal Matrix ◽  
Coefficient Of Thermal Expansion ◽  
Matrix Composites ◽  
Power Module ◽  
Ceramic Fracture ◽  
Power Modules ◽  
Active Metal ◽  
Cte Mismatch

Silicon nitride (Si3N4) offer potential advantages as a substrate for high temperature power packaging. Si3N4 has higher fracture strength than alumina and aluminum nitride. The coefficient of thermal expansion (CTE) of Si3N4 is ~3 ppm/°C and the thermal conductivity ranges from 30–50W/m-K. Active metal brazed Cu-Si3N4 substrates are commercially available for power modules. However, the large mismatch in CTE between Si3N4 and Cu results in ceramic fracture and delamination with the wide temperature thermal cycling ranges encountered in high temperature applications. In this work Cu-Carbon and Cu-Mo metal matrix composites have been investigated to reduce the CTE mismatch. The process details are presented along with finite element modeling of the proposed structure. Ultimately, the proposed structure was unsuccessful.

scholarly journals High-Temperature Oxidation of NiAlCr–Ca and NiAlCr–Sr Alloys in Air

2020 ◽  
Author(s):  
Yunus Azakli ◽  
Kerem Ozgur Gunduz ◽  
Sezgin Cengiz ◽  
Yucel Gencer ◽  
Mehmet Tarakci
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Coefficient Of Thermal Expansion ◽  
Complex Oxides ◽  
Scale Spallation ◽  
Temperature Oxidation ◽  
Cte Mismatch

AbstractIn this study, interrupted oxidation behavior of synthetic NiAlCr–Ca (Ca = 0.3, 1.4, 2 at.%) and NiAlCr–Sr (Sr = 0.4 at.%) alloys in the air at 1027 °C for 192 h was investigated. Parabolic rate constants (kp) showed that the Sr-containing alloy exhibited the best oxidation resistance among the alloys investigated in this study. The oxide scale formed on the Sr-containing alloy was composed of α-Al2O3 phase with Sr-rich nodules. Increasing the Ca concentration in the alloys was found to reduce the oxidation resistance due to the formation of non-protective Ca-rich complex oxides and consumption of α-Al2O3 scale by the reaction between Al2O3 and CaO. The Ca-rich complex oxides were initially formed on the Ca-rich interdendritic region and grew with time. Very little scale spallation was observed for the Sr-containing alloy, while it was notable for 0.3 at.% Ca-containing alloy. Spallation was attributed to the coefficient of thermal expansion (CTE) mismatch arisen from the formation of CaAl4O7 phase, a compound with a very low CTE.

scholarly journals Aerosol Jet Printed Nanocarbons on Heat Sink Materials

Proceedings ◽  
2020 ◽  
Vol 56 (1) ◽  
pp. 30
Author(s):  
Reinhard Kaindl ◽  
Bernhard C. Bayer ◽  
Tushar Gupta ◽  
Songfeng Pei ◽  
Pengxiang Hou ◽  
...  
Keyword(s):  
High Temperature ◽  
Carbon Nanotube ◽  
High Power ◽  
Heat Sink ◽  
Temperature Sensors ◽  
Solid Content ◽  
Particle Sizes ◽  
High Current ◽  
Heat Spreaders ◽  
Temperature Applications

Graphene- and carbon nanotube (CNT)-based inks have been printed on relevant heat sink materials by Aerosol jet. The thickness of the layers varied between ~100 and ~1.500 nm. The inks’ viscosity ranged from <20 up to 600 cps at a solid content between 0.18 and 3% and wide particle sizes from 5 nm up to 5 µm. The printed layers could be interesting for rather high-power and high-temperature applications including thermal heat spreaders, resistive heaters, high-current carrying interconnectors, temperature sensors and ordnance fuze technology.

Analysis and Characterization of Thermal Expansion-Matched Wick-Based Multi-Chip Passive Heat Spreaders in Static and Dynamic Environments

2013 ◽  
Author(s):  
David H. Altman ◽  
Anurag Gupta ◽  
Thomas E. Dubrowski ◽  
Darin J. Sharar ◽  
Nicholas R. Jankowski ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Thermal Performance ◽  
High Power ◽  
Coefficient Of Thermal Expansion ◽  
Inertial Force ◽  
Dynamic Environments ◽  
High Heat ◽  
Heat Fluxes ◽  
High Heat Flux ◽  
Heat Spreaders

Ensuring adequate spreading of heat dissipated by high power density devices is a critical part of many electronics packaging designs. In many cases, passive wick-based heat spreaders can offer improved heat spreading performance relative to solid conductor alternatives. However, concerns related to performance degradation in high-inertial force environments frequently limit their use to static or near-static applications. In this work we investigate the performance of low coefficient of thermal expansion (CTE) wick-based heat spreaders cooling multiple high heat flux devices in static and high-g environments. Two high-power devices are simulated using custom-manufactured resistor-thermometer chips, enabling dissipation of die average heat fluxes in excess of 150W/cm2. Comparative thermal performance is evaluated for wick-based heat spreaders and solid CuMo heat spreaders of equivalent CTE affixed with interface materials typical of those used when attaching a low CTE package to a high CTE cold plate (e.g., Al or Cu). Thermal performance is characterized as a function of heat input during exposure to increasing g-forces applied using a custom-built centrifuge. Experimental observations are interpreted through detailed modeling of fluid flow patterns within the wick structure of the passive heat spreader. Results from these experiments demonstrate that properly designed wick-based heat spreaders have utility in both static and dynamic environments, exhibiting effective conductivities in excess of that obtainable with competitive low-expansion composites.

NILO ALLOY 36

Alloy Digest ◽  
1987 ◽  
Vol 36 (8) ◽  
Keyword(s):  
Thermal Expansion ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Constant Coefficient ◽  
Coefficient Of Thermal Expansion ◽  
Heat Treating ◽  
Temperature Performance ◽  
Iron Nickel

Abstract NILO alloy 36 is a binary iron-nickel alloy having a very low and essentially constant coefficient of thermal expansion at atmospheric temperatures. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Fe-79. Producer or source: Inco Alloys International Inc..

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