High-performance SiC power devices and modules with high temperature operation

2011 ◽  
Author(s):  
T. Nakamura ◽  
Y. Nakano ◽  
M. Sasagawa ◽  
T. Otsuka ◽  
M. Aketa ◽  
...  
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Power Devices ◽  
High Temperature Operation

On the Integration of Hot Foil Bearings Into Gas Turbine Engines: Theoretical Treatment

2019 ◽  
Author(s):  
Hooshang Heshmat ◽  
James F. Walton
Keyword(s):  
High Temperature ◽  
System Dynamics ◽  
High Performance ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Structural Stiffness ◽  
Foil Bearings ◽  
Foil Bearing ◽  
High Temperature Operation ◽  
Bearing System

Abstract To achieve high power density Gas Turbine Engines (GTEs), R&D efforts have strived to develop machines that spin faster and run hotter. One method to achieve that goal is to use high temperature capable foil bearings. In order to successfully integrate these advanced foil bearings into GTE systems, a theoretical understanding of both bearing and rotor system integration is essential. Without a fundamental understanding and sound theoretical modeling of the foil bearing coupled with the rotating system such an approach would prove application efforts fruitless. It is hoped that the information provided in this paper will open up opportunistic doors to designs presently thought to be impossible. In this paper an attempt is made to describe how an advanced foil bearing is modeled for extreme high temperature operation in high performance turbomachinery including GTEs, Supercritical CO2 turbine generators and others. The authors present the advances in foil bearing capabilities that were crucial to achieving high temperature operation. Achieving high performance in a compliant foil bearing under the wide extremes of operating temperatures, pressures and speeds, requires a bearing system design approach that accounts for the highly interrelated compliant surface foil bearing elements such as: the structural stiffness and frictional characteristics of the underlying compliant support structure across the operating temperature and pressure spectrum; and the coupled interaction of the structural elements with the hydrodynamic pressure generation. This coupled elasto-hydrodynamic-Finite Element highly non-linear iterative methodology will be used by the authors to present a series of foil bearing design evaluations analyzing and modeling the foil bearing under extreme conditions. The complexity of the problem of achieving foil bearing system operation beyond 870°C (1600°F) requires as a prerequisite the attention to the tribological details of the foil bearing. For example, it is necessary to establish how both the frictional and viscous damping coefficient elements as well as the structural and hydrodynamic stiffness are to be combined. By combining these characteristics the influence of frictional coefficients of the elastic and an-elastic materials on bearing structural stiffness and hence the bearing effective coupled elasto-hydrodynamic stiffness coefficients will be shown. Given that the bearing dynamic parameters — stiffness and damping coefficients — play a major role in the control of system dynamics, the design approach to successfully integrate compliant foil bearings into complex rotating machinery systems operating in extreme environments is explored by investigating the effects of these types of conditions on rotor-bearing system dynamics. The proposed rotor/bearing model is presented to describe how system dynamics and bearing structural properties and operating characteristics are inextricably linked together in a manner that results in a series separate but intertwined iterative solutions. Finally, the advanced foil bearing modeling and formulation in connection with resulting rotor dynamics of the system will be carried out for an experimental GTE simulator test rig. The analytical results will be compared with the experiments as presented previously to demonstrate the effectiveness of the developed method in a real world application [1].

Elastomeric Seals for the Army's Lance Missile

1966 ◽  
Vol 39 (4) ◽  
pp. 1233-1246
Author(s):  
S. P. McManus ◽  
S. Pikkn
Keyword(s):  
High Temperature ◽  
Exposure Time ◽  
Chemical Industry ◽  
High Performance ◽  
Propulsion System ◽  
Elastomeric Seals ◽  
Chlorobutyl Rubber ◽  
High Temperature Operation

Abstract The LANCE propulsion system requires dynamic and static seals which must operate under extremely severe conditions for short periods. By analysis and tests it has been found that resin-cured chlorobutyl rubber meets the requirements for low and high temperature operation and retains its properties when exposed to the LANCE propellants for short periods. The chlorobutyl rubber, however, is not a panacea. Its properties become increasingly poorer as exposure time increases. Since the need for high performance, versatile systems should continue indefinitely, it is hoped that research can produce elastomers to meet the growing need for unusual environments such as are described here. For successful accomplishment of this task, the rubber and chemical industry will have to meet the challenge to reach this goal.

High-Temperature Operation of SiC Power Devices by Low-Temperature Sintered Silver Die-Attachment

2007 ◽  
Vol 30 (3) ◽  
pp. 506-510 ◽  
Author(s):  
John Guofeng Bai ◽  
Jian Yin ◽  
Zhiye Zhang ◽  
Guo-Quan Lu ◽  
Jacobus Daniel van Wyk
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Power Devices ◽  
Die Attachment ◽  
High Temperature Operation ◽  
Sintered Silver

190 °C High-Temperature Operation of 905-nm VCSELs With High Performance

2021 ◽  
pp. 1-6
Author(s):  
Meng Xun ◽  
Guanzhong Pan ◽  
Zhuang Zhuang Zhao ◽  
Yun Sun ◽  
Jingtao Zhou ◽  
...  
Keyword(s):  
High Temperature ◽  
High Performance ◽  
High Temperature Operation

An Ultra-Low Noise Instrumentation Amplifer Designed for High Temperature Applications

2012 ◽  
Vol 2012 (HITEC) ◽  
pp. 000082-000086
Author(s):  
Jeff Watson ◽  
Gustavo Castro
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Low Noise ◽  
Silicon On Insulator ◽  
Instrumentation Amplifier ◽  
Leakage Currents ◽  
Comprehensive Reliability ◽  
High Temperature Operation ◽  
Temperature Applications

This paper discusses a very low noise instrumentation amplifier designed specifically for high temperature applications. The device uses a proprietary silicon-on-insulator process that minimizes parasitic leakage currents at elevated temperature. Variance in device parameters are managed to maintain high performance over a wide temperature range. Layout and packaging considerations that would affect long term reliability are addressed. The amplifier is well characterized above 200°C and attains much higher performance than amplifiers not optimized for high temperature operation. Comprehensive reliability testing over temperature has been completed.

Low Temperature, Fast Sintering of Micro-Scale Silver Paste for Die Attach for 300°C Applications

2015 ◽  
Vol 2015 (1) ◽  
pp. 000654-000660 ◽  
Author(s):  
Fang Yu ◽  
R. Wayne Johnson ◽  
Michael C. Hamilton
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
High Performance ◽  
High Reliability ◽  
Sintering Process ◽  
Power Devices ◽  
C Storage ◽  
Die Attach ◽  
Increasing Demand ◽  
High Lead

With an increasing demand for SiC and GaN high power devices that operate at high temperature, traditional solder materials are reaching their limitations in performance. In addition, there is a strong desire to eliminate high lead containing solders in Si power device packaging for use over conventional temperature range. Low temperature Ag sintering technology is a promising method for high performance lead-free die attachment. In a previous study, a pressureless sintering process and suitable metallization were demonstrated to provide high reliability die attach by using micro-size Ag sintering. The resulting die attach layer had approximately 30% porosity. In this work, a low temperature pressure-assisted fast sintering process was examined. The porosity was decreased from 30% to 15% with application of a low pressure (7.6MPa) during a one minute sintering process. The shear strength for a 3 mm × 3 mm die was 70 MPa and the 8 mm × 8 mm die could not be sheared off due to a 100 kg shear module force limit. Both the Ag and Au metallization (die and substrate) were studied. Furthermore, a new substrate metallization combination was found that allows the use of Au thick film metallized substrates. High temperature (300 °C) storage tests for up to 2000 hours aging were conducted and results are presented.

A super-thermostable, flexible supercapacitor for ultralight and high performance devices

2020 ◽  
Vol 8 (2) ◽  
pp. 532-542 ◽  
Author(s):  
Dong Won Kim ◽  
Sung Mi Jung ◽  
Hyun Young Jung
Keyword(s):  
High Temperature ◽  
Energy Density ◽  
Polymer Composite ◽  
High Performance ◽  
Composite Electrolytes ◽  
Graphene Aerogel ◽  
High Capacitance ◽  
Flexible Supercapacitor ◽  
Flexible Supercapacitors ◽  
High Temperature Operation

High-temperature operation and flexible supercapacitors are designed from graphene aerogel electrodes and IL-FSN based polymer composite electrolytes, achieving a high capacitance of 1007 F g−1 and an energy density of 1134 Wh kg−1 at 200 °C.

Development of Electrode Structure for High Performance Fuel Cell Using CAE

2010 ◽  
Author(s):  
Joji Tomiyasu ◽  
Takashi Harada ◽  
Makoto Fujiuchi ◽  
Takaji Inamuro ◽  
Shiaki Hyodo ◽  
...  
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
High Performance ◽  
Flow Simulation ◽  
Gas Diffusion ◽  
Polymer Electrolyte Fuel Cell ◽  
Structural Factors ◽  
Electrode Structure ◽  
Cold Starting ◽  
High Temperature Operation

Cold starting performance and high temperature operation are current issues in the development of high performance polymer electrolyte fuel cell (PEFC) electrodes. Although excess water must be removed to improve these aspects of electrode performance, it is also important to adopt a structure that prevents the electrodes from drying up. In the face of this conflicting relationship, it is therefore difficult to design an electrode structure with the required properties. For this reason, using technology jointly developed with Kyoto University and Toyota R&D Labs., Inc., the relationship between structural factors and performance was identified by applying a two-phase flow simulation to the complex microstructure of the gas diffusion layer (GDL) to optimize the electrode structure. As a result, an electrode structure was designed that improves high temperature operation while maintaining cold starting performance. The simulation results were then validated by experiments.

scholarly journals Model Development for Threshold Voltage Stability Dependent on High Temperature Operations in Wide-Bandgap GaN-Based HEMT Power Devices

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 658 ◽  
Author(s):  
Huolin Huang ◽  
Feiyu Li ◽  
Zhonghao Sun ◽  
Yaqing Cao
Keyword(s):  
High Temperature ◽  
Analytical Model ◽  
Threshold Voltage ◽  
Computer Aided Design ◽  
Wide Bandgap ◽  
Physical Parameters ◽  
High Electron ◽  
Power Devices ◽  
Operation Condition ◽  
High Temperature Operation

Temperature-dependent threshold voltage (Vth) stability is a significant issue in the practical application of semi-conductor power devices, especially when they are undergoing a repeated high-temperature operation condition. The Vth analytical model and its stability are dependent on high-temperature operations in wide-bandgap gallium nitride (GaN)-based high electron mobility transistor (HEMT) devices that were investigated in this work. The temperature effects on the physical parameters—such as barrier height, conduction band, and polarization charge—were analysed to understand the mechanism of Vth stability. The Vth analytical model under high-temperature operation was then proposed and developed to study the measurement temperatures and repeated rounds dependent on Vth stability. The validity of the model was verified by comparing the theoretical calculation data with the experimental measurement and technology computer-aided design (TCAD) simulation results. This work provides an effective theoretical reference on the Vth stability of power devices in practical, high-temperature applications.

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