Evaluation Method for Performance of SiC Power Module by Electro-Thermal-Anisotropic Stress Coupled Analysis

2018 ◽  
Author(s):  
Mitsuaki Kato ◽  
Akihiro Goryu ◽  
Akira Kano ◽  
Kazuto Takao ◽  
Kenji Hirohata ◽  
...  
Keyword(s):  
Internal Stress ◽  
Electrical Resistance ◽  
Evaluation Method ◽  
Uniaxial Stress ◽  
Electrical Circuit ◽  
Coupled Analysis ◽  
Analysis Method ◽  
Four Point Bending ◽  
Power Modules ◽  
The Relationship

Silicon carbide (SiC) has attracted increasing attention as a material suitable for use with high breakdown voltages and at high temperatures. The effects of residual stress and thermal stress on the electrical properties are therefore a matter of growing concern. To analyze the effects, multi-physics simulation is required. The aim of this study is to present an evaluation method for SiC power modules by electro-thermal-stress coupled analysis. In this analysis, we investigate the relationship among mechanical stress, temperature, and electrical resistance in 4H-SiC MOSFET. To investigate the relationship, we used a four-point bending system that is capable of applying uniaxial stress to the SiC device. We prepared two kinds of test specimens with the uniaxial stress direction of four-point bending coinciding with the 〈112̄0〉 and 〈11̄00〉 direction of SiC. To associate the four-point bending load with the stress components in the SiC device, the four-point bending test was simulated by the finite element method. Tensile or compressive load was applied to two types of test specimens, and the internal stress of the SiC device was determined. To determine the internal stress during operation and mounting, the simple module model was also simulated by the structural analysis method. The internal stress was simulated from mounting temperature to the operating temperature. An electrical circuit and thermal circuit were constructed for the DC-DC converter in the above-described module for the coupled analysis method. The relationship among mechanical stress, temperature, and electrical resistance was incorporated into the additional resistance of the MOSFET in the electrical circuit. When an isotropic stress from −500 to 1400 MPa was applied with the SiC under the oxide film in the one parallel DC-DC converter, the change in the power conversion efficiency was about 0.16%. This indicates that our proposed method is a useful simulation method for SiC power modules.

Evaluation Method for Mechanical Stress Dependence of the Electrical Characteristics of SiC MOSFET for Electro-Thermal-Structural Coupled Analysis

2017 ◽  
Author(s):  
Akihiro Goryu ◽  
Mitsuaki Kato ◽  
Akira Kano ◽  
Satoshi Izumi ◽  
Kenji Hirohata
Keyword(s):  
Tensile Stress ◽  
Mechanical Stress ◽  
Evaluation Method ◽  
Metal Plate ◽  
Experimental Results ◽  
Stress Factors ◽  
Power Device ◽  
Coupled Analysis ◽  
Electrical Characteristics ◽  
Four Point Bending

Power semiconductor devices such as MOSFET/IGBT and PiN diodes are widely used as basic components for supporting infrastructure in the field of electronics, including in power conversion, industrial equipment, railways, and automobiles. Recently, increasing attention has been paid to silicon carbide (SiC) as a wide-band-gap semiconductor suitable for use in power devices with low loss and high breakdown voltage. However, basic knowledge of the material properties and reliability of SiC devices, and particularly the influence of mechanical stress on device characteristics, is still incomplete. In this paper, we evaluated the effect of mechanical stress on the electrical characteristics of SiC devices. In order to investigate the effect of stress on the SiC device characteristic, we propose a simple evaluation method using four-point bending, which is a classical method capable of applying uniaxial stress to a device. With this method, we evaluated the stress in a SiC device using residual stress measurement by Raman spectroscopy and stress simulation based on the finite element method. Our proposed experimental method is as follows. First, the SiC device was bonded with AuGe solder to a metal plate [phosphor bronze; Young’s modulus: 105 GPa; Poisson’s ratio: 0.33; dimensions: 100 mm (W) × 12 mm (L) × 2 mm (T)], and aluminum wire (wire radius: 200 μm) was also bonded to the device. Second, the prepared device was placed on the specially designed four-point bending apparatus for mechanical stress experiments. Finally, the sample was bent in compression or tension in the in-plane direction by the four-point system. The SiC device was subjected to compression or tensile stress via the metal plate. The electrical characteristics of the SiC-MOSFET were measured with a curve tracer in our proposed system. Id−Vds characteristics changed linearly as stress was applied to the device. As a result, the on-resistance was increased by 7.6% by applying a tensile stress of 300 MPa and was decreased by 1.0% by applying a compressive stress of 100 MPa at room temperature, respectively. A power device circuit with multiple chips was also simulated by SPICE based on the experimental results to confirm the effects of stress on SiC devices in a power module. Simulated MOSFET model contains stress factors obtained from experimental results. The circuit was simulated by electro-thermal coupled analysis using a one-dimensional model of the electric circuit and thermal circuit constructed in SPICE. The results show that the proposed method is powerful simulation method for power device design.

scholarly journals A Compact Eight-terminal Piezotransducer for Stress Measurements in Silicon

2017 ◽  
Vol 12 (1) ◽  
pp. 24-32
Author(s):  
Jose L. Ramirez ◽  
Fabiano Fruett
Keyword(s):  
Stress State ◽  
Integrated Circuits ◽  
Carrier Mobility ◽  
Structural Integrity ◽  
Uniaxial Stress ◽  
Silicon Chips ◽  
Four Point Bending ◽  
Stress Sensing ◽  
The Relationship

Deformations in the crystalline structure have an important impact in electric characteristics of the semiconductors, like carrier mobility and concentration. Since mechanical stress and strain are related, an induced stress in silicon chips compromise the performance and structural integrity of Integrated Circuits (ICs). Reason why stress sensing devices are becoming important tools to detect and correct stress related problems, improving the performance and yield of ICs. This work shows the design and characterization of an Eight Terminals Silicon Piezotransduzer (8TSP), a stress sensor device based on the piezoresistive effect and designed to estimate the stress state over the (100) silicon surface. The multi-terminal device integrates a resistor rosette in a single octagonal plate, allowing to change the bias direction and to take measure in different orientations, the relationship between those observations can be used to estimate both direction and magnitude of the stress in a certain area. In order to characterize the device, a four-point-bending apparatus using a circular substrate has to be designed to have control of both magnitude and direction of the applied uniaxial stress. The device was attached to a disk and stress was applied in the main crystallographic directions to observe the piezoresistance characteristics and calibrate the sensor. We applied stress in some other directions and the stress behavior fit the predicted by the theory. Those results confirm that the 8TPS can be used to find the stress state over the surface of a silicon chip.

ÖRGÜTLERDE ÖRGÜTSEL BOLLUĞUN GİRİŞİMSEL ORYANTASYON ÜZERİNDEKİ ETKİSİ

2016 ◽  
Vol 4 (3) ◽  
Author(s):  
Nurdan Gürkan ◽  
Ahmet Ferda Çakmak
Keyword(s):  
Corporate Governance ◽  
Data Analysis ◽  
Panel Data ◽  
Strategic Management ◽  
Significant Relationship ◽  
Entrepreneurial Orientation ◽  
Panel Data Analysis ◽  
Organizational Slack ◽  
Analysis Method ◽  
The Relationship

The concept of entrepreneurial orientation, which emerges with the development of strategic management, refers to entrepreneurship orientations of businesses. The businesses need resources in other words organizational slack in order to develop their entrepreneurial trends. The organizational slack consists of three slack type. These slack types are available slack, recoverable slack and potential slack. The purpose of this study is to examine whether organizational slack in the businesses has an effect on entrepreneurial orientation. The relationship between organizational slack and entrepreneurial orientation was investigated through 20 companies that were traded in Borsa Istanbul Corporate Governance Index for 2010-2014 period using panel data analysis method. The results of the study indicate the existence of a statistically significant relationship between and the available slack and the recoverable slack with the entrepreneurial orientation in the businesses. According to findings; there was no statistically significant relationship between potential slack and entrepreneurial orientation.

PENGARUH KUALITAS PRODUK DAN KUALITAS PELAYANAN TERHADAP PENINGKATAN KEPUASAN DAN LOYALITAS PELANGGAN PERUSAHAAN DAERAH AIR MINUM (PDAM) KOTA MAKASSAR

2019 ◽  
Vol 3 (2) ◽  
pp. 228-244 ◽  
Author(s):  
Muhammad Rezha Pahlawan ◽  
Nurlia Nurlia ◽  
Abdul Rahman Laba ◽  
Erlina Pakki ◽  
Hardiyono Hardiyono
Keyword(s):  
Customer Satisfaction ◽  
Service Quality ◽  
Product Quality ◽  
Customer Loyalty ◽  
Indirect Effects ◽  
Analysis Method ◽  
Water Company ◽  
The Relationship ◽  
Intervening Variables ◽  
Customer Satisfaction And Loyalty

This study aims to determine the effect of Product Quality and Service Quality on Increasing Customer Satisfaction and Loyalty in Makassar Municipal Water Company (PDAM) both directly and through intervening variables or indirect effects. This study uses a quantitative approach conducted with the aim to explain the position of the variables studied and the relationship between one variable with another variable. This research will explain the causal relationship between variables through hypothesis testing. In this study, the analysis method used is path analysis using the SmartPLS program. The results of this study found that directly the product quality had a positive and significant effect on customer satisfaction, service quality had a positive and significant effect on customer satisfaction, product quality had a positive and significant effect on customer loyalty, service quality had a positive and not significant effect on customer loyalty, customer satisfaction positive and significant effect on customer loyalty. The indirect effect of this research is product quality has a positive and significant effect on customer loyalty if mediated by customer satisfaction. Service quality also has a positive and significant effect on customer loyalty if mediated by customer satisfaction.

Optimization of Pan Coating Process for Increased Efficiency of Controlled-Release Urea Fertilizer

2021 ◽  
Vol 57 (4) ◽  
pp. 333-342
Author(s):  
Trung Huu Nguyen ◽  
Tran Nguyen Minh An ◽  
Mahboob Alam ◽  
Duc Hoai Tran ◽  
Nghi Tran ◽  
...  
Keyword(s):  
Controlled Release ◽  
Layer Thickness ◽  
Release Time ◽  
Coating Process ◽  
Analysis Method ◽  
Sauter Mean Diameter ◽  
Urea Fertilizer ◽  
The Relationship ◽  
Central Composite ◽  
Controlled Release Urea

The goal of the research is to develop an experimental mathematical model of pan coating process effect on the biodegradable polymer and to determine optimal process parameters. The polymer solution was conducted with phosphated di-starch phosphate, polyvinyl alcohol, and polyacrylic acid and performed as material coating for the controlled-release urea fertilizer. The image analysis method has been used to determine the particle size distribution, Sauter mean diameter of the particle and layer thickness that is novel. The central composite rotatable design has been selected to determine the regression models of the process, which described the relationship between two objective variables as layer thickness, release time with angle of pan, spray flow, and coating time. The statistical analysis results indicate the fitness of model.

Corrosion Problems in a Refinery Diethanolamine System

CORROSION ◽  
1960 ◽  
Vol 16 (10) ◽  
pp. 503t-506t ◽  
Author(s):  
KENNETH L. MOORE
Keyword(s):  
Hydrogen Sulfide ◽  
Electrical Resistance ◽  
System Operation ◽  
Measuring Device ◽  
Acid Gas ◽  
Gas Streams ◽  
The Rich ◽  
The Relationship ◽  
Refinery Gas ◽  
Propane Butane

Abstract Various corrosion problems are described which have occurred in a large diethanolamine (DEA) system that removes hydrogen sulfide from refinery gas streams and a liquid propane-butane stream. These include reboiler corrosion, rich DEA corrosion, stress corrosion cracking, and corrosion-erosion. The effect of the problems on system operation is discussed, as well as the means of minimizing the problems. Electrical resistance measuring device data indicate the importance of keeping the solution loading below 0.34 mol of acid gas (H2S + CO2) per mol of DEA to minimize the corrosion in the rich DEA. Data from this source also show the relationship between general reboiler corrosion and solution contamination. 8.4.3

scholarly journals The Relationship Between Tumor Budding, Tumor Microenvironment, and Survival in Patients with Primary Operable Colorectal Cancer

2019 ◽  
Vol 26 (13) ◽  
pp. 4397-4404 ◽  
Author(s):  
Hester C. van Wyk ◽  
Antonia Roseweir ◽  
Peter Alexander ◽  
James H. Park ◽  
Paul G. Horgan ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Tumor Microenvironment ◽  
Evaluation Method ◽  
Venous Invasion ◽  
Staging System ◽  
Consensus Conference ◽  
Tumor Budding ◽  
Inflammatory Cell Infiltrate ◽  
Cancer Specific Survival ◽  
The Relationship

Abstract Background Tumor budding is an independent prognostic factor in colorectal cancer (CRC) and has recently been well-defined by the International Tumour Budding Consensus Conference (ITBCC). Objective The aim of the present study was to use the ITBCC budding evaluation method to examine the relationship between tumor budding, tumor factors, tumor microenvironment, and survival in patients with primary operable CRC. Methods Hematoxylin and eosin-stained slides of 952 CRC patients diagnosed between 1997 and 2007 were evaluated for tumor budding according to the ITBCC criteria. The tumor microenvironment was evaluated using tumor stroma percentage (TSP) and Klintrup–Makinen (KM) grade to assess the tumor inflammatory cell infiltrate. Results High budding (n = 268, 28%) was significantly associated with TNM stage (p < 0.001), competent mismatch repair (MMR; p < 0.05), venous invasion (p < 0.001), weak KM grade (p < 0.001), high TSP (p < 0.001), and reduced cancer-specific survival (CSS) (hazard ratio 8.68, 95% confidence interval 6.30–11.97; p < 0.001). Tumor budding effectively stratifies CSS stage T1 through to T4 (all p < 0.05) independent of associated factors. Conclusions Tumor budding effectively stratifies patients’ survival in primary operable CRC independent of other phenotypic features. In particular, the combination of T stage and budding should form the basis of a new staging system for primary operable CRC.

Evidential Study of Relationship between Flexible Drift of Fuel Nozzle Performance and Hot-End Failure of X Engine

2014 ◽  
Vol 651-653 ◽  
pp. 724-728
Author(s):  
Yong Gang Xu ◽  
Qiang Wang
Keyword(s):  
Abrupt Change ◽  
Initial Period ◽  
Flow Property ◽  
Analysis Method ◽  
Comparison Analysis ◽  
Fuel Nozzle ◽  
Converging Flow ◽  
The Relationship ◽  
Relative Scarcity ◽  
Engine Start

By means of the fountain-convergence analysis method of FRRU (Flow Resistance-Rigidity Uniformity) index defined by the author, evidential comparison analysis study has been made to the relationship between flexible drift of flow performance of WTD (Weight Type Distributor) valves of fuel nozzles of X engine and hot-end failures of X engine. The results show that during the initial period of engine start, because of the relative scarcity of air in the combustor, a convergence characteristic, due to its converging flow property ofmultiple to one, can lead to such hot-end failures as turbine blade fusion break which is characterized byabrupt change, while a fountain characteristic, due to its diffusing flow property ofone tomultiple, cannot result in any hot-end failures.

Evaluation of Product Preference Using Virtual Prototyping: Case Study of an Automobile Interior

2002 ◽  
Vol 46 (6) ◽  
pp. 740-744 ◽  
Author(s):  
Chul Woo Kim ◽  
Jungchul Park ◽  
Myung Hwan Yun ◽  
Sung H. Han ◽  
Hee-Dong Ko
Keyword(s):  
Virtual Reality ◽  
Interior Design ◽  
Evaluation Method ◽  
Product Evaluation ◽  
Steering Wheel ◽  
Subjective Impression ◽  
Design Elements ◽  
Design Alternatives ◽  
Virtual Prototypes ◽  
The Relationship

The objective of this study was to develop a product evaluation method applicable to virtual prototypes and to apply the method to automobile interior design. Considering that virtual reality-based product prototypes could represent design alternatives comparable to physical prototypes, prototypes developed in virtual reality environments were employed as design alternatives. After a procedure to evaluate virtual prototypes was developed specifically for a virtual reality environment, the procedure was applied to the problem of automobile interior design. 34 subjects evaluated 32 different virtual prototypes generated from the combination of design element variations. Four categories of subjective impression were used to evaluate the 32 virtual prototypes: luxuriousness, comfort, harmoniousness, and controllability. ANOVA and multiple linear regression analysis were performed to specify design elements critical to customer preference and to interpret the relationship between design elements and subjective impressions. As the result, the shapes of frontal area including crash pad and center fascia, door trim and steering wheel were selected as important variables related to subjective impressions. The proposed evaluation method for virtual prototypes could be utilized as an alternative way of identifying the relationship between subjective impressions and design elements.

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