scholarly journals Design and Manufacturing of a Double-Side Cooled, SiC based, High Temperature Inverter Leg

2014 ◽  
Vol 2014 (HITEC) ◽  
pp. 000372-000377 ◽  
Author(s):  
Raphaël RIVA ◽  
Cyril BUTTAY ◽  
Marie-Laure LOCATELLI ◽  
Vincent BLEY ◽  
Bruno ALLARD
Keyword(s):  
High Temperature ◽  
Dielectric Material ◽  
Heat Extraction ◽  
Power Devices ◽  
Power Module ◽  
Ceramic Substrates ◽  
Design And Manufacturing ◽  
Temperature Capability ◽  
Silver Sintering ◽  
Very High

In this paper, we present a small (25×25×3 mm3) power module that integrates two silicon-carbide (SiC) JFETs to form an inverter leg. This module has a “sandwich” structure, i.e. the power devices are placed between two ceramic substrates, allowing for heat extraction from both sides of the dies. All interconnects are made by silver sintering, which offers a very high temperature capability (the melting point of pure silver being 961 °C). The risk of silver migration is assessed, and we show that Parylene-HT, a dielectric material that can sustain more than 300 °C, can completely coat the module, providing adequate protection.

First Demonstration of High Temperature SiC CMOS Gate Driver in Bridge Leg for Hybrid Power Module Application

2018 ◽  
Vol 924 ◽  
pp. 854-857
Author(s):  
Ming Hung Weng ◽  
Muhammad I. Idris ◽  
S. Wright ◽  
David T. Clark ◽  
R.A.R. Young ◽  
...  
Keyword(s):  
High Temperature ◽  
Integrated Circuits ◽  
Initial Increase ◽  
Reliability Test ◽  
Power Devices ◽  
Power Module ◽  
Hybrid Power ◽  
Gate Driver ◽  
Passive Circuit

A high-temperature silicon carbide power module using CMOS gate drive technology and discrete power devices is presented. The power module was aged at 200V and 300 °C for 3,000 hours in a long-term reliability test. After the initial increase, the variation in the rise time of the module is 27% (49.63ns@1,000h compared to 63.1ns@3,000h), whilst the fall time increases by 54.3% (62.92ns@1,000h compared to 97.1ns@3,000h). The unique assembly enables the integrated circuits of CMOS logic with passive circuit elements capable of operation at temperatures of 300°C and beyond.

Characteristics and aging of SiC MOSFETs operated at very high temperatures

2014 ◽  
Vol 1693 ◽  
Author(s):  
Dean P. Hamilton ◽  
Michael R. Jennings ◽  
Craig A. Fisher ◽  
Yogesh K. Sharma ◽  
Stephen J. York ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Threshold Voltage ◽  
Thermal Aging ◽  
Ohmic Contacts ◽  
Stress Tests ◽  
Temperature Capability ◽  
Temperature Constant ◽  
Voltage Management ◽  
Very High

ABSTRACTSilicon carbide power devices are purported to be capable of operating at very high temperatures. Current commercially available SiC MOSFETs from a number of manufacturers have been evaluated to understand and quantify the aging processes and temperature dependencies that occur when operated up to 350°C. High temperature constant positive bias stress tests demonstrated a two times increase in threshold voltage from the original value for some device types, which was maintained indefinitely but could be corrected with a long negative gate bias. The threshold voltages were found to decrease close to zero and the on-state resistances increased quite linearly to approximately five or six times their room temperature values. Long term thermal aging of the dies appears to demonstrate possible degradation of the ohmic contacts. This appears as a rectifying response in the I-V curves at low drain-source bias. The high temperature capability of the latest generations of these devices has been proven independently; provided that threshold voltage management is implemented, the devices are capable of being operated and are free from the effects of thermal aging for at least 70 hours cumulative at 300°C.

Precise Chip Joint Method with Sub-micron Au Particle for High-density SiC Power Module Operating at High Temperature

2013 ◽  
Vol 2013 (HITEN) ◽  
pp. 000254-000259 ◽  
Author(s):  
Fumiki Kato ◽  
Fengqun Lang ◽  
Simanjorang Rejeki ◽  
Hiroshi Nakagawa ◽  
Hiroshi Yamaguchi ◽  
...  
Keyword(s):  
Shear Strength ◽  
High Temperature ◽  
Flip Chip ◽  
Stress Test ◽  
High Density ◽  
Cathode Side ◽  
Module Structure ◽  
Power Devices ◽  
Power Module ◽  
Joint Method

In this work, a novel precise chip joint method using sub-micron Au particle for high-density silicon carbide (SiC) power module operating at high temperature is proposed. A module structure of SiC power devices are sandwiched between two silicon nitride-active metal brazed copper (SiN-AMC) circuit boards. To make a precise position and height control of the chip bonding, the top side (gate/source or anode pad side) of SiC power devices are flip-chip bonded to circuit electrodes using sub-micron Au particle with low temperature (250°C) and pressure-less sintering. The accuracy of the bonding position of chips was less than 10 μm and the accuracy of the height after bonding chips was less than 15 μm. Mechanical shear fatigue tests for flip-chip bonded SiC Schottky barrier diode (SBD) were carried out. As a result, initial shear strength of the joint was 36 MPa. The shear strength of 43 MPa is obtained after storage life test (500 hours at 250°C), and also 35 MPa is obtained even after thermal cycle stress test (1000 cycles between −40°C and 250°C). The flip-chip bonding of SiC-JFET is successfully realizedon the substrate without short or open failure electrically. Finally we joint the backside of the SiC-JFET (drain side) and the SiC-SBD (cathode side) to each circuit electrodes at once by means of reflow process with Au-12%Ge solder. The structured sandwich SiC power module was also successfully formed.

Study of the electrical and thermal properties of a silicone elastomer filled with silica for high temperature power device encapsulation

2015 ◽  
Vol 2015 (HiTEN) ◽  
pp. 1-9 ◽  
Author(s):  
E. Sili ◽  
M.L. Locatelli ◽  
M. Bechara ◽  
S. Diaham ◽  
S. Dinculescu
Keyword(s):  
High Temperature ◽  
Temperature Limit ◽  
Silicone Elastomer ◽  
Power Device ◽  
Maximum Temperature ◽  
Power Devices ◽  
Power Module ◽  
Temperature Range ◽  
Dimethyl Siloxane ◽  
Silicone Gels

In order to take the full advantage of the high-temperature SiC and GaN operating power devices, package materials able to withstand high-temperature storage and large thermal cycles are required. However, a survey of the commercially available silicone gels mostly used for power module encapsulation, highlights that this type of materials exhibits a maximum temperature limit for continuous operation of about 260 °C. A slight extension of this temperature range might be obtained by using silicone elastomers with hardness still remaining measurable on the Shore A scale. The aim of this paper is to study a silicone elastomer poly(dimethyl)siloxane (PDMS) with silica fillers, with a specified maximum operating temperature of 275 °C, in order to evaluate its ability for high temperature power device encapsulation. First, the nature and size of the filler microparticles were determined using scanning electron microscopy (SEM) observations coupled with energy dispersive X-ray spectroscopy (EDX) analysis. Second, the results of the thermal and electrical properties of this elastomer over a wide temperature range show that this type of insulating materials presents promising initial properties for the encapsulation of high temperature power devices.

Warpage Evaluation of High-Temperature Sandwich-Structured Power Module for SiC Power Semiconductor Devices

2015 ◽  
Vol 12 (3) ◽  
pp. 153-160 ◽  
Author(s):  
Takeshi Anzai ◽  
Yoshinori Murakami ◽  
Shinji Sato ◽  
Hidekazu Tanisawa ◽  
Kohei Hiyama ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Cycle ◽  
Coefficient Of Thermal Expansion ◽  
Fabrication Process ◽  
Power Module ◽  
Ceramic Substrates ◽  
Soldering Temperature ◽  
Power Semiconductor ◽  
Power Modules ◽  
High Temperature Operation

This article presents a sandwich-structured SiC power module that can be operated at 225°C. The proposed power module has two ceramic substrates that are made of different materials (Si3N4 and Al2O3). The SiC devices are sandwiched between these ceramic substrates. The module also has a baseplate soldered onto the ceramic substrate. Conventional power modules use baseplate materials with a large coefficient of thermal expansion (CTE), for example, Cu (17–18 ppm/°C and Al (23–24 ppm/°C). In the fabrication process, the soldering temperature reaches 450°C because Au-Ge eutectic solder is used. A problem was found in the fabrication process of the module because of the high soldering temperature and CTE mismatches of the components. Furthermore, for high-temperature operation, a thermal cycle of −40°C to 250°C will be needed to ensure reliability and it is important to decrease the warpage of the module during the thermal cycle. By using stainless steel (CTE: 10 ppm/°C) for the baseplate, the warp-age measured at room temperature was reduced to one-third that of a module using a Cu baseplate. Further, the warpage displacement from 50°C to 250°C was also reduced.

Use of LaB6 for a High Quality, Small Energy Spread Beam in an Electron Velocity Spectrometer

1976 ◽  
Vol 34 ◽  
pp. 534-535 ◽  
Author(s):  
P. E. Batson ◽  
C. H. Chen ◽  
J. Silcox
Keyword(s):  
High Temperature ◽  
Energy Resolution ◽  
Electron Velocity ◽  
Electronic Excitations ◽  
Small Energy ◽  
Small Intensity ◽  
Good Energy ◽  
Spectrometer System ◽  
Electron Energy Loss ◽  
Very High

Electron energy loss experiments combined with microscopy have proven to be a valuable tool for the exploration of the structure of electronic excitations in materials. These types of excitations, however, are difficult to measure because of their small intensity. In a usual situation, the filament of the microscope is run at a very high temperature in order to present as much intensity as possible at the specimen. This results in a degradation of the ultimate energy resolution of the instrument due to thermal broadening of the electron beam.We report here observations and measurements on a new LaB filament in a microscope-velocity spectrometer system. We have found that, in general, we may retain a good energy resolution with intensities comparable to or greater than those available with the very high temperature tungsten filament. We have also explored the energy distribution of this filament.

TEM study of boron additions to cobalt aluminide

1988 ◽  
Vol 46 ◽  
pp. 546-547
Author(s):  
Gerald B. Feldewerth
Keyword(s):  
High Temperature ◽  
Turbine Engines ◽  
Major Drawback ◽  
University Of Missouri ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Wide Range ◽  
Ordered Alloys ◽  
The University ◽  
Very High

In recent years an increasing emphasis has been placed on the study of high temperature intermetallic compounds for possible aerospace applications. One group of interest is the B2 aiuminides. This group of intermetaliics has a very high melting temperature, good high temperature, and excellent specific strength. These qualities make it a candidate for applications such as turbine engines. The B2 aiuminides exist over a wide range of compositions and also have a large solubility for third element substitutional additions, which may allow alloying additions to overcome their major drawback, their brittle nature.One B2 aluminide currently being studied is cobalt aluminide. Optical microscopy of CoAl alloys produced at the University of Missouri-Rolla showed a dramatic decrease in the grain size which affects the yield strength and flow stress of long range ordered alloys, and a change in the grain shape with the addition of 0.5 % boron.

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