Design and Fabrication of SiC based Stepper Motor Driver for High-Temperature Environments

2021 ◽  
Author(s):  
Ashwin Chandwani ◽  
Ayan Mallik ◽  
Akin Akturk ◽  
Weijian Xian ◽  
Usama Khalid ◽  
...  
Keyword(s):  
High Temperature ◽  
Stepper Motor

470 Celsius Packaging System for Silicon Carbide Electronics

2021 ◽  
Vol 2021 (HiTEC) ◽  
pp. 000083-000088
Author(s):  
N. Chiolino ◽  
A. M. Francis ◽  
J. Holmes ◽  
M. Barlow ◽  
C. Perkowski
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Additive Manufacturing ◽  
State Of The Art ◽  
Stepper Motor ◽  
Design Rule ◽  
Design Environment ◽  
Packaging System ◽  
Standard Design ◽  
Packaging Strategy

Abstract High temperature Silicon Carbide (SiC) integrated circuit (IC) processes have enabled devices that operate at >450°C for more than a year. These results have established the need for more advanced and practical packaging strategies. Off the shelf state of the art packages cannot withstand the same high temperatures as the semiconductor can for long periods of time. Packaging SiC die to survive temperatures >450°C, while also maintaining a reasonable packaging strategy that is agile, rapid, and modular, presents new challenges. Presented is a technique for packaging SiC die with a focus on additive manufacturing, modular design scaling, and rugged survivability. This packaging strategy utilizes state of the art Additive Manufacturing (AM) methods, using an nScrypt 3Dn-Tabletop printer, together with stereolithography (SLA) digital light processing (DLP) 3D printing. Ultra-violet (UV) curable ceramic resins are used to create high temperature connectors. A design environment is also described, in which first time correct, interconnect layers are verified in software to reduce the risk of errors. A Ceramic Wiring Board Process Design Kit (CWBPDK) allows the design of single or multiple layers of metal, with fabricated SiC die. This interconnect is verified with standard design rule checking (DRC) and layout vs. schematic (LVS) software. Entire systems in packages can be verified using multiple SiC die. Input and output pins (I/O) are connected to these modules using metal connectors. After design, manufacturing can be performed in just a few days. A system in package for driving a stepper motor was designed and fabricated using this packaging method. The motor actuator design utilizes four separate SiC die. These die contain large JFETs designed for sourcing current in a unipolar stepper motor architecture. This module was placed in a furnace at 470°C and demonstrated functional operation for over 1000 hours. These devices were able to source an average of 30 mA in >400°C temperatures to drive the room temperature stepper motor. A high I/O count, next generation package for discrete SiC chips was also designed using this packaging system. A single large JFET component was soaked for over 100 hours at both 500°C and 800°C. Utilizing Ozark IC’s automated test design environment, several DC and transient variables were captured for both tests and will be presented.

Automation of a Filmscanner for Evaluation of Guinier Films and Applications to Determination of Diffraction Data of Pb2Sr2Ho0.625Ca0.375Cu3O8 and Measurement of Thermal Expansion of GeO2

1991 ◽  
Vol 6 (2) ◽  
pp. 82-84 ◽  
Author(s):  
Jens-Erik Jørgensen
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Light Intensity ◽  
Transmitted Light ◽  
Stepper Motor ◽  
Lattice Constants ◽  
Film Scanner ◽  
Flat Film ◽  
High Temperature Study

AbstractA previously manually operated film comparator used to evaluate Guinier films has been automated as a film scanner of the flat film type. The film movement is controlled by a stepper motor and the intensity of the transmitted light is recorded as a function of position on the film. A personal computer controls the stepper motor and records the measurements of the transmitted light intensity. The data quality is judged from refinements of lattice constants for α-SiO2 and ZrO2. The powder pattern for Pb2Sr2Ho0.625Ca0.375Cu3O8 and a high temperature study of the thermal expansion of GeO2 are presented.

Influence of Thermo-Mechanical Processing on the Microstructure of Beryllia Dispersed Nickel Alloys

1973 ◽  
Vol 31 ◽  
pp. 184-185
Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant
Keyword(s):  
High Temperature ◽  
Nickel Alloys ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Mechanical Processing ◽  
Uniform Dispersion ◽  
Oxide Particles ◽  
Nickel Base

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

Effect of Improved ThO2 Particle Dispersion in Nickel on High-Temperature Strength

1970 ◽  
Vol 28 ◽  
pp. 444-445
Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer
Keyword(s):  
High Temperature ◽  
Metal Matrix ◽  
Oxide Particle ◽  
Oxide Phase ◽  
Dislocation Motion ◽  
Particle Dispersion ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Oxide Particles ◽  
The Stability

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

Albumins as Embedding Media for Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 422-423 ◽  
Author(s):  
J. L. Farrant ◽  
J. D. McLean
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
High Temperature ◽  
Biological Material ◽  
Globular Proteins ◽  
The Past ◽  
Antibody Staining ◽  
Thin Sectioning ◽  
Embedding Medium

For electron microscope techniques such as ferritin-labeled antibody staining it would be advantageous to have available a simple means of thin sectioning biological material without subjecting it to lipid solvents, impregnation with plastic monomers and their subsequent polymerization. With this aim in view we have re-examined the use of protein as an embedding medium. Gelatin which has been used in the past is not very satisfactory both because of its fibrous nature and the high temperature necessary to keep its solutions fluid. We have found that globular proteins such as the serum and egg albumins can be cross-linked so as to yield blocks which are suitable for ultrathin sectioning.

An Environmental Wet Cell For High Voltage Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 18-19
Author(s):  
N.J. Tighe ◽  
H.M. Flower ◽  
P.R. Swann
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Image Quality ◽  
Inelastic Scattering ◽  
High Voltage ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Environmental Cell ◽  
Water Saturated ◽  
High Temperature Gas

A differentially pumped environmental cell has been developed for use in the AEI EM7 million volt microscope. In the initial version the column of gas traversed by the beam was 5.5mm. This permited inclusion of a tilting hot stage in the cell for investigating high temperature gas-specimen reactions. In order to examine specimens in the wet state it was found that a pressure of approximately 400 torr of water saturated helium was needed around the specimen to prevent dehydration. Inelastic scattering by the water resulted in a sharp loss of image quality. Therefore a modified cell with an ‘airgap’ of only 1.5mm has been constructed. The shorter electron path through the gas permits examination of specimens at the necessary pressure of moist helium; the specimen can still be tilted about the side entry rod axis by ±7°C to obtain stereopairs.

Exsolution and inversion in pigeonite from the Whin Sill, Northern England

1978 ◽  
Vol 36 (1) ◽  
pp. 474-475
Author(s):  
P.P.K. Smith
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Homogeneous Nucleation ◽  
Silicate Mineral ◽  
Antiphase Boundaries ◽  
Two Phase ◽  
Primitive Form ◽  
The Core ◽  
Nucleation Mechanisms ◽  
And Inversion

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.

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