Analysis of Novel Packaging Techniques for High Power Electronics in SiC

2007 ◽  
Vol 556-557 ◽  
pp. 971-974
Author(s):  
S.J. Rashid ◽  
C. Mark Johnson ◽  
F. Udrea ◽  
Andrej Mihaila ◽  
G. Amaratunga ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Copper Substrate ◽  
Mechanical Analysis ◽  
Element Analysis ◽  
Effective Resistivity ◽  
Assembly Result ◽  
Full Load Operation ◽  
Expansion Coefficients ◽  
Device Operation ◽  
A Current

A novel high temperature wire bondless packaging technique is numerically investigated in this paper. Extraction of device effective resistivity with temperature from numerical characteristics of 1.2kV 4H-SiC MOSFETs at a current density of 400A/cm2 have demonstrated a T−2 temperature dependence. Electro-thermal finite element analysis (FEA) of 1.2kV 4H-SiC MOSFETs sandwiched between two etched direct-bonded-copper substrate tiles has been performed. The thermal resistance of the ceramic sandwich package shows a 75% reduction in thermal resistance compared to conventional wire bonded assemblies. Mechanical analysis of the assembly has been used to investigate the residual stresses in the SiC dies at room temperature, which are then alleviated at higher temperatures during device operation. Mismatch of the expansion coefficients of the auxiliary materials in the assembly result in elevated stresses at full load operation, however these are well below the tensile strength of the respective materials and hence do not compromise the mechanical integrity of the package.

scholarly journals Mechanical analysis of prosthetic bars and dental implants in 3 and 4 implant-supported overdenture protocols using finite element analysis

2021 ◽  
Author(s):  
Luiz Bassi Junior ◽  
Rafael Oliveira de Souza Silva ◽  
Victor Hugo Dias dos Santos ◽  
Abner da Rocha Lourenço ◽  
Paulo Vinicius Trevizoli ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dental Implants ◽  
Mechanical Analysis ◽  
Element Analysis

scholarly journals Organizing Cells Within Non-Periodic Microarchitectured Materials That Achieve Graded Thermal Expansions

2015 ◽  
Author(s):  
Jonathan B. Hopkins ◽  
Lucas A. Shaw ◽  
Todd H. Weisgraber ◽  
George R. Farquar ◽  
Christopher D. Harvey ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Thermal Expansion ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Element Analysis ◽  
Thermal Expansion Coefficients ◽  
Large Lattice ◽  
Unit Cells ◽  
Expansion Coefficients ◽  
Bulk Behavior

The aim of this paper is to introduce an approach for optimally organizing a variety of different unit cell designs within a large lattice such that the bulk behavior of the lattice exhibits a desired Young’s modulus with a graded change in thermal expansion over its geometry. This lattice, called a graded microarchitectured material, can be sandwiched between two other materials with different thermal expansion coefficients to accommodate their different expansions or contractions caused by changing temperature while achieving a desired uniform stiffness. First, this paper provides the theory necessary to calculate the thermal expansion and Young’s modulus of large multi-material lattices that consist of periodic (i.e., repeating) unit cells of the same design. Then it introduces the theory for calculating the graded thermal expansions of a large multimaterial lattice that consists of non-periodic unit cells of different designs. An approach is then provided for optimally designing and organizing different unit cells within a lattice such that both of its ends achieve the same thermal expansion as the two materials between which the lattice is sandwiched. A MATLAB tool is used to generate images of the undeformed and deformed lattices to verify their behavior and various examples are provided as case studies. The theory provided is also verified and validated using finite element analysis and experimentation.

scholarly journals Replacement of metallic parts for polymer composite materials in motorcycle oil pumps

2016 ◽  
Vol 36 (2) ◽  
pp. 149-160 ◽  
Author(s):  
Sandro Donnini Mancini ◽  
Antídio de Oliveira Santos Neto ◽  
Maria Odila Hilário Cioffi ◽  
Eduardo Carlos Bianchi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Glass Transition ◽  
Glass Fiber ◽  
Dynamic Mechanical Analysis ◽  
Mechanical Analysis ◽  
Neutral Medium ◽  
Element Analysis ◽  
Dynamic Mechanical ◽  
Oil Pump

A feasibility study was conducted to determine the use of polyphthalamide/glass-fiber and polyphthalamide/glass-fiber/polytetrafluoroethylene-based composites as substitutes for aluminum and steel, respectively, in the production of motorcycle oil pump parts (housing, shaft/inner gerotor and outer gerotor). New and used (80,000 km) oil pumps were subjected to performance tests, whose results indicated that the pressure and temperature of the used pump reached a maximum of 1.8 bar and 93℃, respectively. Thermogravimetric analysis indicated that the materials are stable at the maximum operating temperature, which is 20℃ lower than the minimum glass transition temperature obtained by dynamic mechanical analysis for both materials at the analyzed frequencies (defined after calculations based on rotations in neutral, medium and high gear). The pressure value was multiplied by a safety factor of at least 1.6 (i.e., 3 bar), which was used as input for a finite element analysis of the parts, as well as the elasticity modulus at glass transition temperatures obtained by dynamic mechanical analysis. The finite element analysis indicated that the von Mises stresses to which the composite parts were subjected are 7 to 50 times lower than those the materials can withstand. The results suggest that it is feasible to manufacture motorcycle oil pump parts with these composites.

scholarly journals Mechanical analysis on design parameters for adhesion bridge. Part 2 Finite element analysis of infuluence of thickness, shape and materials on pealing loads.

1986 ◽  
Vol 30 (4) ◽  
pp. 920-928
Author(s):  
Yoshinobu Maeda ◽  
Masafumi Mori ◽  
Sadami Tsutsumi ◽  
Toshihiro Chinzaka ◽  
Masataka Minoura ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanical Analysis ◽  
Design Parameters ◽  
Element Analysis

scholarly journals Fabrication of Optimally Micro-Textured Copper Substrates by Plasma Printing for Plastic Mold Packaging

2020 ◽  
Vol 14 (2) ◽  
pp. 200-207 ◽  
Author(s):  
Tatsuhiko Aizawa ◽  
Yasuo Saito ◽  
Hideharu Hasegawa ◽  
Kenji Wasa ◽  
◽  
...  
Keyword(s):  
Stress Distribution ◽  
Copper Substrate ◽  
Three Dimensional ◽  
Picosecond Laser ◽  
Numerical Control ◽  
Uniform Stress ◽  
Element Analysis ◽  
Micro Grooving ◽  
Plastic Mold ◽  
Screen Printed

Micro-embossing using plasma printed micro-punch was proposed to form micro-groove textures into the copper substrate for plastic packaging of hollowed GaN HEMT-chips. In particular, the micro-groove network on the copper substrate was optimized to attain uniform stress distribution with maximum stress level being as low as possible. Three-dimensional finite element analysis was employed to investigate the optimum micro-grooving texture-topology and to attain the uniform stress distribution on the joined interface between the plastic mold and the textured copper substrate. Thereafter, plasma printing was utilized to fabricate the micro-punch for micro-embossing of the micro-grooving network into the copper substrate as a designed optimum micro-texture. This plasma printing mainly consisted of three steps. Two-dimensional micro-pattern was screen-printed onto the AISI316 die surface as a negative pattern of the optimum CAD data. The screen-printed die was plasma nitrided at 673 K for 14.4 ks at 70 Pa under the hydrogen-nitrogen mixture for selective nitrogen supersaturation onto the unprinted die surfaces. A micro-punch was developed by mechanically removing the printed parts of die material. Then, fine computer numerical control (CNC) stamping was used to yield the micro-embossed copper substrate specimens. Twelve micro-textured substrates were molded into packaged specimens by plastic molding. Finally, gross leak testing was employed to evaluate the integrity of the joined interface. The takt time required to yield the micro-grooved copper substrate by the present method was compared to the picosecond laser micro-grooving; the former showed high productivity based on this parameter.

Thermal and Mechanical Characterization of High Power GaN Packages

2011 ◽  
Vol 2011 (1) ◽  
pp. 000361-000366
Author(s):  
Don Willis ◽  
Gary Gu ◽  
Daniel Jin ◽  
Rob Dry
Keyword(s):  
Thermal Performance ◽  
High Power ◽  
Mechanical Analysis ◽  
Heat Spreader ◽  
Element Analysis ◽  
Die Attach ◽  
Viable Solution ◽  
Alternative Approach ◽  
Thermal Improvement ◽  
Multiple Devices

The typical package available for high power GaN application has the devices directly attached onto a metal flange, which could contribute significantly to the overall thermal resistance. This paper discusses an alternative approach to packaging both single and multiple devices through a heat spreader, which could potentially improve thermal performance and bring significant benefits to assembly in yields and cost. However, the heat spreader could also introduce significant CTE mis-match and potential concerns in reliability. Nonlinear 3D finite element analysis (FEA) was conducted to characterize the thermal performance and evaluate mechanical/reliability concerns. Thermal modeling considered single and multiple die applications, and the results show13–15% thermal improvement with the copper heat spreader. Mechanical analysis focused on the thermal loads of the die attach and solder reflow processes. It reveals that the die attach process is more critical as shown in the higher stress due to higher thermal load, but stress/strain levels appear to be acceptable. Thus, this alternative approach could be a viable solution.

Design and analysis of a high speed double-sided axial flux permanent magnet motor suspended vertically by magnetic bearings

2020 ◽  
pp. 1-15
Author(s):  
Ömer Faruk Güney ◽  
Ahmet Çelik ◽  
Ahmet Fevzi Bozkurt ◽  
Kadir Erkan
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Permanent Magnets ◽  
Mechanical Analysis ◽  
Magnetic Bearings ◽  
Permanent Magnet Motor ◽  
Axial Flux ◽  
Element Analysis ◽  
Shaft System ◽  
Rotor Disk

This paper presents the electromagnetic and mechanical analysis of an axial flux permanent magnet (AFPM) motor for high speed (12000 rpm) rotor which is vertically suspended by magnetic bearings. In the analysis, a prototype AFPM motor with a double-sided rotor and a coreless stator between the rotors are considered. Firstly, electromagnetic analysis of the motor is carried out by using magnetic equivalent circuit method. Then, the rotor disk thickness is determined based on a rotor axial displacement due to the attractive force between the permanent magnets placed on opposite rotor disks. Hereafter, an analytical solution is carried out to determine the natural frequencies of the rotor-shaft system. Finally, 3D finite element analysis (FEA) is carried out to verify the analytical results and some experimental results are given to verify the analytical and numerical results and prove the stable high-speed operation.

Finite Element Analysis of the Effect of Particle Shape on the Thermal Conductivity in Diamond/Cu Composites

2014 ◽  
Vol 788 ◽  
pp. 689-692
Author(s):  
Hong Guo ◽  
Yuan Yuan Han ◽  
Xi Min Zhang ◽  
Fa Zhang Yin ◽  
Ye Ming Fan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Resistance ◽  
Particle Shape ◽  
Finite Element Calculation ◽  
Element Calculation ◽  
Element Analysis ◽  
Result Show

The effect of diamond shape on the thermal conductivity of diamond/Cu composites was studied by combine finite element method with the tests. The finite element result show that the thermal conductivity of the hexoctahedron diamond/Cu composites and the square diamond/Cu composites is 819 W/m·K and 1013 W/m·K respectively. And the testing results indicate that the thermal conductivity of the single hexoctahedron diamond/Cu composites and the hexoctahedron mixed with the square diamond/Cu composites is 659W/m·K and 720 W/m·K respectively. The testing results consist with the finite element calculation. Under the same circumstances, more {100} faces can bring in less overall thermal resistance in the composites thus improve the thermal conductivity of the composites. The results show that using square diamond particles helps to improve the thermal conductivity of diamond/Cu composites.

Finite element analysis of fiber optic embedded in thermal spray coating

2017 ◽  
Vol 29 (5) ◽  
pp. 896-904 ◽  
Author(s):  
Duo Yi ◽  
Min Zhang ◽  
Lijuan Gu ◽  
Jianming Yang ◽  
Wenhui Yu
Keyword(s):  
Finite Element ◽  
Refractive Index ◽  
Thermal Spray ◽  
Composite Structure ◽  
Fiber Optic ◽  
Spray Coating ◽  
Element Model ◽  
Thermal Spray Coating ◽  
Mechanical Analysis ◽  
Element Analysis

This study aims to evaluate the thermomechanical behavior of a new composite structure using finite element method. The composite structure consists of the substrate and the thermal spray coating with embedded fiber optic. The temperature evolution of the composite estimated by the finite element model shows good agreement with the experimental recording, which confirms the justifiability of model initialization, and then, the thermal results are applied for the following mechanical analysis. The stress distribution and the variation in refractive index of the embedded fiber are investigated. The results show that the stress level suffered by the embedded fiber is much lower than the yield strength, and the variation in refractive index of the embedded fiber has an insignificant effect on optical transmission, which ensures a good embedding quality of the fiber optic.

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