scholarly journals Modelling Thermal Resistance of Power Modules Having Solder Voids With Finite Elements

1987 ◽  
Vol 12 (4) ◽  
pp. 239-250 ◽  
Author(s):  
R. A. Tatara
Keyword(s):  
Finite Element ◽  
Heat Conduction ◽  
Finite Elements ◽  
Thermal Resistance ◽  
Computer Program ◽  
Thermal Model ◽  
Three Dimensional ◽  
Power Module ◽  
Power Modules ◽  
Sample Case

A general thermal model to calculate the thermal resistance of a power module having rectangular die and layers has been constructed. The model incorporates a finite element computer program to solve for three-dimensional heat conduction. Effects of voids in the solder regions are included. A sample case is analyzed, and a comparison is made to a recent study.

The Analysis and Design of a Fire Engine Safety Cab Using Finite Element Methods

1977 ◽  
Vol 191 (1) ◽  
pp. 187-193 ◽  
Author(s):  
J. C. Miles ◽  
G. A. Wardill
Keyword(s):  
Finite Element ◽  
Computer Program ◽  
Three Dimensional ◽  
Analysis And Design ◽  
Vehicle Structure ◽  
Collapse Analysis ◽  
Incremental Formulation ◽  
Analysis Computer ◽  
Fire Engine ◽  
Analysis Computer Program

A three dimensional structural collapse analysis computer program is described, and illustrated by reference to a safety vehicle structure analysed and designed using the program. The particular problems of large displacements and material non-linearity are accounted for, and a method of estimating the permanent set which results after impact is described. Based on an incremental formulation of the conventional finite-element method, the computer program is capable of tracing the complete load deflection characteristics of a structure up to and beyond the point of collapse.

Thermal and Electrical Co-Optimization of a Multi-Chip Double-Sided Cooled GaN Module

2021 ◽  
Author(s):  
Hayden Carlton ◽  
John Harris ◽  
Alexis Krone ◽  
David Huitink ◽  
Md Maksudul Hossain ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Heat Removal ◽  
Electrical Characterization ◽  
Thermal Characterization ◽  
Design Strategies ◽  
Power Module ◽  
Parasitic Inductance ◽  
Switching Performance ◽  
Power Modules ◽  
Primary Means

Abstract The need for high power density electrical converters/inverters dominates the power electronics realm, and wide bandgap semiconducting materials, such as gallium nitride (GaN), provide the enhanced material properties necessary to drive at higher switching speeds than traditional silicon. However, lateral GaN devices introduce packaging difficulties, especially when attempting a double-sided cooled solution. Herein, we describe optimization efforts for a 650V/30A, GaN half-bridge power module with an integrated gate driver and double-sided cooling capability. Two direct bonded copper (DBC) substrates provided the primary means of heat removal from the module. In addition to the novel topology, the team performed electrical/thermal co-design to increase the multi-functionality of module. Since a central PCB comprised the main power loop, the size and geometry of the vias and copper traces was analyzed to determine optimal functionality in terms of parasitic inductance and thermal spreading. Thermally, thicker copper layers and additional vias introduced into the PCB also helped reduce hot spots within the module. Upon fabrication of the module, it underwent electrical characterization to determine switching performance, as well as thermal characterization to experimentally measure the total module’s thermal resistance. The team successfully operated the module at 400 V, 30 A with a power loop parasitic inductance of 0.89 nH; experimental thermal measurements also indicated the module thermal resistance to be 0.43 C/W. The overall utility of the design improved commensurately by introducing simple, yet effective electrical/thermal co-design strategies, which can be applied to future power modules.

Simultaneous Determination of Steady Temperatures and Heat Fluxes on Surfaces of Three Dimensional Objects Using FEM

2001 ◽  
Author(s):  
Brian H. Dennis ◽  
George S. Dulikravich
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Heat Conduction ◽  
Three Dimensional ◽  
Heat Fluxes ◽  
Multiply Connected ◽  
Three Dimensional Objects ◽  
Solid Objects ◽  
System Solution

Abstract A finite element method (FEM) formulation is presented for the prediction of unknown steady boundary conditions in heat conduction on multiply connected three-dimensional solid objects. The present FEM formulation is capable of determining temperatures and heat fluxes on the boundaries where such quantities are unknown or inaccessible, provided such quantities are sufficiently over-specified on other boundaries. Details of the discretization, linear system solution techniques, regularization, and sample results for 3-D problems are presented.

scholarly journals A structure-exploiting numbering algorithm for finite elements on extruded meshes, and its performance evaluation in Firedrake

2016 ◽  
Vol 9 (10) ◽  
pp. 3803-3815 ◽  
Author(s):  
Gheorghe-Teodor Bercea ◽  
Andrew T. T. McRae ◽  
David A. Ham ◽  
Lawrence Mitchell ◽  
Florian Rathgeber ◽  
...  
Keyword(s):  
Finite Element ◽  
Performance Evaluation ◽  
Finite Elements ◽  
Aspect Ratio ◽  
Three Dimensional ◽  
Data Layout ◽  
Element System ◽  
Continuous Galerkin ◽  
Performance Penalty ◽  
The Cost

Abstract. We present a generic algorithm for numbering and then efficiently iterating over the data values attached to an extruded mesh. An extruded mesh is formed by replicating an existing mesh, assumed to be unstructured, to form layers of prismatic cells. Applications of extruded meshes include, but are not limited to, the representation of three-dimensional high aspect ratio domains employed by geophysical finite element simulations. These meshes are structured in the extruded direction. The algorithm presented here exploits this structure to avoid the performance penalty traditionally associated with unstructured meshes. We evaluate the implementation of this algorithm in the Firedrake finite element system on a range of low compute intensity operations which constitute worst cases for data layout performance exploration. The experiments show that having structure along the extruded direction enables the cost of the indirect data accesses to be amortized after 10–20 layers as long as the underlying mesh is well ordered. We characterize the resulting spatial and temporal reuse in a representative set of both continuous-Galerkin and discontinuous-Galerkin discretizations. On meshes with realistic numbers of layers the performance achieved is between 70 and 90 % of a theoretical hardware-specific limit.

Truss and Beam Finite Elements Revisited: A Derivation Based on Displacement-Field Decomposition

1996 ◽  
Vol 11 (4) ◽  
pp. 371-380 ◽  
Author(s):  
Alphose Zingoni
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Symmetry Group ◽  
Displacement Field ◽  
Three Dimensional ◽  
Beam Elements ◽  
Symmetry Properties ◽  
Mass Matrices ◽  
General Displacement

Where a finite element possesses symmetry properties, derivation of fundamental element matrices can be achieved more efficiently by decomposing the general displacement field into subspaces of the symmetry group describing the configuration of the element. In this paper, the procedure is illustrated by reference to the simple truss and beam elements, whose well-known consistent-mass matrices are obtained via the proposed method. However, the procedure is applicable to all one-, two- and three-dimensional finite elements, as long as the shape and node configuration of the element can be described by a specific symmetry group.

Microprocessor Silicon Die Temperature Prediction by Simplified Boundary Conditions

2015 ◽  
Author(s):  
Koji Nishi ◽  
Tomoyuki Hatakeyama ◽  
Shinji Nakagawa ◽  
Masaru Ishizuka
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Boundary Conditions ◽  
Thermal Resistance ◽  
Hot Spot ◽  
Three Dimensional ◽  
Thermal Design ◽  
Target Temperature ◽  
One Dimensional ◽  
Thermal Network

The thermal network method has a long history with thermal design of electronic equipment. In particular, a one-dimensional thermal network is useful to know the temperature and heat transfer rate along each heat transfer path. It also saves computation time and/or computation resources to obtain target temperature. However, unlike three-dimensional thermal simulation with fine pitch grids and a three-dimensional thermal network with sufficient numbers of nodes, a traditional one-dimensional thermal network cannot predict the temperature of a microprocessor silicon die hot spot with sufficient accuracy in a three-dimensional domain analysis. Therefore, this paper introduces a one-dimensional thermal network with average temperature nodes. Thermal resistance values need to be obtained to calculate target temperature in a thermal network. For this purpose, thermal resistance calculation methodology with simplified boundary conditions, which calculates thermal resistance values from an analytical solution, is also introduced in this paper. The effectiveness of the methodology is explored with a simple model of the microprocessor system. The calculated result by the methodology is compared to a three-dimensional heat conduction simulation result. It is found that the introduced technique matches the three-dimensional heat conduction simulation result well.

scholarly journals Polygonal finite elements for three-dimensional Voronoi-cell-based discretisations

2012 ◽  
Author(s):  
Kaliappan Jayabal ◽  
Andreas Menzel
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Three Dimensional ◽  
Specific Property ◽  
Voronoi Cell ◽  
Polycrystalline Materials ◽  
Element Formulation ◽  
Hybrid Finite Element ◽  
Grain Structures ◽  
Polygonal Elements

Hybrid finite element formulations in combination with Voronoi-cell-based discretisation methods can efficiently be used to model the behaviour of polycrystalline materials. Randomly generated three-dimensional Voronoi polygonal elements with varying numbers of surfaces and corners in general better approximate the geometry of polycrystalline microor rather grain-structures than the standard tetrahedral and hexahedral finite elements. In this work, the application of a polygonal finite element formulation to three-dimensional elastomechanical problems is elaborated with special emphasis on the numerical implementation of the method and the construction of the element stiffness matrix. A specific property of Voronoi-based discretisations in combination with a hybrid finite element approach is investigated. The applicability of the framework established is demonstrated by means of representative numerical examples.

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