Multi-Scale Transient Thermal Analysis of Microelectronics

2012 ◽  
Author(s):  
Banafsheh Barabadi ◽  
Satish Kumar ◽  
Valeriy Sukharev ◽  
Yogendra K. Joshi
Keyword(s):  
Flip Chip ◽  
Computational Cost ◽  
Close Correlation ◽  
Device Fabrication ◽  
Fe Model ◽  
Computationally Efficient ◽  
Suggested Approach ◽  
Multi Scale ◽  
Microelectronic Devices ◽  
Transient Thermal

Thermal transport in microelectronic devices spans length scales from tens of nanometers to hundreds of millimeters. One of the major challenges in maintaining quality and reliability in today’s microelectronic devices comes from the ever increasing level of integration in the device fabrication as well as the high level of current densities that are carried through the microchip during operation. Consequently, significant opportunities for energy efficiency exist at various levels of the length scale hierarchy by optimization of thermal management resources. In this study, we developed a computationally efficient and accurate multi-scale reduced order transient thermal methodology consisting of hybrid implementation of two different multi-scale approaches: 1. “Progressive Zoom-in” method and 2. “Proper Orthogonal Decomposition (POD)” technique. The suggested approach provides the ability to predict different thermal scenarios based on one representative thermal scenario, while maintaining the desired spatial and temporal accuracy. In this paper, a Flip Chip Ball Grid Array (FCBGA) package was considered for hybrid modeling. To demonstrate the capability of POD method in predicting different thermal scenarios, the chip is divided into ten function blocks. Each of these blocks had a different randomly generated dynamic power source. To validate this methodology, the results were compared with a finite element (FE) model developed in COMSOL®. The behavior of the POD model was in good agreements with the corresponding FE model. This close correlation provides the capability of predicting other thermal scenarios based on a smaller sample set which can significantly decrease the computational cost.

Multiscale Transient Thermal Analysis of Microelectronics

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Banafsheh Barabadi ◽  
Satish Kumar ◽  
Valeriy Sukharev ◽  
Yogendra K. Joshi
Keyword(s):  
Temperature Rise ◽  
Flip Chip ◽  
Computational Cost ◽  
Computational Effort ◽  
Heat Fluxes ◽  
Transient Temperature ◽  
Multiscale Approach ◽  
Fe Model ◽  
Power Sources ◽  
Transient Thermal

In a microelectronic device, thermal transport needs to be simulated on scales ranging from tens of nanometers to hundreds of millimeters. High accuracy multiscale models are required to develop engineering tools for predicting temperature distributions with sufficient accuracy in such devices. A computationally efficient and accurate multiscale reduced order transient thermal modeling methodology was developed using a combination of two different approaches: “progressive zoom-in” method and “proper orthogonal decomposition (POD)” technique. The capability of this approach in handling several decades of length scales from “package” to “chip components” at a considerably lower computational cost, while maintaining satisfactory accuracy was demonstrated. A flip chip ball grid array (FCBGA) package was considered for demonstration. The transient temperature and heat fluxes calculated on the top and bottom walls of the embedded chip at the package level simulations are employed as dynamic boundary conditions for the chip level simulation. The chip is divided into ten function blocks. Randomly generated dynamic power sources are applied in each of these blocks. The temperature rise in the different layers of the chip calculated from the multiscale model is compared with a finite element (FE) model. The close agreement between two models confirms that the multiscale approach can predict temperature rise accurately for scenarios corresponding to different power sources in functional blocks, without performing detailed FE simulations, which significantly reduces computational effort.

Transient Thermal Characterization of a Stacked Multichip Package

2007 ◽  
Vol 4 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Kimmo Kaija ◽  
Pekka Heino
Keyword(s):  
Steady State ◽  
Flip Chip ◽  
Thermal Characterization ◽  
Transient Behavior ◽  
Fe Model ◽  
Thermal Test ◽  
Transient Thermal ◽  
Temperature Responses

This paper is a case study of the thermal behavior of a stacked multichip package (SMCP). The aim is to measure temperature responses when heat is dissipated on different dice and to characterize the behavior with a compact thermal model (CTM) that accurately models steady-state and transient responses with a simple thermal RC -network. The measured package consists of three stacked layers, where each layer has one thinned flip chip attached die on an aramid interposer. The package's thermal responses were measured with thermal test dice that contain heaters and temperature sensors. The package was modeled with a finite element method (FEM) and the simulated temperature responses showed reasonable agreement with measured data. The FE model was further used to provide reference thermal data under different boundary conditions for CTM synthesis. The obtained CTM models accurately the steady-state and transient behavior and can be used as simplified model of the measured SMCP for further thermal analysis.

Computationally efficient permanent magnet traction motor loss assessment

2018 ◽  
Vol 37 (6) ◽  
pp. 2093-2108 ◽  
Author(s):  
Athanasios Sarigiannidis ◽  
Minos Beniakar ◽  
Antonios Kladas
Keyword(s):  
Permanent Magnet ◽  
Computational Cost ◽  
Operating Conditions ◽  
Total Power ◽  
Fe Model ◽  
Evaluation Technique ◽  
Computationally Efficient ◽  
Operating Cycle ◽  
Traction Motor ◽  
Content Type

Purpose This paper aims to introduce a computationally efficient hybrid analytical–finite element (FE) methodology for loss evaluation in electric vehicle (EV) permanent magnet (PM) traction motor applications. In this class of problems, eddy current losses in PMs and iron laminations constitute an important part of overall drive losses, representing a key design target. Design/methodology/approach Both surface mounted permanent magnet (SMPM) and double-layer interior permanent magnet (IPM) motor topologies are considered. The PM eddy losses are calculated by using analytical solutions and Fourier harmonic decomposition. The boundary conditions are based on slot opening magnetic field strength tangential component in the air gap in the SMPM topology case, whereas the numerically evaluated normal flux density variation on the surface of the outer PM is implemented in the IPM case. Combined analytical–loss evaluation technique has been verified by comparing its results to a transient magnetodynamic two-dimensional FE model ones. Findings The proposed loss evaluation technique calculated the total power losses for various operating conditions with low computational cost, illustrating the relative advantages and drawbacks of each motor topology along a typical EV operating cycle. The accuracy of the method was comparable to transient FE loss evaluation models, particularly around nominal speed. Originality/value The originality of this paper is based on the development of a fast and accurate PM eddy loss model for both SMPM and IPM motor topologies for traction applications, combining effectively both analytical and FE techniques.

Prediction of Transient Thermal Behavior of Planar Interconnect Architecture Using Proper Orthogonal Decomposition Method

2011 ◽  
Author(s):  
Banafsheh Barabadi ◽  
Yogendra K. Joshi ◽  
Satish Kumar
Keyword(s):  
Thermal Behavior ◽  
Proper Orthogonal Decomposition ◽  
Joule Heating ◽  
Computational Cost ◽  
Orthogonal Decomposition ◽  
Galerkin Projection ◽  
Fe Model ◽  
Inhomogeneous System ◽  
Transient Thermal ◽  
Proper Orthogonal

A major challenge in maintaining quality and reliability in today’s microelectronics devices comes from the ever increasing level of integration in the device fabrication as well as the high level of current densities that are carried through the microchip during operation. Cyclic thermal events during operation, stemming from Joule heating of the metal lines, can lead to fatigue failure due to the varying thermal expansion coefficients of the different materials that compose the microchip package. To aid in the avoidance of such device failures, it is imperative to develop a predictive capability for the thermal response of micro-electronic circuits. This work studied the problem of transient Joule heating in interconnects in a two-dimensional (2D) inhomogeneous system using a reduced order modeling approach of the Proper Orthogonal Decomposition (POD) method and Galerkin Projection Technique. This study considers an interconnect structure embedded in the bulk of a microelectronic device. The effect of different types of current pulses, pulse duration, and pulse amplitude were investigated. By using a representative step function as the heat source, the model predicted the exact transient thermal behavior of the system for all other cases without generating any new observations, using just a few POD modes. To validate this unique capability, the result of the POD model was compared with a finite element (FE) model developed in LS-DYNA®. The behaviors of the POD models were in good agreements with the corresponding FE models. This close correlation provides the capability of predicting other cases based on a smaller sample set which can significantly decrease the computational cost.

Thermal Characterization of Planar Interconnect Architectures Under Transient Currents

2009 ◽  
Author(s):  
Banafsheh Barabadi ◽  
Yogendra K. Joshi ◽  
Satish Kumar ◽  
Gamal Refai-Ahmed
Keyword(s):  
Joule Heating ◽  
Thermal Characterization ◽  
Fe Model ◽  
Time Step ◽  
Multi Scale ◽  
Tlm Method ◽  
Interconnect Architectures ◽  
Variable Time Step ◽  
Transient Thermal ◽  
Short Time

The quality and reliability of interconnects in microelectronics is a major challenge considering the increasing level of integration and high current densities. This work studied the problem of transient Joule heating in interconnects in a two-dimensional (2D) inhomogeneous model. The transmission line matrix (TLM) method was implemented with link-resistor (LR) and link-line (LL) formulations, and the results were compared with a finite element (FE) model that was developed in LSDyna. This comparison showed that the overall behavior of the TLM models were in good agreement with the FE model while, near the heat source, the transient TLM solutions developed slower than the FE solution. The steady-state results of the two models were identical. The two TLM formulations yielded slightly different transient results, with the LL result growing slower particularly at the source boundary and becoming unstable at short time-steps. It was concluded that the LR formulation is more accurate for transient thermal analysis. Computational efficiency of the TLM method and its ability to accept non-uniform 2D and 3D mesh and variable time-step makes it a good candidate for multi-scale analysis of Joule heating in the interconnects.

scholarly journals Compressed pseudo-SLAM: pseudorange-integrated compressed simultaneous localisation and mapping for unmanned aerial vehicle navigation

2021 ◽  
pp. 1-13
Author(s):  
Jonghyuk Kim ◽  
Jose Guivant ◽  
Martin L. Sollie ◽  
Torleiv H. Bryne ◽  
Tor Arne Johansen
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Computational Cost ◽  
Satellite System ◽  
Measurement Unit ◽  
Electronic Systems ◽  
Computationally Efficient ◽  
Global Correlation ◽  
Aerial Vehicle ◽  
Correlation Information ◽  
Global Navigation Satellite

Abstract This paper addresses the fusion of the pseudorange/pseudorange rate observations from the global navigation satellite system and the inertial–visual simultaneous localisation and mapping (SLAM) to achieve reliable navigation of unmanned aerial vehicles. This work extends the previous work on a simulation-based study [Kim et al. (2017). Compressed fusion of GNSS and inertial navigation with simultaneous localisation and mapping. IEEE Aerospace and Electronic Systems Magazine, 32(8), 22–36] to a real-flight dataset collected from a fixed-wing unmanned aerial vehicle platform. The dataset consists of measurements from visual landmarks, an inertial measurement unit, and pseudorange and pseudorange rates. We propose a novel all-source navigation filter, termed a compressed pseudo-SLAM, which can seamlessly integrate all available information in a computationally efficient way. In this framework, a local map is dynamically defined around the vehicle, updating the vehicle and local landmark states within the region. A global map includes the rest of the landmarks and is updated at a much lower rate by accumulating (or compressing) the local-to-global correlation information within the filter. It will show that the horizontal navigation error is effectively constrained with one satellite vehicle and one landmark observation. The computational cost will be analysed, demonstrating the efficiency of the method.

scholarly journals Data-Informed Decomposition for Localized Uncertainty Quantification of Dynamical Systems

Vibration ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 49-63
Author(s):  
Waad Subber ◽  
Sayan Ghosh ◽  
Piyush Pandita ◽  
Yiming Zhang ◽  
Liping Wang
Keyword(s):  
Dynamical Systems ◽  
Computational Cost ◽  
Three Dimensional ◽  
Region Of Interest ◽  
System Response ◽  
Computational Domain ◽  
User Interest ◽  
Numerical Resolution ◽  
Multi Scale ◽  
Operation Conditions

Industrial dynamical systems often exhibit multi-scale responses due to material heterogeneity and complex operation conditions. The smallest length-scale of the systems dynamics controls the numerical resolution required to resolve the embedded physics. In practice however, high numerical resolution is only required in a confined region of the domain where fast dynamics or localized material variability is exhibited, whereas a coarser discretization can be sufficient in the rest majority of the domain. Partitioning the complex dynamical system into smaller easier-to-solve problems based on the localized dynamics and material variability can reduce the overall computational cost. The region of interest can be specified based on the localized features of the solution, user interest, and correlation length of the material properties. For problems where a region of interest is not evident, Bayesian inference can provide a feasible solution. In this work, we employ a Bayesian framework to update the prior knowledge of the localized region of interest using measurements of the system response. Once, the region of interest is identified, the localized uncertainty is propagate forward through the computational domain. We demonstrate our framework using numerical experiments on a three-dimensional elastodynamic problem.

A two-stage design optimization framework for multifield origami-inspired structures

2021 ◽  
pp. 1045389X2110116
Author(s):  
Wei Zhang ◽  
Saad Ahmed ◽  
Jonathan Hong ◽  
Zoubeida Ounaies ◽  
Mary Frecker
Keyword(s):  
Case Studies ◽  
Computing Time ◽  
Computational Cost ◽  
High Fidelity ◽  
Fe Model ◽  
Two Stage ◽  
Baseline Design ◽  
Optimization Framework ◽  
Highly Nonlinear ◽  
Stage 1

Different types of active materials have been used to actuate origami-inspired self-folding structures. To model the highly nonlinear deformation and material responses, as well as the coupled field equations and boundary conditions of such structures, high-fidelity models such as finite element (FE) models are needed but usually computationally expensive, which makes optimization intractable. In this paper, a computationally efficient two-stage optimization framework is developed as a systematic method for the multi-objective designs of such multifield self-folding structures where the deformations are concentrated in crease-like areas, active and passive materials are assumed to behave linearly, and low- and high-fidelity models of the structures can be developed. In Stage 1, low-fidelity models are used to determine the topology of the structure. At the end of Stage 1, a distance measure [Formula: see text] is applied as the metric to determine the best design, which then serves as the baseline design in Stage 2. In Stage 2, designs are further optimized from the baseline design with greatly reduced computing time compared to a full FEA-based topology optimization. The design framework is first described in a general formulation. To demonstrate its efficacy, this framework is implemented in two case studies, namely, a three-finger soft gripper actuated using a PVDF-based terpolymer, and a 3D multifield example actuated using both the terpolymer and a magneto-active elastomer, where the key steps are elaborated in detail, including the variable filter, metrics to select the best design, determination of design domains, and material conversion methods from low- to high-fidelity models. In this paper, analytical models and rigid body dynamic models are developed as the low-fidelity models for the terpolymer- and MAE-based actuations, respectively, and the FE model of the MAE-based actuation is generalized from previous work. Additional generalizable techniques to further reduce the computational cost are elaborated. As a result, designs with better overall performance than the baseline design were achieved at the end of Stage 2 with computing times of 15 days for the gripper and 9 days for the multifield example, which would rather be over 3 and 2 months for full FEA-based optimizations, respectively. Tradeoffs between the competing design objectives were achieved. In both case studies, the efficacy and computational efficiency of the two-stage optimization framework are successfully demonstrated.

scholarly journals Numerical Modeling and Safety Design for Lithium-Ion Vehicle Battery Modules Subject to Crush Loading

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 118
Author(s):  
Feng Zhu ◽  
Runzhou Zhou ◽  
David J. Sypeck
Keyword(s):  
Failure Modes ◽  
Computational Study ◽  
Short Circuit ◽  
Computational Cost ◽  
Lithium Ion ◽  
Simplified Model ◽  
Homogeneous Material ◽  
Fe Model ◽  
Safety Design ◽  
Battery Module

In this work, a computational study was carried out to simulate crushing tests on lithium-ion vehicle battery modules. The tests were performed on commercial battery modules subject to wedge cutting at low speeds. Based on loading and boundary conditions in the tests, finite element (FE) models were developed using explicit FEA code LS-DYNA. The model predictions demonstrated a good agreement in terms of structural failure modes and force–displacement responses at both cell and module levels. The model was extended to study additional loading conditions such as indentation by a cylinder and a rectangular block. The effect of other module components such as the cover and cooling plates was analyzed, and the results have the potential for improving battery module safety design. Based on the detailed FE model, to reduce its computational cost, a simplified model was developed by representing the battery module with a homogeneous material law. Then, all three scenarios were simulated, and the results show that this simplified model can reasonably predict the short circuit initiation of the battery module.

scholarly journals A parametric prediction of the Young’s modulus of polymers enhanced with ΜWCNTs

2018 ◽  
Vol 233 ◽  
pp. 00025
Author(s):  
P.V. Polydoropoulou ◽  
K.I. Tserpes ◽  
Sp.G. Pantelakis ◽  
Ch.V. Katsiropoulos
Keyword(s):  
Young’S Modulus ◽  
Elastic Properties ◽  
Young's Modulus ◽  
Experimental Results ◽  
Scale Model ◽  
Fe Model ◽  
Multi Scale ◽  
Unit Cells ◽  
Random Dispersion

In this work a multi-scale model simulating the effect of the dispersion, the waviness as well as the agglomerations of MWCNTs on the Young’s modulus of a polymer enhanced with 0.4% MWCNTs (v/v) has been developed. Representative Unit Cells (RUCs) have been employed for the determination of the homogenized elastic properties of the MWCNT/polymer. The elastic properties computed by the RUCs were assigned to the Finite Element (FE) model of a tension specimen which was used to predict the Young’s modulus of the enhanced material. Furthermore, a comparison with experimental results obtained by tensile testing according to ASTM 638 has been made. The results show a remarkable decrease of the Young’s modulus for the polymer enhanced with aligned MWCNTs due to the increase of the CNT agglomerations. On the other hand, slight differences on the Young’s modulus have been observed for the material enhanced with randomly-oriented MWCNTs by the increase of the MWCNTs agglomerations, which might be attributed to the low concentration of the MWCNTs into the polymer. Moreover, the increase of the MWCNTs waviness led to a significant decrease of the Young’s modulus of the polymer enhanced with aligned MWCNTs. The experimental results in terms of the Young’s modulus are predicted well by assuming a random dispersion of MWCNTs into the polymer.

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