Active control of boundary conditions for dynamic thermal characterization of electronic components

The need to accurately predict component junction temperatures on fully operational printed circuit boards can lead to complex and time consuming simulations if component details are to be adequately resolved. An analytical approach for characterizing electronic packages is presented, based on the steady-state solution of the Laplace equation for general rectangular geometries, where boundary conditions are uniformly specified over specific regions of the package. The basis of the solution is a general three-dimensional Fourier series solution which satisfies the conduction equation within each layer of the package. The application of boundary conditions at the fluid-solid, package-board and layer-layer interfaces provides a means for obtaining a unique analytical solution for complex IC packages. Comparisons are made with published experimental data for both a plastic quad flat package and a multichip module to demonstrate that an analytical approach can offer an accurate and efficient solution procedure for the thermal characterization of electronic packages. [S1043-7398(00)01403-1]

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Thermal characterization of building walls under random boundary conditions

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4049432 ◽

2020 ◽

pp. 1-12

Author(s):

Emilio Sassine ◽

Yassine Cherif ◽

Emmanuel Antczak ◽

Joseph Dgheim

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Boundary Conditions ◽

Transfer Matrix ◽

Numerical Models ◽

Thermal Characterization ◽

Thermal Capacity ◽

Data Logging ◽

Random Boundary

Abstract This work aims to improve the knowledge on dynamic thermophysical characterization of building envelopes by comparing three numerical methods applied on an experimental wall made of masonry brick. The thermal conductivity λ and the thermal capacity ρcp are determined by performing a data fitting optimization between the experimental measurements of the heat flux and the heat flux resulting from these numerical models. The experimental device consists of a thermal box with a controlled ambiance through a radiator linked to a thermostatic bath and placed inside the thermal box, on the opposite side facing the wall. Three different methods were examined: The Heat Transfer Matrix analytical method (HTM) using the heat transfer matrix, the Finite Element Method (FEM) using COMSOL Multiphysics® software, and the Building Simulation Model method (BSM) using TRNSYS® Type 56 coupled with Genopt® optimization tool. The reproducibility of the methods was also validated through two other datasets (one random and one harmonic). The obtained results were satisfactory for both λ and for ρcp and for the three studied methods with deviations less than 5% between the results of the different methods. The data logging duration for random boundary conditions was found to be around five days while in harmonic boundary conditions two days were sufficient for the solution to converge.

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Thermal Characterization of Electronic Components Using Single-detector IR Measurement and 3D Heat Transfer Modelling

2020 27th International Conference on Mixed Design of Integrated Circuits and System (MIXDES) ◽

10.23919/mixdes49814.2020.9155993 ◽

2020 ◽

Author(s):

Michal Kopec ◽

Boguslaw Wiecek

Keyword(s):

Heat Transfer ◽

Thermal Characterization ◽

Electronic Components ◽

Single Detector ◽

Transfer Modelling

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Nonlinear Electro-Thermal Monte Carlo Device Simulation

Journal of Heat Transfer ◽

10.1115/1.4045305 ◽

2019 ◽

Vol 142 (2) ◽

Author(s):

Ky Merrill ◽

Marco Saraniti

Keyword(s):

Monte Carlo ◽

Boundary Conditions ◽

Thermal Characterization ◽

High Electron Mobility Transistor ◽

Energy Balance Equation ◽

High Electron ◽

Convective Boundary ◽

Element Analysis ◽

Kirchhoff Transformation

Abstract A model of self-heating is incorporated into a cellular Monte Carlo (CMC) particle device simulator. This is done through the solution of an energy balance equation (EBE) for phonons, which self-consistently couples charge and heat transport in the simulation. First, several tests are performed to verify the applicability and accuracy of the proposed nonlinear iterative solver in the presence of convective boundary conditions, as compared to a finite element analysis (FEA) solver as well as using the Kirchhoff Transformation. Finally, a fully coupled electro-thermal characterization of a GaN/AlGaN high electron mobility transistor (HEMT) is performed, and the effects of nonideal interfaces and boundary conditions are studied.

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