Rapid multi-scale transient thermal modeling of packaged microprocessors using hybrid approach

2015 31st Thermal Measurement, Modeling &Amp; Management Symposium (SEMI-THERM)

Milojevic

et al. 2015

A thorough thermal analysis of integrated circuits (ICs) is essential to prevent temperature driven reliability issues, which might cause the failure of microelectronic devices. The classical analysis approach is based on finite element methods (FEM). However, in the last decades, other computational methodologies have been developed with the aim to obtain results more quickly and at a reasonable accuracy. In this paper, a transient fast thermal model (TFTM) methodology for 3D-ICs based on 3D-convolution and fast Fourier transform is presented. This methodology allows to quickly and accurately predict the temporal evolution of the chip temperature distribution, due to power dissipation that can be non-uniform both in time and space, in all tiers of the 3D package.In the first part of the paper the computational methodology is derived and described. Next, results are presented and validated with respect to conventional FEM simulations, showing good accuracy and computational time reduction. A realistic case, wherein different load switching scenarios are compared for a commercial floor-plan, is analyzed as an example of the applicability of the presented methodology. The speed of this algorithm, based on 3D-convolution, is compared with the one of previous work based on 2D-convolution and subseq uent time superposition.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

3D-convolution based fast transient thermal model for 3D integrated circuits: methodology and applications

2015 31st Thermal Measurement, Modeling &Amp; Management Symposium (SEMI-THERM)

Milojevic

et al. 2015

“…However, this is possible just for drastically simplified situations [9]. The third group of solutions relies on the mathematical theory of model order reduction in which the system of equations, obtained by FEM, is projected into lower dimensional spaces, using various projecting techniques, before being solved [10][11][12][13]. This class of methods relies on a full FEM simulation for each specific structure and design, requiring, therefore, modeling expertise by the end user and computationally expensive preprocessing operations.…”

Section: Introductionmentioning

confidence: 99%

Convolution based compact thermal model application to the evaluation of the thermal impact of die to die interface including interconnections

Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)

Beyne

et al. 2014

Thermal aware design of integrated circuits is essential to avoid reliability issues and failures especially in 3D-technology where active dies are placed on top of each other and more heat is dissipated on the same area available for cooling compared to conventional 2D-packages. A certain number of parameters can be selected to reduce temperature and temperature gradient. This paper is mainly focusing on the thermal impact of the dieto-die interface layer. This consists of adhesive material and arrays of interconnection structures. Besides being used for electrical die-die connections, they can be added to locally improve the low thermal conductivity of the adhesive. Short computational time is preferred for the thermal analysis of different designs: this is why various compact thermal models (CTMs) strategies have been developed. The one presented here, for the steady state temperature evaluation of two dies stacks, is based on convolution and fast Fourier transform. A novel correction methodology is introduced to deal with the material non-homogeneity in the interface layer. Case analyses, as the interface material thermal impact or the maximum achieved temperature as a function of the amount of interconnections, are presented in the paper and can be quickly and easily performed with this CTM.

“…The second group consists in the search of analytical solutions for the heat transfer equation in case of really simple geometric structures [9]. A third kind of approach relies on the mathematical techniques of model order reduction that consist in projecting the FE models over lower dimensional spaces exploiting various subspace projection methods [10][11][12][13]. The last group is based on the Green's function theory of solving partial differential equations [14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Convolution based compact thermal model for 3D-ICs: Methodology and accuracy analysis

19th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)

Beyne

et al. 2013

Thermal analysis is essential in 3D-IC technology due to the reduced footprint and higher power densities compared to conventional 2D packaging [1]. Compact thermal models (CTM) are being developed for fast evaluation of the thermal distribution in the 3D packages. The CTM discussed in this paper is based on the Green's function theory and exploits convolution and fast Fourier transform to compute the temperature profiles starting from matrices storing the power dissipation densities (power maps) and the temperature responses to hot spots. Detailed accuracy assessments are presented for the grid size and for the number of images to be considered for an accurate modelling of the lateral insulating boundary conditions. A two dies stack case study is also analysed showing good agreement with the finite element model results (error less than 0.5%). Finally, the algorithm computational time is discussed indicating a behaviour where N is the number of elements in the matrices.