Bridging the gap: package level and system level thermal modeling

Lakhkar

2010 12th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems

et al. 2010

The Wireless Telecom Industry is moving into a new age wherein remote data transmission capabilities must meet the demands of versatile mobile devices. These needs will be met by powerful new innovations such as 4G and WiMax.The radio control devices that are responsible for delivering the newest technologies to end-users are subject to stricter requirements of power than predecessors in compact space. These scenarios compel an increase in power density. Radio control units need to be relatively of the same size but deliver far more power. In addition to these internal heat sources, external solar loading comes as a natural consequence of standard outdoor telecom installations.Direct sunlight induces a heat flux onto as many as three sides of an outdoor device. The thermal management of the resulting system requires a simple yet effective solution against solar loading the device while allowing for adequate air flow.In this paper, we examined the benefits of a solar shroud placed over a high-powered radio control unit combined with 12 different vent configurations installed on the surface of the shroud using Computational Fluid Dynamics (CFD). Natural convection cooling methods don't require fans or pumps and hence are low maintenance and bear a low initial cost. The simulations were conducted under natural convection conditions. Both the flow and thermal phenomena was examined in the quest for optimal design. One of the benefits of having performed this analysis in a CFD environment was being able to examine the relationship between the mass flow of air through the primary heat sink and the corresponding drops in temperature levels at the internal heat sources. In this study, we were able to reduce the board temperature by 10%. The results suggested that external slat designs provided the lowest resistance to natural convection air flow and delivered the largest reduction in board temperature.

Section: Literature Reviewmentioning

confidence: 99%

Solar shroud design using Computational Fluid Dynamics

Lakhkar

2010 12th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems

et al. 2010

“…Restricted topology versions of the CTM have been developed including a two-node model (Wang et al 2000), containing only a junction node and one node representing the ambient temperature. A second approach restricts the topology to an edge set consisting entirely of edges connecting the junction node to each boundary node, but with no edges connecting boundary nodes (Adams et al 1997).…”

Section: R Ijmentioning

confidence: 99%

A parameter optimization heuristic for a temperature estimation model

et al. 2008

We present a heuristic technique for solving a parameter estimation problem that arises in modeling the thermal behavior of electronic chip packages. Compact Thermal Models (CTMs) are network models of steady state thermal behavior, which show promise in augmenting the use of more detailed and computationally expensive models. The CTM parameter optimization problem that we examine is a nonconvex optimization problem in which we seek a set of CTM parameters that best predicts, under general conditions, the thermal response of a particular chip package geometry that has been tested under a small number of conditions. We begin by developing a nonlinear programming formulation for this parameter optimization problem, and then develop an algorithm that uses special characteristics of the optimization problem to quickly generate heuristic solutions. Our algorithm descends along a series of solutions to one-dimensional nonconvex optimization problems, obtaining a locally optimal set of model parameters at modest computational cost. Finally, we provide some experimental results and recommendations for extending this research.

“…3 can be represented by an ordinary differential equation in Eq. (18), where [C] is the thermal capacitance matrix, [K] if the thermal conductance matrix, and {Q} is the heat source matrix.…”

Section: Adaptive Discretization Of Package Substrate and The Reductimentioning

confidence: 99%

“…These are the finite difference method (FDM), the finite volume method (FVM), the finite element method (FEM), and the boundary element method (BEM). These methods semi-discretize the heat transfer partial differential equation, and transform it into a system of ordinary differential equations (18). However, the application of Diritchlet, Neumann, and convection boundary conditions would change the ODEs as in Eq.…”

Section: Adaptive Discretization Of Package Substrate and The Reductimentioning

confidence: 99%

Investigation and a practical compact network model of thermal stress in integrated circuits

Krishnamoorthy

Chowdhury

2009

ICA

This paper first investigates the non-uniform spatial thermal distribution in sub-100nm integrated circuits. A practical network-based Compact Thermal Modeling (CTM) technique has been proposed to model this thermal stress. The proposed technique, which can be integrated with modern CAD tools, represents IC package as a network in which a set of boundary nodes serve as surrogates for physical regions of the chip. In this network a junction node represents the chip's power junction, and arcs permit thermal communication between adjacent nodes. Due to the complex nature of micro-and nano-systems, the discrete models (resulting from the finite element method (FEM) or other methods) are usually very large (of the order of 100,000). Even though modern computers are able to handle engineering problems of this size, the system-level simulation would become prohibitive if the detailed models were directly used. The proposed CTM is condensed using Static Matrix Condensation methodology where the system matrices obtained by the spatial discretization of heat transfer partial differential equation (PDE) are reduced by the elimination of heat sources, surface nodes and internal nodes, however maintaining the thermal communication among the nodes. The formal conversion of governing PDE systems to low-dimensional ordinary differential equation (ODE) systems is to reduce the complexity, and at the same time preserve the accuracy of the model. The reduced system can be used to either synthesize a resistive network or formulate a set of connection equations to be connected to higher simulation levels.