Page 382 - Mechanical Engineers' Handbook (Volume 4)

Mechanical Engineers’ Handbook: Energy and Power, Volume 4, Third Edition.

Edited by Myer Kutz

Copyright  2006 by John Wiley & Sons, Inc.

CHAPTER 11
COOLING ELECTRONIC EQUIPMENT
Allan Kraus
Beachwood, Ohio
Avram Bar-Cohen
Department of Mechanical Engineering
University of Maryland
College Park, Maryland
Abhay A. Wative
Intel Corp
Chandler, Arizona

1 THERMAL MODELING 371 2.2 Natural Convection Heat Sinks 388
1.1 Introduction 371 2.3 Thermal Interface Resistance 392
1.2 Conduction Heat Transfer 371 2.4 Forced Convection 395
1.3 Convective Heat Transfer 375
1.4 Radiative Heat Transfer 378 3 THERMAL CONTROL
1.5 Chip Module Thermal TECHNIQUES 401
Resistances 378 3.1 Extended Surface and
Heat Sinks 401
2 HEAT-TRANSFER 3.2 The Cold Plate 406
CORRELATIONS 3.3 Thermoelectric Coolers 409
FOR ELECTRONIC 3.4 Spray Cooling 413
EQUIPMENT COOLING 385
2.1 Natural Convection in REFERENCES 417
Confined Spaces 385

1 THERMAL MODELING
1.1 Introduction

To determine the temperature differences encountered in the flow of heat within electronic
systems, it is necessary to recognize the relevant heat transfer mechanisms and their gov-
erning relations. In a typical system, heat removal from the active regions of the microcir-
cuit(s) or chip(s) may require the use of several mechanisms, some operating in series and
others in parallel, to transport the generated heat to the coolant or ultimate heat sink. Prac-
titioners of the thermal arts and sciences generally deal with four basic thermal transport
modes: conduction, convection, phase change, and radiation.

1.2 Conduction Heat Transfer

One-Dimensional Conduction
Steady thermal transport through solids is governed by the Fourier equation, which, in one-
dimensional form, is expressible as

371