Introduction Recent advances in mobile communications have enabled large scale development of handheld telecommunication products. Such products include cellular phones, pagers, two-way radios, personal digital assistants (PDAs), and other wireless and wireline equipment. The technological enhancements at device, package, and system levels have resulted in increased … [Read more...]
Conduction heat transfer in a printed circuit board
In this issue, we examine heat flow in a printed circuit board (PCB), which typically is a layered composite consisting of copper foil and a glass-reinforced polymer (FR-4). A cross-sectional view of such a laminated structure is illustrated in Figure 1. The Figure indicates the numbering system that will be used for indicating the different layers, numbered 1 through to … [Read more...]
Calculating Spreading Resistance in Heat Sinks
Accident? Consider the scenario where a designer wishes to incorporate a newly developed device into a system and soon learns that a heat sink is needed to cool the device. The designer finds a rather large heat sink in a catalog which marginally satisfies the required thermal criteria. Due to other considerations, such as fan noise and cost constraints, an attempt to use a … [Read more...]
Convection and radiation
In last issue's calculation corner,a simple 1-dimensional conduction calculation was described. This time, we look at the other two basic heat transfer processes, namely convection and radiation. In actual applications with multiple heat sources with complicated geometries, the effect of each of these mechanisms on the heat transfer process can be quite difficult to calculate. … [Read more...]
Experimental evaluation of the local convective heat transfer from configurations of wall-mounted cubes in a channel flow
Figure 1: Sketches of the measurement cube. Introduction Computational fluid dynamics (CFD) codes are frequently used as design tools to predict the thermal processes in electronic circuitry. CFD codes can easily cope with a high level of complexity (component, board and system levels) which makes them attractive to use. However, the thermal and kinematic complexity of the … [Read more...]
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