In last issue's column, a method for calculating the thermal conductivity of a printed circuit board (PCB) was described. Now, we look at a more complicated heat transfer process, namely the loss of heat from the surface of a PCB to the ambient air. This situation is more challenging to describe mathematically since it involves the simultaneous processes of heat spreading by … [Read more...]
Pressure drop coefficients for thin perforated plates
Almost everyone working on pressure drop coefficients of perforated plates encounters the work of I.E. Idelchick {1}. A plethora of graphs or equations - some of which are impossible to evaluate quickly - must then be addressed. To simplify this issue for the reader, this month's Technical Data page has been designed to provide an overview of this information. When focusing on … [Read more...]
Interaction of the system and module-level thermal phenomena- a flip-chip/BGA example
Fig. 1: Levels in a computer environment. Introduction Increasing demands for higher performance in microprocessors have a direct effect on chip power and heat generation. Increased function and miniaturization of the packages result in thermal challenges that require a thorough understanding of the system's thermal performance under all possible field conditions. Regardless … [Read more...]
Forced convection cooling inside an electronics enclosure
Introduction One of the more complex thermal problems in electronics is the modeling of complete systems, such as an enclosure containing electronic components. A typical example would be a power supply, including heat sinks and a cooling fan. This problem becomes more difficult when there are multiple heat sinks and other large components arranged in an arbitrary manner inside … [Read more...]
Thermal management of handheld telecommunication products
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...]
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