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...]
Cooling Electronics at High Altitudes Made Easy
Introduction High altitude air cooling has always been somewhat of a mystery to the uninformed. The first reaction to the situation is that there is just not enough air at altitudes greater than six kilometers (20,000 ft). At times this may be true, but many things can be done to improve the cooling and obtain an acceptable design. The most important thing to remember when … [Read more...]
Disk drive reliability and thermal management
Disk drive reliability and thermal management Hard disk drives are electromechanical systems which store information. They are the most complex electronic sub-assembly within a computer. If a microprocessor can qualify as the "heart" of a computer system, a disk drive can qualify as the "brain". Drives store and retrieve data in milliseconds, measured as access and transfer … [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...]
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...]
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