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...]
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...]
Fan selection – quick techniques to compare various tube-axial fan designs
The worldwide market for tube-axial fans is very large and, as a consequence, the number of tube-axial suppliers is significant. This article will focus on the techniques that can be used to quickly compare various tube-axial fan product offerings, in order to provide a quick screen and minimize the number of suppliers that are submitted to a detailed evaluation. Supplier … [Read more...]
Forced convection cooling of airborne electronics
Figure 1. AFT description Fin pitch = 25.01 per in = 985 per mPlate spacing, b = 0.200 in = 5.08 x 10-3 m Fin Length = 0.111 in = 2.8 x 10-3 m Flow passage hydraulic diameter 4rh = 0.004905 ft = 1.50 x 10-3 m Fin metal thickness = 0.004 in = 0.102 x 10-3 m Total heat transfer area/volume between plates, ß = 719.4 ft2 / ft3 = 2,360 m2 / m3 Fin area / total area = … [Read more...]
How to evaluate fan life
Convection air cooling is still the most commonly used method of coolingmicroelectronics. In order to deliver air cooled computer equipment with higherreliability, we need to focus on the life expectancy of the air moving devices(AMDs). However, this is not a trivial exercise because there are so manyvariables and there is no industry standard for AMD life test procedures. … [Read more...]
