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...]
Recent Japanese thermal solutions for portable computers
Introduction Mobile computing is poised to shape the way we live our lives, allowing people to generate, retrieve, and process data anywhere and at any time. The infrastructure for mobile computing is rapidly developing, as evidenced by the recent growth of cellular phone networks and a constant stream of innovations in portable electronic equipment. Mobile computing is also … [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...]
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 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...]