Introduction Increased performance in electronic systems along with higher packaging densities have made temperature a critical parameter. Measurements of temperature, velocity and heat transfer in electronic systems are challenging due to complex materials, configurations, and non-isothermal flows. Earlier articles have considered different aspects of thermal measurements. … [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...]
Measuring fluid velocity in electronic enclosures
Thermal analysis and characterization of electronic systems requires a knowledge of fluid velocity. In pursuit of this information, we often resort to measurement or calculation. The issue of measurement becomes a challenge since we are dealing with rather complex flows that tend to be highly nonisothermal. Therefore, it is our intention in this article to highlight the need … [Read more...]
Evaluation of different heat transfer coefficient definitions
The analysis of convective heat transfer problems pivots on the accurate knowledge of the heat transfer coefficient, h. The heat transfer coefficient is affected by many parameters which have been defined differently by various investigators. for natural convection cases, the temperature distribution is the governing parameter, while for forced convection problems, the fluid … [Read more...]
