Space/avionic industries industries include satellites, space stations, airplanes, and missiles, where understanding thermal radiation is a critical part of design. The figure shows a typical board used in a satellite application. The board relies upon thermal screws and wedge locks at the upper and lower edges to conduct the heat to the sink.
High reliability is a demand in these industry segments where large numbers of complex boards are encountered. The figure shows a board in a cardcage at natural convection cooling. Heat sinks have been used to cool some components. ECAD interfaces give a perfect translation of component placement, and library information to speed the setup process for these densely packed boards.
These boards frequently have a few components, such as CPUs, with high power dissipation. The boards are usually very large with many components. Chip fans, heat sinks, or local impingement jets are used along with strong forced convection as cooling methods. The figure shows the analysis of a large mother board. Again, the ECAD interface is essential for these boards because of the vast number of components.
In many automotive applications, high currents pass through heavy traces on the board and generate significant heat. A Trace Version of HyperLynx Thermal is available for these types of special boards. The hot traces are modeled on the board using a power density factor. Some typical results for an automotive trace application are shown in the figure.
Power supplies typically have many tall components generating significant amounts of power. These components can create air flow blockage effects which can severely impact design. A horizontal power supply operating at natural convection is simulated in the figure. Although the transformer has high power, its temperature is low due to the large surface area. The hot components are the ones of medium power and size.