Thermal-Designing Your Way to a Cooler High-Performance Tablet (.PDF Download)

Managing heat is not only a multi-disciplinary challenge, it’s also multi-level. An IC package that’s thermally optimized doesn’t mean the entire system is good. Effective heat management at the printed-circuit-board (PCB) level doesn’t guarantee high reliability. Design and thermal analysis must be done at multiple levels, including the ICs and PCBs in the product enclosure. Computational-fluid-dynamics (CFD) software connects these levels and crosses disciplines so that convection, conduction, and radiation heat transfer of the entire system can be considered throughout the design to manufacturing processes.

Optimizing the cooling system for an electronic product involves juggling multiple design variables such as airflow rate, fan, and vent locations, as well as heat-sink size and the physical location of boards. Successful design engineers use a comprehensive approach to thermal management, whether they’re a single engineer in a small company tasked with the entire design and optimization process, or several teams of engineers spread around the globe who provide components that fit into a single product.

Mechanical engineers using mechanical-design-automation software are responsible for all aspects of the product’s physical design except the ICs and PCBs, so they need to collaborate with electronic designers using electronic-design-automation software. These two domains used to be linked only via en masse data transfer (through neutral file formats such as IDF), usually without filtering for thermally relevant information.

Good thermal design needs accurate electronic design information, such as individual trace geometries to capture their cooling effect and the interaction between components. This resulted in excessive design detail that required the designer to manually simplify the model for CFD simulations or suffer excessive CFD run times and risky convergence.