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In simulation-driven thermal design, productivity is king. In the past, engineers have faced a difficult choice between design productivity and tool capability, especially when attempting to explore different cooling options and the design space associated with the chosen solution. However, the development of new computational fluid dynamics (CFD) technologies is making that choice easier by offering the best of both worlds, so that rapid simulations are possible on even the most complex of geometries. These new technologies are necessary to meet the challenge of increasing power and geometric density in electronic products, as well as the declining availability of thermal experts to work with these more complex designs.
Thermal Design Tougher as Power, Package Density Increases
CPU clock speeds have plateaued, limiting die-level power density to the order of 100 W/cm2. Designing electronic products with die-level power densities above 100 W/cm2 is verychallenging and expensive, so it’s actually packaging technology and cost limitations that are limiting CPU clock speeds. As a result, the trend has been to use multiple cores to process tasks in parallel and handle multiple tasks concurrently to deliver higher overall performance. This has resulted in power densities continuing to increase at the package, board, and system levels in many applications.
In some applications, such as mobile products, 3D IC packages are becoming more commonplace with the pressure to both shrink the height of IC packages and use stacked die. Although phone sizes have increased, which provides useful additional heat transfer area because ultimately the heat has to be either convected away to the air or conducted into the hand, that trend has more or less reached the limit of convenience in the latest touchscreen smartphones. More efficient materials to spread the heat provide more options, but they have an additional cost and weight penalty.Read the full article here.Editor's Note: This article originally appeared in the November 2013 issue of The PCB Design Magazine.