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Israel-based ECI Telecom designs telecommunication platforms and solutions for carriers, cable and
wireless providers, utilities, and government and defense organizations worldwide. For these customers,
thermal reliability is critical and ECI depends on CFD analysis to achieve it.
ECI engineers initially design chassis and select fans based on the expected power dissipation of
components. They then use Coolit to optimize heatsinks, determine component placement, predict junction
temperatures, and assess the operating performance of fans.
Such generally effective approach proved inadequate for one mother-daughter board combination. The high
powered combo was housed in a small enclosure that made it difficult to dissipate the heat adequately. In
addition, the design contained large vendor modules that blocked air flow across the cards. No amount of
fan tweaking or component selection and placement optimization could compensate for the expected 300W
thermal load, and the unit was exceeding its temperature design limits.
After some deliberations ECI's thermal engineers came up with a new approach: add a heat pipe
to draw heat from the components on top of the main card. The heat is then transfered to main
card's backplane connector area where there was adequate real estate to mount a heat sink. Using Coolit,
ECI optimized the component placement on the mother-daughter board and determined the optimum spacing
between the boards. Next, the proposed design including the heat pipe and an off-the-shelf heat sink was
optimized in Coolit. The Coolit analysis predicted the new design would achieve the desired results. The
design was independently confirmed by the vendor who built the heat sink and embedded heat pipe system.
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