Thermal management of Telecom Switching Equipment

Tekelec is a leading developer of current and next-generation signaling and switching telecommunications solutions. To maintain our rapid time to market, it is sometimes necessary to begin prototype fabrication before all of the product requirements are fully defined. A recent example is that of a 1U rack-mounted fuse and alarm panel, which we developed with Trimm, Inc. During the course of design the amperage requirements more than doubled. We had to determine if the circuits on the power board could handle the increased current, or if a different approach would be necessary. It was critical to be sure of our direction because any late-stage design changes would have increased the risk of schedule delays and incurred higher costs. With this information, we used Flotherm to explore several different alternative solutions. Our goal was to find the best combination of fit and performance. We determined that a copper bus bar could be substituted with minimal redesign and schedule disruption. The bus bar would not only lower the dissipated power, it would also spread heat more effectively. Flotherm confirmed and quantified these theories. All this was accomplished within just a few days. The bus bar prototypes had a long lead time, so we were relying entirely on the accuracy of the thermal model to prevent further delay. When the new parts arrived, lab testing confirmed that they had a 30 C improvement over the original module temperature. The fuse panel was released on schedule, fully meeting the new power requirements.