Customer Brief: Credence Systems

Credence Systems Corp., a world leader in the manufacturing of automatic test equipment (ATE) used in the semiconductor industry, has found that using CFdesign engineering simulation to predict the system thermal characteristics at the earliest design stage can help shorten the overall design process, improve the quality of the final design, and increase the productivity of the thermal design engineer.

The complex architecture of next generation test heads made it impractical to accurately predict board and system level performance discretely. The goal, therefore, was to develop a CFD model that accurately predicts both system and board-level performance concurrently.

The company's engineers chose to use CFdesign to perform the thermal and flow analysis on the test head. "I liked the ease with which I could import complex geometry into CFdesign," says Venkat Gaurav, a senior mechanical engineer at Credence. "Models built in Autodesk Inventor required no editing or clean-up at all prior to launching the simulation and CFdesign automatically meshed the model too."

CFdesign predictions were compared with actual experimental results. Thermocouples were attached to the chips modeled in the simulation and case temperatures were measured and recorded. Air velocities were also measured at various locations using airflow sensors. The measured temperatures compared well with the simulation predictions and were in most cases within 3.0oC.

The results proved to be very useful in making design decisions regarding board layout based on the board-level thermal characterization and in sizing and selecting fans for air cooling based on the system level flow characterization. "I was extremely pleased with how quickly I could set up a model for analysis and watch its progress during the course of the analysis. CFdesign lends itself very well for performing 'what-if' analyses," says Gaurav.