Using the new "Bottleneck" and "Shortcut" functions within FloTHERM 9, the CamSemi design team found a practical, cost-effective way to prevent heat buildup in their phone charger IC as well as the enclosure that housed it - all while meeting a very stringent development schedule.
“Developing a series of physical prototype packages for our IC for new-generation 5-Star mobile phone chargers would have been very time-consuming and costly without FloTHERM 9. Thanks to simulation with FloTHERM 9 and its new Bottleneck and Shortcut features we were able to avoid weeks of prototype development for each design iteration.”
Catriona McKay, CamSemi Program Manager
Cutting-Edge Power Conversion IC Design Poses a Thermal Challenge
CamSemi, an industry leader in power management IC technology, was developing a new charger chip for a major telecom producer's next-gen mobile products. The device contained not only low-voltage control circuitry but also power switches that handled high current. The new IC was an innovative "game-changer" that would meet tough performance requirements as well as EnergyStar standards for improved power conversion efficiency and safety-related compliance.
One key concern was heat dissipation: would it be possible to find an outlet for the heat produced within the new high-power chip? The design process would almost certainly challenge the project's very stringent schedule. Historically, design iterations (including prototype rework) had taken weeks or even months to complete. In effect that gave engineers just a couple of turns to optimize the design.
Thermal simulation offers a solution to problems like this but until recently even the most advanced tools could only produce thermal data showing the distribution of temperature values within an environment. Though useful, this data lacks any clues about why hot areas are hot, and how best to solve heat problems.
FloTHERM Delivers Thermal Answers, Not Just Data
The design team chose Mentor Graphics FloTHERM 9 electronics cooling software, with its newly-introduced "Bottleneck" and "Shortcut" features. FloTHERM is a proven CFD tool widely used in electronic design applications. Its Bottleneck (BN) field pinpoints areas in which a lot of heat flows and where that heat flow is restricted, while the Shortcut (SC) field identifies areas where the insertion of a new heat flow path can conduct heat more quickly to cooler areas, reducing the temperature rise.
Optimizing an IC's Heat Paths, Inside and Out
FloTHERM 9 enabled the CamSemi team to predict thermal behaviors inside the IC package, a feat impossible to perform adequately with thermocouples, as well as outside the chip. The initial thermal findings guided several refinements to the design. In subsequent design iterations, the BN field results were used to validate good proposals and - equally important - dismiss bad ones, avoiding unproductive time and effort. Ultimately the BN and SC fields working in complementary fashion revealed an effective heat bypass area underneath the chip. CamSemi engineers were able to deliver a proven, optimized design to the final prototype and testing phases.
“The value of FloTHERM 9 is in the time and the cost it saved us when developing an IC for a new generation of Energy Star-compliant mobile phone chargers. The Bottleneck and Shortcut features within FloTHERM 9 helped us resolve some difficult thermal issues quickly, and kept our project on track to meet our customer's very aggressive deadline.”
Catriona McKay, CamSemi Program Manager
CamSemi is known for its innovative work in developing the specialized semiconductor components used in chargers and adapters for mobile devices. The company's approach is to offer advanced power management ICs that will help manufacturers find faster, simpler and lower cost ways to develop more energy-efficient power conversion products. http://www.camsemi.com/corporate/index.htm