Thermal gradient of a cellphone using the Celsius Thermal Solver (Source: Cadence)

By combining finite element analysis with computational fluid dynamics, designers can perform complete system analysis using a single tool.

Today’s modern electronic designs require ever more functionality and performance to meet consumer demand. These requirements make scaling traditional, flat, 2D-ICs very challenging. With the recent introduction of 3D-ICs into the electronic design industry, IC vendors need to optimize the performance and cost of their devices while also taking advantage of the ability to combine heterogeneous technologies and nodes into a single package. While this greatly advances IC technology, 3D-IC design brings about its own unique challenges and complexities, a major one of which is thermal management.

To overcome thermal management issues, a thermal solution that can handle the complexity of the entire design efficiently and without any simplification is necessary. However, because of the nature of 3D-ICs, the typical point tool approach that dissects the design space into subsections cannot adequately address this need. This approach also creates a longer turnaround time, which can impact critical decision-making to optimize design performance. A more effective solution is to utilize a solver that not only can import the entire package, PCB, and chiplets but also offers high performance to run the entire analysis in a timely manner.

Celsius thermal management solutions
Cadence offers the Celsius Thermal Solver, a unique technology integrated with both IC and package design tools such as the Cadence Innovus Implementation System, Allegro PCB Designer, and Voltus IC Power Integrity Solution. The Celsius Thermal Solver is the first complete electrothermal co-simulation solution for the full hierarchy of electronic systems from ICs to physical enclosures. Based on a production-proven, massively parallel architecture, the Celsius Thermal Solver also provides end-to-end capabilities for both in-design and signoff methodologies and delivers up to 10X faster performance than legacy solutions without sacrificing accuracy.

By combining finite element analysis (FEA) for solid structures with computational fluid dynamics (CFD) for fluids (both liquid and gas, as well as airflow), designers can perform complete system analysis in a single tool. For PCB and IC packaging, engineering teams can combine electrical and thermal analysis and simulate the flow of both current and heat for a more accurate system-level thermal simulation than can be achieved using legacy tools. In addition, both static (steady-state) and dynamic (transient) electrical-thermal co-simulations can be performed based on the actual flow of electrical power in advanced 3D structures, providing visibility into real-world system behavior.

Designers are already co-simulating the Celsius Thermal Solver with the recently acquired Future Facilities’ 6SigmaET electronics thermal simulation software, which provides state-of-the-art intelligence, automation, and accuracy. The combined workflow that ties Celsius FEA thermal analysis with 6SigmaET CFD results in even higher-accuracy models of electronics equipment, allowing engineers to test their designs through thermal simulations and mitigate thermal design risks.


As systems become more densely populated with heat-dissipating electronics, the operating temperatures of those devices impact reliability (device lifetime) and performance. Thermal analysis gives designers an understanding of device operating temperatures related to power dissipation, and that temperature information can be introduced into an electrothermal model to predict the impact on device performance.

The robust capabilities in modern thermal management software enable new system analyses and design insights and empower electrical design teams to detect and mitigate thermal issues early in the design process—reducing electronic system development iterations and costs and shortening time to market.