Is It Getting Hot In Here? Why Thermal Is No Longer A Signoff Problem

Applying the appropriate level of simulation and abstraction at each stage of the design process is key to effective thermal analysis.

AI, high-performance computing and advanced semiconductor packaging have pushed power density higher, and that means managing heat is becoming one of the most consequential challenges in electronic design.

The issue is no longer simply how to cool a chip after it has been designed. Thermal behavior now affects decisions spanning device performance, package architecture, mechanical stress, reliability, floor planning and ultimately system performance. So engineering teams must shift thermal analysis to earlier in the design process as they consider a much broader multi-physics strategy.

Traditionally, engineers could isolate and analyze many physical effects separately. Electrical performance could be evaluated in one environment, thermal behavior in another and mechanical stress in another and so on. But with increasing integration, a change intended to improve performance in one domain can create unintended consequences elsewhere. Higher power can increase temperature; temperature can change electrical behavior; and thermal expansion can introduce mechanical stress that ultimately affects reliability.

This is particularly worrisome when it comes to chiplets, 3D-ICs and other advanced packaging architectures. Multiple dies, interconnects, substrates, materials and cooling approaches interact within a tightly integrated structure. Designers need to understand not only what happens within an individual die but how the entire assembly behaves as a system.

And addressing this means examining both accuracy and scale. The engineer developing a chip may need detailed information about localized behavior and potential hotspots. A package engineer needs a different level of abstraction, while a system architect may need to evaluate thermal and performance tradeoffs across an even larger environment. Simulating every element at maximum fidelity throughout the entire system would be computationally impractical.

The answer is not simply more simulation. It is applying the appropriate level of simulation and abstraction at each stage of the design process. Techniques such as reduced-order modeling and superposition can help engineering teams scale analysis while preserving the information needed to make architectural decisions. These techniques provide each engineer with the fidelity required for the task while maintaining connections between the physical domains that influence one another.

This also changes when multi-physics analysis needs to occur. Waiting until final verification to discover that a floor plan creates an unacceptable thermal or mechanical condition can lead to expensive redesigns or even a complete (and expensive) design re-spin. If engineers bring multi-physics analysis into architectural exploration and floor planning, they can evaluate performance, package size, thermal behavior and reliability together, when there is still flexibility to make meaningful changes.

AI and agentic engineering workflows offer another opportunity to accelerate this process by using Model Context Protocol (MCP) to help orchestrate increasingly complex tools, models and engineering data. But AI does not eliminate the need for trusted physics-based simulation. AI-generated decisions can be difficult to trace, and models can make mistakes. Engineering teams therefore need workflows that combine automation with reliable simulation and sufficient visibility into how results are produced.

This growing thermal challenge is part of a larger transformation in electronic design. Electrical, thermal, mechanical and other physical effects can no longer be treated as isolated disciplines. They are interconnected elements of the same engineering problem.

Keysight’s goal is to enable engineers to bring these domains together earlier in the development process, applying the right physics, fidelity and automation at the right time. By shifting multi-physics analysis left – from final verification toward architecture and design exploration –engineering teams can identify problems sooner, make better-informed tradeoffs and increase confidence that increasingly complex electronic systems will perform as intended before committing to physical hardware.

So is it getting hot in here? Absolutely. But with the right approach to design exploration and analysis, it doesn’t have to be your problem.

Chris Mueth

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Chris Mueth is director of new markets management in the Keysight EDA Software Solutions business.