Thermal Simulation and Analysis Software for Printed Circuit Design

Zachariah Peterson
|  Created: March 22, 2021

Thermal management in your printed circuit board is all about directing heat from hot to cool areas, ultimately reducing the temperature and producing a more even temperature distribution in your printed circuit board. Your arrangement of components and other thermal design decisions can be evaluated with thermal analysis software. This helps you identify areas of your circuit board that will operate at high temperature and determine the appropriate design changes to reduce the temperature of your substrate and components.

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Thermal management is a vitally important design topic, and you’ll need to examine how heat sources in your board will affect the temperature of your printed circuit board. Each printed circuit and component has a well defined thermal conductivity value, and the right thermal analysis package will allow you to simulate how the temperature of your board changes during operation.

What Does PCB Thermal Analysis Software Do?

In the simplest sense, PCB thermal analysis software is used to calculate the steady state temperature distribution in your printed circuit board. This also allows you to visualize heat transfer throughout your circuit board, as heat will naturally flow from hot to cold regions of your board. If you need to determine whether your board will run at an excessive temperature during operation, then you should use thermal analysis software.

Some Design Choices for Thermal Management

The temperature distribution in a PCB can be calculated by solving the heat equation. This requires assuming the amount of heat generated by different components and calculating the temperature increase in different regions of the board by solving the steady state heat equation. This requires defining the thermal conductivity (or if you like, thermal resistance) of your electronic components and substrate.

Heat generation can also be calculated from electrical models. The current and voltage drop across components in your circuit board can be calculated using SPICE or IBIS models, and the power dissipated in your board is converted to heat. The temperature coefficient of all components is defined in your simulator, which defines how their temperature will change during operation.

Methods for determining the temperature distribution in printed circuits are well-known and can be accessed in many different simulation packages. The best PCB thermal analysis software will access your design data directly and will automatically build a model from your layout. This eliminates the need to import your design into an external application for simulating the thermal behavior of your PCB.

PDN Analyzer in Altium Designer

Thermal and power dissipation simulation output with the PDN Analyzer in Altium Designer

Applications of PCB Thermal Analysis Software

Thermal analysis software is excellent for verifying design choices and the effectiveness of thermal management measures. The equilibrium temperature of your is related to the power dissipated by components and conductors throughout your board. The best PCB thermal analysis software will provide power distribution results and temperature distribution results in a single simulation package, allowing you to examine both aspects of your board’s performance simultaneously.

Using Analysis Results to Determine Redesigns

When looking at your simulation and analysis results, you should aim to identify areas where the temperature of your system increases beyond the maximum temperature specified by your component manufacturer. This can help you determine if you should implement a passive or active cooling mechanism to reduce the temperature. Among the various passive methods, using a heat sink on top of a large component and placing thermal vias below the component are the two easiest ways to remove heat from your PCB.

When looking at your PDN Analyzer output, you should try to identify areas in conductors where power dissipation and temperature are greatest. You should use heavier copper in these areas in order quickly spread heat away from a concentrated area. Although the level heat dissipated in the region will not change, the temperature distribution in the steady state will be lower through the use of heavier copper.

Screenshot of the layer stack manager in Altium Designer

Stackup design in Altium Designer

How to Choose PCB Thermal Analysis Software

There are many thermal analysis software packages on the market, but none of these will integrate directly with your PCB design tools. This forces you to manually export data from your design software and import it into your simulator. Instead of working with fragmented design and analysis programs, your printed circuit design software should include a thermal simulation module alongside your layout tools.

Integrated Design and Thermal Analysis in Altium Designer

Altium Designer is the only printed circuit design platform that integrates your design, layout, management, and simulation features into a single application. You won’t have to adapt a third party application into your workflow. You’ll have access to a complete design and analysis solution in Altium Designer.

The thermal simulation and analysis tools in Altium Designer are accessible alongside your design features in the same application. Your design data can be immediately imported into your simulation tools, allowing you to easily place components, route your electrical connections, and simulate heat transport without exporting design data to an external program. You’ll have all the design features you need to implement a thermal management strategy for your next product.

Altium gives you the resources you need for successful printed circuit design and analysis. You’ll have access to design tutorials, the AltiumLive forum, podcasts and webinars with industry experts, an extensive knowledge base with plenty of design tips. With the comprehensive suite of design tools to the resources you need for success, Altium has set a new standard in the printed circuit design software industry.

About Author

About Author

Zachariah Peterson has an extensive technical background in academia and industry. He currently provides research, design, and marketing services to companies in the electronics industry. Prior to working in the PCB industry, he taught at Portland State University and conducted research on random laser theory, materials, and stability. His background in scientific research spans topics in nanoparticle lasers, electronic and optoelectronic semiconductor devices, environmental sensors, and stochastics. His work has been published in over a dozen peer-reviewed journals and conference proceedings, and he has written 1000+ technical blogs on PCB design for a number of companies. He is a member of IEEE Photonics Society, IEEE Electronics Packaging Society, and the American Physical Society, and he currently serves on the INCITS Quantum Computing Technical Advisory Committee.

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