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Using PCB Thermal Simulation in the Pre-Development Design Phase

Published Date
Author Cadence System Analysis

Key Takeaways

  • By conducting thermal analysis using a PCB thermal simulation tool, designers can avoid thermal hotspots and high temperature affected areas in PCBs at the pre-development stage.

  • From the PCB thermal simulation results, designers can see the overall heat dissipation in a circuit. 

  • As the thermal behavior of a PCB track influences the reliability, performance, and efficiency of a circuit, it is essential to study their thermal simulation results.

Circuit board layout

Careful thermal management of PCBs is critical to achieving the outstanding performance of a circuit. Improper heat and thermal management techniques limit the performance of a circuit, so it is imperative that meticulous thermal design starts at the pre-development stage. 

It can be a tedious task, however, PCB designers must check the effectiveness of their layout, thermal vias, and heat sinks in every design. Without this attentiveness, designers might miss hotspots or poor thermal design areas, and the emergence of unexpected heating areas might occur. 

The Benefits of PCB Thermal Simulation

The thermal behavior of a circuit is difficult to forecast manually. PCB thermal simulation is a boon to both the PCB design process and designers, as it predicts flaws in thermal management and provides a second chance to redesign the circuit for improved heat dissipation and heat transfer. 

During the PCB design process, designers need to know the heat dissipation of certain components to know whether to change the layout or include thermal vias or heat sink. It is not feasible to fabricate PCBs with different layouts, thermal vias, or heat sinks just to check whether the heat dissipation is within an allowable limit. PCB thermal simulations solve this problem by enabling designers to run different PCB layouts of the same circuit, and from those results, the designer can see the overall heat dissipation in the circuit and settle on the best thermal solution. 

In essence, PCB thermal simulation is considered a detection tool, enabling designers to identify poorly-managed thermal designs. Conducting thermal analysis using a PCB thermal simulation tool enables designers to do the following: 

  • Avoid thermal hotspots and high-temperature affected areas in PCBs at the pre-development stage. 

  • Understand information about the airflow, temperature distribution, and heat transfer in the PCB layout. 

  • Cost-effectively construct the PCB with an optimal layout. 

If the PCB thermal simulation results are good, then the designer can feel confident that they have a thermally sound design.

Applying the Results of Thermal Simulation

When using PCB thermal simulation, a designer transfers the optimal design for fabrication and results to achieve the best product design. Drastic design changes can be made with PCB thermal simulation, and the designer can determine the design that best supports thermal limits. If a design modification supports the thermal requirements of a PCB, then it is made a permanent part of the design, otherwise, it is removed. 

A PCB layout will be illustrated in different colors in simulation results, and the effect of layout design modifications, thermal vias, and heatsinks can all be seen in the results. A single PCB design can be simulated with or without thermal vias and heat sinks, and you can choose between them by comparing heat dissipation profiles. In PCBs utilizing semiconductor devices, the temperature at semiconductor junctions can be determined, along with the temperature at PCB tracks. 

In general, PCB thermal simulation can do the following:

  1. Identify the thermal problems in a PCB layout.

  2. Check for thermal interferences in a layout. 

  3. Check the heat release pattern by changing the wiring coverage ratio.

  4. Check the arrangement of thermal vias.

  5. Check the performance of the heat sink and optimize its design.

  6. Reduce the size of a PCB by taking into account the thermal requirements.

  7. Observe the effectiveness of cooling methods such as natural air and forced air cooling.

  8. Check the feasibility of heat dissipation with circuit enclosures or casing.

The Importance of Thermal Simulation of PCB Tracks

Miniaturization and increased power density in electronic circuits have adversely affected PCB track geometry. Miniaturization has led to decreased track width and the incorporation of more components in a limited area. The geometry of PCB tracks is a limitation to high current flow, as current flow increases the heating in the track due to the Joule-Lenz effect and voltage drop. The thermal vulnerability of a PCB requires designers to consider geometric parameters such as width and thickness. As the thermal behavior of a PCB track influences the reliability, performance, and efficiency of the circuit, it is essential to study the thermal simulation results of PCB tracks.

PCB thermal simulation is necessary to achieve efficiency, and reliability, and to satisfy all thermal requirements in your layout design. By properly applying simulation results, designers can enjoy an immense reduction in component damage from heating and overrating of heat sinks. Additionally, PCB thermal simulation makes the circuit design process cost-effective by ensuring designers choose the best layout on a smaller PCB surface area and employ effective thermal management techniques. 

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