Reliability Thermal Test

Created: 5/17/2020Last Updated:5/17/2020


Thermal reliability ensures electronic products or equipment operate under a wide range of temperature conditions without affecting user experience.


Product performance

    • Thermal Throttling happens when CPU temperature governor starts to downscale CPU frequency or wireless power amplification to limit over all system power output.
    • Proper thermal design has NO thermal throttling under any practical system load conditions.

Product Safety

    • Product plastic or metal skin temperature Must be under maximum allowed temperature under worst thermal load conditions
      • Note: There is a safety regulatory limit to ensure product safety; however product designers should have more stringent limits to improve product competitiveness.


  • Define power budget for each high power output components such as processor and and wireless chips and amplifiers
  • Use heat sinks on large ICs such as processor.
  • Use thermal interference materials (TIM) to pull heat from IC to the surface effectively
    • Common TIM: thermal pad, thermal glues, graphite sheet, and thermal pipe.
  • Connect component ground pads to the main ground planes to increase thermal relief areas.

Summary & Conclusion

  • Thermal reliability ensures product operate under a wide range of temperature and humidity under any thermal load conditions.
  • Electronic product surface temperature Must under a safety limit
  • Electronic product performance Must not thermal throttle to affect user experience.
  • Develop a power budget is essential to understanding and limit thermal hot areas within a PCB board
  • Use thermal interference materials (TIMS) to pull heat out of product to ambient air more effectly

Thermal design is critical to product long term operability and user experience .