By collecting and analyzing more relevant measurement data, electronic cooling systems can be designed for improved performance, reliability, and cost. It’s essential these measurements be as accurate as possible. Critical data points include component temperature, air temperature, air flow rate, and often air pressure. Accuracy becomes even more important when performing accelerated testing as seen in this post.
Research-grade instruments and specialized sensors, properly calibrated and operated, can measure chip temperatures and surrounding elements, such as local airflow. Separate instruments can be used to quantify specific conditions, but more real-use data is obtained when all points are collected simultaneously. Taken over a range of time and conditions, simultaneous measurements provide more accurate, actionable information. They also reduce the cost and set-up time for multiple studies.
Accelerated Product Reliability Testing
Reliability testing at different temperatures and conditions is commonly performed to identify expected product life. When an electronic system is running, it continuously experiences temperature and power cycling. These fluctuations are typically normal, but should be factored into a comprehensive thermal profile study.
It’s not practical to wait years to see if a component fails. Accelerated life testing provides faster predictions. A commonly used predictive tool is the Arrhenius model shown below.
Accelerated life testing using the Arrhenius model is a method for predicting how long a product will last under normal conditions by running it at elevated temperatures for a shorter time. The temperature increase speeds up the same failure processes that would eventually occur in the field—compressing years of life into weeks of testing.
Accelerated life testing Arrhenius calculators can help estimate field lifetime, test duration, acceleration factors, activation energy, and field failure rates. These tools are useful when real-time qualification can’t be done. This is typical with electronic components and devices that need fast market introduction. One such calculator is found here: Accelerated Life Test Arrhenius Calculator. [1]
The Arrhenius Model handles pure thermal stress, while the Eyring Model includes temperature plus other active forces like humidity or voltage. [1,2]
Highly Accurate Thermal Instruments
Besides its design, a thermal instrument’s construction and calibration should be high quality, and not a source of more errors. Accurate, research-grade instruments are essential for valid engineering practices. Without them, reliability predictions for a new product are actually less reliable themselves.
Here are some of the ATS instruments available for temperature and velocity measurement and providing the highest-quality thermal reliability test results.
Conclusion
Temperature has a significant effect on reaction rate and the subsequent reliability prediction. Small errors in temperature and airflow measurements can significantly impact reliability predictions. Such errors typically occur in the measurement process or from using inaccurate instruments.
If thermal data is inaccurate, outcomes can include over-designed systems, cost overruns, and products not shipping.
Laboratory-quality thermal instruments can reduce or eliminate measurement and calculation mistakes, leading to higher quality, faster to market and ultimately lower cost products. Just as important, collected data needs to be correctly interpreted. Expert thermal engineers can do just that with data provided or that they obtain themselves.
More information on these topics can be seen at these ATS videos:
How to Properly Measure Air Velocity in Electronic Systems [Link] [3]
How to Perform and Understand Temperature Measurement within Electronic Systems [Link] [4]
stageVIEW Software Demo [Link] [5]
References
- Firgelli Automations, https://www.firgelliauto.com/blogs/calculators/accelerated-life-test-arrhenius-calculator
- NIST, https://www.itl.nist.gov/div898/handbook/apr/section1/apr152.htm
- Advanced Thermal Solutions, Inc., https://vimeo.com/reviews/a4e9a72d-d228-489f-8edb-a98e440a8ef1/videos/113427506
- Advanced Thermal Solutions, Inc., https://vimeo.com/reviews/63784f1b-a32d-4f90-86b1-5bf362715619/videos/113432468
- Advanced Thermal Solutions, Inc., https://www.youtube.com/watch?v=Lx5NlAI5TuM