What is the Physics of Failure and Does it Increase Reliability?

November 12, 2019 Cadence PCB Solutions

Physics of failure written over graphics of data and engineering


The laws of physics play a vital role in the establishment of the fundamentals of science itself. It is the countless pursuits in the field of research that form the basis for our laws of physics. In general, the laws of physics consist as various research or some form of modification to existing laws and theoretical analysis. It then makes sense that, in a world dominated by success and failure, there is a class of physics of failure. 

Overall, physical laws conclude on the basis of long scientifically-focused observations and experiments. Furthermore, these experiments receive acceptance as fact only after repeatable results under different circumstances. As a whole, the world as we see it and understand it is primarily due to our laws of physics.

This overwhelming understanding of processes and mechanisms is also in use in the field of electronics (PCBs). Electronic devices and PCBs with their high demands for speed, accuracy, reliability, and functionality, benefit significantly by this level of understanding. In short, to best understand how a device works, one must understand what causes it to fail.

What is the Physics of Failure?

Physics of failure (POF) is an invaluable technique that encompasses the intricate practices of Design for Reliability. The method leverages the understanding and knowledge of the processes and mechanisms that generate failure. This, in turn, affords you the ability to improve product performance and predict reliability.

The POF uses a science-centered approach to reliability that utilizes 3D-modeling and simulation to seamlessly design dependability into your electronic devices as well as PCBs. It also helps you to better understand the performance of your systems and reduce decision errors during the design process. This same approach also carries over to the end consumer after the device is in use in the field.

The POF models its approach on the basis of root causes of failure, such as corrosion, fatigue, fracture, and wear or other stressors. Its overall approach to the design and development of a reliable product, emphasizes the prevention of failure. This, of course, is on the basis of knowledge on the root cause of failure mechanisms.

The History of the Physics of Failure

I learned years ago while working in the field of engineering (US Navy), that reliability and performance are paramount to defense applications. Especially when you consider the fact that if the device you are using fails means loss of life. This really puts the word reliability into perspective. That is also why defense engineers are some of the first to embrace the field of reliability engineering.

When reliability engineering began, its focus was on metal fatigue and fractures. As the strategies improved, design for reliability (DFR) encouraged a shift to electronics reliability using prediction, simulation, and testing tools. This DfR methodology serves as the basis for the physics of failure (POF) approach that is common in many industries today.

Geothermal testing device

Every day design challenges can always boil down to reliability.


As I alluded to earlier, this methodology has a foundation heavily supported by the knowledge of the relationships between requirements, the physical characteristics of the product, and their variations in the manufacturing process. Physics of failure also considers the reaction of the product elements and materials to stressors as well as interaction under loads. In summary, this technique evaluates the loads or stressors influence on the fitness of use in reference to the use conditions and time (length of use).

The Future of Physics of Failure

POF is a scientific discipline that determines the root causes of failure for electronic, electromechanical, or electrical devices (components). This invaluable evaluation tool has revolutionized the field of electronics and engineering as a whole. Also, with all of the improvements brought about by POF, the future possibly holds even more significant achievements.

Better designed and more complex PCB designs are no longer just the trend. Today’s consumers demand that the devices they use are faster, better performing, and more reliable than they were the year before. This is evident by companies like Apple and Samsung, who are feverishly competing to produce a newer, better model of their respective smartphones year after year. Faster, better performing, and more reliable electronics are exploding onto the scene in every industry, including defense, consumer products, automotive, and healthcare.

This ever-evolving landscape of electronics is a direct response to the demands for the Internet of Things (IoT) devices, electrification, and Autonomous transportation. So, with all of these new and not so new technologies melding together, there is also a new level of possibilities for failures. That is where POF will prove to be invaluable.

Advancements in Technology Fuels the Need for Physics of Failure

As technology continues its constant evolution, the components in use now find themselves in unfamiliar territory. For example, years ago, a computer processing system was only found in, well, a PC. However, in today’s automobiles, this is commonplace. In fact, most vehicles have more complex processing systems than your average PC.

This brings me to this point; they are placing components like processors into devices that have reliability standards that exceed a processor’s expectation. Technological advancements only increase the demand for POF techniques to be fully realized in almost every industry.

However, in terms of the future of POF, I have one more example; autonomous vehicles (taxis). The average automotive electronic modules are usually intended and validated for approximately 5,000 to 9,000 hours of operation over a 10 to 15-year period. However, the upcoming autonomous taxis are expected to operate 22 to 24 hours a day. When calculated, that is 32,120 to 35,040 hours of operation in just four years. So, the need for reliability is critical, and the use of POF techniques is the only viable way to design for the future.

Printed circuit boards and ICs being manufactured in futuristic assembly line

Having greater design confidence in reliability and validation is paramount for future technologies.


POF is the scientific approach that also affords you the luxury of scalability. The future is still not written, but POF is the one-size-fits-all technique that can accommodate the changing demands and landscape of the field of electronic devices (reliability).

Future planning has never been easier than with Cadence’s suite of design and analysis tools. Between reliable layout and production options provided in Allegro PCB Designer and a complete field of thermal, signal, and power analysis functions working in tandem with your layout, you’ll be sure to meet any design challenges with ease. 


About the Author


Follow on Linkedin Visit Website More Content by Cadence PCB Solutions
Previous Article
PCB Design Tools to Promote Engineering Team Collaboration
PCB Design Tools to Promote Engineering Team Collaboration

For designers to stay ahead of the technology development race, they will need concurrent PCB design tools ...

Next Article
How Sustainable Electronics Materials are the Future of the PCB Industry
How Sustainable Electronics Materials are the Future of the PCB Industry

The use of sustainable electronics materials is environmentally friendly, provides lower manufacturing cost...