The Four Most Common Causes of Failure of Electronic Circuits

October 4, 2019 Cadence PCB Solutions

Neon donut on red background

 

I am sure you know the slogan, “America Runs on Dunkin.” Even though it is only a slogan, there is a definite degree of truth to that statement, according to Dunkin’s 2nd Quarter 2019 sales report. However, the world itself, including America, runs on PCBs.

Printed Circuit Boards (PCBs) are found in your smartphones, your game consoles, and your laptops, just to give you an idea of the scope of their usage. And, at the heart of every PCB resides an electronic circuit(s) of some kind. These electronic circuits are an integral part of every PCB and so is the inevitability of electronic circuit failure.

The overall usage of PCBs makes the failure of their electronic circuits all the more encompassing to your everyday personal and professional lives. With such an overwhelming integration into almost every electronic device, being able to recognize the commonality and trends in electronic circuit failure is paramount.

Without further ado, I will discuss four of the most common causes of failure of electronic circuits.

1. Component Defects in Electronic Circuit Failures

As I alluded to earlier, electronic circuit failures do follow a trend. In the initial stages of the life of an electronic circuit, component failures are more common. Although this failure rate tends to drop off substantially as the device the electronic circuit resides in, is used.

These defects that ultimately causes electronic circuit failure can be attributed to defective components used in the design. The silver lining, if there is one, is the fact that these types of failures usually transpire during the PCB assembly process or shortly thereafter.

More importantly, these defects in your electronic component or circuit can be latent (meaning the PCB remains functional but suffers downgraded reliability) or catastrophic (meaning permanent damage has been done.)

Other Potential Defects That Cause Electronic Circuit Failures

 Misaligned layers:

PCB stack-up configuration is one of the most important aspects in achieving the best possible performance of a product. A poorly designed substrate, with inappropriately selected materials, can degrade the electrical performance of signal transmission increasing emissions and crosstalk. It will also make the product more susceptible to external noise. Please note that misaligned layers can be the result of improper stack-up files, and it’s best to go back and ensure that your stack-up is properly managed before trying to send the circuit board to assembly and fabrication.

Crossed signals can result in signal integrity issues, improper impedance, and jitter.

2. Environmental Factors That Cause Electronic Circuit failures

If you have resided in a warm-weather climate (Florida) for the majority of your life, then you can relate to a new recruit (Me) serving in the Navy in Great Lakes, Illinois experiencing culture shock during his first Chicago, winter. I can attest that temperature is a disruptive environmental factor.

Well, temperature is also a disruptive environmental factor when it pertains to electronic circuits. Temperature changes can indeed cause an electronic circuit to fail and in turn, cause a PCB’s malfunction. As you may know, with temperature changes, you will experience expansion and contraction of the PCB. These expansions and contractions, in turn, brings about the potential risk of a warped board and damage to solder joints.

Another equally devastating environmental factor is moisture. If moisture is introduced to your electronic circuits, it can cause rust, oxidation, and corrosion.

 

Pile of old monitors molding with age

Environmental strain can significantly shorten electronic lifespans. 

 

A third environmental factor that has proven to be an enemy of electronic circuits is build-up. The build-up of debris such as dust, dirt, hair, fibers, and even insects can also contribute to electronic circuit failure. This build-up over time can clog up fans thereby preventing proper ventilation and heat dissipation. This, of course, leads to overheating and electronic circuit failure.

3. How Design and Component Quality Effects Electronic Circuit Failures

Whether building a PC or installing a car stereo, the quality of the components used affects the finished product. This is equally true with the design used. For example, if you are running new (High-quality) audio cables (RCA) from the source unit to your new 4-channel amplifier, placement is crucial. If placed too close to any of your 12-volt power lines, you will introduce electrical noise into your sound system.

These same practices must be adhered to when designing PCBs. For instance, the improper placement of components on your PCB, due to lack of space. First of all, this is a design issue and secondly, this will undoubtedly cause overheating (Burnt Components) as well as electronic circuit failure.

In addition, the use of inferior or counterfeit components can and will lead to electronic circuit failure as well. Other pitfalls to be mindful of are traces and pathways placed too closely together as well as poor connectivity between circuit boards and insufficient board thickness. These are just a few examples of things that can go wrong at the design and manufacturing stage.

Although the aforementioned concerns are all important, there is one other cause of electronic circuit failure that I consider to be all-encompassing. That my friend is solder.

Solder is an essential ingredient in the creation of electronic circuits and the PCB process. It is what maintains the contact between a component and the actual circuit, but it can occasionally become contaminated and result in electronic circuit failure. For instance, if there is too much moisture in the solder, it can become conductive and cause short-circuiting.

4. The Effects of Age on Electronic Circuits

I am sure you have heard the saying, “With age comes wisdom.” And for the most part that is true, for humans. However, for electronic circuits, with age comes electronic circuit failure. This is an inevitability of all electronic circuits regardless of the quality of the build.

The good news here is, the components that make-up your electronic circuits can usually be replaced. In addition, the necessary replacements can be done at a fraction of the price of a newly manufactured PCB.

Although age will eventually affect the functionality of your electronic circuits, proper design and methodology is the most effective way of ensuring a longer lifespan for your electronic circuits and PCBs.

 

Power supply box short-circuiting

Though it’s a pain, it is good to replace old circuits with fresher technology after too many years.

 

Although durability and quality are the quintessential buzzwords in almost every industry today, electronic circuit failures and resultant PCB failures do occur. Unfortunately, it is not always easy or simple to trace the exact cause of an electronic circuit failure in every instance.

However, knowing the most common causes of these failures will aid you in a quicker diagnosis and possibly lead to better overall designs. Keep in mind, that other stressors such as EOS (electrical overstress), ESD (electrostatic discharge), EMI (electro-magnetic interference), and thermal overstress can also cause electronic circuit failure as well.

The bottom line here is, proper design and proven methodology is key to preventing or delaying electronic circuit failure. This is where Cadence can help. At Cadence, you will find the resources, experience, and expertise to help you meet your broader business goals.

OrCAD PCB Designer is there to enable a schematic, layout, and post-layout process that is both efficient and consistent. With a strong and customizable DRC engine as well as other great tools and augmentation options like auto-interactive routing and the IPC-2581 format to make stackups and documentation easy, you’ll be sure to find any potential hazards in your designs early and easily.  

If you’re looking to learn more about how Cadence has the solution for you, talk to us and our team of experts.

About the Author

Cadence PCB solutions is a complete front to back design tool to enable fast and efficient product creation. Cadence enables users accurately shorten design cycles to hand off to manufacturing through modern, IPC-2581 industry standard.

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