“Winning isn’t everything, but it’s the only thing” is a famous quote attributed to legendary Green Bay Packers head coach, Vince Lombardi. He elaborated that “Winning is not a sometime thing; it's an all the time thing. You don't win once in a while; you don't do things right once in a while; you do them right all of the time. Winning is a habit. Unfortunately, so is losing.” In other words, losing is not simply due to bad luck. Instead, failure is the result of bad habits.
The same can be said about the failure of PCBAs to meet their performance objectives reliably throughout their projected lifecycles. The majority of the time when a board fails, the root cause can be linked to one or more components. The optimization of the selected components for your design is essential for good PCBA development and to prevent shipping boards with bad or inferior components. However, making the best selections is but one of the necessary habits for avoiding the most common electronic components that fail. Before considering other actions that need to become routine for reliable board performance, it is necessary to know what types of components are most prone to failure.
What Are The Most Common Electronic Components That Fail?
One of the world’s most trusted electronics suppliers, Digi-Key Electronics, lists nearly 12,000,000 electronic components. The overwhelming majority of these are components that mount on or attach to circuit boards. Many components are relatively new to the market, which means there is limited (if any) data on failure rates. Additionally, there is a tendency to replace entire boards instead of troubleshooting them to uncover and replace failed individual components. These and other reasons make it virtually impossible to compile an accurate and comprehensive database of the rate of failure for individual components.
Instead of relying on individual component failure rates, it may be more useful to classify components according to failure modes or source of failure. Generating a list of component failure types that can be practically utilized would improve quality control methods for electronics manufacturing. Such a list of the most common types of electronic components that fail is presented below.
#1 Unprotected Components
Circuit boards are subjected to various conditions before being installed for operation. These include board fabrication, PCB assembly, shipping and storage. During all of these phases, the possibility of contamination exists. For the manufacturing of critical boards—such as those used in some medical device applications—ionic contamination can be a major problem. During shipping and storage, unprotected boards are subject to oxidation and other contamination that may eventually lead to a premature board and/or component failure.
#2 Moisture Sensitive Components
One of the major sources of contamination that threaten electronic components on circuit boards is moisture. Moisture can be acquired during component and/or board manufacturing. Additionally, condensation can occur on the board and within component packages. This is most common when boards are stored in packaging where internal temperatures are colder than the external environment. Certain components are more susceptible to moisture than others and this should be a consideration when making your selections.
#3 Temperature Sensitive Components
PCBAs are installed everywhere these days. This includes extreme environments where temperature, pressure and corrosion can affect the operation, damaging boards and components. For example, components used for aerospace electronics must be able to withstand temperatures that range from very cold (as low as minus 184° F in the thermosphere) to severely hot (approximately 5,792° F during a rocket launch). When selecting these components, especially when a COTS solution is implemented, thermal sensitivity must be a major concern.
#4 Components Vulnerable to Power Surges
Excessive heat on circuit boards can cause several failure mode issues. These include structural fatigue and spikes in the current flow. The latter can also be due to power supply surges or, in the case of high voltage PCBAs used in industrial applications, arcing. Irrespective of the source, large currents can wreak havoc on boards and destroy vulnerable unprotected components.
#5 Components Vulnerable to Radiation
For most PCBA development, radiation concerns are limited to minimizing EMI or trying to attain electromagnetic compatibility with its environment. This is not insignificant as excessive noise can degrade signal integrity to the point where reliable TX/RX is not possible. For boards deployed aboard space vehicles where failure is not an option, radiation effects on electronic devices can cause significant damage.
#6 Components Vulnerable to Mechanical Strain
PCBAs that are deployed in aerospace systems, industrial machinery and automobiles face mechanical challenges. These include shock and vibration that can crack and break boards and sever component solder joints and pins.
#7 End-of-Life Components
Electronic components, like all manufactured systems, have a finite operational lifetime. Continuing to use components beyond this point significantly increases the probability of failure due to mechanical fatigue. There is a component lifecycle during which the availability of the component goes through various stages of availability. The end of this cycle is obsolescence where the component is no longer produced. Components sourced during this end-of-life (EOL) stage are typically outdated and may not meet newer performance requirements, which makes them subject to premature failure, as well.
#8 Counterfeit Components
Although there are standards and regulations in place that specifically target counterfeit components, they still find their way onto many boards. You should make avoiding counterfeit components a priority as they are more likely to be made of lower quality materials and not meet the stated performance criteria on which your design is based. Therefore, the probability of failure can be high.
The Engineer's Guide to PCBA Manufacturing Complexity
How Can Electronic Component Failures Be Avoided?
As explained above, component failures are possible and in some cases even probable. By committing to habits that focus on mitigating the potential causes of electronic component failure, you can increase the likelihood that your boards and components will perform as intended over their operational lifetimes.
Habits for Avoiding Electronic Component Failures
- Utilize conformal coating.
Information on conformal coating standards.
- Apply moisture protection methods.
Information on the best PCBA moisture protection methods.
- Follow good handling and storage guidelines.
Information on the best storage guidelines to follow.
- Understand and apply good thermal dissipation and distribution techniques.
Information on thermal dissipation versus thermal distribution.
- Utilize protection circuitry.
Information on protecting against high currents.
- Apply radiation hardening techniques, if necessary.
Information on radiation hardening for electronics.
- Ensure the structural integrity of board construction.
Information on ensuring PCBA structural integrity.
- Ensure your component procurement process is secure.
Information on de-risking your component procurement process.
Avoiding component failure is not limited to selection during design. Instead, it requires a partnership with your CM to effectively institute the guidelines listed. At Tempo Automation, the PCB industry leader for high-quality fast circuit board prototyping and low volume production, quality control is woven into all aspects of our operations.
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This commitment ensures that your boards are reliably built to the highest manufacturing standards, which is essential to avoid failure once installed.
And to help you get started on the best path, we furnish information for your DFM checks and enable you to easily view and download DRC files. If you’re an Altium Designer or Cadence Allegro user, you can simply add these files to your PCB design software. For Mentor Pads or other design packages, we furnish DRC information in other CAD formats and Excel.
If you are ready to have your design manufactured, try our quote tool to upload your CAD and BOM files. If you want more information on the most common electronic components that fail and how to avoid them, contact us.