Electronic Component Vulnerability Assessment in PCB Design
We all have our vulnerabilities. For the comic book hero Superman it is a fictional substance called “Kryptonite,” which will extinguish his strength. For me it’s Milk Duds, and everyone in my family knows that I can be bribed with a box. And then there are the more serious examples such as crops that are vulnerable to cold weather, or even your home being vulnerable to water damage.
Electronic components also have their vulnerabilities. If you aren’t aware of these, you could end up choosing the wrong component for your design. These components may fail prematurely, or give you intermittent results that can result in time consuming and costly efforts to debug and correct. The important thing is to make the correct choices up front so that you can avoid any problems due to electronic component vulnerability. Here are some ideas on how to do that.
Electronic Component Vulnerability Considerations
First of all let’s look at some of the vulnerabilities that electronic components have:
Temperature: Different components will have varied temperature limits on their components, and two different manufacturers may have different temperature limits on the same component. Because of this, you may have to choose between component vendors to pick the part that will not be vulnerable in the operating environment that you are designing.
Electrostatic Discharge (ESD): Some components are sensitive enough that they could be damaged by ESD. Although you can control this to some degree by your part selection, the real key is to make sure that your components are handled appropriately to prevent their contamination.
Moisture Sensitivity Level (MSL): Another vulnerability that components will have due to how they are handled is to moisture. If they are miss-handled during stocking or assembly, the absorbed moisture could expand with the heat of the assembly process causing damage to the part.
These problems can be resolved by choosing the parts that best fit the environment that your design will be operating in, as well as ensuring that proper handling is observed during assembly. But those aren’t the only vulnerabilities that components may be subjected to, the following list can be just as damaging to components:
Wrong Components: Sometimes a different component may be shipped then what is labeled, or the PCB assembler miss-handles the part so that it is loaded incorrectly into the assembly process. To guard against problems like these, it is best to work with high quality PCB manufacturers with precise QA and assembly processes.
Counterfeit Components: Sometimes non-compliant components are used from questionable sources due to the regular components no longer being available. To protect yourself from this vulnerability make sure to work with manufacturers that have solid industry contacts with reputable component vendors and suppliers so that you get the high quality components that you were expecting.
Incorrect PCB Component Footprints: Your board may be built with the best components, but if the PCB land patterns and footprints are incorrect you are still going to have problems. The components may not solder correctly to the board leaving them vulnerable to broken solder joints over time. To avoid this, make sure that the PCB library parts that are used on your design are correct for the components that they will host.
There’s a lot to consider when selecting electronic components
PCB Problems Due to Component Vulnerability
The components used on your board should work as expected, and when they don’t your board will end up having problems. You could see intermittent failures that are difficult to find and correct, or you could have outright failures that require repair or even scrapping the board. Here are some of the problems that your board may experience due to component vulnerability problems:
Circuit Failures due to Incorrect Parts: This may seem like a very basic thing, but using the wrong part for the circuit is going to cause problems in how the board operates. Protect yourself by using your circuit simulation tools to confirm your parts before you finish the design. You will save a lot of debug time and re-spins of prototype builds if you do.
Manufacturability Problems: If the parts are placed on the board incorrectly, you could end up with manufacturing problems. These can often cause PCB assembly delays and additional costs, and they could also lead to un-detected soldering problems that could result in unexpected component failures. By following proper design for manufacturability (DFM) rules, your board will go through manufacturing cleanly.
Shortened Manufacturing Life Cycle: Circuit boards usually have a life cycle that they are designed for, where the boards will be built over time to service a product. When components are no longer available due to end of life (EOL) or obsolescence (OBS), the future builds of the board will be questionable putting the life cycle of the product in jeopardy. To avoid this, don’t use parts in the initial design that are known to be EOL or OBS. By working with a manufacturer that can help you with your component selection, you will be well prepared for the life span of the product.
Using the right tools can help you to avoid electronic component vulnerability risks
How to Mitigate Your Component Vulnerability Risks
One way that you can help yourself to avoid the risks associated with component vulnerability is to work with a manufacturer that can help you with your component selection. Usually these manufacturers have systems in place that alert them well in advance to parts that are no longer going to be available, as well as knowing which parts are the best choice for your design. A high quality contract manufacturer can help you to avoid many of the component vulnerability problems that we’ve discussed.
Another way to help yourself avoid component problems is to make sure that you are using the right parts for your design, and that you are selecting parts from reliable sources. In addition to schematic capture and PCB layout, you need circuit simulation, design analysis, and library tools to cover everything you need to design successfully. This requires a PCB design system that not only has all of this in one complete system, but also has the library resources available that you can access for quality parts.
The good news is that the PCB design tools that you are looking for is already available from the Cadence line of high performance EDA tools. OrCAD PCB Designer has the tools that we’ve discussed here such as schematic capture, PSpice circuit simulation, PCB layout, and high speed board design analysis.
If you’re looking to learn more about how Cadence has the solution for you, talk to us and our team of experts.