For some reason, there always seemed to be a large dray of squirrels around our house growing up. They could be entertaining when they were scurrying about. But, they could also be a nuisance when they got into the attic. I think they were around because of a big pecan tree that we had in the backyard. I loved that tree, as well, because it provided the nuts that my Mom used for her pecan pie. Now, I could be a bit biased, but I have never tasted anything that could even come close to my Mom’s. And I would travel any distance for a slice, as I did for many holidays over the years.
An Irreplaceable Dish
Similarly, when producing a new PCBA design it can seem as though there is only one component that will do. There can be many reasons for this opinion. Perhaps, you have used it before and it worked perfectly or it employs some new technology that you cannot wait to try. Whatever the reason, these exotic or unique components sometimes can be hard to resist. However, there can be pitfalls; such as counterfeits and obsolescence that you should weigh before settling on an exotic component. Let’s further define exotic components and their uses and when you should or maybe not use them.
What Are Exotic Electronic Components?
We can define exotic electronic components as those circuit elements that are hard to find. Typically, these components are hard to find because they are rarely used, have unique functionality or can only be obtained from limited sources. To some degree, most components can be considered exotic at some point during their lifecycle, as shown below.
Component availability over time
As shown in the graph above, when a component is initially introduced it will typically be limited in its distribution and/or sources where it can be obtained. The same is true as the lifecycle comes to an end. Lack of availability at other times is usually due to a component shortage. Irrespective of the underlying cause there are common reasons when these electronic components should be used and when they should be avoided.
When to Use and When Not to Use Exotic Components
Before discussing when to use exotic components, let’s take a look at why including these components in your design may not be such a good idea. Just as with other aspects of PCBA design, component selection should be optimized. It goes without saying that the component must meet your functionality requirements; however, there are other considerations. These include manufacturing and production concerns, as listed below.
Reasons not to use an Exotic Component:
- Are you unable to verify the source of the component?
If you are designing a board for critical industries; such as aerospace, medical devices or the military, a secure supply chain is a primary concern that requires you to take steps to avoid counterfeit components; such as being able to trace components back to the source.
- Are sufficient numbers unavailable for planned production?
If there is any reason to doubt that adequate supply will be available for the foreseeable future, it is probably best that you opt for an alternative component.
There may be times, however rare, when you feel that you must go with an exotic component. Some of these are listed below.
Reasons to use an Exotic Component
- Does the client or customer request it to be used?
At times, a specific component may be requested due to familiarity or for some other reason. In these cases, substitution may not be an option.
- Does it possess the capability or functionality specifically needed for the application?
Another reason for going with an exotic component is if it has capability or functionality that is not available in another component. As an example, there are specialized mission-critical components for aerospace and military applications that do not have comparable alternatives due to special processing and high development costs.
In these cases, you should understand that there are risks involved. Therefore, you should approach the decision as a risk management proposition. That includes monitoring component availability and setting up controls in the case of a contingency, such as shortfall.
|Tempo‘s Custom PCB Manufacturing Service|
Tempo Automation is the leader in building high-quality complex boards, fast. Not only do we manufacture your prototypes or low-volume production PCBAs, but we source components from the most reputable sources with secure supply chains. However, if you can opt to use exotic components that you supply, as well and they will be assembled to the same high standards.
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 electronic components and their uses, including exotics, contact us.