Five ways to mitigate PCB component availability problems
The electronics design world is by now aware that there is a very serious components shortage. Allocation and shortages hit every few years, but this one seems to be the worst in recent memory, the hardest hit seem to be ceramic capacitors, but other passives as well as a variety of connectors and silicon parts are also caught up in the shortage storm.
By Duane Benson, Chief Technology Champion at Screaming Circuits
This shortage could be a problem until 2020 and the supply chain and world of components manufactures will likely be a different animal coming out of it.
This isn't that just a problem for high volume producers, it affects anyone regardless of volume and though what you can do about it may differ, it has or soon will hit everyone. Here's five things you can do to minimise the effects, starting with the most important thing for people who need low volumes manufactured:
1. Check the availability of all of your parts immediately before sending your Bill of Materials (BOM)
It's not uncommon for a part to be in stock one day and out the next. There are cases where the part is in stock in the morning and out by the afternoon. In order to quote and order your parts, verify that they are in stock as the last thing you do before sending your files to your PCB assembler.
At the moment, almost every BOM has one or more parts that are out of stock. At Screaming Circuits, you will be sent an email about the parts being out of stock. Nothing further can be done until you respond, building cannot start without parts and substitutions can’t be guessed at. A last minute check can save days of delay.
2. Put one or two alternate part numbers in your BOM, especially for passives.
PCB assemblers don't know your project, so can't pick a sub for you. Give some alternates and put them on the same line as the original part, slightly to the right. And be sure to give any special instructions if you've put alternates in the BOM.
3. Consider your parts values carefully. You may be able to pick something with better availability.
The 0.01uF capacitor is the hardest hit component. It's the most commonly used bypass capacitor. Some designs need exactly that value, but many don't. It may be easier to find a 0.022uF, a 0.0047uF, or something else close enough. If that's the case, choose a close enough value that has better supply, or put one in as an alternate.
4. You might need a slight redesign to use a smaller package.
Since smaller packages can be used in more applications, many suppliers will be allocating more of their foundry capacity to smaller form factors like 0402 and 0201 sizes. Some component manufacturers have said they'll be permanently discontinuing anything bigger than 0402 parts except when absolutely necessary.
Stick with 0402 size passives. It may be easier to find the parts you need in that package, and those size parts will be the first ones to come back in stock.
5. If you receive a message about an unavailable part, respond as quickly as possible.
Assemblers try to avoid any delays in this process, but can only do so much. Help out by responding as soon as possible, and don't be afraid to give more than one part number to try to prevent further delays to assembly.