PCB Assembly Services - Screaming Circuits: Prepping for Supply Chain Issues - Alternate part numbers


Prepping for Supply Chain Issues - Alternate part numbers

So far, Screaming Circuits has seen little impact from the world-wide coronavirus outbreak. However, that may change as component manufacturer factory closures in the affected areas start to eat into the supply chain. Shortages could start to appear at any time. As usual, MLCCs and other passives will likely be the worst affected. Fortunately, passives tend to have the most alternatives available.

However, even if alternates are available, we can't just automatically and arbitrarily make substitutions. If we did so, it would likely be fine in some cases, but not in others. We don't know if any given part fits into the "close is close enough" or is in the "the whole system breaks down if this value ins't exact" category.

What then can we do? Well, we can think about substitutions (also called alternates) ahead of time.

Here's what happens when parts go out of stock quickly and we don't have a list of acceptable subs.

  1. You send us a BOM to quote or upload it to our online BOM quote
  2. We find that three out of 24 part numbers have gone out of stock between now and the time you originally looked them up
  3. Either we pick some alternate part numbers and send them to you for approval or we ask you for alternates
  4. You send us approval
  5. Now two different parts on the original BOM have gone out of stock and the cycle repeats


The best thing to do is to start including alternate part numbers in the first bill of materials that you send us. Put them on the same spreadsheet line, to the right of the primary part. You only need the manufacturer name and manufacturers part number. Take a look at the example below. I only put in a few subs, but if you can find them, go ahead and gives us a few for each BOM line item.

BOM subs

Stay tuned for more thoughts on how to be prepared for shortages before they become a problem.

Duane Benson
Think of this as time travel. Me from the future wants to chill instead of panicking about MLCCs again



Post a comment

If you have a TypeKey or TypePad account, please Sign In.

« Can you Combine Panelization Techniques? | Main | Prepping - Risk Mitigation »