Screaming Circuits: Embedded Passives


I recently participated in the Altium pod cast where I discussed the origins of Screaming Circuits, some DFM hints and a few other topics. I was discussing some of the challenges everyone is having these days in procuring components and Judy Warner, the host of the podcast asked if we see many people using embedded passives as a way to mitigate supply difficulties.

I told her that I don’t think we’ve seen very many embedded passives come through our shop; too late realizing that given that embedded passives are – embedded – inside – the PC board, we wouldn’t actually see them.

Then, somewhat coincidentally, yesterday I was visiting our San Diego PCB Design division and that very subject came up. It seems that our SDPCB layout group does sometimes use embedded passives in some of the boards they layout. I need to have a conversation with them about the layout and fab implications of embedding passives.

I’m kind of guessing here at what they look like, so don’t that this representation as fact.

Originally embedded passives were invented primarily for space savings. Now with 0201 and 01005 components available, that’s less of a need these days, but embeddeds can still be advantageous for reduction of parasitic effects or in areas where even 01005s are impractical, like termination of large numbers of transmission lines.

What I’m wondering, is if embedded passives could be a viable solution to some of the supply chain issues we’re seeing lately? If you need a few dozen 0.01 uF bypass capacitors on your PCB, but can’t find them*, would embedded capacitors be a practical solution?

*It’s important to note, that in most cases, the term “embedded passives” refers to the process of using various resistive and dielectric materials to create the components within the layers of the PCBs. I’m not talking about embedding the currently hard to find discrete resistor and capacitors within the PCB fab.

Duane Benson
Sorry. I have nothing snarky to say, and as you know, if you don’t have anything snarky to say, you shouldn’t say anything.



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