Vibration-Isolating Foam for PCB - Page 1
Forum section: electronics / general

author: KarthiAru
author_rank: Newbie
timestamp: March 24, 2025, 06:03:41 am
content: Hi everyone,I'm searching for a soft, resilient foam to isolate a PCB with a sensitive IMU from high-frequency motor vibrations. I came across a specific foam (photo attached) used in a PCB in a drone and am looking for something similar. The thickness of the foam in the photo is between 5-6mm. The material is very soft, doesn’t permanently deform, and quickly returns to its original shape after compression. Has anyone worked with similar materials and can identify what this might be?Thanks in advance!

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: March 24, 2025, 06:36:12 am
content: Hello KarthiAru,It seems to be a kind of lowdensity polyurethaneanti-static foam.This resellerhas a wide range of products.Here's a productthat seems quite close.

author: Jeroen3
author_rank: Super Contributor
timestamp: March 24, 2025, 08:48:53 am
content: Looks like generic antistatic foam. Is it slightly conductive?Maybe you can also use emc gaskets?https://www.we-online.com/en/components/products/WE-LT

author: Siwastaja
author_rank: Super Contributor
timestamp: March 24, 2025, 10:18:27 am
content: I once looked into vibration damping materials for IMUs and what I found out the subject is huge enough to warrant a few PhDs and whole R&D teams dedicated to just finding and qualifying the materials. The problem is like with any LC filters, some of the vibration will pass through anyway and now you have added resonances to frequencies which used to be OK before the addition of the filter: think about how, after an impulse, the IMU board will shuffle back and forth in this soft material, and think about non-linear spring forces in the material which cause it to shuffle in directions not related to that impulse! This cure can be 100 times worse than the original illness.You should start testing with hard coupling to first see if you have any problem, or if the vibration is something the IMU can reject (i.e., average it out - works as long as it does not cause non-linearities within the IMU). When I visited the Murata factory where some of the higher end IMU chips are made they showed/told us how they arranged a suspended/damped production line (basically on huge springs and shock absorbers), and finally chose to just bypass that with hard connection to the bedrock.Then again if you really do need the material, then... sorry for this non-answer but I wanted to say, good luck!

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 24, 2025, 01:50:31 pm
content: Sorbothane?

author: Kasper
author_rank: Frequent Contributor
timestamp: March 24, 2025, 03:44:21 pm
content: Probably heavier than your application but Quad Lock might give you some ideas.https://youtu.be/RqxARvggo24If you want to damp frequencies in the audio range, acoustic foam or caulk might work. Have not tried that myself.

author: GLouie
author_rank: Regular Contributor
timestamp: March 24, 2025, 06:57:43 pm
content: I think foam is a bad idea if you expect the device to last more than a few years. Virtually all foam degrades, some very quickly, changing characteristics and eventually turning to goo or dust. The time seems unpredictable. I suspect foam chemists know how to spec longer life.Adhesives have similar problems.