Lubricant for PCB's 1

[var10]

Hi,

We have a Printed circuit board which sits on an aluminium plate. The contact surface have some tracks but no components. So I am just wondering if there are any lubricants which will and can stop rubbing against these tracks? I thought of epoxy potting compound but could be a problem during repairs. Please let me know if there are any alternatives?

Thanks in advance!

V.

 

[KENAT]

Lubricants? Does it slide or something?

If you need some kind of thin insulator then look at conformal coatings or maybe tapes etc.

Kapton may be an obvious material to consider

http://en.wikipedia.org/wiki/Kapton.

If you need it super slidey then UHMWPE or PTFE tape or similar might be worth a look.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[ScottyUK]

Is the relative movement between the plate and the PCB intended or undesired? If the former it sounds like a design flaw, and if the latter can you prevent the relative movement completely? Or perhaps use a rubber or silicone sheet?

 

[mcgyvr]

I use "Formex GK" sheet for insulation in situations like that..
Well I would never design a PCB w/exposed traces that sit on aluminum.. That's just asking for a short if any of those traces are at a different potential.

 

[var10]

Kapton sounds to be a very promising option. The movement is very minimal though it is undesired.

 

[MikeHalloran]

Kapton is a horrible choice, because its decomposition products, from electrical stress and/or mechanical abrasion, are conductive.

e.g.:

http://www.falconwire.net/Web/Default.aspx

Even if you use insulation that doesn't break down, it's not hard to conjecture a situation where moisture wicked into the capillary gaps between insulation and traces will cause problems.

Move the damn traces off the damn faying surface.
... and yell at the designer who put them there.




Mike Halloran
Pembroke Pines, FL, USA

 

[TheTick]

Dielectric grease.

Also, there are some compounds made for ensuring thermal conduction between components and heat sinks. I recall the replacement electronic ignition module for my old El Camino came with a tube of such stuff.

 

[mcgyvr]

What is the reason the PCB is sitting on the aluminum plate in the first place?

insulating sheets, thermal gap pads, standoff hardware, etc... will all solve the problem as posted but I'd suspect there is an underlying reason the board was put there in the first place.
Any pcb designer/engineer should know that a soldermask should never be relied upon for insulation.

 

[MintJulep]

Circuit Board Standoffs