conformal coating or alternatives for PCB?

Thread Starter

DJ_AA

Joined Aug 6, 2021
308
Hi All

I aim to place some PCB in the outdoors in a IP rated enclosure, these are sensors circuit with some passive components that could be effected by humidity or temperature change. To avoid this issue I am thinking about using conformal coating, the type you get in spray can.

Can anyone advice on the right conformal coating and if the spray can solution in terms applying it during small scale production is a good option?

Thanks
 

LowQCab

Joined Nov 6, 2012
4,187
"Potting" is probably the safest way to go.

Do You have several pictures of your Project that You could post ?
A Schematic would also be a bonus.
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ericgibbs

Joined Jan 29, 2010
18,984
PCB in the outdoors in a IP rated enclosure,
Hi DJ,
What is the IP rating of the enclosure?
A conformal coating will not give any protection against component temperature changes, it can also increase the self heating of 'sensitive' components due to restricting heat dissipation.

If you use a conformal coating, use a type that will allow easy failed component replacement and re-coating.

You state: these are sensors circuits

As requested, a posted circuit and a photo of the PCB mounted in its enclosure would be helpful.
E
 

Thread Starter

DJ_AA

Joined Aug 6, 2021
308
The PCB is not yet designed, as I am doing a little planning.

What's I am worried about a build up of condensation on a capacitor or resistor and effect my overall performance.

Enclosure will be IP 67, but there will be some exposed outlets facing downward to let in air flow my the sensors.
 

MisterBill2

Joined Jan 23, 2018
18,928
Two kinds of coatings I am familiar with, one is a soft coating that will protect the components and board from conductive contamination, but it is easy to cut off for part replacement.
The other kinds are either slightly flexible and mixed with sand, or a rock-hard material that forms a solid block, suitable for a very high vibration application, like on a 2-stroke race-bike engine, possibly.
I like the softer stuff for things that might need to be repaired eventually.
 

MaxHeadRoom

Joined Jul 18, 2013
28,758
There is the compound used in the electrical distribution industry called Duct-Seal, it is pliable, non-hardening and non stick.
I have used this on occasion.
 
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