Conformal coatings

[Bowley]

Anyone using conformal coatings on power distribution boards?
Any recommendations?

Cheers

Steve

 

[PeterLester]

Conformal clear coating is available from most electronics stores for the purpose of providing a protective sealing layer against moisture, chemicals, dust etc. This is an essential protective barrier for products sold into industrial and oil and gas sectors where protection is needed against H2S in the air. H2S eats copper traces rapidly. This clear coating is available from many electronics specialty stores but if not applied by the board manufacturer before sale, may void the warrany on the basis of:
a) Reduced PCB heat dissipation (shortens board life)
b) renders board component replacement/repair impossible.

But once you are past warranty, it could extend board life by eliminating contaminants as mentioned previously.

 

[DucktileMedia]

how different is that from liquid electrical tape? I have certainly thought about slathering some of my boards in that stuff.

 

[Breezemont]

http://www.neverwet.com/

This looks pretty good. Can't find it for sale though.

 

[Andy Johnson-Laird]

Rather Good Guide to Spraying MK Boards.

This may be helpful to those who have MK boards.

Andy.

 

[parkyi]

RS Components have a good range of Conformal coatings.

I've used the Electrolube Acrylic stuff before on boards at work, very good stuff.

http://uk.rs-online.com/web/c/?sra=oss&r=t&searchTerm=conformal+coating&x=0&y=0

Parky

 

[PeterLester]

Don't investigate the neverwet.com site..... as indicated in the 10-05-2012 postings here..... it has been identified by AV software as a spam threat. Also IMHO any product such as this or scotchguard is intended for fabric and not to protect electronic components. Some are also penetrants that can enter discrete components and change internal electrical characteristics, e.g. capacitors. The use of liquid electrical tape is probably not such a good idea either unless it is clear. It is important to work with a coating that remains clear after the application.

 

[bsdave]

Humiseal make some of the best on the market 1A33 is a type UR (Urethane) and 1B31 is a type AR (Acrylic). Both are good a keeping out moisture. 1A33 is good at keeping out most solvants, 1B31 is not and will soften with solvant contact. Dust will stick to the 1B31.

 

[nicko777]

Whilst in the RAAF I worked in Micro Miniature Repairs on the FA-18 Hornets where we did multilayer board repairs, multi-pin IC replacement, plating and conformal coating. From memory it was a urethane product but it had UV visible content so that I could see where the coating was missing using a UV light. This was ideal for dabbing a bit more on or ensuring I have removed it to repair or desolder. Maybe depending upon which conformal coating you use, it is not necessarily impossible to remove, certainly not in my case when using a solvent to remove it. I have found a few on alibaba that seem to be suitable. Check the temperature rating too.

I don't have an RC as yet but I have thought of weather issues and thus will use conformal coating where possible when I do get an RC

 

[gtranquilla]

I use MG Chemicals Urethane type conformal coating for electronic projects...... protects electronics from H2S and conductive dusts such as carbon fiber especially when moisture us present. There is an extensive article on on this forum how to apply it correctly to printed circuit boards without covering bare connectors etc. especially for the the MikroKopter..... not much of an issue for housed electronics..... and IMHO, best suited for components that are MIL spec...... some solvents can do significant damage to capacitors etc. especially if not MIL spec.
Coatings are clear such that UV light source etc. should not be necessary.

 

[nicko777]

I don't concur, the problem with clear you often can't see the coating conformity, thus an inexpensive UV light with the suggested coating will gaurantee you won't put it where you don't want to and or put it where it needs it, especially after replacing components. I have never heard of any component being affected by a solvent, but then again I am not sure what I used and then again being in the RAAF everything was MIL spec It is a case of asking the manufacturer of the solvent if it affects components..... one day maybe I will....