Dippable PCB coatings

[Imagewerx]

I have (or will soon have) a number of PCBs that I want to cover with some sort of coating.According to specs all the components on the board are suitable for this type of treatment.

The boards are small (ish) at 90 X 40mm and will have half a dozen or so wires at one end.
The coating will be partly for protection,but also to hide component values from prying eyes.
It needs to be easy to apply,so dippable and preferably air drying rather than two pack that needs a hardener to be mixed with it.
A hard sort of ceramic fnish would be ideal if possible,colour not really important.

I know what's available so I'm really more interested in what people have actually used and meets my criteria,and also is available in the UK and isn't too expensive.

Chris.

 

[Triode]

I'm curious about this too, I've only recently gotten started making my own PCBs. There may also be spray or brush on protective coatings that would work.

 

[cobra1]

i use liquid rubber or epoxy resin

 

[ikalogic]

eopxy resin for me. it also protects the board. be aware some resins are not compatible with this kind of applications as they contain some metals in it and is somehow conductive.

 

[Imagewerx]

Thanks for the annswers so far,but the reason I don't want epoxy resin or similar two pack or two part coating is I really want air drying as stated in the first post.Rubber would be too soft and could be peeled off,hence the need for a hard finish to the coating.

Chris.

 

[cr0sh]

I wonder if something like the stuff used for porcelain repair (like on sinks and tubs) would work? I'm not sure how non-conductive they are, but they do harden to something like a ceramic finish, air dry, you could possibly dip the boards in such a liquid (though I've only seen it sprayed on when used for tubs and sinks).

 

[canadaelk]

Are you trying to protect your "invention" or protect the circuit from harsh invironment? E

 

[Imagewerx]

I wonder if something like the stuff used for porcelain repair (like on sinks and tubs) would work? I'm not sure how non-conductive they are, but they do harden to something like a ceramic finish, air dry, you could possibly dip the boards in such a liquid (though I've only seen it sprayed on when used for tubs and sinks).

Thanks,good idea and certainly worth looking into.

Are you trying to protect your "invention" or protect the circuit from harsh invironment? E

Both,but more the first one.

Chris.

 

[Boncuk]

Try "Plastik70" made by "Kontakt-Chemie".

Two coats of the spray cover not only the copper traces but also the solder.

Boncuk

 

[bigal_scorpio]

Hi mate,

A lot of companies used to simply sand off the IC markings!

Its very hard to identify an IC or transistor just by their shape.

Edit. You could then rubber dip as advised and imagine their dissappointment when they manage to peel off the rubber or silicon. hehehe

Al

 

[Imagewerx]

Try "Plastik70" made by "Kontakt-Chemie".

Two coats of the spray cover not only the copper traces but also the solder.

Boncuk

Thanks for that,but it doesn't realy cover thickly enough for what I need,also being in an aerosol it'd be way too expensive.

Hi mate,

A lot of companies used to simply sand off the IC markings!

Its very hard to identify an IC or transistor just by their shape.

Edit. You could then rubber dip as advised and imagine their dissappointment when they manage to peel off the rubber or silicon. hehehe

Al

I have seen that quite a lot,but I need to hide the board layout as well,sanding that off probably wouldn't be a very good idea.
Looking like good old fashioned resin potting might be the most cost effective answer,just need to get a good deal on some potting boxes now.

Chris.

 

[indulis]

Search for "conformal coating"

 

[DirtyLude]

Looks like you are looking more for a 'potting compound' rather than a conformal coating. If you search digikey, you'll see loads of them. You might be able to dip these, but they are usually just used to fill an enclosure with everything inside it.

 

[Imagewerx]

If conformal coatings are still no more than clear lacquer,then that's the opposite to what I'm looking for.

Still on the lookout for something dippable,but it's looking more likely to be old fashioned plastic boxes and potting resin.

Chris.