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What epoxy used for encapsulating pcb?

Rleo6965

Jan 22, 2012
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Saw a picture of encapsule pcb board in another thread.



I want also to encapsule secret circuit on a small pcb to protect my design so that it can not be easily copied. It's about 2"X2 1/2" pcb. Can somebody give me the name of brand of this kind of epoxy. Thanks in advance.

It's the circuit for my Multiple Spark CDIS already passed 3 months of actual test in my car.. Planning to mass produce and sell it here in Philippines.:)
 

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john monks

Mar 9, 2012
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Conformal coating is a clear liquid that helps make circuit boards more resistant to water. It is applied by dipping the circuit board into the substance after the board is loaded. There are many different venders for potting and encapsulating epoxy on the Internet. MgChemicals is one. But just for information, when I come across a damaged pc board or have to drill out a short, I typically fill the hole with ordinary 2-Ton epoxy.
 

Rleo6965

Jan 22, 2012
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My purpose was to hide component on pcb , mechanically hard to removed conformal coating, no corrosive chemical properties and can withstand at least 600V. So it must not "clear epoxy" and can't be easily removed using hot air tool.

I took me 6 months to developed the cdis circuits and I don't want it to be easily copied or reverse engineer.
 

CocaCola

Apr 7, 2012
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Fact is nothing is all that hard to remove, just look at some of the forums where people do it to see what is inside... I have see people grind away epoxy with wire brushes layer by layer with a dremel tool, or use a heat gun and dental picks, and others that can't be bothered with slow labor, and don't mind the safety issues just jump right into the good ol' fuming nitric acid that eats away epoxy painlessly even on commercial IC chips... Trust me a few bucks to purchase the fuming nitric acid is well within the means of anyone that desires to see what makes it tick inside... You are just basically keeping the honest, honest, not actually stopping or hindering those that want to crack it...

Yes, over the counter 2 part epoxies will fail under heat a lot easier then commercial solutions, but many of the commercial solutions require precise baking profiles and/or uv exposure profiles... I have looked at a few commercial solutions myself and found most of them out of my $$$ range or too complicated (impractical) for the DIY user...

What I have found best, is to get some HIGH quality UV cure or 2k epoxy paint (they sell it for sign making as well as RC planes where the 'nitro' fuel dissolves just about any other paint) Get this in black, or deep green and give the board a nice once or twice over... Then you can use even a translucent or solid over the counter potting epoxy, as being opaque isn't all that important once you camouflage it underneath with the paint... You can even just tint clear with some black pigment (easily obtained from any fiberglass gelcoat company) and get it plenty opaque as to not be able to identify what is inside... Wanna get real fancy, now that the circuit is pre-coated with the epoxy paint (aka no risk of shorts) as I suggest, mix in some hobby glitter to your potting epoxy that you pour over it, to really make it pretty, and impossible to see through...
 
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john monks

Mar 9, 2012
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I understand your needs completely. MgChemicals is one. There are many others on the net.
 

Rleo6965

Jan 22, 2012
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It seems MG Chemicals 832B Black Encapsulating product suits my requirement. Already request quotation in Mouser Singapore. Next problem to solve was the Aluminum Die Cast Casing. It's very expensive if bought internationally. It seems I have to look for local Aluminum fabricator. Hope I can DIY the casing. :D

Thank you for the help.
Roger
 
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