PCB Encapsulants to Annoy Copy Pirates

Araldaite 2014- grey epoxy. I use it, very, very good stuff !

Neato..

'Highmark Manufacturing uses Araldite in the manufacture of advanced ballistic protection body armor'

While on wiki. I came across this tidbit...

'Vinegar is an effective and safe solvent to clean up tools, brushes, skin, and most surfaces contaminated with epoxy resin or hardener.'

Huh..didn't know that..

When you try something let us(me) know how it goes?

Take a Dremel with a round rubber drum sanding attachment of about 1/2" diameter.

Grind off all the ID marks on the chips.

Then, pot it in "Stycast".

No, epoxy is what you need. Most anything else can be removed one way or another too easily.

There are high adhesion polyurethane potting compounds, but they are far more costly.

An alternative to fully potting it, would be to do the chip grind thing, and then 'paint' the epoxy over those chip-top locations. You could also 'paint' over the traces until the build up is high enough to hide them, but they can be traced via continuity tests usually.

You could also build a small trace array that you selectively cut and bridge to complete uniquely "keyed" circuits ala Dongle Key technology.

You could make each circuit unique, yet the same, yet harder to copy.

The disadvantages of potting generally far outweigh the likelihood that someone will copy your design. And if they're determined, they will anyhow.

John

Patent it. Thats what everybody else does.

What did you invent a time machine ?

It'll be awhile.. I just started the pcb design. Might be potting in Jan 2010.

D from BC Amateur smps designer British Columbia, Canada Posted to sci.electronics.design

I might try a solvent to smudge the ID on the IC.

In addition to adhesion, the potting has to resist solvent/chemical baths that pirates may use.

Maybe I could do some micro wire jumpers running through the epoxy. If tools are used to remove the epoxy, the pirates might buzz through the wires by accident.

Potting will make me feel good? :)

This might be ironic. It's possible the first people to tear into the epoxy potting will not be Asian copy cats but instead US patent owners who suspect their patent is being used without permission.

Hmm... I wonder if you can be made to reveal your design schematics/software/etc. if a patent holder is able to convince a judge that there's a very good change you're infringing on their patent, yet you have made it effectively impossible for an outside party to determine as much?

Not after you've actually done it a few times.

Is it?

John

A possibly unique smps controller.

Make a nice aluminum housing for it and put it together with left handed screws.

You can get chips marked with your company part number if you order enough. Make your part number for a 74HC04 be LM324 and etc.

Make it all "firmware" in a FPGA and use a coin cell battery to keep the FPGA always powered on. If they open it up poof goes the code.

2"

way

g,

so

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Could you also throw 'em a curveball by re-printing bogus ID's on the chips?

Something within the limits of credulity... I'm not suggesting you paint "555" on the top of a TMS340 or anything like that...

If you chose your part numbers carefully, you might send them on a wild goose chase... :)

Many these days are laser burned.

The Dremel grind will not hurt them.

The stuff I am thinking of is a tough rubbery thing that can stop a knife point or a bullet, much less most solvents that you worry about that would melt polycarbonate, but not this. It is used by NASA. It is the ONLY encapsulant they have approved for HV space applications.

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Of course. Why not? You would have to make the removed ID surface appear acceptable or authentic before applying the new info.

Anything different would at least cause lost time, and time is everything to copy cats.

Well, a good diagnostician could do a pretty good job of determining what something "must be" by basic examination and probing.

That would require it be visible, or accessible to probing.

Planned obsolescence, too. Good idea!

D: what about x-rays? Do they make lead oxide-filled epoxy? It's pretty trivial to x-ray through potting otherwise. ;-)

Tim

True.. I do try to dodge making plastic dust when I can. I don't like cleaning.

I might even try melting the number with an old soldering tip.

Dremel is probably the low cancer solution. Solvents make fumes and same goes for plastic melting.

D from BC Amateur smps designer British Columbia, Canada Posted to sci.electronics.design