Remove IC part number

[madhu.wesly01]

Hello,

Can anyone suggest me the easy way to remove the IC part number ? (other than sand paper)

Thanks in advance

[Nusa]

For prototypes and small runs, that pretty much is the best way. An abrasive bit on a dremel tool works pretty well.

For automated production, a marking laser can be used to burn off the markings. Another alternative is to cover the markings with epoxy ink.

If the goal is to stop determined reverse-engineers, it won't work. It'll only slow down the casual copy-cats.

[KL27x]

Dremel tool and round nose carbide bur. Like an engraving tool on steroids. Diamond burr not bad either. Maybe even better if you're talking micro thin QFN and whatnot. If it has to look better, Proxxon makes a pen sander that looks like it was made for this. I'm assuming you can't easily sand the parts until after assembly for logistics and cost and well, it would be really hard to sand tiny IC's that are loose.

I love Harbor Freight, but I've no luck with cheap rotary tools. They tend to have bad run-out, which is fine for cutoff discs, but not for this. Adjustable speed Dremel or Proxxon/Micromot. This is just about the only tool I'm a brand whore. It doesn't matter how many 5 star ratings a generic rotary tool has; these reviewers just don't know what a <2 mil runout vs >10 mil runout means when it comes to something like this. If you've a lot to do, the money on a good rotary tool will pay for itself.

Drills, also. For some reason, the cheapest HF die grinders and routers and drill presses run close to perfectly true. But the cheap hand drills (even Ryobi and BD) and rotary tools I have ever bought have always had runout in the teens or even worse. For hand drills that rarely matters too much, though.

[Ysjoelfir]

Why don't you just leave it on there? I see no use in grinding it off, it just pisses everyone off who needs to work with it in the future.

[KaneTW]

Security by obscurity is a minor hindrance at best, and the only one you'll actually annoy is people trying to repair your device.

[station240]

If you only want to stop the Chinese Factories that copy anything that seems popular, often at the request of a client who wants a cheaper version
Then sanding the marking off the chip would stop most of them.

Wouldn't stop anyone who actually reverse engineers things, as they would acid etch the silicon wafer out of the IC, or figure out the device from what pins have VCC, ground, crystal osc etc.
If you really want to screw with them, put a wrong part number next to the IC you sanded the top off.

[b_force]

Why don't you just leave it on there? I see no use in grinding it off, it just pisses everyone off who needs to work with it in the future.

Exactly this.
In pretty much any case people can backward engineer the circuit anyway.
In worst case they just simply even decap the chip or use a x-ray to see what's going on.

[KL27x]

^I'd rather give them the worst case. You don't know what industry the OP is in. Days of being ahead might be huge money.

Or it might be small enough where decapping and Xray stuff is a relatively big deterrent.

Or his boss might have tasked him with obscuring the part numbers, and he's starting to get arthritis. 

[amyk]

It's pretty easy to figure out unless you use an ASIC, in which case knowing the part number is not going to be much use anyway.

That said, someone needs to make a "search by pinout" website, just like the SMD identifier ones. I have something I use locally but it's far from complete.

[ebclr]

It's a bad idea, just show how week you are,  you can sand, laser but the ic always will be there to be decaped, and any serious reverse engineer will easily know your 'magic is'. You will lose long-term maintenance, and  some customers to do this ridiculous practice. In resume don't do that

[grifftech]

DON'T

[IDEngineer]

I love Harbor Freight, but I've no luck with cheap rotary tools. They tend to have bad run-out, which is fine for cutoff discs, but not for this.

Try a Dremel-sized wire wheel. It's forgiving of runout while still doing the job.

I agree in general... "security by obscurity" really isn't security at all. But if you must remove it using a cheap tool with questionable runout, a wire wheel is the answer.

[james_s]

It's a waste of time. Whenever I see an IC with the number sanded off I am that much more interested in figuring out what it is, which is rarely difficult. I have reverse engineered stuff simply because some idiot thought sanding the number off the IC would stop me, when I otherwise wouldn't have bothered. It's a fool's errand.

[IDEngineer]

He may be stuck complying with someone else's requirement. A close friend owns and operates a midsized Contract Manufacturing facility and some of the specs he has to follow are really good for a laugh. A recent knee-slapper was that metal contacts, which were made of aluminum, had to be stored in antistatic bags for protection against ESD. But that's what the customer requires, so he's happy to charge them for it.

[james_s]

That's amusing, sounds like the kind of rules you get when politicians try to regulate technology.

Some manager probably decided to implement a rule that all electronic components need to be stored in ESD safe packaging, and the metal contacts count as electronic components. I suppose there is *some* validity to the rule in that it avoids having to decide on a case by case basis what parts need the protection, but specifying all silicon or something of that nature would have had less ridiculous results.

[mojoe]

I agree with the "Don't" crowd.

The first time I came across a sanded chip was many years ago. I had a TRS-80 Model III (before the IBM PC). Someone sold an Atari joystick that connected to the TRS-80 via the expansion slot. It was a bit pricey, but I bought one, because it worked with many of the TRS-80 games of the day. When I received it, I found the joystick wired to a tiny PCB that contained a card edge connector and one IC (with the number sanded off).

Because of the high price, the missing chip number pissed me off enough that I figured out what it was (a 7400, quad nand gate). Goes to prove what someone else said. Missing chip numbers make the customer unhappy, and some will take it as a challenge.

[coppercone2]

the only way to fight those people is with tarrifs

[LukeB]

You know, a bit of flux on a small IC seems to obscure the markings beyond what my eyes can see. It seems to soak in and do something. I may just be puffing smoke?? but it just a frustration i have had with tiny ics and flux.

[mikeselectricstuff]

Removing chip numbers just makes you look like an amateur, or someone who ripped off a design and is too stupid to realise that there are people out there cleverer then them who can figure it out.

[Zero999]

Removing chip numbers just makes you look like an amateur, or someone who ripped off a design and is too stupid to realise that there are people out there cleverer then them who can figure it out.

Yes, if simply providing the part number would make it a lot easier to reverse engineer, then your circuit isn't that innovative or special in the first place. It's quite likely someone with a reasonable amount of experience could simply guess what parts are used and redesign it it, just by knowing what the circuit does. Heck, they might even make some improvements to your design!