erase label on an IC

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hi,
How to erase the label written on an atmega ?
Does Alcool or Aceton works ?
Thanks,
Olivier

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Try nitric acid to erase it for sure :D

Warning: Grumpy Old Chuff. Reading this post may severely damage your mental health.

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Use fine sand paper

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In case you didn't get it: MBedder was joking. Unless you want to risk ruining the chip, don't go for the acid.

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No, I'm absolutely serious.

In 1990's the smart Russian people making the homebrew Sinclairs have been widely using this technique to convert the cheap and available plasic DIP packaged 2716 OTP EPROM chips to the UV erasable EPROM - just carefully applying the smal nitric acid microdrops over the chip area until a hole reaches a light grey soft compound protecting the chip. Then the compound could be carefully removed and the chip could be exposed to UV, erased and reused for many times.

Warning: Grumpy Old Chuff. Reading this post may severely damage your mental health.

Last Edited: Tue. Nov 9, 2010 - 10:45 AM
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Yes, I got that :D
So no solvent can be used to erase a label, only sanding ?

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The label is laser engraved into the epoxy - have a look at it with a magnifying glass. If you want to stop people identifying your chip, then don't waste your time. The power pins are the first hint and if someone is REALLY serious, they'll just remove the package, read the chip ID and read the data out of it.

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Just to illustrate the nitric acid technology - ATMega128 chip revealed:

Warning: Grumpy Old Chuff. Reading this post may severely damage your mental health.

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Laser, sandblasting or sand paper.

Stealing Proteus doesn't make you an engineer.

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As mentioned, obscuring the label of a production chip will only discourage the lookie-loos, not any serious "attack".

I wouldn't dismiss some wiping with the nitric acid. Cheap enough to try if you are careful.

Even a quick look for reverse-engineering can usually identify the chip as "a micro or other similar central unit". For the popular brands I'd think a bit of signal tracking along with the packaging would identify UARTs, SPI, ADC, as well as power and ground pins. Then, how many popular micros match? Probably not a lot.

Once identified as an AVR, are you also then going to destroy all of the possible entry points for a Read Signature? If not, the model is readily identified.

Tell us what you gain if you obscure that the chip is a ATmega48P-20AU versus any flavour of Mega8/48/88/168/328 in the same package.

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

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Quote:
In 1990's the smart Russian people making the homebrew Sinclairs have been widely using this technique to convert the cheap and available plasic DIP packaged 2716 OTP EPROM chips to the UV erasable EPROM - just carefully applying the smal nitric acid microdrops over the chip area until a hole reaches a light grey soft compound protecting the chip. Then the compound could be carefully removed and the chip could be exposed to UV, erased and reused for many times.


The dentist can erase an OTP without open it :) (Just take a xray picture of it)

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This also has been done of course. But dentists are rather expensive and non-portable :D

Warning: Grumpy Old Chuff. Reading this post may severely damage your mental health.

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As said before it's probably easy to identify a chip as a microcontroller and then do some backtracing to find out what chip it is.

The more important stuff such as the software inside can be protected from the "casual snooper" by programming the fuses.

Too lazy to look in the datasheet, but can the signartures still be read after the fuses are programmed?

I know of a company which wanted to protect their software, but the chip in question did not have fuses to disable readback / programming.
They used a technique with a capacitor loaded with something like 30V and discharged it through one of the programming pins via a resistor to destroy the actual readback hardware.

This has worked reliably for a year or 2.
After that there was a hardware revision of the silicon and it didn't work any more.

The folks at Rigol are still sandpapering the AD converters in their oscilloscopes and it just doesn't work. The ADC's in the DS1052E run at twice the clock frequency they are spec'd for. (See eevblog).

And the story is all over the net.
My scope still works though.

Doing magic with a USD 7 Logic Analyser: https://www.avrfreaks.net/comment/2421756#comment-2421756

Bunch of old projects with AVR's: http://www.hoevendesign.com

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I do quite a bit of reverse engineering at my day job. It makes no difference to me if the chips are sanded or not. There are not many ICs on the market that are not easily identifiable by their surrounding components. I get a general idea of how the original equipment works, then do my own thing. I don't care about the firmware in most cases. There was one case where I had to disassemble an 8051 ROM to decipher a proprietary checksumming algorithm, but that's easy when the program is in an external EPROM.

The folks you need to worry about are the Chinese counterfeiters. They will go to great lengths to directly reverse engineer something, I assume because they don't have the skills to originally engineer something, or there is someone else asking them to directly copy some particular product for them. I know of one unmentionable company that regularly does this.

I like cats, too. Let's exchange recipes.

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Quote:

The folks you need to worry about are the Chinese counterfeiters.

And not the ones in Ohio then? Do you have a legal right to be reverse engineering the equipment that you are? If not what makes the Chinese worse?

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clawson wrote:

Do you have a legal right to be reverse engineering the equipment that you are? If not what makes the Chinese worse?

When the product I produce works better than the original, and costs less, and uses a completely different circuit and original code, yes I have a legal right to do it. Let me add that there are no patents on these products either. We don't try to disguise them as original either. I reverse engineer to discover "design intent". The Chinese counterfeiters will directly copy the circuit and your firmware.

I've actually seen direct copies of one of my own circuits that was a *redesign* of another company's board. Entirely analog, and unique, by the way.

I like cats, too. Let's exchange recipes.

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Still sounds like stealing intellectual property to me. What's wrong with starting with a blank sheet of paper and actually designing something from scratch?

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clawson wrote:
Still sounds like stealing intellectual property to me. What's wrong with starting with a blank sheet of paper and actually designing something from scratch?

We make aftermarket parts. I can give you an example of the last project I did. Company A designed an engine governor for company B to use in their equipment. Company A was acquired by company C who promptly discontinued company A's product line. Company C's product wasn't good, so company B asked company D to make a replacement. Company D's replacement was no good, and their tech support was worse. So company B asked us to create a replacement for company A's product. I designed a governor that did everything company A's did, plus it has an LCD display to troubleshoot with. Company B is ecstatic. It uses an ATmega324PA. Has about half the parts count of the original (that used a defunct National Semiconductor MCU.)

That's the sort of thing we do. I'm proud of it, so I must show off a picture of my prototype :)

Attachment(s): 

I like cats, too. Let's exchange recipes.

Last Edited: Thu. Nov 11, 2010 - 09:18 PM
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But it sounds like Company C has the design rights to the original device. Did you consider contacting them and licensing (then improving) their design? If not then surely (whether their product is "bad" or not) you are taking sales revenue from company C?

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clawson wrote:
But it sounds like Company C has the design rights to the original device. Did you consider contacting them and licensing (then improving) their design? If not then surely (whether their product is "bad" or not) you are taking sales revenue from company C?

So should General Motors pay royalties to Ford Motor Company because Henry Ford created the first automobiles?

There are no patents on this and my work is entirely original.

I like cats, too. Let's exchange recipes.

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I apologize to the OP, for derailing the thread. What I meant to convey is that sanding the numbers off of your chips does not protect your IP. A patent is the only (somewhat) effective means of protecting your intellectual property. Even then, the Chinese do not respect international intellectual property laws.

I like cats, too. Let's exchange recipes.

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Hi Cat lover,

If I were company B and I asked company A to design anything for me, I'd be damn sure that I would be able to continue and improve upon my own product line after company A goes haywire.

So I would have all schematics, source code, gerber files etc.

I think there is nothing wrong with reverse engineering. If I buy any product (regardles of wether the OEM of that product likes me or not) I believe I have the right to reverse engineer it in any way I am capable.

Cloning and reselling the reverse engineered product is something else of course.

to the OP:
if you tell us what you want to achieve by erasing the labels, then we might serve you better with creative ideas to achieve your goal.

Doing magic with a USD 7 Logic Analyser: https://www.avrfreaks.net/comment/2421756#comment-2421756

Bunch of old projects with AVR's: http://www.hoevendesign.com

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If I got it right: When the PC BIOS was reverse engineered the folks "directing" it made damn sure that no-one ever had a look "inside" the BIOS (eg had read a disassembly listing). That way they made sure that they could not be sued for stealing IP.

So my amateurish view is:

Behaviour/interface isn't IP - If you design, implement and manufacture something that works as a replacement for another product, WITHOUT DIS-ASSEMBLYING THAT PRODUCT, then you are not stealing IP.

As of January 15, 2018, Site fix-up work has begun! Now do your part and report any bugs or deficiencies here

No guarantees, but if we don't report problems they won't get much of  a chance to be fixed! Details/discussions at link given just above.

 

"Some questions have no answers."[C Baird] "There comes a point where the spoon-feeding has to stop and the independent thinking has to start." [C Lawson] "There are always ways to disagree, without being disagreeable."[E Weddington] "Words represent concepts. Use the wrong words, communicate the wrong concept." [J Morin] "Persistence only goes so far if you set yourself up for failure." [Kartman]

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Quote:
When the PC BIOS was reverse engineered

I still have an IBM technical manual that has the BIOS source code in it. Not much reverse engineering needed in that case.

Four legs good, two legs bad, three legs stable.

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Quote:
What's wrong with starting with a blank sheet of paper and actually designing something from scratch?
What's wrong with learning from what other people have made?
If that's a problem, we can shutdown AVRFreaks now.
The world even.

/Jesper
http://www.yampp.com
The quick black AVR jumped over the lazy PIC.
What boots up, must come down.

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Quote:

Not much reverse engineering needed in that case.

After not much digging at all I came up with: http://en.wikipedia.org/wiki/IBM... . That, in turn, makes references to http://en.wikipedia.org/wiki/Cle... . Together they make for some interesting reading.

So they had one team reading the BIOS sources and writing a specification from that. And another team, that swore they'd never ever seen any of the BIOS sources, that wrote another BIOS from the specifications.

Also note this:

Quote:
Clean room design is useful as a defense against copyright and trade secret infringement because it relies on independent invention. However, because independent invention is not a defense against patents, clean room designs typically cannot be used to circumvent patent restrictions.

As of January 15, 2018, Site fix-up work has begun! Now do your part and report any bugs or deficiencies here

No guarantees, but if we don't report problems they won't get much of  a chance to be fixed! Details/discussions at link given just above.

 

"Some questions have no answers."[C Baird] "There comes a point where the spoon-feeding has to stop and the independent thinking has to start." [C Lawson] "There are always ways to disagree, without being disagreeable."[E Weddington] "Words represent concepts. Use the wrong words, communicate the wrong concept." [J Morin] "Persistence only goes so far if you set yourself up for failure." [Kartman]

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Quote:

I think there is nothing wrong with reverse engineering. If I buy any product (regardles of wether the OEM of that product likes me or not) I believe I have the right to reverse engineer it in any way I am capable.

IMO all of the respondents above are near the "Don't steal" end of the spectrum.

I'm with Paul as in the quote above.

Quote:

Cloning and reselling the reverse engineered product is something else of course.

Now we get into an area whew Cliff is WAY to the end of the "Don't steal" spectrum, and I'm not quite that far. If I'm doing encoders and tear apart one that works pretty well and we find that they are using the XYZ magnetic-flux chip, I personally have no problems with exploring using the XYZ chip, and in roughly the same manner as that product. If there is an industrial sensor that works quite well but is only sold as a package with a controller/indicator, I personally have no problems with decoding the "protocol" on the wires so that I can use the sensor as part of my app.

Practically, also, my tiny outfit is going to be below the radar of patent/copyright investigations. Cliff's high-volume consumer products will need to be more squeaky-clean re patents and copyright.

And I'm still using the provided WinAce that came with my XP machine, although the trial period has been exceeded by 1119 days. there; right out in public for all to see.

Lee

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

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When I mentioned disassembling that 8051 code, it wasn't actually for a product to sell either. I was building a test jig that needed to speak the same serial protocol as the DUT. This was not a typical checksum calculation used on this device. Somewhere down the road I might make a replacement for that particular device, so I will have to use the same serial protocol. It actually took me about a week of following thousands of lines of assembler to find that one tiny function that does the calculation. Compilers can be very devious in the way they optimize and arrange the final output!

I like cats, too. Let's exchange recipes.

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Quote:

an area whew Cliff is

Wabbit season? [Sorry. Had to...]

As of January 15, 2018, Site fix-up work has begun! Now do your part and report any bugs or deficiencies here

No guarantees, but if we don't report problems they won't get much of  a chance to be fixed! Details/discussions at link given just above.

 

"Some questions have no answers."[C Baird] "There comes a point where the spoon-feeding has to stop and the independent thinking has to start." [C Lawson] "There are always ways to disagree, without being disagreeable."[E Weddington] "Words represent concepts. Use the wrong words, communicate the wrong concept." [J Morin] "Persistence only goes so far if you set yourself up for failure." [Kartman]

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JohanEkdahl wrote:
Quote:

Not much reverse engineering needed in that case.

After not much digging at all I came up with: http://en.wikipedia.org/wiki/IBM... . That, in turn, makes references to http://en.wikipedia.org/wiki/Cle... . Together they make for some interesting reading.

So they had one team reading the BIOS sources and writing a specification from that. And another team, that swore they'd never ever seen any of the BIOS sources, that wrote another BIOS from the specifications.

Also note this:

Quote:
Clean room design is useful as a defense against copyright and trade secret infringement because it relies on independent invention. However, because independent invention is not a defense against patents, clean room designs typically cannot be used to circumvent patent restrictions.

OK, Johan, I didn't understand your point initially. Now I have re-read the post I think I do.

Incidentally, the very first PC app I wrote(for money) was a terminate and stay resident (TSR) screen capture utility. I disassembled Sidekick to find out how TSRs worked, and how to hook into the various event vectors. The end product was nothing like Sidekick, so I never felt that I'd done anything wrong. I have done some bad things in my time however, such as re-writing several arcade games to run on "legacy" Galaxian hardware. A long time ago, and I got my come-uppance!

Four legs good, two legs bad, three legs stable.

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Not to hijack this thread but...

Thats a nice LCD ninevoltz, what brand is it? I am looking for a nice display for a project and that caught my eye.

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It's a transflective LCD. Visible in direct sunlight. Backlit for when it's dark. Almost as nice as e-ink.

It's made by Optrex. C-51848NFJ-SLW-ADN

I like cats, too. Let's exchange recipes.

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Thanks a lot, I'm going to pick one up.