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How to erase IC name without sand paper.

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Analyzer

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Hi there,

I would like to erase part number on ic without damaging it.I was doing this job with sand paper but everyone can understand it was erased.I want it, nobody can understand it was erased.I want ic like with no printing on it.Should i use a chamical material for this.If so, what is its name? :?

Analyzer.
 

Hishamsaleh

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Hi analyzer...

some IC's names written by a glassy pants.. this kind is hard to be removed w/t sand paper... but for most ics you can use (Tenner) to remove a paint on it.. and it's really effective.
 

S

sick_man

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i used to get stuff too look at
that had this "trick" applied

pointless realy ....
becouse with 1 drop of nitric acid the number shows up dark brown
even if you mill .5 mm from the chip surface
acid still works
you see the number like rock candy is all the way through
the best most effective way too remove a number is ask for ident free chips {of the right type} from your supplier these have only a pattern number die and for the outline on them so dont have a part number like 74ls123 it says schotkey TTL
but even this number is also irrimovable completely

unfortunatly
 

luben111

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Hi,

In my oppinion the glass paper is the only one solution. Especially with the parts that are engraved with laser. No other solution can guarantee the removement of the labels.

Well, to use glass paper you need to do some tricks. I use the following:
- on some rolling glass paper machine (Bosh) I put glass paper 200 seeds. This removes the labels within 2-3 seconds.
- With water glass paper number 320 and more into water I polish the surface - it takes not more then 5 - 10 s per chip.
- With pad printing machine I print new labels on the surface - you can't tell that the chip is with exchanged labels. BTW, more of the chips are printed with pad printing technology.

Pad printing allows any characters, labels and signs in any size to printed with extremely high quality on the any surface (more then 300 dpi). Because I'm in the business with pad printing machines I never had problems with "to remade" and "to fake" chips. You can ask pad printing services in your country from peopl ewho are in advertisment business and print ball point pens, lighters, etc.

In my opinion this is the only one good solution. Acids and chemicals can demolish the chip.

regards
Luben
 

klug

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Half year ago I had a need to erase labels of about 1000 ic's for few days, it was nightmare. I have found solution to use grinding wheel, but you need to avoid overheating and some possible static volatage breaking if you will try to polish it too with wheel. So better use some socket to fix and short pins of IC, also pay attention to fix mechanically body of IC to holder because if you will bring a lot of mechanical exertion to pins then it will make some microfissure between pins and body of IC and it can cause damage of IC in the future. Anyway your efforts with sand paper also can make microcracks if you will be too diligent.
 

flatulent

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shock and vibration

The mechanical shock and vibration of mechanical removal methods also have to be taken into account. This could ruin the reliability of the circuits inside.
 

Fragrance

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sand Blasting

Hi,

Sand Blasting If you try this method it will be very use full

this method is also used to write the number on car wind screen

Regards
fragrance
 

Analyzer

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Thanks for all reply,

@Fragrance :

Could you elaborate sand blasting please?
 

flatulent

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special tools

Sand blasting uses a special tool. A stream of air at high velocity is pointed at the object. Small particles of material like sand or even specialized material are introduced into the air stream at the source. This makes the small particles hit the object at high speed and they knock off small parts of the surface.

Companies exist that hire out their services in applying this process to the object the customer brings in.
 

Analyzer

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Hmm, Doesn't this operation damage ic? And if i understand truly, isn't it same with sand paper?
 

flatulent

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not as bad

It will remove the outer layer of everything, so you have to protect the metal pins. The mechanical shock and vibration may be lower than with sandpaper.
 

luben111

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Hi

Sand blasting is very dirty process.... I tried to use it some time ago for removing labels on keyboards. I'm afraid that in my office there is still sand from sand blasting...

And maybe it's very harmful - the dust you breath is like in mines.

Regards
Luben
 

Analyzer

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Is there any chemical for this job? ( But please advice common chemicals i can't find all of them) :)
 

S

sick_man

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do it with acetone

then srub it along the chip using a small wire wheel
this way it has lots and lots of ridges

again using a socket holder

or mill off .1 or .2 mm file and some salt grain as a good abrasive to the glass paint
 

rajasekar

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Plastic die makers use small "oil stones" to polish the dies. Its a small stick. Very effective to remove the names.

Regards
prs
 

cyberrat

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potting compound on the whole board usually makes it hard to find out whats inside it to all but the very determined person.
 

Robby

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Which Dye

Hello Luben111,

you mentioned ball printing to put a new mark on the chip.
What kind of dye (consistens I mean) is usualy using by a professional technology?

Robby
 

luben111

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Hi,

In fact there are not so many available technologies to put labels on the chip:
- pad printing
- laser engraving

Pad printing usues rubber pad to transfer the image from clishe to any surface. In fact you can use any kind of pain and colours.

As I know for IC they use 2 component dye (with hardener). And they use metalic paints, for bigger coverage of the colour.

I have 2 working pad printing machine in my office and I'm a small producer of pad printing machines and contorollers for pad printing machines. For me to put labels on the chip sounds like easy and fast task.

You can label the IC in your country by finding firms that use pad printing technology - they are in advertisment business for printing ball point pen and lighters (not silk screen technologi).

BTW, silk screen technology could be used too, but it has lower quaility of the print image.

Regards
Luben
 

hobbymat

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Also this one could be used for extremely fine sand blasting:

http://www.paascheairbrush.com/kits_and_sets.html#aec

Look under "Paasche Air Eraser Kit". It's basically an airbrush that sprays powder-like aluminum oxide. I've got one, and it can be used to almost anything. Like making one side of a miniature light bulb translucent while the other stays transparent (fine for custom-made bicycle lights... :)

Beware of static electricity (ESD) when you practise sandblasting with electronic components. You can easily create high voltage spikes when you spray an object with tiny dielectric particles.


Hobbie
 

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