I Took Apart A PIC18

[Lance]

Following the motto of this site, I didn't turn it on! I tried to turn it on, discovered it was burnt out, and then took it apart. The component in question is a PIC18. I just sanded the top off until I got down to the lead layer. I didn't have a proper sander available to me, so I just went at it with a sandpaper bit on a drill. A few times the drill got traction and pulled around, so some of the pins got wrecked. All things considered it came out rather well. Not a neat job by any means.

Did I destroy the IC? Or can I lightly remove some more to get at it?

[Time]

Why did you sand the solder mask off?

[armandas]

Dude, picture cropping - use it!!

Back to topic: interesting picture, thanks for sharing. I have extracted the silicon parts by torching ICs. It's not too fascinating without a microscope though.

[Jon Chandler]

SparkFun has had a few recent columns on dissecting ICs.  The first, a few months ago, was looking at SD cards.  The second was a counterfeit ATMEL part. Lots of awesome pictures and a discussion about how the pros do it.

[Time]

Oh, nevermind I see whats going on here.  This is an IC, I thought it was PCB for some reason.

[Lance]

Yeah I was wondering why you said that.

So how do I actually get the IC out? What else needs to be taken off? Is the grey there just more plastic to remove?

[armandas]

Yeah I was wondering why you said that.

So how do I actually get the IC out? I have access to a scope, so what else needs to be taken off? Is the grey there just more plastic to remove?

If you just want to get the silicon out, burn the thing with a torch. By sanding, you're more likely to scratch the die.

[Lance]

I would like to keep it in the body...perhaps turning it upside down and having a small flame would work? I'll do some research.

[Zad]

The guy at http://www.visual6502.org/ used hot sulphuric acid to remove the encapsulation on the 6502 (woah!).

[alm]

Yep, strong acid is the proper way. As someone who has worked with that kind of stuff (not for taking apart semiconductors), I wouldn't recommend anyone without proper training and equipment (fume hood, eye wash, that kind of stuff) to even get near it. It's far more dangerous than even mains voltage. A blow torch is much safer (as long as you don't burn yourself and it's outdoors).

[Lance]

Yep, strong acid is the proper way. As someone who has worked with that kind of stuff (not for taking apart semiconductors), I wouldn't recommend anyone without proper training and equipment (fume hood, eye wash, that kind of stuff) to even get near it. It's far more dangerous than even mains voltage. A blow torch is much safer (as long as you don't burn yourself and it's outdoors).

I'm confident I could handle it properly, but I don't have a proper fumehood or emergency eye wash station. So I'd rather not use that kind of acid. Also I don't have any on hand. Quick use of a torch seems to be the best way to go about this for me.

Perhaps Dave could do a blog on this.

[Zad]

I wish I had a macro lens, I have some old PIC12 and PIC16s that were UV erasable and so have a quartz window over the chip. The detail you can see just with a hand lens from a Swiss Army Knife is amazing!

[Lance]

I wish I had a macro lens, I have some old PIC12 and PIC16s that were UV erasable and so have a quartz window over the chip. The detail you can see just with a hand lens from a Swiss Army Knife is amazing!

I can imagine. I'll take a look around and see if I can find something like that. I've never heard of UV light being used to erase the EEPROM, although that would explain why I have seen ICs with windows on them. How does the UV light erase the memory?

[joelby]

I've never heard of UV light being used to erase the EEPROM

UV light is used to erase EPROMs, not EEPROMs.

How does the UV light erase the memory?

The UV light ionises the silicon oxide in the chip, which causes the charge stored in the floating gate to dissipate.

[Zero999]

It does show how tiny the die is compared to the package.

Perhaps Microchip should offer a chip on board option for high volume designs: submit the PCB design and the code and they'll get it made for you.

I've done this before. Where I used to work there were some old 741s in a metal case, all I did was cut the top of but unfortunately I didn't take a picture.

If you have a scanner, it's probably the best way to take pictures of small flat objects.

[joelby]

Perhaps Microchip should offer a chip on board option for high volume designs: submit the PCB design and the code and they'll get it made for you.

Microchip (and Atmel) will sell you bare dies, if that's what you mean. I doubt they want to be in the business of making your PCBs for you!

[DavidDLC]

Perhaps Microchip should offer a chip on board option for high volume designs: submit the PCB design and the code and they'll get it made for you.

Microchip (and Atmel) will sell you bare dies, if that's what you mean. I doubt they want to be in the business of making your PCBs for you!

Unless they can get a very good deal, like with big companies, then they can outsource the assembly.