grinding down chips was Re: QX10 graphics board
pdp11 at saccade.com
Fri Jan 27 01:18:03 CST 2006
>I've been dying to ask this question. Can you
>actually learn something (hopefully a whole lot!)
>about a chip if you actually did this???
There are actually successful companies in just that business:
Be sure to click on the "Silicon Art Gallery" link at the top. For a while
Chipworks had a free CD with other interesting photos, I'm not sure if it's
Getting at the die isn't all that complicated - it's called "depackaging"
or "decapsulation" in the trade. For ceramic and PGA packages with a metal
lid, it's generally pretty easy to just pry the lid off. For plastic
chips, dripping fuming nitric acid on the package eats it away but leaves
the silicon and bonding wires in tact.
There are labs that do this sort of work on a regular basis:
Be sure to read bunnie's story of how to skirt the "security" features of a
PIC microcontroller by sticking a tiny piece of electrical tape(!) on the die.
Modern, high end chips (P4, Opteron, Cell, etc.) are pretty hard to get at
though. Rather than having bounding wires at the edge of the chip, they
have tiny solder balls scattered across it. The chips are soldered/glued
face down directly to the package interconnect. I'm sure it takes some
serious wizardry to pry them loose again.
[Why yes, I am a chip collector...how could you tell?]
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