I always loved the easter eggs and art that some chips have included on the circuits, most of which has never been seen and will never be seen by anybody but the designers.<p>Here are some examples:<p><a href="http://smithsonianchips.si.edu/chipfun/graff.htm" rel="nofollow">http://smithsonianchips.si.edu/chipfun/graff.htm</a><p><a href="https://en.wikipedia.org/wiki/Chip_art" rel="nofollow">https://en.wikipedia.org/wiki/Chip_art</a><p>My favorite has always been Wally/Waldo from Where's Wally.
While sulfuric or nitric acid is the best way to do this, you can also decap using a box cutter and some patience. I recently did this to figure out if an opamp I bought was fake:<p><a href="http://41j.com/blog/2019/03/various-op177-die-images/" rel="nofollow">http://41j.com/blog/2019/03/various-op177-die-images/</a><p>I’ve posted some better images here:<p><a href="https://twitter.com/new299/status/1111301269988106245?s=21" rel="nofollow">https://twitter.com/new299/status/1111301269988106245?s=21</a><p>I’m going to try and get setup to decap properly. But the for those more concerned about using the required acids, a box cutter can give some insight into what’s going on in many devices...
I used to do this as part of R&D efforts at my employer 15 years back. It was pretty dirt cheap to get someone to decap a package like this. You could also get them to put under an electron(x-ray?) microscope and fly around the chip like an airplane simulation. Then they would use something called FIB to cut and draw wires to test out bug fixes. Usually the designers would keep a couple unused gates at periodic intervals to borrow for fixes.
Applied Science YouTube channel did a video on this: <a href="https://www.youtube.com/watch?v=mT1FStxAVz4" rel="nofollow">https://www.youtube.com/watch?v=mT1FStxAVz4</a>
I always liked the physical side of electronics as contrary as computer programming where is all virtual nowadays.<p>What would be the career path for a job in chip design and manufacturing?
There's some more here:<p><a href="https://siliconpr0n.org/wiki/doku.php?id=decap:start" rel="nofollow">https://siliconpr0n.org/wiki/doku.php?id=decap:start</a><p>If we can digitize the entire netlist (schematic of transistors) from the 6502 processor by analyzing this type of photograph, why hasn't someone started analyzing the crappy wifi chips that people who don't run Trisquel use--the kind that require proprietary drivers to work correctly, in order to write free drivers for them?<p><a href="https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/" rel="nofollow">https://git.kernel.org/pub/scm/linux/kernel/git/firmware/lin...</a>
As an aside, I find chips that have been covered in epoxy really annoying. Not only are they really difficult to remove, but even before that they don’t have the typical markings on their casings that serve to identify them and tell you whether they’re interesting to pursue…
When I was young, a friend of mine sawed a chip in two for this.<p>It was rather old and had small golden wires everywhere that connected stuff, they made it look like some ancient tech.
Very interesting technique. I remember when they would reverse engineer chips by grinding them down while taking nice pictures of each layer for the engineers to interpret later.