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To get the die off the flip chip carrier I use heat and scraping. Then I use a razor blade to scrape off most of the metal layers (which obscure the functional

To get the die off the flip chip carrier I use heat and scraping. Then I use a razor blade to scrape off most of the metal layers (which obscure the functional blocks), then a cheap Chinese inspection microscope ($100) attached to a DSLR with a 3D printed adapter (a DSLR with a lens attached backwards also works in a pinch). Then take a bunch of individual photos and stitch them with Hugin. Results: https://marcan.st/transf/latte_stitched.jpg https://marcan.st/transf/latte_stitched.jpg Edit: sorry, the link was previously the (lower res!) Chipworks shot I'd annotated previously. I got confused. Replaced with mine. It's less clean but higher resolution than what they released. At the highest zoom I could get I could just about make out individual bits in the eFuse array. This is a Wii U GPU (Latte). https://marcan.st/transf/latte_otp_slr.jpg https://marcan.st/transf/latte_otp_slr.jpg No chemicals needed. I'm probably one of very few people crazy enough to do this mechanically, but it clearly works! Here's a single shot done with a reversed cheap kit Canon lens of a PS3 GPU (RSX), again with the scraping method. https://marcan.st/transf/rsx.jpg https://marcan.st/transf/rsx.jpg I do happen to have access to a SEM too, and obviously that gets a lot more fun. Here's the same eFuse area (again this is still the mechanically deprocessed chip!): https://marcan.st/transf/sem/latte/20161210_201044.png https://marcan.st/transf/sem/latte/20161210_201044.png I think the mechanical delayering usually gets me to M1 or so, though it's not completely consistent depending on the specific process. Some chips work better than others.

isatty 6y ago
This is really cool, thanks for sharing
fprog 6y ago
I had no idea this could be done using relatively inexpensive tools and (to use your word) mechanical technique. It reminds me of discovering the backyard astrophotography community after long assuming photos of stellar objects could only be captured by huge telescopes owned by institutions. Thank you for sharing!
- marcan_42 6y ago
  This works on modern processes because modern chips are made using CMP (chemical-mechanical polishing) to planarize the layers. On older processes the layers were just stacked on each other without being flat in the depth dimension, so you couldn't just cut cleanly in one plane like you can now. Then again, on older chips you can usually just take a top layer shot and tell apart most of the layers anyway.

isatty 6y ago

This is really cool, thanks for sharing

fprog 6y ago

I had no idea this could be done using relatively inexpensive tools and (to use your word) mechanical technique. It reminds me of discovering the backyard astrophotography community after long assuming photos of stellar objects could only be captured by huge telescopes owned by institutions. Thank you for sharing!

marcan_42 6y ago
This works on modern processes because modern chips are made using CMP (chemical-mechanical polishing) to planarize the layers. On older processes the layers were just stacked on each other without being flat in the depth dimension, so you couldn't just cut cleanly in one plane like you can now. Then again, on older chips you can usually just take a top layer shot and tell apart most of the layers anyway.