First ESP32-PICO-V3 cross section has a few artifacts, but I have more epoxy to use up and I want to get better at making really nice looking cross sections anyway. So I might do another. I have a few extra chips and tow more packs of epoxy to use up.

First off, I probably should have read the datasheet. It's not just the ESP32 and flash chip, there's a 40 MHz crystal and some matching components too. So it's a full SiP with embedded passives on a four layer substrate! This is a lot more interesting to look at than just a single die, which is good.

Less good: the die is way off center in the package. This is fine if you're expecting it, but I ended up sanding into the die using coarse sandpaper during the early stage of the cross section and creating some cracks which are difficult to get rid of. Lesson learned, I'll be prepared next time.