As I said, I have an ASIC here I would like to take a photograph of. I have the photography equipment, but the die is covered in some sort of yellowish transparent coat. I dont care if the die becomes non-functional.
If it is a plastic like material, then fuming nitric acid would work. Be sure to use a ventilated hood and acid protective gear. (This work is best done in a lab where they work with acids.)
If you don't have access to fuming nitric acid, then 70% nitric acid should work, but it will take longer. You'll probably need a warming plate too. The nitric acid will eat the copper leads. But you can mitigate this effect by adding sulfuric acid to the nitric acid at a ratio of 1 part sulfuric acid to 9 parts nitric acid.
If the package is plastic, then the nitric acid will dissolve the package too. Use a glass dish. Remember, nitric acid dissolves plastics. |