I decompose the "Nintendo 3DS" CPU using sulfuric acid

Markus is a student at the Rensselaer Polytechnic University who has the experience of disassembling the Xbox at the age of 12 and remodeling using the MOD chip and devoting passion to hardware hacking. And although it was released in 2011, the kernel was successfully accessed by a hacker, firmware was also dumped "Nintendo 3DS"We challenge the CPU from the aspect of hardware, not software, and we are disclosing the situation.

Depackaging the Nintendo 3DS CPU
http://gaasedelen.blogspot.jp/2014/03/depackaging-nintendo-3ds-cpu.html

To disassemble memory, markus used Nintendo 3DS motherboardEBayPurchased from $ 5 (about 520 yen). Also I got a motherboard from Nintendo 3DS LL from a college classmate.


This is the CPU that will be disassembled this time.


Just breaking down is not fun, so cut the motherboard and check how many sections the circuit cross section is.


After cutting and checking it, the motherboard was divided into 8 layers even if it can be seen only.


The entertainment will return to the decomposition of the CPU so far. After being soldered to the mother board, the CPU is fixed in place with adhesive. To remove the CPU from soldering or adhesive resin, heat the motherboard placed on an image-like device.


While heating the motherboard from the bottom, send hot air with a hot air gun to dissolve the resin adhering to the CPU.


When removing the CPU, brown resin remained on the motherboard.


This is the CPU removed.


Next time, to remove only the contents of the CPU, leave the CPU on sulfuric acid for a while.


After a while the reddish brown color of sulfuric acid changed to black.


After 20 minutes, remove the CPU from sulfuric acid which turned black.


Clean refreshing CPU with sulfuric acid.


Remove the attached fiberglass and observe the "CPU die" which is the CPU circuit with a microscope.


If you observe the CPU die size 6.6 mm x 6.4 mm x 0.27 mm with a microscope, you can check the scratches attached in the process of removing deposits.


Close up the CPU die. According to Markus, the CPU die seen with a microscope is said to be very beautiful.


Markus is taking a lecture called "hardware reverse engineering" which analyzes hardware by disassembling hardware at university and expert knowledge surpasses the general level, so "I do not quite understand but it looks interesting" Even if I think, it seems better not to imitate it.