Introduction: How to Expose the Die (contents) of an Old CPU
This is my first instructable, so there aren't many steps involved. I am just getting familiar with the site! Any comments are welcome.
Most of us have seen photos of a silicon chip die, usually magnified. In many of those chips, specially the large ones, the several logic areas are visible by naked eye. In this instructable I am showing you the steps to open-up an i486 DX2-66 CPU and inspect the contents! It's a rather large (and slow for these days :-) ) silicon chip. It's a very easy task, as soon as you are patient and gentle, because the contents are a bit fragile!
Step 1: What You Will Need
1) An i486 DX2 CPU or any other CPU with similar packaging. (I have plenty of old CPU's but I chose to kill this one because I have a couple of this model)
2) A hammer (not a very heavy one!)
3) A chisel with sharp edge
Step 2: Prepare for the Job
You have to find a steady corner in order to secure the CPU. I chose to do it on the ledge of my balcony, and position the CPU against the base of the balcony rail...
Then, position the edge of the chisel exactly at the point where the metal cover meets the underneath of the ceramic CPU packaging. You have to maintain an angle smaller than 45 degrees, (smaller than shown in the photo), in order to avoid breaking the CPU packaging. You may have to bend the pins in order to position the chisel to a small angle.
Step 3: Removing the Metal Cover
In this step you don't want to remove the cover (which is a thin piece of metal) with one move, just to unstick the edge of it, and then remove it completely by hand. When you are sure that everything is secure, start hitting the chisel with the hammer doing small and sharp moves (keep holding the chisel tightly against the CPU), until the glue that holds the metal cover breaks and the chisel edge enters underneath the cover. After that you can push the chisel by hand in order to completely remove the cover.
Step 4: Result
The final result is visible here. The detail is much more fascinating in real than in a photo, especially this low detail one that I took with my old 2 megapixel digital camera... You can get a better idea of how it will look in real by looking here: Magnified CPU die
I know there are plenty of similar photos on the net, clear and magnified, but I think it is very interesting to be able to inspect such a circuit in person. You can even distinguish the anaglyph nature of the silicon wafer just by using a simple magnifying glass! I have some microscope lenses which I plan to use in order to see some more detail, and maybe get some better photos.
If you have already done, or you do something similar, I would love to see some photos!