How to Expose the Die (contents) of an Old CPU


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!



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    27 Discussions

    Hi nice instructable! I've done this to some chips I have and would like to remove the silicon processor itself. Any thoughts on how to cut away or remove the rest of the ceramic housing?

    Cool! umm. just wondering... arnt thos pins pure gold? or are they gold plated??? and are the Origional 1s (pentium 1-2) pure gold???

    4 replies

    Outside the die they are gold plate but the inner wires are a gold alloy, still not pure gold and nothing worth "salvaging".

    That's what I always thought, but recently I saw an episode of either "How do they do it" or "How it's made" or something. They showed a company who took whole scrapped PCs from businesses for a small charge then stripped them down for salvage. One of the things they did was take CPUs and dissolve them in vats full of nitric acid+hydrochloric acid(I think) and they were left with a gold precipitate. As I recall, they then sold this on to companies who used it in industrial applications rather than jewellery. This salvage company had CPUs by the tonne though, it's definitely not worth it for the average home user. The cost of purchasing chemicals (if it's even possible), the time taken to process the processors safely and the cost of disposing of waste materials would far outstrip the value of any gold.

    I scrap on the side. picking up metals to take to the scrap yard for decent money. I had 15 or 16 banana boxes that I got from a local store. Boxed up all old hardware that I picked up. It was just under $1000 worth of material. Everything was sorted out, psus, ram, mother boards, processors, video/network/sound/modem cards. It's worth it if you know what you are doing and know where to take the material to.

    there was a guy on Oprah about 12 years ago that did that, it took him like 30 computers to get a few grams of gold.

    Cool! Now put a clear plastic cover instead of this metal thing and fix the bent pins and you will have a working processor that you can take off the motherboard and look at. It's like some sort of watch I've seen. They were very expensive, but looked very cool because you could actually see what's happening inside the clock.

    You can do this by heating the CPU with a heat gun, wait until the solder melts and flip the CPU over, the cover will fall.

    I tried to open a pentium 1 and a pentium 2, but failed on both accounts. The new chip die's are upside down, so the face that has the design is covered in a coat of plastic. In both cases I accidentally chipped the die anyways, even though I applied very little pressure to open the covers. The only way I know of exposing a die in this scenario is to drip a few drops of nitric acid on the plastic, but I think it would have a good chance of eating right through the silicon chip. Also I take no responsibility if anyone tries that cause nitric acid is really not a safe thing to use unless you're a scientist or something. Also I got a question for anyone out there, are the ceramic cpu's the ones with the die's facing you, or does it just depend on the cpu company? Im gonna have to try the last chip Ive got which is an old Cyrix 486.

    I've opened lots of (Intel) CPUs but kept all pins intact. I did not use such a rough tool but a very small jewlery screewriver. I engraled the soldering between the plate and the housing to get a small kerf between the plate and the housing - that used the same screwdriver and a hammer to blast off the plate with one smart hit. this only worked with the metal lates on e.g. old pentium one and 486, 386 and 286 - but not with the cermic plates I found on the Pentium Pro CPU

    3 replies

    birdshot worked on this ADM K5 and everyone tells me they bulletproof ,i cant get a clean shot of the back


    Here some quick and not real good pictures - description can be found below the processors (all Intel :-)


    The 386 chip has the initials of the people who designed it on the silicon. and I also looked at a pentium overdrive chip and noticed that they had the different sections marked off and labeled. Wish I still had a microscope :P

    maybe use a microscope to see in there better ! :) nice structable, i was wondering how to do this about a week ago when i had a processor laying around, so i beat the crud out of it w/ a hammer, but that didnt turn out to well. it flew around the room, not good

    1 reply

    I have some microscope lenses, but its all messed up, i need time to fix the microscope first! I tried in the past a couple of ways to do this, this one turned to be the best for me. You could always try any of the other ways described in the comments that may be easier for you.