I edited that post a few times and then ended up just rewriting it, so I apologize! I’ll rewrite how to do it below. I watched a video on YouTube to learn how (can’t recall which one), but it’s simple enough and I’ll outline the steps again. I apologize in advance for repeating myself a lot through this, but I really want to stress certain points to minimize any risk.
I use a heavy cast iron vise, but it’s just what I have around. (Got it for free at a garage sale years ago, and it’s come in handy for so many things… a used heavy duty vise is an amazing tool to have, but I digress!)
First, open the vise jaws so that it’s about as wide as you’d need to fit the CPU in flat. You actually want to put it in at a bit of an angle, though: one jaw goes on the edge of the CPU’s PCB, the other jaw goes on the lip of the IHS. You probably can go “flatter” by putting the vise on the lower edge of the IHS closer to the PCB, but I worry about damaging it that way and haven’t had a problem.
Look at the engraving on the IHS. When the text is right-side up, the right-hand edge of the IHS is where you want to push from. That is, you want to slide the lip of the right side of the IHS towards the left edge of the CPU module’s PCB. Forcibly sliding the IHS like this will break the solder and epoxy bonds holding them together, so this is the goal, and there are tiny components under the IHS that you want to avoid because there’s a chance things can dismount sort of violently risking damage to those small components. the right side of the CPU die is clear of them, so this orientation will clear that.
[ Intel Xeon ] ← push the IHS this way.
Anyway, mount the CPU in the vise UPSIDE DOWN so that the LGA pads are pointing up, the lip of the right edge of the IHS is against one vise jaw, and the CPU’s PCB is against the other jaw, and tighten it just enough to keep it in place. (Please look up a photo or YouTube tutorial because I worry I’m not being clear enough!)
I’m left-handed, so for me the vise crank is on the left side at this point with that jaw against the PCB, and I’m going to be using my right hand to steady it and prepare to catch the CPU and IHS. If you’re right handed you’ll probably want to turn the vise around, but you still need to really make sure that the CPU is oriented correctly!
At this point, optionally heat the CPU with a hot air gun or hair dryer or something to soften things. Do not use anything like a lighter or a flame, and you definitely don’t want to get it too hot to touch it. I didn’t use heat at all for all four I’ve done and it was fine, but it’ll be more controlled and less violent (and probably require less force!) if you do heat it. I’m going to heat up the X5675 that I delid tomorrow.
Once the cpu is mounted in the vise and is optionally heated up, place your hand around the chip, preparing to catch it, because it will probably fall out when you’re done and you want it to not go flying! Don’t grab it, definitely don’t squeeze it, just prepare to catch it if it falls or violently flies.
I hold my palm down against the vise, with my fingers curled gently around the entire CPU module. Don’t squeeze, and don’t get your fingers too close to the vise jaws. You don’t want to hurt yourself. You just want to catch it when it falls, with your fingers around the edges so that nothing can fly away…
Oh, and if you have an ESD wrist strap you should probably be wearing it, because I don’t see this being possible to do without touching the LGA pads.
Begin to tighten the vise jaws slowly and steadily, feeling how much force it takes to tighten. I need to use both hands plus the table I’m working on to keep it steady, so I have to be mindful to keep my hand in the right spot so that I can catch it.
After you’ve tightened it a good bit more (you might notice the PCB flexing very slightly) you’ll feel the amount of force you need to tighten the vise will drop considerably! Stop tightening! This is when you have to really be careful.
Take a breath, and then turn the crank SLOWLY and with a very constant pressure, with your hand in the right spot. If you’re lucky it will gently come apart into your hand, possibly with a satisfying sound. If you’re less lucky it’ll violently fly, possibly sooner than you expect. If you’re REALLY unlucky or did something wrong you’ll be going on eBay to get another CPU
At this point the IHS has been removed but you are NOT done! In between the IHS and the silicon CPU die is a special thermal compound called solder thermal interface material, or STIM. It’s soft metal that is adhered to the silicon, and you need to remove it in order for the heat sink to make direct contact with the CPU die. It has to be as flat and smooth as possible.
There are a few ways to remove the STIM, and the way I did for the first couple of chips was by scraping it off with a razor blade. This is kind of dangerous because you can slip and hurt yourself or damage the CPU.
A better way is to use a liquid metal that will dissolve the STIM, and then you can clean them both off. I’ve heard
really good things about Rockit Cool Quicksilver, and I have a large syringe full on order, but I haven’t personally tried it yet. Its main ingredient is gallium, and you might be able to do this with pure elemental gallium which is relatively inexpensive and not too hard to find online. (You can buy a test tube of gallium on Amazon.com for like $10.)
If you use a liquid metal to “eat” the STIM, you need to be very aware that it will also eat aluminum and is extremely potent. Do not get it anywhere near your Mac Pro tower, or you’ll be really sorry. Follow directions included, or look up a tutorial specific to it, because I definitely don’t feel comfortable trying to come up with that yet!
Once you have it all cleaned up, you’re set! I take a metallic Sharpie permanent marker and write the model of the chip on the PCB after, because all of the identifying markings are on the IHS you’ve removed.
Apply a small amount of thermal compound to the CPU die only when reassembling.
