PC Tech: Removing Glued-On Heatsink?

Factual Questions
1
      • I have a videocard with an OEM glued-on heatsink on the GPU. As it happens, I have pried another larger heatsink off another computer part I wasn’t using for anything (a 486 CPU)–the 486 sink is same length, width and styl;e, but twice as tall. The heatsink glued on the card is about 1.75 inches square, but the chip it’s glued centered on is only about 3/4" square, and very flat: only maybe 1mm tall off the PCB. Anybody know a good way to remove the heatsink without hurting the chip underneath?
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2

Give it a good tug. Thermal paste is more for heat transfer than permenant fixation, so it should come off pretty easily without damaging the chip.

3

Why not leave the original and just glue the new one to the old one (if you have room)? If you’re looking for additional heat drain away from that particular IC, you’re gonna get it with the addition (rather than replacement) of another heat sink.

4

I’m pretty sure that would not work. For a heatsink to dissipate the heat efficiently, it needs to have a really good point of contact with the heat source. If you glue a heatsink to a heatsink just willy-nilly you would probably not get a good contact, and could even block the airflow that the original heatsink needs to operate. No cites, just personal experience so please take with as much salt as you see fit.

Now for the OP, if there is no clamp holding the heatsink to the chip chances are you are dealing with a permanent thermal adhesive and you are out of luck. Even if you did pry off the heatsink the residue left on the chip would interfere with the placement of the new heatsink, unless you want to start sanding your videocard.

If a gentle twist does not remove the heatsink I would not try again.

5

Yeah, it’s an interesting project but with high risk re damage to the card, and relatively little benefit (a bit more cooling efficiency over the design spec). If the heatsink does not come off easily let it go. If you really want to be a cooling hound attach a small 486 sized CPU fan to it. That will be a lot more effective thermally than just a bigger heatsink.

6

I use a razor blade to pry off well stuck sinks. Run around the edge a few times, keep trying to cut in a little more on each pass.

And please avoid slicing yourself.

7
      • I am putting low-noise fans, so adding another fan isn’t attractive. The videocard has just a passive heatsink, but it works noticeably better if it has a fan on it. Right now it has a noisy slot fan, and I can’t find any quiet slot fans… I plan on ducting some of the incoming air right onto the VPU sink anyway, but it would be nicer to get the bigger sink on. I cannot possibly reach the glue itself; the VPU is only about 1mm tall off the PCB and there are other components mounted around thre sides of the heatsink, and SMC components mounted on the PCB underneath the heatsink’s overhang. — I have been advised to freeze the card and just try prying on it a bit. Will probably just do that, wish me luck…
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8

Yeah, freezing is your best bet. Put the card in an antistatic bag, put it in the freezer for awhile, then just try to carefully pop the heatsink off from one corner. Should work fine.

9

I agree with ProjectOmega. It’s probably not glue, but thermal paste which has dried out some over time.

Maybe the paste would loosen up if you heated it with a hair dryer. Just get it warm - not hotter than it would be when operating. Personally, I’d try that before freezing - I’d be afraid of cracking the board.

Be careful and good luck.

10

I’ve used “canned air” for this, if you turn the can upside-down and spray the liquid on the heatsink until it’s cold you should be able to pry it off without much force.

11

yoyodyne’s suggestion is against the product safety rec.s on the side of the can. The liquid is quite cold, under pressure, splashes easily and therefore can cause harm to you. I’ve tried this and really, really, didn’t like all that cold stuff splashing around. (Much scarier than my razor blade suggestion.)

A regular freezer works for me.