4 ms·

Does removing and reinstalling a heatsink damage the thermal pads, requiring buying new ones ($10 of thermal pads doesn't last as long as $10 of thermal paste)?

walrus01 4y ago
thermal pads in general are worse than properly applied paste, if you learn to paste things smoothly and accurately. there's a reason you won't seen thermal pads as the interface between a cpu's heat spreader and the underside of a skived copper heatsink in a high wattage per socket, dual CPU 1U or 2U server, where the heatsink has to be really efficient.. it'll be a factory applied paste.
- ollien 4y ago
  I think the question was more surrounding the thermal pads on things like the VRMs. My understanding (though full disclosure, I've never disassembled a GPU myself) is so long as you take care to not tear them, they should be fine.
  - walrus01 4y ago
    I don't know that I've ever seen a self adhesive double sided sticky thermal pad that was designed for re-use with re-application of a heatsink, or that I would trust re-using a second time.
CodeBeater 4y ago
In my opinion, thermal pads are better suited for components that need just that little extra bit of heat dissipation to perform adequately, i.e components that are < 10° C from being able to be passively cooled. Voltage regulators come to mind. So in that instance, if the thermal pads are reasonably well installed, the components should be just fine, since we're working with much looser tolerances. When you need active cooling, the manufacturing complexity increases to the point where the convenience doesn't really make sense, since you have to get it right, so thermal paste is the way to go.
- exmadscientist 4y ago
  Pads are preferred over paste for two main reasons: low assembly cost and ability to fill gaps. Both are very important. If you have an application using a pad, and it's flat enough to replace with (good) paste, you will always see a performance improvement. I do not ever re-use pads. I have a used pad on my desk at work that shows an indent of the chip that was pressed into its other side... and you can read the part number and lot code laser marked into the chip. If the pad conforms to that but then can't relax back... it's never going to make good contact again. Full stop. (Granted, this was an extremely expensive thick gap-filler pad [TG-A9000, I think] for a particular application, and performance will vary.)
  - masklinn 4y ago
    > If you have an application using a pad, and it's flat enough to replace with (good) paste, you will always see a performance improvement. if the tolerances are tight enough, if the heatsink doesn't even touch the VRM thermal paste won't do nothing.
    - exmadscientist 4y ago
      That's a fair point -- I was assuming contact and already moving on to surface roughness!

walrus01 4y ago

thermal pads in general are worse than properly applied paste, if you learn to paste things smoothly and accurately. there's a reason you won't seen thermal pads as the interface between a cpu's heat spreader and the underside of a skived copper heatsink in a high wattage per socket, dual CPU 1U or 2U server, where the heatsink has to be really efficient.. it'll be a factory applied paste.

ollien 4y ago
I think the question was more surrounding the thermal pads on things like the VRMs. My understanding (though full disclosure, I've never disassembled a GPU myself) is so long as you take care to not tear them, they should be fine.
- walrus01 4y ago
  I don't know that I've ever seen a self adhesive double sided sticky thermal pad that was designed for re-use with re-application of a heatsink, or that I would trust re-using a second time.

CodeBeater 4y ago

In my opinion, thermal pads are better suited for components that need just that little extra bit of heat dissipation to perform adequately, i.e components that are < 10° C from being able to be passively cooled. Voltage regulators come to mind. So in that instance, if the thermal pads are reasonably well installed, the components should be just fine, since we're working with much looser tolerances. When you need active cooling, the manufacturing complexity increases to the point where the convenience doesn't really make sense, since you have to get it right, so thermal paste is the way to go.

exmadscientist 4y ago
Pads are preferred over paste for two main reasons: low assembly cost and ability to fill gaps. Both are very important. If you have an application using a pad, and it's flat enough to replace with (good) paste, you will always see a performance improvement. I do not ever re-use pads. I have a used pad on my desk at work that shows an indent of the chip that was pressed into its other side... and you can read the part number and lot code laser marked into the chip. If the pad conforms to that but then can't relax back... it's never going to make good contact again. Full stop. (Granted, this was an extremely expensive thick gap-filler pad [TG-A9000, I think] for a particular application, and performance will vary.)
- masklinn 4y ago
  > If you have an application using a pad, and it's flat enough to replace with (good) paste, you will always see a performance improvement. if the tolerances are tight enough, if the heatsink doesn't even touch the VRM thermal paste won't do nothing.
  - exmadscientist 4y ago
    That's a fair point -- I was assuming contact and already moving on to surface roughness!