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really proper way to apply thermal compound?
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Ian.M:
Take an old credit card or store card and scrape a trace of compound over both surfaces to fully wet them.  Wipe off any excess at the edges.  Apply a dot in the middle (rice grain size for most power transistors, dried split pea sized for large ICs like old Pentium CPUs) and assemble with manual pressure and a slight orbiting motion till you see squeeze-out all the way round.   Fit the retaining clips or screws before releasing the pressure.  If possible clean up the squeeze-out excess with a paper towel or a Q-tip moistened with thinners.

If you pretend you are Scrooge and the paste is loaded with gold dust you'll get the quantity about right - meaner than a Scottish miser spreading Marmite - as the thinner the layer the better as long as its void-free.
wraper:

--- Quote from: GregDunn on December 10, 2018, 06:00:59 am ---
--- Quote from: Nerull on December 10, 2018, 04:09:05 am ---People obsess over methods of thermal compound application but real word differences seem minimal to non-existent.

--- End quote ---

This.  If it were really important, they wouldn't give thermal compound, CPUs and heat sinks to gamers and trust them to not screw it up.

--- End quote ---
If it's a bare silicon die, it's important. From my experience I can say that I've seen GPU shutting down due to local overheating (but showing normal temp in monitoring app) which happened because of entrapped air bubble (just after paste application). If paste is spread over surface, some small air bubbles are almost guaranteed.
Mr. Scram:

--- Quote from: wraper on December 10, 2018, 01:39:30 pm ---If it's a bare silicon die, it's important. From my experience I can say that I've seen GPU shutting down due to local overheating (but showing normal temp in monitoring app) which happened because of entrapped air bubble (just after paste application). If paste is spread over surface, some small air bubbles are almost guaranteed.

--- End quote ---
How did you make sure that was actually the problem you saw? Just reapplying thermal pastes leaves room for many other issues to be corrected at the same time.

The problem with this discussion is that it's surrounded by a lot of myth and hearsay whereas the little repeatable actual evidence that exists shows pretty much all of that is irrelevant. More evidence is very welcome, but we should be very mindful about what is accepted as such.
Mr. Scram:

--- Quote from: coppercone2 on December 10, 2018, 06:27:09 am ---whats interesting about CPU is the fact that you can replace the paste between the die and the lid of the IC in a modern intel chip to improve its performance. surprising for 1000$ ic.

but seriously, what about spin coating? Its used for extremely even distribution of photoresist during transistor manufacture.

--- End quote ---
Most of Intel's higher end offerings once more come with soldered IHSs.

What about spincoating? It isn't currently remotely applicable to CPU TIM.
wraper:

--- Quote from: Mr. Scram on December 10, 2018, 07:53:44 pm ---How did you make sure that was actually the problem you saw? Just reapplying thermal pastes leaves room for many other issues to be corrected at the same time.

--- End quote ---
Because it was newly applied thermal paste and there was an air bubble. When you are dissipating 250W of heat at 95oC die temperature over 4cm2 without any heatspreader, it matters.
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