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Old April 1, 2009, 03:21 PM
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ICD7 ICD7 is offline
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Eldonko

I have know idea why they recommend a grain if rice. To answer your question with a little more detail I just put a grain of rice sized application of a random competitor's creme type paste on a simulated IHS piece of copper plate between two glass slides when clamped with 4 binder clips about (50-60 PSI) It spread about halfway to the edge then it developed little Amoeba like extensions which reform together trapping air. I have detailed this effect on the innovationcooling.com applications page but never tried it with just a grain of rice size with a competition grease but the affect holds up.Took all of 3 -10 seconds from start to finish after clamping. If I was clever and had my own review site I would make a movie of it with a bunch of pastes and post it.

The air bubbles cause a failure in the grease, Under pressure and heat they expand creating voids and early failure of the compound. Air is also an insulator, so in effect your sink is ridng on a cushion of air. This effect will impact performance and greatly decrease the long term reliability of your mount.

I doubt that I am the first to be aware of this airmixing effect, most OEM silkscreen the compound on so they must have had a reason and I am sure you can find a publication of it somewhere, adheshives are much studied, probably some old report laying around if you had an interest.

Last edited by ICD7; April 1, 2009 at 03:29 PM.
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