I don't always know as much as I think I know.Originally Posted by SiGfever
When I test in the lab on a test I am always at optimmum 90-100 psi. and what I see is a drop of 1-2C after two hours then maybe 1/2 C overnight then stabilizes.
I tried it on a few after market sinks with loadings in the 40-60lb range in systems with similar result and did not think it would be an issue. Recent Beta testing giveaways some people report back 48- 72 hrs, week later and announce another 2C-3 drop. So the time component probably is related with pressure and heat and varies some depending on the combined factors
From memory I believe that Intel recommends something like 43lbs +/-10lbs with a max board loading of around 70lbs. I would assume
from the Intel spec much under 30lbs and you will would not have enough to flatten the IHS, Actually having just filed a cut for a thermocouple recently I am surprised 40LBS does it.
I have run some cursory tests with glass slides and some uncalibrated binder clips. Cold (room temp) and maybe 15- 20lbs perclip typical paste takes about 1 to 2 min. to reach a pretty good spread with 2 clips about 30 sec with four. I took a mic to the glass and checked spread. With ICD7 maybe 5 min. with the 2clip and about a min with the 4 clip configuration. @ 50C ICD7 flows well.
So the scenario should be some spread when cold and a more rapid spread as it heats up balancing out or seeking the bondline thickness with adequate pressure. Colder systems may take a little longer.
To answer your question fire it and see what happens. if it seems high let it set for a day or so and see if trends downwards.
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