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Old April 1, 2009, 09:33 AM
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Originally Posted by Soultribunal View Post
I would like to Know, if it is typical with the IC24 I got, to have improved Temp Over time after Thermally Loading and cooling the Processor.
I noticed (as stated in my post) that I had a slight improvement after it had been in use for a little while.

From my own Lab testing 50 to 100 lbs pressure loading with power loads 60W to 200 W it generally takes about two hours to hit peak, you might gain an additional 1/2 degree overnight. I have a system running about 3 years stable within a couple 10th's of a degree since the first 24 hours application. That's what I know.

That being said on just about every forum there are a couple that report improvement after a few days or even a couple of weeks of curing. I believe the reports I just do not understand the nuances behind the results, like some pressure or temperature threshold or a texture/finish issue I am not aware of. That's what I do not know

Typically what happens when you mount the sink and turn on the system the paste heats up and starts to flow and with adequate pressure (50lbs.+) it resolves down to your average particle size which becomes your bond line thickness (BLT) Thinner the bond line the better, the more conductive the material the better. It's a little of a balancing act to optimize.

Just a general information note regarding the importance of flatness.

Figure #1 is an idealized contact.

Sink and IHS are perfectly flat. With proper pressure and heat the paste flows and the gap separating sink and IHS closes or resolves down to the average particle size - the size of the particle determines the ultimate bond line thickness (BLT) Smaller the gap the better the performance in conjunction with material thermal conductivity determines performance. My experience is that too much paste will not affect performance -excess is just forced out

Figure # 2 is an illustration of the interference of high spots between the mating surfaces.

If the high spot is the same height as the particle thickness, Particles on top of that high spot will add a whole new layer of compound to the interface, 2X the amount of paste in the BLT increasing the resistance and negatively impacting performance - Flatness is the first priority when seeking best performance when lapping.

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