Firstly that the thermal paste is used to ensure full contact between the surface of the micro core and the surface of the heat. Why? it because if there are gaps (and between two surfaces that are not entirely smooth, as is the case, there) the thermal conductivity of air (which is what would have within that gap) is lower than the thermal paste, ie , for thermal conductivity is better than the hole are filled with air thermal paste. But we must also say that no matter how good the thermal paste (I mean the ones in the market) will never have the conductivity index is aluminum (and in no case copper), for Thus, any amount that exceeds what is necessary is to act as a thermal resistance (and heat dissipation hurt). One comment, it is true that if you catch a chipset heatsink and take away (or the micro for a graphics card) you usually find a good dollop of thermal paste (usually white). I suppose the reasons are twofold. First, the surface of the chip is different to that of a micro AMD XP. There is no well defined core in these components (no overhang) so what makes contact with the cooler is the entire chip, so you have to apply paste on all of it (like for example if you ride a bus with intel heatspreader or a new AMD64).
It is therefore a sum check to ensure that through the pressure of the heatsink itself extends over the entire surface (as if you hit a jam sandwich.) The ideal would be to apply a film on the whole chip but in an assembly (I guess it will be for this) is easier and faster to have a machine that will put a dollop in the center and stop trifles.
Recently I had an idea I am about to see, to deduce what is the ideal case where the application of thermal paste. I want to measure temperatures in the following situations :
- No thermal paste (or holes filled with air)
- With thermal paste in the holes (Core).
- With thermal paste in the holes (Core + sink).
- With excess of thermal paste (using more pasta)
- Strictly thermal paste in the holes.
In which I think is closest to the ideal situation. Be obtained by applying a film, after placing the sink for the pressure to extend the pasta .. and then take off the heatsink cleaned with a tissue surface of both the micro and sink .. But this does not bring you back to the 1st case? because I think no, because if we imagine the core surface and sink high power view with something like we saw teeth .. on the tips of which has passed the toilet paper but not on the gaps between teeth (which are holes to fill with pasta) pasta would therefore ONLY in the gaps.
This will maximize the contact surface (the principle that applies to the pasta) but instead minimizes aquaplaning between pulp and core (that gaps do not absorb all of the paste is applied and between micro and sink area, putting thermal resistance) .. I think this would be the best way to apply thermal paste.
Finally, it occurred to me the other day re-reading forum posts and not if one leg of pot or if you have a real basis (must wait to take measurements and see what happens).
Bookmarks