How do you lay your thermal paste? Thick or thin???


And then, have you ever removed the HSF to see how it spread after mounting???

Thin, paper thin. I use a razor blade and run a smooth layer across the surface.

What you need to do is lap whatever device you are putting on so that the thermal grease has maximum surface contact.

Use something non-conductive like Ceramique, gob a large dab on it and spread it out thick, there should be about 1-2MM of paste if you ask me, thinly spreading thermal paste is a crock. Better temps thickly spread...

Naturally, when two flat surfaces are joined by a thick paste, each surface will have many peaks and pits when they are seperated, however when they are compressed together, the TIM is holding a soild region of thermal paste between the heatsink and the die.

I put a good size dab in the center and spread it around with my finger (with my finger in a sandwhich bag). Make sure its covered, unformity is necessary as the pressure of the heatsink and clips will spuuge it around as necessary - just dont get to carried away. With that said my vote is for....

not to thick or not to thin........just right.

I use Artic Silver 5 Hi Density Thermal Paste, and orignally applied the suggested grain of rice size compound.

I then followed the remaining instructions and rotated the Zalman CNPS7000 and CPU together to ensure an even spread. (I did this off the mobo) so i had to separate the cpu and Zalman get it back on the mobo. It was at this stage that i realised that it appeared not to be enough compound so i added agood amount more for good coverage.

I spread it out around the CPU and then place the CPU back into the mobo.

After placing the Zalman back ontop and securing it, i proceeded with the rest of my build.

Only later to discover that something was wrong and i couldnt boot the PC! Frustratingly, i itested all components except the CPU and mobo as they were left till last.

So for the 3rd time i had to remove the Zalman from the CPU and although it is a paste and not a glue, it seemed to stay together really well. Anyway, cutting a long story short, when separated, the compound stuck to the CPU and only about 25% was on the Zalman. Interestingly though, the compound on the Zalman mostly was the excess compound that was squeezed out fromthe sides and very little actually stuck to the smooth part of the Zalman core.

Hence the reason for this thread! Following the instructions, seems to provide slightly inadequate coverage, but on the other hand a decent amount proved a bit too much.

The fact that the Zalman CNPS7000-CU is a very heavy HS and it is supported by the guide rails, i was uncertain that contact was being made between the CPU and the Zalman, and thats why i used more artic silver 5 thermal compoud.

I guess now that when the replacement mobo arrives next week, i will apply a 1/2 grain of rice size to both the CPU and Zalman then spread it with my fingers for decent coverage then install with a slight twist to remove any air bubbles between the compound.

Does this sound like a good method?

Quote: Originally Posted by TekXoID Use something non-conductive like Ceramique, gob a large dab on it and spread it out thick, there should be about 1-2MM of paste if you ask me, thinly spreading thermal paste is a crock. Better temps thickly spread....

Why do you put grease on at all? The only reason to add thermal interface material at all is to compensate for the uneven surfaces between the CPU die and the cooling device.

Now, how big do you actually think the peaks and valleys are on a CPU die or a cooling device? If you have even a half-assed cooling device the differences are going to be microscopic. I'm talking .00# of an inch.

The most effective cooling would be pure die to cooling device contact with no peaks, valleys, or thermal interface material. The interface material between contacts that would touch each other is actually hurting your cooling ability. It is nowhere near as effective as clean parts touching.

That's why you use a super thin coat; you don't want to interfere with the areas that make contact, but you want the TIM to fill the microscopic areas that aren't making contact.

By globbing on a bunch of TIM and spreading it out, you actually insulate your CPU which increases your heat.

Quote: Originally Posted by BigAkita Why do you put grease on at all? The only reason to add thermal interface material at all is to compensate for the uneven surfaces between the CPU die and the cooling device. Now, how big do you actually think the peaks and valleys are on a CPU die or a cooling device? If you have even a half-assed cooling device the differences are going to be microscopic. I'm talking .00# of an inch. The most effective cooling would be pure die to cooling device contact with no peaks, valleys, or thermal interface material. The interface material between contacts that would touch each other is actually hurting your cooling ability. It is nowhere near as effective as clean parts touching. That's why you use a super thin coat; you don't want to interfere with the areas that make contact, but you want the TIM to fill the microscopic areas that aren't making contact. By globbing on a bunch of TIM and spreading it out, you actually insulate your CPU which increases your heat.

Thats bs the grease lowers the thermal resistance. It makes a big diffrence when you don't use the grease. If you go to mouser and look at heatsinks they tell you the thrmal resistance if you were to try two diffrent ones that had a diffrent number you would see that the heatsink with the lower thernal resistance works a LOT better and using thermal paste lowers the thermal resistance by a significant amount. There are many pits on the suraface of a heatsink. They should all be filled. Just putting the heatsink on won't make enough contact to be very efficient. You NEED paste. If you have your heatsink secured tightly the way it's supposed to it will not be isolating the die. Thernmal grease is designed to bridge a path for heat and in any case it is better to use it. If it was as unimportant as you think then we wouldnt use it. It's kind of like soldering withoput wetting the tip of the iron. If youre using a really dry tip without any solder on it, you won't be able to transfer enough heat to actually solder.

Quote: Originally Posted by Tom540 Thats bs the grease lowers the thermal resistance. It makes a big diffrence when you don't use the grease. If you go to mouser and look at heatsinks they tell you the thrmal resistance if you were to try two diffrent ones that had a diffrent number you would see that the heatsink with the lower thernal resistance works a LOT better and using thermal paste lowers the thermal resistance by a significant amount. There are many pits on the suraface of a heatsink. They should all be filled. Just putting the heatsink on won't make enough contact to be very efficient. You NEED paste. If you have your heatsink secured tightly the way it's supposed to it will not be isolating the die. Thernmal grease is designed to bridge a path for heat and in any case it is better to use it. If it was as unimportant as you think then we wouldnt use it.

You are honestly telling me that thermal interface material is more efficient than direct contact? Dude, you are a fool!

Why even lap? Just stick a big ass glob of paste in there. Why do the heat numbers of sinks that have been lapped are better than those that weren't? I guess it's cause they stuck a big ass glob of arctic silver in there.

I want to see where thermal resistance is DECREASED when the amount of matter in between the surfaces is INCREASED.

Whatever BA, I get lower temperatures my way.

I don't disagree with the fact that thermal material is needed, but the only reason it is needed is to fill the microscopic gaps between the surfaces. It is not a better conductor of heat than absolute surface to surface contact is.

A high amount of TIM ensures that when pressure is applied by the heatsinks retention, that the paste spreads out evenly and the excess paste oozes out the sides of the die.

Quote: Originally Posted by TekXoID A high amount of TIM ensures that when pressure is applied by the heatsinks retention, that the paste spreads out evenly and the excess paste oozes out the sides of the die.

oozing can be a bad thing. You don't want it getting somewhere it shouldn't.

Thermal paste? Bleh - I just spit on the die throw 'er together and she's good to go.

Actually I put down a small dab and spread it out from the center in the four directions with a card from my wallet..

Not when it is not conductive....Ceramique.

Man you people put way to much thought into this, i put on some on (whatever i think is the rite ammount, its common sense DUHHGH!!) then even it out a bit with my finger (although its not really needed becuase the HS clip is putting down at least 5 pounds force onto the die, and that evens it out just fine), then install the heatsink......jeez...

There is a proper way to do it. This thread ain't it. You don't glop, slap, put down, or just drop TIM onto a CPU. If none of you believe me, check out the instructions at the place you got your TIM from. This must be goddamn n00b week, and I'm starting to get a little pissed off.

Can someone post some "good" links of "lapping VS non lapping" I might do it if its worth it....

Quote: Originally Posted by TYCOON Can someone post some "good" links of "lapping VS non lapping" I might do it if its worth it....

http://guides.pcapex.com/modding/mir...sh_lapping.php

ummm 1c...that could be a diffrence in the temp of the room...hmm mabey its not worth it after all...considering im not a "hardcore" overclocker and all...

I have to agree with BA on this one. Too much thermal compound is not the best way to go. The pits and grooves on the heatsink / cpu are extremely small. It doesnt take a whole lot to fill them up. By adding too much grease, you are actually increasing the distance the heat would have to travel to enter the heatsink from the cpu.

Think about that for a second. The sooner the heat can be dissipated into the heatsink, the better, right? So why add more and increase the distance the heat would have to travel?