Thermal pad, silver paste questions

[Perd Hapley]

One of my computers is a Dell with a Pentium D chip.  Due to some problems I had last year, Dell sent me a new mama-board and heatsink/fan for the CPU.  It included a thermal pad, and I have been using it this way for several months.  In a fit of idiocy today, I took the heatsink off of the processor, without really meaning to.* 

Should I put the sink back on, and continue trucking?  Should I worry that dust might have gotten onto it, that will now be trapped between sink and CPU? 

Or should I remove the pad altogether, and use silver paste? 

And since we're admonished to use microscopic amounts of silver paste, why do they make the pads so thick? 


*I thought I was just removing the hood between the heatsink and the fan.  I forgot the sink was attached to the hood.   


Edit:  I forgot the other half of the problem.  I would just slap the think back together and see what works, but Speedfan won't measure CPU temps on my Dells.  Is there something like Speedfan that works better on Dells? 

[Regolith]

When in doubt, I remove everything and start over with some fresh silver paste.  Can't go too far wrong with that. 

[RocketMan]

What Regolith said.  I've done it many times on various Dells.  Never a problem.

[Perd Hapley]

Sigh.  But that means I get to play the "how much is too much?" game.   


RocketMan, 

Do you know of a way to make Speedfan work on a Dell, or is there another program that will?  Speedfan works fine on my HPs, but on my Dells, it can only find hard drive temps.   

[mtnbkr]

Fisty, do you have any paste?  I have an unopened tube that came with my new computer.  It isn't "silver", but it is heatsink compound.  PM me your address and I'll mail it out to you.

Chris

[Perd Hapley]

I gots some.  Thanks. 

[Nick1911]

I've slammed them back together without ever having a problem.  But, if you're not comfortable doing so, starting fresh after cleaning everything can't hurt.  Naphtha (zippo lighter fluid) is my preferred cpu grease cleaner.

[Perd Hapley]

OK, so I nuked the old pad, and used some Antec AS5.  It seems to be working fine, but there is apparently no sensor to measure CPU temps on that mommy-board.   

I hate, hate, hate using paste, as I can never know whether I put on too much, or too little, or whether a spot in the middle is fine, or whether it needs to be applied to whole heat spreader.  Except by trial and error.  And when I can't see the temps...   

[sanglant]

how much? easy a thin coat just enough to cover. cover the heat sink and scrape off all you can with a razer blade, then put a coat on the processor(or other ic ) now scrap all but a very thin layer off, you want about half a mm left. oh check for level, if one surface is cupped or rounded, it takes more. think about lapping if it is. (i've never had the guts to try it )

walk through if you don't trust my method

oh, is arctic silver 5 still considered the best? i need to order some.

edit: oh, and everclear and a qtip is handy to clean the old paste off. just be sure it's good and dry(you to. ) before turning the computer back on.
edit 2: i forgot we had geek members, that might be closer to .125-.25 mm if your measuring.

[tyme]

Every time I take a heatsink off I put more thermal paste on before I reseat the heatsink.  Otherwise there's a risk that it might not be even, and there may be small portions that have a too-thin layer, which ends up not making good contact with the heatsink and ends up being a hot spot.

[Nightfall]

For future reference:

http://articsilver.com/instructions.htm

Just choose your product and CPU type. Has detailed instructions, with pictures illustrating where and how much.

[RocketMan]

Just follow the instructions on the Arctic Silver website for the type of TIM and the CPU you are applying it to, and you will be fine, fisty.   They have instructions for almost every make and model CPU known on this side of the galaxy.

[CNYCacher]

OK so you don't put a glob and then press them together and scrape off what oozed out once you get the heatsink secured?

[RocketMan]

OK so you don't put a glob and then press them together and scrape off what oozed out once you get the heatsink secured?

Nope.  With Arctic Silver 5 and its Antec equivalent, more is definitely not better.  With a socket 478 Pentium CPU, use an amount equal to about one (1) uncooked short-grain of white rice.  Apply it right in the center of the heat spreader.  Do not spread it out with a tool, just install the heat sink and let that spread the material.  A few heat/cool cycles will break it in just fine.
Put too much on the heat spreader, it will actually lessen heat transfer because it increases the spacing between the heat spreader surface and the mating surface of the heat sink.

[Perd Hapley]

I'm pretty sure he was kidding.   

[RocketMan]

He's one o' them New Yawk guys.  How do you know?