Hardware How TIM Works & How To Apply It Correctly

Discussion in 'Article Discussion' started by Tim S, 16 Feb 2009.

  1. Tim S

    Tim S Well-Known Member

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    http://www.bit-tech.net/hardware/2009/02/16/all-about-tim/1

    When you're building your own system, it's important to understand what is happening inside. One thing that's often overlooked is thermal interface material - a simple concept, but one that's often misunderstood. We explain how it works and share some tips to help you get the best out of your system.

    :eyebrow:
     
  2. BioSniper

    BioSniper New Member

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    Interesting method there and not one I've seen before.
    I still use the old razor blade/credit card spreading method myself. Next time the CPU is pulled from my system or I upgrade I may give that one a go though :)
     
  3. NysoO

    NysoO Handcrafted

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    A whole article and we come down to a faulthy method of applying TIM. After you've applied the TIM with the size of a ricegrain in the middle, the only thing you have to do is to clamp down the heatsink and the TIM will automatically spread perfectly in all the grooves. The TIM will be pushed out in the middle and press away all the air creating a nice contact.
    If you use the "spread before clamp down"-method you'll have a high risk of trapping air between the CPU and heatsink.
     
  4. Clesm

    Clesm New Member

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    Yeah right try that with a burger and some Tommy K think you'll find you wont get an even distrubution and may be wear a red stained shirt.
     
  5. Jipa

    Jipa Avoiding the "I guess.." since 2004

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    Woah :D And it's not even April first yet...

    Seriously just w t f did I just see? I'd love to see some temperature testing, this finger-stuff against the widely applauded rise grain-method...
     
  6. harveypooka

    harveypooka Fond of rumpots and crackpots

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    I thought it was a great article!
     
  7. talladega

    talladega I'm Squidward

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    boy did i not apply my TIM correctly on my waterblocks! lol oh well i cant be bothered to take them off.
     
  8. Gremlin

    Gremlin New Member

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    this is also the wrong method really for anyone using a direct touch heatpipe based heatsink because it wont spread evenly you need to use a little bit of TIM to fill in the gaps between the copper heatpipes and aluminimum block etc for best results

    This isnt your typically high quality Bit-Tech article tbh its pretty piss poor and in its current state not worth publishing and the way it ends is almost as if theres more pages missing *shakes head* since the move to dennis bit is really slipping and it makes me sad :(
     
  9. Pookeyhead

    Pookeyhead It's big, and it's clever.

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    I've ALWAYS done it this way. This put a small blob in the middle and then apply the HSF is a stupid way of doing it. Whenever I've done that, then removed the heatsink, there are vast areas of the chip without thermal paste on it.

    Grain of rice sized amount... spread to an even, thin film with finger. Works everytime.

    Rubbish.


    Prove it.


    Whenever I've used the "accepted" method as you state, after removing the HSF, even after months, there are huge areas of the chip uncovered.

    How the hell can spreading it with your finger "trap" air under the compound? LOL

    Say what you like, but while that article may not win a pulitzer any time soon, it's spot on technically. If you're putting a grain of rice size blob down, then just clamping the HSF on, you're an idiot :)
     
    Last edited: 16 Feb 2009
  10. yuusou

    yuusou Well-Known Member

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    I use the card method myself as well. Or one of those ice cream plastic spoons with a square straight end.
     
  11. -Blue-

    -Blue- New Member

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    i use a movie theater ticket to spread it :) works great.. but i do use a little bit more than a rice grain
     
  12. Sebbo

    Sebbo New Member

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    the "clamp down the HSF" method is the method generally cited by TIM manufacturers, hence why most people stand by it. though, generally when I hear/see it the size of TIM applied is more like a pea rather than a grain of rice. i guess ultimately the desired aim/effect is the same - to spread the TIM evenly over the surface of the heatspreader. the main difference i can see is that one has the applicant doing it manually, where the other uses the pressure of the retention clips pulling the heatsink down onto the heatspreader to force the TIM away from the middle towards the edges. I usually use the clamp-down method, but then take off the heatsink to make sure it has indeed spread completely
    Any chance of a comparison between application methods in the form of delta temps etc?
     
  13. Kode

    Kode New Member

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    the problem with applying a rice grain amount then just clamping it down is that if you dont do it perfectly the application of the paste wont be right, though im not sure the whole surface needs to be covered though, personally i think its a great article, perhaps the different methods people use and state the pros and cons for them, but applying TIM is always an area newbies are unsure of, so well done bit-tech :)
     
  14. Xtrafresh

    Xtrafresh It never hurts to help

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    Nice idea there with the plastic bag. I had to do a rebuild this weekend, and I had no thermal grease on hand, so what i did was just rub the old and the new heatsink against eachother to get some goo on the new one... then just applied :duh:

    I'll obviously have to rebuild, but it works for now, and temps actually improved because i use a better block now :D
     
  15. Jipa

    Jipa Avoiding the "I guess.." since 2004

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    As I said, I ain't swallowing any of this before seeing temperature tests. The tests, btw, would have made the article so much better...

    Ofc one can use which ever method you ever wish, but without testing the temperatures there's no point calling one "the right way of doing it" especially not, when it's more work than the generally used method :wallbash:
     
  16. Pookeyhead

    Pookeyhead It's big, and it's clever.

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    Of course it all has to be covered. The larger the area in contact with the heatsink, the greater the thermal transfer from the chip to the HSF. Any areas uncovered are therefore not in good contact with the HSF. The fact that there is no compound on those areas is mute evidence that there is little or no contact between them and the heatsink, therefore reducing the ability to transfer heat from one object (CPU) to another (HSF).

    Rudimentary stuff really.


    Just ignore the bollox you read on the internet and use your common sense.
     
  17. kenco_uk

    kenco_uk I unsuccessfully then tried again

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    Nice article. I've always applied thermal goo by spreading it with a flat card. What I try and end up with is a thin layer that covers the core/ihs on the cpu but also put a very thin layer on the heatsink itself and rub it in with a cellophane-covered finger. It ensures (for me) that the gaps on the bottom of the heatsink are filled in and that hopefully any I've missed are compensated by the thin layer on the cpu.

    I forgot to rub it into the heatsink on my current setup and have noticed that each pair of cores on my C2Q have different temperatures (5c difference at idle!) but I haven't been too bothered to redo it as they are fairly low (28/33c at idle in RealTemp). So it is definitely noticeable if you don't get the coverage quite right.
     
  18. Jipa

    Jipa Avoiding the "I guess.." since 2004

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    Provocative way of discussion is always called for in the internets :blush:

    You can also use your common sense to think how thin the IHS is, how small the die is under it AND how much heat the IHS conducts to the edges of it? Again something worth testing, maybe...
     
  19. Sifter3000

    Sifter3000 I used to be somebody

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    Thermally testing TIM is actually really, really difficult. To make the test fair, you have to use the same CPU and the same HSF. The problem is, they're only pristine - i.e., 100% clean - *once*, which is when you first get them out of the box. Having talked to engineers at HSF and TIM manufacturers (Akasa and Zalman) while researching the article, we were told that although TIM clean gets most of a layer of TIM off, it doesn't remove it all - this is because TIM is really designed to be applied once, not constantly applied and removed.

    As a result, as the test goes on, you're going to get a build up of TIM on the CPU and the HSF and this will therefore compromise the results. Then you've got to contend with the fact some TIM needs time to "cure" - and this can be days and/or weeks. It's tricky, and we'd rather not present test results just for the purposes of having some numbers in the article - if results are being used, we want to be sure they're 100% accurate.
     
  20. SiG

    SiG New Member

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    Funny, I was just thinking about something along these lines earlier today. While it may not relate to the 'usual' way of allowing better (and more effective) contact between the CPU and heatsink, I am curious to find out if a more 'permanent' thermal interface will yield greater results.
    Basically, if one were to create a permanent bond between the heatsink and CPU with a 'thermally acceptable substance' if they would be much better off. I was thinking of something along the lines to something akin to 'copper-solder' in that you would apply the said substance and bond the two surfaces together. Obviously heat could be a potential issue since you could exceed the suggested temperatures for the CPU before you even turn it on (I'm not too sure on the validity of this, it's just personal conjecture).
    While this solution/option is very much going to completely remove any chance of swapping heatsinks or processors independently of each other, it will solve various long-term issues that regular TIMs have (the aforementioned issues with drying/cracking, 'leakage' and so forth as mentioned in the article).

    ... I've probably ended up rambling and seeming rather incoherent and I apologise in advance if I do, I just wanted to be able to regurgitate my 'thermally-related-ponderings' before they left my mind completely.
     
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