Applying TIM to heatsink - best practice?

[Alan_A 1,650]

A quick reality-check question...  

I'm about to start my new build (probably next weekend, still waiting for some parts to get to my doorstep), and wanted to double check the current thinking on the best way to apply TIM between the CPU and the heatsink.

Have tried to read up, and my current understanding is:

-- Apply a VERY small amount - say, the size of a grain of rice, not a pea like in the old days

-- DON'T spread the TIM by hand.  Instead, place the heatsink on the CPU, and let the pressure do the work

Do I have it right?  Please advise if there's a different/better way to do it.

Please note I'm not worried about the TIM between the CPU die and the lid.  I went for a Silicon Lottery delidded CPU - have done my own delidding in the past, but this time I wanted a guaranteed performer.  So the only issue is the TIM on top of the lid, not under it.

Thanks in advance!

 

[lownslo 592]

Howdy Alan,

To be a spreader or a dropper??  I don't think it matters much... I've been a spreader for many years, and I've never had a problem.  What matters the most to me (whether I spread or drop) is the viscosity of the TIM.  I always warm it up before application by placing the tube in hot water some time before I work with it.  That makes it so much easier to know the TIM is doing what we want... spread across the interfacing surfaces.

HTH,

Greg

[Alan_A 1,650]

Ah, interesting - wouldn't have thought of warming the TIM.  I'll be using Coollaboratory Liquid Metal Pro, which in the past has seemed pretty easy to work with, but always at room temperature.  Will think about heating it this time. Thanks!

 

[lownslo 592]

17 minutes ago, Alan_A said:

I'll be using Coollaboratory Liquid Metal Pro...

Then you shouldn't worry about the viscosity of that TIM.  I thought you would be using a paste between the IHS and CPU cooler.  Press on and keep us posted about your build!

Greg

[Alan_A 1,650]

Ah, OK, understood, wasn't sure if that was a new way of working with it.   No, I've always used it exclusively, both on my delids and on the heatsink.  So will just work with it out of the tube, like before.

Thanks again - and yes, details to follow once I get to grips with it.

 

 

[martin-w 3,235]

18 hours ago, Alan_A said:

A quick reality-check question...  

I'm about to start my new build (probably next weekend, still waiting for some parts to get to my doorstep), and wanted to double check the current thinking on the best way to apply TIM between the CPU and the heatsink.

Have tried to read up, and my current understanding is:

-- Apply a VERY small amount - say, the size of a grain of rice, not a pea like in the old days

-- DON'T spread the TIM by hand.  Instead, place the heatsink on the CPU, and let the pressure do the work

Do I have it right?  Please advise if there's a different/better way to do it.

Please note I'm not worried about the TIM between the CPU die and the lid.  I went for a Silicon Lottery delidded CPU - have done my own delidding in the past, but this time I wanted a guaranteed performer.  So the only issue is the TIM on top of the lid, not under it.

Thanks in advance!

 

 

 

If it's conventional TIM, then research has demonstrated that a small blob in the centre of the IHS, about 5mm wide, is the best. The pressure from the cooler spreads it for you. This way you avoid any possible voids etc.

If it's liquid metal TIM, like Liquid Ultra, Liquid Pro or Conductonaut, then it needs to be spread evenly across both surfaces.

 

 

[martin-w 3,235]

17 hours ago, lownslo said:

Howdy Alan,

To be a spreader or a dropper??  I don't think it matters much... I've been a spreader for many years, and I've never had a problem.  What matters the most to me (whether I spread or drop) is the viscosity of the TIM.  I always warm it up before application by placing the tube in hot water some time before I work with it.  That makes it so much easier to know the TIM is doing what we want... spread across the interfacing surfaces.

HTH,

Greg

 

You are right, it doesn't  matter "much". It matters a "little".

It's not about "having a problem". It's about optimal performance, it's about CPU temp. There won't be a huge difference between the two methods, but the blob method is easier and may drop the temp somewhat.

[lownslo 592]

1 hour ago, martin-w said:

 

You are right, it doesn't  matter "much". It matters a "little".

It's not about "having a problem". It's about optimal performance, it's about CPU temp. There won't be a huge difference between the two methods, but the blob method is easier and may drop the temp somewhat.

You apply it your way, I'll apply it mine.  In the end it's all more subjective than objective... the key is lowering the viscosity of a conventional TIM so that it might better fill the voids left by manufacturing.

[vortex681 806]

Can't resist adding to the discussions! For a demo of the different techniques, with visual results, see: https://m.youtube.com/watch?v=-hNgFNH7zhQ. I prefer the X method (1:32 in the video). I would personally avoid manually spreading the TIM as you can end up with small bubbles (I learned my lesson with that one).

 

[Alan_A 1,650]

3 hours ago, martin-w said:

If it's liquid metal TIM, like Liquid Ultra, Liquid Pro or Conductonaut, then it needs to be spread evenly across both surfaces.

Thanks.  As noted, it'll be Liquid Pro.  Just to clarify - does it need to be applied to both surfaces?  Or spread a layer evenly on the CPU lid and let the pressure from the cooler do the rest?  Sorry, am not a newbie but it's been a while, and I'm rusty, so trying to come back up to speed.

[westman 257]

both sides, be very very careful when you mount the cooler , its easy to get a bad mount with CLP or CLU

Bad mount have bigger impact on the temp then how you apply conventional Tim , my personl thought.

 

 

[mpw8679 428]

Curious to know how this turns out Alan.  Currently waiting on my delid tool and liquid ultra to arrive.  First time for me.

[Jetset408 108]

Place a bead of it on the middle of the CPU and then with cling film around your finger, dab it all over the CPU to create a smooth even layer. Voila!

[lownslo 592]

1 hour ago, vortex681 said:

For a demo of the different techniques, with visual results, see...

Interesting video... I have some questions (all rhetorical, of course).

He uses a piece of plexiglass or acrylic which he presses to show how each method "spreads" the TIM.  Why did he use a sheet of material that could flex and thus skew results?  Why not use a thicker material that would not flex?  How does he know he placed the same amount of pressure on each sample?  How does he know the pressure he exerted is evenly placed (in each example his pressure points - the finger tips - is in a different position)?

One thing we do know from his YouTube video... he made money from it. 

Again, the method of spreading conventional TIM is not nearly as important as the viscosity.  The lower the viscosity during application the better the chance the spread will be even and devoid of "bubbles/pockets".

[Alan_A 1,650]

38 minutes ago, westman said:

both sides, be very very careful when you mount the cooler , its easy to get a bad mount with CLP or CLU

Bad mount have bigger impact on the temp then how you apply conventional Tim , my personl thought.

 

 

Thanks.  Am trying to recall if I've done both surfaces in the past, or just the CPU.  Honestly don't remember.  Results have always been good, but maybe there was room for improvement.

Am going air-cooled this time - Noctua NH-D15S, which is a big animal, so I'll have to take more care with the mounting than I did with water cooling (have used both custom and AIO).

Came across this video from Coollaboratory on how to spread Liquid Metal Pro - seems familiar, though I think I did the business card method last time.  For this round, will hunt down some lint-free Q-tips.

(Almost) ready for the adventure...