LT Cooling: Copper Shim, Thermal Pad or just Paste?

pete_agreatguy · 24 Mar 2017 at 11:40

Hi all,

I need some laptop cooling advice.

Brief Description of what's happened:

My dad's Lenovo G710 laptop recently stopped working (specs and service manual link are at the end of this post).

I've diagnosed the issue to be the nvidia graphics card needs reseating (or whatever the term is).

Questions regarding cooling:

I've always removed thermal pads and just used MX-4 paste from Arctic Cooling on the CPU and GPU.

But I've been doing research and found conflicting advice saying that I should use a copper shim on top of the GPU as well as paste to aid in cooling (transfer the heat).

What are your thoughts?

Does a copper shim help or not in reducing temperatures and therefore allow a longer life of the laptop?

I've done extra research and decided to use the Gelid Solutions GC-Extreme thermal paste next instead of MX-4.

Thanks for your advice all

Dad's Laptop Specs (service manual download link PDF):

Lenovo G710 laptop: Intel i3 4000m cpu, 4GB ddr3-1600 ram, nvidia 720m gpu, kingston 240gb ssd hdd, dvd-rw, wifi and bluetooth etc.

pastymuncher · 24 Mar 2017 at 13:22

The job of a thermal pad in a laptop is not just to transfer heat. In many cases it's to bridge a gap that the heatsink wouldn't normally contact whatever it's cooling. I replaced the thermal pads in my Dell D630 laptop with copper shims and it was a good move as it helped the heatsink shift the extra heat from the upgraded cpu I fitted. While I had it apart I did the same for the graphics chips as well. I have Gelid GC Extreme on either side of the copper shims on the GPU and CLU on both sides of the shim on the CPU. You need the correct size shims so make sure you get the correct ones. If I remember right I paid around £1.99 for a pack of ten shims in different thicknesses on Ebay.

pete_agreatguy · 24 Mar 2017 at 18:30

Why was it a good move in placing copper shims with double sided paste?

Were your temperatures lower? If so, what was the difference?

pastymuncher · 24 Mar 2017 at 19:51

Because the Copper shims transfer the heat much better especially on the cpu where I used liquid metal (CLU). I don't have any before and after temps because I did the change to copper shims when I upgraded the cpu to the maximum the board could take. There is a big change in heat transfer though because the exhaust is much hotter than it used to be. I will check the temps tomorrow when I download the weeks data from my weather station.

Smffy · 25 Mar 2017 at 20:44

Pads would be advisable if only to keep everything firmly seated - don't forget it's mobile device

pastymuncher · 26 Mar 2017 at 13:24

Never had any problems with mine. Use the correct size shims and it will stay in place just as well as a thermal pad. I actually found some of my notes yesterday that compares before and after temps when I changed the cpu to the core2duo T9300 from the original T7100. By using the copper shims with CLU I got a 10-12 degree temp drop which is pretty decent considering the T9300 is faster and uses more power than the T7100.

pete_agreatguy · 26 Mar 2017 at 13:26

I went from a T7100 to a T9300. Great CPU that T9300.

What do you mean by correct size shim?

Are you talking about the surface area which covers the CPU or the thickness?

I was planning on going with a 0.8mm thickness but am unsure on the size of the surface area.

pastymuncher · 26 Mar 2017 at 18:55

Thickness. Surface area should be similar to the the thermal pad otherwise it may foul something or not give good contact.

pete_agreatguy · 26 Mar 2017 at 21:36

Wait, I'm really confused now.

I should have a thermal pad as well as a copper shim with double sided thermal paste?

VKleita · 26 Mar 2017 at 22:32

No he is saying you are replacing the thermal pad with a shim, you would never have both, the thickness would be extreme and be extremely bad insulator of heat.

pete_agreatguy · 26 Mar 2017 at 22:40

That was what I thought. I have only had MX-4 thermal paste in the past, no thermal pads.

Thank you for the clarification.

pastymuncher · 27 Mar 2017 at 10:20

I really can't see how you came to that conclusion. The thickness and size of the copper shim needs to be the same as the thermal pad it's replacing.

pete_agreatguy · 27 Mar 2017 at 11:00

I'll repeat, I replaced the thermal pad with just thermal paste. I cannot remember the thickness of it. What should I do?

pastymuncher · 27 Mar 2017 at 13:47

Search the internet with your make and model of laptop and see if anyone else has replaced the thermal pads with copper shims. Chances are that you will find a few as it's a common mod and hopefully they mention the thickness of the shims they used. Alternatively, if you have good contact between the cooler and cpu/gpu with just thermal paste (should be a very thin layer) leave it as it is and see what the temps are like. Usually taking the thermal pad out ruins the contact due to the pad also being a gap filler.

pete_agreatguy · 27 Mar 2017 at 13:51

Well, there has never been any issues with the CPU, it's just the dedicated nvidia GPU that has suffered. I'll research further and thank you again for your aid and advice

pete_agreatguy · 30 Mar 2017 at 07:55

UPDATE: The reseating did not work and therefore the laptop is totally dead. After talking with the IT engineer at the shop I took it to, he said that it's a very common problem because it was a design flaw within all models, regardless of brand. He suggested not to use copper shims but to use a good paste (non liquid). Adding that, if there is a slight gap (talking mm) to use thermal pads instead.

So, I have therefore talked with my dad and found him a replacement modern laptop (a Dell Inspiron 5759 i5 6200U). I got a good deal as got it for £280 and it's not even a year old.

I'll apply some of the GC Extreme paste mentioned above to both the GPU and CPU.

Query though; should I just apply it and let the heat spread it, or spread it manually (cautious of air holes)?

On desktops I tend to do let the heat spread the paste so advice would be much appreciated