thermal paste and pads

[VeskoGeo]

           Hello, I write here because I couldn't find anything on the subject in the manual, at  least it says thermal material which can mean thermal paste  but also thermal pads. If I open the HP Probook 450 G1 to clean him from the dust, change the thermal paste on the processor unit, do i need to buy for the  GPU thermal pad and if i need pads and not only paste, what size exactly ( how thin - 0.5 mm, 1mm ar even 2mm)? Thank you in advance for your help. It's always nice to have a professional guides you a little in those specific areas.

[Huffer · Accepted solution]

Over the CPU and under the heatsink, anywhere it is metal to metal, you will install thermal paste. Over the video and possibly the main I/O chip you will generally have thermal "pads" which are made of a compound  kind of like stiff silly putty. On some models there is even a thermal "pad" over the CPU. If you are careful with those you can simply reuse them. Do not put thermal paste on them. When the manual speaks of thermal "material" it means the pads. When you remove the heatsink it will be obvious where it is metal to metal and where it is a pad. Metal to metal contact points need to be cleaned and have new compound applied. Pad points just need to be kept intact and reinstalled.

Personally when I am rebuilding a laptop I do not like those thermal pads and I remove the pads and use copper shim material and you have to sometimes use more than one shim to make the heatsink have just the right connection. It has to make good contact, but not deform the heatsink. But if you use the copper shims you need to use thermal compound (such as Arctic Silver) on the touchpoints above and below the shims. Cooling performance is much better with shims. 

If this is "the Answer" please click "Accept as Solution" to help others find it. 

[VeskoGeo]

        Thank you for your detailed answer on the process of rebuilding a laptop. I too considered putting  copper shims instead of thermal pads, because of their significantly better thermal conductivity. But when I searched to buy, it appeared they possess different sizes. For example: 15x15mm but different width: 0.5mm, 0,8mm, 1mm, 2mm  or 10x10mm and different width( 0.5mm, 0,8mm, 1mm, 2mm). Same goes for the thermal pads, but there the size doesn't matter as much as I suppose you can cut the exact size you need, but the width problem remains. Probably putting 2 pads on top of each other will decrease even more the thermal conductivity. And that goes for copper pads too even with the mandatory thermal paste between them. So my initial idea in posting my first comment was to be told also the exact gaps in between for HP Probook 450 G1 if that is a know fact and they don't fluctuate for each piece sold of the model. I hope I explained myself better this time. Best Regards!  

[VeskoGeo]

Thank you for your answer too! Putting only thermal paste instead of a thermal pads will probably work better for thin gaps like 0,5mm or maybe even 1 mm, but if the gap is bigger probably air bubbles will be created in the paste which from what I read is counter productive. But I agree with you that thermal paste has a better conductivity than the pads, so maybe if the spaces are thin I'll use you method. Putting a dime serves the same purpose as putting copper shims so no need to discuss any further this method, but I reckon it's a saving time idea. Best Regards!