Thermal Paste, Pads & Gaps in Laps

Since folks here were kind enough to help me sort out which cpu's I could upgrade to on my laptop, I'm back for a bit more information before I begin.

I've built a few basic desktops from scratch, and recruited to put together my nephews giant psycho-gaming machine, which has a graphics card the size of my first mobo and a heat sink the size of my left shoe... lol! BUT, even though I'm excellent at precision work and can follow directions down to the serif on the edges of a 6pt T - the reasoning behind the designs isn't in my field of expertise (which is why the young gamer knows what he wants and why he wants it, and only needs me to assemble it - so nothing fries when he fires it up!)

Laptops obviously have major differences, I've taken apart 5 now just to clean them and have a look - and the thing I notice immediately is the massive gap between the cpu/gpu and their respective heatsinks. In nearly every one of my cases there is a "pad" in the laptop where I'm used to putting paste on a desktop.

What I don't know for sure is if I have to replace pads with pads when I swap procs, and if not do I have to fill the spaces with the shims I've been reading about? When I look at the designs it doesn't appear that the heatsinks would screw down snug on the chips - but there is no way paste is going to fill these gaps. And another thing, when I lift a heatsink off and the pad looks pristine except for a light impression left by the chips rectangle do I need to scrape it off or can it just go back down?

I'm asking a lot I know, but each one of these laps suffers from different levels of "mangelism" under their skins therefor I'd like to be armed so as not to be dangerous Any info on the best way to fill the gaps or links to excellent pages like that thermal paste one from the cooling thread would be greatly appreciated.

My future victims:

Compaq V2000 AMD Sempron <----- $20 waiting for a reflow!!
HP DV9000 AMD Turion 64x2 <----- gorgeous with a single fried diode
Gateway 6710 Intel T2300 <----- more mangled than not
Dell Inspiron 9300 Intel M 730 <----- the most recent and by far the most impressive design internally
Dell Inspiron 1525 Celeron M 540 <---- my first and current favourite

Cheers!

 

coppermod will do the job.. or you can try IC Diamond 7..
there's a thread where they replace their pads with only ICD7

 

Pads are crap. On my laptop I was able to bend the heatsink a bit to lay flat against the processor.

 

It really depends on the specific notebook design. Manufacturers tend to use thermal pads for simplicity reasons; almost any idiot can peel and stick. Applying thermal paste tends to be a bit more of an art. Even so, it depends on how tight the heatsink can screw onto the CPU. For example, my NX860XL that I'm typing on now came with a "pad" on the CPU that seemed to be nothing more than a little piece of foil. That's since been replaced with paste, since that little piece of foil made for a very small gap. As stated before, many people have had success with IC Diamond, which is a very, very, thick paste. Still, if it's a significant gap, you're probably better off with either a pad or a copper shim, depending on how hot you anticipate the CPU might get.

Oh, and oftentimes, you can reuse pads to a certain extent. You still might want to change them after a few years, or if you see temperatures getting too high.

 

I agree what sort of idiot would put thermal pad in a laptop?
When I see one to the bin it goes, if a gap exist I would use a copper shim if not I will just leave it.
I have tried removing thermal pad on 2 laptops.
One is mine the temp drop from idling at 65+ now it idles at 55+
The other is a relative now running Intel burn in temps never exceed 70 degrees.
Therefore I have come to the conclusion that remove thermal pad when you see one it is crap.

 

I'm using MX-3 instead of pads , working great .. even better than before I would say !

 

All mine have pads except one, it has that thin piece of foil Judicator mentioned whick looked mangled underneath when it's heatsink was lifted - wonder how the last guy managed that??

The gaps are almost as thick as dimes - I got the impression reading you weren't supposed to put paste on really thick - but like I said I've only ever done desktops so I'm used to super thin spread. Darn, I don't have easy access to copper shims here, 3 weeks snail mail...

Back to pads - at the moment I'll have to reuse since I don't have anything shim or pad to replace them with - what is their normal state supposed to be then? Soft-ish or solid? How to tell if it's "spent" so to speak.

Cheers on all the good info folks

 

Pad will degrade over time due to constant heating and cooling.
Maybe that is why they put them in the first place: so you need to buy a new laptop 2 years later because the old one "overheats" and shutdown.

 

The foil may have been stuck to the heatsink, and thus when you pulled it off, it ripped and thus got mangled.

The problem with thick paste is... that it really depends on the paste. Some pastes are more "runny" and thus won't stick to themselves well. These kinds of pastes don't work well in a thick layer because they'll flow out, and leave air gaps. IC Diamond, for a specific example, is rather thick, and adheres to itself quite nicely, which makes it, if not ideal, at least usable for thicker gaps.

Pads... depends on what they're made of. Many, I think, are made of a wax-like material, so they should probably seem maybe slightly rubbery, but pretty much solid. As for spent... it's hard to say. Most pads are designed to melt slightly at the contact surfaces to achieve better contact with the component/heatsink and eliminate the air gap.

 

Thermal paste is not designed to fill a wide gap. If the gap is as thick as a dime, you are better off copper modding, as in buying the proper thickness copper shim to bridge the gap. Than use your thermal paste and your done.

Bending the heatsink or attempting to bridge a thick gap with thermal paste is not good practice. Replacing the thermal pad with a new one, or bridging the gap with copper are your only options.

K-TRON

 

but they're getting good results with ICD7 http://forum.notebookreview.com/showthread.php?t=372333

but it's true that ICD7's nature is abit different than other paste, it's meant to be thick in usage.

 

This sounds exactly right - it looks like a chunck ripped from the center.

The pads all seem a little spongy, as a matter of fact the first time I saw one I thought what an odd thing to use since sponge is an insulator not a conductor... But once I got online and read pads were common in laptops I just assumed it wasn't sponge, just spon-gee.

One of the graphic chips has a pinkish pad which had two flecks of blue glitter on it - that was bizarre, I figure a fashionista must have tinkered with it before I adopted it :laugh:

I'm going to go the shim route I think, I'm having a hard time finding anyone here who sells the newer thermal pastes. Best I have located is Arctic Silver 5, which is good stuff but not so much for the big gaps on it's own.

 

Still copper mod is better...

I've once replaced the northbridge thermal pad in my Studio 1735 only with Innovation Cooling Diamond because of that thread (but I forgot where I put the stock cooling temperatures reading, so I didn't know how good it was). After I've managed to get the proper copper shim and installed it in, there are temperatures differences of 10 °C between using only IC Diamond and using IC Diamond with copper.

See this link:
http://forum.notebookreview.com/showthread.php?p=5843558

 

Why? Bending the heatsink gives better results than bridging it with copper could. The copper shim and two layers of thermal paste has a lot more thermal resistance than one layer of thermal paste does.

 

Because you are advising people to bend there heatsink, ultimately destroying it. Then you preach that a bent unit will still work as efficiently as one which was designed to sit flat in both the laptop, and ontop of the processor. The flatter the heatsink is the better, bending it will only be detrimental.

K-TRON

 

Bending the heatsink is not a very good idea since the adjustment must be exact, and that is difficult to achieve by bending a piece of metal. Furthermore, the heat pipe is usually made of very malleable metal (such as copper) that can easily just break.

 

Um, no. It actually works, and it works well. Nothing is destroyed, contact is excellent, and its cooling ability is better than shimming it.

Of course you wouldn't know, but are still willing to bash it.

 

Second of all, it is very easy to do with some needle nose pliers. The amount of bending is very minimal, just two tiny bends, enough to bridge only a 1-2mm gap. You can't open the heatpipe with that kind of work unless you are totally incompetent. It can get very close on the first try and takes very little work to make it lay evenly as evidenced by the spread of thermal paste.

 

Careful, K-TRON. I don't want to be the one to say you're a hypocrite, but if the shoe fits...

In any case, how is bending a heatsink ultimately destroying it? As long as the metal is malleable enough, (such as copper), then there is no detrimental effect to the metal from doing so. Thermal conductivity, however, may be a different story (as you rightly pointed out).