chipset heatsinks and terrible thermal paste

[TBSN]

I took off the NB/SB coolers (which are attached via heatpipe) on my Asus P5K-D.

The thermal paste has hardened I guess, and it's really difficult to get off. I'm surprised the chips haven't fried by now as they weren't very well in contact with the heatsink. I've been trying to scrape at it but I don't think I'll get a smooth surface that way. I'm starting to think it was a bad idea to do this, but if I get them better cooled maybe the board will last longer. How do I get that nasty stuff off? They've put way too much on and it's spilled over the sides of the chips too...

 

[Bartman39]

On just about any board I get I take off the HS`s and re-do the thermal compound with either AS5 or a non-conductive ceramic paste it just depends on the app... Some chips like on a 1366 board that has cooling on the VR IC`s are so small you can get it on the connections so it has to something other than AS5 or run the risk of shorting issues...

 

[TBSN]

Have you ever run into rock-hard thermal paste that was there already?

 

[ReefaMadness]

You might try a hair dryer to warm up / soften the old paste, then use a plastic putty knife or similar (old credit card) to get the bulk of it off.

Then follow up with either high-percentage rubbing alcohol, or acetone (finger nail polish remover). If you use the acetone, come back with alcohol and clean up off real good before applying the new TIM.

 

[TBSN]

Ok, I'll try the hair dryer. This stuff is a real PITA, I was just expecting some normal paste. Apparently this is called "thermal cement"

 

[Bartman39]

I have and used the acetone as ReefaM suggested and had good results... Normaly I put some on a clean basicly lint free rag and do a bit of scrubbing as it will soften the junk... Dont know the need for alcohol to finish the job but cant hurt... Acetone dries to a film free finish and is common in use for painting to clean just before paint or primer is applied to remove all oils and contaminates so it wont "fish eye"

 

[Modelworks]

There is absolutely nothing wrong with dry thermal paste. Thermal grease/paste is only liquid to make the application easier, it doesn't have anything to do with how well the paste itself works. I have worked on equipment that has paste that was applied 30 years ago and all the components are working fine. Its the material in the paste , lithium, silicon, silver, diamond, gold, that is important. Gold leaf works really well and is fairly easy to apply, but very expensive , especially now.

If the paste is hard and a dark gray or brown then what you have is thermal epoxy and you will need to be VERY careful removing it. It is epoxy based so most solvents will not work. The important thing to remember is it is bonded to the chip by chemically dissolving a tiny amount of the chips surface. It isn't a glue that is just stuck on top of the surface, it is part of the surface. Removing it too harshly can remove parts of the chip ruining the chip.

Thermal epoxy like that used by OEM's
http://solutions.3m.com/wps/portal/...lSolutions/ThermallyConductiveEpoxyAdhesives/

You can try heat and cold but realize that the temp range for thermal epoxy is about the same as the safe range for chips. If it were me I think I would get some fine grit sand paper and sand it down enough that I could attach the heat sink . At least with the sandpaper and doing it slowly with your hands you can judge how much can be removed lowering the risk.

 

[bryanl]

Be very careful with acetone since it dissolves many plastics, including the epoxy used for chip packages. If the material isn't thermal glue, as Modelworks suggests, try mixing it with some oil. Most thermal pastes are made with silicone oil, the non-silicone ones with ester oil. Waterless hand cleaner may also work.

 

[TBSN]

Thanks for all the replies. Yes, this stuff is probably an epoxy (rubbing alcohol did not help at all). I got most of it off with a razor blade and then used AS5. I may have either inadvertently broken something or made the temperatures far worse, but I won't know until I try to start it up again.

This was a bit of a mistake... Oops. We'll see...

 

[IGemini]

I haven't been a fan of the thermal epoxy they use on ASUS chips. When I first got a P5W DH the northbridge would always get to 40c which made PCProbe go nuts by default. Once I took it apart to reapply, the pad they used looked thin and uneven. Some AS5 and the temp dropped by almost 10 degrees. The P5Q Deluxe I got later looked alright, though.

 

[TBSN]

That's encouraging. I also got 40c when idle. I think if I could drop the temp a little I may be able to overclock it a bit more. I slightly bent the heatpipe between the NB and the SB which was making the SB not make very good contact, so I'm not sure if it'll work right. I might have to redo it if it's not hot to the touch (meaning it's not working). Haven't started it up yet so I don't know.