What does a P4 thermal pad look like?

[coolcpu2]

I took off my hsf and found something which to me seems odd. On the bottom of the heatsink there was a metallic strip affixed to it. This isn't a thermal pad is it? It looks like just something which was left on the bottom of the heatsink.

[Ffats]

Actually, it is to help thermal transfer, so yes it is a thermal pad. Intel put it on its stock heatsinks to help, and I think it does a good job considering it is a cheap and stock solution. It should have been covered by the black thermal pad. You should remove the foil if you plan on using a different TIM.

[coolcpu2]

There was soot, but I saw nothing looking like a pad, unless the soot is the remnants of the pad. But yea, I removed the metallic strip, because I plan on applying ceramique. I don't like 64c load temps. :(

[Ffats]

Oh, from a used heatsink. Yeah, the 'soot' is the remnants of that black pad.

And 64c load temps are naughty :(

You may want to consider another heatsink or adjust your case airflow a little.

[texasfit]

Be sure to get all the black remnants of the old pad off both the sink and heat spreader before putting on the ceramique. The ceramique is thick stuff but apply it in a very thin layer.

[coolcpu2]

What would you advise using to get the remnants off? I have cleaned both the heatsink and heat spreader but both are discolored black from the pentium 4 black thermal pad.

[CrystalMethod]

I use lighter fluid, and then follow up with 99% alcohol.

[Ffats]

Acetone (Nail Polish Remover) and then a rub down of Isopropyl alcohol would also work.

[Colin]

Acetone followed by isopropyl alcohol is OK, nail polish remover is not.

Cutex, the most popular nail polish remover contains: “Acetone, Water, Propylene Carbonate, Dimethyl Glutarate, Dmethyl Succinate, Dimethyle Adipate, Glycerin, Gelatin, Fragrance, Denotonium Benzoate, D&C Yellow No. 11.”

Obviously several of the ingredients should not come into contact with a CPU, heatspreader or heatsink. Glycerin, Gelatin and the Fragrance (an oil) will leave a residue in the microscopic surface imperfections and compromise the thermal interface.

Colin Thompson
Arctic Silver, Inc.

[squirtle632]

Well I'll be a monkey's uncle. I removed my heatsink again and found I had the foil on there too... DUH. Well I removed it, cleaned it, and reapplied Nanotherm PCM+ and saw virtually NO difference in temps.

[Nanotherm]

That's because the IHS acts as "thermal equalizer", extending the surface area of the CPU and spreading out the heat like it's supposed to do. Therefore, don't expect to see any major reductions in Die Temp from one TIM to another. Besides, the built-in CPU thermal diode that is providing the temperature input is buried beneath the IHS and under a layer of adhesive, so it is really "insulated" by two thermal layers from the actual TIM itself. Once again, don't expect see much of a change if you're using the thermal diode for a temperature input sensor.