Andrew, I replaced a fan assembly on a T43p - it came with thermal grease in-place (an array of dots) for the CPU and a new thermal pad (at least that is what I would call it) that contacted the video chip. I looked in the parts listing for the now ancient T43p and I didn't find the "thermal pad" as a separate part.
The function of the grease (or pad) is to enhance the thermal transfer between the chip and the heat sink/fan assembly. Neither surface is perfectly flat and smooth so air gets between them and reduces the transfer (typically by a significant amount). The grease displaces the air, making for much better transfer. The pad typically doesn't work as well as grease but works well enough for lower power devices or those with relatively lower loading (heat flow per area). We were able to purchase the pad material as a sheet for a custom instrument. You would need to know the exact thickness you need along with the required thermal characteristics. I don't know where you would find that for the X60. I would not try your solution 2 as the grease can migrate and if it contains any conductive particles (some do) it might short something if it did migrate (it probably would migrate if it had to fill a big gap). An appropriate thickness single FLAT shim would probably work but it would need to be flat and parallel. I expect that Lenovo used a pad as it reduces the flatness and smoothness requirements on the two surfaces and might allow for a slight height error. I can't help on where to get the correct pad and you probably don't want to purchase a full sheet :-( Stuart On Jul 26, 2012, at 3:38 PM, ændrük wrote: > On Thu, Jul 26, 2012 at 12:05 PM, STeve Andre' <[email protected]> wrote: >> On 07/25/12 23:13, ændrük wrote: >>> >>> What should I use as a replacement for the factory-installed thermal >>> pad on the northbridge of a ThinkPad X60? I don't see anything >>> addressing this in the ThinkPad X60 Hardware Maintenance Manual. >>> >>> I think my options are: >>> >>> 1. a new thermal pad >>> 2. a heaping mound of thermal grease >>> 3. copper shims stuck together with thermal grease >>> >>> A new thermal pad would be ideal—but where do I get one, and do I need >>> a certain kind? Thermal grease is readily available, but using that >>> alone sounds treacherous. And copper shims sound popular among >>> overclockers, but that apparently risks damaging the CPU. What do most >>> people do after removing a ThinkPad's heat sink? >>> >>> Andrew >>> >> What are you trying to replace? "Thermal pad" isn't a term I know of, >> for thinkpads. >> >> --STeve Andre' >> > > Thanks for asking. Perhaps my problem is that I don't know the correct > term. By "thermal pad" I mean the gray, squishy square between the MCH > and the fansink. I've circled its location in red in this image: > > http://i.imgur.com/GKJFD.png > > When properly installed, the fansink comes in direct contact with the > CPU but leaves a small gap above the MCH. This gap is spanned by the > gray, squishy square. > > I originally removed the fansink in order to reapply the thermal > grease on the CPU, since the CPU has started overheating under heavy > load. The gray, squishy square didn't survive the removal of the > fansink, so I need something to replace it. > > Andrew > _______________________________________________ > Thinkpad mailing list > [email protected] > http://stderr.org/cgi-bin/mailman/listinfo/thinkpad _______________________________________________ Thinkpad mailing list [email protected] http://stderr.org/cgi-bin/mailman/listinfo/thinkpad
