Hoping to squeeze that bit more out of the overclock on your Core 2 Duo (or other LGA775 based) CPU without throwing even more extreme cooling at it? Legit Reviews have kindly written up an article which shows you how, this by means of lapping the integrated heat spreader on the chip for a more even surface.
However Its a bit of a shame that they pushed their luck when attempting to remove the heatspreader altogether (for the purpose of direct contact of the cooling solution used onto the core itself). They killed their E6700 :( - Strongly advised to stick with lapping only me thinks.
If you've maxed out your processor by overclocking and want to squeeze more out of it or are just looking to reduce core temperatures lapping the processor might be something worth looking into. All Intel LGA775 processors use the FC-LGA4 package, which means that the processor die is on top of the substrate on the opposite side from the LAND contacts. This package consists of a processor core mounted on a substrate land-carrier. An integrated Heat Spreader (IHS) is attached to the package substrate and core and serves as the mating surface for the processor component thermal solution such as a heat sink. Intel actually solders the IHS to the core of the processor, so the contact on the processor is usually not of concern. This brings us to the situation on hand. Many of the Allendale and Conroe processors that we have lapped have had heat spreaders that were not flat.