Ive been following this up, I'm quite interested myself in what's going on here. Here's what i've come up with so far. Most of the cracked flip chips have been breaking on one corner, or on the edge. It also seems to be occuring not only on peltier cooled systems, but on passive cooling systems as well. Initially, the culprit was thought to be thermal stress, generated by peltiers.
Latest indications seem to be a combination of the two.
The real problem is the fact that the cache and the processor core generate heat at different rates. This problem only seems to be further excerbated by the greater temperature differential generated by peltier cooling. Well personally, I'm not going to mount any coppermines without a copper shim from now on. It's been speculated that a thermal pad might be a better solution for coppermines than thermal grease, as it allows for some flex between the two materials. Regards, Aidan Carter a.k.a.