GoKawiilWhen I was researching the mess related to strange and poorly documented CPUID bits in the Athlon MP and XP processors, I had to swap a lot of CPUs. This was uneventful in most cases… but only most.
When I removed the heatsink from one unlucky Athlon XP, the processor looked like this:
A chunk of AMD Athlon silicon is just gone
And this is what the heatsink looked like, with a piece of the CPU glued to it:
A piece of an Athlon CPU stuck to a heatsink
There are two interesting things about this. One is that the CPU worked just fine until a good chunk of it came off. The other is that removing the heatsink did not need any particularly excessive force, although some heatsinks do have a tendency to get stuck on.
Based on the shape of the “extracted” piece of silicon, I suspect there was a relatively long and straight micro-crack in the silicon which did not noticeably impact the operation. But when force was applied, the micro-crack gave way, and then a whole big chunk of silicon came off.
A close-up of the damaged CPU
Notice how the right-hand side of the gouge in the CPU is very straight, whereas the left-hand side shows typical fracture marks.
It is notable that around 2000, both Intel and AMD used flip-chip PGA packaging in an effort to provide better cooling (something both companies struggled with as the TDP of the processors quickly shot past 50W and approached 70-80W).
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