Why no standard heatspreader on AMD

[Fabje]

On the Intel Pentium 4 Processors a heatspreader is built-in. Why doesn't AMD built a heatspreader on their processor to protect the core and, well, spread the heat. I believe it could solve some of the many heat problems that people experience with the Athlon processors.
Is there a mechanical reason for this? (e.g. If they build on a heatspreader, the growing/shrinking of the die due to temperature changes is a problem)
Or is it impossible to do this without using another socket/cooler combination, which means that the current line of coolers should be replaced by newer versions.
Or does AMD think that what they currently use is better then a built-on heatspreader.

I hope you guys can help me out with this question.

 

[MilkPowderR]

I think IHS(Integrated Heat Spreader) isn't really necessary. One of the guys here actually removed the IHS on a T-Celery 1.2Ghz and got better result with overclocking higher. IHS would be good if you don't OC much and in case the HSF goes wrong or it falls off the mobo etc.. lol. Then the IHS will take a place of temporary cooling to help keep from frying. If you intend to remove the IHS, a good HSF would be needed and insure it's always in contact with the CPU core surface. =)