Pro/Forums - View Single Post - Making CU -and AL shiny. How?!

Cathar · 10-14-2002, 08:36 AM

I second Bill here.

CPU die are extremely flat.

The only exceptions were the P3's, but it wasn't the die itself that wasn't flat, the FCPGA P3 dies had a protective thermal interface coating on the die that was not flat. Very careful grinding with 1200grit sandpaper took that coating off to reveal the flat silicon die and a small gain as a result.

AMD CPU dies are flatter (with the exception of the etching) than anything you'll achieve through lapping. Lapping to remove the etching will just result in a "crowned" non-flat CPU core that will overall have less direct surface area contact with a copper plate than with the etching left intact.

10-14-2002, 08:36 AM	#29
Cathar Thermophile Join Date: Sep 2002 Location: Melbourne, Australia Posts: 2,538	I second Bill here. CPU die are extremely flat. The only exceptions were the P3's, but it wasn't the die itself that wasn't flat, the FCPGA P3 dies had a protective thermal interface coating on the die that was not flat. Very careful grinding with 1200grit sandpaper took that coating off to reveal the flat silicon die and a small gain as a result. AMD CPU dies are flatter (with the exception of the etching) than anything you'll achieve through lapping. Lapping to remove the etching will just result in a "crowned" non-flat CPU core that will overall have less direct surface area contact with a copper plate than with the etching left intact.