Lapping my CPU & HSF

[itshondo]

I've been working on getting the temps down on my Q9550, so I decided today that I'd lapp the CPU and the base of my HSF. I also thought I'd document how I did it.

First I used a piece of glass as the lapping area. I taped it's corners to the table -



Then I tape the corners of the sandpaper to the glass, making sure that it is flat & taught -



My plans for lapping will be in 4 grit stages - 220, 320, 600 & 1500.

Now I needed to mount my 9550 to a piece of foam. This will do 2 things -

- provide a nice base to grasp the cpu,
- protect the bottom of the cpu from the metal removed from the cpu's heatspreader.

Here's the foam & cpu -



Sitting on the foam with the edges carefully taped to keep the 2 pieces together -



My cpu's Identification, pre lapping -

The HSF had been previously lapped but this raw cpu put corner indentations into the base -



I used the "Figure 8" method to lapp the cpu on WET sandpaper. I sprinkle & spread a little bit of water on the paper to help lubricate the paper & prevent metal dust from getting airbourne.

After the 220 grit -



the 320 -

 

[itshondo]

the 600 -



and the 1500 -



And a "screen shot" -




Not quite a mirror finish but a VERY flat & smooth one that will ensure that maximum heat will be transfered to the HSF.

 

[iwan]

Good job, it looks great.

 

[Porvalsh]

Nice.

What made you decide to go with the figure 8 rather than single direction and then rotation?

What were your results?

 

[itshondo]

Nice.

What made you decide to go with the figure 8 rather than single direction and then rotation?

What were your results?

I remember reading somewhere that using a figure 8 motion will stop you from rounding over the edge - what happens when a circular motion is used.

I've also used a straight drag motion on HSFs that seems to work ok, though it is tedious.

My temps dropped about 2-3 degrees C.