about lapping my P4 2.6C cpu

[kgs]

about lapping my P4 2.6C cpu (its attached metal enclosure to be exact)

I have read a half dozen articles about cpu lapping, and because nearly all of them say you can drop cpu temp by 5 deg Celcius, it seems like the thing to do. That is, I believe, if it is simple to achieve an effective result, and I suggest that it is, and a proper/recommended procedure is followed, if you want to do it, why not, the result is beneficial. I am assuming the following:

please indicate right/wrong/missing info (on every detail please) - I am tired of pointing out where I may myself be ignorant: or more or less, just go ahead and get that 5 deg. C out?

I have:
400 grit wet/dry sandpaper
600 grit wet/dry sandpaper
1000 grit wet/dry sandpaper
1500 grit wet/dry sandpaper
2000 grit wet/dry sandpaper
3m rubbing compound ("Fine Cut....Safely and effectively removes 1500 grit or finer scratches")

First I will photocopy the printed information on the outer surface of the attached metal enclosure with my Lexmark 5150 MFD. I hope this will not damage the encased cpu. Someone else did this to show the effects of the the various abrasive steps. Could it hurt?

Then I will pull out my sheet of glass. What makes me sick about this procedure at this point is this. I have several pieces of glass: some are thick and beveled, but quite old; some much never and thinner; some are mirrors; and I could even possibly purchase a brand-new mirror or two for showing off the complete pc mod I am undergoing from behind and below. I have heard that glass flows. Do I need to be at all wary of this fact?

I plan to use water and the green dishwashing liquid (Palmolive?); but not oil, because it is designed not to burn off, and may seriously affect the mating surfaces ability to transfer heat. Please comment if this is true also of the usage of any dishwashing liquid (i.e. should I just use water). The dishwashing liquid may offer a lubricating property?

Should I skip the 400 grit wet/dry sandpaper because it may be too coarse.

What pattern of hand/chip movement should I follow? diagonal, circular, random, linear?

The rubbing compound is itself a liquid solute\solution or suspension, or whatever, and therefore may not desirable to use. I wanted a bottle anyways, but the impetus was that I have seen cpu lapping kits sold at specailty computer stores which include a rubbing compound, and the fine sand papers. I cannot say what type of compound is included. My own bottle's directions are for paint, and it says to use a clean, soft, cotton terry cloth. It does not say anything about adding water to the cloth. It says to apply in a firm, circular motion, by hand. I have no idea about whether to modify the cloth type, or whether to try to place it on the flat surface, of if ther abrasive action is so minimal that I can use my fingers.

I plan on holding the chip with by embedding it into a small piece of sytrofoam-like sheet. I have a few thicknesses and colours of possibly differning materials. I'm not sure if what I have is safe, only because I have read to use a non-conducting (or whatever type). I don't know if I can even puncture the stuff with the pins yet. I just garbage -picked the stuff. Should I get a specific style/material/thickness?

May I even grasp the thing with bare fingers?

I have no idea if I should use a cleaner to clean the surface after using the rubbing compound, or for that matter after the paper and water, or paper/water/dishwashing liquid procedure. There are a number of cleaning fluids mentioned e.g. 99% (high purity) isopropyl alcohol. Basic isopropyl alcohol is 70%. Is the high purity stuff easy to obtain, and where? Or what else is easy to obtain, and where?

Do I have to worry about crap getting around the sides, or through the alignment hole. Should I plug the hole with a dowel or something, and does it need clearance so as not to affect the san ding alignment?

The cpu cooler I buy, I understand, will not need any work, as it comes as flat as a baby's bum. Zalman CNPS 7000A-Cu only.

The stock Intel heatsink and fan will be discarded, and since the mobo will have never seen any usage without it's aftermarket final cooling solution, the thermal pad, or wax, or whatever, will never have to be removed, and ANY possible residue on the cpu's attached metal enclosure will be removed by the lapping.

Is there any potential inaccuracy caused by this procedure regarding paralellism; or clamping force required by mobo/cpu due to the amount of material removed, and the procedure?

Is it conceivable the I need to worry about actually sanding to far through the cpu's attached metal enclosure? I understand it is copper underneath.

[Apoptosis]

400 grit is way way too rough...unless you are milling a chunk of raw copper down by hand...lol

I always start out in a circular motion and then finish in the same linear direction on a flat sanding block.


As far as the dishwashing liquid may offer a lubricating property that might hinder cooling... Just clean the surface off before you use it. I use Acetone, but a "pure" form of alcohol should work fine. Carb cleaner and brake cleaner for cars works wonders, but is hard on the skin so use caution.

As far as lapping and holding the actual processor... I use an old socket that I have laying around. That way I don't damage the pins.

"Do I have to worry about crap getting around the sides, or through the alignment hole. Should I plug the hole with a dowel or something, and does it need clearance so as not to affect the san ding alignment?"

Sand away...the hole just gets filled with compound anyway... no worries here.

"Is it conceivable the I need to worry about actually sanding to far through the cpu's attached metal enclosure? I understand it is copper underneath."

You'd be sanding a long long time with sandpaper that fine to get through the cover. Again no worries.

Good luck and sandpaper away