would like more info on Lathing, Sanding, Smoothing CPU's

[Daveb2012]

what kind of grit sand paper is recommended for lathing a socket 939 AMD, say opteron 148. I am going to try this to see if it helps drop a couple degrees once my new processor gets here. I have basic knowledge on how to do this, just was wondering of some where I could read good info about it, enough to get me started comfortably. thanks in advance.

[nn_step]

Equipment Needed
• Heat sink
• Sandpaper

o 400 Grit Super Fine Wet/Dry
o 600 Grit Ultra Fine Wet/Dry
o 800 Grit Ultra Fine Wet/Dry
o 1000 Grit Ultra Fine Wet/Dry
o 1500 Grit Mirror Fine Wet/Dry
o 2000 Grit Mirror Fine Wet/Dry
• Flat surface
• Water
• Hand Dishwashing Liquid
• Time
• Beverage of choice – Beer, Bawls, Coke, or whatever

The sandpaper was more difficult to find that I thought it would be. In the end, I managed to find it at Napa Auto Parts and Wall-Mart. It comes in pack of four or five and cost about $3.00.

For a flat surface, most people suggest using a piece of glass or a glass top table. I didn’t happen to have any extra sheets of glass lying around, so I ended up using a sink counter top. This worked well for me, as two other needed items were close at hand: water and hand dishwashing liquid.

Time is also a very important item in the lapping process. Lapping can be done in as little as 30 minutes, but for better results it tends to take close to two hours. You will want to work slow and steady to make sure you do it correctly; otherwise you may end up with a heat sink that is worse off than when you started.

The cold beverage is a must. At least for me. I’ve yet to do a mod or build a computer without something cold to drink.

The Process
You will start out with the most coarse grit first (400 Grit), and repeat the process for each higher grit.

Completely soak the sandpaper under some running water, and then place it on your flat surface. I left a bit of standing water on my sandpaper. You can use hot water or cold water, it doesn’t matter. I used cool, as I didn’t want warm water on my hands to defrost my icy mug.

Next place a drop of the dishwashing liquid onto the heat sink's base. You only need to do this on the part that we will be lapping. Now, spread the dishwashing liquid around so it covers the base, again, you only need to worry about the part that we will be lapping.

Place the heat sink on the wet sandpaper. Hold the heat sink by the side, and slowly move the heat sink up and down the paper. Be careful not to apply any pressure to the heat sink, we want its own weight to do the work for us.

After about ten passes across the sandpaper, rotate the heat sink 90° (that's a quarter of a turn) and continue to sand until you've made a complete rotation. I continue to do this until I've made 10 complete rotations, stopping every couple of rotations to rewet the sand paper, and reapply the soap.

Repeat the process using the 600, 800, 1000, 1500, and 2000 grit sand paper. In the end, you will have a nice, mirror like reflection on the heat sink base.

Congratulations, you've just lapped your heat sink and created a better surface for heat transfer.

[z-design]

PROCESSORS, not heatsinks

[manomanx2]

I don't believe you can get away with sanding your processor without permanant and horrific damage. Sadly.

I think? I'm not very sure.

[nn_step]

It is the same process... you just need to learn how to hold it

[Daveb2012]

nm thanks man good write up. Ok to double check the wet sand paper is going to be laying flat on glass table rough side up, and im going to rub the top of the cpu across this paper in the way you describe (pin side up) how important is it to keep the cpu dry? I think i got it though, are they are good kits out their to sand with that have all the papers?

[wildc4rd]

I am interested in lapping my IHS as well, as I don't trust the AMD 2 point mounting enough to take the IHS off. What is the best way to hold it while lapping?

[nn_step]

The CPU can get wet but you must wait atleast a day or two for it to dry out...
As for the BEST way to hold it.. Take that Cheap plastic holder that is came in with the ESD Sponge on the bottom, Trim the the outer edge so that there are two tabs.. Insert the Proc into it.. and use the tabs to hold it level onto the paper...

[craig588]

Don't lathe a processor, ever.

[Daveb2012]

Don't lathe a processor, ever.

please elaborate

[nn_step]

Don't lathe a processor, ever.

Do you mean Lathe as in cut or as in lather.. which can be cleaned off safely

[craig588]

Lathe as in put it on a lathe. There's no good that could come out of that. Even if you did come up with a jig for it, the surface would be round, not flat.

[[XC] leviathan18]

if you want perfect mirror finish search for the laping the big typhoon thread and buy the rubing compound i posted in that thread

[mad mikee]

AFTER I TAKE OFF THE IHS.
AMD make the processors convex, part of the manufacturing process

Sandpaper turns the edges too much

Look for:
2-3" square flat 1/4" thick glass.
small rubber sheet to hold glass in place.

(*Got below from Salem distributing Co. a few years ago, will prollly last 10 more years (and no I'm not sharing, go get it direct )

2 micron calcined alumina to flatten

.6 micron zirconium oxide (in water already)

No soap since it screws up the vicosity (strange but true).

Rinse off glass and leave some moisture to mix w/ abrasive, pinhead amt of abrasive, should be completely soaked paste b4 CPU is placed on it.

I start with 2 micron & 2 fingers on either side of center back, 10 passes or swirls as the mood and resistance strikes me, rotate 1/8 or 45 degrees, repeat until 1 full turn (use the gold triangle on the bottom as a guide). LIGHTLY, you shouldn't be pressing hard enough to bend pins EVER.

You will see circular abraded area in the center that expands outward as you do this, adjust fingers as needed to keep circle centered on chip. Change abrasive/water every 1-2 full rotations. Water changes white -> grey as chip is abraded.

I usually go out 95% (1-2 mm triangle left in the corners), then switch to the .6 micron zirconium oxide to smooth and get most of the scratches out.

Right now I am typing on an opty 170 doing 2xD2OL, 270x10 , WC. Temp is 31c in 23c room. On air I get about 38-40c under same conditions of load/ ambient (x2s in wife's puter(10x250 and 'Indabst (10x270) .)

Been careful, never had a CPU fail from this (10+ cpus).





Sorry, when finished was WAY too reflective.

[nn_step]

thats extreme, I only lap the IHS

[mad mikee]

thats extreme, I only lap the IHS

Other (old) hobby: making telescopes/optics

and snapped pic of older x2 3800, (going into basement puter for testing )

[STEvil]

IMPORTANT NOTE:

DO NOT LATHE CPU'S!!!!!


Lapping is fine if you can do it right, but putting a CPU in a clamp and spinning it while a cutter strips away the surface just doesnt.. cut it


This is a lathe, dont use it on a cpu! http://images.google.ca/images?hl=en...ch&sa=N&tab=wi

[perkam]

Wow Mikee, that is xtremely accurate !!!

Wanting to get 2.8 24/7 out of it for some 400/day action ???

Perkam

[WeStSiDePLaYa]

that x2 looks pretty chipped up.

[mad mikee]

that x2 looks pretty chipped up.

Most is ceramique, but did a slight oops on mounting w / hyper6 right after I got it. Still works fine (well as good as it ever did @ least (2.5-2.6 Ghz dual prime stable )

[[XC] leviathan18]

Most is ceramique, but did a slight oops on mounting w / hyper6 right after I got it. Still works fine (well as good as it ever did @ least (2.5-2.6 Ghz dual prime stable )

wow i need that to finish my TT BT please could you tell me a generic place where to find those things to sand my big typhoon looks beatiful your core

[kemist]

Mad mikee, where did you get the stuff needed to lap the proc, id like to try it some time.

[Fr3ak]

omg that is truely xtreme
And I thought lapping my NB was xtreme
Great stuff! Gotta try it when I am brave enough to do so

[jamiet757]

what kinds of temp decreases can you guys get by lapping the die, the IHS, and your heatsink?