Hows my lapped CPU?

[LOUISSSSS]

http://s47.photobucket.com/alb...ew&current=lapped3.jpg

http://s47.photobucket.com/alb...ew&current=lapped2.jpg

hows that for a first timer?

found a flat metal ruler, got some 1000grit sandpaper and went back and fourth for a while rotating 90 degrees after every 2-3 slides.

how'd i do?

i know i should've started with something like 800grit but they didn't have and onl had 600, then 1000 and up. so i just got 1 sheet of 1000 lol.

i googled and sites said i needed some sort of oil (what kind/?), water, and anti static foam (wtheck is that for?)

 

[Idontcare]

Looks pretty good. I bet that took a while doing it all at 1000 grit!

The oil (some recommend dishsoap, others simply water) is more to increase the lifespan of the sandpaper than having anything to do with the quality of the finished product (your polished IHS).

The liquid (whatever you choose to use) is there to reduce sandpaper "loadings"...basically all that metal you are scraping off has to go somewhere, and when you "dry" sand it tends to accumulate between the sandpaper particles...making the sandpaper's effective grit slowly increase the more you use it which in turn makes your job of polishing take longer and longer.

Loadings has another side-benefit to us lappers though...as it raises the effective grit rating of the paper, you start polishing with 1000 grit in your case but you probably finished with 2000 grit paper...meaning your IHS is far shinier than it would have been had you not tortured your sandpaper by not using a liquid on it.

 

[Ika]

Looks a little bit rough, but it shouldn't be a big problem if it's flat. You probably could've started with the 600 grit; I started my lapping process with 300 grit. Then again, I was going for a perfect mirror finish...

I think some lapping guides recommend swapping out the sandpaper every so often, but I'm not sure if this is necessary.

EDIT: one thought... is it just me, or do you still have the nickel coating on your IHS? Lapping should reveal a uniform copper surface of both your IHS and your heatsink.

 

[Idontcare]

Louisssss here is what I started with (my IHS and HSF fretted):

http://i272.photobucket.com/al...to_bucket/IMG_5482.jpg

Here's and example shot of what Aflac is talking about, you can see how unflat your IHS is when parts of it polish down to copper before other parts do:

http://i272.photobucket.com/al...to_bucket/IMG_5487.jpg

(my IHS was convex, the center was sticking out more so than the perimeter)

And here is what it looks like when all the nickle is removed, down to just copper:

http://i272.photobucket.com/al...to_bucket/IMG_5490.jpg

Not shiney yet, real rough:

http://i272.photobucket.com/al...to_bucket/IMG_5498.jpg

Now she is decently polished and looking more like a mirror: (not the objective, but I did a little extra just because)

http://i272.photobucket.com/al...to_bucket/IMG_5512.jpg

http://i272.photobucket.com/al...to_bucket/IMG_5506.jpg

 

[LOUISSSSS]

Originally posted by: Idontcare
Louisssss here is what I started with (my IHS and HSF fretted):

http://i272.photobucket.com/al...to_bucket/IMG_5482.jpg

Here's and example shot of what Aflac is talking about, you can see how unflat your IHS is when parts of it polish down to copper before other parts do:

http://i272.photobucket.com/al...to_bucket/IMG_5487.jpg

(my IHS was convex, the center was sticking out more so than the perimeter)

And here is what it looks like when all the nickle is removed, down to just copper:

http://i272.photobucket.com/al...to_bucket/IMG_5490.jpg

Not shiney yet, real rough:

http://i272.photobucket.com/al...to_bucket/IMG_5498.jpg

Now she is decently polished and looking more like a mirror: (not the objective, but I did a little extra just because)

http://i272.photobucket.com/al...to_bucket/IMG_5512.jpg

http://i272.photobucket.com/al...to_bucket/IMG_5506.jpg

looks like a great job, what did u use to press down on the CPU and where did u press down? and what sandpaper grits did u use and for how long each?

for me i started with 1000 grit with 1 strip and stayed on it until i took the pics.
and i used my fingers to press down on the 4 sides of the CPU. i'm afraid there might be uneven pressure due to each finger using its own strength

 

[Idontcare]

I put that black cover that comes with the CPU back onto it to protect the LGA contacts.

Then I held each corner just as you did. I lightly pushed down, you can't help but push a little.

I do each grit for long enough to eliminate the sharpie markings. I did not upload all the photos, but I actually drew a pattern on the IHS with a sharpie pen before starting each new grit.

Then I polished with the new grit: 10 full-strokes, then visual inspect to ensure even removal of the sharpie markes, then rotate 90° and polish for 10 strokes, repeat till sharpie marks were gone.

Usually took maybe 10 minutes per grit. Getting thru the 220 grit was the longest as you really got to spend some time getting all that Nickle off (if you want to anyway).

I have 6 quad chips to lap (and 5 Tuniqs plus one Vapochill LS evaporator head), and after having done the first G0 and part of the second G0 I must admit I am beginning to question my sense of judgement.

This is hard work! And my back is already aching.

By the way, both Tuniq's I have lapped thus far were rather concave. They took longer to polish than the CPU's. I could see them making them concave intentionally, as both my CPU's have been convex, and a convex IHS works best with a concave HSF. So if you polish one then you really have to polish them both.

 

[aigomorla]

polish??? [directed at idontcare]

i heard your not suposed to polish the ihs. Just wipe them clean, because the polish will add thermal interference with heat transfer and mess up the contact.

But since its coming from you... im like... errrr.... what polish is that?? because theres no way you would mess this part up.


@Louisss

I prefer to take the entire nickle plate off the IHS. That way i know i got down to the copper and its dead flat. Then you need to do a grid test. Lines verticle and horizontal and see if there is any flaw in the lines.

Thats the easiest way to determine how flat your surface is. The reflection shots are all epenis shots.


I see you did a razor test after explaining to you what it was and found out your IHS wasnt flat.

 

[Idontcare]

Originally posted by: aigomorla
polish??? [directed at idontcare]

i heard your not suposed to polish the ihs. Just wipe them clean, because the polish will add thermal interference with heat transfer and mess up the contact.

But since its coming from you... im like... errrr.... what polish is that?? because theres no way you would mess this part up.

I think we have a "lost in translation" moment here. Likely stemming from my poor choice of words.

Lapping, sanding, grinding, polishing...all mean the same thing to me in the sense that you are removing material from one thing (IHS, etc) by using another thing (sandpaper, brasso, etc).

In my case, whenever I spoke of "polishing" I am still talking about using sandpaper, just rather high grit number like 2000 or 2500. It adds a polish to the surface in that it wears out the scratches (and replaces them with ever smaller scratches of course).

I am not talking about using a chemical polish such as brasso as that would be bad precisely for all the reasons you are thinking. Although I do like to "tint" my IHS and HSF surfaces with thermal compound before I assemble them, but that is certainly not polishing either.

I really should just avoid using the word "polish" in my posts, there are too many ways to interpret it and a lot of people will get the wrong idea but won't ask for clarification. Thanks for the heads-up Aigo! My bad!

 

[LOUISSSSS]

CPU is an Intel socket 478 processor

i have a question as to where/how to apply pressure on the chip when sanding it down.

i got 600grit paper today and continuing from yesterday, i've noticed that the sides and center has been showing the copper color before the rest
kind of like this:

-----------
| ----- |
| | | |
| | | |
| ----- |
-----------

where the outline of the inner square is still nickel (not a line, but thicker) if u guys dont get it i can take a picture if i dont figure it out myself.

that is probably because i've been applying pressure to the sides and the center of the CPU (where there are no pins).

i'm afraid that this means the cpu isn't flat

 

[aigomorla]

Originally posted by: LOUISSSSS
CPU is an Intel socket 478 processor

i have a question as to where/how to apply pressure on the chip when sanding it down.

i got 600grit paper today and continuing from yesterday, i've noticed that the sides and center has been showing the copper color before the rest
kind of like this:

-----------
| ----- |
| | | |
| | | |
| ----- |
-----------

where the outline of the inner square is still nickel (not a line, but thicker) if u guys dont get it i can take a picture if i dont figure it out myself.

that is probably because i've been applying pressure to the sides and the center of the CPU (where there are no pins).

i'm afraid that this means the cpu isn't flat

thats where the styrofoam is suposed to come in :X

By poking all the pins solid on the styrofoam, it allows you to apply just enough pressure to get a nice even pass. :X