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Introduction
I was reluctant to review a heat sink lapping kit. Why? Because it sounded like a lot of
work! I could see myself at the grindstone... er ....lapstone for several hours, moving my
arms in the arc of theta (an engineering joke). And you know what? I wasn't that far off!
Man, am I tired. I mean worn out. Wasted. Hosed. But don't jump to the end of this
review just yet. Maybe, just maybe, this is a product you need. Perhaps there is a silver
lining to this cloud...
Figure 1: Click image for a larger view
Packaging and Contents
As you can see in figure 1, you get a small package,
basically consisting of sheets of sandpaper. There are several versions of the Heat Sink
Lapping Kit, including a Premium version (which we are reviewing, shown on the left),
and a standard version (also shown in figure 1, on the right side) which we aren't
reviewing since the Premium version contains everything found in the standard version.
The folks at EasyPCKits have several other
items that are worth checking out, so please pay them a visit. The prices are very
reasonable, even for a cheapskate like myself!
Figure 2: Click image for a larger view
In figure 2, you can see what is contained in the Premium kit. Basically it's a small plate
of glass, a small container of Artic Silver Thermal compound, and one each of the 1/4
sheets of the following grit sandpapers: 400, 600, 800, 1000, 40 micron (yellow), 25
micron (green), 20 micron (blue), 15 micron (peach), and my personal favorite, 10
micron (green). The standard kit has fewer sheets of sandpaper, and no glass plate or
Artic Silver Thermal compound.
Normal Usage
Figure 3: Click image for a larger view
If you follow the included instructions, which state that they
should be read carefully before you begin (they are right), you need to slightly bevel the
four corners of your CPU heat sink (aka CPU cooler) so it won't catch and tear the
sandpaper. That was easy enough. You also need to have a bucket of water, and some
paper towels or newspaper. This is gonna get messy! But before we begin, let me
introduce you to our victim...er...volunteer, the Kanie Hedgehog Type-W Socket A all
copper CPU heat sink (figure 3).
Figure 4: Click image for a larger view
Prior to lapping, lets see how nice the stock finish is on the Kanie CPU heat sink by
looking at a reflection of my spousal unit. Note how nice the reflection is. We shall label
this intial spousal reflection factor (srf) assessment with 0.8 as a baseline. A 1.0 would
be a mirror finish, and a 0.5 would be a measure of my clear conscience. Maybe I should
be leaving well enough alone...
I use a little muscle to get what I need:
Now for the part I dreaded; sanding the
CPU heat sink with progressively finer-grit sandpaper until my arm was ready to fall off.
It may not seem difficult for you to sand something for five minutes, but it is particularily
stressful for me due to an old motorcycle injury to my right wrist - it was basically
shattered back in 1983. I have about 45 degrees of movement and daily low-level pain in
this wrist, so anything that stresses the joint (heavy lifting, applying pressure, etc.) will
generate mid-level pain for a few days. But hey, enough about my problems! That's
what the forums are for.
Figure 5: Click image for a larger view
As you can see in figure 5, I've performed some extensive sanding with the 400 grit
sandpaper. You simply must use water (wet sanding), as your CPU heat sink will catch
and tear the paper if it's dry. But I see a problem here; do you? Yep, the surface wasn't
flat. That is why the Premium lapping kit is a very good idea, if you have decided to lap
your CPU heat sink. The small plate of glass included with the Premium Heat Sink
Lapping Kit is a very flat surface, and as you start sanding with this glass as your support
for the sandpaper, it will reveal how flat the bottom of your CPU heat sink really is.
Apparently, my Kanie Hedgehog Type-W heat sink wasn't very flat at all. Keep an eye
on that center area as we progress to finer-grit sandpapers...
Figure 6: Click image for a larger view
With figure 6, you can see that time has elapsed, and now we see the result of about 35
minutes of wet sanding. We have moved up to 1000 grit sandpaper, but that center area
is still not right. Did I do something wrong? Yes I did; thanks for asking! I should have
kept going with the 400 grit sandpaper. I should have sanded until the whole surface was
identical in texture. But I couldn't do it. I was simply too exhausted after 25 minutes
with 400 grit. I bet you could do better. In fact, I challenge you to do better...
Is it done yet?
Figure 7: Click image for a larger view
One problem that requires experience to resolve is knowing when
you have sanded enough to move on to the next grit. In figure 7, we are up to 25 microns
(0.025) sandpaper, and two things are now apparent. First, that center section isn't going
to look like the outside edges unless I go back to 400 grit sandpaper for a return
engagement (I don't think so....). Second, the quality of these pieces of sandpaper is very
good - consistent abrasion qualities, and they last a good long time. The Energizer
Bunny could learn a thing or two from EasyPCKits .
Figure 8: Click image for a larger view
Ok, figure 8 shows you the best I could do, after finishing up with 10 micron sandpaper.
The spousal reflection factor (srf) is worse than what I began with. I would say we have
dropped down to a 0.6 assessment. As a result, I won't be mounting this heat sink on my
wife's computer! Also, we all know how copper will oxidize over time. I don't know if
the previous surface (prior to sanding) was coated with anyting to prevent oxidation, but
we now know that there is no longer any coating there to prevent possible oxidation.
Time will tell if this is an issue.
Conclusion
I've only scratched the surface (I've been waiting to say that) of how
far you can go with the Premium Heat Sink Lapping Kit. I didn't go far enough, and I'm
the first to admit it. I now have a much flatter surface where the heat sink meets the CPU
die, but I messed up the smoothness of that surface (as measured by reflectivity) because
I ran out of steam with the 400 grit sandpaper. Would I use the heat sink again? Yes, as
quality thermal interface compound, such as the small tube of Artic Silver that EasyPCKits included with the Premium kit,
will fill those small voids in the surface. Because the heat sink is now flatter, I might
even get better contact across the CPU die surface. The larger the CPU die, the more
likely the contact between heat sink and die has increased. But a shiny surface is the
desired outcome, so please learn from my experience and take a day or two off so you
can finish the job after getting some rest.
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