Thermal Cement?

John Doe wrote:
"larry moe 'n curly" wrote:


Krazy Glue is a brand of super glue. It will work, but I don't
like it because sometimes the heatsink comes off all of a sudden
if knocked.

That is not the superglue that I am familiar with.

It was explained that if it comes apart at one end, it becomes very
easy to keep coming off, and this is a worse problem with super glue
than with epoxy.

While thermal epoxy may be the best stuff for this, it makes
removing the heatsink later on difficult because it sticks so
well, and it can be risky to remove it

Then don't remove it.

I was just answering somebody else

I cannot imagine why anybody would ever EVER want to remove a
functional heat sink.

To each his own...

What if you have to replace a defective chip but don't have another
heatsink?

On Sunday, July 1, 2012 8:22:58 AM UTC+10, John Doe wrote:
Paul <nospam needed.com> wrote:

> Agent_C wrote:
>> John Doe <jdoe usenetlove.invalid> wrote:

>>> If you are very familiar with using super glue, you can use
>>> that.
>>
>> Would this include 'Krazy Glue' ?

You have to do it right, the first time. Using super glue takes
some practice. Since you don't really know what it is, you might
want to exhaust other options first.

> That means Crazy Glue can be removed, but the acetone would
> likely do cosmetic damage to the IC as well.

Yes, of course you do cosmetic damage, but it doesn't matter as
long as you get it right.

> If you use methylene chloride, use in a well ventilated area

It will burn your eyes. Sometimes you can see superglue smoke
rising up from the object you are applying it to. I usually
promote ventilation, but superglue is so extremely volatile that
it doesn't stick around. The initial timeframe is what matters,
especially like when keeping yourself from getting stuck to
things.

> Crazy Glue would not be a good conductor of heat

I know I've asked before, but you really need to provide some
citations for that. And I'm not talking about somebody else's
opinion from a hardware overclocking site.

If the two pieces to be glued are flat, there will be an extremely
thin layer of superglue between them.

> so you'd want as thin a layer as possible. If you have surfaces
> that are milled flat

Yes, flat matters. You don't really have to worry about using a
thin layer, Paul, because it's going to squeeze out when you clamp
it or press on it. Sounds like you're not at all familiar with
using superglue.

And I would not recommend using a mirror smooth piece of aluminum
as the heatsink. It should be lightly sanded with fine sandpaper.

> and have a mirror-like finish, then you stand a chance of having
> a very thin glue layer.

What you're saying would take some trial and error to prove. And I
doubt that you're aware of, or have personal experience with, any
such trials.

On glass, something superglued can be snapped off. And then the
residual superglue can be scraped off with a razor blade.

The aluminum heatsink should be flat as possible and lightly
sanded with fine sandpaper, then cleaned. The chip being clean and
flat doesn't need to be sanded, because the superglue will
probably melt the surface of the chip. With enough pressure, the
melted chip surface should meld into the finely sanded heatsink
particles.

> The reason the thermal epoxy gets any mention at all, is it's
> loaded with thermally conductive particles. And if it goes on a
> little thick, it doesn't hurt anything. It still conducts heat.
> If it wasn't for the conduction properties, people wouldn't use
> it.

How much experience do you have using superglue as a heatsink
adhesive, Paul?

You keep saying to use a thin layer, but that's not important when
working with superglue, since it squeezes out with pressure. That
is, as long as you apply the pressure right after applying the
glue.


It might be very important if you want to minimise having it running out of the join when clamped and getting into places where it isn't wanted.


There's nothing wrong with superglue as a heat sink adhesive, as
long as you are skilled at using it.

If you are trolling for encouragement to actually try using
superglue as a heat sink adhesive, Paul, hopefully that helps.

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>
> Paul
>