Methods of adhering an emitter to a heatsink....

Hello everyone,

I have yet another question for you guys. I have successfully removed the LS emitter from the star. *phew*

Now that that part is accomplished, I'm looking at the task of adhering the emitter onto the heatsink. I know many people use arctic silver adhesive. I'm wondering if AS is the best method? And also -- it is apparently permanent. Is this true, or is there a way around it's permanency?

[edit]Just looking at my emitter I noticed that the +/- signs were on the actual star part of the LS. How do I know which end is positive and which end is negative on this emitter?

Thanks again!

Hi there

Artic Silver Epoxy is the best IMHO. It is permanent but excess force can always dislodge it. Becareful that the lens does not come off when the force is applied in the wrong area.

There is a dot on the metal tab on one side of the emitter. That is the +'ve end, the anode.

Yes, AS epoxy is rather permanent. Supposedly it can be pre-weakened by mixing it with roughly 50% AS thermal compound. I've never tried, and I don't think it's worth the risk of damage to the LS- better to buy another than to have to replace one. (if you can follow that statement, you're doing better than I am, ATM.)

Polarity testing- grab a 1k ohm resistor (or something somewhat close) and a 9v battery- I say that one because it's above the voltage for the 1w and the 5w LS, and you didn't specify what you had. The resistor should keep the amperage perfectly safe, yet let the LS light up enough to show if it's connected right.

arctic silver is fairly permanant, depending on the mixture.

one time, i tried to remove a 5w rb off a 5d mag because i wanted to transplant it on something smaller...
i tried to rip it off with a knife, and the whole emitterexcept for the slug flew off! i likely didn't have a 50/50 ratio of the mix.
poor rb /ubbthreads/images/graemlins/frown.gif

Isn't it the pits when that happens Roth!! /ubbthreads/images/graemlins/frown.gif

yes! /ubbthreads/images/graemlins/banghead.gif /ubbthreads/images/graemlins/banghead.gif /ubbthreads/images/graemlins/banghead.gif

Thanks for the advice guys!

Hotbeam -- I do not see this dot you speak of. I ended up using the method PsychoBob mentioned, except I used 4 D batteries. This was before I read any of this so I was sweating it, hoping nothing damaging happened. *phew*
I figured out which was the anode/cathode and then taped it to a post-it with +/- marks on it hehe!

Again thanks for the advice guys -- I guess I'll place an order for some of the frickishly expensive artic silver adhesive. (Am I cheap for thinking 10 bucks plus 5 shipping is a little exorbitant for glorified glue?)

[edit]By the way Roth, sorry to hear about the mishap. That's painful just hearing about it. (*grimace*)

If no dot found on already-separated emitter, usually the side with the longer tab (not the leads, but the little tabs sticking out right next to them) is positive. Or a quick shot of electricity @6V for the 5W or 3V for the 1W will tell you the polarity without damage.

To remove Arctic'd emitters, I use a skinny wood chisel (¼" wide or so, so that you don't cut off the two desoldered wires that are usually inevitably still sticking out near the Luxeon somewhere) from the side at 90°, right at the BOTTOM of the metal slug base where it is conjoined to the heatsink. A little tap will do (just did one tonight in fact). Make sure there is a soft cloth or pillowy thing underneath as the emitter will come flying off.

Remove emitter from Star by desoldering the leads first, then grabbing opposite sides of the Star plate with two sturdy pliers. Bend each side back (away from the emitter) and it pops right off (just did this tonight also).

Arctic Silver Epoxy has tested marginally better at transferring heat, but I have been using Arctic Alumina because of three reasons:

1) it sets up more quickly, good for production work

2) it has ZERO electrical conductivity unlike Silver

3) it is about half the price of Silver.

YMMV but all of the above operations have been performed dozens of times by yours truly exactly as described.

HTH...

almost as good as AS and easily bought locally is 5 minute jb weld.i have even cheated and mounted emitters with ca (krazyglue) and they seem to hold up.3 1w whites on a chipset heatsink from a dead ecs mobo.running @450 ma and no problems

I've never had any success in trying to reclaim emitters off the heatsinks. After destroying a couple of good emitters I gave up. What I do is, I epoxy the emitter to an aluminum post( about 9mm x 5mm). So now, instead of trying to pry the emitter off I just snap the post off from the heatsink and leave the emitter untouched.

Where might I purchase some of this Arctic Alumina? My favorite computer parts stores either don't carry it or are entirely sold out with no ETA.

Try here:

http://www.sidewindercomputers.com/therinmat.html

or

http://www.svc.com/thermalgrease.html

If you want to adhere, make sure you buy the epoxy. Other wise just the plain thermal compound.

I've ordered from both places in the past and have had flawless service.

If you're in Texas, and can spot a near enough Fry's Electronics, they should have some there... Or you can go to their Outpost.com site and see if they list any... Otherwise, directly from Arctic Silver's webpage, there should be a list of dealers there that can help you out...