Arctic Silver Adhesive Question

[JRNioa]

Does anyone know the best way to remove a LED from the heat sink when it has been attached via AS Adhesive? I need to replace the LED. Any suggestions? Thank you!

 

[Ra]

Hi JRNioa,

I not yet have had the oppertunity to test it: My adhesives will arrive in a week or so..

But I can tell you this: Most adhesives weaken at higher temperatures, and Led's can withstand temps up to 170 degrees centigrade..(for short periods of time)

So you can try boiling water to heat the heatsink and gently try to break free the led with a screwdriver.. The boiling water is to prevent the temperature to rise above 100 degrees centigrade..

But if you want to go into the dangerzone: Most adhesives break down at 150 degrees or higher. (one of the exeptions is mastic silicone..)


Hope this helps..


Regards,

Ra.

 

[chimo]

Good advice from Ra. I have removed many emitters attached with epoxy by heating the assembly. This substantially weakens the bond and the emitter should come off with minimal force.

 

[JRNioa]

I heard the opposite....putting in the freezer for 12 hours and breaking the LED off.....anyone hear of this? Thanks

 

[Ra]

I heard the opposite....putting in the freezer for 12 hours and breaking the LED off.....anyone hear of this? Thanks

That could only work if there is a significant difference in thermal expansion between led-slug and heatsink..

Better heat things up..

EDIT: Try to get a 0.08mm thick rasor-blade: After heating gently push the sharp side of the blade exactly between the heatsink a the slug (If possible)
That way you apply the most force where it shoud be, not ruining the led..


Regards,

Ra.

 

[JRNioa]

OK, the LED is fogged over so I don't care about runing it...just need it removed..maybe a plyers too!

 

[DonShock]

I have successfully removed both emitters and driver boards by prying sideways on the parts instead of trying to pry them up. There was slight crushing of the edge of the PCB on the driver board but the adhesive (Arctic Alumina, not Silver) gave up before any real damage occurred. Same thing on the LED but with even less effort since the adhesive was covering a smaller area. There was just a slight dent on the black plastic part of the LED body.

 

[PhotonFanatic]

There are chemicals that you can use, also. Not sure how healthy they are for your lungs, however.

 

[joshuwaliu]

I heard the opposite....putting in the freezer for 12 hours and breaking the LED off.....anyone hear of this? Thanks

I agree after many years spent reading computer overclocking forums. Whenever someone wanted to remove a heatsink from a CPU or RAM chip, freezing always seemed to work. To the best of my knowledge, it's a combination of the shearing from the difference in thermal expansion and the cold making AS brittle.

I also have heard it's best to put the component in a sealed plastic bag before putting it in the freezer to avoid moisture, but I don't know if sealing is the correct course of action. It seems that sealing in the warm moist air would actually increase condensation, but putting it in a unsealed bag just to prevent it from direct contact with frost will be a good idea.

 

[rivethead147]

the AS is composed of Silver, Boron Nitride, Resin, and Hardener. The resin and hardener is a polymer, haven't looked into the chemical composition of the resin and hardener but it's highly likely that you can remove it with MEK (Methyl Ethyl Ketone). MEK is used in the plastics manufacturing industry for deburing and bonding, MEK will breakdown most polymers at a moleculur level, when rinsed after application it's deburing, if left and conjoined with another plastic with similar property it adheres. since it's attached to a heatsink and the LED should be glass or glass filled polymer, MEK should breakdown the resin/hardener in the AS and remove the LED safely without force.