SST-90 glue it or screw it ?

[lucca brassi]

I have a little insecurity with star SST-90 mouting.

I made some adjustable cooper heatsinks for my lights and I have noticed that SST-90 have not very clear grooves for screwing.
I think now what it is better to glue it with thermal compound glue (AS) or fix it with screws and grease it with arctic silver ?

Which way it is better ?

 

[Packhorse]

You are probably better asking this in the Homemade and Modified Flashlights forum where you will get more people who have used the SST's answering the question.

Personally I would think that a little thermal grease ( not glue) ender the star then screw it down would give the best thermal path.

 

[Codiak]

I like glueing, but the price of the SSR-90 makes me want to be able to recover them... or at least have the option. The stars have a good screw pattern.

WRT thermal transfer, compond has the advantage but I'm not sure it matters that much.

 

[lucca brassi]

I have see this theme as Packhorse suggested on Homemade & Modified Flashlights ( Dark Star" quad SST-90 Elephant II @ 9000 lumens - http://www.candlepowerforums.com/vb/showthread.php?t=267667&page=2 ) I'm sure that here was used glue.

if you look SSC P7 from DX- AluPCB ( cover full screw )

VS some other STAR ( cover 3/4 of screw )

VS SST-90 ( mine seems more open than on attached picture ( cover 2/3- 1/2 screw )

Maybe I'm more careful and slow :D (making lights ) from nature of my work , but then works without problems. Yes SST -90 are expensive :shrug:

 

[wquiles]

Packhorse and others are right - the best thermal transfer is indeed the thermal paste (not glue) and screws. However, the difference between the thermal paste and the thermal (2-part) epoxy is not that significant, so many (myself included) have been using the thermal 2-part epoxy for years - I have yet to have any come off or die with use. Then again, the SST-90 has more power than any LED most of us has used :D

There is a recent thread that has the thermal transfer data for each method. I will update this post with the link once I find it.
EDIT: Here is the link

So basically the thermal epoxy is about 100x better than air, and the better thermal paste is about 300x times better than air, but this 3x factor on an already large number is not that significant, so this is what I was saying above that the 2-part thermal epoxy is enough for most of what we do.

Will

 

[Delphinus]

I like glueing, but the price of the SSR-90 makes me want to be able to recover them... or at least have the option. The stars have a good screw pattern.

WRT thermal transfer, compond has the advantage but I'm not sure it matters that much.

It's very easy to detach an artic silver glued led with a chisel as long the surface is flat and they aren't recessed.

Finally you can clean the remaining glue with acetone, for the star I prefer to use a dremell with sand paper.

If the surface is copper for a SST-90 probably will be better to screw it.