[DIY] Which Thermal Glue? (Advice needed)

SnotBoogie

Well-Known Member
Hey RIU

As the title suggests, a thread about thermal glue. I guess we might as well talk about reflow soldering or other alternatives if people have knowledge to share, though I personally won't be using it for this build.

I've heard Arctic Silver being widely recommended on the forums, for starters, which of their many products do you guys actually use? I want an actual glue rather than just a grease I think.

If there are any alternatives, I'd love to hear about them. especially as A.S. seems to come in 5g packs (surely this won't do many LEDs?)

And as said above, if any of you would like to post a run-down of reflow soldering, I think its something that has been missing from the forums.
 

jubiare

Active Member
2parts adhesive arctic silver. You can use it for attaching the golden dragon to the MCPCB Star. And you can glue all the starts in general to the heatsink, very good thermal dissipation indeed. See, you really, really need a tiny amount and that create higher performance.

That way, you can tap gently with a screwdriver between the Star and the heatsink, should you need to modify your array.

This tip comes from an experienced diyer, theBongMaster. And anyway looking at various alternative the figures are in his favors. There is better thermal pastes, but not better adhesives, in that case you'd want to screw down each and every star ..... heat dissipation would be even slightly better!

Reflow soldering for es. cree leds, couldn't be easier, that's my personal experience: Using a standard iron plate, upside down, You can reflow the chips onto the starts pretty easily! (Thanks to the diyers over at aquarium forums)


Good luck!
 

FranJan

Well-Known Member
I'm a one parter myself
http://www.ebay.com/itm/Thermally-Conductive-Adhesive-Glue-Thermal-Heatsink-MID-/270717024919?pt=LH_DefaultDomain_0&hash=item3f07fdfa97

I went with diamond based when I replaced the grease on my 5x60 heatsinks (Hey China, it ain't f*cking frosting :x), but for the life of me can't remember which one now. Workin fine it seems. Actually next time I'm at the computer store I'll be picking some thermal grease to redo the heatsinks on my Vipar. I'll probably go with the artificial diamond again but some folks say it's no better than normal thermal paste, but it works for me.

And I'll say it once again, some of you DIYers/smarter fellas should be working on stickies for things like how to attach different LEDs and how to reflow. Hmmm maybe there's something killing your motivation:weed:. Y'all mofos need to smoke more pure sativas :).
 
I use "deltabond". wakefield solutions makes it. We use it at work on our sysyems. We tested many different varietys and it was the best overall performance. There was some "self shimming" variety from henkel(loctite) that was close called Depend series. My two cents
 

SnotBoogie

Well-Known Member
Great stuff guys! Thanks. We should try and get a guide with pics up, I bet it's something thats easy to mess up while you get the knack. Don't really think I should do a guide with my first big project though if you catch my drift ;)
 

SnotBoogie

Well-Known Member
I use "deltabond". wakefield solutions makes it. We use it at work on our sysyems. We tested many different varietys and it was the best overall performance. There was some "self shimming" variety from henkel(loctite) that was close called Depend series. My two cents
Did you test it Vs the Arctic Silver offerings, too?

edit: crossposting another article i found on overclockers, comparing silver and diamond greases: http://www.overclockers.com/diamond-thermal-grease-testing/ be warned its super old (they were "experimental mixes" at the time apparently) but the article quotes a figure of 6x the thermal conductivity for the diamond mix.
 

stardustsailor

Well-Known Member
This thermoconductive epoxy is on of the best in the market-but way expensive .....~1.5 $/gram ... :
http://www.fischerelektronik.de/web_fischer/en_GB/heatsinks/E01.09/Thermally conductive adhesive/search.xhtml

This one is ,a way cheap, thermoconductive silicon glue(not paste ) ..
Tested & proven to be good ,when applied in really thin layer ... :
https://dx.com/p/fujik-silicone-thermal-glue-50ml-grease-like-4579


While using thermoconductive glue between led slug and PCB is not that good way as doing that with solder ,it has 2 main advantages ....
-No reflow oven needed (for soldering the slugs to pcb ..)
-If led fails ,it is way more easier to be removed and replaced with a new ,when glue was used firstplace ..

One has to take care ,for the glue layer to be very thin ( less than 0.1 mm ) ..

That is achieved if :
-small amount of glue is used per led ,spreaded evenly and then
-led is placed with the proper pressure and movements ,
so that the glue will not sit in a layer - thin film - ,
but rather fill the tiny "gaps " and anomalies of the surfaces in contact (led slug - ΜCPCΒ) ....
...
It should work as "glue",stabilising the led on the pcb ,bonded at sideways of led case ..
So ,when leds pressed uppon the pcb ,do not whipe the glue-in excess- that is left over ,around the case of the led ....

gluing leds.jpg

Yes leds have to be placed ,with pressure applied ..
And some circular motion so ,for the excess glue,to come off sideways ...

This can be done by using a special plastic adapter for the leds (used also while soldering the leds ,to apply pressure ..)...
-Difficult to find... -


Or carefully by a pair of tweezers ..

Or even by hand ( better wearing antistatic gloves and bracelet ),
if there's enough expierence gained..

DO NOT APPLY PRESSURE ON LED'S LENS .ONLY AT CASE .
 

SnotBoogie

Well-Known Member
Exactly the info I am looking for SDS, great post.

I'm actually using the FUJIK stuff at the moment for some cheap cloning/veg panels. It seems fine and the tube is fucking huge. Didn't want to bring down my big panel with cheap glue though.
 

stardustsailor

Well-Known Member
Ok ...
Here's some tips :

P1095849.JPG
Apply a TINY amount of glue (Fujik is used ) ...



P1095850.JPG
Spread it with a i.e. toothpick ,evenly .....



P1095848.JPG
If you work with tweezers ,always apply pressure downwards , at "ledge" of case ....



P1095851.JPG
If you go by hand ,circular movements,for the excess glue to come off sideways ....
Apply pressure downwards at the corners -of case "ledge"-....



P1095852.JPG
Work steady ,not in a hurry ..
Glue is thick ,and it needs about 15 -30 ' to start hardening ,at room temps ....
No...Glue at the pic hasn't hardened yet ...
It is thick enough to hold the led firmly in place ...Even if you turn the pcb ,upside down ...


P1095853.JPG

Do not wipe excess glue ..Let it be ...It stabilises the led with the pcb ,better ...

Remember : Do not let the glue set to a thin layer or film ...
Metal surfaces of slug and pcb should be in contact ..
(working by hand ,you feel the friction ,between them ... ) ..

Solder the led ,while glue is still soft ...
While soldering both contacts ,apply pressure to led ..
(donwards to pcb )
No hands this time ! Tweezers ,only !

-And always triple-check for the right polarity ....
(Is the led placed correctly at the last pic ? .....No! )
 

jubiare

Active Member
all right guys but ... really simply, you gotta look at numbers when you are choosing between them ... spending a tad more on this can be crucial .. go cheaper on other stuff but with this, having the option, go with a good one .... it's how the diode transfer the heat to the heatsink.

I would be weary of products that don't tell you numbers, conductivity etc.

Also make sure if you want it to transfer heat or/and electrical conductivity. Arctic silver 2parts adhesive doesn't conduct electricity, that's what you want for golden dragons for es.

greater than 7.5 W/m°K thermal conductivity



 

jubiare

Active Member
@franjan, well there you go, you had some tutorial there. I suppose it's laziness sometimes, at least in my case.

Or it's that certain things where already so well explained in knna's thread that one doesn't feel like recalling on it? But you are right, tutorial's should come out more easily for the community!
 

stardustsailor

Well-Known Member
..A lot has changed since Knna's days ....
World has moved on ....
Many things are not the way they used to be ....
...

Still though ,yes ,branded glues like arctic silver ,are a crucial link ,to the chain of high quality parts...


Having those glues on cheap leds ,is merely ,a waste of money ...
 

jubiare

Active Member
Yes but history can repeat itself over and over again if we are not acquainted with what's been.

I would go for a good one, even with the asian diodes .... any idea what's the numbers for that fujik? If it's decent, all good...


if it's poor, I'd be careful if I was making my own array
 

stardustsailor

Well-Known Member
Well no ..I do not know the numbers ...Can't find them anywhere ....
But still usage of it is enough to show me if it is good or it sucks ....
Well ...It is not the best out there ,but it does the job ...
(The whole panel thing is like that ... )
BTW....
I can not find any numbers for the Arctic Silver ones ....
Neither for ASTA 7G or for AATA 5G .....
Neither for their epoxies...

Numbers like :
thermal conductivity
pass resistance
R[SUB]th[/SUB]

Any link ,maybe ?
 
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