Thermal Paste TIM application Stencil Template for COBS

[robincnn]

Source
http://www.bridgelux.com/sites/default/files/resource_media/AN30-Thermal-Management-of-Vero-LED-Modules.pdf



Read This thread for some info on TIM.
Thermal Paste as TIM & Cree CXA30x0

Low power cobs do not have much heat so TIM consistency is not a major concern.
Also with smaller cobs you have less chances air pockets due to bad TIM application.

However with bigger COBs you want to apply an even layer of TIM.
An average DIY should not have much concern. Looks like almost everyone here does a good job with TIM application.

Why use a Stencil/Template for TIM application ?
There are some of us who want to apply a perfect layer of TIM. Some are not sure how much to use.
Also there is commercial use. When you buy a commercial lamp you do not want excess TIM oozing on sides. In commercial you want to consistent and fast application of TIM.



How to make a Stencil Template ?
Open attachment. It is good for 3590 and 3070 with Ideal Holder and Vero 29
Go to local Staples or office depot store. Email them this attachment and ask them to print on a 'Transparency Sheet'. They will charge a dollar for it.

Next we see how to use it

 

[robincnn]

It will be almost 0.1mm or 100 microns. Which is a good thickness.
50 -200 micron is what you need.


Now that you have printed your sheet looks like this.



Get a sharp blade and cut out the inner square.


Great now it is ready to use. Align the screw positions.
put some paste. Use your credit card or insurance card to spread out the paste evenly.

Now you have a perfect 100 micron or 0.1mm layer
You can wipe template so that you can see screw positions and reuse it several times.

 

[robincnn]

I have verified and the template for 3590 and Vero 29. I do not have 3070
I have tried by best to ensure accuracy. You can ungroup the items in MS word and then set MS word to MM scale and then reshape it to work with any COB
To ungroup just right click on the image and grouping > Ungroup

Great video that has been posted several times

In the video look carefully as they say
when you mount the array to heatsink it is recommenced you move the array rotated back and forth slightly to ensure TIM spreads out

Commercial way you do die cast and make them for about $0.25 to $0.50 each and $50-$100 Setup fee

 

[nogod_]

I actually tried this method but had a terrible time keeping the TIM from squeezing underneath the template.

So I switched to tape. Took a giant roll of masking tape and traced the 3590 dummy a couple times in while it was still on the roll. Cut along the lines (through a few layers of tape on the roll) and peel off stencil stickers.

Also works with any sticker paper, name tags are cheapest.

It will be almost 0.1mm or 100 microns. Which is a good thickness.
50 -200 micron is what you need.
View attachment 3586477

Now that you have printed your sheet looks like this.

View attachment 3586468

Get a sharp blade and cut out the inner square.
View attachment 3586471

Great not it is ready to use. Align the screw positions.
put some paste. Use your credit card or insurance card to spread out the paste evenly.

Now you have a perfect 100 micron or 0.1mm layer
View attachment 3586480

 

[robincnn]

@nogod_
I did not have the issue with TIM squeezing underneath the template. I like template way as it aligns with screws on heatsink and is transparent.
I like your tape idea too as long as the thickness is fine.

Open thread feel free to talk about your TIMs or pads
I use Artic Silver. I like Artic MX4 too as it is a little thinner and flows easily.

 

[nogod_]

Yeh I wish it was cheaper to buy custom die-cut vinyl stickers. I priced them out on a few websites and they wanted $90 or more just to make a custom die. Or they would do it for less if I committed to 1000 sheets [12000 templates]. Needless to say my addiction is not there yet!

Thanks for posting this I am always trying to find less messy ways of dealing with toxic goop!

@nogod_
I did not have the issue with TIM squeezing underneath the template. I like template way as it aligns with screws on heatsink and is transparent.
I like your tape idea too as long as the thickness is fine.

Open thread feel free to talk about your TIMs or pads
I use Artic Silver. I like Artic MX4 too as it is a little thinner and flows easily.

 

[welight]

guys why not just buy precut graphite thermal pads, lot less mess?
Cheers
Mark

 

[stardustsailor]

guys why not just buy precut graphite thermal pads, lot less mess?
Cheers
Mark

(...)The use of graphite is limited by its tendency to facilitate pitting corrosion in some stainless steel,[17][18] and to promote galvanic corrosion between dissimilar metals (due to its electrical conductivity). It is also corrosive to aluminium in the presence of moisture. For this reason, the US Air Force banned its use as a lubricant in aluminium aircraft,[19] and discouraged its use in aluminium-containing automatic weapons.[20] Even graphite pencil marks on aluminium parts may facilitate corrosion(...)

https://en.wikipedia.org/wiki/Graphite

A simple pencil mark can facilitate corrosion to aluminium ..
Let alone the " precut graphite thermal pads "...
Just forget it ....

 

[Greengenes707]

(...)The use of graphite is limited by its tendency to facilitate pitting corrosion in some stainless steel,[17][18] and to promote galvanic corrosion between dissimilar metals (due to its electrical conductivity). It is also corrosive to aluminium in the presence of moisture. For this reason, the US Air Force banned its use as a lubricant in aluminium aircraft,[19] and discouraged its use in aluminium-containing automatic weapons.[20] Even graphite pencil marks on aluminium parts may facilitate corrosion(...)

https://en.wikipedia.org/wiki/Graphite

A simple pencil mark can facilitate corrosion to aluminium ..
Let alone the " precut graphite thermal pads "...
Just forget it ....

I was so surprised when I saw cree recommending them with no specification of sink material used. Been waiting for someone else to speak up.

 

[stardustsailor]

I was so surprised when I saw cree recommending them with no specification of sink material used. Been waiting for someone else to speak up.

Cree uses ceramic material for casing it's COBs.
Since ceramic is non electrical conductive ,
there's no issue about graphite and galvanic corrosion .

A copper heat sink can be used with ceramic COBs and graphite TIM .
A ceramic heat sink also can be used .
But an aluminium heat sink remains out of question .

For aluminium cased COBs ,like the Vero series ,
graphite-containing TIMs is not an option .
Same goes with any liquid-metal TIM ,like Indalloy types ( 15-28 W/mK ) or
Coollaboratory Liquid Ultra / Pro or any other liquid-metal TIM ,
containing Indium or Gallium .
Can not be used with aluminium heat sink and/or aluminium cased COBs .
(Although ,they can be used with extreme caution ,at anodised aluminium heat sinks,
but personally wouldn't risk it .... )

 

[captainmorgan]

Your template may be too thin if the TIM is squeezing out past where you want it. The template I use is made from a sour cream lid and the hole is 1/4 inch smaller than the COB and uses the holders screw holes for alignment,it works great.

 

[FranJan]

(...)The use of graphite is limited by its tendency to facilitate pitting corrosion in some stainless steel,[17][18] and to promote galvanic corrosion between dissimilar metals (due to its electrical conductivity). It is also corrosive to aluminium in the presence of moisture. For this reason, the US Air Force banned its use as a lubricant in aluminium aircraft,[19] and discouraged its use in aluminium-containing automatic weapons.[20] Even graphite pencil marks on aluminium parts may facilitate corrosion(...)

https://en.wikipedia.org/wiki/Graphite

A simple pencil mark can facilitate corrosion to aluminium ..
Let alone the " precut graphite thermal pads "...
Just forget it ....

I was so surprised when I saw cree recommending them with no specification of sink material used. Been waiting for someone else to speak up.

You guys are like chicken little . Hopefully for those watching at home they checked that thing called the Interweb where they'd find out about things like aluminum graphite batteries and galvanizing and salt ions and how one mother-fucker out there has been running their Vero and Illumitex F1 based DIY grow lights using graphite and graphite based TIMs for years now because he saw professional LED lighting designers using it in their lamps and designs, though of course this doesn't make them right.

Plus SDS, don't believe anything the government of the US says. Well, OK, maybe if it's about their physical property which they care a shitload about, then yeah, OK, I'll believe you there .

Bottom line, paste is best and safest IMO,(and Supra style mounting won't work without it), but this thread, regardless of it's kind intentions, does beg the question; If you need help using Paste then how the fuck did your dumb-ass graduate kindergarten? Probably failed Milk and Blocks too LOL.

 

[stardustsailor]

You guys are like chicken little . Hopefully for those watching at home they checked that thing called the Interweb where they'd find out about things like aluminum graphite batteries and galvanizing and salt ions and how one mother-fucker out there has been running their Vero and Illumitex F1 based DIY grow lights using graphite and graphite based TIMs for years now because he saw professional LED lighting designers using it in their lamps and designs, though of course this doesn't make them right.

Plus SDS, don't believe anything the government of the US says. Well, OK, maybe if it's about their physical property which they care a shitload about, then yeah, OK, I'll believe you there .

Bottom line, paste is best and safest IMO,(and Supra style mounting won't work without it), but this thread, regardless of it's kind intentions, does beg the question; If you need help using Paste then how the fuck did your dumb-ass graduate kindergarten? Probably failed Milk and Blocks too LOL.

Fran ,it's not just me saying this ...
My previous job had something to do with aviation ...
(In case of someone asking this : Yes ,I can fly some types of aircrafts ,but not when I'm ...high ! )





(...)CPP measurements showed that the presence of Gr and the increase of its content with Al
increased the corrosion current, corrosion rate and decreased the polarization resistance (...)

http://www.electrochemsci.org/papers/vol6/6041085.pdf

Check also here for more info " MIL-STD-889 " :
http://quicksearch.dla.mil/qsDocDetails.aspx?ident_number=36032


Cheers.

 

[Abiqua]

I was so surprised when I saw cree recommending them with no specification of sink material used. Been waiting for someone else to speak up.

Im using graftech samples on copper slugs....Vero 29's and Meanwells so far...good #'s maybe great.....Graftech going on the BB's I just ordered @1050is Ma...on 460ish gram copper cpu plugs...

Thanks again too, big shout to PCL, wish I could get more

 

[Fastslappy]

I was so surprised when I saw cree recommending them with no specification of sink material used. Been waiting for someone else to speak up.

IIRC it's listed (grafite) as a no use item on aircraft
i was in a/c maint inna past life @ airlines

any of this is not a over nite reaction (pitting ) , it's along process but at high humidty that pace quickens Most app's for Cree cob's are in protected lights . hence the pads being safe
i'll err on side of caution & let someone else be a test bunny
just imo as a former A/C maint . type guy

 

[The Dawg]

You guys are like chicken little . Hopefully for those watching at home they checked that thing called the Interweb where they'd find out about things like aluminum graphite batteries and galvanizing and salt ions and how one mother-fucker out there has been running their Vero and Illumitex F1 based DIY grow lights using graphite and graphite based TIMs for years now because he saw professional LED lighting designers using it in their lamps and designs, though of course this doesn't make them right.

Plus SDS, don't believe anything the government of the US says. Well, OK, maybe if it's about their physical property which they care a shitload about, then yeah, OK, I'll believe you there .

Bottom line, paste is best and safest IMO,(and Supra style mounting won't work without it), but this thread, regardless of it's kind intentions, does beg the question; If you need help using Paste then how the fuck did your dumb-ass graduate kindergarten? Probably failed Milk and Blocks too LOL.

I Got Kickout Of Kindergarten Cause I Spilled My Milk While Kicking Frans Blocks Over

 

[The Dawg]

I Just Added A Whammy Bar To My Lights. Yes Folks If My Beloved Vero's Hit 105F A Heat Resistor Kicks In And Dim's Them Down. How Fucken Kewl Thanks Robin

 

[heckler73]

I Just Added A Whammy Bar To My Lights.

Nice avatar switch.
Now it looks like your pup is in an egg yolk.

 

[The Dawg]

Nice avatar switch.
Now it looks like your pup is in an egg yolk.

I Call Him The DawgFather

 

[woz from oz]

Cree uses ceramic material for casing it's COBs.
Since ceramic is non electrical conductive ,
there's no issue about graphite and galvanic corrosion .

A copper heat sink can be used with ceramic COBs and graphite TIM .
A ceramic heat sink also can be used .
But an aluminium heat sink remains out of question .

For aluminium cased COBs ,like the Vero series ,
graphite-containing TIMs is not an option .
Same goes with any liquid-metal TIM ,like Indalloy types ( 15-28 W/mK ) or
Coollaboratory Liquid Ultra / Pro or any other liquid-metal TIM ,
containing Indium or Gallium .
Can not be used with aluminium heat sink and/or aluminium cased COBs .
(Although ,they can be used with extreme caution ,at anodised aluminium heat sinks,
but personally wouldn't risk it .... )

Thank you for that information. I plan on using computer fan/heatsink combo and some come with a thermal paste patch already on the heat sink. (I think they are meant to cool Pentium chips.) The paste is dark so it probably contains graphite and as I'm using Veros should be removed and replaced with something more compatible.