Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

Heatsink problems

Joined
Mar 25, 2008
Messages
215
Points
0
Been a while since I posted here last time, but since I have a lot of free time over the summer I've decided to continue my 650nm build.

A while ago I made a heatsink in aluminum, but it was something odd with the drill I used to make the hole. So now there is a gap of 0.5mm or something like that between the Aixiz module and the heatsink. I also have a brass tube I can use, and the inner diameter and that of the module fits perfectly, but it's a teeny bit small for my host.

Any ideas of what I could do? I can't make a new heatsink since I don't have access to the tools anymore, and I can't afford to buy one.

EDIT: Okay, so I've experimented a bit. I can wrap some aluminum foil around the Aixiz module and make it fit inside the heatsink. The problem as I see it is that there will be some air I can't remove, but I'm thinking of applying some heatsink paste between every layer to minimize the conducting problems. Good idea / bad idea?
 
Last edited:
  • Like
Reactions: ARG





Joined
Jul 12, 2008
Messages
634
Points
28
I have heard of others using washers...
like for bolts. they are really cheap.. 0.10¢ or so for each one.
i do not think foil will work though.
 

cust11

0
Joined
Jun 21, 2009
Messages
471
Points
0
Been a while since I posted here last time, but since I have a lot of free time over the summer I've decided to continue my 650nm build.

A while ago I made a heatsink in aluminum, but it was something odd with the drill I used to make the hole. So now there is a gap of 0.5mm or something like that between the Aixiz module and the heatsink. I also have a brass tube I can use, and the inner diameter and that of the module fits perfectly, but it's a teeny bit small for my host.

Any ideas of what I could do? I can't make a new heatsink since I don't have access to the tools anymore, and I can't afford to buy one.

EDIT: Okay, so I've experimented a bit. I can wrap some aluminum foil around the Aixiz module and make it fit inside the heatsink. The problem as I see it is that there will be some air I can't remove, but I'm thinking of applying some heatsink paste between every layer to minimize the conducting problems. Good idea / bad idea?

Good idea with the thermal paste to close the air gap. I personally suggest arctic-cooling brand. I use MX-2 on my lasers and all of the computers I build. Looking at the big picture though.. any thermal compound will do just fine. We are only talking about slight degree changes whereas a processor will melt your finger in 3 seconds. Hope this helps.

-Mike
 
Joined
Jul 24, 2007
Messages
2,749
Points
0
Arctic silver do a thermal epoxy glue, google it or search for it here, it has been discussed on the forums.
You get the thermal contact and a good strong fixing as well.

Regards rog8811
 
Joined
Feb 1, 2008
Messages
2,894
Points
0
mix artic silver with some aluminum shavings to make a nice gap filling paste-glue.
 

HIMNL9

0
Joined
May 26, 2009
Messages
5,318
Points
0
^ i do the same, basically ..... got some 600mesh aluminium powder from art deco shop (the product that is usually used for do silver decorations and thermite :whistle:), and mix it with epoxy glue, making it better thermally conductive.

Just be careful to not blow too much hard, when you're using that AL powder ..... one "atchoo", and you get half room silver-glitting :p :crackup:
 

Krutz

0
Joined
Nov 21, 2007
Messages
1,733
Points
48
i use copper heatsinks, and directly solder the aixiz module into it with a small blowtorch. amazing, how much solder fits in a small gap! pre-tin both surfaces (with solder paste, for me).
well, in your case, aluminum. no (easy) way to solder this. at least you could widen the aixiz with solder, then sand it down again to the right diameter. probably its all too much effort. depends on how hard you want to drive the laser, how much heat there will be to begin with. perhaps its worth for a LOC at 500mA, thats what i cool with my heatsink anyway, no dutycycle needed.

manuel
 

Benm

0
Joined
Aug 16, 2007
Messages
7,896
Points
113
Well, solder is not that thermally conductive to begin with, but its better than paste.

Aluminium cannot be soldered though (using normal means). You could tin the outside of the module with solder such that it fits very snug and then ram it in (solder is quite malleable when solidified).

Using thermal paste is normally fine, but 0.5 mm is a hell of a gap to fill with the stuff. Perhaps it is possible to get some copper foil that fits the difference, and cut a piece that fits around the axiz in a single turn. With some additional paste, it might just work out.
 

HIMNL9

0
Joined
May 26, 2009
Messages
5,318
Points
0
^ or solder the copper foil on the aixiz module too ..... or solder the module on the aluminium heatsink, but for this you need special indium alloy soldering wire .....
 

Krutz

0
Joined
Nov 21, 2007
Messages
1,733
Points
48
what? you can solder aluminum with indium? oh great! if so, it should work with pure indium too, i guess? could i solder tin/lead to the indium-surface, afterwards?
i heard i could even solder to glass and ceramics with indium. but never thought of aluminum! that would really change a lot!

will definitely try this out!

manuel
 
Joined
Mar 8, 2009
Messages
710
Points
0
I think the indium would just fill out the intermediate space so that the two pieces are held by adhesion; I don't think it would be a real solder connection where there is metal diffusion to at least some atomic layers depth.

So I also think if you tried to put a solder layer onto your indium layer, you'd just destroy the latter as it has a much lower melting point. But if you have the material for just trying it out, go for it!
 

HIMNL9

0
Joined
May 26, 2009
Messages
5,318
Points
0
Sorry, i don't remember the exact composition of the alloy needed for aluminium soldering, but there's shops specialized that sold the alloy with already flux core inside ..... not cheap, anyway .....

someone sold it as pre-mixed soldering paste, mixed with fluxant, like this one, as example

3 Aluminum Solder Paste For Jewelry & Metal Welding - eBay (item 350221255357 end time Aug-01-09 21:51:41 PDT)

some other sold it as wire + fluxant, also, but they never declare the composition of the alloy

Harris Al-Solder 500 Aluminum Solder Kit - eBay (item 350220691860 end time Jul-31-09 16:38:39 PDT)

Anyway, solder aluminium is not the more easy way, let me say it :p
 




Top