Heat sinking???

Hi all.

I am about to buy and build a BR and Red lasers. The BR will give out about 100mW and the Red about 250mW.
At these powers, especially the Red, there will be a lot of heat generated.

The lasers are going to be in aixiz modules and then fitted into these boxes.

I would like to have a long duty cycle on these lasers, but to prolong thier life, I will need heat sinking. However I don't have the means to make a heat sink.

My only options at the moment are:
1. encase and fix the aixiz module into the host with some heat transfer compound, although I will have to find out if this stuff sets hard. But then this would make getting to the module very hard.
2. fix a small cooling fan inside the box and drill vent holes into the box.

What have others used as heat sinking to get a longer duty cycle?

Thanks.

I normally lathe up my own, or use CPU heatsinks.

But some ppl make them out of washers. Failing that, you could always get them made. Alluminum is cheap. Cost $10 to get one machined.

CPU Style

I saw the box that you need to fit into. You need to make something small. If you can get some thin sheet aluminum (home depot, etc.), you could cut a few small squares and drill (maybe need to file as well) them to fit snugly onto the aixiz housing, so the part of the aixiz housing that is inside your project box is finned like a cpu heatsink. Three or so of these fins would probably be enough. You could provide some ventilation holes in the box, and even a micro fan (fan probably not needed!).

Thanks guys, great ideas.

I can get my hands on some CPU heatsinks, but not sure how I would fit the aixiz to it.
I like the idea of fixing fins to the aixiz module itself. Would that really be enough to dissapate the heat?

I can get hold of a very small cooling fan too so I may use one of them and drill vent holes.

In the hobby box I am using in the pics above, I won't be using the black cable gromit to hold the aixiz module. In the pics above, those lasers are only 5mW red so it's not a problem. I also have a 50mW green in one of those boxes too but that don't produce heat.

With the BR and Red that I am making, the aixiz module will not be supported in the cable gromit because it is made of plastic and so will insulate the module, and probably make it overheat.
Instead I will simply fix the module to the inside of the box with just the end sticking out so I can adjust focus. Then drill some small vent holes near the module.
Then, if there is room, have a small fan that blows towards the module and blows heat out of the vents.

Actually I just found a hobby box the same size but made of aluminium.

If I fiited the aixiz into the box as shown in the pic below, would the box itself act as a heatsink?
The aixiz would be screwed together through a hole cut just bigger than the thread on the aixiz, so when the two halfs of the aixiz are screwed together, it will 'sandwich' between the aluminium box, forming a tight fit. And it is also exactly where the diode itself is, so at the point where the heat is generated.

Would this aluminium box be enough heatsink or should I also fit a small fan as shown too?
Maybe instead of a fan I could use some metal washers with the inside hole cut to size so it's a tght fit over the aixiz module then they would act as fins to radiate the heat away too?

Thanks.

mike666 said:

Actually I just found a hobby box the same size but made of aluminium.

If I fiited the aixiz into the box as shown in the pic below, would the box itself act as a heatsink?
The aixiz would be screwed together through a hole cut just bigger than the thread on the aixiz, so when the two halfs of the aixiz are screwed together, it will 'sandwich' between the aluminium box, forming a tight fit. And it is also exactly where the diode itself is, so at the point where the heat is generated.

Would this aluminium box be enough heatsink or should I also fit a small fan as shown too?
Maybe instead of a fan I could use some metal washers with the inside hole cut to size so it's a tght fit over the aixiz module then they would act as fins to radiate the heat away too?

Thanks.

Click to expand...

Yes, the aluminum will act as a heatsink. I have used aluminum tape from the hardware store and its pretty good at taking the heat away.

--hydro15

Thanks.

Another quick question.... would it be a good idea to drill some small vent holes into the aixiz module itself, because the LD driver can get rather warm too?

I've never seen this done so would rather know before I attempt it.

Follow this link http://z-bolt.com/MODIIIbg-green-laser-module.html and look under the three green modules in the list. There's a heatsink listed there that I myself use frequently. It is drilled for a fan, but you probably won't need it. It fits Aixiz modules perfectly, and allows for 100% duty.

ElektroFreak said:

Follow this link http://z-bolt.com/MODIIIbg-green-laser-module.html and look under the three green modules in the list. There's a heatsink listed there that I myself use frequently. It is drilled for a fan, but you probably won't need it. It fits Aixiz modules perfectly, and allows for 100% duty.

Click to expand...

Nice one. Thanks.