Best thermal pathway for heatsinks

[rhd]

From an email from DTR a while back,

Back threads are M11x0.5mm

If someone was willing to do the tapping, we could have backs made for ~$3 (aluminum) or $5 (copper) with a QTY of 100+ that would work sort of like this:

Though I'm sure there are people on the forum with more established ongoing relationship with machinists / CNC providers that could probably get a better deal (and have the tapping done as part of the price).

 

[Shakenawake]

op::gh:

 

[BShanahan14rulz]

Are you still using a setscrew heatsink? Adding thermal mass to the 12mm module can only go so far, just don't forget about the heatsink.

Perhaps a standard "socket" layout can be devised so that in the future, you simply machine this complicated bit in the middle of your heatsink instead of drilling that complex 12mm hole. The bit would incorporate a face that butts up against the rear of the actual diode, and would use the aixiz module's screws to provide the pressure.

Ok, that would take some fancy machining, but what about:

What about a C-shaped with screws to clamp the open end of the C shut?

Or a cylinder bisected with screws at the corners to clamp module between them?

These ways can also facilitate the use of an interface material if necessary or wanted.

 

[TheDukeAnumber1]

I've had no problems filling the gap with thermal epoxy, I've even used a glue gun before. Conducts heat better than air.

Also ricktrent offers modules that are supposed to contact the back of the diode.
http://www.ebay.com/itm/Laser-heat-sinks-for-9mm-diodes-11-9mm-x31-5mm-copper-module-/321238757565?pt=LH_DefaultDomain_0&hash=item4acb5270bd

 

[ricktrent4]

This is a photo of my 9mm copper module as you can see the diode touches the back of the diode and it is 12mm X32mm I use is in my knife edging kit
I am having some new bigger copper heat sinks made that fit the mx900 flashlight that this will drop in to and have a set screw in the side you would just need to add Arctic Silver 5 Premium High Density Silver Thermal Paste Compound

 

[Shakenawake]

the pic ricktrent just posted is exactly what I need, except it is too long. I need it for my DominatoR heat sink. It would need to be half that length or even less.

can I buy one from him then have it sent to someone for cutting?

 

[IsaacT]

Why don't people just ask that the interior of their heatsink(when they order it) have threading available to lock the module in place. Then the heatsink is DIRECTLY threaded onto the module and is much better at heatsinking. It wouldn't be that hard to do, any of the machinists on the forum should be capable of it.

 

[Shakenawake]

Can't threads in copper be difficult to machine? ones in the heat sink would be "male" threads, no? cant be carved out of the heatsink, the heat sink must be carved out around them, I bet that's harder, but I could be wrong.

I was thinking the same thing though, just notch the module so it can be screwed in flush. could probably do that with a saw of some sort, obviously a thin one. knowing me I'd overtighten it and strip the theading, so if I ever get one of these concepts come to life, I will be sure to not do that

 

[BShanahan14rulz]

...Perhaps a standard "socket" layout can be devised so that in the future, you simply machine this complicated bit in the middle of your heatsink instead of drilling that complex 12mm hole. The bit would incorporate a face that butts up against the rear of the actual diode, and would use the aixiz module's screws to provide the pressure....

Ricktrent4's copper aixiz replacement:

Why don't people just ask that the interior of their heatsink(when they order it) have threading available to lock the module in place. Then the heatsink is DIRECTLY threaded onto the module and is much better at heatsinking. It wouldn't be that hard to do, any of the machinists on the forum should be capable of it.

This. It needs to become some sort of agreed-upon standard. You would simply need the heatsink to have the threads and hole machined into them, just like the piece on the right side of ricktrent4's picture, except instead of machining it out of 12mm copper bar, you would machine it straight out of your heatsink.

Here's a thought exercise for anybody: take a circle. Now, make a slightly smaller circle. Put the small circle inside the larger circle so that the two are touching. You will notice that the circles only touch in one spot. This is like using a setscrew in your heatsink. The module only contacts the heatsink in one spot (or, along one line, since it is 3-dimensional), plus the minute area that the setscrew itself touches.

 

[ricktrent4]

The one I am having made will be a tight fit and will have test screw .this is good so you can test driver out before you add diode module . I will make video as soon as they come in.​

 

[DTR]

the pic ricktrent just posted is exactly what I need, except it is too long. I need it for my DominatoR heat sink. It would need to be half that length or even less.

can I buy one from him then have it sent to someone for cutting?

That is why I have two sizes for the 9mm thermal back half. The larger slug style one for regular 12mm set screw hosts and the shorter one for some of the new direct press hosts like the sinner ones. It will be hard to press a sold 18mm piece into a sinner head or similar direct press host along with the module in front of it. Trust me I tried and broke my vice

All my 9mm diodes in modules come with the larger thermal back half slug standard except those with drivers which the hollow aluminum back half which works to fill in the thread gaps. If you need the shorter back half you can request it and I will use them instead of the longer one. Also if you want the large slug back half and the driver separated by leads to sink to your host body that is available as well by request.:beer:

You will be hard pressed to find any performance difference with this particular part being copper vs aluminum but for the copper lovers I have some in copper coming as well.

 

[BShanahan14rulz]

Another thing that is worth mentioning, is machining tolerances. If someone machines you a custom module and heatsink meant for an interference fit, do that. The machinist will know what he is doing and allow for the correct tolerance to ensure proper interference fit. Mass produced modules are much more variable, with varying plating thickness, machining quality, and surface smoothness. If the machinist who turns your heatsink allows for those tolerances, you end up with potentially a fairly sloppy fit.

 

[ricktrent4]

that is some good work !

That is why I have two sizes for the 9mm thermal back half. The larger slug style one for regular 12mm set screw hosts and the shorter one for some of the new direct press hosts like the sinner ones. It will be hard to press a sold 18mm piece into a sinner head or similar direct press host along with the module in front of it. Trust me I tried and broke my vice

All my 9mm diodes in modules come with the larger thermal back half slug standard except those with drivers which the hollow aluminum back half which works to fill in the thread gaps. If you need the shorter back half you can request it and I will use them instead of the longer one. Also if you want the large slug back half and the driver separated by leads to sink to your host body that is available as well by request.:beer:

You will be hard pressed to find any performance difference with this particular part being copper vs aluminum but for the copper lovers I have some in copper coming as well.

 

[TheDukeAnumber1]

That is why I have two sizes for the 9mm thermal back half. The larger slug style one for regular 12mm set screw hosts and the shorter one for some of the new direct press hosts like the sinner ones. It will be hard to press a sold 18mm piece into a sinner head or similar direct press host along with the module in front of it. Trust me I tried and broke my vice

If only I didn't learn that one the hard way too

 

[Cel]

I think we should set some standards to make everything easier.

Firstly, the modules that could be screwed into a heatsink are a great idea.
Also those back halves (like those in the DRT's modules) are great for heatsinks that have a simple hole machined in them, without threads. (that look like cylinders)

So there are 2 variants.


And for better conductivity, the back of the diode should be used too. But then the pins should be insulated to prevent shorting. So the solution would be some kind of a threaded ring, like the lens holder but for the back of the diode...


Is it better to just direct press a diode into a module or apply some thermal paste and then press it?
What is the diode made of (its body)? Brass?
How often is thermal paste applied between the module and the heatsink?

 

[ryansoh3]

I may be able to do a GB of the front of the copper pills without the threads at the outside back.

That way, if we get a heatsink like this, we can both heatsink the sides (completely) as well as the bottom of the diode.

Target price is $4.00 but at 500 units.