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FrozenGate by Avery

Copper plating AIXIZ modules *GRAPHS ADDED*

JLSE

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Dec 13, 2007
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Looking for some input on this idea... I have tried this and it works, but is the
idea of copper plating an AIXIZ module beneficial?

Two things come to mind... 1 it makes for a tighter fit for the LD by adding
a thin layer of copper, and 2, my thoughts are that the copper will assist in
transferring heat out to the heatsink.

I have no means to test this properly, and am looking for some views on the idea..
I'd imagine the difference would not be great, but every little extra counts.


Thoughts?



*EDIT*

So I plated some modules last night and will add a video shortly. The process to
copper plate is fast and simple. After playing around with it, I ended up finding
that it takes about 1min in the solution to produce a nice layer of copper over
the brass.

I first stripped the nickel plate off the modules with 30% sulfuric acid. This acid
was purchased from UAP NAPA auto parts supplier, but the same results can be
had with acid from a car battery..

I placed the modules in a plastic container and let sit for about an hour until
no nickel could be seen on the modules.

I then gave them a rinse in water mixed with baking soda to neutralize any
remaining acid.

For the copper solution I made use of used PCB etching fluid which was a nice
deep blue from all the copper I had once removed from copper clad when making
circuit boards. A great way to recycle this fluid. I have to find the bottle for
the acid that was used in this, but im sure any etching fluid saturated with
copper will do the trick. Keep in mind there are other ways to copper plate,
any of which would also work well here.

One thing to keep in mind, if you use an acid solution holding the copper,
immediately submerse the newly plated part in water mixed with baking soda
to neutralize and remaining acid on the part, then wipe dry with a clean cloth
and dry.

The power supply used was an old PC P/S running off the 3v rail.. Here are
a couple of pics of the bare brass after stripping the nickel, and beside
the newly plated copper one. I started with old modules that had dead diodes
pulled out, this is where the marks in the metal came from...

copper_plated_aixiz.jpg


Will be making a quick tutorial video for the process. Very simple to do, taking
about 1min per module to apply the plate..


*2nd EDIT* Tests done..

Well the results for the following tests are in :D

At 1A I tested the same diode in the same mount, same position and distance
from the sensor, and the lens focused to the same point...

Though I saw an odd slope is the plated tests, im seeing around 100mW more
when using copper plated brass with arctic silver paste over bare brass
with the same paste. I also graphed dry runs where there was no paste at
all..

Next test is going to be a diode mounted in a copper plated aixiz and
after the first test im going to plate the rear of the module with the diode
still in the mount...

I still have to try for the nickel vs copper plate, but will have to make a
removal tool so the diode doesnt get damage when removing.

Either way the results do seem to show an improvement and 100mW
is nothing to sneeze at..

BARE BRASS
bare_brass.jpg


BRASS + SILVER PASTE
brass_silver_paste_.jpg


COPPER PLATE NO PASTE
copper_plate_no_paste.jpg


COPPER PLATE + SILVER PASTE
copper_plate_silver_paste.jpg



*EDIT #3*

Another update, mounted the same LD in a copper plated aixiz with arctic
silver paste. Took another 45sec graph as well as after plating the base with
the LD already mounted..

The plating didnt take as well as I didnt give it a soak in sulfuric acid
prior to the plating and only cleaned away the excess arctic silver with
99% alcohol. I will have to repeat this one again on a cleaner diode
which should still give the difference..

I noticed that the aixiz mount was slightly lower in output @1A than in
the brass mount used in the fisrt tests. Im assuming that the first
mount held the LD via threaded ring applying pressure and more importantly
contact to the rear of the LD where in an aixiz mount there is no contact.

Though this didnt account for much of a difference between the 2 mounts
it may be attributed to different grades of brass. Hopefully the next plating
to the rear of an LD in the aixiz will show more definitive difference..

There was only a 10mW difference in favor to the plated LD base on this run..
Yet a difference none the less. Same conditions again of focus and positioning
in relation to the LPM sensor and orientation in the AL heatsink.

COPPER PLATED AIXIZ + SILVER PASTE
DSC03559.jpg

copper_plated_aixiz_silver_paste.jpg



SAME COPPER PLATED AIXIZ + SILVER PASTE + PLATED LD BACK
DSC03575.jpg

LD_base_plated_.jpg
 
Last edited:





Re: Copper platting AIXIZ modules?

Just pressing the LD tighter in the housing should
help in thermal transfer I would think...

Besides the Copper will make the Aixiz modules
look way cool...:D


Jerry
 
Re: Copper platting AIXIZ modules?

the only problem i see is that it might be too tight. while the plating is thin it is there.

michael.
 
Re: Copper platting AIXIZ modules?

Just pressing the LD tighter in the housing should
help in thermal transfer I would think...

Besides the Copper will make the Aixiz modules
look way cool...:D


Jerry

Well another example I can think of is how LD's are gold plate over
copper.. Is this for sake of electrical conductivity or thermal?

Even though its only a thin layer, why go through the trouble of
gold plate on the LD's?

I can see if it were for corrosion resistance, but im thinking there
is more to it..

Im about to mount 24 LD's, and am considering it.

the only problem i see is that it might be too tight. while the plating is thin it is there.

michael.

Tried this with one module just to see, and the LD fits snug.. Perhaps the
mount was one of the looser fit I find from time to time.

I think ill pate a bunch and any that seem to be too tight, I can just
sand off a little with fine sandpaper on the lathe.

I could just make copper mounts, but have a handful of aixiz modules left
to put to good use..
 
Re: Copper plating AIXIZ modules?

At this point, where the diode already fit very tight in the AIXIZ module,
IMHO what I consider very important for a good heat transfer,
is to put a small amount of a very good thermal paste when insert
the diode in the module, to fill the gaps of the micro-imperfections
that exist between the two metals.

Because as you know, the better the contact between the two metals,
the better the heat transfer, and in this case I think a thermal paste
do a very good job, perhaps better than adding a thin layer of copper.

This is only my personal opinion, and of course I can be wrong,
but I always obtained good results with this technique.

Well, if you combine the 2 techniques, great haha.

As always apologies, if not properly express myself in English.
 
Re: Copper plating AIXIZ modules?

You make perfect sense.. I use silver paste to set the diodes normally weather
or not the mount is an aixiz or one of my own copper modules.

The idea of the plating is that copper will conduct the heat away from the diode
better than the brass which the aixiz are made from. On top of the brass
the aixiz modules are nickel plated which is also not the greatest of conductors
for heat. The idea of the copper plating would possibly allow a better thermal
transfer from the diode out to the larger aluminum heatsink..


My only question is if copper will maintain its properties even if the contact
is made via plating opposed to a solid piece..

In theory it sounds like a good idea, but if it in fact will add any benefit
remains to be seen.

Maybe I should skip the copper plate and plate with silver instead :thinking:





At this point, where the diode already fit very tight in the AIXIZ module,
IMHO what I consider very important for a good heat transfer,
is to put a small amount of a very good thermal paste when insert
the diode in the module, to fill the gaps of the micro-imperfections
that exist between the two metals.

Because as you know, the better the contact between the two metals,
the better the heat transfer, and in this case I think a thermal paste
do a very good job, perhaps better than adding a thin layer of copper.

This is only my personal opinion, and of course I can be wrong,
but I always obtained good results with this technique.

Well, if you combine the 2 techniques, great haha.

As always apologies, if not properly express myself in English.
 
Re: Copper plating AIXIZ modules?

What if you plated just the back of an aixis module, with the diode already in it?

Im not sure if it would work like this but Im picturing the copper (or whatever you use) filing in the cracks between the diode/module fusing them together and maybe making a flat seamless surface on the back between the diode/module.
 
Re: Copper plating AIXIZ modules?

@wannaburn, Well, I couldn't say whether the results will be significant, but better than without the copper, I guess so.

An idea also, in regard to the AIXIZ module with the heat sink, one thing what works well
(whenever possible to) is make the interior hole of the heat sink ~1 or 2 tenths
of a millimeter smaller than the AIXIZ module (also depends on the material used
to make the heat sink, copper, aluminum...), then put the heat sink into
an oven at ~200°C. to make this dilate enough, and permits the AIXIZ module
fits into the heat sink, then that will cool, then the 2 pieces remain
firmly attached and with a very good thermal transfer.

The heat transmitted to the module and finally to the diode with this technique
not damaged this, because once placed the module in the heat sink, must be cooled immediately
with a damp cloth to prevent transfer much heat to the diode.

If in addition if the AIXIZ module has a thin layer of copper, even better :beer:

Obviously the only problem with this technique, apart from being able to make the
heat sink with this precision, is if you need separate them later, it almost impossible.

Well just an idea.
 
Last edited:
Re: Copper plating AIXIZ modules?

What if you plated just the back of an aixis module, with the diode already in it?

Im not sure if it would work like this but Im picturing the copper (or whatever you use) filing in the cracks between the diode/module fusing them together and maybe making a flat seamless surface on the back between the diode/module.

There is something about putting an LD into a electrified
copper solution that just screams DON'T DO IT at me...:eek:
I may be wrong...:undecided:

I could also see the possibility of the copper plating from
the LD pins across to the base of the LD...


Jerry
 
Last edited:
Re: Copper plating AIXIZ modules?

Well, I don't see why it wouldn't make for better thermal transfer :D

IF you remove the nickel and replace it with copper it would help.
 
Re: Copper plating AIXIZ modules?

Copper can be built up pretty heavy, it might make a loose module fit better. I don't think the copper will adhere to the nickel plate too well though. If you focus the laser a lot it might wear off and mess with your lens and diode. The threads on aixiz modules are usually loose enough that a lens would still fit and the diode pocket could easily be taken back to the proper size with an xacto knife or something similar.

If you had a way to remove all of the nickel plate (sandblasting?) it might work OK. Otherwise I would think it would cause more trouble than good.
 
Re: Copper plating AIXIZ modules?

I could probably plate an assembled module just on the back, but it runs
the risk of some complications. The 2 isolated pins would probably not plate
unless they are connected to the body of the mount. Only the 3rd ground pin
should plate as well as the LD body.

I may try this on a PHR LD just to see what happens.

So now im thinking to strip the nickel and either a straight silver plate or
copper then silver. I'm not sure how silver plates directly to brass, but will
find out. Shouldn't be a problem with just silver over the brass..

I was thinking of gold, but the plating solution for gold is nasty vs copper
or silver. There are plating kits available for gold, but I think its wise to try
these out first.


Copper can be built up pretty heavy, it might make a loose module fit better. I don't think the copper will adhere to the nickel plate too well though. If you focus the laser a lot it might wear off and mess with your lens and diode. The threads on aixiz modules are usually loose enough that a lens would still fit and the diode pocket could easily be taken back to the proper size with an xacto knife or something similar.

If you had a way to remove all of the nickel plate (sandblasting?) it might work OK. Otherwise I would think it would cause more trouble than good.

The nickel is fairly easy to strip.. I tried old PCB etching acid, and it does a thorough job. To speed it
up, I can also use some contaminated sulfuric acid from my anodize tank.. It would strip the nickel in
seconds if you apply a charge.

The original idea and what I tried was plating the outside only, leaving the threads for the lenses untouched.
Though it may not be a bad idea to strip it all and place a nice thick coat to pick up the slack for the lens.

Should the threads need cleaning, I can always run a tap down them...
 
Last edited:
Re: Copper plating AIXIZ modules?

There is something about putting an LD into a electrified
copper solution that just screams DON'T DO IT at me...:eek:
I may be wrong...:undecided:

I could also see the possibility of the copper plating from
the LD pins across to the base of the LD...


Jerry
Hmmm I guess if it was an LD that wasn't isolated case and you were plating with "high" voltages (like 12-24v) I see how it could draw some current, maybe even enough to kill some diodes. As long as you are using low voltages, say 3v or so, I don't think it could affect it in any way.

I have seen some plating liquids that don't use electroplating. The metal just deposits out of the liquid. I imagine that these are very expensive though and I've never seen it in copper.

I did think about the pins bridging to the case, but I figured there was probably enough space to prevent this as long as you dont let it get too thick. And if it does bridge you could easily fix it with an exacto knife.
 
Re: Copper plating AIXIZ modules?

We're beating a dead horse with another dead horse. Cu, Al, and brass all offer excellent conduction. It's JUNCTIONS that need to be eliminated.

It's good enough as at is. If you're really concerned about the health of the diode, a better area to tackle would be limiting the current. If you're stubborn about maximizing heat transfer, eliminate the aixiz-to-heatsink junction. Use one mass of metal. In real-world scenarios, the choice of copper over brass or copper over aluminum will not provide nearly the improvement that most of you seem to expect of it.
 
Re: Copper plating AIXIZ modules?

^^ The idea here is to make an improvement of an existing product. Even if the
improvement is small, it better than no improvement at all..

So I plated some modules last night and will add a video shortly. The process to
copper plate is fast and simple. After playing around with it, I ended up finding
that it takes about 1min in the solution to produce a nice layer of copper over
the brass.

I first stripped the nickel plate off the modules with 30% sulfuric acid. This acid
was purchased from UAP NAPA auto parts supplier, but the same results can be
had with acid from a car battery..

I placed the modules in a plastic container and let sit for about an hour until
no nickel could be seen on the modules.

I then gave them a rinse in water mixed with baking soda to neutralize any
remaining acid.

For the copper solution I made use of used PCB etching fluid which was a nice
deep blue from all the copper I had once removed from copper clad when making
circuit boards. A great way to recycle this fluid. I have to find the bottle for
the acid that was used in this, but im sure any etching fluid saturated with
copper will do the trick. Keep in mind there are other ways to copper plate,
any of which would also work well here.

One thing to keep in mind, if you use an acid solution holding the copper,
immediately submerse the newly plated part in water mixed with baking soda
to neutralize and remaining acid on the part, then wipe dry with a clean cloth
and dry.

The power supply used was an old PC P/S running off the 3v rail.. Here are
a couple of pics of the bare brass after stripping the nickel, and beside
the newly plated copper one. I started with old modules that had dead diodes
pulled out, this is where the marks in the metal came from...

copper_plated_aixiz.jpg


Will be making a quick tutorial video for the process. Very simple to do, taking
about 1min per module to apply the plate..
 
Re: Copper plating AIXIZ modules *PICS ADDED

Wow. I dont know if that will do anything, but those look great

+1 if I can
 





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