New Aixiz modules from Aixiz are different

One of my customers confirmed my suspicion of the new Aixiz modules being ever so slightly different than the previous ones. This occurred when Aixiz ran out of stock for about 1 month and now all the modules shipping are different.

"previous modules were 11.95mm diameter, new ones are 11.87mm diameter. (checked with digital caliper, 3 old modules vs 2 new ones)" This is the outside diameter of the module's head (the part the diode goes into to). Also the hole that the diode goes into is different now.
I am pretty sure the old modules had a slight beveled edge that was on the edge where the the diode presses down into, and I believe the new modules don't have this beveled edge but rather it is straight down. This might just be my perspective though, there very well may not have been a beveled edge on the old modules. It does seem that diodes would fit better in the older modules though.

Here's some pictures trying to show my comparison.. I really need a better camera if I want to show any kind of detail though, which as it turns out was just shipped today by Dell so I will have a much better camera by 6/16/2009.




Here's a video made by one of my customer's as well, he is using one of the new Aixiz modules:


Also I wanted to point out that the Sure Electronics modules have not changed and I think diodes seem to fit in the module's hole just the same as the old Aixiz modules did. To have full disclosure I do sell both type modules and have a few hundred of each, so it would be in my best interest to not tell everyone about the different Aixiz modules but I wanted to let people know.

Perhaps someone with more precise measurement tools and that owns both an old and new Aixiz module could chime in here?

thanks,
Kendall

Thats odd... does that diode in the video site so loosely that i just falls out? Or are you supposed to push it down deeper where it does fit snugly?

UH, i still have 4 or 5 of the old ones, and i'm just waiting they send me 10 of the new ones ..... don't know when they arrives, anyway you just pointed about a possible problem, if they're not the right diameter for diode fix (5.54 to 5.56, in the ones i have here)

Can always just use thermoconductive glue, but it's not a good thing if they're too large.

btw, in your pics it's not too much clear, but can you please check also if the step where the diode sit is a 90 degree angle, or if is a conical shape ?

I mean, where the body of the diode stop when you press it full inside ..... in the old modules, it look as 90 degrees, where in the pic you posted, at new one, it look a bit "rippled", don't know the right term, not smooth and clear, anyway ..... being part of the dissipation path, other than the border that keep the diode aligned with the rest of the head, also this have its little importance.

HIMNL9 said:

UH, i still have 4 or 5 of the old ones, and i'm just waiting they send me 10 of the new ones ..... don't know when they arrives, anyway you just pointed about a possible problem, if they're not the right diameter for diode fix (5.54 to 5.56, in the ones i have here)

Can always just use thermoconductive glue, but it's not a good thing if they're too large.

btw, in your pics it's not too much clear, but can you please check also if the step where the diode sit is a 90 degree angle, or if is a conical shape ?

I mean, where the body of the diode stop when you press it full inside ..... in the old modules, it look as 90 degrees, where in the pic you posted, at new one, it look a bit "rippled", don't know the right term, not smooth and clear, anyway ..... being part of the dissipation path, other than the border that keep the diode aligned with the rest of the head, also this have its little importance.

Click to expand...

can you draw a picture or something? I'm not sure what you mean..

to be clear. the new modules still work just fine. apparently that guy had a problem with the fit of his 635nm diode. My LPC815, PHR803T, and GGWH20L diodes still fit just fine.

Sorry, i had to think this before

Hope te draws are clear enough, cause is a lot of time that i don't do tech draws

Ok, i know that we're speaking about small surfaces, but remember that all the heat that the diode generates during the run time, is dissipated mainly through those little surfaces ..... if only the external border touch, it's just a cylinder of 5,6mm of diameter and 1,2mm of height (with 3 gaps, too ) ..... a border that perfectly fit the front space, is always 50% more heat exchange surface, and if for 10 mw can count nothing, when you speak about 300 / 400 mw, it start to have its own importance also just that

HIMNL9 said:

Sorry, i had to think this before

Hope te draws are clear enough, cause is a lot of time that i don't do tech draws

Ok, i know that we're speaking about small surfaces, but remember that all the heat that the diode generates during the run time, is dissipated mainly through those little surfaces ..... if only the external border touch, it's just a cylinder of 5,6mm of diameter and 1,2mm of height (with 3 gaps, too ) ..... a border that perfectly fit the front space, is always 50% more heat exchange surface, and if for 10 mw can count nothing, when you speak about 300 / 400 mw, it start to have its own importance also just that

Click to expand...

oh Ok I see what you mean now.

Using a magnifying glass the edge where the diode is pressed into is still 90 degrees, looking at it only the top 1mm or so is beveled, top being the first part of the module that you would press the diode into, bottom being the bottom of where the diode presses when fully pressed in.

Now that I look at a new and old one the hole where the diode goes into does actually look the same, as far as the beveled edge on the hole is concerned. Perhaps its just the size of the diameter that changed. I'm not really sure... I do know they are ever so slightly different though.

sk8er4514 said:

can you draw a picture or something? I'm not sure what you mean..

to be clear. the new modules still work just fine. apparently that guy had a problem with the fit of his 635nm diode. My LPC815, PHR803T, and GGWH20L diodes still fit just fine.

Click to expand...

I had a problem fitting a PHR, and that's why I tried a 635nm diode.

I just measured the diode pocket diameter, and it is 0.24mm wider in the new modules. That leaves a 0.12mm gap around the diode... Way too much.

Edit: my caliper is accurate to a 100th of a millimeter, Mahr brand (good one, not a chinese caliper but a german one), or 0.0001 inches. I also have a micrometer that is accurate to a 10000th of a millimeter, made in switzerland and like 40 years old but it's as accurate as when it was new. (but that one doesn't measure inner diameters LOL)
Do you want precission?

Benm said:

Thats odd... does that diode in the video site so loosely that i just falls out? Or are you supposed to push it down deeper where it does fit snugly?

Click to expand...

Nope, there's no more way down. It just falls. I can also record another video with a PHR or a crappy and almost destroyed IR diode, to see that it's not a diode's problem but a module's.


edit3: Just found another Aixiz module head, probably the first one I bough, and it is 11.85mm wide... I first ordered 1 piece, and 3 months after 3 more pieces. It seems that my first piece has the same diameter as the new modules where the other 3 are a bit wider.

nice. well i stand corrected.

for some reason all the PHR803T diodes I've used still work. I am using a diode press tool from TheMonk. works magic.

i just had 20 new aixiz modules that i used, i didn't have any problems like that where the diode just falls right out.

i did notice a few pop right in ALOT easier than normal.....they went in easy enough to make me unsure about how snug they were....ie: took almost none or a tiny amount of pressure to press them in.

Not thoughd to measure also the outside, before ..... i took some measures from the 5 old ones that i have here.

out ............... diode side
V .................. V

11.88 ............ 5.55
11.92 ............ 5.56
11.96 ............ 5.54
11.92 ............ 5.57
11.94 ............ 5.56

it's a bit too few for have a precise idea, but seem all result of one of those automatic high-speed machines, that don't care too much about centesimal precision, at advantage of cheap mass production (well, for sure, in the place where i was working years ago, that have a tolerance policy of +0.0/-0.002, if there was a production with these tolerances, they was all discarded, LOL)

I'm curious to see the new ones, too, but i probably get them only in 2 or 3 weeks

Mohrenberg said:

i just had 20 new aixiz modules that i used, i didn't have any problems like that where the diode just falls right out.

i did notice a few pop right in ALOT easier than normal.....they went in easy enough to make me unsure about how snug they were....ie: took almost none or a tiny amount of pressure to press them in.

Click to expand...

That's quite worrysome really. With the contact area as small as it is, it should take quite some force to insert it to ensure proper thermal contact. For the original application of 10 mW lasers it doesnt matter at all, but by the time you're pushing 1+ watt through it, its a different story. As for the drawings of the inner bezel: The contact at the 'front' of the laser diode base isn't very important - the way there are inserted, there is little or no contact pressure in that direction even if it is flat.

I suppose it's possible to use thermally conductive adhesive to mitigate the problem, but that would leave the module pretty much useless when the diode dies. Thermal paste could help a bit too.

It's all speculation though, we'd need to have a look at the installed and operating part through FLIR to see what the differences are. It might also be possible to use the laser diode itself as a thermal sensor by running 2 side by side at regulated current and measuring any drop in forward voltage.

If you want a permanent installation, thermoconductive glue is ok (thermal paste is not ok, if the diameter is larger than the diode, cause it don't make any retain force).

But if you still want to use the larger module without glue them, just use a little strip of cooking aluminium foil ..... need some care placing it properly, anyway one, or at maximum two, turns around the diode pressing side, must be enough for ensure a decent spacer and thermal transfer, without made the module useless if you have to change the diode.

Also better, those metal spacer tapes / foils for mechanical alignments, they sold them in differents thickness, from 0.001mm, i think the less thick ones.

Maybe it's not an elegant solution, but at least it work

The contact at the 'front' of the laser diode base isn't very important - the way there are inserted, there is little or no contact pressure in that direction even if it is flat.

Click to expand...

I use a little bit of thermal paste there, for diodes over 50 mW ..... better more than less, in thermal exchange