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ArcticMyst Security by Avery

16x BDR-209 build problem

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hi all been sometime i posted on the forum,1st of all sory for my enlgish.

i was working on a custom laser with the diode extracted from 16x BDR-209 after alot of work several problems pattient and extra care to not burn anything i managed to make the laser working with a cheap 405nm driver set at 500mah(i had bad luck on the 405 wavelengh so i set it low just to be sure).im using a 405 3 element glass lense and its it has a nice beam,the problem i noticed is when i unfocused it and noticed some weird patterns,so i took of the lense and something was looking bad,i checked the diode and from what i can manage to see on this little thing is that the litle glass is missing? :eek:
in the 2nd image you can see the output without lense

https://s18.postimg.org/u36k0yfq1/IMG_20170330_175556.jpg

https://s30.postimg.org/56r1vw69d/IMG_20170330_175632.jpg
 





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i dont have a good macro camera but ill try tomorrow.this is weird because there wasnt any glass pieces or something like that inside the housing,how the hell this happened?does those diode decrade when the dont have window?i guess i cant do much more than use it till it dies.
btw the window i dont think it broke from temp due to any junk stuck on it because i run it at less power and never let it on more than 20 seconds
 
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With the glass missing, the diode's emitter is exposed to the ambient environment. This would be comparable to a decanned diode.
 

Benm

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That generally is no problem though, apart from taking extra precautions against dust ingress. Then again, the window protects the diode from dust, but often dust particles melt onto the window making the diode unusable unless you remove the window ;)

I can't tell much from the pictures, but if the output pattern without a lens in front of it is uneven, chances are that something got baked on the output window, or since that seems to be missing, the output faced of the die itself. How badly this affect output when used with a lens varies wildly.
 
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ok, i managed to take a not so good pictures of the diode with a galaxy s5 mini and except the thermal paste that is around i see no glass window and the diode looks like something hit it in front of it?i have no idea how this could happened,maybe on diode extraction?
i had this diode some months sitting and w8ting for a project,if i remember corectly i made the extraction from the sled so maybe i did something wrong.

https://s2.postimg.org/f00ylsus9/image.jpg

https://s18.postimg.org/wnc6epgex/image.jpg
 

diachi

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ok, i managed to take a not so good pictures of the diode with a galaxy s5 mini and except the thermal paste that is around i see no glass window and the diode looks like something hit it in front of it?i have no idea how this could happened,maybe on diode extraction?
i had this diode some months sitting and w8ting for a project,if i remember corectly i made the extraction from the sled so maybe i did something wrong.

https://s2.postimg.org/f00ylsus9/image.jpg

https://s18.postimg.org/wnc6epgex/image.jpg


That diode is a mess, it looks like you pried it out of the housing improperly, gouge marks along the edge of the aperture/can.

Window is definitely gone, maybe floating around the can, could have damaged the emitter face in the process. Could be debris on the emitter face too.

Why'd you put thermal paste on the LD itself? That's not required... With no window there that's just going to risk causing more issues, even if you had a window that could cause some issues.

Diode looks really quite beat up to me, I'd blame that for your issues (And possibly past issues too).
 
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^ Have to agree with this.^ You should never need to use thermal paste on the diode itself. If you are happy with the beam, use it until it dies and then try another extraction with hopefully gentler procedure.
 
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thanks for the quick replies i really apreciate your help.:)
i used thermal paste between diode and the housing just for better heat tranfer,some of it just came out in front of the diode when i pressed it inside the housing(generally im using thermal paste on every build i made,never had any problem with it).you suggest to not use any paste at all?i have the fear that if i dont press a diode fully it will make a good contact and will burn from temp.
about the diode i have to agree with both of you that something bad happend there but i cant do anything now,the beam looks fine and can burn staff normally so i'll use it as is and if goed 'led' sometime i'll use a replacement diode
 
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diachi

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thanks for the quick replies i really apreciate your help.:)
i used thermal paste between diode and the housing just for better heat tranfer,some of it just came out in front of the diode when i pressed it inside the housing(generally im using thermal paste on every build i made,never had any problem with it).you suggest to not use any paste at all?i have the fear that if i dont press a diode fully it will make a good contact and will burn from temp.
about the diode i have to agree with both of you that something bad happend there but i cant do anything now,the beam looks fine and can burn staff normally so i'll use it as is and if goed 'led' sometime i'll use a replacement diode


What we're saying is don't put thermal paste between the diode and the housing, it's not needed. Between housing and host, sure. Rather than worry about the diode not being pressed properly, just make sure it is pressed properly.
 

Benm

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Damn, that diode looks like it was extracted by throwing the entire drive in a blender and picking it out half an hour later :D

As for using thermal compound around the outside of the diode: if it's that beat up it's probably a good idea. If it fits in snugly it's not really required under normal circumstances, though using a -small amount- may be beneficial. If you think there is any risk of getting the compound on the output window or laser diode facet, don't bother though.
 
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i agree about the blender thing ,im still confused how this could posibly happened....

about the thermal paste,i put some before i press the diode to the housing and after the 'press' some of it just came out from the front of the diode.(i didnt put it on top of the diode in 1st place)ill leave the thermal paste there because if i try to clean it there is a risk to go to the emitter,also as thermal paste is sticky it can gather any dirt or little parts that will possibly float around the housing before they go to the emitter.at least its working for now and its a good burner for only 500ma and 3 element lense :)
 
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Yeah, I'd just continue to use it until it dies. Lesson learned about the thermal paste. Don't ever use it when pressing a diode. It is completely unnecessary.
 
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ok just an update for the info mostly.i found out that the glass was hanging inside the diode and was chaging patterns if shaked,so i wanted to try and decan it but i couldnt pull it out from the housing that was pressed without destroying it so i removed it from the front but unlucky it led'ed.....(not a big lose the diode was bad already).i had another 16x bdr that was siting and i took it apart extracted the diode carefully then replaced the old led'ed,put them everything together and WOW its working great and 3x brigher that the old messed one at 510ma :)
 




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