Osram Oslon 3rd Gen 6500k tested in Courui D01, Plus De-Doming trials.

Scalpel cut at strategic places like dome base should alow better fluid entry and faster working time.
Gas or hot gas is not same. Hot gas (de doming possible in less than 10 minutes :slight_smile: )

So I really strongly believe it can and it could work. Right paint thinner is even more capable than gas and no need for isopropyl alcohol bath after de doming. Gentle compressed air blow and finished :wink:

Would something like Prepsol possibly work better? It may not be as harsh as petrol.

Didn’t think of prep-sol. I’ll add it to the list.

i went thru a period whrere i went on a “mad de-doming spree”… i mean, other than the obvious candidates, like XMLs ?? i did a nichia, an XBD… lol

the nichia was whatever one has 5 dots, arranged like a “# 5” on a dice…

ugly when dedomed in my 68 clone the nichia came in… left the other 68 untouched, liked it better.

=

let it soak in gasoline, as long as it takes… dont be impatient. manual force to hurry it up only runs ris of breakng stuff… after letting it soak for as long as it takes? i use the spray “electronics cleaner” to drive off little bits… the kind that evaporates instantly.

let the gasoline do the work, keep your mitts off of it, lol…

Try slicing /carving the bulk of the silicone off first, then HOT GAS it! :smiley:

Today was "Round 2" of the Osram Oslon 3rd Gen De-Doming trials.

It was a long day, full of fumes, danger, trial & error. Again, there were five lucky candidates, but unlike last time, all of them are still working after the de-dome.

I started the day by purchasing a spare fire extinguisher, as I had planned to add some heat into the equation today, along with some Prep-Sol, Thinners, & Petrol.

Here are the five candidates laid out prior to starting;

And here is the test setup I used. Hot air re-flow station, with tip removed;

I had no idea how it would perform, but at least it was adjustable, & there was no naked flame....

Test #1 was the Prep-Sol (Preparation Solvent), which is generally used to wipe down a surface directly before applying paint to it. The LED was not altered/cut, & was immersed into the hot liquid.

In it goes;

The setup worked very well - I was able to quickly bring it to the boil. There was also a little turbulence as a result of the boiling. I monitored it with an IR thermometer, & kept it around the 120 DegC mark.

I kept it in there for an hour, & periodically removed it to check progress. After ~15 mins, I noticed one side of the dome had separated. The dome appeared to open up gradually, like a clam-shell, but never fully separated. I had to top up the fluid several times, & ended up boiling off around 200ml.

I decided to put it aside, keeping it in the fluid, & move on to test #2.

Test #2; Enamel Paint Thinners.

This was probably the most likely to go up in flames...

The second unmodified LED was boiled for over three hours in the thinners, with periodic checks, & many top-ups. I went through about 700ml in this test.

Similar to #1, the dome separated early, but never came completely off. I was tempted to give it a prod, but I kept hearing "keep your mitts off of it" in the back of my mind....

After three hours, it was clear that it was not coming off by it's self. I could see that the dome had completely separated from the phosphor over the die & bond wires, but was still attached to one edge.

During this time, I decided to put LED #1 into the thinners as well, so it ended up being in for 1.5 hours.

Both LED's were in the same "Clam shell" state, so I carefully removed the dome off the last edge of them both;

LED #1 & dome;

Ignoring the left-over phosphor around the perimeter, it came out fairly well.

LED #2 & dome;

Not so good; a large patch of phosphor is stuck to the dome. This was not done by me removing the dome - it had already occurred during separation in the fluid.

Test #3; Petrol.

The unmodified LED was submersed in the boiling petrol, & after ~5mins, the dome was starting to lift at the edge.

It was in for a total of only 14mins until the "Clam" had opened, again leaving the dome attached at just one edge.

Here's how it looked;

Again, some phosphor has stuck to the dome during the separation process in the petrol.

Test #4; Powered LED in room temperature petrol.

This is the method that I hinted at in a previous post; Applying power to the LED whilst submersed in petrol.

Here's the setup prior to adding the petrol;

Cell used is a Samsung ICR 28A @ 4.0v.

The plan was to observe it using the auto-darkening welding mask.

This was a little intimidating - I really didn't know what to expect when I hit the power button....

The LED lit up, & within a few seconds, there were bubbles coming from the dome. I cycled it a few times, & checked it, but there was no apparent change yet.

When I was pretty sure it was not going to explode, I grabbed a photo through the welding mask;

After that, I let it run for a while, when all of a sudden it let out a 'pop'! I had my finger on the button, so let it off immediately.

I regained a little composure, & inspected the LED - there was a black bubble in the center, but it did not look like the dome had been breached.

The LED still worked, but I figured it was toast, so I put it back in, & this time hooked up a 25R to it. It bubbled away again, a little more vigorously this time. I realized that with the low voltage of these LED's, I had applied too much power initially.

When I was taking pictures after all the testing, I noticed that this one had turned from black to grey, so I decided to flick off the dome;

There was a crater inside the dome, but the phosphor was still surprisingly in tact, albeit a little burnt, possibly from being over-driven?

Test #5; Powered LED with dome perimeter cut, in boiling Prep-Sol.

Last test of the day, & I wanted to combine the best results so far. I used the Prep-Sol, as it appeared to have the cleanest result so-far, & I carefully used a razor around the perimeter of the dome, cutting in from the edge.

This time, I used a weaker battery, @ 3.65v.

The dome lifted, & "Clam shelled" as before, but still refused to come off completely by it's self.

This is probably the 2nd best effort, with #1 being the best of the bunch.

I'll install at least #1 into the Courui test mule, to see what the numbers are.

In the first round, I almost hit 400KCd, so maybe will be better this time. I'm not sure what can be expected in this setup out of the "new" XP-G2, but I'm guessing it's less than that, so already we may have a new thrower "king" by default.

The hurdle to overcome here, is that the phosphor is stuck to the dome almost as well as it is to the die.

I still have another five of these emitters, so will "sleep on it" for a while, before going in for the 3rd round...

:beer:

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Update; Installed LED #1 into the Courui, & after a bit of fiddling with shims, it was able to produce 410KCd.

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So much effort and patience. Thank you for doing this.

Thank you very much for doing this… This Osram is hard nut to crack :slight_smile:

Please if you have some spare emitters try your .032” washer method… It looks promising… Worth another try…

Nice work. The fumes would have added a nice aroma to the work area. Good luck with the testing.

No more fooling around. Just go straight at that dome with a blow torch.

Great experimentation, lots of unlucky failures but you already found a great performance, well done. The prize is a new king of throw!! :partying_face:

djozz is one I would never argue with. I’m glad this is going to turn out ok and is a terrific win for FmC.
Tell me you have never been wrong before djozz. :sunglasses:

Lol - I don’t know about a terrific win, but thanks for the well wishes.

So far, the problem is repeatability. The guys who are building lots of lights are not going to dive in & buy a reel of these for a lot of hastle & a 1 in 5 hit rate.

Anyone try to shave one yet?

You can’t shave right down to the phosfor because the bond wires are sticking out. I tried shaving down to exactly the bond wires, and the performance was not good.

Update; Installed LED #1 into the Courui, & after a bit of fiddling with shims, it was able to produce 410KCd.

The other issue with this emitter is finding the correct cell to use in conjunction with the FET drivers, to avoid over current when the cell is full.

A centering ring that fits would be nice as well… :slight_smile:

Well done. May I ask what a dedomed XPG2 was and I guess you will take pics tonight?

The best I saw in the exact same light was 440KCd from the XP-G2 S4 2B.

As for the beamshots, I think I have about the same ratio of bad to good as I had in the OP with the dedoming…

410 vs 440 is very promising, only 7% less! With the unregular die shape of the dedomed Square, is the beam much affected in the Courui?

White-wall hunting in low modes, it has the two ‘eyes’, but real world use, it’s a nice hotspot. I’ll try to get a decent photo.