XHP70.2 dedoming pictures and VIDEO added

It can only gather some of that yellow layer?

Nice clean slices. :+1:

The way I do mine is I just take small slices with an exacto knife until the silicone is very thin. As long as the remaining silicone is as thin as possible I don’t think the surface smoothness really matters. With no bond wires to cut it is pretty hard to mess it up. So IMO there is no reason not to slice it. Then again all my lights’ LEDs are domeless (except my headlamp).

This LED sliced is definitely a potent combination of output and throw!

Thanks for the lesson Zozz. :beer:

Hey ZozzV6 did you get a chance to measure CD. of the slice and “dice”?

With dome 226125 cd
Sliced only 355500 cd
Sliced and diced ………?

My MF02 w/xhp70.2 (sliced and diced) lexel’s driver @ 8amps only did 298,XXX CD measured at 9 meters. But my variables of measuring might differ a lot from yours.

Very clean & precisely done ZozzV6!! Thank you for sharing the process & supporting pictures!!! . :+1:

This is very nice Mr. ZozzV6. May I know where you buy your metal pcb for led from? Thank you.

You only can remove fully from the edges. You don’t on the dies top. You need to keep a few tenth of mm silicone on them. That yellow phosphor makes white color of beam from a blue led under it. All white leds are blue under.

Redlyne22:
No I haven’t measured cd yet. Maybe tonight. I used to measure big lights at 5, 10, 15, 20 or like GT even 25m distances. This should be good at 15 and 20m. Smaller distance can read lower numbers.

Teacher:
Thank you!

clientequator:
I bought them from fasttech.com but those are 25mm MCPCB’s

It was MEM that talked me into trying the slice and dice, back when the XP-G3 first came out… remembered that last night. :wink:

OMG! Looking back through some pictures I found where I sliced my first quad die emitter back in April of 2015! It was a Quad XHP-50 Lucky Sun D80 build… :smiley:




I had two cool white and two warm white on hand, so I mixed the tint. Worked out pretty well and had an interesting look when off too! lol

It would get hot on two 18350’s, if I used 2 18650’s it would get blistering hot within about 15 seconds! Made something over 6000 lumens with the big cells as I recall. Don’t really remember the lumens on the small cells. The light is not longer assembled but I do have the copper disc with the 4 XHP-50’s on it still…

It wasn’t until after the XP-G3 flip chip technology came out that I started dicing the additional phosphor off the substrate. :wink:

Nice job!

Zozzv6, have you been able to run high current through yours? I sliced and diced one similar to your, cleaned it properly with surgical spirits, and put it back into my BLF GT70. It works perfectly with ramping, but on Turbo it starts burning. I immediately switch off the light and clean the black spot with surgical spirits, as the black is really on the leftover dome. It then again works on any mode less than Turbo, but what’s the point of a BLF GT70 that can’t use Turbo :smiley:

I’m guessing I sliced it too close to the die. What’s my options? Slice deeper still? Completely remove the dome, has this been done?

I run turbo in my MF02S with no problem. It is fet driven so almost same as in a GT. You need to make sure nothing dirt left on silicone. It is hard to get it off completely because phosphor has rough surface and the dome material bonded in thet surface. So you always have some leftower or cut spme phosphor too which can cause blue tint shift.

So do you recon my burning is either because of leftover residue or a rough/crumbly surface as apposed to the layer being too thin? Should I then try cutting closer in an attempt to get a flat and smooth cut?

Try to cut down the burned part and blow led with compressed air. Not your cut rough. The die surface rough and dome material diffunded in that when the led was manufactured.

Great info. I would like to duplicate your spacer. Never tried it and this would seem to be a good start. If you want to tweak the aluminum plate would you go thinner or thicker? Cree specs for the XHP70.2 (page 26) as 0.56mm for the base. Online metals has small sheets of (0.81mm / 0.032”) Too thin? Also, 1.016mm / 0.04” sheet Thanks for any help.

Go for the 1,016mm. Mine is 1mm and if the razorblade bending a little it is easy to cut in the dies. The base thickness is without the dies so they add a little and also you need to keep a thin layer silicone on dies. So 1mm is fine.

Thanks for the quick reply and recommendation. I have some single edge Schick injector blades that are thicker and stiffer that I’ll try.

Slicing is not a big deal but the edge cleaning from phosphor is a harder job. So I made a video to see better how I do the second part. Maybe tomorrow I have time to edit and upload it.

Today I achieved a very clean cut with a new razor:

You can see the dies good on this one:

This is the thickness I start dicing:

Here you can see the end result and the silicone left on the dies and on dies side. And the rough border between dies and silicone. That is why you need to leave a little silicone.

4,9V
1mA

Thanks for all info. Great pictures. Another interest of mine that has practical applications is wet shaving. And Feather Hi-Stainless Double Edge Razor Blades are widely regarded as the sharpest (see picture from my photo stacking days). Not sure that helps if that is the easy part, but I wonder if some chisel scalpel blades might be useful. SM61 or SM62 Swann Morton Expensive and hard to get though. Looking forward to updates.

I was looking for a chisel grind when I bought my scalpel and blades, purely for slicing domes. Did’nt find those and have had to learn to hold the bevel parallel to the die face. I also apply silicone to the blade so it drags less, and still I do a slice rather than push cut.