Sledgestone, in order for camera pictures be worth comparing chromaticity wise, a common reference point must be used (usually “daylight” or 6500K). If “auto” is used the device will try to detect and compensate the spectra for it to look like daylight, usually with bad results with some sources but good with others (hardware and software dependent too, of course).
The pics look good to me, at least with regards to differentiating the dedoming process turn outs.
I used to soak my LED’s in “wasbenzine”, what translates into: white-spirit; refined petrol; cleaning spirit; cleaning fluid; dry-cleaning naphta. Confused? Not really, the chemical compounds involved are seldom identical from brand to brand. Last time it took 48 hours, and I still managed to tear off the bond wires when removing the residue.
So I ordered some MEK (methyl ethyl keton) and the dome of the SST-40 came off in 2 hours, and much cleaner.
I was swapping an emitter in a bike light and one of the XP mcpcb boards I was modding I slipped while cutting with a small wheel.
long story short (after I picked it up from dropping it) it had yielded a perfectly shiny silver emitter surface that when turned on at way under driven amounts, was the most even mule of “angry blue” I had even seen. I cant even guess and what color it would have been called. 000A or light royal blue.
But just so you know if you ever need a high power blue you can start with normal yellow.
Suggestions for reasonably priced protective coating for de-domed emitters? I only tried once so far (warm gas soak with no apparent loss of phosphor) and came close to success but my hand twitched while picking off a bit of residue near a bond wire… will try again but want to have a suitable sealer here before doing so.
That would be called “blue”. 
White LEDs are just monochromatic blue LEDs that’re coated with a mixture of phosphors that emit green, yellow, red, etc. when excited by shorter-wavelength (ie, blue) light.
Less phosphor means more blue light gets out unimpeded and less blue light gets reradiated as warmer colors, hence “cool” white.
More phosphor means less blue light gets out unimpeded and more blue light gets reradiated as warmer colors, hence “warm” white.
There’s a conversion loss from blue to other colors, which is why warmer-white LEDs are less efficient than cooler-white LEDs.
Sounds like you just shaved off all the phosphors and left the nekkid blue LED undamaged.
Umm, LED Seal? LED Seal - Silicone Spray Sealant
Crap, I just ordered from ’em, should’ve gotten myself some…
Thanks. I’ve never ordered from that vendor but the price is better than I saw elsewhere. Still curious if there are any tested alternatives. For example, I’ve been wondering if a uv curing clearcoat scratch repair liquid might work. Cars parked under direct sinlight get pretty hot and the material would have to deal with the temperatures associated.
Pretty good. Decent prices, fast shipping, no complaints at all.
Miller-Stephenson (in Connecticut) sells all sorts of conformal coatings, including silicone! Ie, pull off the dome, but with thinned silicone, a thinthinthin coating can protect the nekkid chip, but still be less of a coating than a shaved LED.
Silicone, urethane, you name it. Something like 5-6 different kinds.
You can get ’em in a spray-can or also in bottles, last I recall. Quick spritz onto a disposable surface, finefinefine brush (forgot what they’re called, “baby-hair” or something weird like that) to apply right to the surface of the chip.
Wow!
Where did you get the stuff?
(shipping to NL will probably be expensive though…)
Those Green Berets much likely are due to usage of solvents with acetone (like that nitro thinner stuff).
I also keep tiny leftovers of dome substance over the bond wires but not the die, protects them.
:-)
I got it from here:
They don’t seem to ship to other countries though…
I would offer to buy it and send it to you myself, but that would be like 50€ in total…
Is shipping a bottle like that €40 (390kr) ?? 
No, but the price for shipping it to me is 20€ ~185sek. The bottle itself is only 10€, but the shipping is expensive because of hazardous material I think.
And the same is applied when shipping hazardous material to other countries. Come to think of it I’m not even sure that I’m allowed to ship it…
Okay, i see.
I forgot the shipping to your address…
Let me know if you want me to do some research if I can send it or not!
Alright, if it’s not too much work.
Update:
Forget the nitro thinner, especially the ELMA stuff, of which i’m still not sure if it actually contains toluene or not… :person_facepalming:
From Germany: Toluol analysenrein (C7H8) mind. 99,5% - 1 Liter in Braunglasflasche
From England: https://m.ebay.com/itm/Toluene-Toluol-500ml-99-9-Pure-very-High-quality-ACS-Lab-Grade-500-ml-/332123462068
I just ordered a 1 Liter bottle from Germany, €19,48 shipped.
I forgot to ask:
What did come off with the dome?
The phosphor?
Maybe pure toluene is too agressive, should be mixed with something more neutral. :person_facepalming:
Thu, 03/28/2013 - 20:52
Funny.
First mention of toluene 4½ years ago, only recently we actually try it.
Yes, the glue that held the phosphorus completely dissolved in high temperature Toluene. I don’t think you have to mix it. Even though the dome popped of in about five minutes in cold Toluene I had to leave it in for over 15 minutes to get it completely clean. So I’m not worried about that.