semi OT- removing plastic lens from LED

[Spehro Pefhany]

RFNA is rocket fuel (specifically an oxidizer). It's truly nasty
stuff.

It takes some pretty nasty stuff to remove epoxy. I think most folks
who want a part decapped send it out, unless they're in the business
of reverse engineering or similar stuff.



Best regards,
Spehro Pefhany

 

[Charlie E.]

Well, I'm using this red led as a light sensor. I was taking some data on response vs light intensity. (using a yellow led as a light source) And then I tried a green led (as a source) And though there were more photons I got a lot smaller signal. WTF I thought to myself, well maybe the red palstice lens is absorbing all the green light. So I filed it down and increased the signal by a factor of 5 or so... Now if I could just get more of it off...

When hitting this with a file I'm afraid I'll 'take out' the little bonding wire and that will be the end of it.

George H.

If you are close, use something more like emory cloth or other fine
sandpaper...

 

[Anthony Stewart]

5 mm LEDs use epoxy and anything that removes it chemically will be toxic. Fumes from burning epoxy are also known to be carcinogenic.

Although we know LEDs work as detectors, the efficacy is poor and spectralbandwidth is not flat.

If it is optical sensitivity you wish to measure, ie. CIE weighted eye response, then I strong recommend the Panasonic photo sensors with CIE correction. they are buffered internally and work well as current sources into resistive load to ground from a 5 V supply. You can change sensitivity with resistor load values and measure from < 1 LUX to greater than 150kLux on direct sunlight. They have a wide beamwidth , so a stepped black aperture is needed if you want to make narrow angular measurements from a distance. I have successfully used these to make an LED tester for a Goniophotometric meter for testing at 1 meter distance with stray light being blocked in the fixture design.

If you need more details, let me know what you are testing.

Tony Stewart