365 LED to cure NOA epoxy

Hi all,

The last post on a similar topic was ~5 years ago, so I was hoping the field has progressed since then. I am looking for a cheap UV source to cure NOA epoxy (NOA81 to be exact) in 10 sec or so. They say it peaks at 365 nm, curing power >2 mW/cm2. A 'professional' curing system (which delivers ~1 W/cm2) costs $1500. I find the latter too much, given the abundance of cheap LEDs/pointers these days.

http://www.thorlabs.de/NewGroupPage9.cfm?ObjectGroup_ID=4424

Has anyone tried cheap 365 nm LED flashlights to cure UV epoxies (they claim to output 1 W at 365 nm -- or do they consume 1W and output ~10% of that?) ? I am not sure what their spectra are (i.e. how much they actually deliver at at 365). I could stick a lens in front of the source to get a ~1 cm spot, so I can get the desired 1 W/cm2.

Or, has anyone tried laser pointers at 405 nm (smaller beams) for curing epoxies?

Cheers!

365nm LEDs work very well to cure Noa. I've used my Convoy S2+ UV many times and its probably the one I'd recommend. Its got a Nichia UV emitter and has great output. I've also got a Jaxman U1 that works very well. It uses a cheaper 3535-package UV LED but includes a bandpass filter so that there's no white light leakage, just pure UV. Neither of these are expensive lights.

Hey, thanks a lot! I ended up ordering two of these (below), looks like the LED alone costs as much as an entire flashlight, but at least it's comparable. I have optical mounts/lens tubes at the lab so I will rig it to focus the beam, and will attach it to a regulated power supply at 3.2+ V.

http://www.mouser.co.uk/ProductDeta...=sGAEpiMZZMu4Prknbu83y9etrgnft4LUcmDSH4XQJAc=

Re: 365 LED to cure NOA epoxy: WORKS!

An update: I wired together the 365 Ledengin I got from Mouser (897-LZ110UV000000). Soldering was a pain, will try to get a chip with proper leads next time. Collected the output using an f=100 mm, 25.4 dia achromat into infinity, refocused with an 200 mm achromat to get about a 1/4 in size image of the chip. The lenses were just something I had lying around. At 3.5 volts, a drop of NOA81 cures in 5 seconds, did not try shorter times. It does make my eyes tired to look at the image But it's only 5 sec, will get glasses.