Nichia 119's for cheap (also Cree XLAMP-7090's)

Hi,

Sorry I missed this thread. I’d be interested in 30 pieces also (U.S.), if they’re still available?

Yes, I have more. PM me for my paypal address… include your shipping address.

Are the XREs neutral or warm by chance?

PM sent…

They are XR7090WT-G1-WC-N2-H-0001

They are what Cree calls “global white”. Around 5750K, cool white. These are first generation XREs and do around 55 lumens at 350 mA, their output peaks at 75-80 lumens at around 800 mA.

Thanks for the info. I was hoping they were warmer. I have a lot of the cool white ones already.

Received my Nichia's today. Look good. I'll be using about half of them to upgrade some single and double AA and AAA lights. Thank you Texaspyro.

I'll take 20.

PM sent

What PCB are you mounting those on? I was going to use RacerR86's method here.

The only vendor I found that sells dedicated 119 boards is Led Mounting Bases

I just use thin copper sheet. It transfers heat well. Just takes a couple minutes after you've done it once:

  • Cut a copper circle that is a little smaller than 16mm. Doesn't need to be precise. Doesn't even need to be a circle.
  • Cut the disk in half and thinly pre-tin the 2 halves where the emitter will make contact.
  • Snip off a small corner of each disk for the emitter wires to come through.
  • Stick the 2 halves on a piece of Kapton tape spaced apart just a little bit.

That's it. Easier than it sounds. The Kapton tape is so thin that it doesn't seem to interfere with heat transfer. There are some flashlights (e.g. the first edition of the TN31) that have Kapton tape under the bases. I don't think it's intentional, but doesn't cause an issue below high currents.

Oh, because the base is so small and in two halves, I tape them down for the reflow. I tape across the 2 halves. The tape holds them from tilting and helps with positioning the emitter. I use thin Kapton tape for that and just cut off the excess afterwords.

Flip the base over and look to make sure the solder didn't bridge the halves. If you have a DMM, test for to make sure there is no short and that the emitter works. Just like you would do with a normal reflow.

EDIT: fixed spelling of Kapton tape.

sweet! I don’t need any right now, but I’m sure I will at some point. Paypal sent :slight_smile:

Thanks for the instructional. I just ordered a bunch of XPG/XPE PCBs from KD since they are so cheap. I'll probably just grind out the center pad but it's good to know other methods are out there too. I'll bet your method allows for better heatsinking.

I just saw a clever idea by Texaspyro in another thread. He said you may just be able to put a piece of Kapton tape over the heatsink pad on the MCPCB. That has to be the easiest way to go.

Check this site out they have some nice LEDs for cheap.

http://www.madscientisthut.com/Shopping/agora.cgi?product=Components&xm=on

I found they also have 110 Lumen 119s for 95 cents each

I soldered a few of these to SinkPads using .001” thick Kapton tape to insulate the thermal pad (I think that with the adhesive it is actually around .0015” thick). I used a .003” thick XPG solder paste stencil (with the thermal pad opening covered with tape). All of them worked fine.

I was a bit concerned that the Kapton tape might push up some and prevent the 3 mil thick solder paste layer from making contact (remember .003” is the thickness of a sheet of paper).

I think that the Kapton tape is a better way of doing it than grinding off the thermal pad… it is fairly heat conductive and does give some thermal coupling to the star… particularly with SInkpad/Noctigon stars with the direct thermal path to the star.

It should also help with regular stars to fill the gap between the thermal pad and the raised LED contact pads. One might even want to use a two or three of layers of tape with those stars.

Copper Sinkpad for 700mA emitter, really texaspyro? :slight_smile: If you have too much moolah, you can always just send them to me, I can help with proper disposal.

I also use Kapton tape + standard XPG base (aluminium - poor man’s copper), it’s just so easy and works really well. No need to bother with grinding. Just tape the top base, cut off to expose +/- section, and reflow. It can’t get any easier than that.

I run these at 700mA (2x7135) without any problem so far. No signs of current leak.

Didn’t have any aluminum ones handy…

Hi,

Can you provide a pic with the tape (before reflowing the emitter, preferably)?

Also, do you think that this (tape method) would reflow ok without stencil (but with solder paste)?

I’m wondering if the solder paste would flow UNDER the tape, onto the middle pad, during the reflow (or melt the tape)?

I think I mentioned that I have some parallel triple stars from IS that I’d like to reflow the emitters onto, but have been dreading trying to grind out the middle pad, so if the reflow works with kapton tape, and without a stencil, that’d be great.

Kapton tape was designed to tape off gold fingers on boards going through wave soldering…

Should work fine when using regular solder… maybe even better than with paste/stencil since you will have a thicker layer of solder.

Packaged arrived in good shape.

Tested a couple last night. I sanded off the middle pad on both 16mm and 8mm boards (thanks RacerR86 for the tip), reflowed with just a soldering iron, and fired them up. Very nice neutral tint! One has already gone into a Nitecore EZAA that previously had an older Cree XRE with a horrible bluish tint. The Nichia is not as bright, but the tint is much better.