help with XR-E solder points please

finally recieved my 0021 batch from cutter few mins ago.
so it should be 73.9-100.4 @ 350mA, just hope i get lucky with the tint.

also, what does the "U-bin" mean, they wrote that on the invoice. i thought the XR-E bins are refered to with "P" and "Q"?

so i have a question as this will be my first "mod".
am i right to guess that the top is where i solder -ve wire to and
buttom is where i solder +ve wire to? does is matter which side of the + i solder to?



cant wait to see how it goes in a FT-01

These are Group-codes from the XR-E binning-sheet:

(in Lumens)
N4 62.0 67.2
P2 67.2 73.9
P3 73.9 80.6
P4 80.6 87.4
Q2 87.4 93.9
Q3 93.9 100.4


Don't know if they work with "U-bin".
If you got your XR-E's from Cutter, they are P3 (min 73.9 max 80.6).

What is the exact part no. incl. bin-code ?

I read that you've already modded your FT-01 with a Cree XR-E. As for the "U",I think it stands for Uniform Small Source. It describes the LED's source pattern, such as "L" for Lambertian.

Beamshots when done please... The reflector in the FT-01 gives a real nice mix of spot and spill with a luxeon... fingers crossed for the cree.

Just to confirm these are WC colour and P3 flux

DO NOT solder wires to this led, it must be reflowed to a PCB base otherwise you risk poor performance due to thermal constraint

my original thread contains reflow instructions if you need assistance

cheers
WeLight

thermal constraint? how does that have to do with solering wires to it? You mean solder the slug to the heatsink and not thermal epoxy?? McGizmo has used epoxy and soldered wires on a few prototypes and they seem to perform quite well! Not sure after it warms up though..?

Thermal resistance is optimum when there is uniform bond between the anode/cathode and the centre thermal pad, whether it is thermal epoxy or solder paste. You want this bond to help get a path to ambient and that will be through attachment to maximum surface area, you cant get that through wire and you will never get optimal performance(ouput and life)

Hope that helps

Cheers
Wl

WeLight said:

Thermal resistance is optimum when there is uniform bond between the anode/cathode and the centre thermal pad, whether it is thermal epoxy or solder paste. You want this bond to help get a path to ambient and that will be through attachment to maximum surface area, you cant get that through wire and you will never get optimal performance(ouput and life)

Click to expand...

I think you misunderstood. Most people are planning to bond the LED to a metal heatsink using themal epoxy (while isolating the electrical contacts on the underside or just grinding them off). The electrical contact will be made by soldering wires on to the top of the LED. We weren't just going to solder wires to the top without heatsinking.

yeah, the whole bottom would be covered in thermal epoxy. So if there is added heatsinking by having the - and + pads connected thermaly underneath, they would be...