New Seoul P4 LEDs

Images of new LED work.









Cooking copper discs onto the bottom of the Seoul LEDs. We made copper discs 0.030" and 0.027" thick and in the picture I added solder-paste to the copper discs and the placed the LEDs on the copper discs (burr side up). Since the copper disc is slightly larger than the slug the burr doesn't touch anything and when you glue down the led you have a small flange of the larger perimeter of the copper disc to help hold the LED down if the glue flows up and around the copper disc. I then baked the LEDs in a toaster oven to solder flow the paste and solder the copper discs to the LED slug. Adding the 0.030" copper discs raises the LED focal point to be the same as the Luxeon emitter focal point. After the LEDs cooled I added a few copper discs, flex PCBs and rigid PCBs in the photo for reference.

The two round discs in front are flex PCB double sided with the bottom having an additional layer of insulation giving it isolation. The two sided design is identical to the boards on the far right. Vias in the center stitch the center slug connection to the backside to provide thermal transfer from the slug to the bottom side.

The board at the far right is 1/32 (0.0325") thick and Aleph Light engine compatible. Since the Seoul die appears to be ~0.030" lower, raising it 0.030" makes it Luxeon emitter compatible and with this board and the Seoul LED along with the standard Aleph LE allows this to screw right into the A1, A3 light without any modifications to the reflector.