WE HAVE A NEED TO BOND SOME LOW TEMPERATURE LED'S TO A THIN CIRCUIT BOARD LAMINATED TO A HEAT SINK. HAS ANYONE USED AN ULTRASONIC WELDER TO WELD COPPER GUL WING LEADS TO A COPPER PAD USING ULTRASONICS? IF NOT HAS ANYONE USED RESISTANCE SPOT WELDING FOR COPPER TO COPPER? PLEASE RESPOND VIA E-MAIL TO HAROLD.LICHT@SIEMENS.COM