Research And Design Of Wire Welding Machine Ultrasonic Generator Based On FPGA

As demand for LED products sharp increase, LED industry and packaging technology rapidly develop and performance of the automatic wire bonders calls for higher requirements as well. Ultrasonic generator, which is the key equipment of automatic wire bonders, affects the strength of the connection and wire-efficiency directly. High stability digital ultrasonic generator ultrasonic generator becomes a hot topic today.The subject comes from the special funds LED project of Guangdong Province strategic emerging industries. My thesis of developing the new generation of automatic gold wire bonder is under the background of the cooperation between school and Dongguan Precision Machinery Co.Main works are in the following aspects:Analysis theory of wire bonders for ultrasonic generator. First, introduced ultrasonic wire bonding technology; secondly, analyze the ultrasonic transducer admittance model, the resonance characteristics and frequency tracking method; finally, synthesized signal on the principles of DDS and DDS spurious analysis.Design the ultrasonic generator hardware system according to the design Method of overall program. It Includes power supply circuit, reset circuit, crystal oscillator circuit, download circuit, DDS digital-analog conversion circuit, DDS filter amplifier circuit, signal sampling circuit, bus transceiver circuit, and signal sampling analog to digital conversion circuit.Design ultrasonic generator software system which includes a synthetic signal and digital phase-locked loop DDS. Simulate digital frequency synthesis and automatic frequency tracking.Design the PCB of the ultrasonic generator circuit. Debug software and do experimental verification.The paper applies FPGA technology, sine wave synthesized by direct digital frequency synthesis technology, and digital frequency based on zero phase difference between the voltage and current to track system. The method has characteristics like simple circuit structure, stable system experimental performance, frequency tracking quick response, and real time tracki.