Research On The Technology Of Ultrasonic Assisted Thermocompression Micro Welding For Enameled Wire

Enameled wire has been widely used in the field of aerospace, automobile making and electron components as a part or the conductive medium between each other. In these applications, traditional connection methods, take welding quality, welding efficiency and welding cost for example, are often unable to balance multiple aspects to obtain comprehensive benefits. This makes connection for enameled wire have always been one of big industrial problems for a long time.According to the difficulties of enameled wire micro welding technology, we raise the ultrasonic assisted thermocompression micro welding process based on the current thermocompression technology and ultrasonic wire bonding process, which refer to the technology of ultrasonic heat pressing on gold ball bonding. This welding process can realize the directly and reliable connection of the enameled wire and the metal without the need of remove the insulating film enameled wire surface,.Firstly, we design and build the platform of the ultrasonic assisted thermocompression micro welding, which can realize the enameled wire welding. The whole equipment includes the design of the servo pressure institution, ultrasonic vibration system; selecting the power of heat supply and self hot head design; design of the touch screen-PLC timing control system.Secondly taking advantage of the test platform for welding enameled wire, we successfully realized the connection between enameled wire (diameter is0.2mm) and phosphorus copper foil (thickness is0.2mm) with different timing control system by orthogonal experiment, and finally we get the best welding parameters; Then we take the research the impact of welding current, ultrasonic power, ultrasonic vibration time, welding time and welding pressure on tensile strength and appearance quality of welding spot through the single factor test.Finally, we analyze the welding mechanism through the metallographic examination, thermal infrared imager on the maximum temperature of the micro welding joint analysis, combined with the ultrasonic bonding theory, effects of material deformation, the bond interface metal atom diffusion mechanism and theoretical basis of formation. During the welding process, there is no metal melting in the joint area. So the technology of he ultrasonic assisted thermocompression micro welding is a solid-state welding method. Ultrasonic as a powerful energy input, which can significantly improve the quality of the enameled wire welding.