面向电子器件平行封装的精密微电阻缝焊电源设计

Design of precision micro-resistance seam welding power for parallel packaging of electronic devices

为满足电子器件微型化对焊接能量精细化控制的要求,设计了一种高频逆变式微电阻缝焊电源,采用绝缘栅双极型晶体管IGBT模块搭建高频逆变电路,逆变频率达到10 kHz,缩短了能量输出调控时间,提高了脉冲输出频率。为提高系统运算能力,设计了基于双MCU构架的全数字化控制系统,实现了PWM(Pulse width modulation)及输出能量波形的数字化控制。文中对电源负载特性进行了分析,针对焊接过程中的分流、过熔等现象,设计了五阶段输出波形方案,提出了恒流、恒压、恒功率输出控制模式,采用模糊自适应PID智能控制算法实现了多阶段脉冲能量的稳定输出。结果表明,研制的焊接电源在使用智能控制算法进行平行封装焊接时能有效控制输出能量,具有良好的稳定性,通过对焊接电流、时间、脉冲数等参数的精确控制,可实现输出能量、波形的精准控制,同时获得美观、致密性好的鱼鳞纹焊缝,无明显缺陷。

In order to meet the requirements of the miniaturization of electronic devices for the fine control of welding energy,a high-frequency inverter type micro-resistance seam welding power source was designed.The insulated gate bipolar transistor IGBT module was used to build the high-frequency inverter circuit,and the inverter frequency reached 10 kHz,shortened the energy output regulation time,improved the pulse output frequency.To improve the computing capability of the system,a fully digital control system based on dual MCU architecture was designed to achieve digital control of PWM(Pulse width modulation)and the output energy waveform.In this paper,the load characteristics of the power supply were analyzed,and a five-stage output waveform scheme was designed for the phenomena of shunt and over-melting in the welding,and the output control modes of constant current,constant voltage and constant power were proposed,and the fuzzy adaptive PID intelligent control algorithm was used to realize the stable output of multi-stage pulse energy.The results showed that the intelligent control algorithm could effectively control the welding output energy,with good stability.Through the precise control of current,time,pulse number and other parameters,accurate control of output energy and waveform could be achieved,while beautiful,dense fish scale pattern weld was obtained with no obvious defects.