【作者】 黄韬；

【导师】 胡兵；

【作者基本信息】 华中科技大学 ， 光学工程， 2012， 硕士

【摘要】 在激光软钎焊领域，传统的再流焊和波峰焊技术已不能适应集成度越来越高的微电子元器件组装的需要。研究新的钎焊方法成为印刷电路板上的元件封装亟需解决的问题。激光软钎凭借其局部加热、快速升温、快速冷却的特点能在高密度基板上形成高质量的芯片引脚焊点。在软钎焊过程中，焊点温度是影响焊接头显微组织和力学性能的关键因素。一般的温度控制器，按PID控制规律进行工作，由工程人员根据经验手动调节PID参数。但是，电路的精度会随环境而变化，这就限制了温度控制器的应用范围。为克服这一缺陷，提高控温的稳定性和准确性，使用MATLAB仿真研究了2种典型的PID参数自整定方法。针对25瓦的单光路半导体激光钎焊机，设计一种数字化温控系统，用来监控芯片引脚处的焊点温度。该系统利用单片机输出模拟电流控制激光器电源模块的工作电流，内部采用负反馈技术获取稳定的输出电流，进而控制其出光功率，用非接触式红外辐射传感器测温和采集数据。本论文在查阅大量国内外半导体激光器软钎焊温度控制系统发展概况的基础上，围绕积分分离式数字PID算法和电流串联反馈放大电路进行方案设计。实验表明该系统能快速响应温度变化，达到预期的温度值并绘制出实时曲线，被控点的稳态温度误差为0.6℃。更多还原

【Abstract】 In the field of laser soldering, traditional reflowing soldering and wave solderingtechnologies have been unable to adapt the assembling needs of increasing integration ofmicroelectronic components.That studying new soldering method for componentspackaging on printed circuit boards becomes an urgent problems to be solved.Laser soldering could produce a high quality solder joints of chip pins on the highdensity substrate from its characteristics of localized heating and the rapid rise and fall intemperature of processing regions. In the soldering process, solder temperature is a keyfactor to affect the microstructure and mechanical properties of welding heads.General temperature controller which works by PID control law is manually adjustedPID parameters by experienced engineering staff. However, the circuit precision wouldvary with the change of environment, which leads to limit the range of applications oftemperature controller. To overcome this shortcoming and improve the stability andaccuracy, two typicalself-tuning methods of PID parameters are studied by MATLABsimulation in this paper.Aiming at the newly developed25W semiconductor laser brazing machine whichemits single laser beam, a digital temperature control system is designed for monitoringand controlling temperature of solder joints of where chip pins locate in. The systemexports analog current to control the operating current of the laser power supply moduleby single-chip computer.the negative feedback technology is used to get stable outputcurrent for controlling output light power of laser within the power supply. The contactlessinfrared radiation sensor which is applied to measure the temperature and collecting data.In this paper, Basing on looking up lots of the domestic and international overview ondevelopment of laser soldering temperature control system, a scheme which centres on theintegral separation digital PID algorithm and current-series feedback amplification circuitis desingned. The experiment results indicate that the response time is very short and thesoldering temperature reaches setting value, the steady state error is only0.6℃.更多还原