The Research And Realization Of Diode Laser Soldering Technique

Soft soldering is the main method used for the electronic components welding. With the tendency of industrial and consumer electronic products towards miniaturization and multifunction, together with the new requirements of green environmental protection and high reliability, it makes the connection technology of electronic components face great challenges. For small solder joints, high welding strength and narrow welding heat-affected zone, the traditional soldering process cannot meet the requirements, so the new soldering technology is emerged. In this thesis, laser soldering technology with lead-free tin-based solder for electronic components was studied, and the laser-soldering system was developed. Finally, through soldering experiments, optimal technological parameter and process method were researched.In this paper, with a view to the problems of process stability, quality reliability and technics adaptability in diode laser soldering, diode laser soldering mechanism and influence on the soldering process were deeply discussed, and the diode laser soldering system was developed, furthermore, the influence of laser power-time parameters on soldering process was studied. Firstly, functions character of laser solder was analyzed to provide a theoretical basis for laser soldering. According to the movement position of the automatic soldering system and the solder joint sites, the accurate and fast motion positioning method and the motion welding path based on interpolation were proposed. The solder feeding system was optimized on the base of analysis of the movement and the solder wire feeding mechanism to ensure the precision and smooth solder-feeding. The stable laser constant current and control system were realized based on current-voltage and current-power characteristic. Finally, through the laser soldering experiments, the soldering process and the power-time parameter were studied. Moreover, the DIP and SMD electronic components were tested to determine the soldering process and parameters.Through the research, the rapid and stable laser soldering automation system was developed, and a series of problems such as block, leakage, spraying, high temperature sintering were solved in the process of soldering. How the technological parameters influencing on soldering quality was figured out, and the reliable method of laser soldering process was puts forward.