The Automatic Alignment System for Laser Bonding Based on Visual Identification and Location

Abstract

Laser bonding is one of important technology for devices Micro-interconnection and encapsulation. Laser has a characteristic of focusing, which makes the temperature of irradiate region dramatically increase in a short time, while the entire sample keeps a low temperature. Therefore, laser bonding has broad application prospects in micro-welding field. However, the welding path planning and positioning for micro-area welding need to overcome the shortcoming of low accuracy via using positioning blocks during traditional welding manner. This paper develops a visual identification and location system using a CCD (charge coupled device) camera. Based on the figure captured by CCD camera, an image processing system is used to extract the position and the size of the solder by PC software LabVIEW. Combined the collected information with the process requirements, the process planning system specifies the servo motor operating parameters and laser power parameters. This system can locate and identify arbitrary rectangular frame in the CCD field of view instead of pre-setting the size and position of solder. What’s more, based on the planned parameter, the switch of laser and the laser power value can adjust to laser path, making the laser processing more flexible.