Development and error compensation of laser soldering system

Purpose - Accurate alignment is vital to acquire high-quality joints with less negative effects on the rest parts of the chip or other components on a board. The purpose of this paper is to develop an integrated laser soldering system, which is accurate, compact, and flexible. Design/methodology/approach - The system combines an X-Y stage, a computer vision module and a laser module. It would automatically sense the soldering pads with computer vision, fulfill the alignment of laser beam and soldering pads together with the motion system, and finish the soldering work with laser power. Findings - Based on the analysis of experimental data, it is found that lens distortion and assembly angular errors of the X-Y stage play a distinct role on the alignment errors. Originality/value - The paper proposes an algorithm based on straight line method to reduce image distortion, and a compensation algorithm on the angular errors of the X-Y positioning stage. Experimental results show that the overall precision is satisfied for fine pitch applications and the system performs well.