Analysis And Optimization Research On High Speed And Precision Solder Paste Printer

With electronic components become smaller and smaller, designing and manufacturing of advanced SMT equipment has already become the urgend need for the development of precise manufacturing equipment and modern control technology, and it brings great challenge to electronic products manufacturing. The full automatic solder printer (FASP) plays an important role in SMT production line; the quality of printing will affect the follow-up process, even the produce quality. How to elevate the print precision of solder paste printer is a problem worth exploring.As one of the key components of the vision system, the camera system composed by camera, lens and light source has a significant influence on the positioning accuracy of the vision system. This paper analyzed the impact of several factors, e.g. lens distortion, perspective, changes of depth of field, to camera system, and calibrated the camera system to eliminate the influence on the positioning accuracy. In order to eliminate the influence of noise from camera and image acquisition card, image preprocessing was used to enhance quality of image. To aim at some bad reflecting situation of identification point on PCB (printed circuit board), a new curve fitting algorithm based on sub-pixel positioning was proposed to recognize identification point, and to remove optical bias from observe the identification point in upward and downward direction by CCD camera, a correction method was executed on optical system.The technologies of this paper were implemented on the full automatic solder paste printer, and the repeatability positioning precision experiment was also carryed out. The experimental result shows that the repeatability positioning precision and stability of the solder paste printer was improved and verified correctness of the method.