Application Research Of Machine Vision Technology On PCB V-Incision Machine

PCB is an important and basic component of electronic product. With the development ofelectronic industry, a single PCB is smaller and smaller. Usually some PCBs of same specificationare put together to process and incised to yield conveniently after they are finished. So the lastworking procedure is to V-incise the PCB, namely to incise the piece PCB from the PCB. Forarrangement of image combination is compact and incision is from double sides and it should beleveled strictly, orientation precision must be very high. At the same time amounts of PCB andhigh-speed make it difficult for mankind to realize incise precisely, which becomes a bottleneck ofPCB manufacture. The PCB incision machine is strongly needed but there is a blank in our countryon the application research about the machine vision technology applied on PCB incision equipment.This article is a pre-research sponsored by Chongqing University NC., to make machine visiontechnology applied on PCB V-incision machine.According to the orientation precision, the article designs the machine vision system hardwareof PCB V-incision machine, presents the project of lamp house based on large field illuminationinfluence of PCB image and discusses the matching problem among CCD camera, optics lens andImage Acquisition.High orientation precision makes a pels correspond very little length of real PCB so that a PCBmust be divided to some areas and shot separately. The article brings out the methods of imagecombination to ensure that there is no shoot loss and how to deal with the image superposition.Orientation sign is different according to different PCB, so it is a key question for acquisition ofstandard template when template-matching method is used to identify the orientation sign. Thedissertation emphasizes the acquisition method of standard template to shoot a limited areacontaining the orientation sign and adopts quadrature-keeping method to choose threshold andbinarize the image and also brings forward some methods to quicken the search such as to search inrestrict area and to search by two matching such as to search in restrict area and two times matching.The position of PCB on workbench is ascertained according to the matching result, the articlegives out the computational formula of coordinate transformation to adjust the incision toolprecisely.The result of template matching experiment adopted the acquisition method of standardtemplate and some arithmetic quicken the search speed is good, which proves the validity of thearithmetic.In every procedure of PCB manufacture there is similar orientation request and the researchmay extend to silk-screen and SMT equipments, in which machine vision detection system has awide application foreground.