Design And Implementing Of The Machine Vision System In RFID Tag Package Equipments

Radio frequency identification is a kind of automatic identification technology which has been in rapid development in the last few years. Compared with other auto-id technologies, RFID can acquire data and transmit it without the involvement of personnel. RFID system also has other advantages such as larger data memory, longer life time, tolerance of bad environment, and longer accessing distance. RFID can be used in many different areas, such as asset tracking, manufacturing, supply chain management, retailing, payment systems, security and access control. Nowadays the price of tags poses a great barrier to the wide application of RFID, so it is of great importance to develop RFID tag package equipments with high performance/price ratio.This thesis discusses the design and implementing of the three sets of machine vision systems respectively used in the dispensing module, flipping module and mounting module in the RFID tag package equipment. The discussion of the design and implementing of machine vision systems in the thesis involves three points: the choosing of components, the mechanical design and the software development. The principle and the implementing method of image processing techniques such as image calibration, coordinate calibration and imaging locating are discussed in the thesis. A wafer scanning method based on the information extracted from die images is proposed to meet the requirement of automatic wafer feeding and die picking in the flipping module. A hybrid lighting technique composed of direct lighting and darkfield lighting is proposed after summarizing common lighting techniques and fully analyzing the characters of dies in the wafer. With the hybrid lighting technique, the vision system can acquire die images with high quality. A multiple reflector vision system scheme is proposed after analyzing the advantages and disadvantages of double camera scheme, double stationary reflector scheme and retractable reflector scheme in the mounting module.This thesis proposes a new vision on-the-fly system based on the beam splitting lens to meet the demand of component picking and placing in the electronic manufacturing equipments. The system utilizes only one camera, and could collect the images of the component and the mounting place successively or simultaneously which are then used to align the component and the mounting place. The image collection and alignment could be carried out while the picker is moving to the mounting place. The system could improve the efficiency and the stability of the equipment sufficiently, and is simple enough for implementing in the engineering.