The Arithmetic Research And System Design Of Measuring The Drill Hole Of Printed Circuit Board

Printed Circuit Borad (PCB) plays an important role in modern electronic equipment. It is an information carrier that integrates all kinds of electronic components and is widely applied to many fields. Along with the constant development of technology and continuous progress of industry, electronic products tend to become lighter, thinner, shorter and smaller. This makes PCB manufacture technology developing towards high-density. The PCB quality affects the capability of products directly. At present PCB quality test works are mostly completed by manual eyeballing. As the subjective factors'effects, missing and mistaken in test often happen. So it is urgent needed to take online automatic optical test into the PCB industry.This paper offers a PCB automatic test method by using optical video technology, microcomputer control technology and image process technology etc. This method put forward an operable and practical scheme to develop an efficient, steady, accurate and automatic PCB test system..This paper firstly introduced the present situation and future development of PCB test technology, then discussed PCB test technology at length in succedent three chapters. In the second chapter we analysed the composing of PCB test system, the property of equipments and part of the equipments'choosing. We put emphasis on topics as how to integrate computer visual technology, accurate machine technology, autocontrol technology and image process technology, how to solve the conflict between high definition and wide visual range, how to accomplish image automatic joint, how to implement accurate orientation of three-dimensional work flat. In the third chapter we introduced elementary principle and method of digital image process. In the fourth chapter we analysed the characters of system composing, primary flow of software system, arithmetic of the hole center's orientation and the hole diameter's obtaining, arithmetic of the final data error analysis. At last experimental datas proved the practical arithmetic using image process technology in this paper can make accurate test on the precision of PCB hole drilling and hole diameter. This showed the method have credible stability and practicability.