In Taiwan, printed circuit boards are second only to semiconductors in the high-tech industry , which is often accompanied by complex and sophisticated manufacturing processes.In order to ensure the quality of products, quality control is indispensable.Automatic Optical is commonly used in the high-tech industry
Inspection equipment often costs tens of millions or millions of dollars and is mostly imported from Israel, Japan or the United States.Therefore, in recent years, China has been quite active in the research and development of AOI machines and detection technology, hoping to successfully develop reliable AOI machines on its own in order to reduce production and procurement costs, and relevant technologies do not need to be made in foreign countries.
The number and density of components on the printed circuit board have been greatly increased due to the improvement of the function demand of printed circuit board and the continuous growth of manufacturing assembly and assembly technology.In order to ensure the quality of production, the previous visual inspection has been unable to meet the requirements of modern precision printed circuit boards.Therefore, at present, printed circuit board manufacturers mostly test printed circuit boards with automatic visual equipment, and then complete the final confirmation of defective products with manpower.
General non-contact automatic detection methods can be divided into  :
1. Automatic optical inspection
2. X-ray imaging
3. Ultrasonic imaging
4. Thermal imaging
The visual detection system used in PCB manufacturing can be divided into  :
1. Mask Pattern Inspection machines
2. PCB Pattern Inspection machines
3. Brilliant SMD visual inspection machines
4. The Soldering Inspection those
5. Assembled PCB visual inspection machines
This paper focuses on the detection of SMT components of printed circuit board, aiming at establishing a system that can be applied to the SMT components of printed circuit board.
In this paper, the second section introduces PCB SMT component defects classification, the third section of this institute used flaw detection method, the fourth paragraph is introduced the research development of flaw detection system and the use of equipment, and capture the actual circuit board to verify the sample image, finally puts forward the trend of further development and conclusion.