Automated Optical Detector For Printed Circuit Board

Printed circuit board (PCB) are substrates for assembling electronic components. The manufacturing quality of PCB directly affects the reliability of electronic products. Therefore, PCB are known as the "mother of the modern electronics industry." With the in-depth development of electronic assembly toward higher-density, smaller-sized PCB hybrid technology, relying only on traditional functional testing and manual visual inspection and inspection methods, it has been unable to meet the needs of modern PCB industry's large-scale production. At present, the primary yield of general PCB is still hovering between 60% and 70%. In order to reduce the number of defective circuit boards that enter the next process, the demand for automatic optical inspection (AOI) key equipment in PCB inspection is required. Also getting bigger.

Recently, Zhejiang Oway Technology Co., Ltd., the first domestic manufacturer of automatic optical detection systems, adopted its own mathematical logic model and graphic image comparison technology to successfully develop an automated optical tester for printed circuit boards, which broke Israel ’s Orbotech and The monopolization of Japanese screens in this field has enabled China to enter the 30-micron era in the field of automated optical vision inspection. In the future, China's printed circuit board manufacturers will no longer have to spend expensive labor costs on manual visual mid-term inspections, and they will not have to worry about the product quality qualification rate, let alone worry about the high cost of foreign optical inspection equipment. The price is the same as foreign products That's a 50% decrease.

The automated optical inspection system uses a high-definition line scan camera to extract the surface of the PCB, and realizes the PCB surface through the technical process of digital conversion of graphics, logical determination of feature points and graphic matching, logical comparison of line shape contours, and determination and extraction of defect points. Graphical defect detection.

As the core of the entire system, how to accurately determine the defect point software and its core mathematical algorithm is the biggest problem. Traditional defect detection software uses dot matrix contrast technology (P2P). Detection requires high original image sharpness, that is, The clarity of optical image acquisition equipment determines the overall performance of the equipment, which directly results in high cost and poor performance of equipment using this type of technology, and cannot meet the requirements of leapfrog development of realistic production technology. To this end, Orwell Technology has proposed the concept of subpixel contour comparison based on six new algorithms: subpixel contour extraction, CAM data contour extraction, precise alignment algorithm, region trimming and deformation, edge registration, defect classification and filtering, and Successfully applied in new equipment. The sub-pixel contour comparison technology can optimize the quality of the original image extraction, accurately determine the edge contour of the graphic image, simplify the pixel requirements of the smallest logical determination unit, and optimize the original 50 μm collected image sharpness to an ultra-fine level of 30 microns.

The system also designed and developed an integrated high-speed linear array camera, linear encoder feedback device, ultra-high-speed flash light source, scanning imaging device with separate zoom lens PCB board; negative pressure positioning fast loading and unloading work platform; dedicated precise positioning motion control Card and a series of latest technology research results. In terms of software architecture, the operation is as simple as possible and easy to use, avoiding tedious operations and parameter debugging.

In the research and development of this product, it won 2 inventions and 4 utility model patents, 4 software copyrights, and was funded by the Small and Medium Enterprise Innovation Fund of the Ministry of Science and Technology and won the 2012 Wenzhou First Prize for Science and Technology Progress. At present, the products have been exported to Russia, India, South Korea and Taiwan and other countries and regions. In recent years, the output value has exceeded 100 million yuan.