AOI in EMS
As outsource to EMS,the requirement for Automated Optical Inspection (AOI) equipment changes as well. Due to
the diversity of the business,EMS providers require equipment that can handle a myriad of different components.
The need for frequent programming,program portability and repeatability,and the establishment of common
equipment platform become more important than before. To understand the capability of current AOI technology,
equipment from four manufacturers were installed at a test site for a post-reflow benchmark test. Two test vehicles
were used for eight different tests. Test results were recorded and analyzed. Each machine was rated for its
performance in each individual test. The result shows that no single machine outperforms others in every category.
The best performance from each category is,99.89% portability for general SMT components,99.95% for small
chips,99.16% for program repeatability,84% defect detection rate,and 28-second inspection cycle time for
motherboard type assembly. Angle measurement was performed on three machines. The model with best
performance reported the measurement within 1° difference. Based on the overall test results,AOI can be
considered an efficient tool for catching post reflow defect and improving process yield. As the renovation continues
in AOI technology during the past few years,we should expect to see an increase in AOI implementation in the
EMS industry.