The assembled PCB is made to insert the electric components manually or automatically. After inserting some electric elements on a PCB, the PCB is processed in the soldering process. However, there are some insertion or mounting errors in the PCB after the inserting or soldering process. The machine vision has been used to detect these errors. When a CCD camera and an X-Y positioning table in a machine vision use, it takes a high cost and long inspection time because it should move on some inspecting spots. In case workers inspect a PCB with eyes to find the errors, a result is different depending on worker's physical and mental condition. To solve these problems, we used a PC, universal serial bus (USB) hub to use several USB devices and several USB cameras that were located over the PCB and inspected whether the errors were found or not. In this study we found the fact that our system's error was lower than worker's and it took less cost than other machine vision system using the CCD camera and X-Y table.
