FPC is abbreviation of flexible printed circuit. With the development of technology, people’s lightweight, small and portable production of digital products need to be widely used in consumer electronic digital products such as mobile phone, notebook computer, PDA, digital camera and so on. where fpc has the flexibility (free bending, folding, winding), and the characteristics of high wiring density, light weight and thin thickness are brought into full play. At the same time in the production of flexible circuit board (FPC) assembly,  the features such as short working hours, smaller volume, lighter weight, and thinner thickness than pcb are also obvious, but the drawback is also very fatal, that is, the fpc will almost have different degree of deformation during the reflow welding process, which puts higher requirements for AOI inspection systems.

 At present, the general use of AOI automatic optical inspection system is pixel contrast image processing, but the deformation of FPC is not only limited to a pixel point, this is why, AOI inspection false alarm rate is high after the reflow oven welding, the most common image contrast (pixel contrast) in the process of the FPC inspection facing the fact of the overall transformation, it means that the board that needs to be tested is different from the test standard set by programming. This difficult problem is solved by the vector analysis type AOI system. Extract the element or FPC features, vectorize to get the equation of mathematics, then calculate according to the equation whether the whole change of FPC is caused by the deformation of FPC material in welding process, the defect of the parts, or the defect of the solder joint and so on. All these problems can be automatically judged and given intelligent compensation by EKT AOI system with customized FPC fixtures.