A Flexible Printed Circuit Board (FPCB) is a type of printed circuit board primarily made from polymer films such as polyimide [1]. Compared to traditional PCBs, FPCBs offer advantages such as flexibility, bendability, ease of transmission, and lower overall cost. The subject of this study is a conductive film for a laptop keyboard, which is a flexible circuit board made from PET film (polyethylene terephthalate) as the base material. It boasts numerous advantages including high flexibility, light weight, good conductivity, cost-effectiveness, and environmental friendliness. FPCBs are widely used in control automation, smart electronic devices, modern medical equipment, consumer electronics, and telecommunications [2], as shown in Figure 1.1. Particularly in terms of cost, FPCBs are only half the price of ordinary rigid PCBs, which can significantly reduce product costs. As electronic components trend towards miniaturization and circuit board designs become more complex, flexible circuit boards, primarily made from polyimide films, have seen significant development and are widely used in various fields such as aerospace and military communications. As circuit boards evolve towards higher wiring density, the demands on inspection technology are also increasing. The object of study in this paper is a conductive film for a laptop keyboard, with a width of 450mm and a height of 680mm, indicating a large format. Compared to traditional PCBs, FPCBs have denser wiring and are prone to twisting and deformation during the manufacturing process, making their