FPC flexible circuit boards account for a large proportion of applications in smart phones, which can meet the needs of mobile phone screens, batteries, and camera modules. In the 5G era, the emergence of multifunctional smart phone modules, radio frequency modules, folding screens, and miniaturized models are inseparable from the connection of FPC flexible circuit boards. Therefore, in the development of smart phones, the amount of FPC flexible circuit boards is also constantly improving.