Numerical and experimental study on flexible films detachment towards the automation in FPCB production

Flexible electronics is one of the most promising trends in the electronics industry, with increasing implementations in several application fields. However, in industrial applications, the assembly of film-based coverlays is still performed manually, representing a bottleneck in the whole production cycle, a source of defects caused by human errors, and introducing fatiguing tasks, such as the removal of the protective film covering the base material. In a novel methodology, this latter challenge is achieved by relying on the mechanical action of a rotating tool impacting the protective film. Such a process is typically stochastic and dependent on several parameters related to the tool-coverlay interaction, and the flexibility of film-type introduces further complexity. The aim of this paper is to investigate the influence of working conditions on the reliability of the process (i.e., success rate of the removal of the protective film). Finite element method (FEM) simulations are used to investigate and assess the stiffness exhibited by the component in response to the impacting force; therefore, a favorable gripping configuration is identified. An experimental campaign of the automated process is presented, aimed at assessing the effects of process parameters (tool rotating speed, adhesive thickness, approaching speed) on the protective film detachment. The results show that the process is predominantly affected by component-specific parameters, which, in turn, are significantly dependent on material supply conditions. Finally, useful insights are drawn to optimize the process and improve the design of the gripper of the robotized workcell.