The role of flex PCB stackup is to provide a structure and arrangement of layers that allows for flexibility in the circuit board.

The stackup determines the number and arrangement of layers, the thickness and type of materials used,

and the placement of conductive traces and components.

It is critical to design the stackup correctly to ensure that the flex PCB can bend and twist without damaging the circuitry or compromising its performance.

The stackup also affects the electrical properties of the circuit, such as impedance,

signal integrity, and noise.

Therefore, it is essential to consider the intended application and performance requirements when designing the flex PCB stackup.