FPC Reinforcement Types
1. PI reinforcement: the tolerance can be controlled within +/- 0.03mm, with high precision and high temperature resistance (130℃-280℃). PI reinforcement thickness: 0.075mm, 0.1mm, 0.125mm, 0.15mm, 0.175mm, 0.2mm, 0.225mm, 0.25mm.
2. Steel sheet reinforcement: manual assembly is required, the process is more complicated and the cost is higher. Steel sheet reinforcement thickness: 0.1mm, 0.2mm.
3. FR4 reinforcement: If the thickness is less than 0.1mm, the tolerance can be controlled within ± 0.05mm. If the thickness is > 1.0mm, the tolerance is ±0.1mm. FR4 reinforcement thickness: 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 1.6mm.
The advantages and disadvantages of FPC stiffener are：
PI tolerance is small and not very hard;
Steel sheet is hard and stable, hand assembly and it is not easy to be reworked;
FR4 is thicker and has wider tolerances。