In MDDI and other interface protocols
In MDDI and other interface protocols, the differential pair signal must match a layer Reference plane in order for the impedance of the wiring to be controlled within a certain range. The current technology typically requires an additional layer or two of copper foil as the reference plane for FPC design, which will double the price. In the same way, adding more layers of copper foil will make the FPC thicker and lead to slippage. The performance suffers greatly, and the product’s lifespan is shortened by decreasing the number of times it uses FPC slides. Product performance will suffer if the sliding area is not impedance controlled. Edit basic structure Copper Sheet Electrolytic copper and rolled copper are the two main categories of copper foil. The typical thicknesses are 1 oz, 1/2 oz, and 1/3 oz. Substrate film: 1 mil and 1/2 mil are the two most common thicknesses. Adhesive (glue): The thickness is determined by the requirements of the client. Cover Movie Protective film for the cover: used for surface insulation. The most typical thicknesses are 1 and 1/2 mils. Adhesive (glue): The thickness is determined by the requirements of the client. Release paper is easy to work with and prevents the adhesive from sticking to anything foreign before pressing. Film for stiffening (PI Stiffener Film) Reinforcement board: This board improves the FPC’s mechanical strength and makes it easy to perform surface mounting operations. The typical thickness ranges from 3 to 9 mils. Stick (cement): The not set in stone as per client prerequisites. Before pressing, release the paper to prevent the adhesive from adhering to anything foreign. EMI is the term for an electromagnetic shielding film used to shield the circuit on the circuit board from interference from the outside.