Change polyimide structure and processing method can greatly reduce the optical loss:
1. Reduce the pile order and macromolecules between molecules in structure. Such as the introduction of the CF3 group in the monomer, such as the use of 6FDA, especially CF3 introduced in place of 2,2'-benzidine. Either due to the common plane of the structural damage unit that is destroying its load transfer structure, the polyimide lightens even become colorless. It can also increase the polymer solubility in common solvents such as THF, acetone, etc., and can maintain its high thermal stability.
2. Further substituted hydrogen on the aromatic ring with a fluorine reduce the absorption wavelength of useful communication.
3. Low boiling solvents, avoid high temperature ring, reducing the hole.
4. Improved processing methods to control the state of aggregation, reduce anisotropic material.
5. High purity monomers and solvents.