Inner line

The copper foil substrate is first cut into sizes suitable for processing and production. Before pressing the substrate film, it is usually necessary to first roughen the copper foil on the board surface using methods such as brush grinding and micro etching, and then attach the dry film photoresist tightly to it at appropriate temperature and pressure. Send the substrate with dry film photoresist applied to the UV exposure machine for exposure. The photoresist will undergo a polymerization reaction in the transparent area of the film after being irradiated by UV, and the circuit image on the film will be transferred to the dry film photoresist on the board surface. After tearing off the protective film on the film surface, first develop and remove the non illuminated area on the film surface with sodium carbonate aqueous solution, and then use a mixed solution of hydrogen peroxide to corrode and remove the exposed copper foil, forming a circuit. Finally, use a light oxidized sodium water solution to remove the dry film photoresist that has been successfully removed.