Polyimide Substrate Nitrogen Bonding for PCB Adhesion

The patent introduces nitrogen atoms as an intermediary substance between copper nanoparticles and the polyimide base film. These nitrogen atoms form chemical bonds with copper atoms, creating a bridging layer that prevents direct oxidation of copper while maintaining strong adhesion to the base film. The nitrogen atoms act as a protective mediator that eliminates the harmful oxidation effect.

The patent creates a composite structure consisting of copper nanoparticles, nitrogen-containing compounds, and polyimide base film. This composite material system combines the high conductivity of copper with the adhesion benefits of nitrogen-polyimide bonding, while the nitrogen layer protects against oxidation. The composite structure resolves the contradiction by integrating multiple materials with complementary properties.

The patent optimizes the concentration parameter of nitrogen atoms bonded to copper atoms within a specific range (2.6×10^18 to 7.7×10^18 atoms/m²). By precisely controlling this parameter, the patent achieves the best balance between adhesion and etching properties. Too few nitrogen atoms result in poor adhesion, while too many deteriorate etching properties. The optimal parameter range resolves the contradiction.

The patent applies partial action by introducing a controlled, limited amount of nitrogen atoms rather than excessive nitrogen content. This partial introduction of nitrogen atoms is sufficient to improve adhesion while avoiding the excessive nitrogen that would harm etching properties. The controlled partial action resolves the contradiction between adhesion improvement and etching maintenance.