Selective Cu patterning on polyimide using UV surface treatment and electroless plating

Needs for an inexpensive and simple technology for fabricating fine copper (Cu) patterns on a polyimide (PI) film have been increasing. In this study, vacuum-UV induced surfactant masking (VISM) process was proposed as a tool for simplifying selective electroless Cu plating. The electroless Cu plating process using VISM is capable of Cu patterning on solvent-soluble siloxane-modified polyimide (PI) without photoresist patterning steps unlike conventional electroless Cu plating process. The relation between the wettability of SBC-PI film surface and the UV/Ozone treatment time was investigated to establish VISM process condition. The feasibility of the proposed process was verified by demonstrating the fabrication of Cu/PI patterns with widths ranging from 5 μm to 50 μm and measuring an electric property of some patterns.