Super-high interface adhesion through silver/polyimide heterojunction

Abstract

Metallized polymer film is becoming increasingly common in cutting-edge technology fields, and interface adhesion is the key factor affecting service performance. In this article, we used all-wet process to prepare Ag/Polyimide composite film with ultra-high interface adhesion (Over 25 N/cm). The influence of etching and reduction on interface adhesion was analyzed using central composite experiments and response surface methodology. Microcracks on polyimide (PI) surface were the basis for the formation of mechanical interlocks. And combined with SEM, EDS, and XPS data, the effect of Ag structure and composition on interface adhesion during reduction was summarized. The role of Ag aggregations at interface was explained, and concluded the detachment of Ag aggregations during peeling and high temperature was the main reason of failure. RFID tag, Circuit, and Cu/Ag/PI film (Resistivity: 9.3 × 10−6 Ω·cm) were made, which confirmed the compatibility and usability of Ag/PI film.

Keywords

• Flexible electronics
• Silver coating
• Polyimide
• Adhesion strength
• Central composite design