Eco-friendly adhesive materials
The IMECAT project has developed interconnection materials, such as lead-free solders and adhesives for assembly technologies of electronic systems. The new environmentally compatible technology concerns isotropic conductive adhesives (ICAs) and non conductive adhesives (NCAs). These materials can be exploited in numerous fields including automotive, LCD, telecom systems, smart card/smart label and portable telecommunication applications. With the emphasis on advanced flip-chip technologies, innovative, very fast curing NCA materials were generated. Having tested several epoxy materials such as resins and curing agents, a bisphenolic and a cycloaliphatic resin as well as a cationic curing agent were found to be most promising. These were further explored to assess their capabilities regarding their interaction with system components as well as their suitability for application. The adhesive developed for the NCA system, namely the NCA4-020, displayed a very fast curing time at about 180°C-200°C. The system allows a fast connection of flip chips on different substrates, including chip-on-flexible (COF) chromium on glass (COG) substrates. In comparison to anisotropic conductive adhesive technology, it is less expensive while it may be employed in similar applications. Work is underway to further decrease its cost in high volume production applications of smart labels. Producers of smart cards, smart labels and LCDs are sought for further collaborations.