ERSO’s COF with non-conductive interconnection process

High pin-count and reliability promised for LCD driversThe Electronics Research & Service Organization (ERSO) of ITRI has successfully developed a non-conductive film interconnection process for Chip-on-Flex (COF) technology used in LCD (liquid crystal display) modules. Capable of reducing the size of an interconnecting pitch down to 30mm, the process is expected to achieve high pin-count, integrate more functions into LCD driver ICs, cut material cost, and decrease overall product size as well.Conventionally, Chip on Glass (COG) and Tape Automated Bonding (TAB) have been two major thrusts of packaging methods adopted by small to large sized LCD products alike. With the principal advantages of increased I/O density, increased number of active/passive drivers, superior electrical and thermal performance and improved reliability, Chip-on-Flex (COF) packaging technology, is now gaining its popularity among high-end LCD driver ICs.While the IC industry has been aggressively pursuing nano-scaled manufacturing and packaging technologies, a much higher pin-count resulted from a reduced interconnecting pitch size is becoming even more significant to ever decreased die sizes. With the interconnecting pitch down to 30mm, the pin-count in a 10.9 mm x 2.9 mm test chip, for example, can reach 623. In addition, fabricated on a flex substrate so as to reduce the total volume of LCD driver IC package, ERSO COF with non-conductive adhesive is ideal for portable electronic devices demanding lightweight, thinness, full color and high resolution. Today’s thriving market for personal products such as mobile phones, palm-size digital devices, and digital cameras provides great opportunities for commercial applications using this new innovation.ERSO plans to transfer this promising technology to local companies for mass production. With the first technology for non-conductive films interconnection process in Taiwan, it is anticipated that LCD panel and module companies can significantly improve the quality and competitiveness of their products.