Overview of conductive adhesive interconnection technologies for LCDs

A review of current liquid crystal display (LCD) driver connection techniques is presented. Today, tape automated bonding using anisotropic conductive adhesive (ACA), is the predominant packaging approach for large area LCDs. However, there is a trend toward increasing the packaging density as well as reducing the material consumption by moving to chip-on-glass (COG) technology, which is the main emphasis of this article. This is typically done by flip-chip techniques, often with the use of adhesives. Different adhesives, including thermoplastic adhesives and thermosetting adhesives are used, with the thermosetting adhesives typically showing better long term stability and reliability. Examples of different techniques using both non conductive adhesives, ACAs and isotropic conductive adhesive (ICA) are given.