ISSUES IN ASSEMBLY PROCESS OF FINE PITCH CHIP-ON-FLEX PACKAGES FOR LCD APPLICATIONS

摘要

Some of the current assembly issues of fine pitch chip-on-flex (COF) packages for LCD applications are reviewed. Traditional underfill material, anisotropic conductive adhesive (ACA) and non-conductive adhesive (NCA) are considered in conjunction with two applicable bonding methods including thermal and laser bonding. Advantages and disadvantages of each material/process combination are identified. Their applicability is further investigated to identify a process most suitable to the fine pitch packages (less than 40μm). Numerical results and subsequent testing results indicate that NCA/laser bonding process produces most reliable joint for the fine pitch packages.