Optimal parameter design for chip-on-film technology using the Taguchi method

Chip on film (COF) is a new technology aggressively developed by liquid crystal display (LCD) module manufacturers. COF is a potential replacement method for tape-automated bonding (TAB) and chip-on-glass (COG) technology. COF technology has the following advantages: low power consumption, low cost, small structure, light weight and high resolution. It has become the major LCD module application. However, COF technology has several nonconforming items that should be reduced. These items include bonding misalignment, insufficient bonding strength and surface mount technology (SMT), solder joint defects, etc. The purpose of this study is to determine the optimum process parameters for COF technology improvement. An L₁₈ orthogonal array is employed to conduct the design of experiment for finding the optimum process parameters. The results show that bonding misalignment is reduced and bonding strength increased .