Abstract
Chip on Glass (COG) technology is widely used to mount driver ICs on Liquid Crystal Display (LCD) substrates. We have developed Resin Core Bump technology as a novel COG technology. Unlike conventional COG bonding with Anisotropic Conductive Film (ACF), Resin Core Bump structures form stable interconnections by direct contact between the bump and the substrate. Moreover, the bump and its bonding structures are optimized to achieve a fine-pitch interconnection. In this paper, we report the results of our evaluation of the fine pitch bondability and interconnection reliability of Resin Core Bumps using 20 μm-pitch test samples. Reliability was evaluated by a Thermal Cycle Test and Thermal Humidity Bias Test. The initial contact resistance was even more stable than with a 40 μm conventional COG structure. The maximum resistance increment was less than 2.0 Ω after 2000 cycles.
