Low Temperature and Ultra Fine Pitch Joints Using Non-Conductive Adhesive for Flip Chip Technology

The low temperature and ultra fine pitch chip on glass (COG) bonding using non-conductive adhesive (NCA) was developed. 30 mum pitch Sn bumps on Si chip were bonded with the metal pads on the glass substrate at 80 degC. Reflowed Sn bumps were used to reduce the NCA trapping. The initial contact resistance of the bump joints at 80 MPa pressure was less than 30 mOmega, which was lower than that of the joints using anisotropy conductive film (ACF). Aging treatment at 85 degC slightly decreased the contact resistance. Failed COG joints were not observed before and after aging