RFIC flip-chip interconnection using a fiber type anisotropic conductive film

Recently, RFIC flip-chip mounting technique is very important to make small size and high frequency transceivers like mobile phones. The conventional flip-chip mounting uses Au stud bump bonding (SBB) and requires complicated process which includes forming and leveling of the bumps. In order to simplify the RFIC flip-chip process, we introduce a fiber type anisotropic conductive film (ACF) adhesive. This flip-chip mounting process does not require the SBB process and is suitable for transceiver system RFIC's having large number I/O pins. The interconnection between the RFIC and the substrate is confirmed by the 3D-CT images. The RF performance of the interconnection is measured and analyzed. The measured return loss of this interconnection is more than 10dB below 4.2GHz.