Reliability study of RFID flip chip assembly by isotropic conductive adhesive through computer simulation

Radio frequency identification (RFID) is quickly gaining a foothold in the identification and security industry. However, one major roadblock that prevents companies in adopting RFID technologies is its high manufacturing cost, particularly assembly cost. One approach to reduce the assembly cost is using surface mount technology. Currently anisotropic conductive adhesives (ACA) tape, isotropic conductive adhesives (ICA) and non-conductive adhesives (NCA) are being used for RFID flip chip assembly. Typically the ACA tape and NCA provide the necessary height control in the assembly. However, few literatures discuss about the possibility of using ICA as flip chip connection for different RFID product. In this work, we have developed techniques based on finite-element method. We use the full wave analysis approach that combines full wave simulator HFSS (high frequency structure simulator) with circuit simulator ADS (advanced design system) to simulate the different packaging approach and the electromagnetic effects on the transponder strap. From the results, design guideline by using low cost ICA as RFID flip chip interconnect can be obtained. The result is helpful in height control for the batch printing process for different RFID products.