Surface mountable low cost packaging for RFID device

Abstract

Radio frequency identification (RFID) is quickly gaining a foothold in the identification and security industry. It is used in areas of healthcare, cashless ticketing system, inventory management and security identification. However one critical roadblock that prevents companies in adopting RFID technologies is the manufacturing cost with assembly cost as the main contributing factor. One approach to reduce the assembly cost is using surface mount technology. Currently anisotropic conductive adhesives (ACA) and non-conductive adhesives (NCA) are being used for RFID flip chip assembly. However these two approaches only permit series assembly which result in higher assembly time as compared to surface mount device using ICA which allows batch screen printing. Isotropic conductive adhesives (ICA) joints however have a more sensitive affect from moisture and mechanical stress. Therefore in this paper, ultra-violet (UV) epoxy was used to encapsulate the chip that had been surface mounted onto the substrate so as to increase the mechanical strength of the ICA and also to reduce the exposure to moisture which degrades the joints. Epoxy that needed only UV curing offered additional benefit of its quick curing characteristic. Two test vehicles, daisy chain sample and active circuitry chip, were fabricated and mounted on polymer substrate. Both vehicles performed well in reliability tests and active tests on detection distance