Assembly of flexible RFID tag inlays with anisotropic conductive paste (ACP)

Purpose - The purpose of this paper is to accomplish the low cost mass-production of flexible radio frequency identification (RFID) tag inlays. Design/methodology/approach - An anisotropic conductive paste (ACP) is prepared by mixing uniform micro-sized spherical conductive particles, latent curing agent and other additives into a thermoset epoxy resin. RFID tag inlays are assembled with the paste through flip-chip technology. The microstructural analysis of bonded joints, bond strength testing, and high-temperature and humidity aging testing are employed to evaluate the performance of the inlays. Findings - It was found that the chips are hard assembled on the antennae by the ACP. Flexible RFID tag inlays assembled using the presented method have good reliability when working under high frequency (13.56 MHz) conditions. Research limitations/implications - The method presented is a promising new way for packaging flexible RFID tag inlays with ACP. Through the use of flip-chip technology, large-scale production is possible with low manufacturing costs. Originality/value - The paper details a simple way to prepare an anisotropic conductive paste and to assemble flexible RFID tag inlays. The technique uses flip-chip technology with the paste as the electrical and mechanical interconnection material. It presents a simple and fast method of assembly for flexible RFID tag inlays on a large-scale with low cost.