Reliability optimization for multilayer active RFID tags on rigid and flexible substrates

Radio frequency identification (RFID) is a rapidly developing technology which uses radio frequency signals for automatic identification of objects. In this paper, a novel design of an active RFID packaged on flexible film is presented. The designed ultra-high frequency (UHF) active RFID tag consists of a thin film battery, a RF chip and an antenna, which provides many advantages, including small size, light weight, and flexibility in shape. The materials and geometric structures were selected and optimized based on finite element method (FEM) simulation with considerations of the thermo-mechanical performance of the multilayer structure. Experimental results showed that there was no delamination in this flexible tag. The read range is comparable to the rigid tag, even under a 40° bending condition. A packaging method was selected to satisfy its criteria including high performance, high reliability, low cost, short producing time, low assembly temperature, and environmental friendliness. The packaging method is suitable for roll-to-roll printing technology, leading to high throughput and low manufacturing cost per unit. This research provides a systematic analysis of material selection, structure design, processing optimization, and overall reliability evaluation for UHF active RTID on flexile substrate. Not limited to active RFID tags, this method also contributes to other multilayer flexible electronic designs.