RFID tag packaging with anisotropically conductive adhesive

Process of interconnecting the RFID flip chip on aluminum/PET antenna substrate by anisotropically conductive adhesive (ACA) was developed to accomplish the low cost manufacturing of RFID tag inlay. Sample series were made under various bonding temperatures. Electric properties of the as-assembled inlays including contact resistance and insulation resistance, as well as their mechanical properties like pull-shear strength and chip adhesion shear strength, were measured and compared. After that, reliability tests, such as high temperature / humidity test 85 degrees C, 85% RH, 168h, high temperature store test 85 degrees C, 168h, were performed on these samples and the aforementioned properties were also retested. It was found that at the temperatures lower than 160 degrees C, cured ACA can't provide enough adhesion strength, while at the temperatures higher than 170 degrees C, the adhesion strength after reliability test decreased due to the weakening of the adhesion strength though the contact resistance is smaller. Thus the best bonding parameters of this kind of ACA for preparing the RFID tag inlay were 160 degrees C, 3N, 10 s.