RFID Flip-Chip: Tag-it HF-I Transponder Inlays...

From Texas Instruments Reference Guide ... The Tag-it HF-I Transponder is based on the ISO 15693 standard and is fully compliant to this standard. It consists of a resonance circuit assembled on a PET foil with a flip-chip mounted microchip. An aluminium antenna is used as inductor and 2 layers Aluminium on the top and bottom side of the foil function as capacitor. The two layers are contacted with through contacts (see figure 2). TI uses this capacitor to individually tune each device to a target resonance frequency. This compensates for any material and process tolerances and so ensures optimal performance of every single transponder inlay. The trim target includes frequency offset to compensate detuning that will occur after further integration into different materials such as paper or PVC. To protect the transponder from corrosive influences, the aluminium is covered with a gravure-resist ink ...