The tag inlay consists of the integrated circuit (IC), an antenna, and a substrate to hold it all together. The inlay, on its own, is a fully functional tag; ready to be packaged into either a smart label or another casing.
Integrated Chip (IC)
The IC is an electronic circuit or microchip that is manufactured at a semiconductor plant. This microchip contains a memory store and a microprocessor or decision making (logic) unit. The IC is configured either as a passively powered device (powered by inductive coupling generated from another self-powered device) or as an actively powered device (powered by a self-contained power reservoir or battery), based on the intended use of the circuit.
The antenna, which is usually a strip of conductive material (e.g. copper, aluminum) that is embedded within the substrate, is the largest component of most RFID tags and the shape—or geometry—of the tag determines the frequency at which it operates.
The substrate of an RFID is typically a thin, flexible polymer or plastic material that holds the other components of the inlay together. Another purpose of the substrate is to provide resistance to environmental factors (e.g. chemicals, moisture, temperature, impact) and to dissipate excess static charge. It's also important to consider the type of material that is used for the substrate because it could potentially affect the durability and frequency of the tag.
RFID tags are available in a wide variety of packaging, including hard cases and adhesive labels (smart labels).
Sometimes, a hard plastic or polymer is used to package the tag inlay. These type of casings are intended to provide additional protection for the tag inlay and are often made of a material such as PET, Polyacetal (POM), Polycarbonate (PC), Polypropylene (PP), ABS, Polyamide 66P (A66), and EPDM.
Smart labels are exactly what they sound like—they are smart labels (typically with an adhesive backing) with an RFID inlay embedded inside (hence the "smart" part). They come in various sizes and are commonly used for asset identification; the tag's memory will contain information such as UUID or a serial number.