Inlay
GeneralA substrate carrying an RFID tag IC and antenna, typically in a thin flexible form factor ready for converting into labels or tags.
Inlay
An RFID inlay is a thin, flexible assembly consisting of an antenna and a Tag IC bonded to a substrate (typically PET film). Inlays are the fundamental building block from which finished RFID tags, smart labels, and embedded modules are manufactured.
Inlay Components
| Component | Material | Function |
|---|---|---|
| Substrate | PET film (25-50 um) | Mechanical carrier |
| Antenna | Etched aluminium or copper | RF energy capture and backscatter |
| IC | Silicon die (0.1-0.4 mm) | Data storage, modulation, logic |
| Bond | Anisotropic conductive adhesive | Electrical connection IC-to-antenna |
The antenna is typically manufactured through chemical etching of an aluminium layer on PET, though copper-based antennas offer better conductivity for demanding applications. The IC is attached to the antenna using flip-chip bonding with conductive adhesive (ACA) or ultrasonic welding -- processes that must maintain sub-millimetre alignment at production speeds of 20,000+ units per hour.
Dry Inlay vs. Wet Inlay
| Type | Adhesive | Typical Use |
|---|---|---|
| Dry inlay | None | Inserted into hard tags, cards, wristbands |
| Wet inlay | Pressure-sensitive adhesive on back | Converted into smart labels for direct application |
Wet inlays come with an adhesive layer and a release liner, ready for application or further conversion into printed labels. Dry inlays are integrated into rigid housings such as on-metal tags, laundry tags, or access cards.
Key Specifications
When selecting an inlay, engineers evaluate: tag sensitivity (typically -18 to -22 dBm for modern UHF), read range in free air and on target material, antenna dimensions (which constrain the minimum label size), supported EPC memory capacity (96 or 128 bits), and optional user memory size.
Leading inlay manufacturers include Avery Dennison (AD-229, AD-383), Smartrac (DogBone, ShortDipole), and Alien Technology (Squiggle series), each optimising antenna geometry for specific use cases.
See also: Tag IC | Smart Label | Tags
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Questions fréquemment posées
The RFID glossary is a comprehensive reference of technical terms, acronyms, and concepts used in Radio-Frequency Identification technology. It is designed for engineers, system integrators, and project managers who work with RFID and need clear definitions of terms like EPC, backscatter, anti-collision, and ISO 18000.
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