Dry Inlay
An NFC inlay without adhesive backing, used as an intermediate product for card manufacturing. Dry inlays are laminated between card body layers (PVC, PET) during the card production process.
What Is a Dry Inlay?
A dry inlaydry inlayNon-adhesive NFC inlay for card body laminationView full → is an NFC inlay without an adhesive backing, designed specifically for integration into card bodies and other products where the inlay is embedded between layers rather than applied to a surface. Unlike wet inlays, which are ready for surface application, dry inlays are intermediate components that undergo further manufacturing (lamination, molding, or encapsulation) to become finished NFC products.
Dry Inlay Construction
A dry inlay consists of three core layers:
| Layer | Material | Function |
|---|---|---|
| Top substrate | PET film (12-25 micrometers) | IC and antenna protection |
| IC + antenna | NFC chip bonded to etched or printed antenna | NFC communication circuit |
| Bottom substrate | PET film | Mechanical carrier |
The total thickness is typically 50-150 micrometers, deliberately thin to minimize the visible or tactile bump in the finished card. The substrates are selected for compatibility with the downstream lamination process: PET-G substrates for PVC card lamination, polyimide for high-temperature processes.
Primary Application: Card Manufacturing
The dominant use case for dry inlays is contactless smart card production. The card manufacturing process embeds the dry inlay between card body layers:
- Card body preparation. Multiple layers of PVC, PET-G, or polycarbonate are stacked to form the card structure.
- Inlay placement. The dry inlay is positioned in a cavity or between layers, centered on the card with the antenna coils optimally placed.
- Lamination. Heat (typically 130-160 degrees Celsius) and pressure (100-200 bar) fuse all layers together into a single rigid card.
- Finishing. The laminated card is punched to ISO 7810 dimensions (85.6 x 53.98 mm), printed, and optionally personalized.
Material Compatibility
The dry inlay must survive the lamination environment without damage:
| Parameter | Requirement | Reason |
|---|---|---|
| Temperature resistance | Up to 160 degrees Celsius | PVC/PET-G lamination temperatures |
| Pressure resistance | Up to 200 bar | Lamination press force |
| Chemical resistance | Resistant to plasticizers | PVC outgassing during lamination |
| Dimensional stability | Minimal shrinkage/expansion | Prevents antenna deformation |
The IC die is the most vulnerable component during lamination. Die thinning to 50-75 micrometers allows the die to flex under pressure rather than crack. The bonding method must also withstand thermal cycling; flip-chip bonds are generally more reliable than wire bonds under lamination conditions.
Dry Inlay vs Wet Inlay
| Feature | Dry Inlay | Wet InlayWet InlayAdhesive-backed NFC inlay ready for surface applicationView full → |
|---|---|---|
| Adhesive | None | Pressure-sensitive adhesive |
| Primary use | Card body lamination | Surface application (stickers, labels) |
| Substrate | High-temperature compatible | Standard PET |
| Thickness | 50-150 micrometers | 100-200 micrometers + adhesive |
| End products | Smart cards, key fobs | NFC stickers, shelf labels |
| Processing | Lamination, molding | Peel-and-stick |
Quality Testing
Dry inlays undergo pre-lamination testing identical to wet inlays: UID read, EEPROM verification, and RF performance sampling. Post-lamination testing is equally critical, as the lamination process can damage the IC die, break bond connections, or detune the antenna. Card manufacturers perform 100% testing after lamination, rejecting any card with reduced read range or communication failures.
Related Terms
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Perguntas frequentes
The NFC glossary is a comprehensive reference of technical terms, acronyms, and concepts used in Near Field Communication technology. It is designed for developers, product managers, and engineers who work with NFC and need clear definitions of terms like NDEF, APDU, anti-collision, and ISO 14443.
Each glossary term is cross-referenced with related NFC chips, standards, and other terms. For example, the term 'AES-128' links to chips that support AES encryption (NTAG 424 DNA, DESFire EV2/EV3), and the term 'ISO 14443' links to all chips compliant with that standard.
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