RFID antenna

UV curable flexo ink for RFID antennas Radio frequency identification (RFID) devices and contactless smart cards are capable of uniquely identifying an individual or object when they are interrogated by an external radio frequency signal. Recently, a process of printing with the use of UV curable conductive flexo inks has been introduced. The inks are based on polyfunctional acrylates with silver flakes added for the electrical conductivity. The advantages of these inks are ... 

RFID antennas (for HF short-range systems, unlimited in UHF range)... 

Screen Printing Established technology and major ink for printed electronics today. Inexpensive capital equipment. Low price inks. Can be expensive due to amount of material required relative to yields. Mainly in RFID antennas and PV front electrodes. Feature resolution 75 microns. 

Solution processable conductors come in three main elasses metals, metal oxides or organics. Printed metals, most notably as eleetrodes or RFID antennae, are mainly obtained by using partiele-based inks. Silver or gold partiele inks are eommercially available. Evonik has developed silver printing pastes, sueh as Silver 30 SN, a formulation of silver flakes in organie solvents, optimized for screen printing (Figure 2.6). 

Curing time after printing is in the order of seeonds in a hot air drier. Sheet resistanee of a 25 pm thick film is lower than 14 mf2, giving a eonduetivity suffieient for RFID antennae (Figure 2.7). 

Figure 2.7 Printed RFID-antenna. (see Colour plates p. LI)...

A Radio Frequency Identification (RFID) antenna was placed in the central unit to detect when items are removed, flashing up a warning on a touch screen when the stock is incomplete. This also facilitates the restocking process as the technology can display exactly what is missing, and the expiry date. 

XINK Laboratories, another supplier, can offer lexographically printed RFID antennae using a proprietary silver ink which cures at ambient temperature. The company s materials are printable in a single pass on to a range of heat-sensitive substrates such as PET and paper as well as those used in pharmaceutical packaging for example. PolylC directly prints the RFID circuitry on to standard polyester foil using organic semiconductors and insulators to build up the necessary transistors. 

Embroidered RFID antennas for tire-tracking applications... 

Early generation RFID antennas were produced by chemically etching aluminum or copper foils and laminating them with polymer films ranging in thickness from 18-35 microns. However, today antennas are typically printed on polymer base substrates using conductive inks, an inexpensive and cost-effective way for different radio frequency waves to be received. Since the label typically requires opacity, a white carrier and facestock material, such as a paper stock, are used. An adhesive is applied to the carrier with a formulation designed to provide transportation-secure adhesion to the surface to which the RFID label is to be mounted. 

MID antennas have become mainstream in recent years, and nowhere more so than in the mobile-communications sector. Units of this kind are manufactured in very high numbers in Asia. Molex announced the production of its twenty millionth LPKF-LDS antenna [76] back in 2009, and a large proportion of MID antennas are two-shot moldings. The sector is further expanding to include tablet PCs, with demand leaning more toward larger antenna structures. RFID antennas for very widely varying applications constitute yet another sector. 

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