The full name of RFID is radio frequency identification (RadioFrencyIdentity), and the Chinese translation is radio frequency identification. It is a non-contact automatic identification technology that automatically recognizes target objects and obtains relevant data through radio frequency signals. RFID tag technology has been widely used in various fields. Typical applications include: logistics and supply management, manufacturing and assembly, air baggage handling, mail/express package handling, document tracking/library management, animal identification, sports timing, access control/electronic tickets and automatic road toll collection.
The basic RFID tag system consists of three parts:
1. Tag (radio frequency card): consists of coupling components and chips. The tag contains a built-in antenna for communication with the radio frequency antenna. Each tag has a unique electronic code, which is attached to the object to identify the target object.
2. Reader: A device used to read (sometimes write) tag information, which can be designed as a handheld or fixed type.
3. Antenna: Transmit radio frequency signal between tag and reader.
RFID label printing and manufacturing method
Relying on its huge advantages, RFID technology has a huge trend to replace bar codes, but an important factor hindering its application is cost. Foreign experts pointed out that the current price of RFID tags ranges from 0.15 to 100 US dollars, which is not easy for most businesses and consumers to accept. So now many companies are committed to reducing the cost of RFID. Through the experiments of many companies, printing and fabricating conductive antennas can reduce the production cost of RFID tags, which is a major innovation of RFID. At the same time, RFID tags also bring unlimited business opportunities to the printing industry.
First of all, the easiest way to make an RFID tag is to make an integrated circuit chip, antenna, and power supply into a chip layer, and then make the bottom layer and the printed surface layer separately, and combine these three layers together. Obviously, this method of making RFID tags is easy to implement, but the cost is high and it is difficult to promote. In order to promote and apply radio frequency identification tags more widely, some new radio frequency identification label printing technologies and equipment continue to develop.
It was later discovered that RFID tags could be printed with conductive ink. Conductive ink is a printing ink that allows current to flow. Using this conductive ink, wires, circuit elements or antennas can be printed on soft or hard substrates. The printed antenna can receive the radio information stream sent by the reader. Effective experiments show that under ultra-high frequency (860MHz~950MHz) and microwave (2450MHz), the antenna printed with conductive ink has the same function as the traditional copper coil antenna. In the vicinity of 13.56MHz high frequency, adding some processing steps, such as heating or re-plating, can make the conductive ink antenna work like a copper coil antenna.
However, when printing with conductive ink, it is not only a problem of real image restoration, but also a certain printing accuracy, that is, a certain cross-sectional area. Printed circuits and circuit components must meet the requirements of the circuit. Printing with very thin ink is possible, but the printing area will be larger, which means that line printing will be wider. However, the smart label itself is in the development trend of being light, thin and small, and cannot be printed too wide. Therefore, the distance between the lines should be small, and each line must have a certain printing thickness. At present, the thickness of printed antennas at home and abroad is 0.01~0.04mm, so the effective way to print antennas is to use screen printing, and the printing thickness of the screen printer should be very uniform.