RFID Technology and Screen Printing

First, the definition of RFID
What is RFID? RFID is the abbreviation of Radio Frequency Identification, which is radio frequency identification, commonly known as electronic label. RFID's main core component is an electronic tag, which is only less than 2 mm in diameter. Radio waves emitted by sensors within a few centimeters to several meters distance can read the information stored in the electronic tag, and identify the items represented by the electronic tag. And the identity of the appliance.

1. The concept of RFID technology
RFID radio frequency identification (RFID) is a non-contact automatic identification technology. It automatically recognizes target objects and obtains relevant data through radio frequency signals. The identification work can work in various harsh environments without manual intervention. RFID technology can identify high-speed moving objects and can identify multiple labels at the same time, making operation quick and easy.

RFID is a breakthrough technology. First, a single, very specific object can be identified, instead of identifying only one type of object like a bar code. Second, radio frequency is used to read data from external materials, and bar codes must be read by laser. Third, multiple objects can be read at the same time, and barcodes can only be read one by one. In addition, the amount of information stored is also very large.

2. The basic composition of RFID
The most basic RFID system consists of three parts.

Tag: Composed of a coupling element and a chip, each tag has a unique electronic code and is attached to an object to identify a target object;

Reader: A device that reads tag information and can be designed to be handheld or stationary;

Antenna: Passes RF signals between tags and readers.

3. Basic working principle of RFID technology
The basic working principle of RFID technology is not complicated. After the tag enters the magnetic field, it receives the RF signal from the reader and sends the product information stored in the chip (passive tag, passive tag or passive tag) based on the energy obtained by the induced current. , Or actively send a frequency signal (ActiveTag, active tag or active tag); reader reads the information and decoded, sent to the central information system for data processing.

Second, the application of RFID technology
1. Logistics and Supply Management; 2. Manufacturing and Assembly; 3. Air Baggage Handling; 4. Mail/Express, Parcel Handling; 5. Document Tracking/Library Management; 6. Animal Identification; 7. Sports Timing; 8 Access Control/Electronic Tickets; 9. Roads are automatically charged.

Third, RFID technical standards
In general, the frequency that the RFID reader sends is called the operating frequency or carrier frequency of the RFID system. The RFID carrier frequency basically has three ranges: low frequency (30-300 kHz), high frequency (3-30 MHz), and ultra-high frequency (300 MHz-3 GHz). Common operating frequencies include low frequency 125 kHz and 134.2 kHz, high frequency 13.56 MHz, UHF 433 Mhz, 860-930 MHz, and 2.45 GHz.

Fourth, the characteristics of smart labels and screen printing technology
The printing of smart labels is very different from the printing of traditional labels. Due to the special nature of smart labels and their chips, they cannot withstand the pressure of the printing press. Therefore, in addition to ink jet printing, printing surfaces are generally used first, and then Chip layer composite, die-cutting process. The widespread application of traditional bar code labels in all walks of life, and its convenient role and certain anti-counterfeiting functions have become the consensus of people, but with people's higher production, storage and transportation, durability, anti-counterfeiting, management and many other aspects With more comprehensive information requirements, traditional bar code labels are obviously inadequate. Not only are they unable to provide information on product production, management, etc., they cannot warn about the temperature required for product quality guarantees, but also have a single, easy-to-use effect on security. Counterfeit and gradually lose the anti-counterfeiting effect of goods. With the advancement of technology and application in the field of label production, a brand-new, multi-functional, smart label with good anti-counterfeit effect has begun to be widely used. It will bring new vitality and vitality to label printing.

1. Characteristics and Applications of Smart Labels
SmartLabel is also known as a radio frequency identification tag, which is a high-tech product in the label field. Now it has played an important role in product packaging and gradually replaces traditional product labels and bar codes. Smart Label is a rookie in the field of labels. It has the function of surpassing the traditional labels and is the crystallization of high technology such as electronics and computers printed on the labels. The smart tag contains an RFID tag, a covert or public trademark protection indicator, or a sensor that indicates the status of the product. The electronic tag is mainly composed of a chip and an antenna. The chip is mainly used for receiving and transmitting data, and is read through a radio frequency signal sent by a reader. The reader is connected with an antenna and a computer network to form an electronic module, and the reader sends from it. The special signal of the antenna is given to the electronic tag in a specific area, and the feedback information is processed and transmitted to the computer network so that the management personnel can obtain the special information of the product.

Smart labels can help manufacturers and consumers understand the status of commodity inventory, circulation, and shelf life in real time, and play a significant role in monitoring the status and position of their products in the supply chain. For example, the packaging of many foods and medicines must be stored and transported at a specific temperature and in a low-pollution environment. General labels cannot understand and monitor the temperature and shelf life of products stored, and smart labels can be monitored during product storage and transportation. For temperature-sensitive, perishable product temperatures, it uses special chips, antennas, and sensors to measure the temperature during storage and transportation, alerting manufacturers to prevent temperature changes affecting the product. Also, if the warehouse manager can use smart tags to understand the type and quantity of products on the shelves, check the product inventory data to determine the product sales. In addition, smart labels improve the anti-counterfeiting effect of traditional labels, and its anti-counterfeiting capabilities have greatly exceeded traditional bar code labels, especially in pharmaceutical packaging.

The core of the smart tag is a radio frequency circuit and sensor containing an IC chip. A programmable integrated circuit and an antenna are installed inside, and a radio frequency signal and a read-write device can be used to receive and transmit information. Product identification, anti-counterfeit, and theft prevention are provided. Various functions, such as management, are currently used to upgrade and update bar code labels of products. Smart labels have the advantages of being small, thin, and flexible (product thickness can be made about 0.1 mm, size from a few millimeters to nearly 20 cm, and can be distorted and bent freely), as well as having the ability to read data quickly and can be The command reads ID numbers and some special information.

Smart tags have anti-collision and read-write features and can read and write multiple electronic tags at the same time. It can carry data, and can quickly read the data stored in its chip through a special card reader wirelessly, and can also easily overwrite its data during the work process. Smart tags can be used without connection, without power, without contact, and can also make rich changes at the radio frequency. In the smart tag, the internal characteristics and readable functions of implantable materials are widely used in the field of wireless identification, such as product identification, quality monitoring, ticketing, asset management, and providing series tracking management. Smart labels provide new tools for anti-counterfeiting and logistics management.
2. Smart Label Printing Technology
There is a big difference between the printing of smart labels and the printing of traditional labels. At present, the printing technology of traditional labels in our country has a very high level. There are many experienced companies in the trademark printing industry, and many well-designed and high-quality products are also produced. The product, but for the smart tag, some people think that it has nothing special, just use a plain label to cover it with a beautiful coat, which is not difficult for high-quality label printing companies, but simply adding The smart labels of beautiful garments are worrying because of their high added value, otherwise they will cause important losses. So what are the characteristics of smart label printing compared to traditional label printing?

First of all, from the definition of the smart tag, smart is a radio frequency circuit composed of chips, antennas, etc.; and the label is a label printed process that enables the radio frequency circuit to have a commercial outerwear. From a printing point of view, the emergence of smart labels will bring higher gold content to traditional label printing. The chip layer of the smart tag can be packaged and printed with materials such as paper, PE, PET, and even textiles to make self-adhesive stickers, paper cards, hanging labels, or other types of labels. The chip is the key to the smart label, which is determined by its special structure and cannot withstand the pressure of the printing press. Therefore, in addition to ink-jet printing, it is generally used to print the surface layer first, and then combine with the chip layer and die-cut process.

1) Printing method. Printing is primarily based on screen printing, because the quality of screen printing on integrated circuit boards, membrane switches, etc. is unmatched by other printing methods. In smart label printing, conductive inks are used, and the preferred screen for printing conductive ink is nickel foil perforated mesh. It is a kind of high-tech silk screen, instead of a wire mesh woven from general metal or nylon. It is a foil mesh drilled from nickel foil. The mesh is hexagonal and can also be made by electrolytic forming. Hole shape. The entire mesh surface is even and thin, which can greatly improve the stability and precision of imprinting. It is used to print high-tech products such as conductive inks, wafers, and integrated circuits. The effect is good. The circuit line interval of 0.1 mm can be distinguished and the positioning accuracy can be Up to 0.01 mm. You can also choose 61-100 T / mm silk screen solvent printing, printing conductive ink drying at 60 °C.

2) Application of conductive inks. Conductive ink is a kind of special ink, mainly consists of conductive filler (including metal powder, metal oxide, non-metal and other composite powders), connecting agent (mainly synthetic resin, photosensitive resin, low-melting point organic glass, etc.), additives ( Mainly dispersants, regulators, thickeners, plasticizers, lubricants, inhibitors, etc.), solvents (mainly aromatics, alcohols, ketones, esters, alcohol ethers, etc.) and other components. The ink is a kind of functional ink. There are mainly conductive inks such as carbon paste and silver paste in printing. Carbon paste ink is a liquid type thermosetting ink. It has the function of protecting copper foil and conducting current after film curing. It has good conductivity and low resistance force. It is not easy to oxidize, stable performance, acid, alkali and chemical resistance. Erosion of solvents; with strong wear resistance, anti-wear, good thermal shock resistance and so on. Silver paste ink is a one-component ink composed of ultra-fine silver powder and thermoplastic resin. It can be used on PET, PT and PVC sheets. It has strong adhesion and hiding power, can be cured at low temperature, and has controllable Conductivity and very low resistance. In addition, conductive nanometer carbon ink can be added to ink to make conductive ink, and metal powder (such as silver powder) in conductive ink can also be made into nanometer silver powder to make conductive ink. This conductive ink not only prints the film layer. Thin, uniform and smooth, excellent performance, but also can save a lot of material.

In smart label printing, conductive inks are mainly used to print RFID antennas, replacing traditional metal foils produced by foiling or etching. It has two main advantages. First of all, the traditional metal foil made by the foiling method or etching method has a complicated process and a long time for the production of the finished product. The application of the conductive ink to print the antenna is a high-speed printing method, which is efficient and fast, and is a printed antenna. The fastest and cheapest method of choice in the circuit. Today, conductive inks have begun to replace eclipses at various frequency bands.