RFID Technology and Screen Printing (I)

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 tags. RFID's main core component is an electronic tag, which is less than 2mm 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 radio frequency identification technology


RFID radio frequency identification is a non-contact automatic identification technology. It automatically identifies 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. The operation is 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 components of RFID

The most basic RFID system consists of three parts:

Tag: It consists of a coupling element and a chip. Each tag has a unique electronic code and is attached to the object to identify the 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, the 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) according to the energy obtained by the induced current. , Or actively send a signal of a certain frequency (Active Tag, active tag or active tag); the reader reads the information and decodes it, and sends it to the central information system for data processing.


Second, the application of RFID technology


1. Logistics and Supply Management 2. Manufacturing and Assembly 3. Airline Baggage Handling 4. Mail/Express Parcel Handling 5. Document Tracking/Library Management 6. Animal ID Identification 7. Sports Timing 8. Access Control/Electronic Tickets 9. Automatic road charging

Third, RFID technology standards

Usually, 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 kHz to 300 kHz), high frequency (3 MHz to 30 MHz), and ultra-high frequency (300 MHz to 3 GHz). Common operating frequencies include low frequency 125kHz and 134.2kHz, high frequency 13.56MHz, UHF 433Mhz, 860MHz to 930MHz, and 2.45GHz. $Page break $

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, the characteristics of smart labels and applications


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. Smart tags include RFID tags, concealed or exposed trademark protection indicators, or sensors that indicate 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. The smart label has the advantages of being small, thin, and flexible (the thickness of the produced product can reach about 0.1mm, the size is from a few millimeters to nearly twenty centimeters, and can be freely twisted and bent), and the reading data information is fast and can be easily obtained. Special commands read 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, implantable materials of various internal characteristics and readable functions are widely used in the field of wireless identification, such as product identification, quality monitoring, ticketing, asset management, and providing a series of tracking management. Smart labels provide new tools for anti-counterfeiting and logistics management.


2. Screen Printing Technology of Smart Labels


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 smart labels 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 the first choice for screen printing, because the screen printing of integrated circuit boards, membrane switches and other aspects of the printing quality 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 wire mesh. It is not a wire mesh woven from general metal or nylon wire, but a foil mesh drilled from nickel foil. The mesh is hexagonal and can also be formed 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 effective for printing high-tech products such as conductive inks, wafers, and integrated circuits, and can resolve circuit line intervals of 0.1 mm and have high positioning accuracy. 0.01mm. You can also choose 61-100T/cm silk screen solvent printing, printing conductive ink using 60 degrees temperature drying.


(2) The application of conductive ink. Conductive ink is a kind of special ink. It can add conductive carrier to UV ink, flexographic water-based ink or special offset ink to make the ink conductive. Conductive inks are mainly composed of conductive fillers (including metal powders, metal oxides, non-metals, and other composite powders), linkers (mainly synthetic resins, photosensitive resins, low-melting-point organic glass, etc.), additives (mainly dispersants, and adjustments). Agents, thickeners, plasticizers, lubricants, inhibitors, etc.), solvents (mainly aromatics, alcohols, ketones, esters, alcohol ethers, etc.). 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 and uniform 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 etched antennas at various frequency bands, such as ultra-high frequency bands (860 to 950 MHz) and microwave frequency bands (2450 MHz). Antennas printed with conductive ink can be compared to traditionally etched copper antennas. In addition, conductive inks It is also used to print sensors and circuit prints in smart labels. Secondly, metal foils fabricated using conventional foiling or etching methods consume wasted metal materials at a relatively high cost, while the cost of raw materials for conductive inks is lower than that of conventional metal antennas. This has a great impact on reducing the production costs of smart labels. significance.