RFID tag antenna printing design

RFID, or Radio Frequency Identification Technology, is a non-contact automatic identification technology. It automatically identifies objects and obtains relevant data through radio frequency signals. The identification work does not require human intervention and can work in various harsh environments. With the gradual maturity of large-scale integrated circuit technology in the 1980s, the size of the RF1D system was greatly reduced, making RF1D technology into a practical stage. at the same time. The frequent appearance of various RFID tags also shows that people have entered a new stage in the research and development of RF1D tag antennas. This article will explain various printing solutions for RF1D tag antennas.

Advantages of RFID tag antenna printing method

Currently, the RF1D tag antenna has three manufacturing technologies, such as etching method, coil winding method and printing method. Compared with the etching method and coil winding method, the RF1D tag antenna printing method has the following unique advantages.

(1) The metal R FID antenna made by the traditional etching method is not only complicated in process and high in cost, but also takes a long time to manufacture the finished product, and the RFID tag antenna printed with conductive ink is efficient. And the low price is very helpful for reducing the production cost of RFID tags.

(2) Using the FOCal method to make RFID tag antennas can more accurately adjust the main technical parameters of the tags, and maximize the performance of the tags. The main technical parameters of RFlD tags are: resonance frequency, Q value and impedance. All RFID tag antenna manufacturing methods can adopt the method of changing the number of antenna turns, size and wire diameter to obtain the optimal performance of the tag. However, the RF1D tag antenna printing method can also accurately adjust the local width of the antenna and the thickness of the ink layer.

(3) As the application of RFID tags is becoming more and more widely personalized, more and more RFID tag antenna printing methods can easily change the shape according to the requirements, such as sticking to the surface of objects with different curvatures and angles to meet customer requirements without reducing Use performance.

(4) The RFID tag antenna printing method can be printed on different substrate surfaces according to user requirements, such as PVC, PET-G, PET, ABS, PC and paper-based materials. If the coil winding method is used. It is difficult to produce RFID tags that are suitable for harsh environmental conditions using materials such as PCs.

(5) With the widespread use of RFID tags, more and more IC chip manufacturers have joined the ranks of RFID chip production. Due to the lack of a unified standard, various performance parameters are also different. The printing method for making RFID tag antennas has great flexibility. Suitable for chips provided by various manufacturers. It can be matched with various chips and modules with various packaging forms to achieve the best performance.

RFID tag antenna printing technology

RFID tag antenna printing is a method of directly printing conductive lines on an insulating substrate with conductive ink to form an antenna, and is also called additive manufacturing technology.

1. Conductive ink

In recent years, the development of conductive ink has greatly promoted the application of printing technology in the production of RFID tag antennas. Conductive ink is a kind of functional ink, mainly including carbon paste and silver paste. Carbon paste conductive ink is a kind of thermosetting ink. It can protect copper foil and conduct electric current after film formation and curing. Has good conductivity and low impedance. The ink layer of the carbon paste conductive ink is not easy to be oxidized, and has the characteristics of stable performance, acid and alkali resistance, strong wear resistance, good thermal shock resistance, etc .: The silver paste conductive ink is based on ultrafine silver powder and thermoplastic resin. This kind of liquid ink can be used on PET PT, PVC and other sheets. It has strong adhesion and hiding power, can be cured at low temperature, has conductive controllability and ultra-low resistance.

It can be said that without the development of conductive inks, there is no application of printing technology in the manufacture of R FlD labels. For the built-in printed antennas of RF1D tags, a good conductive ink formulation requires good printability. The ink layer after printing has the characteristics of strong adhesion, low resistivity, low curing temperature, and stable conductivity.

2. Printing method

At present, the printing methods of RFID tag antennas have been expanded from only screen printing to offset printing, flexographic gravure printing and other printing methods. The currently more mature production process is screen printing and gravure printing technology. When selecting printing process printing, SIRF1D tag antenna, comprehensive consideration should be given to the surface performance, ink adhesion performance, cost, process and other aspects of the printing material.

(1) Screen printed RFID tag antenna

Screen printing is the preferred printing method for RFID tag antennas. This is because nickel foil perforated meshes (not meshes woven from metal or nylon) are more suitable for printing conductive inks whose meshes are hexagonal. The round hole shape can also be made by electrolytic forming. The entire mesh surface is flat and even, which can greatly improve the stability and precision of the imprint. The printing effect is better, the line interval can reach 0.1mm, and the positioning accuracy can be 0.01mm. The screen printed RFID tag antenna has the following advantages:

①This is a green environmental protection technology, which can realize one-step printing without aggressive materials. ②The conductive ink can make the printed antenna more flexible;
③The price of printing equipment is lower j
④Can print on various printing materials, and can print cross lines.

(2) Offset printing with offset RFID tag antenna has the advantages of high efficiency, high precision and high resolution, but the ink film thickness of offset printing is small, which does not meet the requirements of antenna printing.

Although this can be done by printing multiple times, it poses new challenges for register control of fine lines.

(3) Flexographic RFID tag antenna

Flexo printing can use water-based ink and uV curing ink. The resolution of flexo printing is usually around 601 / cm. Fine printing can reach 801 / cm, and the thickness of the ink film is 6-8 m. More suitable for the requirements of RFID tag antenna printing. With the development of thin plate technology, the printing accuracy of flexo printing continues to improve. However, due to the printing pressure of flexo printing, the printing plate will be deformed, so. There will be imprints on the edge of the imprint. Make the imprint on the edge of the antenna irregular. Affecting the accuracy and impedance of the antenna, it is easy to produce waste products.

(4) The resolution of gravure RFID tag antenna gravure can reach 10001 / Cm. The ink film thickness is 8 ~ 12um. But because the printing pressure is too high. There are certain difficulties when printing RF1D tag antennas.

(5) Inkjet printing RFID tags

Inkjet printing is the fastest growing printing method in recent years, and its versatility is unmatched by other printing methods. This pressureless printing method can spray the digital information in the computer directly onto any shape material. The ink system is more complicated. Water-based uV ink can be used. However, inkjet printing will have deviations in inkjet position, and small ink droplets will appear in the blank area, affecting the printing quality and producing edge effects.

Some people call the RFID industry the Chaoyang industry. RFlD labels will gradually replace traditional barcode labels. In the next few years, they will have an important impact on packaging and anti-counterfeiting printing. For the printing field. In the production of RFID tags, printing technology can be used to produce RF1D tag antennas, which brings new development opportunities to printing companies.