At present, according to the differences in antenna wire material, material structure and manufacturing process, RFID tag antennas can be roughly divided into the following categories: etching antennas, printed antennas, wire-wound antennas, additive antennas, ceramic antennas, etc., the most commonly used antennas The manufacturing process is the first three.
The etching method is also called the engraving etching method. First, a layer of copper or aluminum with a thickness of about 20mm is covered on a base carrier, and a screen printing plate of the positive antenna image is made, and the resist is printed by screen printing. On the surface of copper or aluminum, the copper or aluminum below is protected from corrosion, and the rest is melted by the corrosive agent.
However, since the etching process uses a chemical attack reaction, there are problems such as a long process flow, a lot of waste and wastewater, and it is easy to cause pollution to the environment. Therefore, the industry has been working hard to find a better alternative.
Directly print or print the antenna circuit on the substrate with special conductive ink or silver paste, and the more mature method is gravure printing or silk screen printing. Screen printing saves costs to a certain extent, but its ink uses conductive silver paste with a high silver content of about 70%, and the antenna between 15 and 20um is obtained, which belongs to the thick film printing method and the cost is high.
Coil Wound Antenna
The manufacturing process of copper wire winding RFID tag antenna is usually completed by automatic winding machine, that is, it is directly wound on the base carrier film and coated with insulating varnish, and the copper wire with low melting point baking varnish is used as the base material of RFID tag antenna , and finally mechanically fix the wire and the substrate with an adhesive, and wind a certain number of turns according to different frequency requirements.