Three processes for making RFID tag antennas

In the process of wireless communication, the antenna is an indispensable component, and RFID uses radio waves to transmit information, and the generation and reception of radio waves need to be realized through the antenna. When the electronic tag enters the working area of the reader antenna, the electronic tag antenna will generate enough induced current to obtain energy to be activated.

For the RFID system, the antenna is a crucial part, which is closely related to the performance of the system.

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: etched antennas, printed antennas, coiled antennas, additive antennas, ceramic antennas, etc. The most commonly used antennas The manufacturing process is the first three.

Coil wound antenna

The manufacturing process of copper wire winding RFID tag antenna is usually completed by an automatic winding machine, that is, the insulating varnish is directly wound on the base carrier film, and the copper wire with low melting point baking varnish is used as the base material of the RFID tag antenna. , and finally mechanically fix the wire and the substrate with adhesive, and wind a certain number of turns according to different frequency requirements.

It is mostly used in low-frequency RFID systems, and high-frequency can also be used. Features: high cost, slow production speed。

Etching

The etching method is also called the etching 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 image of the antenna is also made, and the resist is printed by screen printing. On the surface of copper or aluminum, the underlying copper or aluminum is protected from corrosion, and the rest is melted by the corrosive agent.

High-frequency RFID systems are commonly used and are characterized by high precision, high cost, and low productivity.

However, due to the chemical erosion reaction used in the etching process, there are problems of long process flow and a lot of waste and waste water, which are easy to cause pollution to the environment, so the industry has been trying to find a better alternative.

Printed antenna

The antenna circuit is directly printed or printed on the substrate with special conductive ink or silver paste, and the more mature one is gravure printing or silk screen printing. Screen printing saves costs to a certain extent, but the ink uses conductive silver paste with high silver content of about 70% to obtain an antenna between 15 and 20um, which belongs to the thick film printing method, and the cost is high.

Generally used in UHF and HF RFID systems, features: large output, low cost, and low durability.