What are the four main manufacturing methods for UHF and HF antennas? What are their characteristics?

The antenna manufacturing technology in the low frequency band is mainly the coil winding method. The general UHF and high frequency antenna manufacturing methods mainly include etching, electroplating, printing, and vacuum coating.

1. Etching method
First, we printed the anti-corrosion ink on the PET film covered with metal foil to protect the antenna circuit pattern from being eroded away during etching, and then baked, etched, and cleaned the antenna pattern we needed.

Advantages: The process is mature, the yield of antenna production is very high, and the performance consistency of the antenna is very good;
Disadvantages: the etching process is very slow, resulting in slow antenna production; due to the use of the subtractive process, most of the copper foil is etched away, so the cost is relatively high.
2. Printing method
The antenna pattern is printed on the P E T substrate through conductive silver paste, and then baked and cured, and the manufacturing process of the antenna is obtained.

Advantages: fast production speed, flexible production can be realized, and it can be suitable for small batch production.
Disadvantages: ①The conductivity of conductive silver paste is far inferior to that of copper foil (about 1/20 of it), and the conductor loss of the antenna is relatively large, causing the antenna efficiency to be inferior to the etching antenna; ②The conductive silver paste has poor adhesion to the PET substrate , Easy to fall off, resulting in low reliability of the antenna. ③ The recent surge in silver prices has led to a substantial increase in the cost of conductive silver paste, which has weakened its cost advantage. 3. Electroplating method
First, the antenna pattern is directly printed on the PET substrate with conductive silver paste (thicker than the printing method) or other electroplating seed layer, baked and then electroplated to thicken, so as to obtain the antenna product.

Advantages: The production speed is very fast, and the antenna conductor loss is small, so the performance of the antenna is good.
Disadvantages: The initial equipment investment is large, and it is only suitable for mass production.

4. Vacuum coating method
First, masking is printed on the PET substrate to form the reverse pattern of the RFID antenna, then the aluminum layer or copper layer is plated by vacuum coating, and finally the RFID antenna is formed through the De-masking process.

Advantages: fast production speed and relatively low cost;
Disadvantages: The deposited film is about 2μm, which is much lower than the 18μm of etching and electroplating. The performance of the antenna lies between etching and printing. The equipment for vacuum coating is about US$1 million, and the equipment investment is very large. Similar to electroplating method, suitable for mass production.

There are also attempts to print platinum-containing ink on the PET substrate to form an antenna pattern as a seed layer, and then electroless copper plating. Its advantage is that platinum-containing inks are cheaper than conductive inks. But the speed of electroless copper plating is slower and the deposition thickness is about a few microns. In addition, there is also a wiring method for high-frequency antennas, that is, the enameled wire (about 0.25mm) is passed through the ultrasonic head, and the ultrasonic head is routed according to the designed pattern; during the wiring process, the enameled wire is ultrasonically connected to the PVC substrate. The antenna performance of this method is very good, the reliability is also high, that is, the cost is more expensive than the etching method.