Manufacturing method of RFID antenna
Manufacturing method of RFID antenna
Antenna manufacturing technology in the low frequency band is mainly coil winding method, the general UHF and high frequency antenna manufacturing methods mainly include etching, electroplating, printing.
1. Etching method
First of all, the anti-corrosion ink is printed on the PE t film covered with metal foil to protect the antenna line pattern from being eroded in the etching process. Then the antenna pattern we need is obtained by baking, etching and cleaning.
The advantages of this method are: the process is mature, the yield of antenna production is very high, and the performance consistency of antenna is very good; but the disadvantage is: the etching process is very slow, resulting in the slow production speed of antenna; due to the use of reduction process, most of the copper foil is etched, resulting in high cost.
2. Printing method
The antenna pattern is printed on the PE t substrate by conductive silver paste, and then cured by baking, then the antenna manufacturing process is obtained. The advantages of this method are: high production speed, flexible production, and suitable for small batch production.
The disadvantages of this method are: 1) the conductivity of conductive silver paste is far less than that of copper foil (about 1 / 20), and the conductor loss of antenna is relatively large, which leads to the antenna efficiency not as good as that of etching antenna; 2) the conductive silver paste has poor adhesion to pet substrate and is easy to fall off, resulting in poor reliability of antenna. Recently, the price of silver rose sharply, which led to the increase of the cost of conductive silver paste, which weakened its cost advantage.
Firstly, the antenna pattern is printed directly on the PE t substrate with conductive silver paste (the thickness is thinner than that of printing method) or other electroplating seed layers, and then the antenna is baked and thickened. The advantages of this method are: the production speed is very fast, the antenna conductor loss is less, so the antenna performance is good. The disadvantage is: the initial equipment investment is large, and it is only suitable for mass production.
4. Vacuum coating method
Firstly, masking is printed on pet substrate to form the reverse pattern of RFID antenna, then aluminum or copper layer is plated by vacuum coating method. Finally, RFID antenna is formed by de MSK ing process.
The advantages of this method are as follows: the production speed is fast and the cost is relatively low; the disadvantage is that the deposited film is about 2 μ m, which is far lower than the 18 μ m of etching and electroplating. The performance of the antenna is between etching and printing. The equipment of vacuum coating is about 100 thousand US dollars, and the investment is very large. Similar to electroplating, it is suitable for mass production.
Some people try to print platinum ink to PE t substrate to form antenna pattern as seed layer, and then electroless copper plating. Its advantage is that platinum ink is cheaper than conductive ink. However, electroless copper plating is slower and the deposition thickness is about a few microns.
In addition, there is a wiring method for high-frequency antenna, that is, the enameled wire (about 0.25 mm) is passed through the ultrasonic head, and the ultrasonic head is wired according to the design pattern; during the wiring process, the enameled wire is connected with PVC substrate ultrasonically. The antenna performance of this method is very good, and the reliability is also high, that is, the cost is more expensive than the etching method.