With the rapid development of electronic design technology and manufacturing technology, electronic products are gradually developing towards high density, high functionality, light,small, and high transmission rate; In addition, with the rapid development of chip miniaturization and the increase of the number of data transmission, the working frequency of the system is higher and higher, and the application of high-frequency circuit board is more and more widely.
High frequency circuit board circuit design, structure design and process technology are the three elements of electronic product design. To become an excellent electronic product, we need not only excellent circuit design, but also good manufacturability, because good manufacturability can reduce the problems in mass production, shorten the product development progress and reduce the design cost, so as to improve the competitiveness of products. Therefore, the selection of circuit board materials by product design engineers in electronic product design is particularly important.
With the development of communication technology from 2G and 2.5G to 3G, as well as the current 4G and 5G, the data transmission throughput is getting larger and larger, the bandwidth required is getting wider and wider, and the frequency is getting higher and higher; The miniaturization of equipment is also one of the development trends in the future. Once the equipment becomes smaller, the circuit board needs to have higher heat conduction capacity and higher dielectric constant.
High frequency circuit board materials are mainly used in high-power amplifiers, base station antennas, global positioning systems, weather radars and weather satellites, as well as automotive radars and sensors.
When the working frequency of the circuit is in the RF frequency band, the range of plates that can be selected by the design engineer will be greatly reduced. Rogers RO4835 high frequency circuit board board special formula improves oxidation resistance. When used for a long time at a certain temperature, it can provide particularly stable electrical properties while maintaining the same processing advantages as FR4 thermosetting resin material.
At the same time, like RO4350B, the dielectric constant (DK) is 3.48 at 10GHz, the dielectric loss (DF) is 0.0037, and has a low z-axis coefficient of thermal expansion (CTE), ensuring the reliability of metal vias under various processing and operating conditions. The x-axis and y-axis expansion coefficients of the material are similar to those of copper and have excellent dimensional stability.
When talking about how to select high-frequency circuit board raw materials, Rogers company suggested that “the main parameters of circuit board materials are DK and DF. In the circuit boards used for high-frequency, the stability of DK value is the guarantee of plate reliability; DF value should be as small as possible to reduce signal loss. In addition, some high-frequency plates will also be used in some high-speed and large-scale data transmission systems.” It is particularly emphasized that all circuit boards of Rogers materials meet ROHS standards, and some products have been halogen-free. At the same time, she also said, “because there is no mandatory standard for the use of halogen-free plates in the country, there are not many companies in demand, but Rogers is reserving technology for future demand.
In addition, 2929 adhesive sheet is another high-performance circuit board product recently launched by Rogers company. It is a thin hydrocarbon adhesive sheet without glass red reinforcement, which can be used for high performance, high reliability and multilayer plate structure. The product has a DK of 2.9 and low DF (less than 0.003) at microwave frequency. It is very suitable for laminating multilayer boards with high-performance circuit board materials. It can be pressed with traditional flat press and vacuum chamber press. At present, it can provide thicknesses of 0.0015, 0.002 and 0.003 inches.