Application of PEI Polyetherimide in 5G communication fiel

PEI's excellent dimensional stability, high temperature resistance, platability, and wave-transparent properties make it uniquely suited for 5G communications.

1. Optical communication

PEI material is the leading material in the field of optical communication, and is widely used in fiber optic connectors, optical transceiver module optical components.

PEI material has good infrared permeability, in the 850 ~ 1550nm optical communication band transmittance rate of 88% or more, and at the same time has a high refractive index in the temperature and humidity changes can remain constant, can withstand up to 2,000 hours of double 85 (85 ℃ / 85% humidity) harsh test; at the same time, PEI material has excellent long-term dimensional stability, to provide reliable signal transmission. Optical docking; PEI has high strength, high modulus, used to replace the metal manufacturing fiber optic connectors, adapters and other structural formation, or to replace the glass manufacturing optical transceiver module lens, can make the component structure can be optimized to simplify the manufacturing and assembly process, while maintaining the precise size, so that the cost of the final product is significantly reduced.

In addition, due to the high dimensional stability and high strength characteristics of PEI materials, as well as very good weather resistance, its application in the field of fiber optic splitter boxes or base station waterproof connectors, can meet the IP67 waterproof requirements, can significantly improve the long-term airtightness of the product and the use of reliability.

5G base station antennas use Massive MIMO (Massive Multiple Input Multiple Output) technology. Each base station uses two to three antennas (AAUs), and each antenna can have 64 to 128 channels. Board-to-board connectors are used between the antenna board and the RF board, as well as between the antenna board and the cavity filter board. As the demand for RF connectors for 5G antennas has increased dramatically, traditional mass production using thermoset materials and CNC machining has become an industry constraint.

RF connector insulators need materials to provide good dielectric properties, low and stable dielectric loss, very good mechanical properties, excellent dimensional stability to facilitate assembly, reliable mass production performance, PEI materials in the above aspects can meet the application requirements, has become the primary choice of RF connector insulator materials.

Whether for the traditional three-segment board-to-board connectors, or the latest pogo-pin design, PEI materials can meet customer needs, reflecting the PEI material in a wide temperature range of dimensional stability, dielectric stability, high mechanical strength, high fusion trace strength, temperature resistance and other aspects of the characteristics of the superiority of other engineering plastics, to provide customers with a more stable performance of the product, reduce costs.

In addition to board-to-board connectors, feeder connectors with DIN connectors to replace the metal shell, the traditional RF coaxial connector insulators and shells are also widely used PEI materials.

3.Filter

With the significant increase in the number of 5G antenna channels, as well as the integration of antennas and RRUs into AAUs, it has been reported that the weight of 5G antennas will increase by 30% to 80% compared with the weight of 4G antennas. How to reduce the weight for 5G antenna has become a topic of concern for major antenna manufacturers and base station equipment suppliers. Plasticization of metal filters has once again become the focus of major equipment manufacturers.

Filter cavity requires plastic materials with high heat-resistant temperature, and even some antenna manufacturers put forward to meet the needs of high-temperature reflow soldering process; at the same time, the material is required to have a linear coefficient of expansion to match with the metal, and with the increase in temperature to maintain a constant; with excellent plating performance to ensure that the cavity dimensional accuracy at high and low temperatures and the bonding strength of the surface plating layer, so as to ensure that the performance of the filter in the work period Stability. The metallized plastic material can pass the environmental simulation test and reliability verification, including high and low temperature cycling test, humidity and heat aging test, etc., the material will not be deformed, the plating layer will not fall off, and the mechanical properties will remain stable.

PEI material as a high glass transition temperature amorphous material, because it has a linear coefficient of thermal expansion similar to aluminum alloy, excellent heat resistance and dimensional stability, long-term reliability, low and stable dielectric loss, can be plated, and has a good metal bonding and other characteristics, reveals the cavity filter applications on other plastic materials incomparable advantages for the 5G base station antenna cavity filter units Weight reduction of up to 30% can be achieved; and injection molding process to achieve mass production, maintaining the dimensional accuracy between batches, reducing production costs.

In view of the excellent characteristics of PEI, PEI material has been widely used in 3G and 4G era for filter related parts, such as tuning screws, fly rod bases, fixing screws, etc. With the development of 5G technology, PEI material has been widely used in 5G base station antenna cavities. With the development of 5G technology, the size of the product is reduced, and the requirements for precision and mechanical properties are more stringent, so the advantages of PEI applications are becoming more and more significant.

4.Phase shifter

In the base station antenna, PEI is also widely used in the phase shifter, whether it is the dielectric chip in the dielectric phase shifter or the PCB bracket in the ring phase shifter, thanks to the PEI material in a wide range of temperatures, good stability of dimensional and dielectric properties, low dielectric loss and high mechanical strength and excellent resilience. With the gradual commercialization of 5G base stations and the pursuit of further reducing energy consumption and cost, the traditional dielectric phase shifter or ring phase shifter will have the opportunity to replace the chip phase shifter widely used in 5G massive MIMO antenna.

In summary, special engineering plastics PEI in the field of 5G, because of its relative to other engineering plastics in the heat resistance, dimensional stability, dielectric stability, and metal bonding and other aspects of the unique advantages, so it has a wide range of application prospects.