The field of information technology has become an important power engine to enhance the strength of national scientific and technological innovation, promote economic and social development and improve overall competition. 5G is a new generation of basic productivity that opens a new era of industrial digitalization and the Internet of Things. Countries around the world to seize the highest point of 5G communication technology as an important strategy for national development, whether in key components, upstream material preparation or network deployment and other aspects have begun to actively layout, pre-emptive development opportunities.

The 5G New Era

Compared with traditional 4G and other communication technologies, 5G communication technology access working devices need to meet the three basic performance requirements of full spectrum access, high frequency band and even millimeter wave transmission, ultra-high broadband transmission, and its preparation materials need to have the characteristics of large-scale integration, high frequency and high spectral efficiency. For the requirements of 5G, ceramics have "innate advantages". With the gradual popularization of ceramics in the field of mobile phone functions such as fingerprint identification and wireless charging, ceramic materials have the characteristics of no signal shielding, high hardness, strong perception and excellent heat dissipation close to metal materials, which have become an important choice for mobile phone enterprises to enter the 5G era.

Microwave dielectric ceramic materials-dielectric resonators, filters

Microwave dielectric ceramics are the most popular ceramic materials in the 5G era. Microwave dielectric ceramics (MWDC) refers to ceramics that are used in microwave frequency bands (mainly UHF, SHF band, 300MHz ~ 300GHz) as dielectric materials and complete one or more functions. Microwave dielectric ceramics have excellent properties such as high dielectric constant, low microwave loss and low temperature coefficient, which can meet the requirements of miniaturization, integration, high reliability and low cost of microwave circuits. The main materials of microwave dielectric ceramics include barium oxide (BaO)-titanium dioxide (TiO2) materials, BaO-indium oxide (Ln2O3) materials, resurrection perovskite materials and lead-based perovskite materials. Microwave dielectric ceramics are widely used in microwave resonators, filters, oscillators, capacitors and microwave substrates, and are key materials for modern microwave communications such as mobile communications, satellite communications, global satellite positioning systems, Bluetooth technology and wireless local area networks. Dielectric resonators and filters are the largest microwave dielectric ceramic devices, and at present, China is the largest market for microwave dielectric resonators and filters for mobile communications. In recent years, microwave ceramic devices are developing in the direction of chip, miniaturization and even integration. At present, there are three solutions for 5G base station filters, namely small metal cavity filters, plastic filters and ceramic dielectric filters. The traditional filter is generally realized by the metal coaxial cavity, and the electromagnetic wave of different frequencies oscillates in the coaxial cavity filter, and the electromagnetic wave of the resonant frequency of the filter is retained, and the electromagnetic wave of the rest frequency is dissipated. The electromagnetic wave resonance in the ceramic dielectric filter occurs inside the dielectric material, and there is no metal cavity, so the volume is smaller than the above two filters. In the 5G era, Massive MIMO (large-scale antenna technology) has higher requirements for antenna integration, and filters need to be more miniaturized and integrated. In order to meet the relevant requirements of 5G base stations for filters, ceramic dielectric filters that are more easily miniaturized have become mainstream solutions.

In the 5G era, everything is interconnected.
ceramic substrate

In the 5G era, with the gradual development of electronic components in the direction of miniaturization, precision, high speed and high reliability, as well as the gradual increase in the use of high-power electronic components, rapid heat dissipation and reliability at extreme temperatures have become the key issues of packaging. The package substrate is an important component material of the chip package, which can be divided into organic, ceramic and composite materials. The raw material of inorganic ceramic substrate is alumina (Al2O3), aluminum nitride (AlN), silicon carbide (SiC), beryllium oxide (BeO) and other ceramic materials with high chemical stability, high corrosion resistance, good gas tightness, high thermal conductivity and matching thermal expansion coefficient. In our country, the preparation technology of ceramic materials such as Al2O3, AlN, SiC and BeO is relatively mature, and we have been able to master the thin film metallization process of ceramic surface, but there is still a lack of post-film metallization technology of ceramic surface.

semiconductor ceramic chip material

In 5G communication technology, a large number of medium and high frequency devices are required, mainly including filters, power amplifiers, low noise amplifiers, radio frequency switches, etc. Compound semiconductor materials are the core key materials for the preparation of these devices. Compound-based semiconductor materials mainly include gallium arsenide (GaAs), gallium nitride (GaN), silicon carbide (SiC) and other compound semiconductors, with large band gap, high electron mobility, direct band gap and other properties, can achieve high spectral efficiency, large frequency wave processing, low delay response and other functions. Compound semiconductor materials will be widely used in 5G, Internet of Things, smart cars and other applications in the future.

piezoelectric ceramic material

In the process of 5G communication industrialization, it will be accompanied by a large number of base station construction and terminal application. Therefore, a large number of high-frequency filters, signal transmitters and other components are required. Filtering piezoelectric materials are key materials for making these devices. The main filter piezoelectric materials include piezoelectric crystal materials, piezoelectric ceramic materials and piezoelectric thin film materials. Piezoelectric ceramic materials mainly include calcium titanium structure (barium titanate, lead zirconate titanate) materials, tungsten bronze structure materials and bismuth layered structure materials. In recent years, the global annual sales of piezoelectric materials have increased by about 15%. Since 2017, the annual global sales of piezoelectric ceramic products have reached more than US $15 billion.

The new material behind 5G mobile phones-zirconia

In recent years, smart terminal ceramics have developed rapidly and have received high attention from the market, mainly because precision ceramic materials have some excellent properties and characteristics that other smart terminal materials (such as metals and plastics) do not have, and can meet the development trend of 5G communication and wireless charging. As we enter the 5G era, because 5G communication uses wireless spectrum above 3GHz, the antenna structure of smart phones will be more complex than 4G, with larger signal transmission volume and faster transmission speed. At present, the aluminum-magnesium alloy widely used in the mobile phone shell cannot meet the requirements of 5G signal transmission due to its strong signal shielding effect, nor can it be wirelessly charged, while the ceramic material has little signal shielding, which is convenient for wireless charging, and the antenna structure is easy to design. Wireless charging technology is mainly realized by magnetic resonance, electric field coupling, magnetic induction and microwave antenna transmission technology. Since the current metal casing has shielding and absorbing effects on electromagnetic fields, which will affect the transmission efficiency of wireless charging, the wireless charging function cannot be used in metal back cover mobile phones and smart watches. However, electromagnetic waves can smoothly pass through non-metallic materials such as ceramics, glass and plastics. Therefore, to realize wireless charging function, smart phones and watches must adopt ceramic and glass back covers. Although plastics can also be used, they are easy to age and have poor texture. It can be seen that ceramic materials can better solve the signal transmission problem whether 5G communication or wireless charging. It is precisely because nano-zirconia ceramics have the advantages of wear resistance, rust resistance, non-allergic to skin, good skin affinity, comfortable to wear, and good appearance and moist feel, so it is more suitable for smart wearable devices. With the advent of the 5G commercial era, nano-ZrO2 ceramic backplane has become the best alternative material. At present, China is ahead, and more than 90% of the world's ceramic backplane is made in China.

multilayer ceramic capacitor

With the rapid development of multi-layer ceramic capacitor (MLCC) materials under the support of 5G technology, it has become an indispensable component in electronic equipment, which has a profound impact on mobile Internet communication technology and the way of information interaction in human society. it has promoted the upgrading of the Internet of things industry and strengthened the intelligent interconnection between people and people, people and things, and things and things. The development of 5G mobile communication technology has put forward higher and stricter requirements for the performance of multilayer ceramic capacitor materials. Multilayer ceramic capacitor materials will gradually develop in the direction of high frequency, low power consumption, miniaturization and high energy storage density technology to meet the arrival of the 5G era.