At 10:26 am on January 3, 2019, Chang'e-4 realized the first soft landing of the human probe on the back of the moon and the first relay communication between the back of the moon and the earth, opening a new chapter in human lunar exploration.

　　At 10:26 am on January 3, 2019, Chang'e-4 realized the first soft landing of the human probe on the back of the moon and the first relay communication between the lunar and the earth, opening a new chapter in human lunar exploration. Chang'e-4 successfully landed after 26 days of flight, which is inseparable from solar sensors (used for spacecraft orbital control and attitude control). As a key material for solar sensors, the radiation-resistant quartz developed by the Quartz Institute of China National Building Materials Institute Glass is an indelible contribution.
　　

　　
　　Quarz glass is known as the "crown" among glass materials. It is a glass with SiO2 as a single component, with super strong mechanical, thermal, optical and electrical properties. It plays an irreplaceable role in semiconductors, optical devices, optical communications, solar energy and other industries. High-purity quartz sand is currently the main raw material for replacing crystal ore and smelting quartz glass.

　　
　　　
　　1. Quartz glass classification
　　
　　
　　According to the different smelting processes, commercial quartz glass is mainly divided into the following four categories:

　　
　　(1) Electromelting process under vacuum air atmosphere, raw material use High-purity quartz sand (40 mesh~80 Objective). hydroxyl content is small (1ppmw~10ppmw), but relatively speaking, the content of bubbles and metal impurities is high, Al (30ppmw~100ppmw), and Na (4ppmw). The commercial product names are Infrasil, G.E.105, 201, 204.
　　
　 (2) Gas refining process, use hydrogen or other hydrogen-containing fuel and oxygen as energy to fuse quartz glass, and use high-purity quartz sand (100 mesh~200 mesh) in raw materials. During the smelting process, there is less metal pollution and less bubbles, but due to the hydrogen and oxygen atmosphere, the hydroxyl group contains 150ppmw~400ppmw. The commercial products are Herasil, Homosil, Optosil, G.E.104.
　　
　 (3) Flame hydrolysis synthesize quartz glass (CVD), and SiCl4 is sprayed into the hydrogen and oxygen flame to hydrolyze. There are basically no metal impurities, but they contain relatively high hydroxyl groups (1000ppmw) and Cl (100ppmw). Commercial product name SuprasilS, Spectrosil, Corning7940.
　　
　 (4) Synthetic quartz glass (PCVD), hydrolyzing SiCl4 in anhydrous plasma flame. Similar to the third type, the hydroxyl group is only 0.4ppmw and the Cl is 200ppmw. Commercial product name SuprasilW, SpectrosilWF, Corning7943.
　　
　　2. Characteristics of quartz glass
　　
　 (1) In terms of Thermal properties, quartz glass has good resistance to high temperature deformation and thermal vibration resistance. Its softening point (1665℃) is close to the melting point of platinum; the average linear expansion coefficient is very low (α=5.4×10-7/℃), which is only 1/10~1/20 of ordinary glass, which means it is quickly invested at high temperatures. It will not break in cold water.
　　
　 (2) In terms of chemical properties, quartz glass is extremely inactive and is a good acid-resistant material (except hydrofluoric acid ), and does not react with acid even at high temperatures. It is especially suitable for high-temperature acid-resistant combustion, cooling devices, preparation and storage devices for acid chemicals, as well as various chemical experimental glassware.
　　
　 (3) In terms of optical performance, it has good light transmittance to the entire spectrum. The optical high transmittance in the ultraviolet and infrared range is not available in optical glass and can be used as various optical devices. prism and lens; high temperature operation, reactor window; optical fiber and optoelectronic devices in the field of optical communication; leverages its high transmittance to light, coupled with high temperature stability and thermal shock resistance, making it It is widely used in the field of high-temperature lamps, such as ultraviolet lamps, infrared lamps, mercury lamps, xenon lamps, and halogen lamps.
　　
　　(4) In electrical applications, quartz glass is an excellent insulating material . The resistance value at room temperature (1016Ωm) is 100 times that of ordinary glass (1014Ωm), which is suitable for manufacturing high-frequency and high-voltage insulators that are resistant to high temperatures.
　　
　　3. Application fields of quartz glass

　　(1) Semiconductors (accounting for about 65%): quartz products are important semiconductor consumables and are used in the entire process of semiconductor processing.The silica in quartz glass has high purity and stable chemical properties. It does not react with any acid except hydrofluoric acid and phosphoric acid , which fully meets the needs of materials with high temperature resistance, strong deformation properties and inactive properties during semiconductor manufacturing. The requirements for containers such as wafer bearing and cleaning are widely used in semiconductor production processes. In addition, since quartz glass has a low refractive index and strong temperature resistance, it can meet the requirements of the mask plate for the base plate material with high optical transmittance and low thermal expansion, it is an important material for high-precision glass mask plate.
　　
　 (2) Fiber (accounting for about 14%): Quartz glass material is the main consumed material in the production of fiber prefabricated rods and fiber wire drawing. Quartz glass has extremely low refractive index, small absorbance coefficient and wide transmittance band range. As a light conduction tool transmitted on the principle of total internal reflection, optical fibers have extremely high requirements for refractive index. Therefore, quartz glass is widely used in optical fiber manufacturing. , the main products include prefabricated rods, furnace core tubes, quartz tubes, , etc.
　　
　 (3) Optics (accounting for about 10%): Components composed of quartz glass are key components in optical instruments. Transparent quartz glass has good optical properties and low refractive index, which can meet any light-transmitting band in the 185-3500mμ band range. Therefore, it can be used as both ultraviolet material for optical instruments and infrared material. The main products are spectrometer manufacturing, Infrared cameras, prisms and lenses. At the same time, quartz glass has strong thermal stability, with a value between 800 and 1000℃. Optical quartz glass is also widely used in high-altitude high-temperature photography, such as: high-temperature operation peeping window, high-precision range finder and large astronomical telescope .
　　
　 (4) Photovoltaic (accounting for about 7%): In the production and processing stages of the photovoltaic field, quartz glass product is a hard consumable. The quartz crucible made of quartz glass is generally used as a storage device for molten polysilicon material for subsequent drawing of single crystal silicon rods/polysilicon ingots. It is in the production process. main consumables. With the strong development of the new energy industry, China's photovoltaic industry has continued to grow in scale, and the market demand for natural quartz products, especially quartz crucible products, continues to expand.
　　
　（5）Electric light source (accounting for about 4%): In the field of electric light source, quartz glass electric light source products are widely used in the home, medical, transportation, entertainment and other industries. The xenon lamps used for automotive lighting, the ultraviolet sterilization lamp for sanitation and disinfection, and the metal halide lamp for entertainment venues, all use quartz glass as lighting tools.
　　
　 (6) Military Industry: In the field of aerospace, quartz glass products are the core components of spacecraft and space shuttle . Quartz glass has a low density, strong compressive resistance and good optical performance. It meets the requirements of space window materials to filter ultraviolet radiation and avoids the formation of "color centers" under high-energy ray irradiation. It is widely used in satellite and spacecraft, and is radiation-resistant. The illuminated quartz glass can effectively control the attitude of the spacecraft, and the high-strength radiation-resistant glass cover can provide effective protection for the spacecraft's solar cell energy system. In addition, quartz glass fiber has excellent thermal insulation performance and good dielectric performance. Widely used in composite materials for airborne radomes.
　　
　　4. Competitive pattern of quartz glass market

　　
　　The quartz glass market is a typical monopoly market. The quality of quartz glass is mainly affected by the preparation method and process. The leading enterprises in the industry have maintained high technical barriers. Currently, only 6 quartz glass manufacturing companies in the world have obtained TEL certification, four of which are overseas companies including Maitu, Heraeus , Kunxi, and Dongcao. Chinese companies include Philippe and Quartz Shares .
　　
　At present, the global high-end quartz glass market is mainly controlled by leading overseas companies such as Heraeus, Maitu, Tosho, Unimin, and Kunxi. These leading overseas companies have a long history and have unique technical advantages. They each have their own fields and markets. They have high added value and strong competitiveness in their long-term market cultivation. They have accumulated strong advantages in upstream and downstream industrial channel and Industrial scale advantage.Maitu is in a leading position in the fused silica industry, mainly mastering the gas refining and electrofusion methods for producing fused silica, occupying the semiconductor and optical fiber markets. Heraeus has mastered the gas refining method to prepare quartz glass technology for 117 years, and has a complete fused quartz prefabricated rod production-wire drawing process fiber industry chain, and is deeply involved in the optical fiber field. Dongcao's main business is semiconductors, and he has mastered the technology of producing molten quartz glass by hydrogen and oxygen fusing and electromelting methods, and the flame hydrolysis synthesis process to produce synthetic quartz glass, which has advantages in the semiconductor field. Kunxi is the only company in the world that masters plasma technology and has unique advantages in the semiconductor field.

　　
　　my country's quartz glass preparation technology compared with the advanced foreign technology level, there is still a big gap in high-purity, large-size quartz glass preparation, melting equipment and energy-saving control. With the growth of demand for quartz materials in high-tech industries such as electronic information and aerospace, the domestic quartz products industry has achieved significant improvements in process level and equipment manufacturing. During this period, Phillips, Quartz Co., Ltd., Yishida and Capita have emerged. A group of excellent quartz companies such as quartz.
　　
　　Philipur is the only quartz material company in China that has passed the certification of the three international semiconductor original equipment manufacturers, and one of the few manufacturers in the world that has the capacity of quartz fiber mass production capacity. It is also the only supplier in China with special quartz material qualifications with special quartz material qualifications. .
　　Quartz Co., Ltd. is one of the few companies in the world that have mass production of high-purity quartz sand, and its quartz manufacturing technology is leading in China.
　　
　　Yesda has the production capacity of large-sized, square quartz ingots and high-quality opaque quartz products.
　　
　　Cadidate Quartz is one of the few companies in China that can process supporting quartz products for 8- or 12-inch chip production lines.
　　
　　Source: CICC, Shenwan Hongyuan