discount jewelry displays wholesale The principle and application of melt bubble growth of high -quality sapphire

Wilma

November 9, 2022 at 3:00 am

real wholesale jewelry Sun Guangnian Yu Xudong Shen Caiqing
The first author of the author: Sun Guangnian, the first and second members of the China Treasure Association Artificial Gem Committee, the third deputy chairman of the third session, the head of the crystal material factory of the Junhua Group of Zhejiang Province.
. Introduction
Puctual science is one of the three pillars (energy, information, materials) of modern civilization and is the material foundation of human civilization. Crystal growth belongs to the scientific category of materials and is the forefront of its development. Industry has proven that the development of some high -tech science and technology is closely related to crystal materials; the development of military industry, such as missiles, drones, submarines, artificial satellites and spacecraft materials. The quality of these materials determines the level of technical level, and only in terms of materials, can we hope that related technology can break through. High -quality colorless sapphire is very widely used because of its special excellent performance. For example, sapphire single crystal has a unique and excellent physical chemical properties, especially in the 0.2 to 5.0 μm bands. In infrared military equipment, satellite and space technology. Due to the characteristics of sapphire crystal electronics insulation and constant dielectric constants, it has become one of the most widely used substrate materials. To this end, countries around the world are trying to do research and production. After years of hard work, the Crystal Material Factory of Juhua Junhua Group Corporation has produced high -quality colorless sapphires with melting bubble method and melt Tirara. It can be used not only for the window materials of the military industry, but also for the energy -saving and environmental protection industry of substrate materials and light -emitting diode (LED), which has unlimited potential and development prospects.
. High -quality sapphire crystal growth technology is brief
sapphire is a type of gemstone. Except for red ruby, other Jade gems are called sapphire. Colorless sapphire is one of the sapphires. The chemical composition is tritenurtide (Al2O3), a three -party crystal system, a polished surface mask bright glass luster to Agin Kong, one axis crystal negative light, the refractive index value is 1.762 ～ 1.770 The dual refractive index is 0.008 ～ 0.010, the hardness of Mobi is 9, and the density is about 4.00g/cm3.
The artificial synthesis method of sapphire mainly includes flame melting method, melting agent and melting method. The melt method includes several methods. However, neither the flame melting method and the melting agent method cannot grow high -quality sapphire large crystals. The reason is that in addition to the slightly small crystals growing gemstone crystals, the crystals also have a large amount of inlaid structure and poor quality. The gemstone growing in the melting method is also very small, and it contains the help of the melting cation, and the quality is not very good. Only the gemstone growing gemstone growing in the melt method has the characteristics of high purity and integrity, and a single crystal can become a high -quality gemstone crystal that is urgently needed by the modern high -tech and national defense industry. The principle of melt -growth gemstone is: Put the raw materials that constitute the gem component in high temperature resistance, heat and melt, and then cool down by cooling the melt under control conditions, thereby making the crystal grow. Due to the different control conditions of cooling, the method of growing high -quality gemstone crystals from the melt is slightly different. At present, the main melt method of high-quality sapphire crystal growth technology in the world has the following four types: ① melt crystal ticker method; ② EFG (Edge-Defined Film-Fed Growth) melt method; ③HEM (Heat Exchange Method) Following thermal exchange method; ④ METHOD melt bubble method. The above four methods of growing gemstone crystals from the melt, the technical characteristics and advantages and disadvantages are briefly introduced below.
1. The melting crystal tiramine
The melting crystal bira (referred to as the melting Tirafa) is the method of using the seed crystal to grow from the melt to the crystal. This method can grow large and unsuccessful high -quality single crystals in the short term. It was first invented by J. Claston (J.) in 1917, so it is also known as the Chicolaski Law. La Fa is one of the most commonly used methods for growth crystals in the melt. Its main technical characteristics are the common foundation of all the use of Tirafa -growth crystals. The brief description is as follows: put the raw materials of the gem component in the pupa and heated it to the melting point of the raw material. The melt; there is a lifting rod that can rotate and lifts above the pupa. The lower end of the pole has a chip with a seed crystal, which reduces the lifting rod, the seed crystal is inserted into the melt, the temperature is adjusted, and the seeds are adjusted to make the seeds make the seeds. Jing neither melted nor grows up, and then slowly lifted and rotated the seed crystal rod slowly. At the same time, slowly reduce heating power, and through the entire process of growth of neck -shoulder -expanded -such as diameter -equivalent, you can obtain the required diameter crystal. The entire growth device is placed in a closed jacket to make the atmosphere and pressure in the growth environment; the windows of the outer cover can be observed through the window of the outer cover. The principle of growth is shown in Figure 1. The main advantage of this method is: ① It can easily observe the growth of the crystal during the growth process; ② the crystal grows on the surface of the melt, and does not contact the 坩埚Parasitic nucleus; ③ can easily use directional seed crystals and "neck shrinking" process. The error of the seed crystal after "shrinking the neck" can be greatly reduced, so that the crystal that can grow after expanding shoulder is reduced, and its position is reduced and the crystals with high integrity are obtained. The main disadvantage of this method is that the crystals are relatively small, and it can reach up to 2 to 3 inches in diameter
1 inch = 25.4mm. , Cannot adapt to the requirements of modern high -tech and defense industry on large -sized crystals. In the growth of large -sized crystals, the other three methods are better than the melt crystal raising method.
The 1970s, due to the needs of laser materials research, my country began to develop artificial pupaed aluminum gigar (YAG) and artificial raviometer (GGG) crystal melt growth technology. Due to the development of the military industry Need to study and apply with cutting -edge science and technology, the gemstone crystal technology of the melting Tirafa has been further developed and improved. Now it has been able to grow smoothly. Colorless sapphire, synthetic ruby, artificial pupae pillar (YAG), artificial pimyotoma (GGG), synthetic stones, etc.
Figure 1 Following the growth schematic diagram of the grid crystal growth
FIG. 2 Figure 2 Mel is sapphire crystal
Figure 3 Laser crystals growing in melt Tirafa
2. The body guidance method
The melt model method is the improved melt crystal lifting method, which can control the shape of the crystal. Its main technical features are: placing an inert mold of a high melting point in the melt, the upper surface of the mold has a "pattern" with the need to shape, and the lower part has a fine pipeline directly mold. Attract the upper surface of the mold. After contacting a seed crystal, the melt can automatically expand to the edge of the "pattern" when the surface of the seed crystals is higher than the surface of the seed crystal. Crystals. Its main advantage is that we can grow a variety of shapes according to our requirements. Saint-Gon uses this technology to grow sapphire optical chip with a diameter of 450mm to 500mm. The C -side chip used in the bottom has a patent of this technology. The principle is as shown in Figure 4. This method grows the equipment and process technology of the crystal is more difficult and it is not easy to promote.
FIG. 4 Follower model Crystal growth schematic diagram
FIG. 5 Figure 5 The melter thermal exchange method 350mm sapphire crystal
3. The essence is to control the temperature, so that the melt directly solidifies and crystals in the pupa. Its main technical feature is that there must be a temperature gradient furnace. This temperature gradient furnace is a thermal exchanger made of tungsten molybdenum on the bottom of the vacuum hunger resistance furnace, which has cooling the air flow. Put the ingredients equipped with raw materials at the top of the thermal exchanger, and the center of the two coincides with each other, and the seed crystals are placed at the center of the bottom of the cricket. After the raw materials in the cricket are heated and melted, the gas flowing through the heat switch cooled. Make the seed crystal not melted. Subsequently, increased the flow of pyrethians, took away more melt heat, gradually grew the seed crystal, and finally solidified the whole melt in the entire pupae. The main advantages of this method are: During the growth of crystals, 坩埚, crystals, and heating areas do not move, eliminating the shortcomings of the crystal due to mechanical movement; at the same time, it can control the cooling rate, reduce the thermal stress of the crystal, and the crystal generated by this. Cracking and wrong defects are a good way to grow high -quality large crystals. However, the equipment conditions of this method are high, the entire process is complicated, and the operating cost is high, so it is not widely used. This process is a patented technology for Crystal System, mainly providing a rectifier for the U.S. military. At present, it has grown 350mm sapphire crystal (Figure 5).
4. The melting bubble method
The melting bubble method was invented by Kyropouls in 1926. After decades of continuous improvement and improvement of scientific researchers. One of the ways to pull diameter crystals. The principle of its growth crystal is shown in Figure 6. The main technical characteristics are: placing the crystal raw materials to be growing in a high -temperature resistance, heating and melting, and then adjusting the temperature field in the furnace, so that the upper part of the melt is slightly higher than the melting point state than the melting point state ; Put a seed crystal on the seed crystal rod to let the seed crystal contact the melting melting surface. After the surface of the seed crystal is melted, reduce the surface temperature to the melting point, pull and rotate the seed crystal rod, so that the top of the melt is in a cold state and the top of the melt is too cold. Crystal on the seed crystal, in the process of continuous lifting, grows cylindrical crystals. The crystal does not contact the cricket during the growth process or at the end of the growth, which greatly reduces the stress of the crystal and can obtain a high -quality large diameter crystal. It is different from the melting crystal raising method that the crystal diameter is relatively large when expanding the shoulder, almost the same diameter as the diameter (comparison Figure 1 and Figure 6). Process characteristics and difficulties. Zhejiang Juhua Group Corporation Crystal Material Factory has developed this high -quality sapphire growth technology by combining the melting bubble method and the melting lifting technology, and uses the growth of colorless high -quality sapphire crystals as the main product. Some people also also This method is called "melt bubble Tirafa". At present, high -quality colorless sapphire crystals with a diameter of more than 220mm or more and weighing 28kg or more. The product is shown in Figure 6.
FIG. 6 The principle of the melt bubble growth crystal and its products
. The process of the melting bubble growth method of high -quality sapphire crystal
1) The pure α -Al2O3 will be The raw materials are loaded into the cricket.旋 There is a rotary and lifting tie rod on the top. There is a seed crystal fixture at the lower end of the pole, which is equipped with a oriented colorless sapphire seed crystal (Note: When the colorless sapphire does not cause the color, the seed crystal must also be used for colorless sapphire, colorless sapphire crystal ratio than non -colored sapphire ratio Crystals are more useful).
2) Heat the above 2050 ° C, reduce the lifting rod, and insert the seed crystal into the melt.
3) Control the temperature of the melt, so that the temperature of the liquid surface is slightly higher than the melting point. A small amount of seed crystals are melted to ensure that it can start to grow on the surface of the seed crystal.
4) After the implementation of the seed crystal and the melt is fully moisturized, the temperature of the liquid surface is at the melting point, and the seed crystal rod is slowly lifted up and rotated. Control the speed and speed, and the seed crystal gradually grows up.
5) Carefully adjust the heating power so that the temperature of the liquid surface is equal to the melting point, and the entire growth process of the growth of the neck of the gemstone -expanded shoulder -equivalent -the end.
The growth device is placed in an outer cover so that the inert gas is charged in the vacuum, so that the gas and pressure in the growth environment can be maintained in the growth environment. The crystal growth can be observed through the window on the outer cover so that the temperature can be adjusted at any time, so that the crystal growth process is carried out normally. This method can grow large colorless sapphire crystals with high diameter and high -quality diameter.
. The technical point of the fuse bubble growth method to grow high -quality sapphire
sered sapphire belongs to the three -party crystal system. There are two main sliding systems in the crystal structure (the bottom of the bottom surface and the column surface sliding system) Therefore, in the use of the sapphire single crystal process, the reasonable choice of the temperature gradient of the temperature field and the direction of crystal growth will have a key impact on the quality of the sapphire single crystal.
1. Establishing a reasonable temperature gradient is the primary condition for growth high -quality crystals
The thermal system is the determined factor of temperature gradient, and it is the basic condition for growing high -quality crystals. When the crystal constant temperature grows, according to the stable conditions of the interface:
The Chinese artificial gem
and n Chinese artificial gems
So there are
The Chinese artificial gem
So the interface is maintained The maximum growth rate of stable is
This Chinese artificial gems
:
and
are the temperature gradients in the melt and crystals near the interface; The thermal conductivity of the crystal; L is crystalline inspiring; ρ is crystal density.
can be seen from the formula (3) that the maximum growth rate of the crystal depends on the temperature of the temperature gradient in the crystal. To increase the growth rate of the crystal, the temperature gradient must be increased. However, too large the temperature ladder in the crystal will increase the thermal stress of the crystal, increase the density of the position, and even cause the crystal to crack.
Therefore, according to the nature of colorless sapphire single crystal, establishing a reasonable temperature gradient is the prerequisite for growing complete single crystals.
2. Selection of the growth direction of the crystal is very important
The colorless sapphire belongs to the three -party crystal system, and there are two main sliding systems: (0001) the bottom surface of the surface of the

The pillar surface sliding system in the direction of the direction of the surface. Sliding is the most likely to occur along the trend with a large atomic density. Therefore, when the crystal growth interface is large with (0001), it is easy to generate a large number of crystal boundaries because the bottom surface is slippery. Formed twins; on the contrary, it is not easy to develop, and the crystal world is not easy to generate.
During the 0 ° orientation (0001), although the symmetrical section of the crystal shape is easy to present hexagonal, the defect will be prioritized in the direction of the optical axis, which is easy to form a inlaid structure and destroy the integrity of the crystal structure.
In this shows that it is necessary to choose the appropriate crystal growth direction. We found the crystal growth direction of high -quality colorless sapphire according to multiple tests. We believe that according to the temperature gradients established, choosing the appropriate crystal growth direction is the key to growing high -quality colorless sapphire single crystals.
5. The application of the melting bubble method grows high -quality colorless sapphire
Gugemal sapphire growing in melt bubbles is usually used in the field of defense industry, military technology and cutting -edge science and technology research. Qualified raw materials can be used in the jewelry industry. The reason why the high -quality sapphire grown in melt bubbles is widely used in the field of defense industry, military technology, and cutting -edge science and technology research. It is determined by the excellent performance of colorless sapphire crystal itself. See Table 1 for partial performance parameters of colorless sapphire single crystals.
Table 1 Performance of colorless sapphire single crystal
1. The application of high -quality colorless sapphire crystals in the base
The high -quality colorless sapphire crystal has become the first choice in some base applications due to its excellent performance. Material. Mainly manifested in the following areas:
1) Blu -ray LED light -emitting diode base material (BLED's) -Coloning on colorless sapphire bases Ⅲ -V and Ⅱ — ⅱ ⅵ ethnic compounds;
2) Infrared detection Instrument -colorless sapphire crystal can be used as the base of the grown cadmium mercury crystal (HGCDTE);
3) The base of the arsenic chip (GaaS);
4) Microwave integrated circuit material.
On the one hand, in the application of microelectronics integrated circuit, R surface —
The colorless sapphire substrate of crystal surface is the preferred material for heterogeneous extension silicon: because colorless sapphire single crystals have high and stable media The frequency of electricity makes it particularly suitable for the heterogeneity of microwave and high -speed integrated circuits and pressure sensing. On the other hand, on the colorless sapphire single crystal, it can be used as a hybrid superconducting compound, making high resistance devices, and can also be used to grow GaaS or use it for other materials.
It -A -side —
The color of colorless sapphire single crystal substrate: Because the colorless sapphire single crystal has a stable dielectric constant and high insulatability, it can be used as a carrier of high -temperature superconducting materials.
It again, C side, 0001 0001｝｝｝｝ single -sided substrate has single or double -sided polishing, which is widely used in extension growth Ⅲ -V and Ⅱ -ⅵ ethnic compounds, such as Blu -ray The GAN substrate used for LED (white light LED is based on the Blu -ray LED, which is produced by the fluorescent powder effect). Secondly, it is also used to make the carriers of mercury cadmium caddy compounds for infrared detection.
2. The application of high -quality colorless sapphire in the field of light -emitting diode (LED)
LED applications is very wide, including communication, consumer electronics, automobiles, lighting, signal lights, etc. We can generally distinguish them as five major areas: backlight, lighting, electronic equipment, display, and cars. Today, the increasingly exhausted earth resources, environmental protection and energy conservation are the focus of the development of various industries today. Especially for the lighting industry that consumes a lot of electricity, in the development of light sources, it is more environmental protection and energy saving. The emergence of light -emitting diode (LED) is a revolution on the world of human lighting, and has a significant impact and change on the future of human beings. In addition to low energy consumption and long life, LED also has the following advantages:
1) Application is very flexible: it can be made into light, thin, short, short products with various shapes, and faces;
2) Environmental protection Good benefits: Because there are no ultraviolet and infrared rays in the spectrum, no heat and radiation, it belongs to a typical green lighting source, and waste can be recycled without pollution;
3) Control is extremely convenient: as long as the current is adjusted, you can adjust at will at will Light, different combinations of light colors are multi -end, using timing control circuits can achieve colorful dynamic changes.
LED can be used not only for large advertising display, but also for construction and traffic lighting. The appearance of white light LED is a substantial step for LED to cross from the identification function to the lighting function. The white light LED is most recently light, which can better reflect the real color of the exposure of the object. Therefore, from a technical point of view, the white light LED is undoubtedly the most cutting -edge technology of LED.
The market application of white light LED will be very wide, and it is also the "killer" of incandescent tungsten light bulbs and fluorescent lamps. At present, white LEDs have begun to enter some actual application areas, such as emergency lights, flashlights, flash and other products.
If according to the US Department of Energy, about 55%of the incandescent lamps and fluorescence lamps in the United States will be replaced by white light Around 2010, and the value of electricity can reach US $ 35 billion per year, which can form a large industry of $ 50 billion. Japan proposed that the white light LED will replace traditional incandescent lamps around 2008. In order to seize the commanding heights of the future market, the three major lighting industry giants such as GM, Philips, and Oslam have acted to form a LED lighting company in cooperation with semiconductor companies. The price is reduced by 99%, how tempting the prospect!
3. The application of high -quality colorless sapphire in the GAN out lining material
high -quality colorless sapphire crystal is currently the only commercial GAN lining material, and the new achievement of semiconductor lighting technology is high -quality colorless colorless colorless colorless colorless colorless colorless colorless colorless non -colorless colorless non -colorless colorless non -colorless colorless non -colorless colorless non -colorless non -colorless non -colorless non -colorless colorless colorless color The application of sapphire crystals has created a new prospect. By extending GAN on colorless sapphire crystal substrates, Blu -ray diode (LED) can be made.
The important use and prospects of LEDs are gradually being recognized by people. With the rapid development of LED industrialization, large -sized and high -quality sapphire crystals will become the new favorite of the market.
. The conclusion
This techniques we combined with the fusion of melt bubbles and melting biram grows high -quality large -diameter colorless sapphire. In order to obtain high -quality colorless sapphire single crystals, in the process of crystal growth, from the characteristics of the crystal itself, a rational selection of growth process with the fusion of temperature gradient and crystal growth direction was established. The application field of high -quality colorless sapphire single crystals growing in melt bubbles is very extensive. It can be applied in the field of national defense industry, military technology, and cutting -edge science and technology research, especially in the field of substrate and light -emitting diode (LED) , Show excellent development prospects.
The references
He Xuemei, Shen Caiqing compiled. 2005. Gem artificial synthesis technology. Beijing: Chemical Industry Press.
Mattalum victory, etc. Observation. Journal of inorganic materials, 13 (1).
Wang Chonglu.1983. White Gem Single Crystal. Tianjin: Tianjin Science and Technology Press.
Yu Xudong et al. Study in the growth direction of sapphire crystal. Journal of artificial crystals, 35 (2).
Zhang Kecong et al. .1997. Crystal growth science and technology. Beijing: Science Press.
Zhang Yulong et al. Application. Beijing: Chemical Industry Publishing House.
Zhang Beilie edited. 2006. System Gemology (2). Beijing: Geological Publishing House.
Patent documents. .
LED lighting prominent advantages and extensive uses. Communication information report, 2006-02-10.
pub.no.: US2005/0227117a1, united states, patent. nschmid f.et al.j .Ser.1970.cerma.soc, 53,528
scheel H j, Fukuda T.2003.The of Crys-Tal Growth, Crystal Growth Technolo-GY, PP.3 ～ 14.

1 thought on “discount jewelry displays wholesale The principle and application of melt bubble growth of high -quality sapphire”

Wilma
November 9, 2022 at 3:00 am

real wholesale jewelry Sun Guangnian Yu Xudong Shen Caiqing
The first author of the author: Sun Guangnian, the first and second members of the China Treasure Association Artificial Gem Committee, the third deputy chairman of the third session, the head of the crystal material factory of the Junhua Group of Zhejiang Province.
. Introduction
Puctual science is one of the three pillars (energy, information, materials) of modern civilization and is the material foundation of human civilization. Crystal growth belongs to the scientific category of materials and is the forefront of its development. Industry has proven that the development of some high -tech science and technology is closely related to crystal materials; the development of military industry, such as missiles, drones, submarines, artificial satellites and spacecraft materials. The quality of these materials determines the level of technical level, and only in terms of materials, can we hope that related technology can break through. High -quality colorless sapphire is very widely used because of its special excellent performance. For example, sapphire single crystal has a unique and excellent physical chemical properties, especially in the 0.2 to 5.0 μm bands. In infrared military equipment, satellite and space technology. Due to the characteristics of sapphire crystal electronics insulation and constant dielectric constants, it has become one of the most widely used substrate materials. To this end, countries around the world are trying to do research and production. After years of hard work, the Crystal Material Factory of Juhua Junhua Group Corporation has produced high -quality colorless sapphires with melting bubble method and melt Tirara. It can be used not only for the window materials of the military industry, but also for the energy -saving and environmental protection industry of substrate materials and light -emitting diode (LED), which has unlimited potential and development prospects.
. High -quality sapphire crystal growth technology is brief
sapphire is a type of gemstone. Except for red ruby, other Jade gems are called sapphire. Colorless sapphire is one of the sapphires. The chemical composition is tritenurtide (Al2O3), a three -party crystal system, a polished surface mask bright glass luster to Agin Kong, one axis crystal negative light, the refractive index value is 1.762 ～ 1.770 The dual refractive index is 0.008 ～ 0.010, the hardness of Mobi is 9, and the density is about 4.00g/cm3.
The artificial synthesis method of sapphire mainly includes flame melting method, melting agent and melting method. The melt method includes several methods. However, neither the flame melting method and the melting agent method cannot grow high -quality sapphire large crystals. The reason is that in addition to the slightly small crystals growing gemstone crystals, the crystals also have a large amount of inlaid structure and poor quality. The gemstone growing in the melting method is also very small, and it contains the help of the melting cation, and the quality is not very good. Only the gemstone growing gemstone growing in the melt method has the characteristics of high purity and integrity, and a single crystal can become a high -quality gemstone crystal that is urgently needed by the modern high -tech and national defense industry. The principle of melt -growth gemstone is: Put the raw materials that constitute the gem component in high temperature resistance, heat and melt, and then cool down by cooling the melt under control conditions, thereby making the crystal grow. Due to the different control conditions of cooling, the method of growing high -quality gemstone crystals from the melt is slightly different. At present, the main melt method of high-quality sapphire crystal growth technology in the world has the following four types: ① melt crystal ticker method; ② EFG (Edge-Defined Film-Fed Growth) melt method; ③HEM (Heat Exchange Method) Following thermal exchange method; ④ METHOD melt bubble method. The above four methods of growing gemstone crystals from the melt, the technical characteristics and advantages and disadvantages are briefly introduced below.
1. The melting crystal tiramine
The melting crystal bira (referred to as the melting Tirafa) is the method of using the seed crystal to grow from the melt to the crystal. This method can grow large and unsuccessful high -quality single crystals in the short term. It was first invented by J. Claston (J.) in 1917, so it is also known as the Chicolaski Law. La Fa is one of the most commonly used methods for growth crystals in the melt. Its main technical characteristics are the common foundation of all the use of Tirafa -growth crystals. The brief description is as follows: put the raw materials of the gem component in the pupa and heated it to the melting point of the raw material. The melt; there is a lifting rod that can rotate and lifts above the pupa. The lower end of the pole has a chip with a seed crystal, which reduces the lifting rod, the seed crystal is inserted into the melt, the temperature is adjusted, and the seeds are adjusted to make the seeds make the seeds. Jing neither melted nor grows up, and then slowly lifted and rotated the seed crystal rod slowly. At the same time, slowly reduce heating power, and through the entire process of growth of neck -shoulder -expanded -such as diameter -equivalent, you can obtain the required diameter crystal. The entire growth device is placed in a closed jacket to make the atmosphere and pressure in the growth environment; the windows of the outer cover can be observed through the window of the outer cover. The principle of growth is shown in Figure 1. The main advantage of this method is: ① It can easily observe the growth of the crystal during the growth process; ② the crystal grows on the surface of the melt, and does not contact the 坩埚Parasitic nucleus; ③ can easily use directional seed crystals and "neck shrinking" process. The error of the seed crystal after "shrinking the neck" can be greatly reduced, so that the crystal that can grow after expanding shoulder is reduced, and its position is reduced and the crystals with high integrity are obtained. The main disadvantage of this method is that the crystals are relatively small, and it can reach up to 2 to 3 inches in diameter
1 inch = 25.4mm. , Cannot adapt to the requirements of modern high -tech and defense industry on large -sized crystals. In the growth of large -sized crystals, the other three methods are better than the melt crystal raising method.
The 1970s, due to the needs of laser materials research, my country began to develop artificial pupaed aluminum gigar (YAG) and artificial raviometer (GGG) crystal melt growth technology. Due to the development of the military industry Need to study and apply with cutting -edge science and technology, the gemstone crystal technology of the melting Tirafa has been further developed and improved. Now it has been able to grow smoothly. Colorless sapphire, synthetic ruby, artificial pupae pillar (YAG), artificial pimyotoma (GGG), synthetic stones, etc.
Figure 1 Following the growth schematic diagram of the grid crystal growth
FIG. 2 Figure 2 Mel is sapphire crystal
Figure 3 Laser crystals growing in melt Tirafa
2. The body guidance method
The melt model method is the improved melt crystal lifting method, which can control the shape of the crystal. Its main technical features are: placing an inert mold of a high melting point in the melt, the upper surface of the mold has a "pattern" with the need to shape, and the lower part has a fine pipeline directly mold. Attract the upper surface of the mold. After contacting a seed crystal, the melt can automatically expand to the edge of the "pattern" when the surface of the seed crystals is higher than the surface of the seed crystal. Crystals. Its main advantage is that we can grow a variety of shapes according to our requirements. Saint-Gon uses this technology to grow sapphire optical chip with a diameter of 450mm to 500mm. The C -side chip used in the bottom has a patent of this technology. The principle is as shown in Figure 4. This method grows the equipment and process technology of the crystal is more difficult and it is not easy to promote.
FIG. 4 Follower model Crystal growth schematic diagram
FIG. 5 Figure 5 The melter thermal exchange method 350mm sapphire crystal
3. The essence is to control the temperature, so that the melt directly solidifies and crystals in the pupa. Its main technical feature is that there must be a temperature gradient furnace. This temperature gradient furnace is a thermal exchanger made of tungsten molybdenum on the bottom of the vacuum hunger resistance furnace, which has cooling the air flow. Put the ingredients equipped with raw materials at the top of the thermal exchanger, and the center of the two coincides with each other, and the seed crystals are placed at the center of the bottom of the cricket. After the raw materials in the cricket are heated and melted, the gas flowing through the heat switch cooled. Make the seed crystal not melted. Subsequently, increased the flow of pyrethians, took away more melt heat, gradually grew the seed crystal, and finally solidified the whole melt in the entire pupae. The main advantages of this method are: During the growth of crystals, 坩埚, crystals, and heating areas do not move, eliminating the shortcomings of the crystal due to mechanical movement; at the same time, it can control the cooling rate, reduce the thermal stress of the crystal, and the crystal generated by this. Cracking and wrong defects are a good way to grow high -quality large crystals. However, the equipment conditions of this method are high, the entire process is complicated, and the operating cost is high, so it is not widely used. This process is a patented technology for Crystal System, mainly providing a rectifier for the U.S. military. At present, it has grown 350mm sapphire crystal (Figure 5).
4. The melting bubble method
The melting bubble method was invented by Kyropouls in 1926. After decades of continuous improvement and improvement of scientific researchers. One of the ways to pull diameter crystals. The principle of its growth crystal is shown in Figure 6. The main technical characteristics are: placing the crystal raw materials to be growing in a high -temperature resistance, heating and melting, and then adjusting the temperature field in the furnace, so that the upper part of the melt is slightly higher than the melting point state than the melting point state ; Put a seed crystal on the seed crystal rod to let the seed crystal contact the melting melting surface. After the surface of the seed crystal is melted, reduce the surface temperature to the melting point, pull and rotate the seed crystal rod, so that the top of the melt is in a cold state and the top of the melt is too cold. Crystal on the seed crystal, in the process of continuous lifting, grows cylindrical crystals. The crystal does not contact the cricket during the growth process or at the end of the growth, which greatly reduces the stress of the crystal and can obtain a high -quality large diameter crystal. It is different from the melting crystal raising method that the crystal diameter is relatively large when expanding the shoulder, almost the same diameter as the diameter (comparison Figure 1 and Figure 6). Process characteristics and difficulties. Zhejiang Juhua Group Corporation Crystal Material Factory has developed this high -quality sapphire growth technology by combining the melting bubble method and the melting lifting technology, and uses the growth of colorless high -quality sapphire crystals as the main product. Some people also also This method is called "melt bubble Tirafa". At present, high -quality colorless sapphire crystals with a diameter of more than 220mm or more and weighing 28kg or more. The product is shown in Figure 6.
FIG. 6 The principle of the melt bubble growth crystal and its products
. The process of the melting bubble growth method of high -quality sapphire crystal
1) The pure α -Al2O3 will be The raw materials are loaded into the cricket.旋 There is a rotary and lifting tie rod on the top. There is a seed crystal fixture at the lower end of the pole, which is equipped with a oriented colorless sapphire seed crystal (Note: When the colorless sapphire does not cause the color, the seed crystal must also be used for colorless sapphire, colorless sapphire crystal ratio than non -colored sapphire ratio Crystals are more useful).
2) Heat the above 2050 ° C, reduce the lifting rod, and insert the seed crystal into the melt.
3) Control the temperature of the melt, so that the temperature of the liquid surface is slightly higher than the melting point. A small amount of seed crystals are melted to ensure that it can start to grow on the surface of the seed crystal.
4) After the implementation of the seed crystal and the melt is fully moisturized, the temperature of the liquid surface is at the melting point, and the seed crystal rod is slowly lifted up and rotated. Control the speed and speed, and the seed crystal gradually grows up.
5) Carefully adjust the heating power so that the temperature of the liquid surface is equal to the melting point, and the entire growth process of the growth of the neck of the gemstone -expanded shoulder -equivalent -the end.
The growth device is placed in an outer cover so that the inert gas is charged in the vacuum, so that the gas and pressure in the growth environment can be maintained in the growth environment. The crystal growth can be observed through the window on the outer cover so that the temperature can be adjusted at any time, so that the crystal growth process is carried out normally. This method can grow large colorless sapphire crystals with high diameter and high -quality diameter.
. The technical point of the fuse bubble growth method to grow high -quality sapphire
sered sapphire belongs to the three -party crystal system. There are two main sliding systems in the crystal structure (the bottom of the bottom surface and the column surface sliding system) Therefore, in the use of the sapphire single crystal process, the reasonable choice of the temperature gradient of the temperature field and the direction of crystal growth will have a key impact on the quality of the sapphire single crystal.
1. Establishing a reasonable temperature gradient is the primary condition for growth high -quality crystals
The thermal system is the determined factor of temperature gradient, and it is the basic condition for growing high -quality crystals. When the crystal constant temperature grows, according to the stable conditions of the interface:
The Chinese artificial gem
and n Chinese artificial gems
So there are
The Chinese artificial gem
So the interface is maintained The maximum growth rate of stable is
This Chinese artificial gems
:
and
are the temperature gradients in the melt and crystals near the interface; The thermal conductivity of the crystal; L is crystalline inspiring; ρ is crystal density.
can be seen from the formula (3) that the maximum growth rate of the crystal depends on the temperature of the temperature gradient in the crystal. To increase the growth rate of the crystal, the temperature gradient must be increased. However, too large the temperature ladder in the crystal will increase the thermal stress of the crystal, increase the density of the position, and even cause the crystal to crack.
Therefore, according to the nature of colorless sapphire single crystal, establishing a reasonable temperature gradient is the prerequisite for growing complete single crystals.
2. Selection of the growth direction of the crystal is very important
The colorless sapphire belongs to the three -party crystal system, and there are two main sliding systems: (0001) the bottom surface of the surface of the

The pillar surface sliding system in the direction of the direction of the surface. Sliding is the most likely to occur along the trend with a large atomic density. Therefore, when the crystal growth interface is large with (0001), it is easy to generate a large number of crystal boundaries because the bottom surface is slippery. Formed twins; on the contrary, it is not easy to develop, and the crystal world is not easy to generate.
During the 0 ° orientation (0001), although the symmetrical section of the crystal shape is easy to present hexagonal, the defect will be prioritized in the direction of the optical axis, which is easy to form a inlaid structure and destroy the integrity of the crystal structure.
In this shows that it is necessary to choose the appropriate crystal growth direction. We found the crystal growth direction of high -quality colorless sapphire according to multiple tests. We believe that according to the temperature gradients established, choosing the appropriate crystal growth direction is the key to growing high -quality colorless sapphire single crystals.
5. The application of the melting bubble method grows high -quality colorless sapphire
Gugemal sapphire growing in melt bubbles is usually used in the field of defense industry, military technology and cutting -edge science and technology research. Qualified raw materials can be used in the jewelry industry. The reason why the high -quality sapphire grown in melt bubbles is widely used in the field of defense industry, military technology, and cutting -edge science and technology research. It is determined by the excellent performance of colorless sapphire crystal itself. See Table 1 for partial performance parameters of colorless sapphire single crystals.
Table 1 Performance of colorless sapphire single crystal
1. The application of high -quality colorless sapphire crystals in the base
The high -quality colorless sapphire crystal has become the first choice in some base applications due to its excellent performance. Material. Mainly manifested in the following areas:
1) Blu -ray LED light -emitting diode base material (BLED's) -Coloning on colorless sapphire bases Ⅲ -V and Ⅱ — ⅱ ⅵ ethnic compounds;
2) Infrared detection Instrument -colorless sapphire crystal can be used as the base of the grown cadmium mercury crystal (HGCDTE);
3) The base of the arsenic chip (GaaS);
4) Microwave integrated circuit material.
On the one hand, in the application of microelectronics integrated circuit, R surface —
The colorless sapphire substrate of crystal surface is the preferred material for heterogeneous extension silicon: because colorless sapphire single crystals have high and stable media The frequency of electricity makes it particularly suitable for the heterogeneity of microwave and high -speed integrated circuits and pressure sensing. On the other hand, on the colorless sapphire single crystal, it can be used as a hybrid superconducting compound, making high resistance devices, and can also be used to grow GaaS or use it for other materials.
It -A -side —
The color of colorless sapphire single crystal substrate: Because the colorless sapphire single crystal has a stable dielectric constant and high insulatability, it can be used as a carrier of high -temperature superconducting materials.
It again, C side, 0001 0001｝｝｝｝ single -sided substrate has single or double -sided polishing, which is widely used in extension growth Ⅲ -V and Ⅱ -ⅵ ethnic compounds, such as Blu -ray The GAN substrate used for LED (white light LED is based on the Blu -ray LED, which is produced by the fluorescent powder effect). Secondly, it is also used to make the carriers of mercury cadmium caddy compounds for infrared detection.
2. The application of high -quality colorless sapphire in the field of light -emitting diode (LED)
LED applications is very wide, including communication, consumer electronics, automobiles, lighting, signal lights, etc. We can generally distinguish them as five major areas: backlight, lighting, electronic equipment, display, and cars. Today, the increasingly exhausted earth resources, environmental protection and energy conservation are the focus of the development of various industries today. Especially for the lighting industry that consumes a lot of electricity, in the development of light sources, it is more environmental protection and energy saving. The emergence of light -emitting diode (LED) is a revolution on the world of human lighting, and has a significant impact and change on the future of human beings. In addition to low energy consumption and long life, LED also has the following advantages:
1) Application is very flexible: it can be made into light, thin, short, short products with various shapes, and faces;
2) Environmental protection Good benefits: Because there are no ultraviolet and infrared rays in the spectrum, no heat and radiation, it belongs to a typical green lighting source, and waste can be recycled without pollution;
3) Control is extremely convenient: as long as the current is adjusted, you can adjust at will at will Light, different combinations of light colors are multi -end, using timing control circuits can achieve colorful dynamic changes.
LED can be used not only for large advertising display, but also for construction and traffic lighting. The appearance of white light LED is a substantial step for LED to cross from the identification function to the lighting function. The white light LED is most recently light, which can better reflect the real color of the exposure of the object. Therefore, from a technical point of view, the white light LED is undoubtedly the most cutting -edge technology of LED.
The market application of white light LED will be very wide, and it is also the "killer" of incandescent tungsten light bulbs and fluorescent lamps. At present, white LEDs have begun to enter some actual application areas, such as emergency lights, flashlights, flash and other products.
If according to the US Department of Energy, about 55%of the incandescent lamps and fluorescence lamps in the United States will be replaced by white light Around 2010, and the value of electricity can reach US $ 35 billion per year, which can form a large industry of $ 50 billion. Japan proposed that the white light LED will replace traditional incandescent lamps around 2008. In order to seize the commanding heights of the future market, the three major lighting industry giants such as GM, Philips, and Oslam have acted to form a LED lighting company in cooperation with semiconductor companies. The price is reduced by 99%, how tempting the prospect!
3. The application of high -quality colorless sapphire in the GAN out lining material
high -quality colorless sapphire crystal is currently the only commercial GAN lining material, and the new achievement of semiconductor lighting technology is high -quality colorless colorless colorless colorless colorless colorless colorless colorless colorless non -colorless colorless non -colorless colorless non -colorless colorless non -colorless colorless non -colorless non -colorless non -colorless non -colorless colorless colorless color The application of sapphire crystals has created a new prospect. By extending GAN on colorless sapphire crystal substrates, Blu -ray diode (LED) can be made.
The important use and prospects of LEDs are gradually being recognized by people. With the rapid development of LED industrialization, large -sized and high -quality sapphire crystals will become the new favorite of the market.
. The conclusion
This techniques we combined with the fusion of melt bubbles and melting biram grows high -quality large -diameter colorless sapphire. In order to obtain high -quality colorless sapphire single crystals, in the process of crystal growth, from the characteristics of the crystal itself, a rational selection of growth process with the fusion of temperature gradient and crystal growth direction was established. The application field of high -quality colorless sapphire single crystals growing in melt bubbles is very extensive. It can be applied in the field of national defense industry, military technology, and cutting -edge science and technology research, especially in the field of substrate and light -emitting diode (LED) , Show excellent development prospects.
The references
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Yu Xudong et al. Study in the growth direction of sapphire crystal. Journal of artificial crystals, 35 (2).
Zhang Kecong et al. .1997. Crystal growth science and technology. Beijing: Science Press.
Zhang Yulong et al. Application. Beijing: Chemical Industry Publishing House.
Zhang Beilie edited. 2006. System Gemology (2). Beijing: Geological Publishing House.
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