CN116949563A - Thermal insulation structure and sapphire crystal growth furnace - Google Patents

Abstract

The invention relates to a heat preservation structure and a sapphire crystal growth furnace, wherein the heat preservation structure comprises: the heat insulation layer is used for accommodating the crucible and is provided with a top wall, and a second transverse moving channel for the sapphire lifting shaft to penetrate through and horizontally move is formed in the top wall; and the heat insulation plate is connected to the top wall and can at least partially cover the second transverse moving channel in the process of horizontally moving the sapphire lifting shaft. By arranging the second transverse moving channel, the sapphire lifting shaft can be allowed to horizontally move so as to adjust the distance of the sapphire lifting shaft deviating from the axis of the crucible, so that the seed crystal is eccentrically seeded at a proper position so as to grow crystals with different specifications. The insulation board can cover the second traversing channel at least partially all the time in the process of the horizontal movement of the sapphire lifting shaft, so that the size of a communication port between the insulation layer and the outside can be reduced, and the degree that hot air in the insulation layer escapes through the second traversing channel and air with lower outside temperature enters the insulation layer through the second traversing channel is reduced.

Description

Thermal insulation structure and sapphire crystal growth furnace

Technical Field

The invention relates to the technical field of crystal growth, in particular to a heat insulation structure and a sapphire crystal growth furnace.

Background

Currently, sapphire is increasingly used in the photoelectric industry, and manufacturers generally use a kyropoulos method to produce sapphire, and generally place a seed crystal on an axis position of a crucible for seeding. The existing research shows that the seed crystal is placed at a position deviating from the axis of the crucible for eccentric seeding, so that the growth quality of the crystal is better.

When the eccentric seeding mode is adopted to produce sapphire crystals with different specifications, the distances of the seed crystal deviating from the axis of the crucible are different. For this reason, it is necessary to enable the sapphire pulling shaft of the sapphire crystal growth furnace to be horizontally moved to adjust the distance of the seed crystal from the crucible axis. However, the horizontal movement of the sapphire lifting shaft can cause hot gas in the furnace chamber to be discharged or lower-external-temperature gas to enter the furnace chamber, so that a thermal field in the furnace chamber is destroyed, and the growth quality of sapphire crystals is affected.

Disclosure of Invention

Accordingly, it is necessary to provide a thermal insulation structure and a sapphire crystal growth furnace in order to solve the above-mentioned problems.

In order to solve the problems, the invention provides the following technical scheme:

an insulation construction for sapphire crystal growth furnace, sapphire crystal growth furnace includes crucible and sapphire lift axle, the sapphire is carried and is pulled the axle and can be followed the level and predetermine the direction and remove, insulation construction includes: the heat preservation layer is used for accommodating the crucible and is provided with a top wall, and a second transverse moving channel used for the sapphire lifting shaft to penetrate through and horizontally move is formed in the top wall; and the heat insulation plate is connected to the top wall and can at least partially cover the second transverse moving channel in the process of horizontally moving the sapphire lifting shaft.

In the sapphire crystal growth furnace provided by the invention, the second transverse moving channel is arranged, so that the sapphire lifting shaft can be allowed to horizontally move to adjust the distance of the sapphire lifting shaft deviating from the axis of the crucible, and therefore, eccentric seeding is performed at a proper position to grow crystals with different specifications, and the growth quality of the sapphire crystals is improved. The insulation board can always at least partially cover the second transverse moving channel in the process of horizontally moving the sapphire lifting shaft, so that the size of a communication port between the insulation layer and the outside is reduced. Therefore, in the horizontal movement process of the sapphire lifting shaft relative to the crucible, the degree that hot air in the heat preservation layer escapes through the second transverse moving channel and air with lower external temperature enters the heat preservation layer through the second transverse moving channel can be reduced, so that the influence of movement of the sapphire lifting shaft on the thermal field in the heat preservation layer is reduced, and the growth quality of sapphire crystals is ensured.

In one embodiment, the insulation board is provided with an avoidance channel for penetrating the sapphire lifting shaft, the sapphire lifting shaft can be abutted to the wall of the avoidance channel so as to push the insulation board to move in the horizontal movement process of the sapphire lifting shaft, the avoidance channel and the orthographic projection part of the second traversing channel in the horizontal plane are overlapped, and the overlapped part of the avoidance channel and the orthographic projection of the second traversing channel in the horizontal plane can always cover the orthographic projection of the sapphire lifting shaft in the horizontal plane.

In one embodiment, the thermal insulation board is rotatably connected to the top wall, and the sapphire lifting shaft pushes the thermal insulation board to rotate in the process of horizontally moving the sapphire lifting shaft.

In one embodiment, the evacuation channel is curved.

In one embodiment, the avoidance channel is arc-shaped.

In one embodiment, the second traversing channel is in a segment shape, wherein: when the sapphire lifting shaft horizontally moves to the middle point of the second transverse moving channel, the sapphire lifting shaft is positioned at the curved middle point of the avoidance channel; and/or the second traversing channel is provided with a first starting point, the avoiding channel is provided with a second starting point, and when the sapphire lifting shaft moves to the first starting point, the sapphire lifting shaft is positioned at the second starting point of the avoiding channel; and/or the second traversing channel is provided with a first end point, the avoiding channel is provided with a second end point, and when the sapphire lifting shaft moves to the first end point, the sapphire lifting shaft is positioned at the second end point of the avoiding channel.

In one embodiment, one of the top wall and the heat insulation board is provided with a first annular piece, and the other one is provided with a second annular piece, and the first annular piece and the second annular piece are in sliding fit.

In one embodiment, the first ring member is provided with an annular groove, the second ring member is an annular protrusion, and the second ring member is inserted into the annular groove to form the sliding fit.

In one embodiment, the heat-insulating plate is circular, the heat-insulating plate is a revolution body, and the rotation shaft of the heat-insulating plate is coincident with the axis of the heat-insulating plate.

The invention also provides a sapphire crystal growth furnace, which comprises the sapphire lifting shaft and the heat preservation structure.

Drawings

Fig. 1 is a schematic structural view of a sapphire crystal growth furnace according to an embodiment of the present invention;

FIG. 2 is a top view of the sapphire crystal growth furnace of FIG. 1;

FIG. 3 is a top view of another embodiment of a sapphire crystal growth furnace;

fig. 4 is a schematic structural view of a sapphire crystal growth furnace according to yet another embodiment of the present invention;

FIG. 5 is a schematic diagram of the connection of a portion of the structure of the embodiment of FIG. 4, wherein the sapphire lifting shaft, the thermal insulation board and the top wall are simplified;

FIG. 6 is a schematic diagram illustrating a positional relationship between a second traverse motion path and a avoidance path according to the embodiment of FIG. 4, where the first starting point and the second starting point are located at the same horizontal position in the state shown in FIG. 6;

FIG. 7 is a schematic diagram illustrating a positional relationship between a second traverse motion channel and a avoiding channel in the embodiment of FIG. 4, and the state shown in FIG. 7 may be obtained by further rotating the heat insulation board counterclockwise based on the state shown in FIG. 6;

FIG. 8 is a schematic diagram illustrating a positional relationship between a second traverse motion channel and a avoiding channel in the embodiment of FIG. 4, and the state shown in FIG. 8 can be obtained by further rotating the heat insulation board counterclockwise based on the state shown in FIG. 7;

FIG. 9 is a schematic diagram showing a positional relationship between a second traverse channel and an avoidance channel in the embodiment of FIG. 4, where in the state shown in FIG. 9, the midpoint of the second traverse channel and the midpoint of the avoidance channel are located at the same horizontal position, and further rotating the insulation board counterclockwise based on the state shown in FIG. 8 can obtain the state shown in FIG. 9;

FIG. 10 is a schematic diagram illustrating a positional relationship between a second traverse motion channel and a avoiding channel in the embodiment of FIG. 4, and further rotating the thermal insulation board counterclockwise based on the state shown in FIG. 9 may obtain the state shown in FIG. 10;

FIG. 11 is a schematic diagram illustrating a positional relationship between a second traverse motion channel and a avoiding channel in the embodiment of FIG. 4, and the state shown in FIG. 11 may be obtained by further rotating the heat insulation board counterclockwise based on the state shown in FIG. 10;

fig. 12 is a schematic diagram showing a positional relationship between a second traverse motion channel and a avoiding channel in the embodiment of fig. 4, where in the state shown in fig. 12, the first end point and the second end point are located at the same horizontal position, and further rotating the heat insulation board counterclockwise based on the state shown in fig. 11 may obtain the state shown in fig. 12.

Reference numerals: 1. a sapphire lifting shaft; 2. a furnace body; 21. a furnace cover; 211. a first traversing channel; 22. a furnace wall; 221. a second outlet channel; 23. a furnace chamber; 3. melting soup; 4. a thermal insulation structure; 41. a heat preservation layer; 411. a thermal insulation cover; 412. a heat preservation cylinder; 413. a heat preservation cavity; 414. a top wall; 415. a second traversing channel; 416. a first outlet channel; 417. an annular groove; 42. a thermal insulation board; 421. an avoidance channel; 5. a crucible; 6. a heating device; 7. seed crystal; 81. a feeding channel; 82. a feeding pipe; 91. an air intake passage; 92. an air inlet pipe; 10. sapphire crystal.

Detailed Description

In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the invention, whereby the invention is not limited to the specific embodiments disclosed below.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

Referring to fig. 1, the present invention provides a sapphire crystal growth furnace, which comprises a furnace body 2, a heat insulation structure 4, a crucible 5 and a sapphire lifting shaft 1. The furnace body 2 comprises a furnace cover 21 and a furnace wall 22, and the furnace cover 21 and the furnace wall 22 are surrounded to form a furnace chamber 23. The insulating structure 4 is located in the furnace chamber 23 and comprises an insulating layer 41 with a top wall 414, the insulating layer 41 is of a hollow structure, an insulating cavity 413 is formed in the insulating layer 41, the crucible 5 is located in the insulating cavity 413, and the crucible 5 has a central axis. Before starting the sapphire crystal growth furnace, powdery alumina raw material can be added into the crucible 5; after the sapphire crystal growth furnace is started, the crucible 5 is heated to melt the alumina raw material into molten soup 3, and then the sapphire crystal 10 starts to grow by extending the seed crystal 7 into the heat preservation cavity 413 through the sapphire lifting shaft 1 to contact with the molten soup 3.

It will be appreciated that in order to facilitate removal of the sapphire crystal 10 after growth is completed, a gap is left between the maximum grown sapphire crystal 10 of the sapphire crystal growth furnace and the side wall of the crucible 5. For convenience of the following description, the following definitions are made: the gap between the sapphire crystal 10 which can be grown out of the sapphire crystal growing furnace at maximum and the side wall of the crucible 5 is an amorphous region, and the space occupied by the sapphire crystal 10 which can be grown out of the sapphire crystal growing furnace at maximum is a crystal growth region. In other words, the amorphous region is located between the growth region and the side wall of the crucible 5 and surrounds the growth region for growing the sapphire crystal 10.

Referring to fig. 1 in combination with fig. 2 and 3, the sapphire crystal growth furnace provided by the present invention further includes a feeding channel 81, where the feeding channel 81 sequentially penetrates through the furnace cover 21 and the heat insulation cover 411. In the process of growing the sapphire crystal 10, the molten soup 3 in the crucible 5 is continuously consumed, the liquid level of the molten soup 3 gradually descends to make a certain space in the crucible 5, at this time, the alumina raw material is thrown into the space through the feeding channel 81, and after entering the crucible 5, the alumina raw material is melted into the molten soup 3 to participate in the growth of the sapphire crystal 10. In other words, the raw materials participating in the growth of the sapphire crystal 10 are added to the crucible 5 through the feeding passage 81 in addition to the alumina raw materials added to the crucible 5 before the start-up of the sapphire crystal growth furnace, and the added alumina raw materials are fed into the crucible 5 through the feeding passage 81 during the growth of the sapphire crystal 10, so that the molten soup 3 formed is increased due to the increase of the alumina raw materials, and the size of the grown sapphire crystal 10 is increased.

It should be noted that the powdered alumina raw material is put into the crucible 5, then covered on the surface of the molten metal 3, and gradually heated and melted to become a part of the molten metal 3. In this process, since the growing sapphire crystal 10 is rotating, the molten soup 3 in the crucible 5 is agitated by the sapphire crystal 10 to rotate, which causes the alumina raw material that has not been melted to move toward the side wall of the crucible 5 away from the sapphire crystal 10, thereby preventing the alumina raw material in the crucible 5 from contacting the surface of the sapphire crystal 10 to affect the growth quality of the sapphire crystal 10.

Referring to fig. 1 in combination with fig. 2 and 3, the sapphire crystal growth furnace includes a feed pipe 82, and the feed pipe 82 is disposed through the feed channel 81. The feeding pipe 82 has a feed inlet and a discharge outlet, and the feed inlet is communicated with a space outside the furnace body 2. Alumina raw material enters the feed pipe 82 from the feed inlet, and then leaves the feed pipe 82 from the discharge outlet and falls down into the crucible 5. Preferably, the tap orifice is located within the crucible 5 near the edge of the opening of the crucible 5.

In some embodiments, a feed valve is provided on the feed tube 82 that opens to allow alumina feedstock to enter the crucible 5 during replenishment of the alumina feedstock into the crucible 5; in other cases, the feed valve is closed to isolate the space inside the furnace 2 from the space outside the furnace 2. The feed tube 82 may be a bellows.

In order to prevent the growing sapphire crystal 10 from blocking the path of the alumina raw material into the crucible 5 and also to prevent the surface of the sapphire crystal 10 from being stained with the alumina raw material to affect the growth quality of the sapphire crystal 10, the axis of the feeding tube 82 is located outside the crystal growth region. In other words, the alumina feedstock enters the crucible 5 through the non-growth zone.

The powdery alumina raw material includes powdery particles having a larger size and powdery particles having a smaller size, wherein the powdery particles having a smaller size form dust during falling toward the crucible 5, and the growth quality of the sapphire crystal 10 is affected if the dust flies to the surface of the growing sapphire crystal 10.

The shorter the distance the alumina raw material falls, the less dust is formed during the fall. In some embodiments, the feeding pipe 82 is disposed through the feeding channel 81 in a lifting manner. Therefore, the height difference between the discharge port of the feeding pipe 82 and the liquid level of the molten steel 3 can be changed by lifting the feeding pipe 82, so that the alumina raw material leaves the feeding pipe 82 at a proper position and falls into the crucible 5 by a short distance, thereby reducing dust. Specifically, in some embodiments, the feeding pipe 82 is clamped to the wall of the feeding channel 81, and the feeding pipe 82 can be lifted by applying an external force to the feeding pipe 82. In other embodiments, the feed tube 82 is slidingly coupled to the wall of the feed channel 81 and the sliding direction is along the height of the sapphire crystal growth furnace. The connection relationship between the feed pipe 82 and the wall of the feed passage 81 is not particularly limited in the present invention.

Referring to fig. 1 in combination with fig. 2 and 3, the sapphire crystal growth furnace further includes an air inlet channel 91, the air inlet channel 91 sequentially penetrates through the furnace cover 21 and the heat insulation cover 411, the air inlet pipe 92 is located above the crucible 5, the air outlet of the air inlet pipe 92 faces the crucible 5, air flow is introduced into the air inlet pipe 92 to form an annular air shield in the crucible 5, and dotted lines in fig. 2 and 3 represent positions of the annular air shield. The distance between the axis of the air inlet channel 91 and the central axis of the crucible 5 is smaller than the distance between the axis of the feeding channel 81 and the central axis of the crucible 5. Thus, the annular wind shield can separate the region through which the growing sapphire crystal 10 and the falling alumina raw material pass (hereinafter simply referred to as "feeding region") so as to prevent flying dust from drifting to the surface of the sapphire crystal 10 to affect the growth quality of the sapphire crystal 10.

Referring to fig. 1 in combination with fig. 2 and 3, the sapphire crystal growth furnace includes an air inlet pipe 92, and the air inlet pipe 92 is disposed through an air inlet channel 91. The air inlet pipe 92 has an air inlet communicating with the space outside the furnace body 2 and an air outlet facing the crucible 5 and communicating with the space inside the crucible 5. A gas (e.g., argon, nitrogen) for forming an annular shield enters the inlet tube 92 from the inlet port and exits the inlet tube 92 from the outlet port and blows toward the crucible 5, thereby forming an annular shield. In some embodiments, the air inlet pipe 92 is liftably disposed through the air inlet passage 91. Thereby, the height difference between the air outlet and the liquid surface of the molten metal 3 can be changed by lifting and lowering the air inlet pipe 92 to form an annular air shield within a proper height range. Specifically, in some embodiments, the air inlet pipe 92 is clamped to the wall of the air inlet channel 91, and the air inlet pipe 92 can be lifted by applying an external force to the air inlet pipe 92. In other embodiments, the air inlet pipe 92 is slidably connected to the wall of the air inlet passage 91 and the sliding direction is along the height direction of the sapphire crystal growth furnace. The connection relationship between the intake pipe 92 and the wall of the intake passage 91 is not particularly limited in the present invention.

Referring to fig. 1 in combination with fig. 2 and 3, in order to form an annular air shield, a plurality of air inlet passages 91 are provided, and a plurality of air inlet passages 91 are provided around the heat insulation board 42. Accordingly, a plurality of air inlet pipes 92 are provided, and a plurality of air inlet pipes 92 are provided around the heat insulation board 42.

Preferably, the air inlet passages 91 are provided in plural, and the plurality of air inlet passages 91 are circumferentially distributed around the central axis of the crucible 5. Correspondingly, the plurality of air inlet pipes 92 are circumferentially distributed with the central axis of the crucible 5 as an axis. Illustratively, the openings of the single inlet passage 91 formed in the lid 21 and top wall 414 may be circular (as shown in FIG. 2) or may be generally arcuate (as shown in FIG. 3).

First, the melting point of the alumina raw material was 2050 ℃, in other words, the temperature of the molten soup 3 was 2050 ℃. The temperature of the position above the liquid surface of the molten soup 3 is about 1700 ℃. In the process of growing the sapphire crystal, the sapphire crystal growth furnace discharges inert protective gas (such as argon and nitrogen) to the outside, and the discharged inert protective gas has a certain waste heat, which is about 500-1000 ℃. The inert shielding gases may be recovered and heated to 1600-1700 c and then introduced into the area above the level of the melt 3 through the inlet pipe 92 to form an annular air shield. Wherein the air inlet pipe 92 may be a quartz tube. Secondly, in the growth process of the sapphire crystal, a certain temperature difference is needed to enable the surface of the sapphire crystal to be continuously solidified, so that the sapphire crystal is continuously grown. The inert protective gases play a certain role in cooling the growth position of the sapphire crystal in the process of being downwards and continuously close to the liquid level of the molten soup 3, and are beneficial to solidifying the surface of the sapphire crystal and growing the sapphire crystal. In addition, since the inert shielding gases are heated to a temperature close to a position above the liquid surface of the molten metal 3, and the inert shielding gases are continuously heated by the molten metal 3 in the process of continuously approaching the molten metal 3, the introduced inert shielding gases do not have a great influence on the thermal field in the heat insulation layer 41.

It will be appreciated that the annular wind shield is formed by the air flow blown out from the air outlet of the air inlet pipe 92, and the closer to the air inlet pipe 92, the stronger the wind force of the annular wind shield. Referring to fig. 1 to 3, the air inlet passage 91 and the charging passage 81 are arranged in this order from the inside to the outside in the radial direction of the crucible 5. Of course, the air inlet pipe 92 and the feed pipe 82 are also arranged in this order from the inside to the outside along the radial direction of the crucible 5. This enables the strongest force of the annular wind shield to be located between the growing sapphire crystal 10 and the feed zone to ensure that the annular wind shield adequately separates the growing sapphire crystal 10 from the falling alumina feedstock.

Referring to fig. 1 and 4, the air flow in the annular air screen is divided into a plurality of flows sequentially flowing out of the crucible 5 and the heat insulation structure 4 after reaching the liquid level of the molten steel 3, and the plurality of flows are divided into two types: a first air flow and a second air flow. The flow direction of the first and second air streams is shown by the black arrows in fig. 1 and 4. The first air flow flows in sequence against the liquid surface of the molten soup 3 and the side wall of the crucible 5, thereby bringing the dust out of the crucible 5. The alumina raw material will, during melting, expel gaseous impurities which can also be carried out of the crucible 5 by the first gas flow. Thereby, dust and gaseous impurities can be prevented from remaining in the crucible 5 for a long time to accidentally break through the annular wind shield to fly toward the growing sapphire crystal 10.

The second air flow flows along the liquid level of the molten soup 3, the surface of the sapphire crystal 10, the surface of the seed crystal 7 and the surface of the sapphire lifting shaft 1 in sequence to form a protective air film on the surface of the sapphire crystal 10, and the protective air film can prevent impurities from drifting to the surface of the sapphire crystal 10 to influence the growth quality of the sapphire crystal 10. Even if some of the dust and gaseous impurities break through the annular air shield and the protective air film to contact the sapphire crystal 10, these dust and gaseous impurities are carried out of the crucible 5 and the insulating structure 4 under the continuous blowing of the second air flow.

Referring to fig. 1, the insulation layer 41 has a first air outlet channel 416, and the first air outlet channel 416 penetrates through the top wall 414. The air inlet channel 91, the feeding channel 81 and the first air outlet channel 416 are arranged in sequence from inside to outside along the radial direction of the crucible 5. Of course, the air inlet pipe 92, the feeding pipe 82, and the first air outlet passage 416 are also arranged in this order from inside to outside along the radial direction of the crucible 5. The first air flow leaves the insulation structure 4 from the first air outlet channel 416, thereby discharging dust and gaseous impurities out of the insulation structure 4.

Referring to fig. 1, the included angle between the first air outlet channel 416 and the horizontal plane is α, where α satisfies: alpha is less than 90 DEG and 0 DEG. In other words, the first outlet channel 416 is disposed obliquely. This advantageously increases the area of the opening formed in the top wall 414 of the first gas outlet passage 416 to facilitate the first gas flow and entrained dust and gaseous impurities exiting the crucible 5 and the insulating structure 4 from the first gas outlet passage 416.

Referring to fig. 1, the furnace wall 22 is provided with a second outlet channel 221, and the second outlet channel 221 is located between the furnace cover 21 and the top wall 414 along the plumb direction. Therefore, the first air flow coming out of the first air outlet channel 416 and dust and gaseous impurities carried by the first air flow can be discharged out of the furnace body 2 through the second air outlet channel 221, and the second air flow can be discharged out of the furnace body 2 through the second air outlet channel 221 after being discharged to the heat insulation structure 4 from the gap between the sapphire lifting shaft 1 and the top wall 414. In other words, in the embodiment shown in fig. 1, the first gas flow sequentially flows along the liquid surface of the molten steel 3, the side wall of the crucible 5, the first gas outlet passage 416 and the second gas outlet passage 221, thereby bringing the dust and the gaseous impurities out of the furnace body 2; the second air flow flows along the liquid surface of the molten soup 3, the surface of the sapphire crystal 10, the surface of the seed crystal 7, the surface of the sapphire lift shaft 1, and the second air outlet channel 221 in sequence.

Referring to fig. 1 in combination with fig. 2 and 3, a plurality of feeding passages 81 are provided, and the plurality of feeding passages 81 are circumferentially distributed around the central axis of the crucible 5. Correspondingly, a plurality of feeding pipes 82 are arranged, and the plurality of feeding pipes 82 are circumferentially distributed by taking the central axis of the crucible 5 as an axis. This facilitates the opening of the feed passage 81 and the feed pipe 82 away from the sapphire crystal 10 according to the shape in which the sapphire crystal 10 grows to replenish the alumina raw material into the crucible 5, thereby reducing the possibility of flying dust to the surface of the sapphire crystal 10. Further, the alumina raw material can be simultaneously replenished through a plurality of feeding pipes 82, thereby improving the speed of replenishing the alumina raw material.

Referring to fig. 1, a plurality of first gas outlet passages 416 are provided, and the plurality of first gas outlet passages 416 are circumferentially distributed with the central axis of the crucible 5 as an axis. This facilitates the evacuation of dust and gaseous impurities distributed in different areas out of the insulating structure 4.

Referring to fig. 1, the second gas outlet channels 221 are provided in plurality, and the plurality of second gas outlet channels 221 are circumferentially distributed with the central axis of the crucible 5 as an axis. This facilitates the removal of the first gas stream exiting the first gas outlet passage 416 and entrained dust and gaseous impurities out of the furnace body 2.

In other embodiments, the axes of the circumferential distribution of the plurality of air inlet channels 91, the plurality of air inlet pipes 92, the plurality of feeding channels 81, the plurality of feeding pipes 82, the plurality of first air outlet channels 416, and the plurality of second air outlet channels 221 may be parallel to the central axis of the crucible 5, instead of the central axis of the crucible 5.

Referring to fig. 1, a first channel is formed in the furnace cover 21, and the first channel penetrates the furnace cover 21 along the plumb direction. The sapphire pulling shaft 1 is provided with a first passage so that the seed crystal 7 is positioned in the furnace chamber 23, and thus, the seed crystal 7 positioned in the furnace chamber 23 can be immediately used for seeding after the completion of the material boiling. The top wall 414 is provided with a second channel, and the top wall 414 is penetrated by the second channel along the plumb direction. In the material boiling stage, the sapphire lifting shaft 1 is positioned outside the heat insulation structure 4 and does not pass through the second channel. In the seeding stage, the sapphire pulling shaft 1 is lowered and passes through the second passage, so that the seed crystal 7 is inserted into the heat-preserving chamber 413 to contact the molten soup 3, and the sapphire crystal 10 starts to grow.

Referring to fig. 4, in some embodiments, the first channel also extends in a horizontal direction to form a first traversing channel 211 and the second channel also extends in the same horizontal direction to form a second traversing channel 415. In other words, in the embodiment shown in fig. 2, the first traversing passage 211 is a first passage, the second traversing passage 415 is a second passage, and the second traversing passage 415 and the first traversing passage 211 extend in the same horizontal direction. Thus, the sapphire lift shaft 1 can be lifted and lowered not only through the first traversing passage 211 and the second traversing passage 415, but also horizontally along a horizontal preset direction defined by the first traversing passage 211 and the second traversing passage 415. On the one hand, the sapphire pulling-up shaft 1 can be horizontally moved to a position deviated from the central axis of the crucible 5 to eccentrically seed the carried seed crystal 7, thereby improving the growth quality of the sapphire crystal 10. On the other hand, the sapphire pulling-up shaft 1 can be gradually moved toward the central axis of the crucible 5 during the growth of the sapphire crystal 10, so as to prevent the continuously grown sapphire crystal 10 from contacting the crucible 5 and fully utilizing the space of the crucible 5 to grow the large-sized sapphire crystal 10.

In the embodiment shown in fig. 4, in order to minimize the size of the first and second traverse channels 211 and 415 to improve the thermal insulation performance of the sapphire crystal growth furnace, the first traverse channel 211 has first and second ends in the length direction, which are the left and right ends of the first traverse channel 211, respectively, in fig. 4. The second traversing channel 415 has a third end and a fourth end in the length direction, which are the left and right ends of the second traversing channel 415, respectively, in fig. 4. The first end and the third end are arranged opposite to each other, and the second end and the fourth end are arranged opposite to each other. In order to make the most of the space in the crucible 5 for growing the sapphire crystal 10, the second end and the central axis of the crucible 5 satisfy: when the sapphire pulling shaft 1 is positioned at the second end, the axis of the sapphire pulling shaft 1 is collinear with the central axis of the crucible 5.

Referring to fig. 4 in combination with fig. 5, the insulation structure 4 further includes an insulation board 42, wherein the insulation board 42 is connected to the top wall 414. In the process of horizontally moving the sapphire lifting shaft 1, the heat insulation plate 42 always covers a part of the second traverse channel 415, thereby reducing the size of the communication port between the heat insulation layer 41 and the outside. Therefore, in the horizontal movement process of the sapphire lifting shaft 1 relative to the crucible 5, the degree that hot air in the heat preservation layer 41 escapes through the second transverse moving channel 415 and air with lower external temperature enters the heat preservation layer 41 through the second transverse moving channel 415 can be reduced, so that the influence of the movement of the sapphire lifting shaft 1 on the thermal field in the heat preservation layer 41 is reduced, and the growth quality of the sapphire crystal 10 is ensured.

Referring to fig. 4 in combination with fig. 5, in some embodiments, the heat insulation board 42 is covered on the top wall 414 and provided with a avoidance channel 421, and the avoidance channel 421 is used for penetrating the sapphire lifting shaft 1. In the seeding stage, the sapphire lifting shaft 1 is inserted into the first traversing channel 211, the second traversing channel 415 and the avoiding channel 421. During the horizontal movement of the sapphire lifting shaft 1, the sapphire lifting shaft 1 abuts against the wall of the avoidance channel 421 to push the thermal insulation plate 42 to move.

Referring to fig. 5, the thermal insulation plate 42 is rotatably connected to the top wall 414, and the sapphire lift shaft 1 pushes the thermal insulation plate 42 to rotate while horizontally moving along the first traverse path 211. During the rotation of the thermal insulation board 42, the orthographic projections of the avoiding channel 421 and the second traversing channel 415 in the horizontal plane are only partially overlapped all the time, and the overlapping part covers the orthographic projection of the sapphire lifting shaft 1 in the horizontal plane. In other words, in the process of rotating the heat preservation plate 42, the heat preservation plate 42 always covers a part of the second transverse moving channel 415, so that the size of a communication port between the heat preservation layer 41 and the outside can be reduced, the degree that hot air in the heat preservation layer 41 escapes through the second transverse moving channel 415 and air with lower outside temperature enters the heat preservation layer 41 through the second transverse moving channel 415 is reduced, the influence of the horizontal movement of the sapphire lifting shaft 1 on the thermal field in the heat preservation layer 41 is reduced, and the growth quality of the sapphire crystal 10 is ensured. Moreover, the movement mode of the thermal insulation board 42 is rotation, which can reduce the space occupied by the thermal insulation board 42 in the movement process, save the space in the sapphire crystal growth furnace, and enable the sapphire crystal growth furnace to utilize the saved space to set other structures.

It will be appreciated that in other embodiments, the insulation panels 42 may be rotatably connected to the top wall 414 below the top wall 414.

In the embodiment shown in fig. 4, the thermal insulation board 42 is a cylinder, and the axis of rotation of the thermal insulation board 42 coincides with the axis of itself. In other words, the thermal insulation board 42 rotates about its own axis. Therefore, the space occupied by the heat-insulating plate 42 in the rotation process is unchanged, which is beneficial to reducing the space occupied by the heat-insulating plate 42, so that the space on the surface of the top wall 414 is saved, and the space saved on the surface of the top wall 414 can be used for arranging the structures such as the air inlet pipe 92, the feeding pipe 82 and the like.

Of course, in other embodiments, the thermal insulation board 42 may be other revolution bodies, such as a truncated cone and a disc.

Referring to fig. 5, the avoiding channel 421 is curved, and the second traversing channel 415 is in a line segment shape. Thus, during rotation of the thermal insulation plate 42, only a portion of the second traversing passage 415 communicates with the avoiding passage 421. Specifically, in the embodiment shown in fig. 5, the relief channel 421 has an arc shape. In other embodiments, the avoiding channel 421 may also have an elliptical arc shape or a parabolic shape. The shape of the escape passage 421 is not particularly limited in the present invention. It will be appreciated that in the embodiment of fig. 4 and 5, the diameter of the insulation board 42 is greater than the length of the second traversing channel 415 in order to cover as much of the second traversing channel 415 as the insulation board 42.

The change in the communication position of the second traversing passage 415 and the avoiding passage 421 during the rotation of the thermal insulation board 42 is shown in fig. 6 to 12. In fig. 6 to 11, the thermal insulation board 42 rotates counterclockwise (the direction indicated by the arrow in fig. 6 to 11). To briefly illustrate that only a portion of the second traversing channel 415 is in communication with the avoiding channel 421, the second traversing channel 415 is simplified to a segment in fig. 6 to 12, the avoiding channel 421 is simplified to a segment of an arc, and the dashed circles in fig. 6 to 12 represent circles where trajectories at two ends of the avoiding channel 421 are located. In fig. 6 to 12, the second traversing passage 415 and the avoiding passage 421 have only two intersections or one intersection, in other words, the second traversing passage 415 and the avoiding passage 421 communicate at only two positions or one position during the rotation of the thermal insulation board 42.

Preferably, referring to fig. 9, in the first embodiment, when the sapphire lift shaft 1 (not shown in the figure) horizontally moves to the midpoint of the second traversing channel 415, the sapphire lift shaft 1 is located at the curved midpoint of the avoiding channel 421; referring to fig. 6, the second traversing channel 415 has a first starting point (i.e., the left end of the second traversing channel 415 in fig. 6 to 12), the avoiding channel 421 has a second starting point (i.e., the left end of the avoiding channel 421 in fig. 6 to 12), and the sapphire lift shaft 1 is located at the second starting point of the avoiding channel 421 when the sapphire lift shaft 1 (not shown) moves to the first starting point; referring to fig. 12, the second traversing channel 415 has a first end point (i.e., the right end of the second traversing channel 415 in fig. 6 to 12), the avoiding channel 421 has a second end point (i.e., the right end of the avoiding channel 421 in fig. 6 to 12), and the sapphire lift shaft 1 is positioned at the second end point of the avoiding channel 421 when the sapphire lift shaft 1 (not shown in the drawings) moves to the first end point. Thereby, each position of the escape passage 421 and the second traversing passage 415 can be fully utilized.

In the embodiment shown in fig. 5, the top wall 414 is provided with a first annular member having an annular recess 417. The insulation board 42 is provided with a second annular member (not shown in the drawings) protruding thereon, in other words, the second annular member is an annular protrusion. The second ring member is in sliding engagement with the annular recess 417 to form a rotational connection. In other embodiments, the thermal insulation plate 42 is located above the top wall 414, the first ring member and the second ring member are both annular protrusions, and one of the first ring member and the second ring member is snugly fit over the other to form a sliding fit, such that the thermal insulation plate 42 is rotatably connected to the top wall 414.

The first ring member may be fixedly connected or integral with other portions of the top wall 414 and the second ring member may be fixedly connected or integral with other portions of the insulating panel 42.

It will be appreciated that the positions of the first ring member and the second ring member may be interchanged, namely: the first ring member is provided on the thermal insulation plate 42 and the second ring member is provided on the top wall 414.

In some embodiments, the avoidance channel 421 on the thermal insulation board 42 is adapted to the sapphire lifting shaft 1 in a profiling manner, but the dimension of the avoidance channel 421 is slightly larger than the dimension of the sapphire lifting shaft 1 so as to facilitate lifting and lowering of the sapphire lifting shaft 1.

In some sapphire crystal growth furnaces, which do not require replenishment of alumina feedstock into the crucible 5 during growth of the sapphire crystal 10, the insulating plate 42 may be attached to the top wall 414 and form a sliding connection in a direction that is consistent with the horizontal movement of the sapphire lift shaft 1. The sapphire lifting shaft 1 pushes the insulation board 42 to slide horizontally during the movement. In these embodiments, the thermal insulation board 42 has a size greater than twice the length of the second traverse channel 415 along the horizontal moving direction of the sapphire pulling shaft 1. Therefore, in the horizontal movement process of the sapphire lifting shaft 1, the heat insulation plate 42 can always cover the second transverse moving channel 415, so that the degree that hot air in the heat insulation layer 41 escapes through the second transverse moving channel 415 and air with lower external temperature enters the heat insulation layer 41 through the second transverse moving channel 415 is reduced, the influence of the movement of the sapphire lifting shaft 1 on the thermal field in the heat insulation layer 41 is further reduced, and the growth quality of the sapphire crystal 10 is guaranteed.

In the embodiment shown in fig. 1 and 4, the sapphire crystal growth furnace includes a heating device 6 provided around the crucible 5, and the heating device 6 is operated to heat the crucible 5 to melt the alumina raw material in the crucible 5 into the molten soup 3. The heat preservation 41 includes heat preservation lid 411 and heat preservation section of thick bamboo 412, and heat preservation lid 411 lid is located heat preservation section of thick bamboo 412 and is formed roof 414, and heat preservation lid 411 and heat preservation section of thick bamboo 412 enclose jointly and form heat preservation chamber 413, and crucible 5 and heating device 6 all are located heat preservation chamber 413.

It will be appreciated that in the embodiment shown in fig. 1 and 4, the insulation layer 41 may be considered as a split structure that is spliced up and down. In other embodiments, the insulation layer 41 may be provided as a split structure spliced side-to-side. Illustratively, the insulating layer 41 is divided into a first and a second sub-body by a vertically disposed plane. In other words, the heat insulation layer 41 is formed by splicing the first split and the second split, and a portion of the top wall 414 and a portion of the side wall of the heat insulation layer 41 are located in the first split, and another portion of the top wall 414 and another portion of the side wall of the heat insulation layer 41 are located in the second split. The first and second split bodies can be fixedly connected by threaded connection or clamping connection or riveting so as to assemble the heat insulation layer 41. After the growth of the sapphire crystal 10 is completed, the first and second split bodies are separated to take out the sapphire crystal 10.

The present invention also provides a sapphire crystal growth method for use in the above-described sapphire crystal growth furnace to grow a sapphire crystal 10. The sapphire crystal growth method comprises the following steps:

s100, arranging an annular air shield in the crucible 5;

s200, adding alumina raw materials into the crucible 5 through a feeding channel 81 at a position close to the side wall of the crucible 5;

s300, rotating the sapphire crystal 10 to enable the molten soup 3 to rotate.

The sapphire crystal 10 grown by the sapphire crystal growth method has the following beneficial effects: the supplementary alumina raw material can be put into the crucible 5 in the growth process of the sapphire crystal 10, so that the sapphire crystal 10 with larger size can be grown; the annular wind screen can prevent dust formed by powdery alumina raw materials from drifting to the surface of the growing sapphire crystal 10 to influence the growth quality of the sapphire crystal 10; rotating the molten soup 3 can move the unmelted alumina raw material to the side wall of the crucible 5 away from the sapphire crystal 10, thereby preventing the alumina raw material in the crucible 5 from contacting the surface of the sapphire crystal 10 to affect the growth quality of the sapphire crystal 10.

In some embodiments, the method further comprises the following steps before step S100: s400, moving the sapphire lifting shaft 1 to the first end to conduct eccentric seeding. Thereby, the sapphire-lifting shaft 1 can be moved to the first end deviated from the central axis of the crucible 5 for eccentric seeding, so as to improve the growth quality of the sapphire crystal 10.

In some embodiments, in step S200, alumina feedstock is added to the crucible 5 through the feed channel 81 at a location within the crucible 5 that is horizontally remote from the first end. This can keep the falling alumina raw material as far away from the growing sapphire crystal 10 as possible, and is advantageous in preventing the alumina raw material from drifting to the surface of the growing sapphire crystal 10.

In some embodiments, the sapphire crystal growth method further comprises the steps of: s500. moving the sapphire-lift shaft 1 toward the second end during the growth of the sapphire crystal 10 to prevent the sapphire crystal 10 from contacting the crucible 5. Thereby, it is possible to prevent the continuously grown sapphire crystal 10 from contacting the crucible 5 and to sufficiently utilize the space of the crucible 5 to grow the large-sized sapphire crystal 10.

In some embodiments, in step S100, the annular air shield is caused to form a first air flow and a second air flow within the heat insulation structure 4, the first air flow flowing sequentially against the liquid surface of the molten soup 3 and the side wall of the crucible 5 to carry the dust and gaseous impurities out of the crucible 5, thereby avoiding the dust and gaseous impurities from being left in the crucible 5 for a long time and accidentally breaking through the annular air shield to fly toward the growing sapphire crystal 10. The second air flow flows along the liquid level of the molten soup 3, the surface of the sapphire crystal 10, the surface of the seed crystal 7 and the surface of the sapphire lifting shaft 1 in sequence to form a protective air film on the surface of the sapphire crystal 10, and the protective air film can prevent impurities from drifting to the surface of the sapphire crystal 10 to influence the growth quality of the sapphire crystal 10. Even if some of the dust and gaseous impurities break through the annular air shield and the protective air film to contact the sapphire crystal 10, these dust and gaseous impurities are carried out of the crucible 5 and the insulating structure 4 under the continuous blowing of the second air flow.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims (10)

1. An insulation construction for sapphire crystal growth furnace, sapphire crystal growth furnace includes crucible (5) and sapphire lift axle (1), sapphire lift axle (1) can be along the level presets the direction and remove, its characterized in that, insulation construction includes:

the heat insulation layer (41) is used for accommodating the crucible (5) and is provided with a top wall (414), and the top wall (414) is provided with a second transverse moving channel (415) used for the sapphire lifting shaft (1) to penetrate through and horizontally move; a kind of electronic device with high-pressure air-conditioning system

And the heat insulation plate (42) is connected to the top wall (414), and the heat insulation plate (42) can at least partially cover the second transverse moving channel (415) in the process of horizontally moving the sapphire lifting shaft (1).

2. The heat preservation structure according to claim 1, characterized in that an avoidance channel (421) for penetrating through the sapphire lifting shaft (1) is formed in the heat preservation plate (42), in the process of horizontally moving the sapphire lifting shaft (1), the sapphire lifting shaft (1) can be abutted against the wall of the avoidance channel (421) to push the heat preservation plate (42) to move, the avoidance channel (421) and the orthographic projection part of the second traversing channel (415) in the horizontal plane are overlapped, and the overlapped part of the orthographic projection of the avoidance channel (421) and the second traversing channel (415) in the horizontal plane can always cover the orthographic projection of the sapphire lifting shaft (1) in the horizontal plane.

3. The thermal insulation structure according to claim 2, wherein the thermal insulation board (42) is rotatably connected to the top wall (414), and the sapphire lift shaft (1) pushes the thermal insulation board (42) to rotate during horizontal movement of the sapphire lift shaft (1).

4. A thermal insulation structure according to claim 3, characterized in that the relief channel (421) is curved.

5. The insulation structure according to claim 4, wherein the relief channel (421) is arc-shaped.

6. The insulation structure of claim 5, wherein the second traversing channel (415) is in the form of a line segment, wherein: when the sapphire lifting shaft (1) horizontally moves to the middle point of the second transverse moving channel (415), the sapphire lifting shaft (1) is positioned at the curved middle point of the avoidance channel (421); and/or the number of the groups of groups,

the second traversing channel (415) is provided with a first starting point, the avoiding channel (421) is provided with a second starting point, and when the sapphire lifting shaft (1) moves to the first starting point, the sapphire lifting shaft (1) is positioned at the second starting point of the avoiding channel (421); and/or the number of the groups of groups,

the second traversing channel (415) is provided with a first end point, the avoidance channel (421) is provided with a second end point, and when the sapphire lifting shaft (1) moves to the first end point, the sapphire lifting shaft (1) is positioned at the second end point of the avoidance channel (421).

7. A thermal insulation structure according to claim 3, wherein one of the top wall (414) and the thermal insulation panel (42) is provided with a first annular member and the other is provided with a second annular member, the first and second annular members being a sliding fit.

8. The insulation structure according to claim 7, wherein the first ring member is provided with an annular groove (417), the second ring member is an annular protrusion, and the second ring member is inserted into the annular groove (417) to form the sliding fit.

9. A thermal insulation structure according to claim 3, wherein the thermal insulation board (42) is a revolution body, and the rotation axis of the thermal insulation board (42) coincides with the axis of the thermal insulation board (42).

10. A sapphire crystal growth furnace comprising a sapphire pulling shaft (1) and an insulating structure according to any of claims 1 to 9.