CN117418313B - Large-size sapphire crystal growth method based on automatic filling - Google Patents
Large-size sapphire crystal growth method based on automatic filling Download PDFInfo
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- 238000011049 filling Methods 0.000 title claims abstract description 78
- 229910052594 sapphire Inorganic materials 0.000 title claims abstract description 28
- 239000010980 sapphire Substances 0.000 title claims abstract description 28
- 238000002109 crystal growth method Methods 0.000 title claims abstract description 10
- 239000000463 material Substances 0.000 claims abstract description 99
- 239000013078 crystal Substances 0.000 claims abstract description 92
- 238000010438 heat treatment Methods 0.000 claims abstract description 31
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 29
- 239000002994 raw material Substances 0.000 claims abstract description 28
- 238000000034 method Methods 0.000 claims abstract description 26
- 238000012856 packing Methods 0.000 claims abstract description 25
- 238000001816 cooling Methods 0.000 claims abstract description 15
- 230000008569 process Effects 0.000 claims abstract description 14
- 238000005520 cutting process Methods 0.000 claims abstract description 12
- 238000010899 nucleation Methods 0.000 claims abstract description 7
- 238000002844 melting Methods 0.000 claims description 20
- 230000008018 melting Effects 0.000 claims description 20
- 239000007788 liquid Substances 0.000 claims description 16
- 239000000843 powder Substances 0.000 claims description 12
- 230000001681 protective effect Effects 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 5
- 238000005245 sintering Methods 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 5
- 238000003825 pressing Methods 0.000 claims description 4
- 239000002002 slurry Substances 0.000 claims description 4
- 239000012752 auxiliary agent Substances 0.000 claims description 3
- 230000008859 change Effects 0.000 claims description 3
- 239000000155 melt Substances 0.000 claims description 3
- 238000005303 weighing Methods 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims description 2
- 238000005056 compaction Methods 0.000 claims description 2
- 238000000462 isostatic pressing Methods 0.000 claims description 2
- 238000004537 pulping Methods 0.000 claims description 2
- 238000011946 reduction process Methods 0.000 claims description 2
- 238000004513 sizing Methods 0.000 claims description 2
- 238000005429 filling process Methods 0.000 abstract description 8
- 238000002834 transmittance Methods 0.000 abstract description 6
- 239000000758 substrate Substances 0.000 abstract description 5
- 238000005507 spraying Methods 0.000 abstract description 4
- 238000004519 manufacturing process Methods 0.000 abstract description 3
- 238000010309 melting process Methods 0.000 abstract description 3
- 230000003749 cleanliness Effects 0.000 abstract description 2
- 230000000977 initiatory effect Effects 0.000 abstract description 2
- 239000000126 substance Substances 0.000 abstract description 2
- 239000010410 layer Substances 0.000 description 20
- 239000000945 filler Substances 0.000 description 9
- 239000012535 impurity Substances 0.000 description 6
- 230000001788 irregular Effects 0.000 description 6
- 230000007547 defect Effects 0.000 description 5
- 238000000465 moulding Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000000630 rising effect Effects 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 238000004321 preservation Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 238000010792 warming Methods 0.000 description 2
- 230000007123 defense Effects 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/16—Oxides
- C30B29/20—Aluminium oxides
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B11/00—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method
Abstract
The invention belongs to the technical field of sapphire crystals, and particularly relates to a large-size sapphire crystal growth method based on automatic filling. The technological process includes automatic packing, fast heating, seeding, crystal growth, cutting off and cooling, and the packing process is controlled automatically with compact alumina of special size and special packing equipment and the fast heating is completed with two-stage control. The invention can grow large-size sapphire crystals with the diameter of more than 400mm, has low dislocation density and high transmittance, and is suitable for the requirements of LED substrate materials; the filling process is an automatic control process, replaces manual filling, reduces manual investment, saves filling time, and simultaneously ensures cleanliness and safety in the filling process; the rapid heating material melting process shortens the production period and saves the cost; the problem that the hollow stacking initiation chemical material spraying easily occurs in the traditional alumina raw material filling is also solved.
Description
Technical Field
The invention belongs to the technical field of sapphire crystals, and particularly relates to a large-size sapphire crystal growth method based on automatic filling.
Background
Industrial sapphire is an important basic material in modern industry, and has the main component of aluminum oxide, the melting point is as high as 2050 ℃, and the hardness is inferior to that of diamond, so that the industrial sapphire has the characteristics of high temperature resistance, high hardness, good light transmittance and the like, and is widely applied to the fields of LEDs, semiconductors, consumer electronics, instruments, national defense, military industry, aerospace and the like. At present, the filling process of the growth of the sapphire crystal at home is mainly artificial, and the defects of time and labor waste, low safety and the like exist. The method is mainly related to irregular shape and low density of the used high-purity alumina block raw materials, so that the method is limited by the raw materials and is difficult to realize automatic filling. Meanwhile, the problems of irregular raw materials, artificial filling, higher position of the upper surface layer of the filled raw materials relative to a crucible and over-high temperature rising rate are easy to cause the material spraying of the filling hollow stack initiation chemical material.
The invention patent with publication number of CN106987902A adopts a manual operation process of raw material charging, adopts raw materials with two specifications of lump materials and fine materials, has large dependence on people in the raw material pretreatment and filling process, has large possibility of bringing micro impurities by human factors, and takes a long time in the filling process. The invention patent with publication number of CN104109904A is characterized in that the raw material temperature rising and melting process is a one-stage temperature rising mode, the high vacuum temperature rising is realized, the vacuum pump runs for a long time, the stability of the vacuum degree cannot be completely ensured, and the crystal quality is easily affected.
Therefore, it is very necessary to develop a large-size sapphire crystal growth method based on automatic packing, aiming at the problems of the prior art.
Disclosure of Invention
Aiming at the defects of the existing sapphire growth technology, the invention provides a large-size sapphire crystal growth method based on automatic filling.
The invention relates to a large-size sapphire crystal growth method based on automatic packing, which comprises the steps of automatic packing, rapid heating, temperature-regulating seeding, crystal growth, cutting and cooling.
The specific process flow of the large-size sapphire crystal growth method with automatic filling and rapid heating of the invention is as follows in sequence:
1) Automatic filling: according to the size and the filling weight of the crucible, the automatic filling system selects alumina cakes and fine materials with regular shapes, small grooves are formed in the outer ring of the cakes, a layer of fine materials is paved at the bottom of the crucible by an automatic filling machine, then the cakes are stacked in the crucible layer by grabbing or clamping the small grooves, finally alumina fine material powder is filled into the holes and the upper layer, and the automatic filling is completed;
2) Quick heating and melting: the first stage adopts a vacuum heating mode to heat for 4-10h to 300-500 ℃, the second stage adopts an inflatable heating mode, protective atmosphere is filled to heat for 20-40h to the equipment output of 40% -60%, and the material melting temperature reaches 2060-2070 ℃ for a period of time under the output, so that the raw materials are fully melted;
3) And (3) temperature adjustment and seeding: after the raw materials are completely melted, the seed crystal is descended to contact with the liquid level, so that the bearing of the seed crystal is ensured not to drop, and the seed crystal is controlled to be in a non-melted and non-grown state;
4) Crystal growth: the crystal growth is automatically controlled by a program, and the heating power reducing rate is matched according to the weight change per hour calculated by a crystal growth weighing system, so that the shoulder and constant diameter growth of the crystal are controlled;
5) Cutting and cooling: after the crystal grows to reach the cutting weight, the crystal is lifted to separate from residual molten liquid in the crucible, and then the crystal is taken out after cooling.
In the step 1, the alumina cake material can be in a fan shape or a square shape, and is stacked in a crucible through horizontal splicing and vertical lamination;
preferably, the cake materials with the same shape have A, B types, the thickness of A type is 80-120mm, the thickness of B type is 30-60mm, other materials with no difference are matched with A, B types of materials with different thicknesses, and the control of the filling height is facilitated.
In step 1, the size of the alumina cake material is equal to that of the crucibleThe radius is related, if the material is a right-angle fan-shaped cake, the radius is 15-60mm smaller than the radius of the crucible, 4-6 small grooves are uniformly distributed on the outer ring, and the density is 2.75-3.08g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the If the square cake material is square, the side length of the square cake material is 2-20mm smaller than the radius of the crucible which is 0.71 times of the side length of the square cake material, 3-6 small grooves are distributed on the outer ring, and the density of the square cake material is 2.80-3.15g/cm 3 ；
Wherein, the uses of the small groove of the cake material outer ring are as follows: firstly, grabbing, moving and stacking by a gripper during filling of an automatic filling machine; secondly, the small groove is beneficial to heat conduction and gas discharge during material melting, and is convenient for quickly heating the material melting.
In the step 1, the maximum diameter of the fine materials for automatic filling is less than or equal to 3mm, and the filling density is more than or equal to 2.2g/cm 3 。
In the step 1, an automatic filling system automatically matches the filling weight of cake materials and fine materials according to the size of the inner space of a crucible and the filling weight;
in the step 1, according to the matched filling scheme, an automatic filling machine is matched through a series of actions such as grabbing, clamping and the like, a layer of fine materials is paved firstly, the friction coefficient is increased, the cake materials are conveniently and firmly stacked, the cake materials are stacked again, and finally, the rest fine materials are filled into the holes and the upper layer, and the filling is completed.
In step 1, the preparation method of the alumina cake material for automatic filling comprises the following steps:
a. selecting powder and pulping: selecting alumina fine powder with purity more than or equal to 99.9999% and average grain diameter less than or equal to 3 mu m, and mixing the fine powder according to the following mass proportion: pure water: bonding aid= (6-9): (2-3): (0.1-0.5), uniformly mixing the fine powder, the pure water and the bonding auxiliary agent together to prepare slurry;
b. and (5) die filling: adding the weight of the sizing agent into the die, and closing the die;
c. dry pressing: dry-pressing for one time, wherein the pressure is 10-100MPa;
d. isostatic pressing: secondary isostatic compaction, wherein the isostatic pressure is 50-230MPa;
e. high-temperature sintering: sintering the alumina cake forming blank at 1500-1700 deg.c for 5-8 hr.
In the step 2, the first stage adopts vacuum temperature rise, the vacuum degree is less than or equal to 7Pa, the tightness of the crystal growing furnace is ensured to be good, the temperature rise time is 4-10h, the temperature is raised to 300-500 ℃, the temperature in the invention means the temperature close to the liquid level in the crucible, and the vacuum temperature rise can also discharge impurities with low melting point in the furnace;
preferably, the first stage adopts a vacuum heating mode to heat for 4-5h to 380-500 ℃, the second stage adopts an inflatable heating mode, protective atmosphere is inflated to heat for 25-35h to 45% -55% of the equipment output force, and the material melting temperature reaches 2060-2070 ℃ for a period of time under the output force, so that the raw materials are fully melted.
In the step 3, when the raw materials are completely melted to form a melt, the power is reduced, after the temperature is reduced to 2051-2054 ℃, the temperature is stable for 4-8 hours, the seed crystal is reduced to be just contacted with the liquid level, a part of the bottom end of the seed crystal is melted, the surface of the seed crystal is cleaner, the quality of crystal growth is improved, the power is reduced, the seed crystal is reduced, the descending rate is 0.3-1.0mm/min, the contact area of the seed crystal and the liquid level is reduced to be 55-85% of the original lower end surface area of the seed crystal, the bearing is prevented from falling, and the seed crystal is controlled to be in a non-melting and non-growing state when the seed crystal is lowered.
In the step 5, after the crystal growth reaches the cutting weight, the central shaft is quickly lifted, and the lifting speed is 0.3-1.5mm/min, so that the crystal is separated from the residual molten liquid in the crucible;
in the step 5, when the temperature is above 1200 ℃, the cooling rate is 14-21 ℃/h, when the temperature is 1200-800 ℃, the cooling rate is 7-13 ℃/h, when the temperature is below 800 ℃, the cooling rate is 16-24 ℃/h, so that the heat preservation power of the crystal in the furnace body is slowly reduced, the crystal is annealed by using the cooling process, the internal stress accumulated in the crystal in the growing period is eliminated, and the crystal is taken out after being naturally cooled to room temperature.
The beneficial effects of the invention are as follows: (1) Large-size sapphire crystals with the diameter of more than 400mm, particularly 400-750mm, are grown, and the sapphire crystals have low dislocation density and high transmittance and are suitable for the requirements of LED substrate materials; (2) The filling process is an automatic control process, replaces manual filling, reduces manual investment, saves filling time, and simultaneously ensures cleanliness and safety in the filling process; (3) The automatic filling matching quick heating material melting process shortens the production period, saves the cost, uses the large material with regular shape as the cake material, has high density, and can not generate hollow stacks due to tight contact between the material blocks, so even if the heating speed of the raw materials is increased, the raw materials are uniformly heat-absorbing, and the problem that the large lump materials melt down to cause material spraying when the difference of heat-absorbing melting speeds of the material blocks is overlarge due to the fact that the large hollow stacks are easily generated due to the fact that the raw materials are irregular in shape and different in density in the traditional filling mode is solved.
Drawings
FIG. 1 is a diagram of an alumina right angle fan cake for automatic filling;
FIG. 2 is a schematic view of the crucible after automatic filling using right angle fanning dough;
FIG. 3 is a cross-sectional view of the crucible after automatic filling using right angle fanning dough;
FIG. 4 is a diagram of an alumina square cake for automatic packing;
FIG. 5 is a schematic view of the crucible after automatic filling using square cakes;
FIG. 6 is a cross-sectional view of the crucible after automatic filling using square cakes;
FIG. 7 is a flow chart of a crystal growth process for automatic packing and rapid temperature rise.
Detailed Description
The invention will be described in further detail with reference to the following embodiments to better embody the advantages of the invention.
Example 1 is an example of preparing an alumina cake: preparing the material with the radius of 270mm, the thickness of 100mm, the radius of 20mm of the small groove and the density of more than or equal to 3.0g/cm 3 The right-angle fan-shaped cake material for automatic filling mainly comprises the following steps:
a. 16.5kg of high-purity alumina fine powder with the purity of more than or equal to 99.9999% and the average grain diameter of 3 mu m is selected, poured into a mixing tank, 6.2L of pure water is added, 0.7kg of bonding auxiliary agent is added, and the mixture is mixed for more than 40 minutes to prepare slurry;
b. filling the prepared slurry into a special die for the high-purity aluminum oxide right-angle fan-shaped cake material with the automatic filling material with the specification, and completing die assembly;
c. putting into a dry press, and performing primary dry press molding under the pressure of 25 MPa;
d. then placing the mixture into an isostatic press for molding under the pressure of 135 MPa;
e. the obtained alumina fan-shaped cake material molding blank is put into a high-temperature vacuum furnace, the heating speed is 28 ℃/h, the highest temperature is 1620 ℃, the heat preservation is carried out for 5 hours, the radius is 270mm, the thickness is 100mm, 4 small grooves (radius is 20 mm) are reserved, and the density is more than or equal to 3.0g/cm 3 Is used for automatic filling of high-purity alumina right-angle fan-shaped cake products.
The manufacturing processes of cakes with different thicknesses, shapes and densities mainly differ from different molding dies, the consumption of high-purity alumina fine powder is different, and the molding pressure and sintering temperature are different.
Example 2 is a process for automatic packing and rapid warming crystal growth using alumina fanning cake, process flow is shown in fig. 7:
1. automatic filling:
(1) Selecting raw materials:
fan-shaped cake material (see fig. 1) is selected to match with fine material filling material:
and (3) material A: radius 270mm, small groove radius 20mm, 4 small grooves, thickness 100mm, density 3.0g/cm 3 ；
And (2) material B: radius 270mm, small groove radius 20mm, 4 small grooves, thickness 55mm, density 3.0g/cm 3 ；
Fine material: the maximum diameter is less than or equal to 3mm, and the filling density is more than or equal to 2.2g/cm 3 ；
(2) And (3) filling:
a. confirming 404.5kg of crucible filler weight, and simulating and matching the optimal filler matching proportion according to the size of the inner space of the crucible and the filler weight by the system, wherein 16 blocks of A material are required to be 264.3kg, 8 blocks of B material are required to be 72.7kg, and 67.5kg of fine material are required;
b. according to the scheme of matching filling, a machine is matched through a series of actions such as grabbing, clamping and the like, a layer of fine materials are paved firstly, then stacking materials A are filled, 4 blocks are arranged on each layer, 4 layers are formed, materials A are filled up and then stacking materials B are filled up, 2 layers are formed, and finally the rest fine materials are filled into the holes and the upper layers, so that filling is completed, and a schematic diagram and a sectional view of a crucible after automatic filling are shown in fig. 2 and 3;
2. quick heating and melting:
(1) The first stage of vacuum temperature rise, the vacuum degree is less than or equal to 7Pa, the tightness of the crystal growing furnace is guaranteed to be good, the temperature rise time is 4.5h, the temperature is up to 420 ℃, the temperature in the invention refers to the temperature of the crucible close to the liquid level, and impurities with low melting point in the furnace can be discharged through the vacuum temperature rise;
(2) The second stage of inflation and heating: charging protective atmosphere, heating for 25h until the output force of the equipment reaches 45-55%, and keeping for a period of time under the output force, wherein the melting temperature reaches 2060-2070 ℃ to enable the raw materials to be fully melted;
3. and (3) temperature adjustment and seeding: when the raw materials are completely melted to form a melt, reducing power, after the temperature is reduced to 2052 ℃, and the temperature is stable for 4 hours, the seed crystal is lowered to be just contacted with the liquid level, a part of the bottom end of the seed crystal is melted, so that the surface of the seed crystal is cleaner, the quality of crystal growth is improved, the power is reduced, the seed crystal is lowered, the lowering rate is 0.4mm/min, the contact area between the seed crystal and the liquid level is 60% of the original lower end surface area of the seed crystal, the bearing is not dropped, and the seed crystal is controlled to be in a non-melting and non-growing state when the seed crystal is lowered;
4. crystal growth: the crystal growth is automatically controlled by a program, and the proper power reduction rate is matched according to the weight change per hour calculated by a weighing system with the accuracy of 1g, so that the shoulder and constant diameter growth of the crystal are controlled within the expected growth speed control range;
5. cutting and cooling: the cutting weight is reached, the central shaft is quickly lifted, the lifting speed is 0.6mm/min, and the crystal is separated from the residual molten liquid in the crucible; the heat preservation power of the crystal is slowly reduced in the furnace body, the crystal is annealed by utilizing the temperature reduction process, so that the internal stress accumulated in the crystal in the growing period is eliminated, and the crystal is taken out after the crystal is naturally cooled to the room temperature. The cooling rate is 16 ℃/h when the temperature is above 1200 ℃, 9 ℃/h when the temperature is between 1200 and 800 ℃, and 20 ℃/h when the temperature is below 800 ℃.
The diameter of the grown sapphire crystal with 431mm in the embodimentAnd the body is observed by naked eyes, and has no polycrystal and no bubble defect. Detecting dislocation density of 405 pieces/cm by the processed substrate sheet 2 The transmittance of the visible light wave band is higher than 84.1 percent.
Example 3 is a process for automatic packing and rapid warming crystal growth using alumina square cake:
1. automatic filling:
(1) Selecting raw materials:
selecting an alumina square cake material (see figure 4) to match with a fine material filler;
and (3) material A: side length 201.5mm, small groove radius 20mm, small groove 3, thickness 100mm, density 3.05g/cm 3 ；
And (2) material B: side length 201.5mm, small groove radius 20mm, small groove 3, thickness 55mm, density 3.05g/cm 3 ；
Fine material: the maximum diameter is less than or equal to 3mm, and the filling density is more than or equal to 2.2g/cm 3 ；
(2) And (3) filling:
a. confirming the weight of the crucible filler to be 403.2kg, and simulating and matching the optimal filler matching proportion according to the size of the inner space of the crucible and the filler weight by the system, wherein the total amount of the material A is 238.1kg, the total amount of the material B is 26kg, and the total amount of the material B is 139.1kg;
b. according to the scheme of matching filling, a machine is matched through a series of actions such as grabbing, clamping and the like, a layer of fine materials are paved firstly, then stacking materials A are filled, each layer of 4 blocks is filled, 5 layers are added, materials A are filled and then stacking materials B are filled, each layer of 4 blocks is filled, 1 layer is added, and finally the rest fine materials are filled into the holes and the upper layer, so that filling is completed, and a schematic diagram and a sectional view of a crucible after automatic filling are completed are shown in fig. 5 and 6;
2. quick heating and melting: as in example 1;
3. and (3) temperature adjustment and seeding: as in example 1;
4. crystal growth: as in example 1;
5. cutting and cooling: as in example 1.
The sapphire crystal with the diameter of 430mm grown in the embodiment has no polycrystal and no bubble defect by naked eye observation. Detecting dislocation density of 410 pieces/cm by the processed substrate sheet 2 The transmittance of the visible light wave band is higher than 84.2%.
Comparative examples are manual packing and non-rapid temperature rise crystal growth process:
1. and (3) filling:
(1) Selecting raw materials:
the alumina large block with irregular shape has a monolithic weight of about 10-20kg;
the alumina middle lump material with irregular shape has a single block weight of about 5kg to 10kg;
fine material: the maximum diameter is less than or equal to 5mm, and the filling density is more than or equal to 2.2g/cm 3 ；
(2) And (3) filling:
a. the weight of the filler is 406.5kg, and the filler proportion of the raw materials with three specifications of large lump materials, medium lump materials and fine lump materials is as follows: 180kg of large block, 90kg of medium block and 136.5kg of fine material;
b. the manual filling is carried out, a layer of fine materials is paved on the bottom layer, then the large blocks are stacked, the pores of the large blocks are filled with the medium blocks firstly, then the pores are filled with the fine materials, the filling layer is filled, the next filling layer is carried out, and the filling is completed by analogy;
2. heating and melting:
(1) The first stage of vacuum temperature rise, the vacuum degree is less than or equal to 7Pa, the tightness of the crystal growing furnace is guaranteed to be good, the temperature rise time is 5.5h, the temperature is up to 450 ℃, the temperature in the invention refers to the temperature of the crucible close to the liquid level, and impurities with low melting point in the furnace can be discharged through the vacuum temperature rise;
(2) The second stage of inflation and heating: filling protective atmosphere, heating for 55h, and heating to 2068 ℃;
3. and (3) temperature adjustment and seeding: as in example 1;
4. crystal growth: as in example 1;
5. cutting and cooling: as in example 1.
The sapphire crystal with the diameter of 435mm grown in the comparative example has no polycrystal and no bubble defect by naked eye observation. Detecting 422 dislocation density/cm by the processed substrate sheet 2 The transmittance of the visible light wave band is higher than 84 percent.
The comparative example is a traditional filling mode, the raw materials are in irregular shape lump materials and fine materials, the lump materials are different in shape, volume and weight, manual filling is more time-consuming than automatic filling for operators, hollow stacking is easy to occur in the manual filling, and wall hanging and spraying are caused during material melting; in the manual filling process, trace impurities are introduced into the raw materials due to personnel operation, so that the total impurity content of crystals is increased, and the problem can be effectively avoided by an automatic filling method; the traditional filling mode is not suitable for excessively rapid heating, the time consumption is about 60-100h, and the automatic filling matching rapid heating process shortens the heating time to be within 24-50 h.
Claims (8)
1. The large-size sapphire crystal growth method based on automatic filling is characterized by comprising the following process flows:
1) Automatic filling: the automatic filling system selects alumina cakes and fine materials with regular shapes according to the size and the filling weight of the crucible, a small groove is arranged on the outer ring of the cakes, a layer of fine materials is paved at the bottom of the crucible by an automatic filling machine, then the cakes are stacked in the crucible layer by grabbing or clamping the small groove, finally alumina fine material powder is filled into the holes and the upper layer, and the automatic filling is completed; wherein the size of the alumina cake is related to the radius of the crucible, if the size is a right-angle fan-shaped cake, the radius is 15-60mm smaller than the radius of the crucible, 4-6 small grooves are uniformly distributed on the outer ring, and the density is 2.75-3.08g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the If the cake material is square, the side length of the cake material is 2-20mm smaller than the radius of a crucible which is 0.71 times of the side length of the cake material, 3-6 small grooves are distributed on the outer ring, and the density is 2.80-3.15g/cm 3 ；
2) Quick heating and melting: the first stage adopts a vacuum heating mode to heat for 4-10h to 300-500 ℃, the second stage adopts an inflatable heating mode, protective atmosphere is filled to heat for 20-40h to the equipment output of 40% -60%, and the material melting temperature reaches 2060-2070 ℃ for a period of time under the output, so that the raw materials are fully melted;
3) And (3) temperature adjustment and seeding: after the temperature is raised, the raw materials are melted, the seed crystal is lowered to contact with the liquid level, the bearing of the seed crystal is ensured not to drop, and the seed crystal is controlled to be in a non-melted and non-grown state;
4) Crystal growth: the crystal growth is automatically controlled by a program, and the heating power reducing rate is matched according to the weight change per hour calculated by a crystal growth weighing system, so that the shoulder and constant diameter growth of the crystal are controlled;
5) Cutting and cooling: after the crystal grows to reach the cutting weight, the crystal is lifted to separate from residual molten liquid in the crucible, and then the crystal is taken out after cooling.
2. The method for growing large-size sapphire crystals based on automatic packing according to claim 1, wherein the alumina cake material with the same shape has A, B types, the thickness of A type is 80-120mm, the thickness of B type is 30-60mm, other materials have no difference, and A, B materials with different thicknesses are matched, so that the packing height can be controlled conveniently.
3. The method for growing large-size sapphire crystals based on automatic packing according to claim 1, wherein in step 1, the maximum diameter of the fine material for automatic packing is not more than 3mm, and the packing density is not less than 2.2g/cm 3 。
4. An automatic packing-based large-size sapphire crystal growth method according to any of claims 1-3, wherein in step 1, the automatic packing system automatically matches the packing weight of the cake and the fine material according to the size of the inner space of the crucible and the packing weight.
5. A method for growing large-sized sapphire crystals based on automatic packing according to any of claims 1-3, wherein the method for preparing alumina cakes for automatic packing in step 1 comprises the steps of:
a. selecting powder and pulping: selecting alumina fine powder with purity more than or equal to 99.9999% and average grain diameter less than or equal to 3 mu m, and mixing the fine powder according to the following mass proportion: pure water: bonding aid= (6-9): (2-3): (0.1-0.5), uniformly mixing the fine powder, the pure water and the bonding auxiliary agent together to prepare slurry;
b. and (5) die filling: adding the weight of the sizing agent into the mould, and closing the mould;
c. dry pressing: dry-pressing for one time, wherein the pressure is 10-100MPa;
d. isostatic pressing: secondary isostatic compaction, wherein the isostatic pressure is 50-230MPa;
e. high-temperature sintering: sintering the alumina cake forming blank at 1500-1700 deg.c for 5-8 hr.
6. The method for growing large-size sapphire crystals based on automatic packing according to claim 1, wherein in the step 2, the first stage adopts a vacuum heating mode to heat for 4-5h to 380-500 ℃, the second stage adopts a protective atmosphere to heat for 25-35h to 45% -55% of the equipment output force, and the material melting temperature reaches 2060-2070 ℃ for a period of time under the output force, so that the raw materials are fully melted.
7. The method for growing large-size sapphire crystals based on automatic packing according to claim 1, wherein in the step 3, when the raw materials are completely melted to form a melt, the power is reduced, after the temperature is reduced to 2051-2054 ℃ and the temperature is stabilized for 4-8 hours, the seed crystal is reduced to be just contacted with the liquid level, a part of the bottom end of the seed crystal is melted, the surface of the seed crystal is cleaner, so that the quality of crystal growth is improved, the power is reduced, the seed crystal is reduced, the descending speed is 0.3-1.0mm/min, the contact area between the seed crystal and the liquid level is reduced to 55% -85% of the original lower end surface area of the seed crystal, the bearing is not dropped, and the seed crystal is controlled to be in a non-melted and non-grown state after the seed crystal is lowered.
8. The method for growing large-sized sapphire crystals based on automatic packing according to claim 1, wherein in the step 5, the slicing process is as follows: after the crystal grows to reach the cutting weight, the central shaft is quickly lifted, and the lifting speed is 0.3-1.5mm/min, so that the crystal is separated from the residual molten liquid in the crucible; the temperature reduction process is as follows: the cooling rate is 14-21 ℃/h when the temperature is above 1200 ℃, 7-13 ℃/h when the temperature is 1200-800 ℃, and 16-24 ℃/h when the temperature is below 800 ℃.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2009129784A (en) * | 2009-08-03 | 2011-02-10 | Общество с ограниченной ответственностью Научно-производственная фирма "ЭКСИТОН" (RU) | METHOD FOR GROWING SAPPHIRE SINGLE CRYSTAL ON A SHOOTING CRYSTAL REMAINING IN THE MELT IN AUTOMATIC MODE |
| CN102383187A (en) * | 2011-11-28 | 2012-03-21 | 天通控股股份有限公司 | Growth method of sapphire single crystal |
| CN103060913A (en) * | 2013-01-24 | 2013-04-24 | 天通控股股份有限公司 | Growth method of large-scale sapphire crystal |
| CN103710745A (en) * | 2013-12-26 | 2014-04-09 | 南京晶升能源设备有限公司 | Method for automatically controlling growth of 85-120kg sapphire crystals |
| CN104264224A (en) * | 2014-09-19 | 2015-01-07 | 天通控股股份有限公司 | Growth method of large-size square sapphire crystal |
| CN104695010A (en) * | 2014-12-26 | 2015-06-10 | 浙江东海蓝玉光电科技有限公司 | Improved Kyropulos method for quickly preparing large-size sapphire crystals |
| WO2023115910A1 (en) * | 2021-12-21 | 2023-06-29 | 隆基绿能科技股份有限公司 | Feeding method for single crystal furnace, and single crystal furnace and computer-readable storage medium |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2686465A4 (en) * | 2011-03-15 | 2014-08-06 | Gtat Corp | Automated vision system for a crystal growth apparatus |
-
2023
- 2023-12-19 CN CN202311750306.4A patent/CN117418313B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2009129784A (en) * | 2009-08-03 | 2011-02-10 | Общество с ограниченной ответственностью Научно-производственная фирма "ЭКСИТОН" (RU) | METHOD FOR GROWING SAPPHIRE SINGLE CRYSTAL ON A SHOOTING CRYSTAL REMAINING IN THE MELT IN AUTOMATIC MODE |
| CN102383187A (en) * | 2011-11-28 | 2012-03-21 | 天通控股股份有限公司 | Growth method of sapphire single crystal |
| CN103060913A (en) * | 2013-01-24 | 2013-04-24 | 天通控股股份有限公司 | Growth method of large-scale sapphire crystal |
| CN103710745A (en) * | 2013-12-26 | 2014-04-09 | 南京晶升能源设备有限公司 | Method for automatically controlling growth of 85-120kg sapphire crystals |
| CN104264224A (en) * | 2014-09-19 | 2015-01-07 | 天通控股股份有限公司 | Growth method of large-size square sapphire crystal |
| CN104695010A (en) * | 2014-12-26 | 2015-06-10 | 浙江东海蓝玉光电科技有限公司 | Improved Kyropulos method for quickly preparing large-size sapphire crystals |
| WO2023115910A1 (en) * | 2021-12-21 | 2023-06-29 | 隆基绿能科技股份有限公司 | Feeding method for single crystal furnace, and single crystal furnace and computer-readable storage medium |
Non-Patent Citations (2)
| Title |
|---|
| 李海林 ; 武欢 ; 王瑞 ; .自动加料单晶炉的设计与研究.压电与声光.2020,(第02期),全文. * |
| 自动加料单晶炉的设计与研究;李海林;武欢;王瑞;;压电与声光;20200415(第02期);全文 * |
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