Growth furnace for large-size sapphire plate
By designing a growth furnace for large-size sapphire plates containing feeding components, the problem of difficulty in growing large-size optically uniform sapphire crystals in the prior art is solved, and the continuous and stable growth of sapphire crystals and high-quality results are achieved.
Patent Information
- Application Number
- CN202421152430.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-24
- Publication Date
- 2025-03-25
- Estimated Expiration
- 2034-05-24
AI Technical Summary
It is difficult to grow larger size optically uniform sapphire crystals, especially when the capillary feed channel is interrupted, it is difficult to meet the demand for growing larger size sapphire crystals.
A large-size sapphire plate growth furnace was designed to achieve the continuous growth of sapphire crystals by adding feeding components. The growth furnace includes a furnace body, a crucible assembly, a lifting assembly and a feeding assembly. The temperature is independently controlled by the thermal insulation layer, and the feeding and lifting speed are controlled to maintain the stability of the solid and liquid surfaces, ensuring the sustained and stable growth of the crystal.
The growth of large size and optically uniform sapphire crystals is achieved, avoiding the limitation of increasing the volume of the crucible or excessive raw materials being put into one go, and ensuring the optical uniformity and quality of the product.
Smart Images
Figure CN222666096U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to sapphire growth technology, and in particular to a growth furnace for large-size sapphire plates. Background Art
[0002] Sapphire is a single crystal of aluminum oxide with excellent physical, chemical and optical properties. It is precisely because of the unique optical and physical properties of sapphire that it is often used as a substrate for LED devices, as well as other industrial, civilian and wearable consumer electronic products such as front lasers, gravitational wave interferometers, transparent armor, infrared window materials, etc. Among them, the edge-defined filmfed growth method (EFG method) is a commonly used sapphire crystal growth method. The edge-defined filmfed growth method is a growth method that uses a mold to transport the solution to the top of the mold through capillary action to grow into a crystal. The aluminum oxide raw material in the crucible is heated by a heater to melt into a melt, and the mold is placed at the bottom of the crucible so that the molten liquid aluminum oxide raw material is transported to the top of the mold through the capillary action of the mold and stored in the capillary gap. At this time, the seed crystal is slowly lowered and contacts the upper surface of the mold, so that the seed crystal is slightly melted, and a thin liquid film is formed between the seed crystal and the mold. Then, the seed crystal is pulled at a variable speed to continuously solidify the liquid film to form a single crystal. The shape of the crystal is determined by the shape of the mold. In the process of growing crystals using the guided mold method, a corresponding volume of alumina raw material is generally filled according to the capacity of the crucible, so that the liquid level is as high as possible to ensure that crystals of sufficiently large size can be grown.
[0003] In order to meet the needs of growing large-sized sapphire crystals, there are two commonly used methods. One is to put raw materials into the crucible at one time. The amount of raw materials put in will grow multiple crystals, and the crystal size is greatly limited. The other is to increase the volume of the crucible, such as increasing the diameter of the crucible or increasing the depth of the crucible. By increasing the diameter of the crucible, the volume of the raw materials in the crucible is increased, and by increasing the depth of the crucible, the volume of the raw materials in the crucible is increased, so that the melt needs to climb a greater distance. When the raw material level is too shallow, the melt climbing height is not enough, and the capillary feed channel is easily interrupted, which makes it difficult to grow larger-sized sapphire crystals. Both of the above methods are difficult to grow large-sized optically uniform sapphire crystals. Utility Model Content
[0004] In order to overcome the above-mentioned defects, the present application provides a growth furnace for large-sized sapphire plates, which can achieve the growth of large-sized sapphire crystals by adding a feeding component, and the obtained large-sized sapphire crystals are optically uniform and of good quality.
[0005] The technical solution adopted by this application to solve its technical problems is:
[0006] A growth furnace for large-size sapphire plates, comprising a furnace body, a crucible assembly, a pulling assembly and a feeding assembly, wherein a heat insulating layer is provided in the furnace body, the heat insulating layer divides the furnace body into an upper heating zone and a lower heating zone, the crucible assembly is located in the lower heating zone, the first end of the pulling assembly is located outside the furnace body, the second end of the pulling assembly is located in the crucible assembly, the feeding assembly comprises a feeding container, a funnel, a motor base and a feeding barrel, the feeding container is fixedly mounted on the top of the furnace body, the funnel and the motor base are mounted in the feeding container, a motor is fixedly mounted in the motor base, the motor is used to deliver the raw materials in the funnel to the crucible assembly through the feeding barrel.
[0007] Optionally, an upper insulation layer and an upper heater are provided in the upper heating zone, a lower insulation layer, a lower heater and a bottom insulation layer are provided in the lower heating zone, the upper insulation layer and the lower insulation layer are located on the inner wall of the furnace body, and the bottom insulation layer is located at the bottom of the furnace body.
[0008] Optionally, the heat insulation layer, the upper thermal insulation layer, the lower thermal insulation layer and the bottom thermal insulation layer are all made of graphite hard felt material, and the upper heater and the lower heater are both made of graphite material.
[0009] Optionally, the crucible assembly comprises a crucible, a crucible support plate and a support assembly, the crucible is placed on the crucible support plate, and the crucible support plate is placed in the lower heater through the support assembly.
[0010] Optionally, a crucible cover plate is provided on the crucible, and the support assembly includes a first support rod and a second support rod, the first end of the first support rod is supported on the crucible support plate, the second end of the first support rod extends out of the bottom of the crucible, the first end of the second support rod is supported on the crucible support plate, and the second end of the second support rod is placed on the inner side of the bottom of the crucible.
[0011] Optionally, the crucible, the crucible cover plate and the feeding tube are all made of molybdenum material, the crucible support plate and the first support rod are all made of graphite material, and the second support rod is made of refractory bricks.
[0012] Optionally, the lifting assembly includes a lifting rod and a lifting mechanism connected to the lifting rod, the lifting mechanism is used to drive the lifting rod to move up and down, the first end of the lifting rod is fixedly connected to the first gravity sensor, and the second end of the lifting rod is fixedly connected to the seed crystal.
[0013] Optionally, a feeding port is provided on the feeding container, the funnel is connected to the motor base, and the funnel is connected to the motor base through a discharge port, a screw is provided on the motor, a blanking port is provided on the motor base, the feeding barrel is located directly below the blanking port, and the motor base is placed on a second gravity sensor.
[0014] The beneficial effects of the present application are as follows: in the present application, raw materials are continuously added to the crucible assembly through the feeding assembly to achieve the continuous growth of the sapphire plate, i.e., sapphire crystal, so as to grow larger-sized, optically uniform sapphire crystals. In this growth furnace, the growth of large-sized sapphire crystals can be achieved by adding a feeding assembly, without increasing the volume of the crucible, and without adding too much raw materials to the crucible at one time, so the obtained sapphire crystals are optically uniform and of good quality. In the present application, the furnace body is divided into a relatively independent upper heating zone and a lower heater by an insulating layer, so the upper heating zone and the lower heating zone can be independently temperature-controlled to ensure the temperature stability of the two areas. In the present application, by controlling the feeding speed of the feeding assembly and the pulling speed of the pulling assembly, the solid and liquid levels in the crucible assembly are kept unchanged, and the crystals are kept growing continuously, stably and low, thereby ensuring the quality of the product. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a schematic diagram of the structure of the growth furnace in this application;
[0016] Figure 2 for Figure 1 The enlarged view of point A in the middle;
[0017] In the figure: 100 - furnace body, 101 - insulation layer, 110 - upper heating zone, 111 - upper insulation layer, 112 - upper heater, 120 - lower heating zone, 121 - lower insulation layer, 122 - lower heater, 123 - bottom insulation layer,
[0018] 200-crucible assembly, 210-crucible, 211-crucible cover plate, 212-raw material, 213-mold, 220-crucible support plate, 230-first support rod, 240-second support rod,
[0019] 300-lifting assembly, 310-lifting rod, 320-seed crystal, 330-first gravity sensor,
[0020] 400 - feeding assembly, 410 - feeding container, 411 - feeding port, 420 - funnel, 421 - discharge port, 430 - motor base, 431 - discharge port, 432 - motor, 440 - feeding barrel, 450 - second gravity sensor. DETAILED DESCRIPTION
[0021] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the embodiments described in the present application are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.
[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the following drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the objects used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0023] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.
[0024] Example: Figure 1 and Figure 2As shown, a large-size sapphire plate growth furnace includes a furnace body 100, a crucible assembly 200, a pulling assembly 300 and a feeding assembly 400. The furnace body 100 is provided with a heat insulation layer 101, and the heat insulation layer 101 divides the furnace body 100 into an upper heating zone 110 and a lower heating zone 120. The crucible assembly 200 is located in the lower heating zone 120. The first end of the pulling assembly 300 is located outside the furnace body 100, and the second end of the pulling assembly 300 is located at the crucible. In the assembly 200, the feeding assembly 400 includes a feeding container 410, a funnel 420, a motor base 430 and a feeding tube 440. The feeding container 410 is fixedly installed on the top of the furnace body 100. The funnel 420 and the motor base 430 are installed in the feeding container 410. A motor 432 is fixedly installed in the motor base 430. The motor 432 is used to send the raw material 212 in the funnel 420 to the crucible assembly 200 through the feeding tube 440. Optionally, the furnace body 100 is a rectangular parallelepiped with doors on both sides facing each other.
[0025] like Figure 1 As shown, the heat insulation layer 101 is located in the middle of the furnace body 100, the upper heating zone 110 is located above the heat insulation layer 101, the lower heating zone 120 is located below the heat insulation layer 101, the pulling assembly 300 is arranged in the upper heating zone 110, and the first end, i.e., the upper end, of the pulling assembly 300 is located outside the furnace body 100, and the second end, i.e., the lower end, of the pulling assembly 300 is located in the crucible assembly 200. The crucible assembly 200 is used to place the raw material 212, the pulling assembly 300 lifts the generated sapphire plate, and the feeding assembly 400 is used to add the raw material 212 to the crucible assembly 200.
[0026] In the present application, raw materials are continuously added to the crucible assembly 200 by the feeding assembly 400 to achieve the continuous growth of the sapphire plate, i.e., the sapphire crystal, so as to grow a larger, optically uniform sapphire crystal. In this growth furnace, the growth of large-sized sapphire crystals can be achieved by adding the feeding assembly 400, without increasing the volume of the crucible, and without adding too much raw materials to the crucible at one time, so the obtained sapphire crystals are optically uniform and of good quality. In the present application, the furnace body 100 is divided into a relatively independent upper heating zone 110 and a lower heating zone 120 by the insulation layer 101, so the upper heating zone 110 and the lower heating zone 120 can be independently temperature-controlled to ensure the temperature stability of the two areas. In the present application, by controlling the feeding speed of the feeding assembly 400 and the pulling speed of the pulling assembly 300, the solid and liquid levels in the crucible assembly 200 remain unchanged, and the crystals are kept growing continuously and stably, thereby ensuring the quality of the product.
[0027] like Figure 1As shown, the upper heating zone 110 is provided with an upper insulation layer 111 and an upper heater 112, the lower heating zone 120 is provided with a lower insulation layer 121, a lower heater 122 and a bottom insulation layer 123, the upper insulation layer 111 and the lower insulation layer 121 are located on the inner side wall of the furnace body 100, and the bottom insulation layer 123 is located on the bottom of the furnace body 100. The upper heating zone 110 is heated by the upper heater 112, and the lower heating zone 120 is heated by the lower heater 122. Optionally, two upper heaters 112 are provided in the upper heating zone 110, and the upper insulation layer 111 is used to insulate and keep the upper heater 112 and the inner side wall of the furnace body 100. Four lower heaters 122 are provided in the lower heating zone 120, and the lower heaters 122 are insulated from the inner wall of the furnace body 100 by a lower insulation layer 121, and a bottom insulation layer 123 is provided at the bottom of the inner cavity of the furnace body 100. The upper heating zone 110 and the lower heating zone 120 are separated by the insulation layer 101, so the upper heating zone 110 and the lower heating zone 120 can be independently controlled in temperature, which is convenient for stable temperature control.
[0028] The heat insulating layer 101, the upper heat preservation layer 111, the lower heat preservation layer 121 and the bottom heat preservation layer 123 are all made of graphite hard felt material, and the upper heater 112 and the lower heater 122 are all made of graphite material, thereby improving the heating and heat preservation effects of the furnace body 100.
[0029] like Figure 1 As shown, the crucible assembly 200 includes a crucible 210, a crucible supporting plate 220 and a supporting assembly. The crucible 210 is placed on the crucible supporting plate 220, and the crucible supporting plate 220 is placed in the lower heater 122 through the supporting assembly.
[0030] The crucible 210 is provided with a crucible cover plate 211, and the support assembly includes a first support rod 230 and a second support rod 240. The first end of the first support rod 230 is supported on the crucible support plate 220, and the second end of the first support rod 230 extends out of the bottom of the crucible 210. The first end of the second support rod 240 is supported on the crucible support plate 220, and the second end of the second support rod 240 is placed on the inner side of the bottom of the crucible 210. Optionally, the second end of the second support rod 240 is placed on the bottom insulation layer 123. The first support rod 230 is supported at the center of the crucible 210, and the two second support rods 240 are located on both sides of the first support rod 230. The crucible 210 is used to store raw materials 212, and the crucible 210 is provided with a mold 213 for forming a large-sized sapphire plate. The material of the mold 213 is tungsten, molybdenum, tantalum or iridium.
[0031] The crucible 210 , the crucible cover plate 211 and the feeding tube 440 are all made of molybdenum material, the crucible support plate 220 and the first support rod 230 are all made of graphite material, and the second support rod 240 is made of refractory bricks.
[0032] like Figure 1 As shown, the lifting assembly 300 includes a lifting rod 310 and a lifting mechanism connected to the lifting rod 310, the lifting mechanism is used to drive the lifting rod 310 to move up and down, the first end of the lifting rod 310 is fixedly connected to the first gravity sensor 330, and the second end of the lifting rod 310 is fixedly connected to the seed crystal 320. The seed crystal 320 is used to form a crystal junction and a large-sized crystal, and the first gravity sensor 330 is used to accurately control the lifting speed.
[0033] like Figure 2 As shown, the feeding container 410 is provided with a feeding port 411, the funnel 420 is connected to the motor base 430, and the funnel 420 is connected to the motor base 430 through the discharge port 421, the motor 432 is provided with a screw, the motor base 430 is provided with a drop port 431, the feeding barrel 440 is located directly below the drop port 431, and the motor base 430 is placed on the second gravity sensor 450. When feeding, the raw material enters the funnel 420 through the feeding port 411 of the feeding container 410, and the material in the funnel 420 enters the motor base 430 through the discharge port 421. The motor 432 drives the screw to rotate to deliver the raw material to the drop port 431, and the raw material falls into the feeding barrel 440 through the drop port 431 and enters the crucible 210 to complete the operation of feeding the crucible 210. Figure 1 As shown, the upper end of the feed barrel 440 extends out of the top of the furnace body 100 and is located directly below the motor base 430. The feed barrel 440 passes through the entire upper heating zone 110, and the lower end of the feed barrel 440 extends into the crucible 210. The speed of feeding is controlled by adjusting the rotation speed of the motor 432, and the feeding amount can be accurately controlled by the second gravity sensor 450. In the present application, the feeding assembly 400 is used to feed the crucible 210, the first gravity sensor 330 is used to accurately adjust the pulling speed, and the second gravity sensor 450 is used to accurately adjust the feeding speed, so as to achieve the solid and liquid levels in the crucible 210 remain unchanged, and maintain the continuous and stable growth of the crystal.
[0034] The growth method using the large-size sapphire plate growth furnace comprises the following steps:
[0035] Step 1: First, the raw material 212 is loaded into the crucible 210 and the funnel 420 respectively, and then the furnace body 100 is vacuumed;
[0036] Step 2: Inflate the furnace body 100, and then use the upper heater 112 and the lower heater 122 to heat the furnace body 100, so that the raw materials in the crucible 210 melt;
[0037] Step 3: Perform seeding and shouldering equal diameter stages, adjust the pulling speed through the first gravity sensor 330, adjust the feeding speed through the second gravity sensor 450, and continue until the sapphire crystal is fully grown;
[0038] Step 4: Perform in-situ annealing on the furnace body 100, lower the temperature inside the furnace to the indoor temperature, and then take out the sapphire crystal.
[0039] It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these modifications and improvements are all within the scope of protection of the present application. Therefore, the scope of protection of the patent of the present application shall be subject to the attached claims.
Claims
1. A growth furnace for large-size sapphire plates, characterized in that: The invention comprises a furnace body (100), a crucible assembly (200), a pulling assembly (300) and a feeding assembly (400), wherein a heat insulating layer (101) is provided in the furnace body (100), and the heat insulating layer (101) divides the furnace body (100) into an upper heating zone (110) and a lower heating zone (120), the crucible assembly (200) is located in the lower heating zone (120), a first end of the pulling assembly (300) is located outside the furnace body (100), a second end of the pulling assembly (300) is located in the crucible assembly (200), and the feeding assembly (400) is The material assembly (400) includes a feeding container (410), a funnel (420), a motor base (430) and a feeding tube (440), wherein the feeding container (410) is fixedly installed on the top of the furnace body (100), the funnel (420) and the motor base (430) are installed in the feeding container (410), and a motor (432) is fixedly installed in the motor base (430), and the motor (432) is used to deliver the raw material (212) in the funnel (420) to the crucible assembly (200) through the feeding tube (440).
2. The large-size sapphire plate growth furnace according to claim 1, characterized in that: An upper thermal insulation layer (111) and an upper heater (112) are provided in the upper heating zone (110); a lower thermal insulation layer (121), a lower heater (122) and a bottom thermal insulation layer (123) are provided in the lower heating zone (120); the upper thermal insulation layer (111) and the lower thermal insulation layer (121) are located on the inner side wall of the furnace body (100), and the bottom thermal insulation layer (123) is located at the bottom of the furnace body (100).
3. The large-size sapphire plate growth furnace according to claim 2, characterized in that: The heat insulating layer (101), the upper thermal insulation layer (111), the lower thermal insulation layer (121) and the bottom thermal insulation layer (123) are all made of graphite hard felt material, and the upper heater (112) and the lower heater (122) are both made of graphite material.
4. The large-size sapphire plate growth furnace according to claim 2, characterized in that: The crucible assembly (200) comprises a crucible (210), a crucible support plate (220) and a support assembly. The crucible (210) is placed on the crucible support plate (220), and the crucible support plate (220) is placed in the lower heater (122) through the support assembly.
5. The large-size sapphire plate growth furnace according to claim 4, characterized in that: The crucible (210) is provided with a crucible cover plate (211), and the support assembly comprises a first support rod (230) and a second support rod (240), wherein the first end of the first support rod (230) is supported on the crucible supporting plate (220), and the second end of the first support rod (230) extends out of the bottom of the crucible (210), the first end of the second support rod (240) is supported on the crucible supporting plate (220), and the second end of the second support rod (240) is placed on the inner side of the bottom of the crucible (210).
6. The large-size sapphire plate growth furnace according to claim 5, characterized in that: The crucible (210), the crucible cover plate (211) and the feeding tube (440) are all made of molybdenum material, the crucible support plate (220) and the first support rod (230) are all made of graphite material, and the second support rod (240) is made of refractory bricks.
7. The large-size sapphire plate growth furnace according to claim 1, characterized in that: The lifting assembly (300) includes a lifting rod (310) and a lifting mechanism connected to the lifting rod (310), wherein the lifting mechanism is used to drive the lifting rod (310) to move up and down, wherein the first end of the lifting rod (310) is fixedly connected to a first gravity sensor (330), and the second end of the lifting rod (310) is fixedly connected to a seed crystal (320).
8. The large-size sapphire plate growth furnace according to claim 1, characterized in that: The feeding container (410) is provided with a feeding port (411), the funnel (420) is connected to the motor base (430), and the funnel (420) is connected to the motor base (430) through a discharge port (421), a screw is provided on the motor (432), a discharge port (431) is provided on the motor base (430), the feeding cylinder (440) is located directly below the discharge port (431), and the motor base (430) is placed on a second gravity sensor (450).