Coil lifting device for crystal growing furnace

Abstract

The utility model discloses a coil lifting device for a crystal growing furnace, which relates to the technical field of silicon carbide crystal growing furnaces and comprises a driving transmission component and three lifting transmission components uniformly arranged around a crucible, the driving transmission assembly is in transmission connection with the lifting transmission assembly; the lifting transmission assembly is connected with the heating assembly and used for controlling the height of the heating assembly relative to the crucible. According to the coil lifting device for the crystal growing furnace, the coil is moved through the linkage feeding device, and the three lead screws are integrally fixed, so that the stability of the whole operation of the device is ensured, and the purpose of temperature control can also be realized. The crucible is placed on the tray and is kept in a static state in the technological process, so that the problem of vibration of the crucible can be solved from the source, and poor crystals caused by vibration of the crucible are avoided. The electrodes of the coil are led out from the lead screw, the flanges are welded to the electrodes, the two electrodes play a role in supporting the coil, and the space occupied by the electrodes of the induction coil is saved to a certain extent.

Description

Technical Field

[0001] The utility model relates to the technical field of silicon carbide crystal growth furnaces, in particular to a coil lifting device for a crystal growth furnace. Background Art

[0002] Physical Vapor Transport (PVT) is a common method for growing silicon carbide crystals. In this method, a silicon carbide seed crystal is placed on the lid or top of a graphite crucible. The graphite crucible is filled with silicon carbide powder as a growth raw material. The growth temperature is controlled so that the growth raw material is decomposed into gas phase components and then transported to the seed crystal to crystallize into silicon carbide crystals under the drive of the axial temperature gradient inside the graphite crucible. As the crystal grows and the raw materials are consumed, the axial temperature gradient inside the crucible will change accordingly. These changes will have an important impact on the transportation of gas phase components and their deposition and crystallization on the growth interface. Therefore, the control of the axial temperature gradient inside the graphite crucible is crucial to the growth of crystals.

[0003] The induction heating silicon carbide crystal growth furnace uses electromagnetic induction coils and crystal growth crucibles as heating components. The current mainstream way to control the axial temperature gradient of crystal growth is to adjust the relative position of the heating components during crystal growth. According to the different crystal growth chambers, there are two types: one is that the quartz tube chamber is fixed by lifting the induction coil crucible, and the other is that the metal chamber is fixed by lifting the crystal growth crucible induction coil.

[0004] In recent years, along with the market demand, the demand for silicon carbide has been increasing. Compared with 6 inches, the area of ​​8 inches has increased by about 78%. Due to the reduction of edge loss, the number of chips cut from an 8-inch substrate under the same conditions will increase by nearly 90%. Therefore, the larger the size of the chip, the larger the utilization area. The demand for 8-inch silicon carbide crystal growth equipment is becoming more and more urgent. Quartz tube chamber equipment is not suitable for large-sized silicon carbide crystal growth due to problems such as limited manufacturing size of the quartz tube and low induction efficiency caused by the induction coil and crystal growth crucible due to the existence of the quartz tube.

[0005] At present, the equipment used for growing large-size silicon carbide crystals is mainly metal chamber equipment. Figure 1As shown, the induction coil 012 is fixed at the bottom of the metal furnace body 013 through the coil support frame 011, and the coil electrode is led out from the flange of the side wall of the furnace body 013; the motion module 09 is fixed on the module bracket 010, and the module bracket 010 is fixed at the bottom of the furnace body 013. The motion module 09 is fixed together with the support rod 05 through the connecting bracket 07, and the crucible tray 04 is fixed on the support rod 05; the crucible 03 used for the growth of silicon carbide crystals is wrapped by the insulation material 01 and placed on the crucible tray 04; the welded bellows 06 is used for the vacuum sealing between the support rod 05 and the furnace body 013; the motion module 09 is driven by the motor 08 to drive the support rod 05 to move up and down, so as to realize the lifting and lowering of the crucible 03. The metal chamber equipment grows the crucible 03 by lifting and lowering the crystal, and there is a problem that the vibration generated during the lifting and lowering of the crucible 03 causes the crystal to be defective. Summary of the invention

[0006] In order to solve the above technical problems, the utility model provides a coil lifting device for a crystal growth furnace, which controls the axial temperature gradient of crystal growth by lifting the coil in the metal chamber equipment. The crucible is placed on the tray and remains stationary, avoiding the problem of poor crystal caused by the vibration of the crucible caused by lifting the crucible in the existing solution.

[0007] To achieve the above purpose, the utility model provides the following solutions:

[0008] The utility model provides a coil lifting device for a crystal growth furnace, comprising a driving transmission component and a plurality of lifting transmission components evenly arranged around a crucible; the driving transmission component is in driving connection with at least one of the lifting transmission components; the lifting transmission component is connected with a heating component, and the lifting transmission component is used to control the height of the heating component relative to the crucible.

[0009] Optionally, the lifting transmission assembly includes a screw and a screw nut; the screw nut is rotatably arranged at the bottom of the furnace body, and the screw nut is transmission connected to the drive transmission assembly; the screw nut is sleeved on the outside of the screw and is transmission connected to the screw; the top of the screw is connected to the heating assembly.

[0010] Optionally, the lifting transmission assembly includes three lead screws and three lead screw nuts; the three lead screws are all hollow lead screws, the electrodes of the heating assembly are led out of two of the lead screws to the outside of the furnace body, and a sealing disc is provided on the top of the third lead screw, and the sealing disc is connected to the heating assembly.

[0011] Optionally, the driving transmission assembly includes a motor, a driving wheel and a driven wheel, the driving wheel is arranged on the output shaft of the motor, the driving wheel is drivingly connected to the driven wheel, and the driven wheel is connected to the lifting transmission assembly.

[0012] Optionally, the driving wheel is a driving gear, the driven wheel is a second gear ring, a first slewing bearing and a plurality of second slewing bearings are provided at the bottom of the furnace body, the plurality of second slewing bearings are evenly arranged around the first slewing bearing, the inner ring of the first slewing bearing and the inner ring of the second slewing bearing are respectively connected to the bottom of the furnace body, the outer ring of the first slewing bearing is provided with a first gear ring, the outer ring of the second slewing bearing is provided with a second gear ring, the first gear ring and the second gear ring are meshed with each other, the driving gear is meshed with the first gear ring; the outer ring of the second slewing bearing is coaxially connected to the screw nut.

[0013] Optionally, the driving wheel is a driving pulley, the driven wheel is a driven pulley, the driven wheel is coaxially connected to the lead screw nut, and the driving pulley and the driven pulley are connected via a synchronous belt transmission.

[0014] Optionally, the driving wheel is a driving sprocket, the driven wheel is a driven sprocket, the driven wheel is coaxially connected to the lead screw nut, and the driving sprocket and the driven sprocket are connected via a chain transmission.

[0015] Optionally, the bottoms of the three lead screws are fixedly connected via a lead screw connecting plate.

[0016] Optionally, an insulating component is arranged between the electrode and the lead screw; the insulating component includes an insulating pad and an insulating sleeve; the insulating sleeve is sleeved on the outside of the electrode, the insulating pad is arranged on the top of the lead screw, and the top of the insulating sleeve is connected to the bottom of the insulating pad.

[0017] Optionally, a welded bellows is provided between the top of the lead screw and the inner bottom of the furnace body.

[0018] Compared with the prior art, the utility model has achieved the following technical effects:

[0019] The coil lifting device for the crystal growth furnace in the utility model moves the coil through a linkage feeding device, and the three lead screws are fixed in an integrated manner, which ensures the stability of the overall operation of the device and can also achieve the purpose of temperature control. The crucible is placed on a tray and remains stationary during the process, which can solve the problem of vibration of the crucible from the source and avoid poor crystals caused by the vibration of the crucible. The electrodes of the coil are led out from the lead screw, and flanges are welded on the electrodes. The two electrodes also play the role of supporting the coil, which saves the space occupied by the electrodes of the induction coil to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a structural schematic diagram of a coil lifting device for a crystal growth furnace in the prior art;

[0022] Figure 2 This is a structural principle diagram of the coil lifting device for a crystal growth furnace of the utility model;

[0023] Figure 3 It is a cross-sectional structural schematic diagram of the coil lifting device for a crystal growth furnace of the utility model;

[0024] Figure 4 It is a partial enlarged structural schematic diagram of a sealing disc in a coil lifting device for a crystal growth furnace of the utility model;

[0025] Figure 5 It is a cross-sectional structural schematic diagram of another viewing angle of the coil lifting device for a crystal growth furnace of the utility model;

[0026] Figure 6 It is a partial enlarged structural schematic diagram of the insulating component in the coil lifting device for the crystal growth furnace of the utility model;

[0027] Figure 7 It is a partial enlarged structural diagram of the first slewing bearing and the driving gear in the coil lifting device for the crystal growth furnace of the utility model;

[0028] Figure 8 It is a structural schematic diagram of a second embodiment of the coil lifting device for a crystal growth furnace of the utility model;

[0029] Fig. 9 It is a structural schematic diagram of a third embodiment of the coil lifting device for a crystal growth furnace of the utility model.

[0030] Description of reference numerals: 01, insulation material; 02, seed crystal; 03, crucible; 04, crucible tray; 05, support rod; 06, welding bellows; 07, connecting bracket; 08, motor; 09, motion module; 010, module bracket; 011, coil support frame; 012, induction coil; 013, furnace body;

[0031] 1. Driving wheel; 2. Screw nut; 3. First slewing bearing; 4. Insulation material; 5. Seed crystal; 6. Crucible; 7. Coil bracket; 8. Sealing disc; 9. Welded bellows; 10. Second slewing bearing; 11. Screw; 12. Motor; 13. Motor fixing plate; 14. Support rod; 15. Crucible tray; 16. Induction coil; 17. Furnace body; 19. Screw connecting plate; 20. Insulation sleeve; 21. Insulation pad; 22. Synchronous belt; 23. Chain. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] Embodiment 1:

[0034] like Figures 2 to 7 As shown, this embodiment provides a coil lifting device for a crystal growth furnace, including a driving transmission assembly and three lifting transmission assemblies evenly arranged around the crucible 6; the driving transmission assembly is transmission-connected to at least one lifting transmission assembly; the lifting transmission assembly is connected to the heating assembly, and the lifting transmission assembly is used to control the height of the heating assembly relative to the crucible 6.

[0035] A heat-insulating material 3 is disposed around the crucible 6 , a crucible tray 15 is disposed at the bottom of the heat-insulating material 3 , and the crucible tray 15 is supported and fixed to the inner bottom of the furnace body 17 by a support rod 14 .

[0036] In this specific embodiment, the driving transmission assembly includes a motor 12, a driving wheel 1 and a driven wheel. The driving wheel 1 is arranged on the output shaft of the motor 12, the driving wheel 1 is connected to the driven wheel, and the driven wheel is connected to the lifting transmission assembly. The driving wheel 1 is a driving gear, and the driven wheel is a second gear ring. The bottom of the furnace body 17 is provided with a first slewing bearing 3 and three second slewing bearings 10. The three second slewing bearings 10 are evenly arranged around the first slewing bearing 3. The inner ring of the first slewing bearing 3 and the inner ring of the second slewing bearing 10 are respectively connected to the bottom of the furnace body 17. The outer ring of the first slewing bearing 3 is provided with a first gear ring, and the outer ring of the second slewing bearing 10 is provided with a second gear ring. The first gear ring and the second gear ring are meshed, and the driving gear is meshed with the first gear ring; the outer ring of the second slewing bearing 10 is coaxially connected with the lead screw nut 2.

[0037] The lifting transmission assembly includes three lead screws 11 and three lead screw nuts 2; the lead screw nut 2 is rotatably arranged at the bottom of the furnace body 17, and the lead screw nut 2 is connected to the outer ring of the second slewing bearing 10; the lead screw nut 2 is sleeved on the outside of the lead screw 11 and is transmission-connected to the lead screw 11; the top of the lead screw 11 is connected to the heating assembly. The three lead screws 11 are all hollow lead screws, and the electrodes of the heating assembly are led out of two of the lead screws 11 to the outside of the furnace body 17. A sealing disc 8 is arranged on the top of the third lead screw 11, and the sealing disc 8 is connected to the heating assembly.

[0038] The bottoms of the three lead screws 11 are fixedly connected by a lead screw connecting plate 19, ensuring that the freedom of rotation of a single lead screw 11 around its own axis is constrained, thereby avoiding locking between the lead screw 11 and the lead screw nut 2 when the lead screw nut 2 rotates, and also reducing the possibility of creeping of the lifting transmission assembly, so that the three lead screws 11 can be lifted and lowered synchronously and smoothly.

[0039] An insulating assembly is arranged between the electrode and the lead screw 11; the insulating assembly includes an insulating pad 21 and an insulating sleeve 20; the insulating sleeve 20 is sleeved on the outside of the electrode, the insulating pad 21 is arranged on the top of the lead screw 11 and the bottom of the electrode flange, and the top of the insulating sleeve 20 is connected to the bottom of the insulating pad 21.

[0040] A welded bellows 9 is arranged between the top of the screw 11 and the inner bottom of the furnace body 17. The welded bellows 9 is used to seal the lifting transmission assembly. The bottom of the welded bellows 9 is a slip-on flange, which is sealed to the flange on the furnace body 17 by a sealing ring. The top of the welded bellows 9 is a vacuum flange, two of which are connected and fixed to the insulating gasket 21 and the electrode assembly by insulating bolts, and the third is connected and fixed to the sealing disc 8.

[0041] The heating assembly includes an induction coil 16, the central axis of the induction coil 16 is concentric with the furnace body 17, and is fixed at three points, two of which are fixedly connected by electrodes, and the third is connected and supported by the coil bracket 7. The coil bracket 7 is placed on the sealing disc 8, and the three fixed points are distributed at an angle of 120°; a disc flange is welded between the two electrodes of the induction coil 16, and is sealed between the insulating pad 21.

[0042] Embodiment 2:

[0043] This embodiment is an improved embodiment based on the first embodiment. Figure 8 As shown, in this embodiment, the driving wheel 1 is a driving pulley, the driven wheel is a driven pulley, the driven wheel is coaxially connected to the screw nut 2, and the driving pulley and the driven pulley are connected through a synchronous belt 22.

[0044] Embodiment three:

[0045] This embodiment is an improved embodiment based on the first embodiment. Fig. 9As shown, in this embodiment, the driving wheel 1 is a driving sprocket, the driven wheel is a driven sprocket, the driven wheel is coaxially connected to the screw nut 2, and the driving sprocket and the driven sprocket are connected through a chain 23.

[0046] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, so it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention, and any figure mark in the claims should not be regarded as limiting the claims involved.

[0047] This specification uses specific examples to illustrate the principles and implementation methods of the utility model. The above examples are only used to help understand the method and core idea of ​​the utility model. At the same time, for those skilled in the art, according to the idea of ​​the utility model, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the utility model.

Claims

1. A coil lifting device for a crystal growth furnace, characterized in that: It comprises a driving transmission assembly and a plurality of lifting transmission assemblies evenly arranged around the crucible; the driving transmission assembly is in driving connection with at least one of the lifting transmission assemblies; the lifting transmission assembly is connected with a heating assembly, and the lifting transmission assembly is used to control the height of the heating assembly relative to the crucible.

2. The coil lifting device for a crystal growth furnace according to claim 1, characterized in that: The lifting transmission assembly includes a lead screw and a lead screw nut; the lead screw nut is rotatably arranged at the bottom of the furnace body, and the lead screw nut is transmission-connected to the drive transmission assembly; the lead screw nut is sleeved on the outside of the lead screw and transmission-connected to the lead screw; the top of the lead screw is connected to the heating assembly.

3. The coil lifting device for a crystal growth furnace according to claim 2, characterized in that: The lifting transmission assembly includes three lead screws and three lead screw nuts; the three lead screws are all hollow lead screws, the electrodes of the heating assembly are led out of two of the lead screws to the outside of the furnace body, and a sealing disc is provided on the top of the third lead screw, and the sealing disc is connected to the heating assembly.

4. The coil lifting device for a crystal growth furnace according to claim 2 or 3, characterized in that: The driving transmission assembly comprises a motor, a driving wheel and a driven wheel. The driving wheel is arranged on the output shaft of the motor. The driving wheel is connected to the driven wheel in a transmission manner. The driven wheel is connected to the lifting transmission assembly.

5. The coil lifting device for a crystal growth furnace according to claim 4, characterized in that: The driving wheel is a driving gear, the driven wheel is a second gear ring, a first slewing bearing and a plurality of second slewing bearings are arranged at the bottom of the furnace body, the plurality of second slewing bearings are evenly arranged around the first slewing bearing, the inner ring of the first slewing bearing and the inner ring of the second slewing bearing are respectively connected to the bottom of the furnace body, the outer ring of the first slewing bearing is provided with a first gear ring, the outer ring of the second slewing bearing is provided with a second gear ring, the first gear ring and the second gear ring are meshed, the driving gear is meshed with the first gear ring; the outer ring of the second slewing bearing is coaxially connected to the screw nut.

6. The coil lifting device for a crystal growth furnace according to claim 4, characterized in that: The driving wheel is a driving pulley, the driven wheel is a driven pulley, the driven wheel is coaxially connected to the lead screw nut, and the driving pulley and the driven pulley are connected via a synchronous belt transmission.

7. The coil lifting device for a crystal growth furnace according to claim 4, characterized in that: The driving wheel is a driving sprocket, the driven wheel is a driven sprocket, the driven wheel is coaxially connected to the lead screw nut, and the driving sprocket is connected to the driven sprocket through a chain transmission.

8. The coil lifting device for a crystal growth furnace according to claim 3, characterized in that: The bottoms of the three lead screws are fixedly connected via a lead screw connecting plate.

9. The coil lifting device for a crystal growth furnace according to claim 3, characterized in that: An insulating component is arranged between the electrode and the lead screw; the insulating component includes an insulating pad and an insulating sleeve; the insulating sleeve is sleeved on the outside of the electrode, the insulating pad is arranged on the top of the lead screw, and the top of the insulating sleeve is connected to the bottom of the insulating pad.

10. The coil lifting device for a crystal growth furnace according to claim 2, characterized in that: A welded bellows is arranged between the top of the lead screw and the inner bottom of the furnace body.

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