Silicon particle smelting device and method for producing silicon single crystal rod

Abstract

The invention discloses a silicon particle smelting device and method for single crystal silicon rod production, and relates to the technical field of single crystal silicon production, the silicon particle smelting device comprises a silicon preparation furnace, a smelting device, a smelting piece, a heating piece and a fixing assembly; the number of the smelting devices is more than two, and the smelting devices are uniformly arranged in the silicon preparation cavity; smelting grooves are formed in the surfaces of the smelting pieces; according to the scheme, the four independent smelting devices are adopted, and each smelting tank smelts silicon particles independently, so that the volume of a melt is relatively small, the local temperature gradient is more obvious, and convection and stirring of the melt are promoted. Under the condition, the concentration of impurities in a single smelting tank is relatively low, the impurities are more easily discharged from a melt through diffusion, convection or evaporation, the thermal load and chemical erosion strength of the smelting tank can be reduced, and meanwhile, the overall temperature field is more balanced due to the arrangement position of the smelting device; and the condition of local overheating or supercooling is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of single crystal silicon production, in particular to a silicon particle melting device and method for single crystal silicon rod production BACKGROUND

[0002] Single crystal silicon is a silicon material with a highly ordered crystal structure, whose atomic arrangement presents periodicity and regularity. It is a core material in the fields of semiconductors, photovoltaics, microelectronics, etc. Due to its excellent electrical, optical and mechanical properties, single crystal silicon is widely used in integrated circuits, solar cells, sensors and other high-tech products.

[0003] The preparation of single crystal silicon mainly relies on the Czochralski method (CZ method), which grows a high-purity single crystal silicon ingot from a molten melt by slowly rotating and pulling up a seed crystal.

[0004] Before using the Czochralski method to pull single crystal silicon, multiple key pre-treatment steps need to be completed to ensure the purity of the raw materials and the stability of the process. First, in the preparation stage, high-purity polycrystalline silicon is selected as the raw material, and appropriate dopants (such as phosphorus, boron) are added according to the process requirements to control the conductivity type (P-type or N-type) of the final single crystal silicon. Then, in the melting stage, polycrystalline silicon particles are placed in a high-purity quartz crucible, and the crucible is heated to above 1450°C by an induction heating or resistance heating system to completely melt the polycrystalline silicon into a uniform liquid silicon melt. In this process, temperature equalization and impurity control are required. By precisely adjusting the temperature, the melt temperature is ensured to be neither too high to cause crucible erosion, nor too low to cause incomplete melting, thereby ensuring the stability of the single crystal pulling process. At the same time, in order to reduce oxidation and impurity pollution, inert gas (such as argon) is usually used for environmental protection, and electromagnetic stirring technology can be combined to reduce the accumulation of silicon dioxide (SiO2) and other impurities, further improving the purity of the melt, and providing ideal melting conditions for subsequent single crystal growth.

[0005] In the prior art, the following defects exist in the use of a single crucible for melting: 1. Serious impurity accumulation. Since all silicon particles are melted in the same crucible, impurities are easily enriched in the melt, affecting the purity of the final single crystal silicon.

[0006] 2. Intensified crucible erosion. In the high-temperature melting process, the quartz crucible is long-term heated and eroded by the melt, causing silicon dioxide to dissolve into the silicon melt, which not only shortens the service life of the crucible, but also introduces oxygen impurities, affecting the quality of the single crystal.

[0007] 3. Temperature control is difficult, the volume of the melt in a single crucible is large, and the temperature gradient is large, which leads to uneven local temperature of the melt, thereby affecting the stable growth of the single crystal silicon. SUMMARY

[0008] The present application aims to provide a silicon particle smelting device for single crystal silicon rod production, which solves the problems of impurity accumulation, serious crucible erosion and insufficient temperature control precision in the traditional single-crucible smelting process.

[0009] To solve the above technical problems, the present application adopts the following technical solutions: A silicon particle smelting device for single crystal silicon rod production, comprising: A silicon production furnace is internally provided with a silicon production cavity; the top end of the silicon production cavity is provided with a crystal pulling port, and the two are in communication with each other; The smelting device is two or more in number and is uniformly arranged in the silicon production cavity with the axis of the silicon production furnace as the center; the smelting device comprises: A smelting piece has a smelting groove on the surface for accommodating silicon particles and smelting; A heating piece is installed on the corresponding smelting piece and is used to heat the smelting piece; A fixing assembly is connected to one end of the smelting piece and connected to the inner wall of the silicon production cavity at the other end to support the smelting piece.

[0010] Further technical solutions are that the smelting piece is in a ring-fan structure; the fixing assembly comprises: A first rotating piece is fixed to the inner wall of the silicon production cavity and has a first rotating end; A rotating part is fixedly connected to one end of the first rotating end and is arranged in a direction perpendicular to the axis of the first rotating end; A second rotating piece is arranged parallel to the first rotating piece and has a second rotating end, and the second rotating piece is fixed to the other end of the rotating part; A connecting part is connected to one end of the smelting piece and connected to the second rotating end at the other end, and the connecting part is arranged in a direction perpendicular to the axis of the second rotating end; The first rotating piece drives the rotating part to move, and the second rotating piece drives the connecting part to move, so that the smelting pieces are sequentially spliced to form a spliced ring-shaped smelting structure; It further comprises a communication assembly for communicating the smelting grooves of adjacent smelting pieces to ensure uniform distribution of the melt during smelting.

[0011] Still further technical solutions are that the smelting groove is in a ring-fan structure; the communication assembly comprises: A liquid inlet part comprises: A liquid inlet is provided at one end of the smelting piece, and a liquid inlet groove is provided on the top wall of the liquid inlet; a driving port, located above the liquid inlet and communicated with the liquid inlet tank; an inlet baffle, slidably connected to the liquid inlet groove and capable of blocking the liquid inlet; A driving member is provided in the driving port and is used to drive the inlet baffle to slide in the liquid inlet tank; The liquid outlet portion comprises: A liquid outlet is provided at the other end of the smelting piece, and a liquid outlet groove is provided on the top wall of the liquid outlet; an outlet baffle, slidably connected to the liquid outlet tank, and the sliding direction of the baffle is parallel to the inlet baffle; The starting component is used to control the linkage of the inlet and outlet baffles, including: An extending piece connected to one end of the smelting piece and located above the liquid outlet trough; A lifting piece, one end of which is connected to the inlet baffle and can drive the outlet baffle in the adjacent smelting piece to move; When the smelting parts in the smelting device are spliced ​​in sequence, the insertion part enters the driving port and starts the driving part, causing the inlet baffle to slide into the liquid inlet tank, thereby releasing the blockage of the liquid inlet; When the inlet baffle slides into the liquid inlet trough, the outlet baffle in the adjacent smelting part is driven to slide into the liquid outlet trough through the lifting part to release the blockage of the corresponding liquid outlet and realize the melt communication.

[0012] A further technical solution is that the driving member includes: The driving tooth plate is slidably connected along the driving port and can extend into the liquid inlet tank; a half gear rotatably connected to the driving port and meshing with the driving gear plate; A full gear rotatably connected to the drive port and capable of meshing with the half gear; A sliding rack is slidably connected in the liquid inlet tank and connected to the inlet baffle, and one side of the rack is meshed with the full gear; When the insertion part enters the driving port and pushes the driving gear plate to move, the half gear is driven to rotate, and then the full gear is driven to rotate with a delay, thereby driving the sliding rack to move, and finally driving the inlet baffle to slide into the liquid inlet groove, thereby releasing the blockage of the liquid inlet.

[0013] A further technical solution is that the inner side wall of the silicon making furnace is provided with a plurality of limit grooves along the height direction; the fixing assembly further comprises: a first telescopic member, fixed in the silicon making furnace along a height direction and having a telescopic first telescopic end; A limiting member is slidably connected in the limiting groove, and is connected to the first rotating member on one side and is connected to the first telescopic end on the other side.

[0014] Further, the smelting device is connected in sequence to form a spiral structure under the action of the fixing assembly; the fixing assembly further comprises: A third rotating member is arranged in parallel to one end of the connecting part away from the second rotating member and has a third rotating end which can rotate; The smelting member is fixedly connected to the third rotating end.

[0015] Further, the smelting groove is provided with a pushing assembly; the pushing assembly comprises: A pushing part is arranged to slide along the annular fan-shaped track of the smelting groove; A lifting stopper is arranged between the liquid outlet groove and the pushing part, one end of which is connected to the pushing part, and the other end has a first wedge surface; The side of the outlet baffle close to the pushing part has a second wedge surface corresponding to the first wedge surface; A linkage member is arranged to connect the lifting stopper and another pushing part in adjacent smelting members; The silicon production furnace is provided with: A rotating liquid scraping assembly is arranged in the silicon production furnace along the axis and is used to drive the pushing part at the highest position to slide along the annular fan-shaped track; When the rotating liquid scraping assembly drives the pushing part at the highest position to slide, the lifting stopper is moved synchronously, the first wedge surface acts on the second wedge surface, the outlet baffle is pushed to slide into the liquid outlet groove to unblock the liquid outlet, and the melt in the smelting groove flows to the adjacent smelting groove through the liquid outlet, and finally converges into the smelting groove at the lowest position.

[0016] Further, the pushing part is provided with an extrusion hole which is located above the smelting groove.

[0017] Further, the pushing part is provided with a clamping groove; the rotating liquid scraping assembly comprises: A positioning column is arranged in the silicon production furnace along the axis; A fourth rotating member is arranged on the positioning column and has a fourth rotating end which can rotate; A second telescopic member is arranged on the fourth rotating end and has a second telescopic end which can extend and retract; A liquid scraping member has one end arranged on the second telescopic end and the other end has a clamping part which can be clamped into the clamping groove.

[0018] Further, the linkage member comprises: An upper abutting groove is arranged on the top side of the pushing part; A lower falling groove is arranged on the bottom side of the lifting stopper and can be aligned with the upper abutting groove; The falling block is slidably arranged in the falling groove and can slide into the falling groove along the direction of gravity after the upper abutting groove and the falling groove are aligned, so as to realize linkage connection. The upper abutting member is slidably arranged in the upper abutting groove. The upper pushing member is arranged in the upper abutting groove to control the release or locking of the falling block.

[0019] Further, the upper pushing member comprises: The fifth rotating member is arranged in the upper abutting groove and has a fifth rotating end which can rotate; The rotating part is fixedly connected with the fourth rotating end and rotates along with the fifth rotating end; The first fixed shaft is arranged on the rotating part in a direction parallel to the fifth rotating end, and the first fixed shaft is arranged eccentrically with the rotating part; The second fixed shaft is arranged on the upper abutting member in a direction parallel to the first fixed shaft; The intermediate member is rotatably sleeved on the first fixed shaft at one end and rotatably sleeved on the second fixed shaft at the other end, and is used to drive the upper abutting member to slide when the rotating part rotates, so as to control the release or locking of the falling block.

[0020] Another object of the present application is to provide a method for using a silicon particle smelting device for single crystal silicon rod production, comprising the following steps: S1: raw material preparation, screening the polycrystalline silicon according to a predetermined proportion, removing impurities and oversized or undersized particles to ensure uniform particle size; S2: preheating the smelting device, starting the heating member to raise the temperature of the smelting member to an initial heating temperature, to avoid splashing or oxidation of the polycrystalline silicon caused by sudden heating; S3: silicon particle feeding, under the protection of inert gas, the screened silicon particles are slowly fed into multiple smelting tanks in batches to ensure uniform feeding and avoid local overheating or caking, wherein the inert gas is argon to avoid oxidation reaction of the silicon particles in a high temperature environment; S4: temperature control and smelting, gradually increasing the heating temperature to above the melting point of silicon, and monitoring the temperature of the smelting member in real time through an external temperature control system to avoid silicon evaporation or oxidation caused by overheating; S5: stirring and homogenization, the smelting member is driven to swing by the driving device, so that the molten body forms a dynamic flow, and the molten body in the high temperature zone and the low temperature zone is mixed with each other to reduce the local temperature gradient and improve the quality of the molten body, wherein the swing angle of the smelting member is between 10° and 45° to optimize the temperature uniformity inside the molten body; S6: molten body convergence and crystal pulling, any of the following methods is used for crystal pulling: S6.1: The melt does not converge, and the crystal pulling is performed separately, that is, the melt in each smelting tank is independently subjected to a separate crystal pulling operation, so that the melt is cooled and crystallized according to the predetermined process requirements, and finally a single crystal silicon rod is formed; S6.2: The melt is spliced into a ring-shaped structure for crystal pulling, that is, the melts in multiple smelting tanks are converged into a ring-shaped structure, and uniform cooling and crystallization are performed through a ring-shaped melt crystal pulling mode to improve the stability of the melt and reduce crystal defects caused by uneven temperature, wherein the ring-shaped melt crystal pulling mode is connected through the liquid outlets between the multiple smelting tanks to realize the uniformity of the melt flow; S6.3: The melt is spliced into a spiral structure for crystal pulling, that is, the melt flows along a spiral trajectory and gradually enters the crystal pulling zone for cooling and crystallization to optimize the melt flow direction and temperature distribution and improve the quality of the single crystal silicon rod, wherein the spiral melt crystal pulling mode controls the flow rate of the melt in the spiral channel to maintain a stable temperature gradient before entering the crystal pulling zone.

[0021] Compared with the prior art, the beneficial effects of the present application are: 1. Compared with the single crucible smelting method in the prior art, all silicon particles are concentrated for smelting, which causes impurities to easily accumulate in the melt and difficult to disperse, ultimately affecting the purity of the single crystal silicon. The present application uses four independent smelting devices, each smelting tank smelts silicon particles independently, so that the volume of the melt is relatively small and the local temperature gradient is more obvious, thereby promoting the convection and stirring of the melt. In this case, the concentration of impurities in a single smelting tank is relatively low, and it is easier to be discharged from the melt by diffusion, convection or evaporation.

[0022] 2. Compared with the single crucible smelting method in the prior art, the quartz crucible is subjected to high temperature and erosion of the silicon melt for a long time, causing silicon oxide to dissolve into the melt, which not only shortens the service life of the crucible, but also may introduce oxygen impurities and affect the quality of the single crystal. The present application uses four independent smelting pieces, and the volume of the high-temperature melt received by each smelting tank is reduced, and the contact area between the melt and the smelting tank per unit time is relatively reduced, thereby reducing the dissolution of silicon oxide into the melt and reducing the thermal load and chemical corrosion intensity of the smelting tank.

[0023] 3、Compared with the single crucible smelting mode in the prior art, the smelting volume is large, the temperature gradient is obvious, the local temperature of the smelting is uneven, the temperature field fluctuation is large in the crystal pulling process, the stability of the crystal growth is affected, dislocations and defects may be caused, four independent smelting devices are adopted in the scheme, each smelting piece is separately provided with a heating piece, the temperature of each smelting tank can be controlled respectively, the problem of too large temperature gradient caused by the large volume smelting is avoided, meanwhile, the four smelting devices are uniformly arranged around the central axis of the silicon making cavity, the overall temperature field is more balanced, and the local overheating or overcooling is reduced. Since the silicon particles are respectively split into four equal parts of silicon particles for smelting, the smelting volume in each smelting piece is reduced, so that the temperature adjustment response is faster when the temperature is controlled by the heating piece, the temperature of the crystal growth interface can be more accurately controlled, and the quality stability of the single crystal is improved.

[0024] 4、In addition, four independent smelting tanks are adopted in the scheme, the crystal pulling operation can be carried out in parallel, and the intermittent stagnation problem caused by waiting for smelting supplement in the traditional single crucible smelting mode is avoided. In this way, not only the continuity of the crystal pulling is improved, but also the temperature can be controlled respectively by the heating piece in the multiple smelting tanks, more accurate process optimization is realized, the production efficiency is greatly improved, and the demand for large-scale single crystal silicon production is met. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a three-dimensional view of the smelting device of the application.

[0026] Figure 2 It is a three-dimensional view of the structure in the silicon making furnace of the application.

[0027] Figure 3 It is a three-dimensional view of the connection of the smelting piece and the fixing assembly of the application.

[0028] Figure 4 It is a three-dimensional view of the smelting piece of the application.

[0029] Figure 5 It is a three-dimensional view of another perspective of the smelting piece of the application.

[0030] Figure 6 It is a three-dimensional view of the smelting piece spliced into a ring body structure of the application.

[0031] Figure 7 It is a three-dimensional view of the smelting piece spliced into a spiral body structure of the application.

[0032] Figure 8 It is a three-dimensional view of the local structure in the smelting piece of the application.

[0033] Figure 9 It is a three-dimensional view of the full gear and half gear in the driving port of the application.

[0034] Figure 10 Partial structure three-dimensional diagram of the pushing part of the application.

[0035] Figure 11 Three-dimensional diagram of the linkage of the application.

[0036] Figure 12 Three-dimensional diagram of the lifting blocking part of the application.

[0037] Figure 13 Three-dimensional diagram of the rotating liquid scraping assembly of the application.

[0038] Icon: 1-silicon production furnace, 2-pulling crystal port, 3-melting device, 4-melting part, 5-heating part, 6-fixing assembly, 7-melting tank, 8-first rotating part, 9-rotating part, 10-second rotating part, 11-connection part, 12-communication assembly, 13-liquid inlet, 14-driving port, 15-liquid inlet blocking plate, 16-driving part, 17-liquid outlet, 18-liquid outlet blocking plate, 19-extended part, 20-lifting part, 21-lifting tank, 22-lifting port, 23-driving tooth plate, 24-half gear, 25-full gear, 26-sliding rack, 27-limiting tank, 28-first telescopic part, 29-limiting part, 30-third rotating part, 31-strengthening block, 32-pushing part, 33-lifting blocking part, 34-linkage, 35-first wedge surface, 36-second wedge surface, 37-rotating liquid scraping assembly, 38-pressing hole, 39-clamping groove, 40-positioning column, 41-fourth rotating part, 42-second telescopic part, 43-liquid scraping part, 44-clamping part, 45-upper resisting tank, 46-falling tank, 47-falling block, 48-upper resisting part, 49-upper pushing part, 50-fifth rotating part, 51-rotating part, 52-first fixing shaft, 53-second fixing shaft, 54-intermediate part. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the application more clear, the application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the application, and are not used to limit the application.

[0040] Example: Reference Figures 1 to 13As shown, a kind of silicon particle smelting device for single crystal silicon rod production is disclosed, including silicon making furnace 1, silicon making cavity is equipped in silicon making furnace 1;The top of silicon making cavity is detachably installed with furnace cover by bolt, and the furnace cover is opened with crystal pulling port 2, and crystal pulling port 2 and silicon making furnace 1 are interconnected;Four smelting devices 3 are equipped in silicon making furnace 1, and four smelting devices 3 are evenly arranged in silicon making cavity with the axis of silicon making furnace 1 as center;Smelting device 3 includes smelting piece 4, heating piece 5 and fixing assembly 6;The surface of smelting piece 4 is opened with smelting groove 7, to accommodate silicon particles and smelt;Optionally, heating piece 5 selects induction heater, and silicon particles are heated by electromagnetic induction, can provide uniform and rapid heating effect, so as to heat silicon particles in smelting groove 7, make silicon particles melt;One end of fixing assembly 6 is connected with smelting piece 4, and the other end is connected to the inner wall of silicon making cavity, to support smelting piece 4.

[0041] Technical principle: The silicon particles are respectively split into four equal parts of silicon particles, then are respectively placed into corresponding smelting groove 7, then corresponding smelting piece 4 is heated by each heating piece 5, so that silicon particles are melted, and then crystal pulling operation is carried out through crystal pulling port 2.

[0042] Technical effect: In prior art, single crucible smelting method usually adopts a large-capacity smelting cavity, so that all silicon particles are simultaneously melted in the same space.However, since the whole melt is in the same heating environment, the internal temperature gradient is small, resulting in weak melt convection.In this case, impurities in the melt are difficult to diffuse fully, and are prone to accumulate in local area, especially in the later smelting stage, part of impurities may be retained in the melt due to density difference or surface tension effect, finally enter the single crystal silicon rod, affecting its purity.The present scheme adopts four independent smelting devices 3, and each smelting groove 7 smelts silicon particles independently, so that the volume of melt is relatively small, and the local temperature gradient is more obvious, thereby promoting the convection and stirring of the melt.In this case, the concentration of impurities in a single smelting groove 7 is relatively low, and is more easily removed from the melt by diffusion, convection or evaporation.For example, low-boiling-point impurities can more easily reach the escape condition in a smaller smelting cavity, while high-density metal impurities can more easily settle at the bottom of the melt and be removed.

[0043] Compared with the single crucible smelting method in prior art, the quartz crucible is subjected to high temperature and corrosion of silicon melt for a long time, resulting in the dissolution of silicon oxide into the melt, not only shortening the service life of the crucible, but also possibly introducing oxygen impurities, affecting the quality of single crystal.The present scheme adopts four independent smelting pieces 4, and the volume of high-temperature melt that each smelting groove 7 bears is reduced, and the contact area between the melt and smelting groove 7 per unit time is relatively reduced, thereby reducing the dissolution of silicon oxide into the melt, and reducing the thermal load and chemical corrosion intensity of smelting groove 7.

[0044] Compared with the single crucible smelting method in the prior art, the large volume of the melt and the obvious temperature gradient cause the local temperature of the melt to be uneven, resulting in large temperature field fluctuations during the crystal pulling process, affecting the stability of crystal growth, and possibly causing dislocations and defects. The present scheme adopts four independent smelting devices 3, each smelting piece 4 is separately provided with a heating piece 5, the temperature of each smelting tank 7 can be controlled separately, avoiding the problem of too large temperature gradient caused by large volume of melt. At the same time, due to the uniform arrangement of the four smelting devices 3 around the central axis of the silicon making cavity, the overall temperature field is more balanced, reducing the local overheating or supercooling. Since the silicon particles are respectively split into four equal parts of silicon particles for smelting, the volume of the melt in each smelting piece 4 is reduced. Therefore, when the temperature is controlled by the heating piece 5, the temperature adjustment response is faster, and the temperature of the crystal growth interface can be more accurately controlled, improving the quality stability of the single crystal.

[0045] In addition, the present scheme adopts four independent smelting tanks 7, which can perform crystal pulling operations in parallel, avoiding the intermittent stagnation problem caused by waiting for melt replenishment in the traditional single crucible smelting method. In this way, not only the continuity of crystal pulling is improved, but also the temperature in each smelting tank 7 can be controlled by the heating piece 5, achieving more precise process optimization, thereby greatly improving production efficiency and meeting the demand for large-scale single crystal silicon production.

[0046] Reference Figure 3 As shown in the figure, in the present embodiment, each smelting piece 4 is in a ring-fan shape structure; the fixing assembly 6 includes a first rotating piece 8, a rotating part 9, a second rotating piece 10 and a connecting part 11; the first rotating piece 8 is fixed on the inner wall of the silicon making cavity and has a first rotating end; one end of the rotating part 9 is fixedly connected with the first rotating end, and the rotating part 9 is arranged in a direction perpendicular to the axis of the first rotating end; the second rotating piece 10 is arranged in a direction parallel to the first rotating piece 8 and has a second rotating end, and the second rotating piece 10 is fixed to the other end of the rotating part 9; one end of the connecting part 11 is connected with the smelting piece 4, and the other end is connected with the second rotating end, and the connecting part 11 is arranged in a direction perpendicular to the axis of the second rotating end; the first rotating piece 8 and the second rotating piece 10 are both servo motors, which are closed-loop controlled and combined with encoders (incremental or absolute), so as to realize high-precision position, speed and torque control, and high-precision control.

[0047] Technical principle: Reference Figure 6 As shown in the figure, by controlling the rotation of the first rotating end of the first rotating piece 8, the rotating part 9 is driven to move, so as to adjust the position of the second rotating piece 10, and then the second rotating end of the second rotating piece 10 is controlled to rotate, driving the connecting part 11 to move the smelting piece 4, so as to sequentially splice the smelting pieces 4 to form a spliced ring-shaped smelting structure.

[0048] ReferenceFigure 4 、 5 As shown in FIG. 1 and FIG. 2, in the embodiment, the melting system further comprises a communication assembly 12 for communicating the melting tanks 7 of adjacent melting devices 4 to ensure uniform distribution of the melt during the melting process; the melting tank 7 has a ring-fan structure; specifically, the communication assembly 12 comprises a liquid inlet part and a liquid outlet part. The liquid inlet part comprises a liquid inlet 13, a driving port 14, an inlet baffle 15 and a driving member 16; the liquid inlet 13 and the driving port 14 are both arranged at one end of the melting device 4, and the top wall of the liquid inlet 13 is provided with a liquid inlet groove; the driving port 14 is located above the liquid inlet 13 and communicates with the liquid inlet groove; the inlet baffle 15 is slidingly connected in the liquid inlet groove in the height direction and can block the liquid inlet 13; the driving member 16 is arranged in the driving port 14 and is used to drive the inlet baffle 15 to slide in the liquid inlet groove. The liquid outlet part comprises a liquid outlet 17, an outlet baffle 18 and a starting assembly; the liquid outlet 17 is arranged at the other end of the melting device 4, and the top wall of the liquid outlet 17 is provided with a liquid outlet groove; the outlet baffle 18 is slidingly connected in the liquid outlet groove in the height direction, and the sliding direction is parallel to that of the inlet baffle 15. The starting assembly is used to control the linkage of the inlet baffle 15 and the outlet baffle 18, and comprises a stretching member 19 and a lifting member 20; the stretching member 19 is connected to one end of the melting device 4 and is located above the liquid outlet groove; one end of the lifting member 20 is connected to the inlet baffle 15 and can drive the outlet baffle 18 in the adjacent melting device 4 to move; specifically, the two ends of the melting device 4 are both provided with lifting grooves 21 in the height direction, one of which communicates with the liquid inlet groove and the liquid inlet 13, and the other of which communicates with the liquid outlet groove and the liquid outlet 17; the outer side wall of the outlet baffle 18 is provided with a lifting port 22.

[0049] Optionally, a spring damper is connected between the upper end of the inlet baffle 15 and the liquid inlet groove, and a spring damper is connected between the upper end of the outlet baffle 18 and the liquid outlet groove. In the closed state, the spring damper can provide additional sealing force to ensure that the inlet baffle 15 and the outlet baffle 18 are tightly attached to the liquid inlet groove and the liquid outlet groove, respectively, to prevent the melt from leaking due to thermal expansion or slight vibration, thereby improving the safety and stability of the melting system.

[0050] Technical principle: Reference Figure 6As shown, when the smelting pieces 4 in the smelting device 3 are sequentially spliced, the protruding piece 19 enters the driving port 14, and the driving piece 16 is started to make the inlet baffle 15 press the spring damper and slide into the liquid inlet groove to unblock the liquid inlet port 13; at the same time, when the inlet baffle 15 slides into the liquid inlet groove, the lifting piece 20 is clamped into the lifting port 22 of the outlet baffle 18, which can synchronously drive the outlet baffle 18 in the adjacent smelting piece 4 to press the spring damper and slide into the liquid outlet groove upward to unblock the corresponding liquid outlet port 17, so that the liquid inlet port 13 and the liquid outlet port 17 are both in an open state, and the melt in the original single smelting piece 4 can contact with the adjacent melt to realize mutual communication.

[0051] Technical effects: During the smelting process of each smelting piece 4, the natural convection of the melt is usually slow, which may cause some impurities to stay in the local area for a long time, affecting the purity of the final single crystal silicon. Through the cooperation of the first rotating piece 8 and the second rotating piece 10 in the fixed assembly 6, the rotating part 9 and the connecting part 11 can be driven to move the smelting piece 4, so that the connected smelting bodies are shaken synchronously, which can actively enhance the fluidity of the melt in the connected smelting tank 7, accelerate the diffusion and dilution of impurities, and make them more uniformly distributed in the melt, avoiding local enrichment of impurities. In addition, the enhanced melt flow can also promote the floating or deposition of insoluble impurities at the bottom of the smelting tank 7, thereby further reducing the impact of impurities on the quality of single crystal silicon and improving the stability of crystal pulling and the purity of the final product.

[0052] In the traditional smelting method, the problem of large temperature gradient will affect the stable growth of single crystal, especially in the local high temperature or low temperature area, which may cause thermal stress and structural defects during the crystal pulling process. By synchronously shaking the connected smelting bodies, a dynamic stirring effect is achieved, which makes the melt flow more fully, can accelerate the uniform distribution of heat in the melt, reduce the temperature gradient, and avoid the phenomenon of local overheating or undercooling. This dynamic stirring effect can make the melt always maintain a stable thermal field environment, providing better temperature conditions for the stable growth of single crystal silicon, reducing dislocations, inclusions and other defects, and improving the quality of the crystal.

[0053] During the crystal pulling process, the replenishment and fluidity of the melt have a direct impact on production efficiency. Under the traditional method, when the silicon melt in a smelting piece 4 is almost consumed, additional material needs to be added and melted, and although the simple connection of the melt can alleviate this problem to some extent, the melt flow is still limited by natural diffusion. By using the structure of synchronously shaking smelting bodies, the flow and replenishment speed of the melt can be significantly accelerated, ensuring that the exchange of melt between smelting tanks 7 is more efficient, so that the crystal pulling process is not interrupted due to local depletion of the melt. This not only improves the continuity of production, but also reduces the waiting time, improves the overall yield of single crystal silicon and production efficiency.

[0054] ReferenceFigure 8 、 9 As shown in FIGS. 16 and 17, in the embodiment, the driving member 16 includes a driving toothed plate 23, a half gear 24, a full gear 25, and a sliding rack 26; the driving toothed plate 23 is slidingly connected to the driving port 14 and can extend into the liquid inlet groove; two parallel rotating shafts are fixed between the side walls of the driving port 14; the half gear 24 is rotatably sleeved on one of the rotating shafts and engages with the driving toothed plate 23; the full gear 25 is rotatably sleeved on the other rotating shaft and can engage with the half gear 24; the sliding rack 26 is slidingly connected in the liquid inlet groove and connected to the inlet baffle 15 beside the spring damper; one side of the sliding rack 26 engages with the full gear 25.

[0055] Technical principle: In the initial state, under the action of the spring damper, the inlet baffle 15 blocks the liquid inlet 13, at this time, the driving toothed plate 23 is located in the driving port 14, when the extending member 19 enters the driving port 14 and pushes the driving toothed plate 23 to move, the driving half gear 24 rotates, and then delays the rotation of the full gear 25 to drive the sliding rack 26 to move, finally drives the inlet baffle 15 to slide into the liquid inlet groove, and at the same time, under the action of the lifting member 20 in the above scheme, the outlet baffle 18 can slide into the liquid outlet groove, realizing the splicing of the melting members 4 and the intercommunication of the adjacent melting grooves 7.

[0056] Technical effect: The driving toothed plate 23 gradually transmits power under the pushing of the extending member 19, first through the half gear 24, then through the full gear 25, and finally drives the sliding rack 26 to move stably, so that the inlet baffle 15 enters the liquid inlet groove, ensuring the smooth opening of the liquid inlet 13 and the liquid outlet 17. At the same time, the synchronous action of the lifting member 20 makes the outlet baffle 18 slide into the liquid outlet groove at the same time, realizing the synchronous intercommunication between the melting grooves 7. This precise linkage control mechanism not only eliminates the time lag of the fusion of the melts in different melting grooves 7, but also makes the melts flow and mix more uniformly, ensuring the consistency of the raw materials in the crystal pulling process and improving the quality of the single crystal silicon rod.

[0057] At the same time, the cooperation of the full gear 25 and the half gear 24 forms a time delay mechanism after the extending member 19 enters the driving port 14. Specifically, the teeth of the half gear 24 do not engage with the sliding rack 26 in the initial stage, but after a period of rotation, they gradually form an engagement relationship with the sliding rack 26, thereby driving the inlet baffle 15 to slide into the liquid inlet groove and unblock the liquid inlet 13. This delayed opening design can effectively prevent the inlet baffle 15 and the outlet baffle 18 from being opened simultaneously when the extending member 19 just enters the driving port 14, thereby preventing the sudden flow or overflow of the melts due to premature intercommunication, and improving the stability and safety of the melting process.

[0058] In addition, if the inlet baffle 15 and the outlet baffle 18 are opened at the moment when the extension piece 19 just enters the driving port 14, the melt will form a large flow mutation in a short time. Because the silicon melt has high surface tension and viscosity, such a sudden flow may cause a sudden drop or rise in the local melt temperature, thereby affecting the uniformity of the crystal in the crystal pulling process. In the present scheme, the design of the full gear 25 and the half gear 24 makes the inlet baffle 15 gradually slide into the liquid inlet groove after a time delay, and the outlet baffle 18 is synchronously unblocked, and the melt is gradually connected at a small flow rate, thereby reducing the sudden flow phenomenon and improving the stability of the melt.

[0059] In the single crystal silicon growth process, the uniformity of the melt plays a decisive role in the quality of the crystal. If the melt flow rate is too fast, the melts in different smelting pieces 4 will collide violently, which may cause a violent disturbance of the temperature field, resulting in a local region being undercooled or overheated, affecting the nucleation and growth stability of the single crystal silicon. In the present scheme, with the slow sliding of the inlet baffle 15, the liquid inlet 13 is gradually opened, and the melt gradually flows into the adjacent smelting tank 7, forming a laminar steady flow, so that the melts in different smelting pieces 4 can be slowly mixed, thereby reducing the temperature field fluctuation, making the melt temperature more uniform, and further improving the quality of the single crystal silicon.

[0060] In the high-temperature smelting process, there is a thermal convection phenomenon in the melt. If the melt flow rate is too fast, it will cause a local temperature to fluctuate violently, resulting in uneven thermal stress in the crystal pulling process, which may induce dislocation defects. In addition, the impurities (such as oxygen, carbon, metal impurities, etc.) in the silicon melt are often unevenly distributed, and the rapid flow may cause the redistribution of impurities, affecting the purity of the single crystal silicon. The present scheme gradually opens and closes, making the mixing and flow process of the melt more controllable, reducing the turbulent effect, avoiding the enrichment of impurities in the local area, ensuring the uniformity of the melt composition in the crystal pulling process, and improving the purity and quality of the final single crystal silicon.

[0061] Reference Figure 2 、 3 As shown in FIG. 1, in the present embodiment, the inner side wall of the silicon production furnace 1 is provided with four limiting grooves 27 along the height direction; the fixing assembly 6 further includes a first telescopic piece 28 and a limiting piece 29. Specifically, the first telescopic piece 28 is a hydraulic cylinder, and the first telescopic piece 28 is fixed in the silicon production furnace 1 along the height direction and has a telescopic first telescopic end; the limiting piece 29 is slidably connected in the limiting groove 27, and the first rotating piece 8 is fixed on one end of the limiting piece 29 outside the limiting groove 27, and the bottom side is fixed with the first telescopic end.

[0062] Because the internal temperature distribution of silicon furnace 1 is crucial to the quality of single-crystal silicon, the installation position of melting element 4 directly affects the temperature uniformity of the melt. This solution, by controlling the movement of the first telescopic end of first telescopic element 28, thereby driving limiter 29 to slide along limiter groove 27, allows for flexible adjustment of the height and position of melting element 4, ensuring that melting element 4 is always located in the optimal thermal distribution area. This results in more uniform melting of silicon particles, reduced temperature gradients, and improved single-crystal silicon quality.

[0063] refer to Figure 7 As shown, in this embodiment, the smelting piece 4 in the smelting device 3 is sequentially spliced ​​to form a spiral structure under the action of the fixing assembly 6; the fixing assembly 6 also includes a third rotating member 30, specifically a servo motor, which is arranged parallel to the end of the connecting portion 11 away from the second rotating member 10 and has a rotatable third rotating end; a reinforcement block 31 is installed on the outside of the smelting piece 4, and the smelting piece 4 is fixedly connected to the third rotating end through the reinforcement block 31.

[0064] Technical principles and effects: The third rotating member 30 can drive the smelting member 4 to swing a certain angle around the axis of the third rotating end and then swing back. In traditional single melting crucibles, due to the large melt and limited heating methods, the temperature gradient is often large, resulting in uneven thermal field distribution within the melt, which in turn affects the stable growth of single crystal silicon. In contrast, this solution uses four smelting members 4 to melt silicon particles separately. The third rotating member 30 then controls the smelting members 4 to oscillate periodically, creating dynamic flow within the melt and mixing the high-temperature and low-temperature melts, thereby reducing local temperature gradients and improving overall temperature uniformity.

[0065] In addition, the flow of the melt can also promote the migration of impurities to the surface or edge of the melt, facilitating subsequent removal and further improving the purity of single crystal silicon.

[0066] refer to Figures 10-12 As shown, in this embodiment, a pusher assembly is provided in the smelting tank 7; the pusher assembly includes a pusher portion 32, a lifting member 33 and a linkage member 34; the pusher portion 32 is slidably arranged along the annular sector track of the smelting tank 7; the lifting member 33 includes two arc-shaped lifting bars and is located between the liquid outlet trough and the pusher portion 32, one end of the lifting member 33 is connected to the pusher portion 32, and the other end has a first wedge surface 35; the side of the discharge baffle 18 close to the pusher portion 32 has a second wedge surface 36 corresponding to the first wedge surface 35; the linkage member 34 is used to connect the lifting member 33 in two adjacent smelting pieces 4 to the other pusher portion 32; A rotating scraping assembly 37 is provided in the silicon making furnace 1 . The rotating scraping assembly 37 is arranged along the axis in the silicon making furnace 1 and is used to drive the pushing portion 32 at the highest position to slide along a circular sector track.

[0067] Technical principles: By rotating the liquid scraping assembly 37, the highest position of the pushing part 32 is driven to slide along the ring-fan-shaped track of the smelting tank 7, synchronously driving the connected stopper 33 to move, so that the first wedge-shaped surface 35 acts on the second wedge-shaped surface 36, pushing the baffle 18 to slide into the liquid outlet groove to release the blockage of the liquid outlet 17, so that the melt in the highest position of the smelting tank 7 flows to the adjacent smelting tank 7 through the liquid outlet 17, and under the action of the linkage 34, when one pushing part 32 slides, it will synchronously drive the pushing part 32 of the adjacent smelting tank 7, realizing the sequential flow of the melt, and finally converging into the lowest position of the smelting tank 7.

[0068] Technical effects: In the traditional smelting process, the melt may form local retention due to surface tension, viscosity and other factors, causing poor flow and affecting smelting efficiency. The present scheme gradually opens the liquid outlet 17 by the pushing assembly, so that the melt flows step by step according to the designed track, realizes precise melt delivery, and avoids melt retention problem. With the step-by-step flow of the melt, the melt in each smelting tank 7 is constantly redistributed and merged, which can further homogenize the temperature field and composition distribution.

[0069] Compared with the static smelting mode in the prior art, this dynamic flow mechanism helps to reduce local enrichment of impurities, improve the purity of monocrystalline silicon and the stability of the crystal pulling process. The melt finally converges into the lowest position of the smelting tank 7, which helps to form a stable melt pool and provides uniform and stable melt supply for the crystal pulling process.

[0070] When the melt flows to the adjacent smelting tank 7, the heat exchange between the melts will promote the temperature field to be uniform, reducing local undercooling or overheating area. This way from smelting to flow, and then to convergence can ensure that the thermal field in the crystal pulling process is more uniform, avoiding the problem that the melt temperature is not uniform, which makes it easy to form grain boundary defects such as dislocation and stress concentration in the crystal pulling process, thereby improving the quality and yield of monocrystalline silicon rods.

[0071] Reference Figure 5 , 10 As shown in the figure, in the present embodiment, the pushing part 32 is provided with an extrusion hole 38 above the smelting tank 7.

[0072] Technical principles: In this scheme, the synchronous sliding of the pushing part 32 in the smelting tank 7 is realized through the action of the linkage 34, ensuring that the melt can flow to the adjacent smelting tank 7 in turn. However, after the melt in the high-position smelting tank 7 enters the adjacent smelting tank 7, there may still be some melt remaining in the smelting tank 7, causing incomplete melt flow. To effectively solve this problem, the extrusion hole 38 is added in the design, and the rotating liquid scraping assembly 37 is matched, so that the pushing part 32 can reciprocate along the ring-fan-shaped trajectory of the smelting tank 7. Specifically, when the pushing part 32 moves reversely, it will press the new melt flowing in at the high position to the liquid inlet plate. As the pushing part 32 gradually moves, the space of the melt gradually decreases, increasing the pressure of the melt. When the height of the melt rises to the position of the extrusion hole 38, the melt enters the other side of the pushing part 32 through the extrusion hole 38, completing the reflow of the melt. Then the forward sliding of the pushing part 32 pushes the melt to the liquid outlet 17, so as to enter the next smelting tank 7, and finally gather in the smelting tank 7 at the lowest position.

[0073] Technical effects: By setting the extrusion hole 38 and the rotating liquid scraping assembly 37, combined with the reciprocating sliding of the pushing part 32, it is ensured that the melt can gradually flow and enter the adjacent smelting tank 7, avoiding the problem of melt residue. The melt in the high-position smelting tank 7 is pushed to the liquid inlet plate by the reversely moving pushing part 32, so that the melt is compressed in a limited space, which to some extent promotes the efficient flow of the melt. Since the sliding process of the pushing part 32 gradually increases the flow pressure of the melt, it helps to reduce the melt retention in the smelting tank 7, ensuring smooth transmission of the melt. At the same time, the design of the extrusion hole 38 further ensures that the melt can flow through the hole, reducing the residue of the melt. After the melt completely flows into the next smelting tank 7, it can effectively reduce the local accumulation. Through these designs, the uniformity of the melt is improved to some extent, avoiding uneven heating and impurity enrichment caused by melt retention, thereby providing stable melt flow for the subsequent crystal pulling process.

[0074] Reference Figure 2 、 4, 13, in the embodiment, the push part is provided with a clamping groove 39; the rotating liquid scraping assembly 37 comprises a positioning column 40, a fourth rotating part 41, a second telescopic part 42 and a liquid scraping part 43; the positioning column 40 is arranged in the silicon production furnace 1 along the axis direction of the silicon production furnace 1; the fourth rotating part 41 is fixed on the positioning column 40 and has a fourth rotating end which can rotate, and the fourth rotating part 41 is a servo motor; the second telescopic part 42 is arranged on the fourth rotating end and has a second telescopic end which can be telescopic, and the second telescopic part 42 is a hydraulic cylinder; one end of the liquid scraping part 43 is arranged on the second telescopic end, and the liquid scraping part 43 is arranged along the horizontal direction, and the other end has a clamping part 44 which can be clamped into the clamping groove 39, and the shapes of the clamping groove 39 and the clamping part 44 are both cylindrical structures, so that the clamping part 44 can be clamped into any clamping groove 39 of the four push parts 32.

[0075] Technical principle: By controlling the elongation of the second telescopic end of the second telescopic part 42, the liquid scraping part 43 is driven to move along the preset track, so that the clamping part 44 gradually approaches and is located directly above the clamping groove 39. When the liquid scraping part 43 reaches the specified position, the second telescopic end is controlled to be shortened, so that the clamping part 44 is accurately clamped into the corresponding clamping groove 39, thereby forming the linkage connection between the clamping part 44 and the push part 32. On this basis, the fourth rotating end of the fourth rotating part 41 is further controlled to rotate, so that the torque is transmitted to the liquid scraping part 43 through the second telescopic part 42, and finally the push part 32 is driven along the ring-fan-shaped track of the smelting groove 7 by the clamping part 44 of the liquid scraping part 43, realizing the accurate driving of the push part 32 and the flow control of the melt.

[0076] Technical effect: This driving mode based on clamping linkage can ensure that the push part 32 remains stable connection during driving, avoiding deviation or failure caused by inertia or gap problems. When the action of the second telescopic part 42 is accurately controlled to elongate and shorten, the clamping part 44 of the liquid scraping part 43 can be accurately embedded in the clamping groove 39 at the appropriate time, ensuring effective transmission of driving force, thereby improving the reliability of the sliding of the push part 32. In addition, through the torque transmission of the fourth rotating part 41, the non-uniformity of the force directly borne by the push part 32 can be reduced, so that it slides more smoothly in the smelting groove 7, thereby optimizing the stability of the melt flow. During the sliding of the push part 32 along the ring-fan-shaped track, the melt can be orderly guided to flow to the adjacent smelting groove 7, reducing the local temperature difference caused by uneven melt flow.

[0077] During the melt flow process, the pushing part 32 slides along the ring-fan-shaped track of the smelting tank 7, can effectively drive the melt to enter the adjacent smelting tank 7 in turn, and can keep the melt in a dynamic flow state, thereby avoiding the melt to be static in the smelting tank 7 for a long time and reducing the accumulation of local temperature gradient. Since the uniformity of the melt temperature is crucial to the crystal pulling process, if the melt has obvious uneven temperature distribution, it may cause the unstable crystal growth rate in the crystal pulling process, and even cause the problems such as heat stress concentration and dislocation defect increase, thereby affecting the quality of the single crystal silicon. Therefore, by sliding the pushing part 32 to drive the melt flow, the temperature uniformity of the melt can be continuously optimized, the situation of local high or low temperature can be avoided, and the stability of the thermal field in the crystal pulling process can be improved.

[0078] Reference Figures 10-12 As shown in the figure, in the embodiment, the linkage 34 includes an upper abutting groove 45, a lower falling groove 46, a lower falling block 47, an upper abutting part 48 and an upper pushing part 49; the upper abutting groove 45 is opened on the top side of the pushing part 32; the lower falling groove 46 is opened on the bottom side of the blocking part 33 and can be aligned with the upper abutting groove 45; the lower falling block 47 is slidingly arranged in the lower falling groove 46 and can slide into the lower falling groove 46 along the direction of gravity after the upper abutting groove 45 and the lower falling groove 46 are aligned, so as to realize the linkage connection; optionally, the top wall of the lower falling block 47 and the lower falling groove 46 is connected through a spring damper, and after the upper abutting groove 45 and the lower falling groove 46 are aligned, the lower falling block 47 can slide into the lower falling groove 46 along the direction of gravity under the action of the spring damper, without the intervention of additional external force, so as to simplify the alignment process; the upper abutting part 48 is slidingly arranged in the upper abutting groove 45; the upper pushing part 49 is arranged in the upper abutting groove 45, so as to control the release or locking of the lower falling block 47.

[0079] The upper pushing part 49 includes a fifth rotating part 50, a rotating part 51, a first fixed shaft 52, a second fixed shaft 53 and an intermediate part 54; the fifth rotating part 50 is arranged in the upper abutting groove 45 and has a fifth rotating end which can rotate, and the fifth rotating part 50 is a servo motor; the rotating part 51 is fixedly connected with the fifth rotating end and is used for rotating with the fifth rotating end; the first fixed shaft 52 is arranged on the rotating part 51 along the direction parallel to the fifth rotating end, and the first fixed shaft 52 and the rotating part 51 are arranged eccentrically; the second fixed shaft 53 is fixedly arranged on the upper abutting part 48 along the direction parallel to the first fixed shaft 52; one end of the intermediate part 54 is rotatably sleeved on the first fixed shaft 52, and the other end is rotatably sleeved on the second fixed shaft 53, and is used for sliding the upper abutting part 48 when the rotating part 51 rotates, so as to control the release or locking of the lower falling block 47.

[0080] Technical principle: Before the rotation of the liquid scraping assembly 37 is started, the upper pushing piece 49 in the lowest pushing part 32 is controlled to work. Specifically, the rotation of the fifth rotating piece 50 drives the rotating part 51 to rotate, the first fixed shaft 52 rotates, the intermediate piece 54 is further driven to move, the upper blocking block is driven to slide upward along the upper blocking groove 45 under the action of the second fixed shaft 53, and finally the upper blocking block blocks the notch of the upper blocking groove 45.

[0081] The purpose of this is to prevent the falling block 47 of the upper melting tank 7 from being clamped into the upper blocking groove 45 due to gravity, thereby ensuring that the blocking piece 33 of the lowest melting tank 7 will not trigger the opening of the liquid outlet 17 in the linkage process, thereby avoiding the accidental leakage of the melt gathered into the lowest melting tank 7.

[0082] Subsequently, the rotation of the liquid scraping assembly 37 is controlled to be started, and the pushing part 32 at the highest position drives the blocking piece 33 to pass through the liquid outlet 17. When the falling groove 46 is aligned with the upper blocking groove 45 of the adjacent pushing part 32, the falling block 47 slides into the upper blocking groove 45 in the direction of gravity under the action of the spring damper, the linkage control of the adjacent pushing part 32 is realized, the melt in the melting tank 7 at the high position flows in sequence, and finally flows into the melting tank 7 at the lowest position.

[0083] Technical effects: By ensuring that the blocking piece 33 of the lowest melting tank 7 stably controls the opening and closing of the liquid outlet 17 in the linkage process, the melt can be strictly controlled to flow according to the set process, so that the transfer process of the melt between different melting tanks 7 is carried out in the order as intended, and the sudden change of the melt flow state caused by uncontrolled leakage is avoided. In the case of stable melt flow, the temperature distribution in different melting tanks 7 can be gradually adjusted to a state of tend to be uniform, reducing the possibility of local melt temperature mutation, thereby reducing the uneven crystal growth phenomenon caused by excessive temperature gradient change. At the same time, in the process of controlled flow, impurities will gradually diffuse with the normal flow of the melt, and will not be enriched in local areas due to turbulent effects or sudden flow changes, thereby maintaining the uniformity of the melt composition, so that the subsequent crystal pulling process can be carried out in a more stable melt environment. With the optimization of the melt flow state and the uniformity of the impurity distribution, the final single crystal silicon crystal quality is improved, and the crystal defects caused by abnormal impurity concentration or temperature change are reduced to some extent, and the yield is improved.

[0084] Another purpose of the present application is to provide a method for using a silicon particle melting device for single crystal silicon rod production, comprising the following steps: S1: raw material preparation The polycrystalline silicon is screened according to a predetermined proportion, impurities and oversized or undersized particles are removed, and the particle size is ensured to be uniform.

[0085] S2: preheating of the melting device 3 Start heating element 5, and raise the temperature of smelting element 4 to an initial heating temperature (e.g. 800-1000℃) to avoid splashing or oxidation of polycrystalline silicon caused by sudden heating.

[0086] S3: Silicon particle feeding Under the protection of an inert gas (e.g. argon), the screened silicon particles are slowly fed into the four smelting tanks 7 in batches, ensuring uniform feeding and avoiding local overheating or clumping.

[0087] S4: Temperature control and smelting Gradually increase the heating temperature to above the melting point of silicon (about 1420-1600℃), while monitoring the temperature of smelting element 4 in real time through an external temperature control system to avoid evaporation or oxidation of silicon caused by overheating.

[0088] S5: Stirring and homogenization Use the third rotating element 30 to drive smelting element 4 to oscillate at a certain angle around the axis of the third rotating end, and then oscillate back, forming dynamic flow inside the melt, and mixing the melt in the high-temperature zone and the low-temperature zone, thereby reducing the local temperature gradient and improving the quality of the melt.

[0089] S6: Melt convergence and crystal pulling process The melt convergence and crystal pulling process includes any of the following: S6.1: Melt does not converge, and crystal pulling is performed separately When the melt does not converge, independent crystal pulling operations are performed on the melt in each smelting tank 7. The melt is individually guided to the crystal pulling zone, where it is cooled, crystallized, and gradually forms a single crystal silicon rod according to the predetermined process requirements.

[0090] S6.2: Melt is spliced into a ring-shaped structure, and crystal pulling is performed When the melts in multiple smelting tanks 7 are spliced into a ring-shaped structure, the melt will converge in a ring shape in the smelting tank 7. Through the ring-shaped crystal pulling method, the melt is uniformly cooled in the temperature control zone to form a single crystal silicon rod. This method can effectively improve the stability of the melt and avoid defects caused by uneven temperature.

[0091] S6.3: Melt is spliced into a spiral structure, and crystal pulling is performed When the melt is spliced into a spiral structure, the melt will flow along the spiral trajectory and be guided to the crystal pulling zone for gradual cooling and crystallization during the process. The spiral structure helps to further optimize the direction of melt flow and temperature distribution, ensuring uniform cooling of the melt during the crystal pulling process and the generation of high-quality single crystal silicon.

[0092] Technical effects: In the production of single crystal silicon rods, the temperature uniformity of the melt directly affects the quality of the crystal pulling. If the melt is locally overheated, it can cause excessive evaporation of the silicon liquid, leading to composition segregation; if the melt is locally too cold, it can form polycrystalline regions due to premature crystallization, affecting the quality of the single crystal. Therefore, by selecting an appropriate melt convergence mode, the thermal distribution characteristics of the melt can be optimized. For example, in the melt non-convergence mode, each smelting tank 7 is independently heated, which is relatively suitable for process requirements that require precise control of the local melt composition and temperature.

[0093] In the ring or spiral convergence mode, the melts of multiple smelting tanks 7 exchange heat with each other through flow, reducing the temperature difference of the overall melt and avoiding the phenomenon of local overheating or undercooling. In particular, the spiral convergence mode, due to the extension of the flow path of the melt, makes the heat conduction more sufficient, which can further reduce the temperature gradient and improve the uniformity of the single crystal silicon rod.

[0094] In the crystal pulling process, the flow and stability of the melt are crucial to the growth of the single crystal. If the melt flows violently or there is an unstable temperature gradient, it can cause fluctuations in the crystal interface, which in turn affects the crystallization quality of the single crystal silicon rod. For example, in the traditional single-tank melt crystal pulling method, the flow direction of the melt is relatively single, which is easy to cause thermal stress due to local temperature changes, thereby causing grain boundary defects.

[0095] Through the ring or spiral melt convergence mode, the flow of the melt is more stable. The ring structure helps to form a closed melt circulation, making the melt temperature more uniformly maintained within the set range, reducing the generation of thermal stress. The spiral structure can further optimize the flow path of the melt, allowing it to maintain a smooth flow during the gradual cooling process, reducing disturbances to the crystal pulling interface, thereby reducing dislocation density and improving the integrity of the single crystal silicon.

[0096] In actual production, different crystal pulling processes require different melt supply modes. For example, in some specific application scenarios, different doping concentrations or different diameters of single crystal silicon rods need to be pulled, at which time the melt non-convergence mode can better meet the process requirements. In batch production, in order to improve production efficiency and reduce energy consumption, the melt is spliced into a ring or spiral shape for crystal pulling, which has more advantages.

[0097] The ring structure can realize multi-point liquid taking, improve equipment utilization, and reduce the energy consumption required for re-heating the melt. The spiral structure further extends the flow path of the melt, making the temperature distribution of the melt more uniform, reducing heat loss, and improving energy efficiency. At the same time, since the melt convergence mode optimizes the utilization rate of the melt, it reduces the generation of edge materials and improves the yield of single crystal silicon rods, thereby reducing production costs and improving economic benefits.

[0098] In addition, the design of multiple independent melting tanks 7 can further purify the melt in subsequent flow processes, which helps to reduce the residual impurities in the final single crystal.

[0099] In the spiral splicing structure, the melt flows through multiple melting tanks 7, which helps to prolong the purification time of the melt, so that the impurities have more time to settle or evaporate.

[0100] By setting a reasonable width of the melting tank 7 and the pushing speed of the pushing part 32, the flow rate of the melt can be controlled, so that the laminar or turbulent characteristics of the melt can be controlled, and the impurities can be separated according to different characteristics such as density and surface tension during the flow process. For example, light impurities may be dispersed with gas on the surface of the melt, and high-density impurities may be deposited along the wall or bottom of the flow channel, so as to realize the spatial separation of impurities.

[0101] Although the present application has been described herein with reference to the various illustrative embodiments thereof, it is understood that various other modifications and implementations can be devised by those skilled in the art which will fall within the principles of the application disclosed herein. More specifically, various modifications and improvements can be made to the components of the subject combination layout and / or the layout itself, within the scope of the disclosure, drawings and claims. In addition to the modifications and improvements to the components and / or layout, other uses will also be apparent to those skilled in the art.

Claims

1. A silicon granule melting device for producing single crystal silicon rods, characterized in that: The utility model provides a silicon production furnace, which comprises a silicon production cavity in the interior; a crystal pulling port is arranged at the top end of the silicon production cavity and is in communication with the silicon production cavity; two or more melting devices are arranged in the silicon production cavity and are uniformly arranged around the axis of the silicon production furnace; the melting device comprises a melting element, a heating element and a fixing assembly; the surface of the melting element is provided with a melting groove for accommodating silicon particles and melting; the heating element is arranged on the melting element and is used for heating the melting element; one end of the fixing assembly is connected to the melting element, and the other end is connected to the inner wall of the silicon production cavity to support the melting element. The melting element is in the shape of a ring sector; the fixing assembly comprises a first rotating element, a rotating part, a second rotating element and a connecting part; one end of the first rotating element is fixed to the inner wall of the silicon production cavity and is provided with a first rotating end; one end of the rotating part is fixedly connected to the first rotating end and is arranged in a direction perpendicular to the axis of the first rotating end; the second rotating element is arranged in parallel to the first rotating element and is provided with a second rotating end; the second rotating element is fixed to the other end of the rotating part; one end of the connecting part is connected to the melting element, and the other end is connected to the second rotating end; the connecting part is arranged in a direction perpendicular to the axis of the second rotating end; the first rotating element drives the rotating part to move, and the second rotating element drives the connecting part to move, so that the melting elements are sequentially connected to form a ring-shaped melting structure; the utility model also comprises a communication assembly for connecting the melting grooves of adjacent melting elements to ensure uniform distribution of the melt during the melting process. The melting groove is in the shape of a ring sector; the communication assembly comprises an inlet part, a driving part, an inlet baffle, a driving element, an outlet part, an outlet baffle and a starting assembly; the inlet part comprises an inlet port arranged at one end of the melting element, a top wall of the inlet port is provided with an inlet groove, a driving port is arranged above the inlet port and is in communication with the inlet groove, and the inlet baffle is slidably connected to the inlet groove and can block the inlet port; the driving element is arranged in the driving port and is used for driving the inlet baffle to slide in the inlet groove; the outlet part comprises an outlet port arranged at the other end of the melting element, a top wall of the outlet port is provided with an outlet groove, and the outlet baffle is slidably connected to the outlet groove and slides in a direction parallel to the inlet baffle; the starting assembly is used for controlling the linkage of the inlet baffle and the outlet baffle and comprises a protruding element, a lifting element and a driving element; one end of the protruding element is connected to one end of the melting element and is arranged above the outlet groove; one end of the lifting element is connected to the inlet baffle and can drive the outlet baffle in the adjacent melting element to move; when the melting elements in the melting device are sequentially connected, the protruding element enters the driving port, the driving element is started, the inlet baffle slides into the inlet groove, and the blocking of the inlet port is released; when the inlet baffle slides into the inlet groove, the outlet baffle in the adjacent melting element is driven by the lifting element to slide into the outlet groove, the blocking of the corresponding outlet port is released, and the melt is connected. The driving element comprises a driving toothed plate, a half gear, a full gear and a sliding rack; the driving toothed plate is slidably connected to the driving port and can extend into the inlet groove; the half gear is rotatably connected to the driving port and is in engagement with the driving toothed plate; the full gear is rotatably connected to the driving port and is in engagement with the half gear; the sliding rack is slidably connected to the inlet groove and is connected to the inlet baffle; one side of the sliding rack is in engagement with the full gear. ​ ​ ​ 2. The silicon particle melting apparatus for producing a single crystal silicon ingot according to claim 1, characterized by: ​ ​ ​ ​ ​ ​ ​ 3. The silicon particle melting apparatus for producing a single crystal silicon ingot according to claim 1 or 2, characterized by: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4. The silicon particle melting apparatus for producing a single crystal silicon ingot according to claim 3, characterized by: ​ ​ ​ ​ ​ When the extension piece enters the driving port and pushes the driving toothed plate to move, the driving half gear rotates, then the delay drives the full gear to rotate, so as to drive the sliding rack to move, and finally the inlet baffle slides into the liquid inlet groove, so as to unblock the liquid inlet.

5. The silicon particle melting apparatus for producing a single crystal silicon ingot according to claim 1, characterized by: The inner side wall of the silicon production furnace is provided with a plurality of limiting grooves in the height direction; the fixing assembly further comprises: A first telescopic member is fixed in the silicon production furnace in the height direction and has a first telescopic end that can be telescoped; A limiting member is slidably connected in the limiting groove and connected to the first rotating member on one side and connected to the first telescopic end on the other side.

6. The silicon particle melting apparatus for producing a single crystal silicon ingot according to claim 2, characterized by: The melting members in the melting device are sequentially connected to form a spiral structure under the action of the fixing assembly; the fixing assembly further comprises: A third rotating member is provided parallel to one end of the connecting part away from the second rotating member and has a third rotating end that can be rotated; the melting member is fixedly connected to the third rotating end.

7. The silicon particle melting apparatus for producing a single crystal silicon ingot according to claim 3, characterized by: The melting tank is provided with a pushing assembly; the pushing assembly comprises: A pushing part is slidably arranged along the ring-fan-shaped track of the melting tank; A blocking member is located between the liquid outlet groove and the pushing part and has one end connected to the pushing part and the other end having a first wedge surface; The side of the outlet baffle close to the pushing part has a second wedge surface corresponding to the first wedge surface; A linkage member is used to connect the blocking member and another pushing part in adjacent two melting members; The silicon production furnace is provided with: A rotating liquid scraping assembly is arranged in the silicon production furnace along the axis and is used to drive the pushing part at the highest position to slide along the ring-fan-shaped track; When the rotating liquid scraping assembly drives the pushing part at the highest position to slide, the blocking member is simultaneously moved, the first wedge surface acts on the second wedge surface, the outlet baffle is pushed to slide into the liquid outlet groove, the liquid outlet is unblocked, the melt in the melting tank flows to the adjacent melting tank through the liquid outlet, and finally converges into the melting tank at the lowest position.

8. The silicon particle melting apparatus for producing a single crystal silicon ingot according to claim 7, characterized by: The pushing part is provided with an extrusion hole above the melting tank.

9. The silicon particle melting apparatus for producing a single crystal silicon ingot according to claim 7, characterized by: The pushing part is provided with a clamping groove; the rotating liquid scraping assembly comprises: A positioning column is arranged in the silicon production furnace along the axis; A fourth rotating member is arranged on the positioning column and has a fourth rotating end that can be rotated; A second telescopic member is arranged on the fourth rotating end and has a second telescopic end that can be telescoped; A liquid scraping member has one end arranged on the second telescopic end and the other end having a clamping part that can be clamped into the clamping groove.

10. A method of using a silicon particle melting apparatus for producing a single crystal silicon ingot according to any one of claims 1 to 9, characterized by: The method comprises the following steps: S1: raw material preparation, the polysilicon is screened according to the predetermined proportion, the impurities and the too large or too small particles are removed, so as to ensure the uniformity of the particle size; S2: preheating of the melting device, starting the heating member, increasing the temperature of the melting member to the initial heating temperature, so as to avoid the splashing or oxidation of the polysilicon caused by sudden heating; S3: silicon particle feeding, under the inert gas protection environment, the screened silicon particles are slowly fed into a plurality of melting tanks in batches, so as to ensure uniform feeding and avoid local overheating or caking, wherein the inert gas is argon, so as to avoid the oxidation reaction of the silicon particles in the high temperature environment; S4: temperature control and melting, gradually increasing the heating temperature to above the melting point of silicon, and monitoring the temperature of the melting member in real time through the external temperature control system, so as to avoid the evaporation or oxidation of silicon caused by overheating; S5: stirring and homogenization, using a driving device to drive the melting piece to swing, so that the internal melt forms a dynamic flow, and the melt in the high temperature zone and the low temperature zone are mixed with each other, so as to reduce the local temperature gradient and improve the melt quality, wherein the swing angle of the melting piece is between 10° and 45°, so as to optimize the temperature uniformity inside the melt; S6: melt convergence and crystal pulling, using any of the following methods for crystal pulling: S6.1: the melt does not converge, and the crystal pulling is performed independently, that is, the melt in each melting tank is independently subjected to crystal pulling operation, so that the melt is cooled and crystallized according to the predetermined process requirements, and finally a single crystal silicon rod is formed; S6.2: the melt is spliced into a ring-shaped structure for crystal pulling, that is, the melts in multiple melting tanks are converged into a ring-shaped structure, and uniform cooling and crystallization are performed through a ring-shaped melt crystal pulling method, so as to improve the stability of the melt and reduce the crystal defects caused by uneven temperature, wherein the ring-shaped melt crystal pulling method is connected through the liquid outlets between the multiple melting tanks, so as to realize the uniformity of the melt flow; S6.3: the melt is spliced into a spiral structure for crystal pulling, that is, the melt flows along a spiral trajectory and gradually enters the crystal pulling zone for cooling and crystallization, so as to optimize the melt flow direction and temperature distribution and improve the quality of the single crystal silicon rod, wherein the spiral melt crystal pulling method controls the flow rate of the melt in the spiral channel, so that a stable temperature gradient is maintained before the melt enters the crystal pulling zone.

Images