A charging device and a single crystal furnace

Abstract

The utility model relates to the technical field of single crystal silicon pulling, and discloses a feeding device and a single crystal furnace. The feeding device is installed on the furnace body of the single crystal furnace. The single crystal furnace includes a quartz crucible arranged in the furnace body, and the quartz crucible is used to fill silicon liquid. The feeding device includes a shell, a multi-wafer silicon rod and a valve. The shell is installed on the outer wall of the furnace body. The side wall of the furnace body is provided with a connecting port. The bottom of the shell is connected with the interior of the furnace body through the connecting port. The valve is arranged at the connecting port to open or close the connecting port. The multi-wafer silicon rod is arranged inside the shell, and the multi-wafer silicon rod extends along the height direction of the furnace body, and the multi-wafer silicon rod can move relative to the furnace body along the height direction of the furnace body, so that a part of the multi-wafer silicon rod is immersed in the silicon liquid. The feeding device and the single crystal furnace disclosed in the utility model can improve production efficiency while realizing secondary feeding.

Description

Technical Field

[0001] The utility model relates to the technical field of single crystal silicon pulling, in particular to a feeding device and a single crystal furnace. Background Art

[0002] As the photovoltaic market recovers, the market demand for single crystal products is increasing, and the competition among manufacturers is becoming more and more fierce. In order to reduce costs, increasing the feed amount to pull longer single crystal silicon rods and one crucible with multiple rods has become the first choice for single crystal manufacturers. Since increasing the primary feed requires upgrading the quartz crucible, thermal system and even the main body of the single crystal furnace, the transformation is difficult and the cost investment is high, all manufacturers generally adopt the lower-cost secondary feed method.

[0003] Built-in secondary charging has the advantages of small changes to the furnace body and low cost, and is widely used. However, the existing built-in secondary charging method has a long charging cycle, a complicated charging process, and crystal pulling cannot be performed during the charging process, resulting in low production efficiency. Utility Model Content

[0004] The utility model provides a feeding device and a single crystal furnace, which can realize secondary feeding and improve production efficiency.

[0005] In a first aspect, the utility model provides a feeding device installed in a furnace body of a single crystal furnace, wherein the single crystal furnace comprises a quartz crucible arranged in the furnace body, wherein the quartz crucible is used to fill silicon liquid, and the feeding device comprises a housing, a multi-wafer silicon rod and a valve;

[0006] The shell is mounted on the outer wall of the furnace body, a communication port is provided on the side wall of the furnace body, the bottom of the shell is communicated with the interior of the furnace body through the communication port, and the valve is provided at the communication port to open or close the communication port;

[0007] The poly-wafer silicon rod is arranged inside the shell, and the poly-wafer silicon rod extends along the height direction of the furnace body. The poly-wafer silicon rod can move relative to the furnace body along the height direction of the furnace body so that a part of the poly-wafer silicon rod is immersed in the silicon liquid.

[0008] The feeding device provided by the utility model is installed on the outer wall of the furnace body of the single crystal furnace. The feeding device includes an outer shell and a multi-wafer silicon rod located in the outer shell. The connecting port of the outer shell and the furnace body is connected by a valve. Before the crystal pulling starts, the valve is closed. When the crystal pulling starts, the valve can be opened, and the multi-wafer silicon rod in the outer shell is moved into the furnace body, and a part of the multi-wafer silicon rod is immersed in the silicon liquid in the quartz crucible. The part of the multi-wafer silicon rod immersed in the silicon liquid can be melted to compensate for the silicon liquid consumption generated during the crystal pulling process, and the consumption of silicon liquid and the amount of silicon material melted can be balanced, thereby ensuring that the liquid level of the silicon liquid in the quartz crucible remains constant. The feeding device in the utility model can also realize feeding while pulling crystals, thereby improving production efficiency and ensuring the quality of single crystals.

[0009] In some possible implementations, the feeding device further includes a pulling mechanism fixed in the housing, and the pulling mechanism is used to drive the multi-wafer silicon rods to extend along the height direction of the furnace body.

[0010] In some possible implementations, the lifting mechanism has a speed control module, and the speed control module is used to make the multi-wafer silicon rod move at a uniform speed relative to the furnace body.

[0011] In some possible implementations, the feeding device further includes a gripping mechanism, one end of which is connected to the lifting mechanism, and the other end of which is used to clamp the multi-wafer silicon rod.

[0012] In some possible implementation schemes, a limiting structure is provided inside the shell, and the limiting structure is used to limit the movement of the grabbing mechanism along the height direction of the furnace body.

[0013] In some possible implementations, the valve is a gate valve.

[0014] In a second aspect, the utility model provides a single crystal furnace, comprising a furnace body, a crystal rod pulling mechanism, a quartz crucible and a feeding device as described in any possible implementation scheme of the first aspect, wherein the crystal rod pulling mechanism and the quartz crucible are both arranged inside the furnace body, and the feeding device is arranged on the outer wall of the furnace body.

[0015] In some possible implementation schemes, the shell and the furnace body are detachably connected. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of a structure in which multi-wafer silicon rods do not enter the furnace body in an embodiment of the utility model;

[0017] Figure 2 This is a schematic diagram of the structure in which a portion of a multi-wafer silicon rod is immersed in silicon liquid in an embodiment of the utility model.

[0018] In the figure:

[0019] 1-Pulling mechanism; 2-Shell; 3-Grabbing mechanism; 4-Multi-wafer silicon rod; 5-Valve; 6-Water-cooled heat shield; 7-Furnace body; 8-Silicon rod; 9-Silicon liquid; 10-Quartz crucible; 11-Crystal rod pulling mechanism. DETAILED DESCRIPTION

[0020] 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.

[0021] refer to Figure 1 The single crystal furnace in the embodiment of the utility model includes a furnace body 7, a quartz crucible 10, a crystal rod pulling mechanism 11, a water-cooled heat shield 6 and a feeding device, wherein the quartz crucible 10 and the water-cooled heat shield 6 are located inside the furnace body 7, and the feeding device is located outside the furnace body 7.

[0022] like Figure 1 As shown, the quartz crucible 10 is filled with silicon liquid 9, and the water-cooled heat shield 6 is located above the quartz crucible 10 and maintains a certain distance from the quartz crucible 10. One end of the crystal rod pulling mechanism 11 can be fixed above the furnace body 7 and extend along the height direction of the furnace body 7 to facilitate pulling the formed crystal rod. During the crystal pulling process, the water-cooled heat shield 6 can be used to absorb the latent heat of crystallization and accelerate the crystallization speed. The length and mass of the formed silicon rod 8 continue to increase, and the silicon liquid 9 in the quartz crucible 10 continues to decrease. Since the height of the water-cooled heat shield 6 remains unchanged, when the silicon liquid in the quartz crucible 10 continues to decrease and cannot be replenished in time, it will affect the crystal pulling efficiency. The feeding device in this embodiment can be used to replenish the silicon liquid 9 in the quartz crucible 10 in real time during the crystal pulling process, thereby ensuring that the liquid level of the silicon liquid 9 in the quartz crucible 10 is constant to ensure the crystal pulling efficiency.

[0023] Specifically, refer to Figure 1 The feeding device includes a pulling mechanism 1, a shell 2, a gripping mechanism 3, a multi-wafer silicon rod 4 and a valve 5. The shell 2 can be installed on the outer wall of the furnace body 7 so that the shell 2 and the furnace body 7 remain relatively fixed during the crystal pulling process. The side wall of the furnace body 7 is provided with a connecting port, which is located above the quartz crucible 10. The bottom of the shell 2 can be connected to the inside of the furnace body 7 through the connecting port. The valve 5 is set at the connecting port. When the valve 5 is opened, the shell 2 and the furnace body 7 are in a connected state. When the valve 5 is closed, the shell 2 and the furnace body 7 are isolated from each other.

[0024] The multi-wafer silicon rod 4 is located inside the housing 2, and the multi-wafer silicon rod 4 extends along the height direction of the furnace body 7, and the multi-wafer silicon rod 4 can move relative to the furnace body 7 along the height direction of the furnace body 7. Figure 2 As shown, when crystal pulling starts, the valve 5 can be opened, the multi-wafer silicon rod 4 can enter the furnace body 7 from the shell 2, and a part of the multi-wafer silicon rod 4 can be immersed in the silicon liquid 9 in the quartz crucible 10. Under the action of high temperature, the multi-wafer silicon rod 4 immersed in the silicon liquid 9 melts, so that the silicon liquid 9 can be replenished to the quartz crucible 10, so that during the crystal pulling process, the liquid level of the silicon liquid 9 in the quartz crucible 10 is guaranteed to remain constant.

[0025] For details, please refer to Figure 1 , the pulling mechanism 1 can be fixed to the top of the housing 2, one end of the grasping mechanism 3 is connected to the pulling mechanism 1, and the other end of the grasping mechanism 3 can be used to clamp the multi-wafer silicon rod 4. When the grasping mechanism 3 clamps the multi-wafer silicon rod 4, the grasping mechanism 3 and the multi-wafer silicon rod 4 remain relatively fixed, and the pulling mechanism 1 can drive the grasping mechanism 3 to move along the height direction of the furnace body 7, thereby realizing the movement of the multi-wafer silicon rod 4. In addition, after the crystal pulling is completed, the pulling mechanism 1 can also pull the grasping mechanism 3 and the remaining multi-wafer silicon rod 4 back into the housing 2 and close the valve 5.

[0026] Since the crystal pulling speed is generally kept constant during the crystal pulling process, that is, the amount of silicon liquid 9 consumed per unit time in the quartz crucible 10 is constant, when a part of the multi-wafer silicon rod 4 is immersed in the silicon liquid 9 in the quartz crucible 10, the multi-wafer silicon rod 4 can be made to descend at a constant speed to ensure that the height of the multi-wafer silicon rod 4 in contact with the silicon liquid 9 is the same per unit time. Since the shape of the multi-wafer silicon rod 4 is regular, the volume of the multi-wafer silicon rod 4 melted in the silicon liquid 9 is determined by the depth of the multi-wafer silicon rod 4 immersed in the silicon liquid 9. At this time, by controlling the descending speed of the multi-wafer silicon rod 4, the depth of the multi-wafer silicon rod 4 immersed in the silicon liquid 9 can be controlled, so that the volume of the multi-wafer silicon rod 4 melted can be matched with the amount of silicon liquid 9 consumed by crystal pulling, so as to realize continuous crystal pulling.

[0027] In order to facilitate the uniform movement of the multi-wafer silicon rod 4, a speed control module can be provided in the lifting mechanism 1, so that when the lifting mechanism 1 drives the grasping mechanism 3 to move, the grasping mechanism 3 moves at a constant speed. Exemplarily, the lifting mechanism 1 can be a driving device based on a lead screw nut, which is driven by a motor to drive the lead screw for transmission, thereby ensuring the uniform speed drive of the lifting mechanism 1.

[0028] In addition, a limiting structure (not shown in the figure) may be provided in the housing 2, and the limiting structure may be used to limit the grasping mechanism 3 to move only in the height direction of the furnace body 7, thereby ensuring that the multi-wafer silicon rod 4 is vertically immersed in the silicon liquid 9, thereby realizing accurate control of the moving speed of the multi-wafer silicon rod 4. The limiting structure may be, for example, a limiting surface provided along the circumference of the inner wall of the housing 2, and the grasping mechanism 3 maintains contact with the limiting surface during movement, thereby realizing movement in the height direction of the furnace body 7.

[0029] It can be understood that by setting the gripping mechanism 3 and the limiting surface, since the outer contour surface of the gripping structure protrudes from the circumferential surface of the multi-wafer silicon rod 4, a certain gap can be maintained between the multi-wafer silicon rod 4 and the limiting surface during the contact between the gripping structure and the limiting surface. While achieving the movement of the multi-wafer silicon rod 4 along the set direction, it can also avoid the loss of the multi-wafer silicon rod 4 or the limiting surface caused by the contact between the multi-wafer silicon rod 4 and the limiting surface.

[0030] In some embodiments, the shell 2 and the furnace body 7 are detachably connected. When the multi-wafer silicon rods 4 in the shell 2 are used up, the shell 2 can be removed from the side wall of the furnace body 7 to facilitate the installation of new multi-wafer silicon rods 4. In addition, the valve 5 and the furnace body 7 can also be fixedly connected. When the shell 2 is separated from the furnace body 7, the valve 5 can be closed to prevent external impurities from entering the interior of the furnace body 7 through the valve 5, thereby affecting the quality of crystal pulling.

[0031] As an optional implementation scheme, the valve 5 may be a gate valve, and the operator may manually open or close the valve 5 for easy operation.

[0032] The feeding device and the single crystal furnace in the embodiment of the utility model are arranged on the outer wall of the furnace body 7, the multi-wafer silicon rod 4 is arranged in the outer shell 2 of the feeding device, and the multi-wafer silicon rod 4 is driven to move up and down by the pulling mechanism 1. At the beginning of crystal pulling, the valve 5 is opened to allow the multi-wafer silicon rod 4 to enter the furnace body 7, and a part of the multi-wafer silicon rod 4 is immersed in the silicon liquid 9 in the quartz crucible 10, and the multi-wafer silicon rod 4 is melted in the silicon liquid 9 to compensate for the consumption of silicon liquid 9 caused by the weight increase and lengthening of the crystal rod. Due to the feeding device and the single crystal furnace in the embodiment of the utility model, feeding can be achieved while pulling crystal, which improves production efficiency and ensures the quality of crystal pulling.

[0033] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A charging device installed in a furnace body of a single crystal furnace, wherein the single crystal furnace comprises a quartz crucible arranged in the furnace body, and the quartz crucible is used to fill silicon liquid, characterized in that: The feeding device comprises a housing, a multi-wafer silicon rod and a valve; The shell is mounted on the outer wall of the furnace body, a communication port is provided on the side wall of the furnace body, the bottom of the shell is communicated with the interior of the furnace body through the communication port, and the valve is provided at the communication port to open or close the communication port; The poly-wafer silicon rod is arranged inside the shell, and the poly-wafer silicon rod extends along the height direction of the furnace body. The poly-wafer silicon rod can move relative to the furnace body along the height direction of the furnace body so that a part of the poly-wafer silicon rod is immersed in the silicon liquid.

2. The feeding device according to claim 1, characterized in that It also includes a lifting mechanism fixed in the shell, and the lifting mechanism is used to drive the multi-wafer silicon rod to extend along the height direction of the furnace body.

3. The feeding device according to claim 2, characterized in that The lifting mechanism has a speed control module, and the speed control module is used to make the multi-wafer silicon rod move at a uniform speed relative to the furnace body.

4. The feeding device according to claim 2, characterized in that It also includes a grasping mechanism, one end of which is connected to the lifting mechanism, and the other end of which is used to clamp the multi-wafer silicon rod.

5. The feeding device according to claim 4, characterized in that A limiting structure is provided inside the shell, and the limiting structure is used to limit the movement of the grabbing mechanism along the height direction of the furnace body.

6. The feeding device according to claim 1, characterized in that The valve is a gate valve.

7. A single crystal furnace, characterized in that: It comprises a furnace body, a crystal rod pulling mechanism, a quartz crucible and a feeding device as claimed in any one of claims 1 to 6, wherein the crystal rod pulling mechanism and the quartz crucible are both arranged inside the furnace body, and the feeding device is installed on the outer wall of the furnace body.

8. The single crystal furnace according to claim 7, characterized in that: The shell and the furnace body are detachably connected.

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