Ingot furnace vacuumizing system and control method for ingot furnace vacuumizing system

Abstract

The ingot furnace vacuumizing system comprises a first pump body, an exhaust pipe set and a control valve set, the exhaust pipe set comprises a plurality of exhaust pipes, the exhaust pipes are connected between the first pump body and an ingot furnace in parallel, the control valve set comprises a plurality of control valves, and the control valves are connected between the first pump body and the ingot furnace in parallel. The multiple control valves are arranged on the multiple exhaust pipes in a one-to-one correspondence mode, and the multiple control valves are used for controlling the different exhaust pipes to be opened or closed when the ingot casting furnace is in different ingot casting operation stages so as to control the pressure value in the ingot casting furnace. According to the ingot furnace vacuumizing system, the exhaust pipe set and the control valve body are arranged, so that the control valve set can automatically or manually control opening or closing of different exhaust pipes according to the preset pressure value, and the purpose of adjusting the pressure in the ingot furnace is achieved, for example, the constant low-pressure state in the heating stage needs to be met in the silicon powder purification process; the content of boron can be effectively reduced, so that the purity of silicon crystals and the environment of a thermal field are improved.

Description

Technical Field

[0001] The present invention relates to the field of polysilicon production, and in particular to a vacuum pumping system for an ingot furnace and a control method therefor. Background Art

[0002] Silicon wafers are the carriers of solar cells. The quality of silicon wafers directly determines the conversion efficiency of solar cells. Silicon wafers are cut from crystalline silicon ingots. The quality of crystalline silicon ingots directly determines the quality of the prepared silicon wafers. Therefore, in order to make solar cells have a higher conversion efficiency, it is necessary to first ensure the quality of the crystalline silicon ingots.

[0003] The entire production process of crystalline silicon ingots takes more than 70 hours, and during the production process, in order to ensure the quality of silicon ingots, there are specific requirements for the gas pressure in the ingot casting furnace and the ambient gas at each production stage. In particular, the silicon powder purification process, which needs to be explained is different from the traditional multi-crystalline silicon wafer process. The silicon powder purification product is used as the raw material for the single crystal pulling end, and has higher requirements for purity and boron content. In particular, the heating and melting stage needs to be in a constant low-pressure state, otherwise it is easy for the boron content in the crucible to fail to meet the requirements, which will directly affect the purity of the silicon ingot. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to provide an ingot furnace vacuum system, which can more accurately control the pressure value in the ingot furnace, provide a constant low-pressure environment, meet the constant low-pressure state required in the heating stage of the silicon powder purification process, and effectively improve the purity of silicon ingots.

[0005] According to the vacuum pumping system for an ingot furnace of an embodiment of the present invention, the vacuum pumping system for the ingot furnace includes a first pump body, an exhaust pipe group and a control valve group, the exhaust pipe group includes a plurality of exhaust pipes, and the plurality of exhaust pipes are connected in parallel between the first pump body and the ingot furnace, the control valve group includes a plurality of control valves, and the plurality of control valves are arranged on the plurality of exhaust pipes in a one-to-one correspondence, and the plurality of control valves are used to control different exhaust pipes to open or close when the ingot furnace is in different ingot casting operation stages to control the pressure value in the ingot casting furnace, wherein the ingot casting operation stages include exhaust pipe stage, heating stage and crystal growth stage.

[0006] According to the vacuum pumping system of the ingot furnace of the embodiment of the present invention, by setting an exhaust pipe group and a control valve body, the pressure value in the ingot furnace can be accurately controlled according to different working stages. For example, the silicon powder purification process needs to meet the constant low-pressure state in the heating stage. Therefore, the control method of the vacuum pumping system of the ingot furnace of the present invention can ensure the stability and reliability of the ingot casting process, and can effectively reduce the boron content, thereby improving the purity of the silicon crystal and the thermal field environment, and improving the working efficiency and maintenance cost of the ingot furnace.

[0007] In addition, the vacuum pumping system for the ingot casting furnace according to the present invention may also have the following additional technical features:

[0008] In some embodiments of the present invention, the exhaust pipe group includes: a first exhaust pipe, a second exhaust pipe and a third exhaust pipe, the first exhaust pipe, the second exhaust pipe and the third exhaust pipe are all connected in parallel between the first pump body and the ingot furnace, the control valve group includes a first control valve, a second control valve and a third control valve, the first control valve is arranged on the first exhaust pipe, the second control valve is arranged on the second exhaust pipe, and the third control valve is arranged on the third exhaust pipe.

[0009] In some embodiments of the present invention, the diameter of the third air extraction pipe is greater than the diameter of the first air extraction pipe, and the diameter of the third air extraction pipe is greater than the diameter of the second air extraction pipe.

[0010] In some embodiments of the present invention, the vacuum system of the ingot casting furnace also includes a second pump body, which is connected in series between the first pump body and the exhaust pipe group, and the second pump body is connected in series with the first pump body through a connecting pipe, wherein the air inlet end of the first exhaust pipe, the air inlet end of the second exhaust pipe and the air inlet end of the third exhaust pipe are all connected to the ingot casting furnace, and the air outlet end of the first exhaust pipe, the air outlet end of the second exhaust pipe and the air outlet end of the third exhaust pipe are all connected to the second pump body.

[0011] In some embodiments of the present invention, the vacuum pumping system of the ingot casting furnace further includes a fourth tube body, an air inlet end of the fourth tube body is connected to the ingot casting furnace, and an air outlet end of the fourth tube body is connected to the connecting pipe.

[0012] In some embodiments of the present invention, the vacuum system of the ingot casting furnace also includes a second pump body, which is connected in series between the first pump body and the exhaust pipe group, and the second pump body is connected in series with the first pump body through a connecting pipe, wherein the air inlet end of the first exhaust pipe, the air inlet end of the second exhaust pipe and the air inlet end of the third exhaust pipe are all connected to the ingot casting furnace, the air outlet end of the first exhaust pipe and the air outlet end of the second exhaust pipe are both connected to the second pump body, and the air outlet end of the third exhaust pipe is connected to the connecting pipe.

[0013] The invention also provides a control method for the vacuum pumping system of the ingot casting furnace.

[0014] In some embodiments of the present invention, a control method for a vacuum pumping system of an ingot casting furnace includes starting a first pump body and obtaining the ingot casting operation stage of the ingot casting furnace, and controlling corresponding control valves on different exhaust pipes to open or close according to different ingot casting operation stages to control the pressure value in the ingot casting furnace, wherein the ingot casting operation stage includes an exhaust stage, a heating stage and a crystal growth stage.

[0015] According to the control method of the vacuum pumping system of the ingot furnace of the embodiment of the present invention, the number of vacuum pipes opened or closed can be flexibly controlled according to the actual working conditions of the ingot furnace, and the pressure value in the ingot furnace can be accurately controlled according to different working stages. For example, the silicon powder purification process needs to meet the constant low-pressure state in the heating stage. Therefore, the control method of the vacuum pumping system of the ingot furnace of the present invention can ensure the stability and reliability of the ingot casting process, can effectively reduce the boron content, and thereby improve the purity of the silicon crystal and the thermal environment, thereby improving the working efficiency and maintenance cost of the ingot furnace.

[0016] In some embodiments of the present invention, when the ingot casting operation stage is the exhaust stage, a first predetermined number of control valves are opened to allow the pressure value in the ingot casting furnace to drop to a first threshold value; when the pressure value in the ingot casting furnace drops to the first threshold value, a second predetermined number of control valves are opened to allow the pressure value in the ingot casting furnace to drop from the first threshold value to the second threshold value.

[0017] In some embodiments of the present invention, when the ingot casting operation stage is a heating stage, the openings of the second predetermined number of control valves are controlled so that the pressure value in the ingot casting furnace is maintained at a second threshold value.

[0018] In some embodiments of the present invention, when the ingot casting operation stage is the crystal growth stage, the second predetermined number of control valves are closed so that the pressure value in the ingot casting furnace rises from the second threshold value to a third threshold value, wherein the third threshold value is greater than the first threshold value.

[0019] In some embodiments of the present invention, when the ingot casting operation stage is the exhaust stage and the pressure value in the ingot casting furnace drops from the first threshold value to the second threshold value, the second pump body is opened so that the pressure value in the ingot casting furnace drops from the second threshold value to the fourth threshold value.

[0020] In some embodiments of the present invention, when the ingot casting operation stage is the crystal growth stage, the second pump body and the second predetermined number of control valves are closed so that the pressure value in the ingot casting furnace rises from the fourth threshold value to the third threshold value, wherein the third threshold value is greater than the first threshold value.

[0021] In some embodiments of the present invention, starting the first pump body includes determining whether argon is filled into the ingot casting furnace, and starting the first pump body when argon is filled into the ingot casting furnace.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0024] Figure 1 It is a schematic structural diagram of a vacuum pumping system for an ingot casting furnace according to a first embodiment of the present invention.

[0025] Figure 2 It is a working flow chart of the vacuum pumping system of the ingot furnace according to the first embodiment of the present invention.

[0026] Figure 3 It is a schematic structural diagram of a vacuum pumping system for an ingot casting furnace according to a second embodiment of the present invention.

[0027] Figure 4 It is a working flow chart of the vacuum pumping system of the ingot furnace according to the second embodiment of the present invention.

[0028] Figure 5 It is a schematic structural diagram of a vacuum pumping system for an ingot casting furnace according to a third embodiment of the present invention.

[0029] Figure 6 It is a working flow chart of the vacuum pumping system of the ingot furnace according to the third embodiment of the present invention.

[0030] Figure 7 It is a schematic structural diagram of a vacuum pumping system for an ingot casting furnace according to a fourth embodiment of the present invention.

[0031] Figure 8 It is a working flow chart of the vacuum pumping system of the ingot furnace according to the fourth embodiment of the present invention.

[0032] Fig. 9 It is a schematic structural diagram of a vacuum pumping system for an ingot furnace according to a fifth embodiment of the present invention.

[0033] Fig.10 It is a working flow chart of the vacuum pumping system of the ingot furnace according to the fifth embodiment of the present invention.

[0034] Reference numerals:

[0035] First pump body 1, second pump body 2, first air extraction pipe 3, second air extraction pipe 4, third air extraction pipe 5, fourth air extraction pipe 6, first control valve 7, second control valve 8, third control valve 9, fourth control valve 10, connecting pipe 11,

[0036] Ingot casting furnace 20. DETAILED DESCRIPTION

[0037] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0038] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] Reference below Figure 1-Figure 10 A vacuum pumping system for an ingot casting furnace according to an embodiment of the present invention is described.

[0041] refer to Figure 1-Figure 10As shown, the vacuum pumping system of the ingot furnace is used to vacuum the ingot furnace 20 so that the pressure in the ingot furnace 20 reaches a preset pressure value. The vacuum pumping system of the ingot furnace includes a first pump body 1, an exhaust pipe group and a control valve group. The first pump body 1 can provide power for exhaust work. The exhaust pipe group includes a plurality of exhaust pipes. The plurality of exhaust pipes are connected in parallel between the first pump body 1 and the ingot furnace 20 so that the first pump body 1 can exhaust the gas in the ingot furnace 20 through the exhaust pipe group. The control valve group includes a plurality of control valves. The plurality of control valves are arranged on the plurality of exhaust pipes in a one-to-one correspondence. , multiple control valves are used to control different exhaust pipes to open or close when the ingot casting furnace 20 is in different ingot casting operation stages to control the pressure value in the ingot casting furnace 20, wherein the ingot casting operation stage includes an exhaust stage, a heating stage and a crystal growth stage. During the exhaust stage, the ingot casting furnace 20 is evacuated to make the ingot casting furnace 20 reach a preset pressure value to create a good processing environment for the silicon material. During the heating stage, the ingot casting furnace 20 heats the silicon material to melt it. During the crystal growth stage, the crystal grows upward from the bottom of the crucible to generate silicon crystals.

[0042] Continue to refer Figure 1-Figure 10 As shown, different stages of the ingot casting operation have different requirements for the pressure inside the ingot casting furnace 20. When the ingot casting furnace 20 is in different stages of the ingot casting operation, the control valve group can automatically or manually control the opening or closing of different exhaust pipes according to the preset pressure value to achieve the purpose of adjusting the pressure inside the ingot casting furnace 20, thereby realizing the smooth switching of these working stages. The number and position of the exhaust pipes can be flexibly adjusted according to the actual working conditions of the ingot casting furnace 20 to improve the exhaust efficiency and uniformity. The pressure value inside the ingot casting furnace 20 can be accurately controlled according to different working stages to ensure the stability and reliability of the ingot casting process. During the exhaust process, the oxides and dust in the ingot casting furnace 20 are sucked out to improve the purity of the silicon crystal and the thermal environment, thereby improving the working efficiency and maintenance cost of the ingot casting furnace 20.

[0043] Taking the silicon powder purification process as an example, the silicon powder purification product is used as the raw material for the single crystal pulling end, and has higher requirements on purity and boron content. The heating stage needs to be in a constant low-pressure state, which is beneficial to reduce the boron content and impurity concentration, thereby achieving the purpose of improving the purity of the silicon ingot. Therefore, according to the vacuum pumping system of the ingot furnace of the present invention, by controlling different exhaust pipes to open or close, it can better meet the constant low-pressure state in the heating stage, thereby better improving the purity of the silicon ingot.

[0044] Compared with the traditional vacuum system used in ingot casting furnaces, it is often only suitable for multi-crystalline silicon wafer processes. It does not need to make the pressure value in the crucible maintain a constant low pressure state required to meet the heating stage in the silicon powder purification process, and it often does not have the ability to provide the constant low pressure state required to meet the heating stage in the silicon powder purification process. Therefore, the purity of silicon ingots obtained in the traditional silicon powder purification process is not ideal. The vacuum pumping system of the ingot furnace of the present application is provided with an exhaust pipe group and a control valve body, so that when the ingot furnace 20 is in different ingot casting operation stages, the control valve group can automatically or manually control the opening or closing of different exhaust pipes according to a preset pressure value, so as to achieve the purpose of adjusting the pressure in the ingot casting furnace 20, thereby realizing the smooth switching of these working stages, and can flexibly adjust the number of exhaust pipes opened according to the actual working conditions of the ingot casting furnace 20, and can accurately control the pressure value in the ingot casting furnace 20 according to different working stages. For example, the constant low-pressure state in the heating stage needs to be satisfied in the silicon powder purification process. Therefore, the vacuum pumping system of the ingot furnace of the present invention can ensure the stability and reliability of the ingot casting process, can effectively reduce the boron content, and thereby improve the purity of the silicon crystal and the thermal environment, thereby improving the working efficiency and maintenance cost of the ingot casting furnace 20.

[0045] Therefore, according to the vacuum pumping system of the ingot furnace of the embodiment of the present invention, by setting the exhaust pipe group and the control valve body, when the ingot furnace 20 is in different ingot casting operation stages, the control valve group can automatically or manually control the opening or closing of different exhaust pipes according to the preset pressure value, so as to achieve the purpose of adjusting the pressure in the ingot casting furnace 20, thereby realizing the smooth switching of these working stages. According to the actual working conditions of the ingot casting furnace 20, the number of exhaust pipes opened or closed can be flexibly controlled to improve the exhaust efficiency and uniformity. According to different working stages, especially the heating stage in the silicon powder purification process, the pressure value in the ingot casting furnace 20 can be controlled more accurately to ensure the stability and reliability of the ingot casting process, and the boron content can be effectively reduced, thereby improving the purity of the silicon crystal and the thermal environment, thereby improving the working efficiency of the ingot casting furnace 20.

[0046] In some embodiments of the present invention, reference Figure 1-Figure 10As shown, the exhaust pipe group includes a first exhaust pipe 3, a second exhaust pipe 4 and a third exhaust pipe 5, which are all connected in parallel between the first pump body 1 and the ingot casting furnace 20. The control valve group includes a first control valve 7, a second control valve 8 and a third control valve 9. The first control valve 7 is arranged on the first exhaust pipe 3, the second control valve 8 is arranged on the second exhaust pipe 4, and the third control valve 9 is arranged on the third exhaust pipe 5. A pressure detection device can be arranged in the ingot casting furnace 20 to obtain the pressure value in the furnace in time, and the switch state or opening and closing of each exhaust pipe can be flexibly adjusted according to the pressure value in the ingot casting furnace 20. To achieve different exhaust effects, if it is necessary to reduce the pressure in the ingot casting furnace 20, the first control valve 7, the second control valve 8 and the third control valve 9 can be opened. Alternatively, the pressure in the ingot casting furnace 20 can be increased by closing one or more of the first control valve 7, the second control valve 8 or the third control valve 9 to adapt to the pressure requirements of different stages of the ingot casting operation. At the same time, if the first exhaust pipe 3, the second exhaust pipe 4 or the third exhaust pipe 5 fails or is blocked, the corresponding control valve can be closed in time to avoid the normal operation of the vacuum system of the ingot casting furnace and improve the efficiency and safety of the vacuum system of the ingot casting furnace.

[0047] In some embodiments of the present invention, reference Figure 1-Figure 10 As shown, the diameter of the third exhaust pipe 5 is larger than that of the first exhaust pipe 3, and the diameter of the third exhaust pipe 5 is larger than that of the second exhaust pipe 4. According to different exhaust requirements, a suitable exhaust pipe combination can be selected to achieve different exhaust speeds and pressures. The third exhaust pipe 5 has a larger diameter, which can improve the exhaust efficiency. When the pressure in the ingot casting furnace 20 needs to be quickly reduced to a reduced pressure value, the exhaust efficiency is improved. By utilizing the small diameters of the first exhaust pipe 3 and the second exhaust pipe 4, when the pressure in the ingot casting furnace 20 needs to be slowly adjusted, the pressure value in the ingot casting furnace 20 can be more accurately increased or decreased, thereby increasing the flexibility and adaptability of the vacuum system of the ingot casting furnace, thereby meeting different ingot casting working conditions.

[0048] In some embodiments of the present invention, reference Figure 1-Figure 10As shown, the vacuum pumping system of the ingot furnace also includes a second pump body 2, which is connected in series between the first pump body 1 and the exhaust pipe group, and the second pump body 2 is connected in series with the first pump body 1 through a connecting pipe 11, wherein the air inlet end of the first exhaust pipe 3, the air inlet end of the second exhaust pipe 4 and the air inlet end of the third exhaust pipe 5 are all connected to the ingot furnace 20, and the air outlet end of the first exhaust pipe 3, the air outlet end of the second exhaust pipe 4 and the air outlet end of the third exhaust pipe 5 are all connected to the second pump body 2. The series connection of the first pump body 1 and the second pump body 2 can be used to achieve high-efficiency and high-stability exhaust work of the vacuum pumping system of the ingot furnace, and the vacuum pumping system of the ingot furnace can be used to achieve high-efficiency and high-stability exhaust work. The first pump body 1 and the second pump body 2 are separately arranged by using a connecting pipe 11, so that the first pump body 1 and the second pump body 2 can be maintained and controlled separately, thereby increasing the flexibility and adaptability of the vacuum pumping system of the ingot casting furnace and meeting the requirements of different ingot casting working environments. In a specific embodiment, the second pump body 2 can be a Roots pump that can be used in conjunction with a fore-stage pump such as a mechanical pump to meet the requirement of a high pumping speed at a specific pressure value, and an overflow valve or a steam condenser can be provided to protect the safe and stable operation of the pump to prevent it from being overloaded and causing safety hazards, thereby improving the operating stability of the vacuum pumping system of the ingot casting furnace.

[0049] The invention also provides a control method for the vacuum pumping system of the ingot casting furnace.

[0050] In some embodiments of the present invention, the control method of the vacuum system of the ingot casting furnace includes starting the first pump body 1 and obtaining the ingot casting operation stage of the ingot casting furnace 20, and controlling the corresponding control valves on different exhaust pipes to open or close according to different ingot casting operation stages to control the pressure value in the ingot casting furnace 20, wherein the ingot casting operation stage includes the exhaust stage, the heating stage and the crystal growth stage.

[0051] According to the control method of the vacuum pumping system of the ingot furnace of the embodiment of the present invention, the number of vacuum pipes opened or closed can be flexibly controlled according to the actual working conditions of the ingot furnace 20, and the pressure value in the ingot furnace 20 can be accurately controlled according to different working stages. For example, the silicon powder purification process needs to meet the constant low-pressure state in the heating stage. Therefore, the vacuum pumping system of the ingot furnace of the present invention can ensure the stability and reliability of the ingot casting process, can effectively reduce the boron content, and thereby improve the purity of the silicon crystal and the thermal field environment, thereby improving the working efficiency and maintenance cost of the ingot furnace 20.

[0052] In some embodiments of the present invention, when the ingot casting operation stage is the exhaust stage, a first predetermined number of control valves are opened to allow the pressure value in the ingot casting furnace 20 to drop to a first threshold value; when the pressure value in the ingot casting furnace 20 drops to the first threshold value, a second predetermined number of control valves are opened to allow the pressure value in the ingot casting furnace 20 to drop from the first threshold value to the second threshold value.

[0053] In some embodiments of the present invention, when the ingot casting operation stage is the heating stage, the openings of the second predetermined number of control valves are controlled to keep the pressure value in the ingot casting furnace 20 at the second threshold value.

[0054] In some embodiments of the present invention, when the ingot casting operation stage is the crystal growth stage, a second predetermined number of control valves are closed so that the pressure value in the ingot casting furnace 20 rises from the second threshold to the third threshold, wherein the third threshold is greater than the first threshold.

[0055] In some embodiments of the present invention, when the ingot casting operation stage is the exhaust stage and the pressure value in the ingot casting furnace 20 drops from the first threshold value to the second threshold value, the second pump body 2 is opened to make the pressure value in the ingot casting furnace 20 drop from the second threshold value to the fourth threshold value.

[0056] In some embodiments of the present invention, when the ingot casting operation stage is the crystal growth stage, the second pump body 2 and the second predetermined number of control valves are closed so that the pressure value in the ingot casting furnace 20 rises from the fourth threshold value to the third threshold value, wherein the third threshold value is greater than the first threshold value.

[0057] In some embodiments of the present invention, starting the first pump body 1 includes determining whether argon is filled into the ingot casting furnace 20 , and starting the first pump body 1 when argon is filled into the ingot casting furnace 20 .

[0058] Reference below Figure 1-Figure 10 The control method of the vacuum system of the ingot furnace in the silicon powder purification process of the five embodiments of the present application is described. In addition, in the following five embodiments, the crucible can be kept in a constant low-pressure state during the heating stage, thereby effectively reducing the boron content and effectively improving the purity of the silicon ingot.

[0059] refer to Figure 1-Figure 2As shown, in the first embodiment, the vacuum system of the ingot furnace has a first pump body 1, a first exhaust pipe 3, a second exhaust pipe 4, a third exhaust pipe 5, a first control valve 7, a second control valve 8 and a third control valve 9. In the exhaust stage, the first pump body 1 is opened, and the first control valve 7 and the second control valve 8 are opened at the same time, so that the first exhaust pipe 3 and the second exhaust pipe 4 are in a connected state, so that the gas in the ingot furnace 20 is conveniently extracted through the first exhaust pipe 3 and the second exhaust pipe 4, and then argon gas is filled into the ingot furnace 20 to create a good processing environment for the silicon material. When the pressure value in the ingot furnace 20 drops to the first threshold value, the third control valve 9 is opened to connect the third exhaust pipe 5, so that the pressure value in the ingot furnace 20 drops to the second threshold value, and the heating function of the ingot furnace 20 is turned on. At this time, the ingot casting operation is in the heating stage. At this stage, the opening of one or more control valves among the first control valve 7, the second control valve 8 or the third control valve 9 can be controlled to keep the pressure value in the ingot furnace 20 at the second threshold value. To facilitate the stable operation of the ingot casting furnace 20 during the heating stage, after the work in the heating stage is completed, the second control valve 8 and the third control valve 9 are closed, and the opening of the first control valve 7 is adjusted so that the pressure in the ingot casting furnace 20 rises to the third threshold value, creating a good working environment for the crystal growth stage. In this embodiment, starting from the vacuum stage, a stable flow of argon and other protective gases can be continuously introduced to better ensure the effect of reducing boron and removing impurities to ensure the purity of the silicon ingot, and to obtain a lower pressure during the ingot casting process, thereby improving the purity and quality of the silicon crystal. At the same time, the pressure in the furnace can be controlled up and down by the control valve, which has strong flexibility and improves the efficiency of ingot casting. It should be noted that the first threshold value is greater than the second threshold value, and the third threshold value is greater than the first threshold value. The first threshold value can be between 200mbar-300mbar, the second threshold value can be between 30mbar-100mbar, and the third threshold value can be between 300mbar-600mbar, which can be adjusted according to specific circumstances.

[0060] refer to Figure 3-Figure 4As shown, in the second embodiment, the vacuum system of the ingot furnace comprises a first pump body 1, a first exhaust pipe 3, a second exhaust pipe 4, a third exhaust pipe 5, a first control valve 7, a second control valve 8 and a third control valve 9, wherein the air inlet end of the third exhaust pipe 5 is connected to the ingot furnace 20, and the third control valve 9 controls the opening or closing of the third exhaust pipe 5. In the exhaust stage, the first pump body 1 is opened, and the first control valve 7 and the second control valve 8 are opened at the same time, so that the first exhaust pipe 3 and the second exhaust pipe 4 are in a connected state, so that the gas in the ingot furnace 20 passes through the first exhaust pipe 3. The exhaust pipe 3 and the second exhaust pipe 4 are extracted, and then argon gas is filled into the ingot casting furnace 20 to create a good processing environment for the silicon material. When the pressure value in the ingot casting furnace 20 drops to the first threshold, the third control valve 9 is opened to connect the third exhaust pipe 5, so that the pressure value in the ingot casting furnace 20 drops to the second threshold, and the heating function of the ingot casting furnace 20 is turned on. At this time, the ingot casting operation is in the heating stage. At this stage, the opening of one or more control valves among the first control valve 7, the second control valve 8 or the third control valve 9 can be controlled to make the ingot casting furnace 20 The pressure value inside is maintained at the second threshold value, which is convenient for the stable operation of the ingot casting furnace 20 during the heating stage. When the work in the heating stage is completed, the second control valve 8 and the third control valve 9 are closed, and the opening of the first control valve 7 is adjusted so that the pressure inside the ingot casting furnace 20 rises to the third threshold value, creating a good working environment for the crystal growth stage. In this embodiment, starting from the exhaust stage, a stable flow of argon and other protective gases can be continuously introduced to better ensure the effect of reducing boron and removing impurities to ensure the purity of the silicon ingot, and a lower pressure can be obtained during the ingot casting process, thereby improving the purity and quality of the silicon crystal. At the same time, the pressure in the furnace can be controlled up and down by the control valve, which has strong flexibility and improves the working efficiency of the ingot casting. It should be noted that the third control valve 9 is always in a closed state, and the first threshold value is greater than the second threshold value, and the third threshold value is greater than the first threshold value. The first threshold value can be between 200mbar-300mbar, the second threshold value can be between 30mbar-100mbar, and the third threshold value can be between 300mbar-600mbar, which can be adjusted according to specific circumstances.

[0061] refer to Figure 5-Figure 6As shown, in the third embodiment, the vacuum system of the ingot furnace comprises a first pump body 1, a second pump body 2, a first exhaust pipe 3, a second exhaust pipe 4, a third exhaust pipe 5, a first control valve 7, a second control valve 8 and a third control valve 9. In the exhaust stage, the first pump body 1 is opened, and the first control valve 7 and the second control valve 8 are opened at the same time, so that the first exhaust pipe 3 and the second exhaust pipe 4 are in a connected state, so that the gas in the ingot furnace 20 is extracted through the first exhaust pipe 3 and the second exhaust pipe 4, and then argon gas is filled into the ingot furnace 20 so that To create a good processing environment for silicon materials, when the pressure value in the ingot casting furnace 20 drops to the first threshold value, the third control valve 9 is opened to connect the third exhaust pipe 5, so that the pressure value in the ingot casting furnace 20 is lower than 100mbar, the second pump body 2 is opened, and the heating function of the ingot casting furnace 20 is turned on. At this time, the ingot casting operation is in the heating stage. At this stage, the opening of one or more control valves among the first control valve 7, the second control valve 8 or the third control valve 9 can be controlled to keep the pressure value in the ingot casting furnace 20 at the fourth threshold value, which is convenient for ingot casting. The furnace 20 operates stably in the heating stage. When the work in the heating stage is completed, the second control valve 8, the third control valve 9 and the second pump body 2 are closed, and the opening of the first control valve 7 is adjusted so that the pressure in the ingot furnace 20 rises to the third threshold value, creating a good working environment for the crystal growth stage. In this embodiment, starting from the exhaust stage, a stable flow of argon and other protective gases can be continuously introduced to better ensure the effect of reducing boron and removing impurities to ensure the purity of the silicon ingot, and to obtain a lower pressure during the ingot casting process, thereby improving the purity and quality of the silicon crystal. At the same time, the pressure in the furnace can be controlled up and down by the control valve, which has strong flexibility and improves the efficiency of ingot casting. It should be noted that the first threshold value is greater than the second threshold value, and the third threshold value is greater than the first threshold value. The first threshold value can be between 200mbar-300mbar, the second threshold value can be between 30mbar-100mbar, the third threshold value can be between 300mbar-600mbar, and the fourth threshold value can be between 3mbar-30mbar, which can be adjusted according to specific circumstances.

[0062] refer to Figure 7-Figure 8As shown, in the fourth embodiment, the vacuum system of the ingot casting furnace comprises a first pump body 1, a second pump body 2, a first exhaust pipe 3, a second exhaust pipe 4, a third exhaust pipe 5, a first control valve 7, a second control valve 8 and a third control valve 9. In the exhaust stage, the first pump body 1 is opened, and the first control valve 7 and the second control valve 8 are opened at the same time, so that the first exhaust pipe 3 and the second exhaust pipe 4 are in a connected state, so that the gas in the ingot casting furnace 20 is extracted through the first exhaust pipe 3 and the second exhaust pipe 4, and then the ingot casting furnace 20 is filled with argon gas to provide a silicon material camp. To create a good processing environment, when the pressure value in the ingot casting furnace 20 drops to the first threshold value, the third control valve 9 is opened to connect the third exhaust pipe 5, so that the pressure value in the ingot casting furnace 20 is lower than 100mbar, the second pump body 2 is opened, and the heating function of the ingot casting furnace 20 is turned on. At this time, the ingot casting operation is in the heating stage. In this stage, the opening of one or more control valves of the first control valve 7, the second control valve 8 or the third control valve 9 can be controlled to keep the pressure value in the ingot casting furnace 20 at the fourth threshold value, so that the ingot casting furnace 20 is in the heating stage. Stable operation. When the work in the heating stage is completed, close the second control valve 8, the third control valve 9 and the second pump body 2, and adjust the opening of the first control valve 7 so that the pressure in the ingot furnace 20 rises to the third threshold value to create a good working environment for the crystal growth stage. In this embodiment, starting from the exhaust stage, a stable flow of argon and other protective gases can be continuously introduced to better ensure the effect of reducing boron and removing impurities to ensure the purity of the silicon ingot, and to obtain a lower pressure during the ingot casting process, thereby improving the purity and quality of the silicon crystal. At the same time, the pressure in the furnace can be controlled up and down by the control valve, which has strong flexibility and improves the efficiency of ingot casting. It should be noted that the third control valve 9 is always in a closed state, the first threshold value is greater than the second threshold value, the third threshold value is greater than the first threshold value, the first threshold value can be between 200mbar-300mbar, the second threshold value can be between 30mbar-100mbar, the third threshold value can be between 300mbar-600mbar, and the fourth threshold value can be between 3mbar-30mbar, which can be adjusted according to specific circumstances.

[0063] refer to Figure 9-10As shown, in the fifth embodiment, the vacuum system of the ingot furnace comprises a first pump body 1, a second pump body 2, a first exhaust pipe 3, a second exhaust pipe 4, a third exhaust pipe 5, a fourth exhaust pipe 6, a first control valve 7, a second control valve 8, a third control valve 9 and a fourth control valve 10. In the exhaust stage, the first pump body 1 is opened, and the first control valve 7 and the second control valve 8 are opened at the same time, so that the first exhaust pipe 3 and the second exhaust pipe 4 are in a connected state, so that the gas in the ingot furnace 20 is extracted through the first exhaust pipe 3 and the second exhaust pipe 4, and then the ingot furnace 20 is filled with argon. , in order to create a good processing environment for silicon materials, when the pressure value in the ingot casting furnace 20 drops to the first threshold value, the third control valve 9 and the fourth control valve 10 are opened to connect the third exhaust pipe 5 and the fourth exhaust pipe 6, so that the pressure value in the ingot casting furnace 20 is lower than 100mbar, the second pump body 2 is opened, and the heating function of the ingot casting furnace 20 is turned on. At this time, the ingot casting operation is in the heating stage. At this stage, the opening of one or more control valves of the first control valve 7, the second control valve 8, the third control valve 9 or the fourth control valve 10 can be controlled to make the pressure in the ingot casting furnace 20 The pressure value is maintained at the fourth threshold value, which is convenient for the stable operation of the ingot casting furnace 20 in the heating stage. When the work in the heating stage is completed, the second control valve 8, the third control valve 9, the fourth control valve 10 and the second pump body 2 are closed, and the opening of the first control valve 7 is adjusted so that the pressure in the ingot casting furnace 20 rises to the third threshold value, creating a good working environment for the crystal growth stage. In this embodiment, starting from the exhaust stage, a stable flow of argon and other protective gases can be continuously introduced to better ensure the effect of reducing boron and removing impurities to ensure the purity of the silicon ingot, and to obtain a lower pressure during the ingot casting process, thereby improving the purity and quality of the silicon crystal. At the same time, the pressure in the furnace can be controlled up and down by the control valve, which has strong flexibility and improves the efficiency of ingot casting. It should be noted that the first threshold value is greater than the second threshold value, and the third threshold value is greater than the first threshold value. The first threshold value can be between 200mbar-300mbar, the second threshold value can be between 30mbar-100mbar, the third threshold value can be between 300mbar-600mbar, and the fourth threshold value can be between 3mbar-30mbar, which can be adjusted according to specific circumstances.

[0064] Other structures and operations of the vacuum pumping system of the ingot furnace according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0065] In the description of this specification, the description with reference to the terms "some embodiments", "optionally", "further" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0066] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A vacuum system for an ingot casting furnace, characterized in that: include: A first pump body (1); An exhaust pipe group, the exhaust pipe group comprising a plurality of exhaust pipes, the plurality of exhaust pipes being connected in parallel between the first pump body (1) and the ingot casting furnace (20); A control valve group, wherein the control valve group includes a plurality of control valves, and the plurality of control valves are arranged one by one on the plurality of exhaust pipes, and the plurality of control valves are used to control the opening or closing of different exhaust pipes when the ingot casting furnace (20) is in different ingot casting operation stages, so as to control the pressure value in the ingot casting furnace (20), wherein the ingot casting operation stages include: exhaust stage, heating stage and crystal growth stage.

2. The vacuum system for an ingot casting furnace according to claim 1, characterized in that: The exhaust pipe group comprises: a first exhaust pipe (3), a second exhaust pipe (4) and a third exhaust pipe (5); the first exhaust pipe (3), the second exhaust pipe (4) and the third exhaust pipe (5) are all connected in parallel between the first pump body (1) and the ingot casting furnace (20); The control valve group comprises a first control valve (7), a second control valve (8) and a third control valve (9); the first control valve (7) is arranged on the first air extraction pipe (3), the second control valve (8) is arranged on the second air extraction pipe (4), and the third control valve (9) is arranged on the third air extraction pipe (5).

3. The vacuum system for an ingot casting furnace according to claim 2, characterized in that: The diameter of the third air extraction pipe (5) is greater than the diameter of the first air extraction pipe (3), and the diameter of the third air extraction pipe (5) is greater than the diameter of the second air extraction pipe (4).

4. The vacuum system for an ingot casting furnace according to claim 2 or 3, characterized in that: It also comprises a second pump body (2), wherein the second pump body (2) is connected in series between the first pump body (1) and the air extraction pipe group, and the second pump body (2) and the first pump body (1) are connected in series via a connecting pipe (11), wherein: The air inlet end of the first air exhaust pipe (3), the air inlet end of the second air exhaust pipe (4) and the air inlet end of the third air exhaust pipe (5) are all connected to the ingot casting furnace (20), and the air outlet end of the first air exhaust pipe (3), the air outlet end of the second air exhaust pipe (4) and the air outlet end of the third air exhaust pipe (5) are all connected to the second pump body (2).

5. The vacuum system for an ingot casting furnace according to claim 4, characterized in that: It also includes a fourth tube body, the air inlet end of the fourth tube body is connected to the ingot casting furnace (20), and the air outlet end of the fourth tube body is connected to the connecting pipe (11).

6. The vacuum system for an ingot casting furnace according to claim 2 or 3, characterized in that: It also comprises a second pump body (2), wherein the second pump body (2) is connected in series between the first pump body (1) and the air extraction pipe group, and the second pump body (2) and the first pump body (1) are connected in series via a connecting pipe (11), wherein: The air inlet end of the first air exhaust pipe (3), the air inlet end of the second air exhaust pipe (4) and the air inlet end of the third air exhaust pipe (5) are all connected to the ingot casting furnace (20); the air outlet end of the first air exhaust pipe (3) and the air outlet end of the second air exhaust pipe (4) are all connected to the second pump body (2); and the air outlet end of the third air exhaust pipe (5) is connected to the connecting pipe (11).

7. A control method for a vacuum pumping system of an ingot furnace, characterized in that: include: Starting the first pump body (1); The ingot casting operation stage of the ingot casting furnace (20) is obtained, and the corresponding control valves on different exhaust pipes are controlled to open or close according to the different ingot casting operation stages to control the pressure value in the ingot casting furnace (20), wherein the ingot casting operation stage includes: exhaust stage, heating stage and crystal growth stage.

8. The control method of the vacuum pumping system of the ingot furnace according to claim 7, characterized in that: When the ingot casting operation stage is the exhaust stage, a first predetermined number of control valves are opened to allow the pressure value in the ingot casting furnace (20) to drop to a first threshold value; when the pressure value in the ingot casting furnace (20) drops to the first threshold value, a second predetermined number of control valves are opened to allow the pressure value in the ingot casting furnace (20) to drop from the first threshold value to the second threshold value.

9. The control method according to claim 8, characterized in that: When the ingot casting operation stage is a heating stage, the openings of the second predetermined number of control valves are controlled so that the pressure value in the ingot casting furnace (20) is maintained at a second threshold value.

10. The control method according to claim 8, characterized in that: When the ingot casting operation stage is the crystal growth stage, the second predetermined number of control valves are closed so that the pressure value in the ingot casting furnace (20) rises from the second threshold value to a third threshold value, wherein the third threshold value is greater than the first threshold value.

11. The control method according to claim 8, characterized in that: When the ingot casting operation stage is the exhaust stage, and the pressure value in the ingot casting furnace (20) drops from the first threshold value to the second threshold value, The second pump body (2) is opened, so that the pressure value in the ingot casting furnace (20) drops from the second threshold value to a fourth threshold value.

12. The control method according to claim 11, characterized in that: When the ingot casting operation stage is the crystal growth stage, the second pump body (2) and the second predetermined number of control valves are closed so that the pressure value in the ingot casting furnace (20) rises from the fourth threshold value to the third threshold value, wherein the third threshold value is greater than the first threshold value.

13. The control method according to claim 7, characterized in that: The starting of the first pump body (1) comprises: determining whether argon gas is filled into the ingot casting furnace (20); When argon gas is filled into the ingot casting furnace (20), the first pump body (1) is started.

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