Combined heating device for single crystal furnace

Abstract

The utility model provides a combined heating device for a single crystal furnace, which comprises a main heater, a bottom heater and an auxiliary heater, the main heater, the auxiliary heater and the bottom heater are sequentially arranged from the opening end of a quartz crucible to the bottom of the quartz crucible, and the main heater and the auxiliary heater are coaxially arranged. The main heater, the auxiliary heater and the bottom heater are respectively connected with a power supply, so that the main heater, the auxiliary heater and the bottom heater can be independently controlled; the number of the main heating units of the main heater is larger than that of the auxiliary heating units of the auxiliary heater, silicon materials in the quartz crucible are heated from different positions, the upper limit of the melting power is improved, the melting temperature is effectively increased, the melting efficiency is improved, the service life of the combined heating device is prolonged, and the thermal field cost is reduced. A gap is formed between the main heating part of the main heater and the auxiliary heating part of the auxiliary heater, so that the sparking phenomenon caused by deformation contact of the main heater and the auxiliary heater in the working process is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of silicon single crystal production, in particular to a combined heating device for a single crystal furnace. Background Art

[0002] With the rapid development of the photovoltaic industry, photovoltaic manufacturing is simultaneously promoting the production concept of automation, intelligence and efficiency. Cost reduction and efficiency improvement have always been the goals pursued by the single crystal industry. As an important thermal field component in the single crystal pulling process, the heating function and service life of the heater are extremely important. At present, the main heater (short heating unit heater, the heating unit height is between 200-350mm) and the bottom heater are commonly used in the industry. They are turned on simultaneously during the melting stage. The bottom heater can be turned off during the crystal pulling stage, and only the main heater is used for heating to provide heat supply in the furnace.

[0003] Compared with the previous full-length heating unit heater, although the material processing time has increased, the oxygen content of the single crystal has been significantly improved. For N-type single crystals, oxygen content is an important technical indicator of single crystals, and its oxygen content directly affects the product qualification rate. Summary of the Invention

[0004] In view of the above problems, the present invention provides a combined heating device for a single crystal furnace to solve the above or other problems existing in the prior art.

[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is: a combined heating device for a single crystal furnace, including a main heater and a bottom heater, the main heater corresponds to the peripheral side of the quartz crucible, and the bottom heater corresponds to the bottom of the quartz crucible, and also includes a secondary heater corresponding to the peripheral side of the quartz crucible. The main heater, the secondary heater and the bottom heater are arranged in sequence from the open end to the bottom of the quartz crucible, the main heater and the secondary heater are coaxially arranged, and the main heater, the secondary heater and the bottom heater are respectively connected to a power supply, so that the main heater, the secondary heater and the bottom heater can be controlled separately; the number of main heating units of the main heater is greater than the number of secondary heating units of the secondary heater.

[0006] Furthermore, the main heater includes a main heating part and a main heating leg connected to the main heating part. The main heating part includes a plurality of main heating units connected end to end in sequence, and the width of the main heating unit gradually decreases from the main heater to the auxiliary heater.

[0007] Furthermore, the auxiliary heater includes an auxiliary heating portion and an auxiliary heating leg portion and an auxiliary transition portion both connected to the auxiliary heating portion. The auxiliary heating leg portion and the auxiliary transition portion are alternately arranged in sequence along the circumferential direction of the auxiliary heating portion.

[0008] Furthermore, the secondary transition portion corresponds to the main heating leg portion, the secondary transition portion is provided with an accommodating space, the main heating leg portion is arranged in the accommodating space, and there is a gap between the main heating leg portion and the secondary transition portion.

[0009] Furthermore, the auxiliary heating portion includes a plurality of auxiliary heating units connected end to end in sequence, and the width of the auxiliary heating unit remains unchanged along the direction from the main heater to the auxiliary heater.

[0010] Furthermore, the secondary transition part includes a first connecting member, a second connecting member and a third connecting member, one end of the first connecting member and one end of the second connecting member are both connected to the secondary heating part, the other end of the first connecting member and the other end of the second connecting member are respectively connected to the two ends of the third connecting member, and the minimum distance between the first connecting member and the second connecting member is greater than the width of the main heating leg.

[0011] Furthermore, the main heating leg is connected to the main electrode foot, which includes a bending structure and a mounting structure connected to each other. The mounting structure is connected to the electrode column, the bending structure corresponds to the third connecting member, and there is a gap between the bending structure and the third connecting member.

[0012] Furthermore, it also includes an isolating member, which is provided on the auxiliary heater and / or the main heater to isolate the main heater from the auxiliary heater, and the isolating member is a groove structure.

[0013] Furthermore, the main heater is an integrally formed structure, or the main heater is a spliced ​​structure.

[0014] Furthermore, the auxiliary heater is an integrally formed structure, or the auxiliary heater is a spliced ​​structure.

[0015] Due to the adoption of the above technical solution, the combined heating device for a single crystal furnace has a main heater, a sub-heater and a bottom heater sequentially arranged along the axial direction of the quartz crucible. The main heater and the sub-heater respectively correspond to the peripheral side surfaces of the straight wall portion of the quartz crucible. The main heater is arranged above the sub-heater, and the bottom heater corresponds to the bottom of the quartz crucible. The silicon material in the quartz crucible is heated from different positions, thereby increasing the upper limit of the melt power, effectively increasing the melt temperature, improving the melt efficiency, extending the service life of the combined heating device, and reducing the thermal field cost.

[0016] The main heater, auxiliary heater and bottom heater are connected to independent power supplies, so that the main heater, auxiliary heater and bottom heater can be selected to work separately or simultaneously, and independently controlled. During the crystal growth stage, only the main heater can be used for heating, and the auxiliary heater acts as a heat insulator to reduce the main heater from baking the bottom of the crucible, saving work time, reducing oxygen generation, and lowering the oxygen content of the single crystal;

[0017] The number of main heating units of the main heater is greater than the number of secondary heating units of the secondary heater. The heating power of the main heater and the secondary heater are controlled to be different, and the heat provided to the quartz crucible is different. There is a gap between the main heating part of the main heater and the secondary heating part of the secondary heater to avoid the occurrence of sparks caused by deformation and contact between the main heater and the secondary heater during operation;

[0018] The main heating unit of the main heater has a gradient structure. The width of the main heating unit gradually decreases from the main heater to the auxiliary heater, forming a temperature gradient in the axial direction, which is beneficial to improving the single crystal crystallization rate. At the same time, while ensuring that the temperature environment in the single crystal furnace remains unchanged, the weight of the main heating unit is reduced to avoid deformation of the main heater during use.

[0019] The main electrode pin of the main heater adopts a curved structure so that the main electrode pin does not contact the third connecting piece of the secondary transition part, avoiding the need to increase the height of the electrode column to achieve the installation of the main heater and avoid affecting the travel of the crucible;

[0020] An isolation piece is provided between the main electrode pin of the main heater and the secondary transition portion to prevent the main heater and the secondary heater from deforming and contacting during operation, thereby preventing sparking. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a structural schematic diagram of a combined heating device according to an embodiment of the present invention when it is installed outside a quartz crucible;

[0022] Figure 2 This is a structural schematic diagram of a combined heating device according to an embodiment of the present invention from one angle (without a spacer);

[0023] Figure 3 This is a schematic structural diagram of a combined heating device according to an embodiment of the present invention from another angle (without the isolation member);

[0024] Figure 4 It is a structural schematic diagram of an isolation member according to an embodiment of the present invention.

[0025] In the picture:

[0026] 1. Main heater 2. Auxiliary heater 3. Bottom heater

[0027] 10. Main heating unit 11. Main heating leg 12. Main electrode foot

[0028] 20. Secondary heating unit 21. Secondary transition section 22. Secondary heating leg section

[0029] 4. Isolation parts DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0031] Figure 1 A schematic structural diagram of an embodiment of the present invention is shown. This embodiment relates to a combined heating device for a single crystal furnace. The combined heating device is installed on the outside of a crucible assembly consisting of a quartz crucible and a carbon-carbon crucible. During the Czochralski single crystal pulling process, the silicon material in the quartz crucible is heated. The device comprises a main heater and a sub-heater. At different stages of Czochralski single crystal pulling, the sub-heater can be selected to operate according to actual needs, thereby extending the service life of the combined heating device, reducing thermal field costs, and lowering the oxygen content of the single crystal.

[0032] A combined heating device for a single crystal furnace, such as Figure 1-3 As shown, it includes a main heater 1 and a bottom heater 3, and also includes a sub-heater 2. The main heater 1, the sub-heater 2 and the bottom heater 3 are arranged in sequence along the open end to the bottom of the quartz crucible. The main heater 1 and the sub-heater 2 are coaxially arranged. The main heater 1 and the sub-heater 2 are both annular structures. When the main heater 1 and the sub-heater 2 are arranged, the main heater 1 and the sub-heater 2 are coaxially arranged with the quartz crucible. The main heater 1 corresponds to the circumferential side of the quartz crucible, and the sub-heater 2 corresponds to the circumferential side of the quartz crucible. Along the axial direction of the quartz crucible, the sub-heater 2 is arranged below the main heater 1. The main heater 1 and the sub-heater 2 can heat the quartz crucible from the circumferential side respectively. The bottom heater 3 corresponds to the bottom of the quartz crucible and heats the quartz crucible from the bottom, so as to heat the silicon material in the quartz crucible from different positions, so that the silicon material in the quartz crucible is heated evenly.

[0033] In some feasible embodiments, preferably, the sub-heater 2 corresponds to the straight wall portion of the quartz crucible, and the main heater 1 corresponds to the straight wall portion of the quartz crucible.

[0034] The main heater 1, the auxiliary heater 2 and the bottom heater 3 are respectively connected to a power supply, so that the main heater 1, the auxiliary heater 2 and the bottom heater 3 work separately, that is, the main heater 1 is connected to one power supply, the auxiliary heater 2 is connected to another power supply, and the bottom heater 3 is connected to another power supply, so that the main heater 1, the auxiliary heater 2 and the bottom heater 3 are respectively controlled by independent power supplies, and the main heater 1, the auxiliary heater 2 and the bottom heater 3 work separately without interfering with each other. According to actual process requirements, a variety of heating working modes can be realized, including: the main heater 1 and the auxiliary heater 2 work at the same time, or, the main heater 1 and the bottom heater 3 work at the same time, or, the auxiliary heater 2 and the bottom heater 3 work at the same time, or, the main heater 1, the auxiliary heater 2 and the bottom heater 3 work at the same time, or, any one of the main heater 1, the auxiliary heater 2 and the bottom heater 3 works, so as to meet the temperature requirements of different processes in the single crystal pulling process.

[0035] like Figure 2 and 3 As shown, the main heater 1 and the auxiliary heater 2 mentioned above both have multiple heating units 10 and 20, and the number of the main heating units 10 of the main heater 1 is greater than the number of the auxiliary heating units 20 of the auxiliary heater 2, so as to control the heating power of the main heater 1 and the heating power of the auxiliary heater 2 to be different, so that the main heater 1 and the auxiliary heater 2 provide different heat to the quartz crucible to meet the heating temperature requirements of different positions of the quartz crucible.

[0036] When the combined heating device for a single crystal furnace is used, the main heater 1 is connected to the corresponding electrode column, and the main heater 1 is mounted on the outer peripheral side of the quartz crucible. The main heater 1 corresponds to the peripheral side of the upper half of the quartz crucible to heat the quartz crucible; the auxiliary heater 2 is connected to the corresponding electrode column, and the auxiliary heater 2 is mounted on the outer peripheral side of the quartz crucible. The auxiliary heater 2 is located below the main heater 1, and the auxiliary heater 2 corresponds to the peripheral side of the lower half of the quartz crucible to heat the quartz crucible; the bottom heater 3 is installed below the quartz crucible. , corresponding to the bottom of the quartz crucible, the bottom heater 3 is connected to the corresponding electrode column to heat the bottom of the quartz crucible. Moreover, the main heater 1, the auxiliary heater 2 and the bottom heater 3 are respectively connected to the corresponding power supply through the corresponding electrode column, and the corresponding power supply controls the operation of the corresponding heater. During the Czochralski single crystal pulling process, at different process stages, according to actual temperature requirements, the main heater 1 and / or the auxiliary heater 2 and / or the bottom heater 3 are controlled to operate, thereby heating different positions of the quartz crucible and meeting the process requirements of Czochralski single crystal pulling.

[0037] Specifically, the main heater 1 includes a main heating part and a main heating leg 11 connected to the main heating part. The main heating part heats the quartz crucible. The main heating leg 11 is used to connect with the electrode column and control the height of the main heating part, thereby ensuring the position of the main heating part relative to the quartz crucible. The main heating part is an annular structure, which is adapted to the shape of the quartz crucible, so that the main heating part is arranged outside the quartz crucible and corresponds to the peripheral side surface of the quartz crucible to heat the quartz crucible. Along the circumferential direction of the quartz crucible, the main heating part includes a plurality of main heating units 10 connected end to end in sequence. Each main heating unit 10 is arranged along the axial direction of the quartz crucible. When the multiple main heating units 10 are connected, the multiple main heating units 10 are arranged in sequence along the circumferential direction of the quartz crucible, and the corresponding one ends of the two adjacent main heating units 10 are located on the same arc, and the corresponding other ends of the two adjacent main heating units 10 are also located on the same arc, thereby making the corresponding same ends of the multiple main heating units 10 located on the same circumference, and the corresponding other ends of the multiple main heating units 10 are also located on the same circumference. The multiple main heating units 10 constitute an annular structure with a circular cross-section.

[0038] The number of the main heating units 10 is selected according to the width of the main heating units 10 and the circumference of the quartz crucible, and no specific requirements are given here.

[0039] The main heating unit 10 has a gradient structure, and the width of the main heating unit 10 gradually decreases from the main heater 1 to the auxiliary heater 2. On the premise of ensuring that the temperature in the single crystal furnace remains unchanged, the weight of each main heating unit 10 of the main heater 1 is reduced, and the main heater 1 is prevented from being deformed during use. At the same time, a temperature gradient can be formed in the axial direction to improve the crystallization rate of the single crystal.

[0040] Specifically, the main heating unit 10 includes a first sub-heating part and a second sub-heating part, one end of the first sub-heating part is connected to one end of the second sub-heating part, the other end of the first sub-heating part is connected to the main heating unit 10 adjacent to one side thereof, and the other end of the second sub-heating part is connected to the main heating unit 10 adjacent to one side thereof. The first sub-heating part and the second sub-heating part are arranged along the circumferential direction of the quartz crucible, and there is a gap between the first sub-heating part and the second sub-heating part, and the end of the first sub-heating part connected to the adjacent main heating unit 10 and the end of the second sub-heating part connected to the adjacent main heating unit 10 are located on the same side of the connection, constructing a main heating unit 10 structure with an approximately U-shaped structure. The size of the gap between the first sub-heating part and the second sub-heating part is selected according to actual needs, and no specific requirements are made here.

[0041] In order to facilitate the connection of the first sub-heating section and the second sub-heating section with the corresponding adjacent main heating units 10, the first sub-heating section and the second sub-heating section each include a main heating element and a sub-heating element arranged in an intersecting manner, one end of the main heating element is connected to one end of the sub-heating element. Preferably, the main heating element and the sub-heating element are arranged vertically to form an approximately L-shaped structure of the first sub-heating section and the second sub-heating section. The sub-heating element of the first sub-heating section and the sub-heating element of the second sub-heating section are arranged relatively far apart, the sub-heating element of the first sub-heating section is arranged on a side surface of the main heating element away from the second sub-heating section, and the sub-heating element of the second sub-heating section is arranged on a side surface of the main heating element away from the first sub-heating section, so that the first sub-heating section and the second sub-heating section are respectively connected to the adjacent main heating units 10 on the corresponding sides.

[0042] The main heating element of the first sub-heating section and the main heating element of the second sub-heating section are both arranged along the axial direction of the quartz crucible. The end of the main heating element of the first sub-heating section not provided with the sub-heating element is fixedly connected to the end of the main heating element of the second sub-heating section not provided with the sub-heating element. The main heating element of the first sub-heating section and the main heating element of the second sub-heating section are both plate-shaped structures. The width of the main heating element of the first sub-heating section and the width of the main heating element of the second sub-heating section decrease in sequence from the main heater 1 to the auxiliary heater 2, thereby reducing the weight of the main heating unit 10. In some feasible embodiments, the opposite sides of the main heating element of the first sub-heating section and the main heating element of the second sub-heating section are arranged in parallel, and the relatively distant sides are arranged to intersect, so that the connection between the main heating element of the first sub-heating section and the main heating element of the second sub-heating section forms a rounded corner structure or a sharp corner structure, while ensuring that the gap between the two main heating elements of the main heating unit 10 does not change along the axial direction of the quartz crucible. The fixed connection method of the two main heating elements is preferably integrally formed.

[0043] The number of the above-mentioned main heating legs 11 is multiple, and the multiple main heating legs 11 are all arranged on the same side of the main heating part. The main heating legs 11 are arranged along the axial direction of the main heating part, and each main heating leg 11 is arranged between two adjacent main heating units 10. The main heating legs 11 are respectively connected to the two adjacent main heating units 10. When the multiple main heating legs 11 are set, they are arranged in pairs, so that the main heating part is evenly stressed and not easily deformed. The number of main heating legs 11 is selected according to actual needs, and no specific requirements are made here.

[0044] In some feasible embodiments, there are two main heating legs 11 , which are arranged opposite to each other.

[0045] The above-mentioned auxiliary heater 2 includes an auxiliary heating part and an auxiliary heating leg 22 and an auxiliary transition part 21 connected to the auxiliary heating part. The auxiliary heating leg 22 and the auxiliary transition part 21 are alternately arranged in sequence along the circumferential direction of the auxiliary heating part. The auxiliary heating part is a ring structure. The number of auxiliary heating legs 22 and auxiliary transition parts 21 is multiple. Multiple auxiliary heating legs 22 and auxiliary transition parts 21 are alternately arranged in sequence. A secondary transition part 21 is arranged between two adjacent auxiliary heating legs 22, and a secondary heating leg 22 is arranged between two adjacent auxiliary transition parts 21. Multiple auxiliary heating legs 22 and multiple auxiliary transition parts 21 are all arranged on the same side of the auxiliary heating part.

[0046] The auxiliary heating section includes a plurality of auxiliary heating units 20 connected end to end in sequence. The plurality of auxiliary heating units 20 are arranged in sequence along the circumferential direction of the quartz crucible to construct an annular auxiliary heating section. The auxiliary heating section has the same structure as the main heating section and will not be described in detail here. The difference is that the structure of the auxiliary heating unit 20 is different from that of the main heating unit 10. In the auxiliary heating section, the width of the auxiliary heating unit 20 remains unchanged along the direction from the main heater 1 to the auxiliary heater 2, that is, the auxiliary heating unit 20 is a uniform width structure. The first sub-heating section of the auxiliary heating unit 20 is arranged in parallel with the second sub-heating section. The main heating element of the first sub-heating section and the main heating element of the second sub-heating section are both uniform width structures, and the connection between the two main heating elements forms a flat angle structure.

[0047] The auxiliary heating leg 22 is arranged between two adjacent auxiliary heating units 20, and the auxiliary heating leg 22 is respectively connected to the two adjacent auxiliary heating units 20. The auxiliary heating leg 22 controls the height of the auxiliary heating part to facilitate the installation of the main heater 1 and the auxiliary heater 2. The auxiliary transition part 21 is arranged between two adjacent auxiliary heating units 20, and the auxiliary transition part 21 is respectively connected to the two connected auxiliary heating units 20. There are multiple auxiliary heating legs 22. When multiple auxiliary heating legs 22 are arranged, they are arranged in pairs, so that the auxiliary heating part is evenly stressed and not easily deformed. The number of auxiliary heating legs 22 is selected according to actual needs, and no specific requirements are made here. When the auxiliary heater 2 is installed, the multiple auxiliary heating legs 22 and the multiple main heating legs 11 are staggered with each other, that is, the multiple main heating legs 11 and the multiple auxiliary heating legs 22 are staggered with each other, which facilitates the installation of the main heater 1 and the auxiliary heater 2, and also avoids the main heating legs 11 and the auxiliary heating legs 22 from contacting due to deformation during the operation of the main heater 1 and the auxiliary heater 2, resulting in sparks.

[0048] The above-mentioned main heating leg 11 and auxiliary heating leg 22 are both long plate-like structures and have a certain length. The length of the main heating leg 11 is greater than the length of the auxiliary heating leg 22, so that the auxiliary heating part is arranged below the main heating part. The width of the main heating leg 11 and the width of the auxiliary heating leg 22 are selected according to actual needs, and no specific requirements are made here.

[0049] When the secondary heater 2 is installed, the secondary transition portion 21 corresponds to the primary heating leg 11. The secondary transition portion 21 has a storage space, and the primary heating leg 11 is located within the storage space of the secondary transition portion 21. A gap is provided between the secondary transition portion 21 and the primary heating leg 11 to prevent the secondary transition portion 21 and / or the primary heating leg 11 from deforming and contacting during operation of the primary and secondary heaters 1 and 2, leading to sparks. The gap between the secondary transition portion 21 and the primary heating leg 11 is selected based on actual needs and is not specified here.

[0050] The secondary transition portion 21 includes a first connecting member, a second connecting member and a third connecting member. One end of the first connecting member and one end of the second connecting member are both connected to the secondary heating portion, and the other end of the first connecting member and the other end of the second connecting member are respectively connected to the two ends of the third connecting member. That is, the secondary transition portion 21 is a structure that is approximately U-shaped. The lengths of the first connecting member and the second connecting member are consistent, and the lengths of the first connecting member and the second connecting member are not greater than the length of the secondary heating leg 22, and will not interfere with the connection between the secondary heating leg 22 and the corresponding electrode column. The first connecting member and the second connecting member can be arranged in parallel or in intersection, depending on actual needs. The minimum distance between the first connecting member and the second connecting member is greater than the width of the main heating leg 11, so that the main heating leg 11 can be arranged between the first connecting member and the second connecting member when the main heater 1 and the auxiliary heater 2 are installed. Neither the first connecting member nor the second connecting member contacts the main heating leg 11, avoiding sparks caused by contact between the main heater 1 and the auxiliary heater 2 during operation, and not interfering with the installation of the main heater 1 and the auxiliary heater 2. In some feasible embodiments, preferably, the first connecting member and the second connecting member are arranged in parallel.

[0051] In order to connect the main heater 1 with the corresponding electrode column, the main heating leg 11 is connected to the main electrode foot 12, and the main electrode foot 12 is connected to the corresponding electrode column so that the main heater 1 is powered by electricity. In order to make the structure of the entire heater compact and to avoid interference with the crucible's travel by raising the height of the electrode column to achieve connection with the main electrode foot 12, the position of the main electrode foot 12 corresponds to the third connecting piece of the secondary transition part 21. In order to avoid contact between the main electrode foot 12 and the third connecting member of the secondary transition part 21, there is a gap between the main electrode foot 13 and the third connecting member. The main electrode foot 12 includes a connected bending structure and a mounting structure. The mounting structure is connected to the electrode column. There is a gap between the bending structure and the third connecting member. The gap is selected and set according to actual needs. The mounting structure is a plate structure with a mounting hole, and the mounting structure is perpendicular to the main heating leg 11 so that the mounting structure is connected to the electrode column; the bending structure is a plate structure with a certain curvature, and its curvature is selected according to actual needs, so that the bending structure can bypass the third connecting member and connect with the mounting structure. The part of the bending structure corresponding to the third connecting member is suspended above and around the third connecting member, and crosses the third connecting member from above without contact.

[0052] Further optimization scheme, such as Figure 4 As shown, the combined heating device also includes an isolating member 4, which is provided on the auxiliary heater 2 and / or the main heater 1 to isolate the main heater 1 from the auxiliary heater 2 to avoid sparks caused by contact between the main heater 1 and the auxiliary heater 2 during operation. The isolating member 4 can be provided on the auxiliary heater 2. In this case, the isolating member 4 can be provided on the third connecting member of the auxiliary transition portion 21; or, the isolating member 4 can be provided on the main heater 1. In this case, the isolating member 4 can be provided on the curved structure of the main electrode foot 12; or, the isolating member 4 is provided in multiple numbers and can be provided on the main heater 1 and the auxiliary heater 2 respectively. In this case, an isolating member 4 is provided on the third connecting member of the auxiliary transition portion 21, and an isolating member 4 is provided on the curved structure of the main electrode foot 12; the setting position of the isolating member 4 is selected according to actual needs, and no specific requirements are made here.

[0053] The isolator 4 is a slot structure, which can be a straight slot structure or a curved slot structure. The structure is selected according to the structural shape of the installation location, and no specific requirements are made here. In order to facilitate the installation of the isolator 4, the isolator 4 is provided with a mounting slot, and along the length direction of the mounting slot, the two ends of the mounting slot are connected to the outside world, that is, the isolator 4 includes a bottom plate and two side plates arranged on the same side of the bottom plate, the two side plates are respectively arranged perpendicular to the bottom plate, and the two side plates are respectively arranged at a set of opposite sides of the bottom plate, constructing an isolator 4 structure with a concave cross-sectional shape, so that the isolator 4 can be clamped at the corresponding position.

[0054] Further optimization scheme, in order to prevent the isolating member 4 from falling off from the main heater 1 or the auxiliary heater 2 after installation, the isolating member 4 is also provided with an installation side groove, and there are two installation side grooves, which are respectively installed at the two ends of the installation groove, and the axis of the installation side groove is perpendicular to the axis of the installation groove. The installation side groove is connected to the installation groove, so that the two ends of the installation groove are connected to the outside world through the installation side groove, and the installation side groove does not interfere with the installation of the installation groove. Along the length direction of the installation side groove, the two ends of the installation side groove are respectively connected to the outside world, so that the installation side groove and the corresponding position of the main heater 1 or the auxiliary heater 2 are clamped, and the installation of the isolating member 4 is further limited and fixed. The installation side groove is fixedly connected to the installation groove, and the fixed connection method is preferably integrally formed. The installation groove is fixedly connected to the installation side groove, and the fixed connection method is preferably integrally formed.

[0055] The isolating member 4 serves as an isolation member, and can prevent sparks from occurring when the corresponding parts of the main heater 1 and the auxiliary heater 2 come into contact through the isolating member 4. The isolating member 4 is made of an insulating material that can insulate and prevent electrical conduction. For example, the isolating member 4 can be made of plastic.

[0056] The main heater 1 is an integrally formed structure, or a spliced ​​structure, which is selected according to actual needs and is not specifically required here. When the main heater 1 is a spliced ​​structure, it includes multiple main splicing parts, which are arranged in sequence along the circumferential direction of the quartz crucible. The multiple main splicing parts can be connected by bolts and other connectors to form a main heater 1 with an annular structure. In this case, some or all of the multiple main splicing parts are connected to the main heating leg 11; or there is no connection between the multiple main splicing parts. In this case, each main splicing part is connected to a main heating leg 11.

[0057] The above-mentioned auxiliary heater 2 is an integrally formed structure, or the auxiliary heater 2 is a splicing structure, which is selected according to actual needs and no specific requirements are made here. When the auxiliary heater 2 is a splicing structure, it includes multiple auxiliary splicing parts, and the multiple auxiliary splicing parts are arranged in sequence along the circumferential direction of the quartz crucible. The multiple auxiliary splicing parts can be connected by connecting parts such as bolts to form an auxiliary heater 2 with an annular structure. In this case, some or all of the multiple auxiliary splicing parts are connected to the auxiliary heating leg 22; or there is no connection relationship between the multiple auxiliary splicing parts. In this case, each auxiliary splicing part is connected to an auxiliary heating leg 22.

[0058] The above-mentioned bottom heater 3 is the bottom heater 3 in the prior art, and its specific structure is not described here any more.

[0059] When the combined heating device for a single crystal furnace is in use, the bottom heater 3 is connected to the corresponding electrode column, and the electrode column connected to the bottom heater 3 is connected to a power supply to supply power to the bottom heater 3; the auxiliary heater 2 is connected to the corresponding electrode column, and the electrode column connected to the auxiliary heater 2 is connected to another power supply to supply power to the auxiliary heater 2; the main heater 1 is connected to the corresponding electrode column, and the electrode column connected to the main heater 1 is connected to another power supply to supply power to the main heater 1. When the main heater 1 is installed, the main heater 1 and the auxiliary heater 2 are arranged along the axis of the quartz crucible, the main heater 1 is arranged above the auxiliary heater 2, and there is a gap between the lower end of the main heating part of the main heater 1 and the upper end of the auxiliary heating part of the auxiliary heater 2 to avoid the main heater 1 and the auxiliary heater 2 from contacting each other during operation and causing sparks. At the same time, the main heating leg 11 is arranged at the auxiliary transition part 21, and according to actual needs, an isolation part 4 is installed on the third connecting piece and / or the bent structure to avoid the main electrode foot 12 from contacting the third connecting piece of the auxiliary transition part 21 and causing sparks during operation.

[0060] The main heater 1, auxiliary heater 2 and bottom heater 3 are respectively connected to independent power supplies. During the single crystal pulling process, according to the temperature requirements of the process, the main heater 1, auxiliary heater 2 and bottom heater 3 can be selectively controlled to work separately or simultaneously to meet the process requirements of single crystal pulling.

[0061] Due to the adoption of the above technical scheme, the combined heating device for the single crystal furnace has a main heater, an auxiliary heater and a bottom heater which are arranged in sequence along the axial direction of the quartz crucible. The main heater and the auxiliary heater correspond to the peripheral side surfaces of the straight wall part of the quartz crucible respectively. The main heater is arranged above the auxiliary heater, and the bottom heater corresponds to the bottom of the quartz crucible. The silicon material in the quartz crucible is heated from different positions, thereby increasing the upper limit of the melt power, effectively increasing the melt temperature, improving the melt efficiency, and increasing the service life of the combined heating device, and reducing the thermal field cost; the main heater, auxiliary heater and bottom heater are respectively connected to independent power supplies, so that the main heater, auxiliary heater and bottom heater can be selected to work separately or simultaneously and be independently controlled. During the crystal growth stage, only the main heater can be used for heating, and the auxiliary heater serves as a heat insulation component to reduce the main heater from baking the bottom of the crucible, saving labor time, reducing oxygen generation, and reducing the oxygen content of the single crystal; the number of main heating units of the main heater is greater than the number of auxiliary heating units of the auxiliary heater The amount is used to control the heating power of the main heater and the auxiliary heater to be different, and the heat provided to the quartz crucible is different. There is a gap between the main heating part of the main heater and the auxiliary heating part of the auxiliary heater to avoid the main heater and the auxiliary heater from deforming and contacting during operation to cause sparking; the main heating unit of the main heater is a gradient structure, and the width of the main heating unit gradually decreases along the direction from the main heater to the auxiliary heater, forming a temperature gradient in the axial direction, which is beneficial to improving the crystallization rate of single crystals. At the same time, under the premise of ensuring that the temperature environment in the single crystal furnace remains unchanged, the weight of the main heating unit is reduced to avoid deformation of the main heater during use; the main electrode foot of the main heater adopts a curved structure, so that the main electrode foot does not contact the third connecting piece of the auxiliary transition part, avoiding the installation of the main heater by raising the height of the electrode column, and avoiding affecting the stroke of the crucible; an isolation piece is provided between the main electrode foot of the main heater and the auxiliary transition part to avoid deformation and contact between the main heater and the auxiliary heater during operation to cause sparking.

[0062] The above embodiments of the present invention are described in detail. However, the above contents are only preferred embodiments of the present invention and should not be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A combined heating device for a single crystal furnace, comprising a main heater and a bottom heater, wherein the main heater corresponds to the peripheral side of a quartz crucible, and the bottom heater corresponds to the bottom of the quartz crucible, characterized in that: It also includes a secondary heater corresponding to the peripheral side of the quartz crucible, the main heater, the secondary heater and the bottom heater are arranged in sequence along the open end to the bottom of the quartz crucible, the main heater and the secondary heater are coaxially arranged, the main heater, the secondary heater and the bottom heater are respectively connected to a power supply, so that the main heater, the secondary heater and the bottom heater can be controlled separately; the number of main heating units of the main heater is greater than the number of secondary heating units of the secondary heater.

2. The combined heating device for a single crystal furnace according to claim 1, characterized in that: The main heater includes a main heating part and a main heating leg connected to the main heating part. The main heating part includes a plurality of main heating units connected end to end in sequence. The width of the main heating unit gradually decreases along the direction from the main heater to the auxiliary heater.

3. The combined heating device for a single crystal furnace according to claim 2, characterized in that: The auxiliary heater includes an auxiliary heating portion, and an auxiliary heating leg portion and an auxiliary transition portion both connected to the auxiliary heating portion. The auxiliary heating leg portion and the auxiliary transition portion are alternately arranged in sequence along the circumferential direction of the auxiliary heating portion.

4. The combined heating device for a single crystal furnace according to claim 3, characterized in that: The secondary transition portion corresponds to the main heating leg portion, and the secondary transition portion is provided with a receiving space. The main heating leg portion is provided in the receiving space, and there is a gap between the main heating leg portion and the secondary transition portion.

5. The combined heating device for a single crystal furnace according to claim 3, characterized in that: The auxiliary heating portion includes a plurality of auxiliary heating units connected end to end in sequence, and the width of the auxiliary heating unit remains constant along the direction from the main heater to the auxiliary heater.

6. The combined heating device for a single crystal furnace according to any one of claims 3 to 5, characterized in that: The secondary transition part includes a first connecting member, a second connecting member and a third connecting member, one end of the first connecting member and one end of the second connecting member are both connected to the secondary heating part, the other end of the first connecting member and the other end of the second connecting member are respectively connected to the two ends of the third connecting member, and the minimum distance between the first connecting member and the second connecting member is greater than the width of the main heating leg.

7. The combined heating device for a single crystal furnace according to claim 6, characterized in that: The main heating leg is connected to a main electrode foot, and the main electrode foot includes a connected bending structure and a mounting structure. The mounting structure is connected to the electrode column, and the bending structure corresponds to the third connecting member, and there is a gap between the bending structure and the third connecting member.

8. The combined heating device for a single crystal furnace according to any one of claims 1 to 5 and 7, characterized in that: It also includes an isolation member, which is provided on the secondary heater and / or the main heater to isolate the main heater from the secondary heater, and the isolation member is a groove structure.

9. The combined heating device for a single crystal furnace according to claim 1, characterized in that: The main heater is an integrally formed structure, or the main heater is a spliced ​​structure.

10. The combined heating device for a single crystal furnace according to claim 9, characterized in that: The auxiliary heater is an integrally formed structure, or the auxiliary heater is a spliced ​​structure.

Images