CN220827489U - Electrode sheath, bottom heat preservation assembly and single crystal furnace - Google Patents

Abstract

The application relates to an electrode sheath, a bottom heat preservation assembly and a single crystal furnace, wherein the single crystal furnace comprises a chassis, an electrode and the bottom heat preservation assembly, a regular polygon hole for arranging the electrode sheath is formed in the bottom heat preservation assembly, the electrode sheath is arranged in the regular polygon hole, the electrode is arranged in the electrode sheath, the electrode sheath comprises at least four side walls with the same length, and the at least four side walls are connected end to end in sequence to form a closed regular polygon cylinder structure. Because the electrode sheath is regular polygon barrel-shaped structure, for cylindric electrode sheath, under the condition of equal volume, regular polygon barrel-shaped electrode sheath has longer girth to can increase the heat transfer area of electrode sheath inside and outside, and then improve heat exchange efficiency, be favorable to the degree of consistency of thermal field, and then be favorable to improving monocrystalline silicon's quality and purity.

Description

Electrode sheath, bottom heat preservation assembly and single crystal furnace

Technical Field

The application relates to the technical field of production equipment of monocrystalline silicon, in particular to an electrode sheath, a bottom heat preservation component and a monocrystalline furnace.

Background

Along with the continuous increase of the types of solar cells, the increasingly wide application range and the gradual expansion of market scale, the silicon-based cells are a main market due to the stable conversion efficiency. Monocrystalline silicon wafers are used as important materials for manufacturing silicon-based batteries, and monocrystalline silicon is mainly produced by a Czochralski process.

The Czochralski method is to melt silicon in a single crystal furnace, and gradually pull the single crystal silicon by using a rotary seed crystal. In the single crystal pulling process, the electrode is the transmitter of energy, and current passes through the electrode to transmit energy to the heater, which generates heat under the action of the current to melt the crystal. In this process, the electrode sheath serves to isolate the electrode from the furnace body. Therefore, the electrode sheath plays a crucial role in maintaining the uniformity of the thermal field of the whole furnace body.

In the related art, the electrode sheath has poor heat conduction effect, which is unfavorable for the uniformity of the thermal field.

Disclosure of Invention

Based on the above, it is necessary to provide an electrode sheath, a bottom insulation component and a single crystal furnace for solving the problems that the thermal convection effect of the electrode sheath is poor and the uniformity of a thermal field is not good.

An electrode sheath for sheathing outside an electrode, the electrode sheath comprising: at least four side walls with the same length are connected end to end in sequence to form a closed regular polygon cylinder structure.

In one embodiment, the electrode sheath comprises a carbon-carbon composite layer.

In one embodiment, the number of the side walls is four, and the four side walls are connected end to end in sequence to form a regular quadrilateral cylinder structure.

In one embodiment, two adjacent side walls are detachably connected.

In one embodiment, a protruding portion is disposed on one side, close to the last side wall, of any one of the at least four side walls connected end to end in sequence, a matching portion is disposed on one side, close to the next side wall, of the side walls, and two adjacent side walls are matched with the matching portion through the protruding portion.

In one embodiment, the protruding portion is a cylindrical structure, and the matching portion is a round hole matched with the cylindrical structure.

In one embodiment, the side wall includes a wall body and a connector, the connector is disposed on one side of the wall body along a height direction, a dimension of the connector along a thickness direction of the wall body is greater than a thickness of the wall body, the protruding portion is disposed at one end of the connector, and the mating portion is disposed at the other end of the connector.

In one embodiment, the sidewall has a thickness of 5cm to 7cm.

The bottom heat preservation subassembly, bottom heat preservation subassembly includes protective disk preforming, protective disk heat preservation, bottom heat preservation and foretell electrode sheath, protective disk preforming, protective disk heat preservation, bottom heat preservation set gradually along the direction of height, just set up the regular polygon hole that link up each other on protective disk preforming, protective disk heat preservation, the bottom heat preservation respectively, just the quantity in regular polygon hole is a plurality of, regular polygon hole with electrode sheath's size looks adaptation, so that a plurality of electrode sheath one-to-one sets up in the regular polygon is downthehole.

The single crystal furnace comprises a chassis, electrodes and the bottom heat preservation assembly, wherein the heat preservation assembly and the electrodes are respectively arranged on the chassis, and the electrodes are respectively arranged in each electrode sheath.

Above-mentioned electrode sheath, bottom heat preservation subassembly and single crystal furnace, because the electrode sheath is regular polygon barrel type structure, for cylindric electrode sheath, under the condition of equal volume, regular polygon barrel type electrode sheath has longer girth to can increase the heat transfer area of electrode sheath inside and outside, and then improve heat exchange efficiency, be favorable to the degree of consistency of thermal field, and then be favorable to improving monocrystalline silicon's quality and purity.

Drawings

Fig. 1 is a schematic structural view of an electrode sheath according to an embodiment.

Fig. 2 is an enlarged schematic view of the structure at a in fig. 1.

FIG. 3 is a schematic diagram of the bottom structure of a single crystal furnace according to an embodiment.

Fig. 4 is a schematic cross-sectional structure of fig. 3.

Reference numerals: 10. an electrode; 20. a chassis; 30. a bottom insulation assembly; 31. an electrode sheath; 32. tabletting the protective disc; 33. a protective disc heat preservation layer; 34. a bottom insulation layer; 35. a gas cylinder; 36. a middle shaft hole;

110. A first sidewall; 120. a second sidewall; 130. a third sidewall; 140. a fourth sidewall; 150. a wall body; 160. a connecting body; 161. a boss; 162. and a mating part.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

In the description of the present application, it should be understood that, if any, these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., are used herein with respect to the orientation or positional relationship shown in the drawings, these terms refer to the orientation or positional relationship for convenience of description and simplicity of description only, and do not indicate or imply that the apparatus or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

Furthermore, the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the terms "plurality" and "a plurality" if any, mean at least two, such as two, three, etc., unless specifically defined otherwise.

In the present application, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly. For example, the two parts can be fixedly connected, detachably connected or integrated; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, unless expressly stated or limited otherwise, the meaning of a first feature being "on" or "off" a second feature, and the like, is that the first and second features are either in direct contact or in indirect contact through an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that if an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. If an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein, if any, are for descriptive purposes only and do not represent a unique embodiment.

In the related art, a cylindrical electrode sheath is generally adopted, and the electrode sheath is made of quartz. The cylindrical electrode sheath has poor heat conduction effect, which is unfavorable for uniformity of a thermal field.

Referring to fig. 1 and 3, an embodiment of the present application provides an electrode sheath 31, wherein the electrode sheath 31 is configured to be sleeved outside an electrode 10, and the electrode sheath 31 includes: at least four side walls with the same length are connected end to end in sequence to form a closed regular polygon cylinder structure.

In this embodiment, since the electrode sheath 31 is of a regular polygon cylindrical structure, compared with a cylindrical electrode sheath, the regular polygon cylindrical electrode sheath 31 has a longer circumference under the condition of the same volume, so that the heat exchange area of the inner side and the outer side of the electrode sheath 31 can be increased, the heat exchange efficiency is further improved, the uniformity of a thermal field is facilitated, and the quality and the purity of monocrystalline silicon are further improved.

In addition, relative to the cylindrical electrode sheath, the joint of the two side walls of the regular polygon cylindrical structure forms an edge angle, when the electrode sheath 31 needs to be clamped by the clamp, the edge angle is favorable for positioning the fixed point by the clamp, so that the electrode sheath 31 is convenient to clamp and take, and the electrode sheath 31 is convenient to be driven to lift by the clamp; meanwhile, due to the arrangement of the edges and corners, the friction force between the clamp and the electrode sheath 31 can be increased, so that the clamping of the electrode sheath 31 is facilitated, and the clamp is further facilitated to drive the electrode sheath 31 to lift.

In some embodiments, the electrode sheath 31 comprises a carbon-carbon composite layer.

In this embodiment, the electrode sheath 31 includes a carbon-carbon composite layer. The carbon-carbon composite material layer enables the electrode sheath 31 to have the following various properties: the heat conductivity is low, the heat insulation effect is good, the heat insulation effect of the bottom heat insulation component 30 can be improved, local heating is restrained, and the seeding power in the furnace is reduced by 1Kw to 1.5Kw in theory; the elastic modulus of the carbon-carbon composite material layer is greater than or equal to 25GPa, the flexural strength is between 120MPa and 180MPa, and the tensile strength is between 100MPa and 150MPa, so that the carbon-carbon composite material layer has strong deformation resistance, strong bending resistance and strong tensile resistance compared with the quartz material layer, is not easy to deform under the action of external force, and can further prolong the service life of the electrode sheath 31; the thermal expansion coefficient is low, the damage is not easy to occur under repeated high-temperature thermal shock, and the safety is high; the oxidation resistance and the corrosion resistance are strong, the reaction of quartz and silicon can be inhibited, the increase of the oxygen content of single crystals is inhibited, and the service life of the electrode sheath 31 can be prolonged to 6 months.

In some embodiments, the number of side walls is four, the four side walls being connected end to end in sequence to enclose a regular quadrilateral cylinder-type structure.

In the present embodiment, the electrode sheath 31 is a regular quadrangular tube-shaped structure, which increases the heat exchange efficiency, and has a simple structure and high production efficiency relative to a regular polygonal tube-shaped structure having at least five side walls. Meanwhile, relative to the cylindrical structures, two adjacent cylindrical structures cannot be arranged without gaps, and the regular quadrilateral cylindrical structures are adopted, so that the two adjacent regular quadrilateral cylindrical structures can be arranged without gaps, the number of the electrodes 10 can be increased under the same space, and the production efficiency of the single crystal furnace can be improved conveniently.

In addition, compared with the cylindrical electrode sheath, the four corners of the electrode sheath 31 with the regular quadrilateral cylindrical structure are firmer, and can better bear the stress caused by thermal expansion and cold contraction of the electrode 10, so that the loss of the electrode sheath 31 is reduced, and the service life of the electrode sheath 31 is prolonged.

In some embodiments, adjacent two sidewalls are detachably connected.

In this embodiment, two adjacent lateral walls are detachably connected, when one of the lateral walls is damaged, only the damaged lateral wall can be replaced, and the whole electrode sheath 31 is not required to be replaced completely, so that the maintenance cost of the electrode sheath 31 is reduced, and the production efficiency of the single crystal furnace is improved.

In addition, two adjacent side walls can be detachably connected, so that during manufacturing, a single side wall can be manufactured firstly, and then a plurality of side walls can be connected end to end in sequence. Meanwhile, the production process of the carbon-carbon composite material layer is combined with the electrode sheath 31, so that the manufacturing cost of the electrode sheath 31 can be reduced to 1.5 times of that of quartz materials.

Further, a protruding portion 161 is arranged on one side, close to the previous side wall, of any one of the four side walls connected end to end in sequence, a matching portion 162 is arranged on one side, close to the next side wall, of the side walls, and two adjacent side walls are matched with the matching portion 162 through the protruding portion 161.

In the present embodiment, the electrode sheath 31 is described as a regular quadrangular cylindrical structure, and the electrode sheath 31 includes a first sidewall 110, a second sidewall 120, a third sidewall 130, and a fourth sidewall 140, which are sequentially connected end to end. For the second sidewall 120, the first sidewall 110 is the last sidewall, and the third sidewall 130 is the next sidewall. The side of the second side wall 120 near the first side wall 110 is provided with a protruding portion 161, the side of the first side wall 110 near the second side wall 120 is provided with a matching portion 162, and in combination with fig. 2, the side of the second side wall 120 near the third side wall 130 is provided with a matching portion 162, and the side of the third side wall 130 near the second side wall 120 is provided with a protruding portion 161, i.e. the first side wall 110, the second side wall 120 and the third side wall 130 can be matched with the matching portion 162 through the protruding portion 161 to realize connection. Also for the fourth sidewall 140, the third sidewall 130 is the last sidewall, the first sidewall 110 is the next sidewall, and the third sidewall 130, the fourth sidewall 140, and the first sidewall 110 are connected in the above manner.

Adjacent two side walls are matched with the matching part 162 through the protruding part 161 so as to realize the connection of the two side walls, and other metal components such as screws are not needed to be used for connection, so that the connection mode is simple, and the production efficiency is high. Meanwhile, as the structures of the side walls are the same, the side walls are easier to assemble and disassemble, and manpower and material resources are saved.

Specifically, the protruding portion 161 has a cylindrical structure, and the engaging portion 162 has a circular hole that engages with the cylindrical structure.

In this embodiment, the two adjacent side walls are in a matching manner with the round hole through the cylindrical structure, and the cylindrical structure can be inserted into the round hole along the same direction, so that the relative position and the angle between the two adjacent side walls are relatively stable, and deformation or loosening is not easy to occur. In addition, cylindrical structure and round hole can accurate matching processing, and because cylindrical structure and round hole direct set up on the lateral wall, two adjacent lateral walls pass through cylindrical structure and round hole lug connection, can reduce the loss of hookup location, improve the durability.

Specifically, the protruding portion 161 may be a cylindrical structure with a radius of 3cm and a height of 4 cm. The cylindrical structure can more evenly distribute the bearing pressure of the side walls without being subjected to excessive loads in a certain direction. And has stronger bending strength and bearing capacity. Meanwhile, the processing difficulty of the cylindrical structure is low, the production cost is low, and the installation and the disassembly are convenient.

In some embodiments, the side wall includes a wall body 150 and a connection body 160, the connection body 160 is disposed at one side of the wall body 150 in the height direction, the dimension of the connection body 160 in the thickness direction of the wall body 150 is greater than the thickness of the wall body 150, the protrusion 161 is disposed at one end of the connection body 160, and the mating portion 162 is disposed at the other end of the connection body 160.

In the present embodiment, the wall body 150 and the connection body 160 may be integrally manufactured, and the connection body 160 is vertically disposed above the wall body 150, thereby forming an L-shaped structure with the wall body 150. The protruding portion 161 and the fitting portion 162 are provided on the connection body 160, and the dimension of the connection body 160 in the thickness direction of the wall body 150 is larger than the thickness of the wall body 150, so that the dimension of the protruding portion 161 and the fitting portion 162 is further increased to enhance the stability of the electrode sheath 31.

Further, the thickness of the sidewall is 5cm-7cm.

In this embodiment, the thickness of the sidewall may be 5cm, 6cm, and 7cm. Wherein the use of 7cm can increase the strength and rigidity of the electrode sheath 31 and can make the electrode sheath 31 withstand greater pressure, thermal stress, and temperature variation to improve the durability of the electrode sheath 31: meanwhile, the heat capacity of the electrode sheath 31 can be improved, and the production efficiency and quality of the single crystal furnace can be improved.

Referring to fig. 3 and fig. 4, an embodiment of the present application further provides a bottom insulation assembly 30, where the bottom insulation assembly includes a tray pressing sheet 32, a tray insulation layer 33, a bottom insulation layer 34, and the electrode sheath 31 described above, where the tray pressing sheet 32, the tray insulation layer 33, and the bottom insulation layer 34 are sequentially disposed along a height direction, and the tray pressing sheet 32, the tray insulation layer 33, and the bottom insulation layer 34 are respectively provided with a plurality of regular polygon holes that are mutually communicated, and the number of the regular polygon holes is multiple, and the regular polygon holes are matched with the size of the electrode sheath 31, so that the plurality of electrode sheaths 31 are disposed in the regular polygon holes in a one-to-one correspondence manner.

In this embodiment, the protection disc pressing sheet 32 may be made of isostatic graphite, the protection disc insulating layer 33 may be made of graphite soft felt, and the bottom insulating layer 34 may be made of graphite solid felt. The protective plate heat preservation layer 33 and the bottom heat preservation layer 34 are used for reducing heat loss in the furnace.

Further, the protective plate pressing sheet 32, the protective plate heat-insulating layer 33 and the bottom heat-insulating layer 34 are respectively provided with a center shaft hole 36 which is mutually communicated, and the center shaft holes 36 are used for arranging a bracket for supporting the crucible. The guard plate pressing sheet 32, the guard plate heat-insulating layer 33 and the bottom heat-insulating layer 34 are respectively provided with mutually communicated air guide cylinders 35, the air guide cylinders 35 are used for controlling the flow and distribution of air flow in the furnace, adjusting the distribution of heat fields in the furnace, realizing more uniform heat fields, and ensuring the stability of the Czochralski single crystal process and the quality of crystal growth through the cooling and protecting effects of the air flow.

Referring to fig. 3 and 4, a single crystal furnace includes a chassis 20, electrodes 10, and a bottom insulation assembly 30, where the bottom insulation assembly 30 and the electrodes 10 are respectively disposed on the chassis 20, and each electrode sheath 31 is respectively provided with an electrode 10.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims (10)

1. An electrode sheath for sleeving on the outer side of an electrode, the electrode sheath comprising: at least four side walls with the same length are connected end to end in sequence to form a closed regular polygon cylinder structure.

2. The electrode sheath of claim 1, wherein the electrode sheath comprises a carbon-carbon composite layer.

3. The electrode sheath of claim 1, wherein the number of side walls is four, and the four side walls are connected end to end in sequence to form a regular quadrilateral cylinder.

4. The electrode sheath of claim 1, wherein adjacent two of the side walls are detachably connected.

5. The electrode sheath according to claim 4, wherein any one of at least four side walls connected end to end in sequence is provided with a convex portion on a side close to the last side wall, a fitting portion is provided on a side close to the next side wall, and two adjacent side walls are fitted with the fitting portions through the convex portions.

6. The electrode sheath of claim 5, wherein the boss is a cylindrical structure and the mating portion is a circular hole that mates with the cylindrical structure.

7. The electrode sheath according to claim 5, wherein the side wall includes a wall body and a connecting body, the connecting body is provided on one side of the wall body in a height direction, a dimension of the connecting body in a thickness direction of the wall body is larger than a thickness of the wall body, the protruding portion is provided at one end of the connecting body, and the fitting portion is provided at the other end of the connecting body.

8. The electrode sheath of claim 1, wherein the sidewall has a thickness of 5cm to 7cm.

9. The utility model provides a bottom heat preservation subassembly, its characterized in that, bottom heat preservation subassembly includes protective disk preforming, protective disk heat preservation, bottom heat preservation and the electrode sheath of any one of claims 1-8, protective disk preforming, protective disk heat preservation, bottom heat preservation set gradually along the direction of height, just protective disk preforming, protective disk heat preservation, bottom heat preservation are last to have seted up the regular polygon hole that link up each other respectively, just the quantity of regular polygon hole is a plurality of, regular polygon hole with electrode sheath's size looks adaptation, so that a plurality of electrode sheath one-to-one sets up in the regular polygon hole.

10. The single crystal furnace is characterized by comprising a chassis, electrodes and the bottom heat preservation assembly of claim 9, wherein the heat preservation assembly and the electrodes are respectively arranged on the chassis, and the electrodes are respectively arranged in each electrode sheath.