Thermal field structure for single crystal furnace and single crystal furnace

Abstract

The thermal field structure comprises a heating assembly and a heat preservation assembly, the heating assembly comprises a heating part support and a heating part, the heat preservation assembly comprises a heat preservation inner layer main body and a heat preservation outer layer main body, and the heating part is arranged on the inner side of the heat preservation inner layer main body; the heat preservation inner layer body and the heat preservation outer layer body are both of an annular structure, a gap is formed between the heat preservation inner layer body and the heat preservation outer layer body, a first opening part is formed in the heat preservation inner layer body, the heating part support is arranged in the gap between the heat preservation inner layer body and the heat preservation outer layer body, and one end of the heating part support penetrates through the opening part to be connected with the heating part. By designing the heater with a special structure and the double-layer heat preservation cylinder and placing the heating part bracket between the double-layer heat preservation cylinder, the problem of non-uniformity of thermal field temperature distribution caused by heating of the heating part bracket is solved on the premise of not influencing heating of a heating area of the heater, and the purposes of improving the radial temperature distribution uniformity of the thermal field and improving the thermal efficiency are achieved. Crystal growth conditions are improved, and the crystallization rate is increased.

Description

Technical Field

[0001] This utility model relates to the technical field of hot field in single crystal furnaces, specifically to a hot field structure for single crystal furnaces and a single crystal furnace. Background Technology

[0002] The Czochralski method is currently the most widely used method for growing solar-grade monocrystalline silicon in the photovoltaic industry. In the Czochralski method, the heat source for the entire thermal field comes from the heater. In order to ensure the crystallization process of the round rod, crystal rotation and crucible rotation are usually used to ensure the uniformity of the thermal field temperature during the growth of monocrystalline silicon using the Czochralski method.

[0003] Existing single-crystal furnace heaters include a heater ring and heater legs located below the heater ring. The heat generated by the heater legs increases the heat in the lower part and bottom of the crucible, increasing the reaction between the crucible and the silicon solution. On the other hand, the heat generated by the heater legs is unevenly distributed along the circumference of the crucible, resulting in uneven heating in the lower part and bottom of the crucible and increasing the convection of the silicon solution inside the crucible. Utility Model Content

[0004] The purpose of this invention is to provide a thermal field structure for a single crystal furnace and a single crystal furnace, so as to solve the problem that the heat generated by the existing heater legs affects the thermal field of the lower part and bottom of the crucible.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a thermal field structure for a single crystal furnace, comprising a heating component and a heat preservation component. The heating component includes a heating element support and a heating element. The heat preservation component includes an inner heat preservation layer and an outer heat preservation layer. The heating element is disposed inside the inner heat preservation layer. Both the inner and outer heat preservation layers are annular structures with a gap between them. A first opening is provided on the inner heat preservation layer. The heating element support is disposed in the gap between the inner and outer heat preservation layers and one end passes through the first opening and is connected to the heating element.

[0006] Furthermore, the insulation component also includes a second connecting portion, which is disposed at the upper and lower ends of the inner insulation layer body and the outer insulation layer body, and radially covers the gap between the inner insulation layer body and the outer insulation layer body.

[0007] Furthermore, the heating element bracket includes a support portion and a first connecting portion. The support portion extends vertically and is disposed in the gap between the inner insulation layer body and the outer insulation layer body. The first connecting portion extends radially and is connected to the support portion at one end and to the heating element at the other end through the first opening.

[0008] Furthermore, a bent portion is provided at the bottom of the support portion, and the bent portion bends inward in the horizontal direction.

[0009] Furthermore, the inner insulating layer body is provided with a third opening, and the bent portion bends inward and passes through the third opening to connect with the electrode.

[0010] Furthermore, the insulation component is divided into an upper insulation section, a middle insulation section, and a lower insulation section along the axial direction. The first opening is provided on the inner insulation layer of the upper insulation section, and the third opening is provided on the inner insulation layer of the lower insulation section.

[0011] Furthermore, the lower end of the upper insulation section, the upper and lower ends of the middle insulation section, and the upper end of the lower insulation section are all provided with the second connecting portion, and the second connecting portion provided on the lower end of the upper insulation section, the upper and lower ends of the middle insulation section, and the upper end of the lower insulation section are all provided with a second opening through which the heating part bracket passes.

[0012] Furthermore, multiple heating element supports are provided and are evenly distributed along the circumference of the heating element.

[0013] Furthermore, both the inner and outer walls of the inner and outer insulation layers are provided with insulation coatings.

[0014] Another objective of this embodiment is to provide a single crystal furnace having the above-described thermal field structure for a single crystal furnace.

[0015] Beneficial effects

[0016] This invention provides a thermal field structure for a single crystal furnace, which has the following advantages:

[0017] This uniformly heated thermal field structure, through the design of a specially structured heater and a double-layered insulation cylinder, places the heating element support between the double-layered insulation cylinder. Without affecting the heating of the heater's heating zone, it eliminates the problem of uneven temperature distribution in the thermal field caused by the heating element support, thereby improving the uniformity of radial temperature distribution in the thermal field, improving crystal growth conditions, and increasing the crystal formation rate. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the thermal field assembly of the thermal field structure for a single crystal furnace proposed in this utility model.

[0019] Figure 2 This is a schematic diagram of the heating assembly proposed in this utility model;

[0020] Figure 3 This is a schematic diagram of the structure of the heat-insulating upper section proposed in this utility model;

[0021] Figure 4This is a schematic diagram of the structure of the heat-insulating middle section proposed in this utility model;

[0022] Figure 5 This is a schematic diagram of the structure of the heat-insulating lower section proposed in this utility model.

[0023] In the diagram: Heating component-1; Heating bracket-10; Support part-11; Bending part-11-1; First connecting part-12; Heating part-13; Insulation component-2; Insulation inner layer main body-21; Insulation outer layer main body-22; Second connecting part-23; First opening-24; Second opening-25; Third opening-26; Upper insulation section-A; Middle insulation section-B; Lower insulation section-C. Detailed Implementation

[0024] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0025] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0026] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0027] This utility model is described in detail with reference to the schematic diagrams. When describing the embodiments of this utility model, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, deviating from the general scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this utility model. In actual manufacturing, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0028] Furthermore, in the description of this utility model, it should be noted that the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this utility model should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integrated connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0030] Example 1

[0031] Please see Figures 1-5 This utility model provides a technical solution: a thermal field structure for a single crystal furnace, including a heating component 1 and a heat preservation component 2. The heating component 1 includes a heating support 10 and a heating part 13. One end of the heating support 10 is connected to the heating part 13, and the other end is connected to an electrode. Heating is performed through the heating part 13. The heating support 10 provides support and power to the heating part 13. The heat preservation component 2 includes an inner heat preservation body 21 and an outer heat preservation body 22. The heat preservation component 2 is a double-layer heat preservation structure, which can improve the thermal field heat preservation performance, reduce the power consumption of the same diameter, and achieve the purpose of energy saving and consumption reduction. Furthermore, the inner heat preservation body 21 is closer to the central axis of the single crystal furnace than the outer heat preservation body 22. The heating part 13 is positioned... The inner insulating layer 21 is located inside the heating element 13 to heat the crucible of the single crystal furnace. The inner insulating layer 21 and the outer insulating layer 22 are annular structures with a radial gap between them. The inner insulating layer 21 has a first opening 24. The heating element support 10 is located in the gap between the inner insulating layer 21 and the outer insulating layer 22, and one end passes through the first opening 24 and is connected to the heating element 13. Since the heating element support 10 also dissipates heat, placing the heating element support 10 in the gap between the inner insulating layer 21 and the outer insulating layer 22 can prevent the heating element support 10 from directly acting on the interior of the thermal field, thereby ensuring the uniformity of the thermal field temperature.

[0032] It should be noted that the inner insulation layer 21 and the outer insulation layer 22 are concentric ring structures with different diameters. The inner insulation layer 21 has a smaller diameter and is located inside the outer insulation layer 22. The difference in the inner diameter between the inner insulation layer 21 and the outer insulation layer 22 is between 20 and 500 mm, preferably between 50 and 150 mm.

[0033] It should be further noted that the materials of each component of the insulation component 2 can be graphite, carbon-carbon composite material, or carbon-ceramic composite material, with carbon-ceramic composite material being preferred. This can reduce its thermal deformation, improve mechanical strength, and increase service life. At the same time, since the surface of carbon-ceramic material is smooth, it is conducive to heat reflection, which can further improve the thermal insulation performance. The materials of each component of the heating component 1 can be graphite, carbon-carbon composite material, or carbon-ceramic composite material, with carbon-ceramic composite material being preferred. This can reduce its thermal deformation, improve mechanical strength, and increase service life.

[0034] In one embodiment, refer to Figure 2 The heating element bracket 10 includes a support portion 11 and a first connecting portion 12. The support portion 11 extends vertically and is disposed in the gap between the inner insulation layer body 21 and the outer insulation layer body 22. The first connecting portion 12 extends radially and is connected to the support portion 11 at one end, and is connected to the heating element 13 through the first opening 24 at the other end. The first connecting portion 12 connects the support portion 11 and the heating element 13. The first connecting portion 12 extends horizontally in the radial direction to avoid direct contact between the first connecting portion 12 and the heat field, thereby further ensuring the uniformity of the heat field.

[0035] It should be noted that the gap between the support part 11 and the inner insulation layer 21 and the outer insulation layer 22 can be a hollow structure or filled with soft felt, graphite or cured felt for insulation. As a preferred option, the distance between the support part 11 and the inner insulation layer 21 and the outer insulation layer 22 is set to 5 to 500 mm, which can prevent arcing and affect the safety of the thermal field.

[0036] It should be further noted that the structure of the first connecting part 12 can be a connecting plate, a connecting column, or a connecting strip, etc., and its reinforcement method can be adhesive bonding, screw fastening, or mortise and tenon structure. Regarding the size of the first connecting part 12, when the first connecting part 12 is composed of two connecting plates and a connecting column, the connecting column is set between the two connecting plates. The two connecting plates are respectively connected to the heating part 13 and the support part 11. The length of the connecting plate is between 20-1000mm, the width is between 10-1000mm, and the length of the middle connecting column is between 10-400mm. The shape is not limited.

[0037] In one embodiment, refer to Figure 1 and 2The support part 11 is arranged vertically, and a bending part 11-1 is provided at the bottom of the support part 11. The bending part 11-1 bends horizontally toward the central axis of the heat preservation component 2. The end of the bending part 11-1 is connected to the electrode. Since the bending part 11-1 bends radially inward, the stability of the support part 11 in the vertical direction can be ensured, thereby ensuring the stability of the heating part 13.

[0038] In one embodiment, refer to Figure 1 The inner insulation layer body 21 is provided with a third opening 26. The bent part 11-1 bends inward and passes through the third opening 26 to connect with the electrode. The bent part 11-1 passes through the third opening 26, so that the upper part of the support part 11 is located between the inner insulation layer body 21 and the outer insulation layer body 22, avoiding direct action on the crucible. The electrode is located outside the insulation component 2. The third opening 26 provides space for the bent part 11-1 to connect with the electrode. The connection between the electrode and the heating part 13 is realized through the heating component 1 with the bent part 11-1.

[0039] In one embodiment, the thermal insulation component 2 is divided vertically along the axial direction into an upper thermal insulation section A, a middle thermal insulation section B, and a lower thermal insulation section C, wherein, referring to... Figure 3 and Figure 5 The first opening 24 is provided on the inner insulation body 21 of the upper insulation section A, and the third opening 26 is provided on the inner insulation body 21 of the lower insulation section C. The insulation component 2 is divided into three layers along the axial direction, which can adapt to the heating component 1 with a higher height. Since the upper part of the heating bracket 10 is provided with a bending part 11-1 that bends horizontally towards the central axis of the insulation component 2, and the lower part has a first connecting part 12 that extends radially, if the insulation component 2 is a single component, the heating bracket 10 cannot be smoothly installed between the inner insulation body 21 and the outer insulation body 22. The first opening 24 is opened on the upper insulation section A, and the third opening 26 is opened on the lower insulation section C. Since the upper insulation section A and the lower insulation section C are two independent insulation components, the first opening 24 and the third opening 26 are respectively provided in two different insulation components, which facilitates the installation of the heating bracket 10 and the insulation component 2.

[0040] In one embodiment, refer to Figure 3-5The lower end of the upper insulation section A, the upper and lower ends of the middle insulation section B, and the upper end of the lower insulation section C are all provided with a second connecting part 23. The second connecting part 23 connects the inner insulation layer body 21 and the outer insulation layer body 22 at the lower end of the upper insulation section A, the upper and lower ends of the middle insulation section B, and the upper end of the lower insulation section C. The second connecting part 23 at the lower end of the upper insulation section A, the upper and lower ends of the middle insulation section B, and the upper end of the lower insulation section C are all provided with a second opening 25 through which the heating part bracket 10 passes. During installation, the support part 11 is placed in the insulation assembly 2. The support part 11 passes through the second opening 25 on the second connecting part 23 located at the lower end of the upper insulation section A, the upper and lower ends of the middle insulation section B, and the upper end of the lower insulation section C. The second opening 25 provides installation space for the support part 11.

[0041] In one embodiment, multiple heating element supports 10 are provided and evenly distributed along the circumference of the heating element 13. The inner diameter of the circle formed by the support parts 11 in the multiple heating element supports 10 is larger than the outer diameter of the heating element 13. In this embodiment, two heating element supports 10 are provided along the diameter of the heating element 13, and the distance between the two support parts 11 is larger than the outer diameter of the heating element 13, so that the support parts 11 are far away from the crucible inside the single crystal furnace relative to the heating element 13, further reducing the heat generation effect of the support parts 11. Preferably, the diameter difference between the support parts 11 and the heating element 13 is between 10 and 400 mm, and more preferably between 100 and 200 mm.

[0042] In one embodiment, both the inner and outer walls of the inner insulation layer 21 and the outer insulation layer 22 are provided with an insulation coating. The insulation coating can be a coating that can change the original insulation performance, such as silicon carbide, tantalum carbide, gallium nitride, or tungsten-molybdenum metal.

[0043] In one embodiment, refer to Figure 1 There is a gap between the heating part 13 and the inner insulation layer body 21. Preferably, the distance between the heating part 13 and the inner insulation layer body 21 is 5 to 100 mm. The distance between the heating part support 10 and the inner insulation layer body 21 and the outer insulation layer body 22 is set to be greater than 2 mm to prevent arcing and affect the safety of the thermal field.

[0044] The thermal field structure for a single crystal furnace of this invention, through the design of a heating component 1 with a special structure and a heat insulation component 2 with a double-layer body, places the support part 11 in the heating component between the inner heat insulation body 21 and the outer heat insulation body 22. Without affecting the heating part 13, it reduces the heat brought by the heater in the lower part of the thermal field, lowers the temperature in the lower part of the thermal field, which is conducive to reducing oxygen precipitation and improving crystal quality. It also eliminates the non-uniformity of thermal field temperature distribution caused by the heating of the support part 11, thereby improving the uniformity of radial temperature distribution in the thermal field, improving crystal growth conditions, and improving crystal formation quality. At the same time, after improving the uniformity of thermal field temperature, it can appropriately reduce crystal rotation and crucible rotation, further reducing the scouring effect of melt on quartz crucible, thereby reducing the oxygen precipitation from the quartz crucible and increasing its service life.

[0045] Example 2

[0046] Unlike the above embodiments, this embodiment provides a single crystal furnace. This single crystal furnace is equipped with the above-mentioned thermal field structure for the single crystal furnace. The thermal field structure for the single crystal furnace is fitted onto the outside of the crucible in the single crystal furnace. Since the heat preservation component 2 has a double-layer structure, the support part 11 in the heating component 1 is arranged between the double-layer structure of the heat preservation component 2, which avoids the support part 11 directly transferring heat to the crucible in the vertical direction, thus preventing the problem of uneven thermal field. Furthermore, after improving the uniformity of the thermal field, the single crystal furnace can appropriately reduce crystal rotation and crucible rotation, further reducing the scouring effect of the melt on the quartz crucible, thereby reducing the oxygen released from the dissolved quartz crucible, increasing its service life, and improving the quality of crystal formation.

[0047] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A thermal field structure for a single crystal furnace, characterized in that: It includes a heating component (1) and a heat preservation component (2). The heating component (1) includes a heating part bracket (10) and a heating part (13). The heat preservation component (2) includes a heat preservation inner layer body (21) and a heat preservation outer layer body (22). The heating part (13) is disposed on the inner side of the heat preservation inner layer body (21). The inner insulation layer body (21) and the outer insulation layer body (22) are both annular structures and are arranged with a radial gap between them. The inner insulation layer body (21) has a first opening (24). The heating part bracket (10) is arranged in the gap between the inner insulation layer body (21) and the outer insulation layer body (22) and one end passes through the first opening (24) and is connected to the heating part (13).

2. The thermal field structure for a single crystal furnace according to claim 1, characterized in that: The insulation component (2) further includes a second connecting part (23), which is disposed at the upper and lower ends of the inner insulation body (21) and the outer insulation body (22) and covers the gap between the inner insulation body (21) and the outer insulation body (22) radially.

3. The thermal field structure for a single crystal furnace according to claim 2, characterized in that: The heating element bracket (10) includes a support part (11) and a first connecting part (12). The support part (11) extends vertically and is disposed in the gap between the inner insulation layer body (21) and the outer insulation layer body (22). The first connecting part (12) extends radially and is connected to the support part (11) at one end and to the heating element (13) at the other end through the first opening (24).

4. The thermal field structure for a single crystal furnace according to claim 3, characterized in that: A bent portion (11-1) is provided at the bottom of the support portion (11), and the bent portion (11-1) bends inward radially.

5. A thermal field structure for a single crystal furnace according to claim 4, characterized in that: The inner insulation layer body (21) is provided with a third opening (26), and the bent part (11-1) bends inward and passes through the third opening (26) to connect with the electrode.

6. The thermal field structure for a single crystal furnace according to claim 5, characterized in that: The insulation component (2) is divided into an upper insulation section (A), a middle insulation section (B) and a lower insulation section (C) along the axial direction. The first opening (24) is provided on the inner insulation body (21) of the upper insulation section (A), and the third opening (26) is provided on the inner insulation body (21) of the lower insulation section (C).

7. The thermal field structure for a single crystal furnace according to claim 6, characterized in that: The lower end of the upper insulation section (A), the upper and lower ends of the middle insulation section (B), and the upper end of the lower insulation section (C) are all provided with the second connecting part (23), and the second connecting part (23) provided on the lower end of the upper insulation section (A), the upper and lower ends of the middle insulation section (B), and the upper end of the lower insulation section (C) are all provided with a second opening (25) through which the heating part bracket (10) passes.

8. The thermal field structure for a single crystal furnace according to claim 1, characterized in that: Multiple heating element supports (10) are provided and are evenly distributed along the circumference of the heating element (13).

9. The thermal field structure for a single crystal furnace according to claim 1, characterized in that: The inner and outer walls of the inner insulation layer (21) and the outer insulation layer (22) are both provided with insulation coatings.

10. A single crystal furnace, comprising the thermal field structure for a single crystal furnace as described in any one of claims 1 to 9.

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