Single crystal furnace water cooling screen with high heat absorption efficiency

Abstract

The invention provides a single crystal furnace water cooling screen with high heat absorption efficiency, and belongs to the field of single crystal production equipment. Fins are arranged on the inner wall of the water cooling screen; fins are arranged on the inner wall; the fins intersect with the surface of the inner wall and form a preset angle, annular or spiral platforms which extend inwards and are parallel to one another are formed on the surface of the inner wall, and light trapping structures are formed between the platforms. The preset angle is smaller than or equal to 90 degrees; when the fins are continuous fins, the fins are welded or bonded on the inner wall in a parallel annular or spiral manner; when the fins are breakpoint fins, a plurality of broken single fins form a ring with spaced openings on the inner wall, the arc length of the single fin between every two openings is 1 / 10-1 / 4 of the diameter of the inner wall of the water cooling screen, and the lengths are the same or different; the arc length of the opening at the breakpoint is not larger than 50%-100% of the arc length of the adjacent shortest fin. The heat absorption efficiency of the water cooling screen is improved.

Description

Technical Field

[0001] This invention belongs to the field of single crystal production equipment, specifically relating to a water-cooled screen for a single crystal furnace with high heat absorption efficiency. Background Technology

[0002] Single crystals, as a form of solid existence, are crystalline structures with a regular and periodic arrangement of particles in three-dimensional space. The arrangement of particles within the crystal exhibits long-range order and unique properties such as symmetry, anisotropy, and a fixed melting point, making them widely used in electromagnetism, semiconductors, optics, and photovoltaics. Common examples include single-crystal silicon, quartz single crystals, and garnet single crystals. Single crystals can be naturally occurring or artificially synthesized. Artificial preparation methods include vapor phase growth, solution growth, hydrothermal growth, molten salt methods, and melt methods. The most common techniques include the Czochralski method, crucible lowering method, zone melting method, and directional solidification method. The growth quality of a crystal directly determines its performance and further affects the quality of the fabricated devices. For example, single-crystal silicon, as a core material in the semiconductor and photovoltaic industries, directly impacts the performance of photovoltaic devices. The Czochralski method is currently the mainstream technology for single-crystal preparation. Its core equipment, the single-crystal furnace, achieves crystal growth by controlling parameters such as the thermal field and airflow. Inside the single-crystal furnace, the water-cooled screen, as a key component, serves a dual function of heat dissipation and airflow conduction.

[0003] In existing technologies, water-cooled screens typically employ a smooth inner wall design. While this structure is simple to manufacture, it has certain limitations in actual operation. The heat absorption efficiency of the water-cooled screen affects the cooling rate of the single crystal rod, which is closely related to the production cycle of the single crystal rod. The heat absorption efficiency of a smooth inner wall generally depends only on the material itself and cannot improve heat absorption from a structural perspective, resulting in low heat absorption efficiency. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, the present invention aims to provide a water-cooled screen for a single crystal furnace with high heat absorption efficiency. By adding a spiral fin structure with light-trapping effect to the inner wall of the water-cooled screen, the radiation absorption area of ​​the water-cooled screen is increased. At the same time, the spiral structure enhances the disturbance of airflow and improves the overall stability of airflow, thereby improving the heat absorption efficiency of the water-cooled screen, increasing the pulling speed of single crystal silicon, and reducing oxygen content.

[0005] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions: In a first aspect, embodiments of the present invention provide a water-cooled screen for a single crystal furnace with high heat absorption efficiency. The water-cooled screen includes a liquid inlet, a liquid outlet, an outer wall, and an inner wall, with fins provided on the inner wall. The fins intersect with the surface of the inner wall at a predetermined angle, forming inwardly extending, parallel, annular or spiral platforms on the surface of the inner wall, with light-trapping structures formed between the platforms.

[0006] In a preferred embodiment of the present invention, the predetermined angle formed between the fins and the inner wall surface is less than or equal to 90 degrees.

[0007] In a preferred embodiment of the present invention, the length of the fin extending toward the axis of the water-cooled screen is 5-20 mm and the thickness is 1-6 mm; the fin and the inner wall are fixedly connected by bonding or welding at the perpendicular intersection, and the distance between two adjacent intersection lines is 2-10 times the thickness of the fin.

[0008] In a preferred embodiment of the present invention, the fins are continuous fins or discontinuous fins.

[0009] In a preferred embodiment of the present invention, the fins are continuous fins, which are welded or bonded to the inner wall in a parallel annular or spiral manner, and the free ends of the fins extend into the interior of the water-cooled screen.

[0010] In a preferred embodiment of the present invention, the fin is a discontinuous fin, and several discontinuous individual fins form an annular ring with spaced openings on the inner wall.

[0011] In a preferred embodiment of the present invention, the arc length of a single fin between every two openings of the breakpoint fin is 1 / 10 to 1 / 4 of the inner wall diameter of the water-cooled screen, and the lengths may be the same or different; the arc length of the opening at the breakpoint is not greater than 50% to 100% of the arc length of the adjacent shortest fin.

[0012] In a preferred embodiment of the present invention, the upper and / or lower surfaces of the fins are provided with microgrooves.

[0013] In a preferred embodiment of the present invention, the fins are made of a metal material with good thermal conductivity.

[0014] Secondly, embodiments of the present invention also provide a method for improving the heat absorption efficiency of a water-cooled screen in a single crystal furnace, wherein fins are provided on the inner wall of the water-cooled screen; the fins intersect with the surface of the inner wall at a predetermined angle, and inwardly extending, parallel, annular or spiral platforms are formed on the surface of the inner wall, with light-trapping structures formed between the platforms.

[0015] The technical solutions provided in the embodiments of the present invention have the following beneficial effects: The single-crystal furnace water-cooled screen with high heat absorption efficiency provided in this embodiment of the invention forms a light-trapping structure to a certain extent by setting densely distributed fins on the inner wall, which increases the surface area for convection with the airflow and further increases the effective heat transfer area for thermal radiation, thereby improving the heat absorption capacity of the water-cooled screen for the silicon rod. The pre-defined openings between adjacent fins in the breakpoint fin structure prevent damage to the fin structure due to thermal expansion and contraction. The multi-layered fins are in direct contact with the airflow, increasing the convective heat transfer area and heat transfer time between the airflow and the water-cooled screen. Simultaneously, the fin structure is located in the airflow path, which can disturb the airflow, disrupt the boundary layer, increase the heat transfer coefficient between the airflow and the wall, and enhance the heat transfer effect between the water-cooled screen and the airflow. The increased airflow fluctuations also enhance the mass transfer effect, improve the O2 removal efficiency, and prevent its local accumulation on the melt surface, reducing the oxygen content in the single crystal from the airflow control level and improving the quality of the single crystal silicon. The inclined structure of the fins increases the absorption of heat from below, strengthens the heat transfer at the solid-liquid interface, and increases the crystal pulling rate.

[0016] Of course, implementing any product or method of the present invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the installation of a water-cooled screen for a single crystal furnace with high heat absorption efficiency, as described in an embodiment of the present invention. Figure 2 This is a schematic diagram of the single-crystal furnace water-cooled screen structure with high heat absorption efficiency as described in an embodiment of the present invention; Figure 3 This is a schematic diagram of the multi-layer continuous fin integrated structure in the water-cooled screen according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the multi-layered breakpoint fin integrated structure in the water-cooled screen according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the tilt angle structure of the fins described in an embodiment of the present invention; Figure 6 This is a schematic diagram of the microgroove structure of the fins described in an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures: 1-Single crystal furnace body; 2-Single crystal rod; 3-Molten liquid; 4-Water-cooled screen; 41-Outer wall; 42-Inner wall; 43-Fin; 431-Annular fin; 432-Breakpoint fin; 433-Breakpoint fin opening. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can also be combined with each other.

[0021] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, the terms "first," "second," "third," "fourth," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] To address the issues of insufficient heat exchange between the inner wall of the water-cooled screen and the single crystal rod, and the difficulty in reducing the oxygen content of the single crystal rod in existing single crystal furnaces, which lead to decreased crystal quality and production efficiency, this invention provides a single crystal furnace water-cooled screen with high heat absorption efficiency. The inner surface of the water-cooled screen is equipped with a light-trapping fin structure, increasing the radiation absorption area of ​​the screen and enhancing the disturbance of argon gas, thereby improving the overall stability of the airflow. Simultaneously, it improves the heat absorption effect of the water-cooled screen and argon gas on the silicon rod, increasing the heat absorption efficiency of the water-cooled screen, thereby increasing the pulling speed of single crystal silicon and reducing the oxygen content.

[0023] like Figure 1 As shown in the embodiment of the present invention, the single crystal furnace water-cooled screen with high heat absorption efficiency is installed in the single crystal furnace. The basic structure of the single crystal furnace includes: furnace body 1, molten liquid 3, single crystal rod 2, and water-cooled screen 4 disposed above the molten liquid 3 and outside the single crystal rod 2.

[0024] like Figure 2 As shown, the water-cooled screen 4 includes an outer wall 41 and an inner wall 42, with fins 43 disposed on the inner wall 42. The fins 43 include continuous fins and discontinuous fins, which are continuous sheet structures and discontinuous sheet structures, respectively. They intersect with the surface of the inner wall 42, forming an inwardly extending annular platform on the surface of the inner wall 42. The outward extension length L of the platform is 5~20mm, and the thickness H is 1~6mm. The fins are fixedly connected to the inner wall at the intersection by bonding or welding. The distance between two adjacent intersection lines... d The thickness is 2 to 10 times that of the fins to ensure the carrying capacity for airflow; at the same time, a close-packed structure of the fins is formed to ensure the trapping effect.

[0025] like Figure 3As shown, when the fin 43 is a continuous fin 431, it is welded or bonded to the inner wall 42 in a parallel or spiral manner, and the free end of the fin extends into the interior of the water-cooled screen.

[0026] like Figure 4 As shown, when fin 43 is a discontinuous fin 432, several discontinuous individual fins form an annular ring with spaced openings 433 on the inner wall. This prevents internal stress from thermal expansion and contraction, reduces damage to the fin structure caused by thermal expansion and contraction, and helps guide gas to flow more evenly throughout the heat exchange zone, reducing dead zones and fully utilizing the heat exchange area. The arc length between each pair of openings 433 and the inner wall is 1 / 10 to 1 / 4 of the inner wall diameter of the water-cooled screen, and the lengths may be the same or different. The arc length of the opening 433 at the discontinuity is no greater than 50% to 100% of the arc length of the adjacent shortest fin. In a preferred embodiment, the arc length of a single fin is greater than 10 mm and less than 80 mm, and the adjacent spacing, i.e., the distance between openings, is less than 10 mm.

[0027] like Figure 5 As shown, preferably, the fins 43 intersect with the surface of the inner wall 42 to form a predetermined angle. α The predetermined angle α Less than or equal to 90 degrees. This limitation on the predetermined angle does not mean that only angles less than 90 degrees can be selected. The fin design can intersect the surface to form any angle or be directly parallel to the horizontal plane. However, considering the effect on airflow and heat transfer, an acute angle less than 90 degrees is preferred. Compared to fin structures parallel to the horizontal plane, the predetermined angle... α When the temperature is below 90 degrees, the obstruction, deflection and friction of the fins on the airflow will be reduced. At the same time, this design can enhance the absorption of heat radiation from the area above the water-cooled screen to the area below the silicon rod, increase the heat exchange temperature difference, and thus enhance heat exchange.

[0028] like Figure 6 As shown, the surface of the fin 43 is provided with a microgroove structure. Micro-nano structural processing of the fin surface to create fine microgrooves increases the surface roughness, which helps to disrupt the symmetry and stability of the flow, enhancing the turbulent effect of argon gas. Furthermore, it can also form micro-light-trapping structures, increasing the absorption rate of the thermal field and the thermal radiation from the silicon rod, thereby increasing heat transfer. Preferably, the microgrooves are alternating T-shaped grooves.

[0029] In this embodiment, the fins 43 form parallel platforms extending into the cavity of the water-cooled screen 4. The gaps between the fins 43 create a light-trapping structure, thereby producing a light-trapping effect. This alters the reflection and refractive index of the material surface to thermal radiation, causing the incident thermal radiation to undergo multiple reflections and scatterings within the structure. This increases the thermal radiation path length and internal reflectivity, reduces the initial reflection loss of the incident thermal radiation, and thus enhances the absorption rate of the water-cooled screen to thermal radiation. In a specific application example, the absorptivity of the inner wall of the water-cooled screen without fins is between 0.2 and 0.3. After adding discontinuous fins with an arc length of at least 10 mm, the improved absorptivity increases by 100%-200%, enhancing the heat exchange effect.

[0030] Meanwhile, as an extension of the inner wall, fin 43 increases the surface area for convection with internal airflows such as argon, thereby further increasing the effective heat exchange area with thermal radiation. In addition, fin 43 is located in the airflow path, which can enhance the disturbance effect on gas flow, disrupt the development of its boundary layer, increase the turbulence of the fluid, improve the local convective heat transfer coefficient, and prolong the actual flow time of gas inside the furnace body, allowing gas microparticles more time to exchange heat with the inner wall of the water-cooled screen and the silicon rod, which helps to increase the total heat exchange. The increased fluctuation of argon can also enhance the mass transfer effect, improve the O2 volatilization efficiency and avoid its local accumulation on the melt surface, thereby reducing the oxygen content doping level in the single crystal from the perspective of airflow control.

[0031] As can be seen from the above technical solutions, the single-crystal furnace water-cooled screen with high heat absorption efficiency provided by the embodiments of the present invention forms a light-trapping structure to a certain extent by setting densely distributed fins on the inner wall, which increases the surface area for convection with the airflow, further increases the effective heat transfer area for thermal radiation, and improves the heat absorption capacity of the water-cooled screen for silicon rods; the pre-defined openings between adjacent fins in the breakpoint fin structure can prevent the thermal expansion and contraction phenomenon from damaging the fin structure; the multi-layer fins are in direct contact with the airflow, increasing the convective heat transfer area and heat transfer time between the airflow and the water-cooled screen; at the same time, the fin structure is in the airflow path, which can disturb the airflow, destroy the boundary layer, improve the heat transfer coefficient between the airflow and the wall, and enhance the heat transfer effect between the water-cooled screen and the airflow; the increased airflow fluctuation can also enhance the mass transfer effect, improve the SiO volatilization efficiency and avoid its local accumulation on the melt surface, reduce the oxygen content doping level in the single crystal from the airflow control level, and improve the quality of single-crystal silicon; the fins are inclined structures, which can increase the absorption of heat below, enhance the heat transfer at the solid-liquid interface, and improve the crystal pulling rate.

[0032] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed, and is not intended to limit the scope of the claimed invention, but merely to illustrate preferred embodiments of the invention. Those skilled in the art should understand that the scope of the invention is not limited to the specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A water-cooled screen for a single-crystal furnace with high heat absorption efficiency, the water-cooled screen comprising a liquid inlet, a liquid outlet, an outer wall, and an inner wall, characterized in that, Fins are provided on the inner wall; The fins intersect with the surface of the inner wall at a predetermined angle, forming inwardly extending, parallel, annular or spiral platforms on the surface of the inner wall, with light-trapping structures formed between the platforms.

2. The single-crystal furnace water-cooled screen with high heat absorption efficiency according to claim 1, characterized in that, The predetermined angle formed between the fins and the inner wall surface is less than or equal to 90 degrees.

3. The single-crystal furnace water-cooled screen with high heat absorption efficiency according to claim 1, characterized in that, The fins extend 5-20 mm in length and 1-6 mm in thickness towards the axis of the water-cooled screen. The fins are fixedly connected to the inner wall at the perpendicular intersection by bonding or welding, and the distance between two adjacent intersection lines is 2-10 times the thickness of the fins.

4. The single-crystal furnace water-cooled screen with high heat absorption efficiency according to claim 1, characterized in that, The fins are either continuous fins or discontinuous fins.

5. The single-crystal furnace water-cooled screen with high heat absorption efficiency according to claim 4, characterized in that, The fins are continuous fins, welded or bonded to the inner wall in a parallel annular or spiral manner, with the free ends of the fins extending into the interior of the water-cooled screen.

6. The single-crystal furnace water-cooled screen with high heat absorption efficiency according to claim 4, characterized in that, The fins are discontinuous fins, with several discontinuous individual fins forming a ring with spaced openings on the inner wall.

7. The single-crystal furnace water-cooled screen with high heat absorption efficiency according to claim 6, characterized in that, The arc length of a single fin between every two openings of the breakpoint fin is 1 / 10 to 1 / 4 of the inner diameter of the water-cooled screen, and the lengths may be the same or different; the arc length of the opening at the breakpoint is not greater than 50% to 100% of the arc length of the adjacent shortest fin.

8. The single-crystal furnace water-cooled screen with high heat absorption efficiency according to claim 1, characterized in that, The upper and / or lower surfaces of the fins are provided with microgrooves.

9. The single-crystal furnace water-cooled screen with high heat absorption efficiency according to claim 1, characterized in that, The fins are made of a metal material with good thermal conductivity.

10. A method for improving the heat absorption efficiency of a water-cooled screen in a single crystal furnace, characterized in that, Fins are arranged on the inner wall of the water-cooled screen; the fins intersect with the surface of the inner wall at a predetermined angle, forming inwardly extending, parallel, annular or spiral platforms on the surface of the inner wall, and light trapping structures are formed between the platforms.

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