Water cooling screen for monocrystalline silicon growth furnace

Abstract

The utility model provides a water cooling screen for a monocrystalline silicon growth furnace, and belongs to the field of monocrystalline silicon material production equipment. The water cooling screen comprises a liquid inlet, a liquid outlet, a far silicon liquid end part, a middle part and a near silicon liquid end part; the water cooling screen is provided with a cavity, and a flow channel is arranged in the cavity. The near silicon liquid end part comprises an inner wall, a bottom surface and an outer wall, the inner wall is vertical, and the thickness of the plate surface is gradually reduced in a gradient manner from top to bottom; the bottom surface is an inclined surface forming a preset inclination angle with the horizontal plane; and a reflecting layer / polishing layer is added on the near silicon liquid level of the bottom surface and the outer wall. According to the utility model, the reflectivity of thermal radiation of silicon liquid is increased, radiation absorption is reduced, the cooling effect of a silicon rod is improved, in addition, convective heat exchange on the outer side of the water-cooling screen is weakened, the absorption of the water-cooling screen to heat on the outer side is reduced, on one hand, the heat preservation effect of the heat screen is improved, and on the other hand, the energy consumption is reduced, so that the production cost is saved; and the production efficiency is improved.

Description

Technical Field

[0001] This utility model belongs to the field of monocrystalline silicon material production equipment, specifically relating to a water-cooled screen for monocrystalline silicon growth furnace. Background Technology

[0002] A monocrystalline silicon growth furnace is a device used to produce monocrystalline silicon rods using the direct method. It generally includes a main unit, a heating power supply, and a control system. The main unit comprises a vertical frame, a water-cooled furnace body, and a crystal lifting and rotating mechanism. In the water-cooled furnace body, polycrystalline silicon raw material is melted into liquid silicon at high temperatures. The molten silicon is then slightly cooled to create a certain degree of supercooling. A single silicon crystal (called a seed crystal), fixed to a seed crystal shaft, is inserted into the surface of the melt. After the seed crystal fuses with the melt, it is slowly pulled upwards, and the crystal grows at the lower end of the seed crystal, eventually forming a monocrystalline rod. To improve the production efficiency of monocrystalline silicon rods, the pulling speed can be increased by cooling the silicon rod while maintaining its integrity.

[0003] In existing technologies, water-cooled screens are generally used to control the temperature of molten silicon and single crystal rods, thereby improving the pulling speed and production efficiency of single crystal silicon rods. On the one hand, water-cooled screens can effectively reduce the temperature of silicon rods, thus improving production efficiency; on the other hand, when cooling silicon rods, the water-cooled screen needs to ensure that the temperature of the molten silicon is above its melting point to prevent solidification. Existing water-cooled screens generally use a horizontal annular flow channel that swirls around the furnace body. The sides of the annular flow channel are covered with a material of fixed thickness to form a closed flow channel, allowing cooling water to flow from bottom to top, thereby cooling the silicon rods inside the furnace. However, ordinary covering materials of fixed thickness do not consider the thermal field details of specific application scenarios, resulting in low cooling efficiency and insufficient insulation of the molten silicon. 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 silicon growth furnace. By redesigning the thickness of the inner cladding layer at the lower end of the water-cooled screen, and adding a reflective layer or polished layer to the bottom and outer cladding layers, the reflectivity of the silicon melt thermal radiation is increased, radiation absorption is reduced, and the cooling effect on the silicon rod is improved. In addition, the convective heat transfer on the outer side of the water-cooled screen is weakened, thereby reducing the absorption of heat by the water-cooled screen on the outer side. On the one hand, the heat preservation effect of the screen is improved, and on the other hand, energy consumption is reduced, thereby saving production costs and improving production efficiency.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A water-cooled screen for a single-crystal silicon growth furnace includes: a liquid inlet 21, a liquid outlet 22, a far-silicon liquid end 23, a middle section 24, and a near-silicon liquid end 25; the water-cooled screen 20 has a cavity 250, and the cavity has a flow channel inside;

[0007] The near-silicon liquid end 25 includes an inner wall 251, a bottom surface 253, and an outer wall 252. The inner wall 251 is vertical, and the thickness of the plate decreases gradually from top to bottom. The bottom surface 253 is an inclined surface with a preset angle of 10-60° to the horizontal plane, and the inclined surface forms an acute angle with the inner wall 251.

[0008] In a preferred embodiment of this utility model, the preset inclination angle of the inclined plane is 10-60°.

[0009] In a preferred embodiment of the present invention, a reflective / polished layer 255 is added to the near-silicon liquid surface of the bottom surface 253.

[0010] In a preferred embodiment of this utility model, the outer wall 252, which is connected to the bottom surface, is provided with an outer wall reflective layer / polishing layer 254.

[0011] In a preferred embodiment of this utility model, the thickness of the lower end of the inner wall that connects with the bottom surface is 40%-80% of the thickness of the upper end.

[0012] The technical solution provided by this utility model embodiment has the following beneficial effects:

[0013] The water-cooled screen for a single-crystal silicon growth furnace provided in this embodiment includes an inlet 21, an outlet 22, a far-silicon liquid end 23, a middle section 24, and a near-silicon liquid end 25. The water-cooled screen 20 has a cavity 250, and the cavity has a flow channel inside. The near-silicon liquid end 25 includes an inner wall 251, a bottom surface 253, and an outer wall 252. The inner wall 251 is vertical, and the thickness of the plate surface decreases gradually from top to bottom. The bottom surface 253 is an inclined surface with a preset angle to the horizontal plane. The near-silicon liquid surface of the bottom surface 253 and the outer wall 252 are provided with a reflective layer / polishing layer 255 / 254. This invention increases the reflectivity of the silicon liquid's thermal radiation, reduces radiation absorption, and improves the cooling effect on the silicon rod. In addition, it weakens the convective heat transfer on the outside of the water-cooled screen, thereby reducing the absorption of heat from the outside by the water-cooled screen. On the one hand, it improves the heat preservation effect of the heat shield, and on the other hand, it reduces energy consumption, thus saving production costs and improving production efficiency.

[0014] Of course, implementing any product or method of this utility model does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of the single crystal silicon growth furnace and water-cooled screen described in this embodiment of the utility model;

[0017] Figure 2 This is an embodiment of the present utility model. Figure 1 Enlarged view of part A in the image.

[0018] Explanation of reference numerals in the attached figures:

[0019] 10-Single crystal furnace; 20-Water-cooled screen; 21-Liquid inlet; 22-Liquid outlet; 23-Far silicon liquid end; 24-Middle of water-cooled screen; 25-Near silicon liquid end; 250-Water-cooled screen cavity; 251-Inner wall; 252-Outer wall; 253-Bottom surface; 254-Outer wall reflective layer / polishing layer; 255-Bottom surface reflective layer / polishing layer; 30-Heat shield; 40-Single crystal silicon rod; 50-Silicon liquid; 60-Crucible. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. The components of the embodiments of the present utility model 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 utility model 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 utility model, 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] like Figure 1 and Figure 2As shown, this embodiment of the present invention provides a water-cooled screen for a single-crystal silicon growth furnace. In this embodiment, the single-crystal silicon growth furnace includes a cylindrical single-crystal furnace body 10, a crucible 60, a heat shield 30, and a water-cooled screen 20. The crucible 60, the heat shield 30, and the water-cooled screen 20 are arranged sequentially from the outside to the inside of the furnace body, and all of them are rotating bodies. The water-cooled screen 20 includes: a liquid inlet 21, a liquid outlet 22, a far-silicon liquid end 23, a middle part 24, and a near-silicon liquid end 25; the water-cooled screen 20 has a water-cooled screen cavity 250, and the cavity has a flow channel, so that the water flowing in from the liquid inlet 21 flows along the flow channel in a predetermined manner and flows out to the liquid outlet 22.

[0023] The end 25 near the molten silicon includes an inner wall 251, a bottom surface 253, and an outer wall 252. The inner wall 251 is vertical, and the thickness of the plate decreases gradually from top to bottom to enhance heat exchange between the coolant and the solid-liquid surface within the water-cooled screen. In a preferred embodiment, the thickness of the lower end of the plate is 30%-50% of the thickness of the upper end. The bottom surface 253 is an inclined plane with a preset angle of 0-60° to the horizontal plane, forming an acute angle with the inner wall 251. A bottom reflective layer / polished layer 255 is added to the near-molten silicon surface of the bottom surface 253 to increase the reflectivity of the molten silicon's thermal radiation and reduce radiation absorption. The outer wall 252, which connects to the bottom surface, is further reinforced with an outer reflective layer / polished layer 254. Through the above configuration, the growth rate of the single-crystal silicon rod is improved, and the yield of the silicon rod is increased simultaneously while increasing the cooling rate.

[0024] When the water-cooled screen 20 is applied to the monocrystalline silicon growth furnace 10 to produce monocrystalline silicon rods 40, the rods 40 are arranged inside the furnace. The water-cooled screen 20 uses the liquid flowing in the water-cooled screen cavity 250 to cool the rods 40. The bottom surface 253 of the water-cooled screen 20 is adjacent to the silicon liquid 50 and acts as an insulation layer, providing insulation for the silicon liquid. The surface of the silicon liquid 50 emits thermal radiation. Due to the inward tilt angle of the bottom surface 253 of the water-cooled screen, the absorption of radiation on the surface of the silicon liquid 50 is reduced, while the amount of thermal radiation reflected back to the silicon liquid 50 is also reduced. At the same time, the addition of a reflective / polished layer 255 / 254 to the bottom surface 253 and the outer wall 252 of the water-cooled screen weakens the convective heat transfer on the outside of the water-cooled screen, thereby reducing the absorption of heat from the outside by the water-cooled screen. This improves the insulation effect of the screen and reduces energy consumption. Furthermore, the tapered shape of the inner wall reduces thermal resistance, enhances the heat dissipation of the silicon rod, and effectively increases the growth rate of the silicon rod.

[0025] The above description is merely a preferred embodiment of the present utility model and an explanation of the technical principles employed, and is not intended to limit the scope of the claimed utility model, but merely to illustrate preferred embodiments of the present utility model. Those skilled in the art should understand that the scope of the present utility model is not limited to the specific combination of the above-described technical features, but should also cover other technical solutions formed by any combination 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 utility model without inventive effort are within the scope of protection of the present utility model.

Claims

1. A water-cooled screen for a single-crystal silicon growth furnace, comprising: The water-cooled screen (20) includes an inlet (21), an outlet (22), a distal end (23), a middle section (24), and a proximal end (25); the water-cooled screen (20) has a cavity (250) with flow channels inside; its characteristic is that... The near-silicon liquid end (25) includes an inner wall (251), a bottom surface (253) and an outer wall (252). The inner wall (251) is vertical, and the thickness of the plate decreases gradually from top to bottom. The bottom surface (253) is an inclined surface with a preset angle to the horizontal plane, and the inclined surface forms an acute angle with the inner wall (251).

2. The water-cooled screen for a single-crystal silicon growth furnace according to claim 1, characterized in that, The preset inclination angle of the inclined plane is 10-60°.

3. The water-cooled screen for a single-crystal silicon growth furnace according to claim 1, characterized in that, The bottom surface (253) near the silicon liquid surface is enhanced with a bottom reflective layer / polishing layer (255).

4. The water-cooled screen for a single-crystal silicon growth furnace according to claim 1, characterized in that, The outer wall (252) that connects to the bottom surface is reinforced with a reflective / polished layer (254).

5. The water-cooled screen for a single-crystal silicon growth furnace according to any one of claims 1-4, characterized in that, The inner wall (251) that connects to the bottom surface has a thickness of 40%-80% of the thickness of the upper surface at the lower end.

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