Water cooling screen and single crystal furnace

Abstract

The utility model discloses a water cooling screen and a single crystal furnace. In the water cooling screen, an annular cooling water channel is formed in the body, and the water inlet channel and the water outlet channel are both communicated with the annular cooling water channel of the body; an annular cooling water channel is formed in the additional cooling cavity; the water inlet channel and the water outlet channel are also communicated with the annular cooling water channel of the additional cooling cavity; the additional cooling cavity and the body extend in the same direction, a bottom opening of the additional cooling cavity is located above a top opening of the body, and the outer diameter of the additional cooling cavity is smaller than the inner diameter of the top of the body. The cooling effect of the water cooling screen is improved, and the equal-diameter growth rate of the single crystal furnace is improved.

Description

Technical Field

[0001] This utility model relates to a water-cooled screen and a single-crystal furnace. Background Technology

[0002] The rapid development of the solar photovoltaic industry has placed increasingly higher demands on the quality of monocrystalline cells. Companies need to continuously innovate technologically to improve the quality and yield of monocrystalline cells and reduce production costs to maximize economic benefits. Water-cooled screens, as standard auxiliary devices in monocrystalline furnaces, are fixed to the furnace cover and cannot be moved. When the crystal rod enters the water-cooled screen, the longitudinal temperature gradient of the rod increases, accelerating the cooling rate and thus speeding up the crystal pulling process and increasing production capacity. Czochralski crystal furnaces are equipped with water-cooled screens to create a uniform thermal field within the furnace. Under current equipment and process conditions, the pulling speed has reached the limit for monocrystalline growth. Forcibly increasing the pulling speed by modifying the standard operating procedure (SOP) would undoubtedly increase the risk of crystal breakage and hinder capacity improvement. To increase the pulling speed, existing equipment needs to be optimized to provide a greater temperature gradient. Meanwhile, a CCD camera is installed on top of the single crystal furnace to capture the diameter of the crystal rod, the liquid outlet distance, and the liquid surface temperature. To meet the requirements of the CCD camera's field of view for capturing the crystal rod, the height of the water-cooled screen is limited, resulting in limited heat removal from the crystal rod surface and poor cooling effect, thus restricting the crystal rod growth rate. Therefore, how to improve the cooling effect of the water-cooled screen structure, increase the crystal rod growth rate, increase the yield per unit, and reduce the cost of single crystal pulling are technical problems that need to be solved by those skilled in the art. Utility Model Content

[0003] This invention provides a water-cooled screen and a single-crystal furnace to improve the cooling effect of the water-cooled screen structure, increase the growth rate of crystal rods, increase the yield per unit, and reduce the cost of single-crystal pulling.

[0004] This utility model provides the following technical solution: a water-cooled screen, comprising a cylindrical body, a cylindrical additional cooling cavity, an inlet water channel, and an outlet water channel;

[0005] An annular cooling water channel is formed within the main body, and both the inlet water channel and the outlet water channel are connected to the annular cooling water channel of the main body.

[0006] An annular cooling water channel is formed within the additional cooling cavity, and both the inlet water channel and the outlet water channel are connected to the annular cooling water channel of the additional cooling cavity.

[0007] The additional cooling cavity extends in the same direction as the main body, the bottom opening of the additional cooling cavity is located above the top opening of the main body, and the outer diameter of the additional cooling cavity is smaller than the inner diameter of the top of the main body.

[0008] Cooling water flows simultaneously into both the main body and the auxiliary cooling chamber from the inlet channel, increasing the cooling area and allowing for faster cooling of the crystal rods during the constant-diameter growth stage. The auxiliary cooling chamber is relatively small, allowing for structural modifications only to the water-cooling screen without altering the rest of the single-crystal furnace, thus reducing the cost and difficulty of modifying existing equipment.

[0009] In some embodiments, the inner circumferential surface of the additional cooling cavity defines a cylindrical internal space. This cylindrical internal space is used for the passage of the crystal rod.

[0010] In some embodiments, the additional cooling cavity and the main body are coaxial. The central axes of the internal spaces defined by both the additional cooling cavity and the main body are the same straight line.

[0011] In some embodiments, the water inlet channel includes a water inlet pipe, a first water inlet branch pipe connected to the end of the water inlet pipe, and a second water inlet branch pipe connected to the end of the water inlet pipe. The end of the first water inlet branch pipe is connected to the lower outer periphery of the additional cooling cavity, and the end of the second water inlet branch pipe is connected to the top of the main body.

[0012] Specifically, a through hole is opened at the lower outer periphery of the additional cooling cavity, and the end of the first water inlet branch pipe is connected to the through hole.

[0013] With this design, cooling water flows in from the inlet pipe and then splits, flowing into the auxiliary cooling chamber via the first inlet branch pipe and into the main body via the second inlet branch pipe.

[0014] In some embodiments, the water outlet channel includes a water outlet pipe, a first water outlet branch pipe connected to the beginning of the water outlet pipe, and a second water outlet branch pipe connected to the beginning of the water outlet pipe. The beginning of the first water outlet branch pipe is connected to the lower outer periphery of the additional cooling cavity, and the beginning of the second water outlet branch pipe is connected to the top of the main body.

[0015] Specifically, a through hole is opened on the lower outer periphery of the additional cooling cavity, and the beginning of the first water outlet branch pipe is connected to the through hole.

[0016] With this design, the heated cooling water flows into the outlet pipe through the first outlet branch pipe and into the outlet pipe through the second outlet branch pipe.

[0017] The first inlet branch pipe and the first outlet branch pipe also serve to fix the additional cooling cavity relative to the main body.

[0018] In some embodiments, the axial dimension of the additional cooling cavity is in the range of 270 mm to 330 mm.

[0019] If the axial dimension (height in the operating state) of the additional cooling cavity is too large, it can easily cause structural interference and obstruct the image sensor's view. If the dimension is too small, the effect of accelerating cooling and increasing the temperature gradient is limited.

[0020] In some embodiments, the inner diameter of the additional cooling cavity is in the range of 330 mm to 350 mm.

[0021] If the inner diameter of the additional cooling cavity is too small, it is prone to interference with the crystal rod structure. If the size is too large, the cooling effect on the crystal rod will be poor.

[0022] In some embodiments, the outer diameter of the additional cooling cavity is in the range of 385 mm to 405 mm.

[0023] If the outer diameter of the auxiliary cooling cavity is too large, it may obstruct the view of the graphics sensor. If the size is too small, the fluid space inside the auxiliary cooling cavity will be limited, resulting in poor cooling effect on the crystal ingot.

[0024] In some embodiments, the axial distance between the top of the additional cooling cavity and the bottom of the body is in the range of 900 mm to 1100 mm.

[0025] If the height of the additional cooling chamber and the main body is too large, it may interfere with the existing component structure inside the single crystal furnace. If the size is too small, it will result in a small field of view of the image sensor or limited improvement in cooling effect.

[0026] The above-mentioned size range of additional cooling chambers is applicable to conventional single crystal furnaces.

[0027] It should be noted that this utility model does not limit the structural design of the main body, and any known structural design scheme of the water-cooled screen main body can be adopted.

[0028] This utility model provides the following technical solution: a single crystal furnace, including the above-mentioned water-cooled screen, wherein the water-cooled screen can be moved up and down in a controlled manner;

[0029] It also includes a crucible disposed below the body of the water-cooled screen and an image sensor disposed above the crucible;

[0030] When the water-cooled screen is at any working height, the image sensor can observe the area in the opening of the crucible that is opposite to the bottom opening of the body of the water-cooled screen through the gap between the bottom outer periphery of the additional cooling cavity and the top inner periphery of the main body.

[0031] With this design, the image sensor can observe the liquid surface of the semiconductor liquid and the solid-liquid critical interface of the semiconductor.

[0032] The water-cooled screen and single-crystal furnace of this invention provide excellent cooling and a large temperature gradient for semiconductor single-crystal rods, effectively increasing the growth rate of the rods during the constant-diameter growth stage. Further equipment modifications are low-cost and easy to implement. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the water-cooled screen structure according to an embodiment of the present invention.

[0034] Figure 2 This is a schematic diagram of the structure of the water-cooled screen of the single crystal furnace during material feeding, according to an embodiment of this utility model.

[0035] Figure 3 This is a schematic diagram of the structure of the water-cooled screen of the single crystal furnace during crystal pulling, according to an embodiment of this utility model.

[0036] The attached figures are labeled as follows: 11, water inlet pipe; 12, first water inlet branch pipe; 13, second water inlet branch pipe; 2, main body; 3, auxiliary cooling chamber; 41, water outlet pipe; 42, first water outlet branch pipe; 43, second water outlet branch pipe; 200, crystal rod; 201, liquid semiconductor; 300, image sensor; 400, furnace cover; 500, main heater; 600, furnace cylinder; 700, crucible. Detailed Implementation

[0037] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0038] Example 1

[0039] Figure 1 This is a schematic diagram of the water-cooled screen structure according to an embodiment of the present invention. Figure 2 and Figure 3 This demonstrates the application of a water-cooled screen within a single-crystal furnace.

[0040] refer to Figure 1 Example 1 provides a water-cooled screen, including a cylindrical body 2, a cylindrical additional cooling cavity 3, an inlet water channel and an outlet water channel;

[0041] A ring-shaped cooling water channel is formed inside the main body 2, and the inlet water channel and the outlet water channel are both connected to the ring-shaped cooling water channel of the main body 2.

[0042] An annular cooling water channel is formed inside the auxiliary cooling cavity 3, and the inlet water channel and the outlet water channel are also connected to the annular cooling water channel of the auxiliary cooling cavity 3.

[0043] The auxiliary cooling cavity 3 and the main body 2 extend in the same direction. The bottom opening of the auxiliary cooling cavity 3 is located above the top opening of the main body 2. The outer diameter of the auxiliary cooling cavity 3 is smaller than the inner diameter of the top of the main body 2.

[0044] refer to Figure 3 Cooling water flows simultaneously into the main body 2 and the auxiliary cooling chamber 3 from the inlet channel, increasing the cooling area and allowing for faster cooling of the crystal rod 200 during the constant diameter growth stage. The auxiliary cooling chamber 3 is relatively small in size, allowing for structural modifications only to the water-cooling screen without altering the rest of the single crystal furnace equipment, thus reducing the cost and difficulty of modifying existing single crystal furnace equipment.

[0045] Specifically, the inner circumferential surface of the supplementary cooling cavity 3 defines a cylindrical internal space. This cylindrical internal space is used for the crystal rod 200 to pass through. The inner diameter of the supplementary cooling cavity 3 is equal to the inner diameter of the bottom of the main body 2.

[0046] Specifically, the auxiliary cooling chamber 3 and the main body 2 are coaxial. The central axes of the internal spaces defined by the auxiliary cooling chamber 3 and the main body 2 are the same straight line.

[0047] Specifically, the water inlet channel includes a water inlet pipe 11, a first water inlet branch pipe 12 connected to the end of the water inlet pipe 11, and a second water inlet branch pipe 13 connected to the end of the water inlet pipe 11. The end of the first water inlet branch pipe 12 is connected to the lower outer periphery of the auxiliary cooling cavity 3, and the end of the second water inlet branch pipe 13 is connected to the top of the main body 2.

[0048] With this design, cooling water flows in from the inlet pipe 11 and then splits into two streams: one flows into the auxiliary cooling chamber 3 via the first inlet branch pipe 12, and the other flows into the main body 2 via the second inlet branch pipe 13.

[0049] Specifically, the water outlet channel includes a water outlet pipe 41, a first water outlet branch pipe 42 connected to the beginning of the water outlet pipe 41, and a second water outlet branch pipe 43 connected to the beginning of the water outlet pipe 41. The beginning of the first water outlet branch pipe 42 is connected to the lower outer periphery of the auxiliary cooling cavity 3, and the beginning of the second water outlet branch pipe 43 is connected to the top of the main body 2.

[0050] With this design, the heated cooling water flows into the outlet pipe 41 through the first outlet branch pipe 42 and into the outlet pipe 41 through the second outlet branch pipe 43.

[0051] The first inlet branch pipe 12 and the first outlet branch pipe 42 further serve to fix the additional cooling cavity 3 relative to the main body 2.

[0052] The axial dimension of the additional cooling chamber 3 is 300 mm.

[0053] The inner diameter of the additional cooling chamber 3 is 340 mm.

[0054] The outer diameter of the additional cooling chamber 3 is 395 mm.

[0055] The axial distance between the top of the auxiliary cooling chamber 3 and the bottom of the main body 2 is 1030mm.

[0056] The diameter of the upper opening of the main body 2 is 546mm.

[0057] The bottom inner diameter of body 2 is 340mm.

[0058] The bottom outer diameter of body 2 is 395mm.

[0059] The internal space defined by the inner circumference of the main body 2 is divided into two sections from top to bottom. The upper internal space is a truncated cone shape with the apex pointing downwards, and the lower internal space is a cylinder shape.

[0060] Example 2

[0061] Figure 2 This is a schematic diagram of the structure of the water-cooled screen of the single crystal furnace during material feeding, according to an embodiment of this utility model. Figure 3 This is a schematic diagram of the structure of the water-cooled screen of the single crystal furnace during crystal pulling, according to an embodiment of this utility model.

[0062] refer to Figure 2 , Figure 3 and combined Figure 1 Example 2 provides a single crystal furnace, including the water-cooled screen of Example 1, which can be moved up and down in a controlled manner.

[0063] Specifically, the water-cooled screen can be moved up and down by a motor and transmission mechanism. How to control the up-and-down movement of the water-cooled screen, and how to control the movement height according to different stages of monocrystalline silicon pulling, can be designed based on existing technology; this utility model does not limit this. For example, refer to CN119162645A, CN119162646A, CN216891324U, and CN219385395U.

[0064] The single crystal furnace also includes a crucible 700 disposed below the body 2 of the water-cooled screen and an image sensor 300 disposed above the crucible 700;

[0065] When the water-cooled screen is at any working height, the image sensor 300 can observe the area in the opening of the crucible 700 that is opposite to the bottom opening of the body 2 of the water-cooled screen through the gap between the bottom outer periphery of the additional cooling cavity 3 and the top inner periphery of the body 2.

[0066] The image sensor 300 is specifically a CCD camera.

[0067] The area in the opening of the crucible 700 opposite to the bottom opening of the water-cooled screen body 2 is the area where the crystal rod 200 is located. It should be noted that when the water-cooled screen is at any working height, the image sensor 300 can observe all or part of the area in the opening of the crucible 700 opposite to the bottom opening of the water-cooled screen body 2 through the gap between the bottom outer periphery of the additional cooling cavity 3 and the top inner periphery of the body 2. Under the same conditions, the larger the observable area, the better.

[0068] Figure 2 The image shows the state of the crystal pulling process in its early stages (e.g., the melting stage or the secondary feeding stage). Figure 3 The image sensor 300 captures the crystal pulling process (e.g., the constant diameter growth stage). The image sensor 300 is able to capture the diameter of the crystal rod 200, the liquid outlet distance, and the liquid surface temperature.

[0069] The single crystal furnace also includes components such as the furnace cover 400, the furnace cylinder 600, and the main heater 500.

[0070] Specifically, the image sensor 300 is fixed on the furnace cover 400.

[0071] Specifically, the crucible 700 is used to hold the liquid semiconductor 201.

[0072] The main heater 500 surrounds the upper outer part of the crucible 700 and is used to heat the crucible 700.

[0073] The water-cooled screen is positioned above the crucible 700 and opposite the central region of the crucible 700. The lower opening diameter of the water-cooled screen body 2 is smaller than the upper opening diameter of the water-cooled screen body 2.

[0074] The furnace cylinder 600 surrounds the outside of the main heater 500. The furnace cover 400 covers the upper opening of the furnace cylinder 600.

[0075] The image sensor 300 is located below the top of the furnace cover 400.

[0076] When adding materials a second time, such as Figure 2 As shown, when the water-cooled screen is inside the single-crystal furnace, the liquid semiconductor 201 (specifically, molten silicon) remains within a range of 35mm to 40mm from the bottom of the water-cooled screen, and the image sensor 300 can capture the surface of the molten silicon; when single crystal growth occurs, as... Figure 3As shown, the water-cooled screen descends above the thermal field, and the image sensor 300 can also capture the interface between the single crystal rod 200 and the silicon liquid surface. At the same time, during single crystal growth, the main body 2 of the water-cooled screen and the additional cooling cavity 3 absorb heat simultaneously. The increased heat absorption area allows the water cooling to remove more heat emitted by the silicon crystal per unit time, reducing the temperature of the silicon crystal and increasing the longitudinal temperature gradient at the silicon crystal growth interface. This accelerates the rate at which the silicon molten liquid changes from liquid to solid, correspondingly increasing the pulling speed of the silicon crystal. The maximum pulling speed of the silicon crystal can be increased by 5 mm / h, thereby achieving the purpose of increasing the pulling speed of the silicon crystal. That is, by increasing the heat exchange area of ​​the silicon crystal contact, the longitudinal temperature gradient of the silicon crystal is increased, thereby increasing the pulling speed of the silicon crystal and achieving the purpose of increasing production and efficiency.

[0077] The water-cooled screen structure of this invention has a good cooling effect, which can accelerate the pulling speed of the crystal rod. The water-cooled screen structure does not affect the field of view captured by the image sensor, has a long service life, and has good stability.

[0078] This utility model is not limited to the above-described embodiments. Any modifications, improvements, or substitutions that can be conceived by those skilled in the art without departing from the essential content of this utility model fall within the scope of this utility model.

Claims

1. A water-cooled screen, characterized in that, It includes a cylindrical main body, a cylindrical additional cooling cavity, an inlet water channel, and an outlet water channel; An annular cooling water channel is formed within the main body, and both the inlet water channel and the outlet water channel are connected to the annular cooling water channel of the main body. An annular cooling water channel is formed within the additional cooling cavity, and both the inlet water channel and the outlet water channel are connected to the annular cooling water channel of the additional cooling cavity. The additional cooling cavity extends in the same direction as the main body, the bottom opening of the additional cooling cavity is located above the top opening of the main body, and the outer diameter of the additional cooling cavity is smaller than the inner diameter of the top of the main body.

2. The water screen of claim 1, wherein The inner circumferential surface of the additional cooling cavity defines a cylindrical internal space.

3. The water screen of claim 1, wherein The additional cooling cavity is coaxial with the main body.

4. The water screen of claim 1, wherein The water inlet channel includes a water inlet pipe, a first water inlet branch pipe connected to the end of the water inlet pipe, and a second water inlet branch pipe connected to the end of the water inlet pipe. The end of the first water inlet branch pipe is connected to the lower outer periphery of the additional cooling cavity, and the end of the second water inlet branch pipe is connected to the top of the main body.

5. The water screen of claim 1, wherein The water outlet channel includes a water outlet pipe, a first water outlet branch pipe connected to the beginning of the water outlet pipe, and a second water outlet branch pipe connected to the beginning of the water outlet pipe. The beginning of the first water outlet branch pipe is connected to the lower outer periphery of the additional cooling cavity, and the beginning of the second water outlet branch pipe is connected to the top of the main body.

6. The water screen of claim 1, wherein The axial dimension of the additional cooling chamber is in the range of 270 mm to 330 mm.

7. The water screen of claim 1, wherein The inner diameter of the additional cooling cavity is in the range of 330 mm to 350 mm.

8. The water screen of claim 1, wherein The outer diameter of the additional cooling cavity is in the range of 385 mm to 405 mm.

9. The water screen of claim 1, wherein, The axial distance between the top of the additional cooling chamber and the bottom of the main body is in the range of 900mm to 1100mm.

10. A single crystal furnace characterized by comprising: Includes a water-cooled screen according to any one of claims 1 to 9, wherein the water-cooled screen is capable of controlled vertical movement; It also includes a crucible disposed below the body of the water-cooled screen and an image sensor disposed above the crucible; When the water-cooled screen is at any working height, the image sensor can observe the area in the opening of the crucible that is opposite to the bottom opening of the body of the water-cooled screen through the gap between the bottom outer periphery of the additional cooling cavity and the top inner periphery of the main body.

Images