Boron diffusion device

Abstract

The utility model relates to the technical field of solar cells, in particular to a boron diffusion device, and aims to solve the problem of poor in-sheet square resistance uniformity of a battery sheet after boron diffusion caused by concentrated gas flow direction and poor gas outlet uniformity in the conventional boron diffusion gas inlet mode. In order to achieve the purpose, the boron diffusion device comprises a diffusion furnace body and a first air inlet pipe, and an opening is formed in the first end of the diffusion furnace body; the first gas inlet pipe extends into the second end of the diffusion furnace body from the second end of the diffusion furnace body, and a nozzle is arranged at a gas outlet of the first gas inlet pipe; the gas sprayed by the spray head can be quickly expanded into the radial space of the second end of the whole diffusion furnace body, so that the gas entering the diffusion furnace body through the first gas inlet pipe is relatively uniform instead of centralized gas inlet, the gas from the second end to the first end of the sub-diffusion furnace body can be ensured to be relatively uniform, and the diffusion efficiency is improved. And the in-sheet square resistance uniformity of the battery sheet after boron diffusion is ensured to be relatively good.

Description

Technical Field

[0001] The utility model relates to the technical field of solar cells, and specifically provides a boron diffusion device. Background Art

[0002] Against the backdrop of global climate change, green and low-carbon development has become a global consensus. As a clean, safe, and renewable green energy source, solar energy has the broadest development prospects among new energy sources.

[0003] During solar cell production, boron diffusion plays a crucial role in forming the PN junction. The uniformity of the sheet resistance after boron diffusion also impacts subsequent cell processing, the efficiency of the finished cell, and various electrical parameters. Currently, boron diffusion can be controlled by adjusting the time, temperature, and gas field to achieve the desired sheet resistance and uniformity across the diffusion region of the solar cell. However, gas field stability is not solely dependent on pressure; the gas inlet method also influences this stability and, consequently, the effectiveness of the boron diffusion process.

[0004] The existing boron diffusion air intake method for solar cells is mostly that the gas from the air intake pipe directly enters the furnace body through the air outlet of the air intake pipe. The gas flow is relatively concentrated and the air outlet uniformity is poor, resulting in poor uniformity of the internal square resistance of the cell after boron diffusion.

[0005] Therefore, a boron diffusion device is urgently needed to solve the above technical problems. Utility Model Content

[0006] The utility model aims to solve the above technical problems, namely, to solve the problem that the gas flow direction of the existing boron diffusion air intake method is relatively concentrated and the gas outlet uniformity is poor, which leads to poor uniformity of the internal square resistance of the battery cell after boron diffusion.

[0007] In a first aspect, the present invention provides a boron diffusion device, comprising:

[0008] a diffusion furnace body, wherein a first end of the diffusion furnace body is provided with an opening;

[0009] A first air inlet pipe extends from the second end of the diffusion furnace body into the second end of the diffusion furnace body, and a nozzle is provided at the air outlet of the first air inlet pipe.

[0010] In a specific embodiment of the above-mentioned boron diffusion device, the boron diffusion device also includes a second air inlet pipe, which extends from the second end of the diffusion furnace body into the diffusion furnace body and extends to the middle of the diffusion furnace body. The exhaust port of the second air inlet pipe is located above the diffusion furnace body cavity.

[0011] In a specific embodiment of the above-mentioned boron diffusion device, a nozzle is provided at the air outlet of the second air inlet pipe.

[0012] In a specific embodiment of the above boron diffusion device, the boron diffusion device further includes an exhaust pipe extending from the second end of the diffusion furnace body into the diffusion furnace body, and an exhaust port of the exhaust pipe extends to the opening of the diffusion furnace body.

[0013] In a specific embodiment of the above-mentioned boron diffusion device, the boron diffusion device further includes a first filtering device and an exhaust pump, the exhaust pump is connected to the exhaust pipe, and the exhaust pump is used to extract the gas in the diffusion furnace body to the first filtering device and discharge it.

[0014] In a specific embodiment of the above-mentioned boron diffusion device, a furnace door is provided at the opening of the diffusion furnace body for sealing the opening; and / or

[0015] The material carrying boat is arranged in the diffusion furnace body.

[0016] In a specific embodiment of the above boron diffusion device, the boron diffusion device further includes a furnace door nitrogen pipe, which is connected to the diffusion furnace body and located at the opening of the diffusion furnace body, and is used to fill the diffusion furnace body with nitrogen.

[0017] In a specific embodiment of the above-mentioned boron diffusion device, the boron diffusion device further comprises:

[0018] a large nitrogen pipe connected to the first air inlet pipe and the second air inlet pipe, for delivering nitrogen to the diffusion furnace;

[0019] A small nitrogen pipe is connected to the first air inlet pipe and the second air inlet pipe, and is used to transport nitrogen to the diffusion furnace body.

[0020] In a specific embodiment of the above-mentioned boron diffusion device, the boron diffusion device further comprises:

[0021] a large oxygen pipe connected to the first air inlet pipe and the second air inlet pipe, for supplying oxygen to the diffusion furnace;

[0022] A small oxygen pipe is connected to the first air inlet pipe and the second air inlet pipe, and is used to transport oxygen to the diffusion furnace body.

[0023] In a specific embodiment of the above-mentioned boron diffusion device, the boron diffusion device further comprises:

[0024] The boron trichloride gas pipe is connected to the first gas inlet pipe and the second gas inlet pipe, and is used to transport boron trichloride to the diffusion furnace body.

[0025] When adopting the above-mentioned technical solution, the boron diffusion device of the present invention includes a diffusion furnace body and a first air inlet pipe, and the first end of the diffusion furnace body is provided with an opening; the first air inlet pipe extends from the second end of the diffusion furnace body into the second end of the diffusion furnace body, and the air outlet of the first air inlet pipe is provided with a nozzle; the gas ejected through the nozzle can quickly expand to the radial space of the second end of the entire diffusion furnace body, so that the gas entering the diffusion furnace body through the first air inlet pipe is relatively uniform, rather than centralized air intake, which can ensure that the gas from the second end to the first end of the sub-diffusion furnace body is relatively uniform, thereby ensuring that the intra-chip square resistance uniformity of the battery cell after boron diffusion is better.

[0026] Furthermore, the second air inlet pipe extends into the diffusion furnace body from the second end of the diffusion furnace body and extends to the middle of the diffusion furnace body. The exhaust port of the second air inlet pipe is located above the diffusion furnace body cavity. The air outlet of the second air inlet pipe is provided with a nozzle, and the nozzle is also located above the carrier boat. The gas ejected through the nozzle can quickly expand to the radial space in the middle of the entire diffusion furnace body, so that the gas entering the diffusion furnace body through the second air inlet pipe is relatively uniform, rather than centralized air intake, which can ensure that the gas from the middle section to the first end of the sub-diffusion furnace body is relatively uniform, thereby ensuring that the intra-chip square resistance uniformity of the battery cell after boron diffusion is better.

[0027] In addition, the second air inlet pipe extends from the second end of the diffusion furnace body to the middle part of the diffusion furnace body, avoiding the arrangement of the air inlet pipe on the middle side wall of the diffusion furnace body, avoiding air leakage on the side wall of the diffusion furnace body, ensuring the airtightness of the diffusion furnace body, and further ensuring the uniformity of the square resistance inside the tube of the battery cell after boron diffusion.

[0028] Furthermore, an exhaust pipe extends from the second end of the diffusion furnace body into the diffusion furnace body, and the exhaust port of the exhaust pipe extends to the opening of the diffusion furnace body. This extension of the exhaust pipe from the second end of the diffusion furnace body to the opening of the diffusion furnace body avoids installing the exhaust pipe on the sidewall of the diffusion furnace body, thereby preventing air leakage from the sidewall of the diffusion furnace body, ensuring the airtightness of the diffusion furnace body, and thereby ensuring the uniformity of the internal square resistance of the solar cell after boron diffusion. Furthermore, the exhaust port of the exhaust pipe is located at the first end of the diffusion furnace body, so that gas entering from the first and second air inlet pipes can be extracted by the exhaust pipe only after undergoing boron diffusion. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0030] Figure 1 It is a structural schematic diagram of the boron diffusion device provided by the utility model.

[0031] List of reference numerals:

[0032] 1. Diffusion furnace body; 11. Thermocouple module; 2. First air inlet pipe; 21. Nozzle; 3. Second air inlet pipe; 4. Exhaust pipe; 41. Exhaust pump; 5. Furnace door; 6. Loading boat; 71. Large nitrogen pipe; 72. Small nitrogen pipe; 73. Furnace door nitrogen pipe; 81. Large oxygen pipe; 82. Small oxygen pipe; 91. Boron trichloride pipe. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0034] It should be noted that, in the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0035] Furthermore, it should be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0036] During the production of solar cells, the boron diffusion air intake method is mostly that the gas from the air intake pipe directly enters the furnace body through the air outlet of the air intake pipe. The gas flow is relatively concentrated and the air outlet uniformity is poor, resulting in poor uniformity of the internal square resistance of the cell after boron diffusion.

[0037] In order to solve the above technical problems, Figure 1 As shown, this embodiment discloses a boron diffusion device, which includes a diffusion furnace body 1, a first air inlet pipe 2, a second air inlet pipe 3, an exhaust pipe 4, a loading boat 6, a furnace door 5 and a thermocouple module 11.

[0038] The diffusion furnace body 1 has an opening at its first end, and a furnace door 5 is provided at the opening to seal the opening during boron diffusion. The furnace door 5 is detachably connected to the diffusion furnace body 1 and is opened to allow material to be placed or removed for boron diffusion. When boron diffusion is required, the furnace door 5 is closed to allow gas to enter the diffusion furnace body 1 for boron diffusion.

[0039] The carrier boat 6 is used to place the material to be diffused by boron, wherein the carrier boat 6 is specifically made of carbon material. The length of the carrier boat 6 matches the length of the diffusion furnace body 1. One or more carrier boats 6 are placed side by side in the diffusion furnace body 1.

[0040] Regarding the length of the carrier boat 6, it should be noted that although the length of the carrier boat 6 is matched to the diffusion furnace body 1 in this embodiment, this is not a limitation of the present invention. Without departing from the principles of the present invention, in other embodiments, the length of the carrier boat 6 can be smaller, and multiple carrier boats 6 can be arranged in the longitudinal direction of the diffusion furnace body 1, and multiple carrier boats 6 can also be arranged in the width direction. In other words, the carrier boats 6 can be arranged in a staggered manner or in a series of rows within the diffusion furnace body 1, so that the diffusion furnace body 1 can perform boron diffusion on materials in multiple carrier boats 6 at a time, thereby improving processing efficiency. This does not deviate from the basic principles of the present invention and falls within the scope of protection of the present invention.

[0041] The thermocouple module 11 is disposed within the diffusion furnace body 1, specifically along the length of the diffusion furnace body 1. The thermocouple module 11 is located at the top of the chamber of the diffusion furnace body 1 and is fixed to the top wall of the diffusion furnace body 1. The thermocouple module 11 is used to heat the chamber of the diffusion furnace body 1 to facilitate boron diffusion.

[0042] The first air inlet pipe 2 extends from the second end of the diffusion furnace body 1 into the second end of the diffusion furnace body 1, that is, the air outlet of the first air inlet pipe 2 is located at the second end of the diffusion furnace body 1, and the air outlet of the first air inlet pipe 2 is provided with a nozzle 21; wherein the nozzle 21 is an atomizing nozzle 21, and the gas ejected through the nozzle 21 can quickly expand to the radial space of the second end of the entire diffusion furnace body 1, so that the gas entering the diffusion furnace body 1 through the first air inlet pipe 2 is relatively uniform, rather than centralized air intake, which can ensure that the gas from the second end to the first end of the sub-diffusion furnace body 1 is relatively uniform, thereby ensuring that the intra-chip square resistance uniformity of the battery cell after boron diffusion is better.

[0043] The second air inlet pipe 3 extends from the second end of the diffusion furnace body 1 into the diffusion furnace body 1 and extends to the middle of the diffusion furnace body 1. The exhaust port of the second air inlet pipe 3 is located above the chamber of the diffusion furnace body 1, specifically above the carrier boat 6, and below the thermocouple module 11. The air outlet of the second air inlet pipe 3 is provided with a nozzle 21, which is also located above the carrier boat 6; the nozzle 21 is specifically an atomizing nozzle 21. The gas ejected through the nozzle 21 can quickly expand into the radial space in the middle of the entire diffusion furnace body 1, so that the gas entering the diffusion furnace body 1 through the second air inlet pipe 3 is relatively uniform, rather than centralized, which can ensure that the gas from the middle section to the first end of the sub-diffusion furnace body 1 is relatively uniform, thereby ensuring good uniformity of the intra-chip square resistance of the solar cell after boron diffusion.

[0044] The second air inlet pipe 3 extends from the second end of the diffusion furnace body 1 to the middle part of the diffusion furnace body 1, avoiding the arrangement of the air inlet pipe on the middle side wall of the diffusion furnace body 1, avoiding air leakage from the side wall of the diffusion furnace body 1, ensuring the air tightness of the diffusion furnace body 1, and further ensuring the uniformity of the square resistance inside the tube of the battery cell after boron diffusion.

[0045] The exhaust pipe 4 extends from the second end of the diffusion furnace body 1 into the diffusion furnace body 1, and the exhaust port of the exhaust pipe 4 extends to the opening of the diffusion furnace body 1. This extension of the exhaust pipe 4 from the second end of the diffusion furnace body 1 to the opening of the diffusion furnace body 1 avoids installing the exhaust pipe 4 on the side wall of the diffusion furnace body 1, thereby preventing air leakage from the side wall of the diffusion furnace body 1, ensuring the airtightness of the diffusion furnace body 1, and thereby ensuring the uniformity of the internal square resistance of the solar cell after boron diffusion. In addition, the exhaust port of the exhaust pipe 4 is located at the first end of the diffusion furnace body 1, so that the gas entering from the first and second air inlet pipes 2 and 3 can be extracted by the exhaust pipe 4 only after undergoing boron diffusion.

[0046] The boron diffusion device also includes a first filter device and an air pump 41. The air pump 41 is connected to the air extraction pipe 4. The air pump 41 is used to extract the gas in the diffusion furnace body 1 to the first filter device and discharge it. The gas can be discharged directly, or the gas can be purified and then supplied to the first air inlet pipe 2 and the second air inlet pipe 3 for use. Among them, the air pump 41 is specifically a pneumatic diaphragm pump. The first filter device is specifically a filter water tank, which contains filtered liquid. The exhaust port of the air extraction pipe 4 extends into the filter water tank and is inserted into the filtered liquid. The air pump 41 is connected to the filter water tank through a connecting pipe, and the connecting pipe is connected to the top of the filter water tank. The gas extracted by the air pump 41 is first filtered in the filter water tank and then pumped to other locations.

[0047] Regarding the position of the first filter device, it should be noted that although it is located upstream of the vacuum pump 41 in the present embodiment, this is not a limitation of the present invention. Without departing from the principle of the present invention, in other embodiments, those skilled in the art can set the first filter device downstream of the vacuum pump 41, that is, the vacuum pump 41 draws the gas in the diffusion furnace body 1 to the first filter device for filtration and then discharges it.

[0048] The boron diffusion device also includes a furnace door 5 nitrogen pipe, which is connected to the diffusion furnace body 1 and located at the opening of the diffusion furnace body 1, and is used to fill the diffusion furnace body 1 with nitrogen. Since the furnace door 5 may have airtightness issues, especially after a period of use, there is a high probability that airtightness issues will occur. By supplying nitrogen into the diffusion furnace body 1 through the furnace door 5 nitrogen pipe, other gases in the diffusion furnace body 1 are pushed away, and air that enters the diffusion furnace body 1 through the furnace door 5 can also be isolated outside the furnace door 5, thereby ensuring the airtightness of the diffusion furnace body 1 and the uniformity of the square resistance inside the tube of the battery cell after boron diffusion.

[0049] The boron diffusion device further comprises a large nitrogen pipe 71, a small nitrogen pipe 72, a large oxygen pipe 81, a small oxygen pipe 82 and a boron trichloride pipe 91. The large nitrogen pipe 71 is connected to the first gas inlet pipe 2 and the second gas inlet pipe 3, and is used for delivering nitrogen to the diffusion furnace body 1. The small nitrogen pipe 72 is connected to the first gas inlet pipe 2 and the second gas inlet pipe 3, and is used for delivering nitrogen to the diffusion furnace body 1. The large oxygen pipe 81 is connected to the first gas inlet pipe 2 and the second gas inlet pipe 3, and is used for delivering oxygen to the diffusion furnace body 1. The small oxygen pipe 82 is connected to the first gas inlet pipe 2 and the second gas inlet pipe 3, and is used for delivering oxygen to the diffusion furnace body 1. The boron trichloride pipe 91 is connected to the first gas inlet pipe 2 and the second gas inlet pipe 3, and is used for delivering boron trichloride to the diffusion furnace body 1 for boron diffusion. Valves are arranged on the large nitrogen pipe 71, the small nitrogen pipe 72, the large oxygen pipe 81, the small oxygen pipe 82 and the boron trichloride pipe 91, and are used for controlling whether to supply gas to the diffusion furnace body 1, and are also used for controlling the flow rate of the gas delivered to the diffusion furnace body 1.

[0050] In addition, a second filtering device is arranged on the large nitrogen pipe 71, and is used for filtering the nitrogen delivered to the diffusion furnace body 1, so as to ensure the purity of the nitrogen entering the diffusion furnace body 1. The second filtering device is a common nitrogen filtering device, and the specific structure is not described herein.

[0051] The technical scheme of the present application has been described in combination with the preferred embodiments shown in the drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical schemes after the changes or replacements will all fall within the protection scope of the present application.

Claims

1. A boron diffusion device, characterized in that: It includes: A diffusion furnace body (1), wherein a first end of the diffusion furnace body (1) is provided with an opening; A first air inlet pipe (2) extends from the second end of the diffusion furnace body (1) into the second end of the diffusion furnace body (1), and a nozzle (21) is provided at the air outlet of the first air inlet pipe (2).

2. The boron diffusion device according to claim 1, characterized in that The boron diffusion device further comprises a second air inlet pipe (3), which extends from the second end of the diffusion furnace body (1) into the diffusion furnace body (1) and extends to the middle of the diffusion furnace body (1); the exhaust port of the second air inlet pipe (3) is located above the cavity of the diffusion furnace body (1).

3. The boron diffusion device according to claim 2, characterized in that The air outlet of the second air inlet pipe (3) is provided with a nozzle (21).

4. The boron diffusion device according to claim 1, wherein: The boron diffusion device further comprises an exhaust pipe (4), which extends from the second end of the diffusion furnace body (1) into the diffusion furnace body (1), and the exhaust port of the exhaust pipe (4) extends to the opening of the diffusion furnace body (1).

5. The boron diffusion device according to claim 4, characterized in that The boron diffusion device further comprises a first filtering device and an air pump (41), wherein the air pump (41) is connected to the air extraction pipe (4), and the air pump (41) is used to extract the gas in the diffusion furnace body (1) to the first filtering device and discharge it.

6. The boron diffusion device according to claim 1, wherein: A furnace door (5) is provided at the opening of the diffusion furnace body (1) for sealing the opening; and / or A material carrying boat (6) is arranged in the diffusion furnace body (1).

7. The boron diffusion device according to claim 1, wherein: The boron diffusion device further comprises a furnace door (5) nitrogen pipe, which is connected to the diffusion furnace body (1) and is located at the opening of the diffusion furnace body (1) and is used for filling nitrogen into the diffusion furnace body (1).

8. The boron diffusion device according to claim 2, wherein: The boron diffusion device further comprises: a large nitrogen pipe (71), connected to the first air inlet pipe (2) and the second air inlet pipe (3), and used for conveying nitrogen to the diffusion furnace body (1); A small nitrogen pipe (72) is connected to the first air inlet pipe (2) and the second air inlet pipe (3) and is used to transport nitrogen to the diffusion furnace body (1).

9. The boron diffusion device according to claim 2, characterized in that The boron diffusion device further comprises: a large oxygen pipe (81), connected to the first air inlet pipe (2) and the second air inlet pipe (3), for supplying oxygen to the diffusion furnace body (1); A small oxygen pipe (82) is connected to the first air inlet pipe (2) and the second air inlet pipe (3) and is used to transport oxygen to the diffusion furnace body (1).

10. The boron diffusion device according to claim 2, characterized in that The boron diffusion device further comprises: A boron trichloride gas pipe (91) is connected to the first gas inlet pipe (2) and the second gas inlet pipe (3) and is used to transport boron trichloride to the diffusion furnace body (1).

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