A current equalization plate structure and a BC battery silicon wafer diffusion device comprising the same

Abstract

The utility model provides a kind of current sharing plate structure and the BC battery silicon wafer diffusion device including it, the current sharing plate structure includes current sharing plate body, the side surface of current sharing plate body is divided into center area, and the edge area of the center area circumferentially;The edge area is uniformly distributed with horn-shaped air hole, the diameter of the horn-shaped air hole gradually increases along air inlet direction;The center area is uniformly distributed with straight cylinder air hole.The utility model is specifically designed to the structure of current sharing plate, divides edge area and center area on current sharing plate body, and distinguishes and sets air hole, improves the uniformity of furnace mouth area phosphorus source distribution, promotes the consistency of silicon wafer square resistance, can be according to the distribution adjustment of air hole of furnace body size, strong adaptability, simple structure, suitable for industrialization popularization and application.

Description

Technical Field

[0001] This utility model belongs to the field of battery phosphorus diffusion technology, and relates to a current equalization plate structure and a BC battery silicon wafer diffusion device including the same. Background Technology

[0002] Due to the full-contact design of the back electrode in BC batteries, the uniformity of the phosphorus diffusion process is extremely important. In traditional diffusion furnaces, turbulent airflow and uneven distribution of dopant sources at the furnace opening can easily lead to significant differences in sheet resistance between the edge and center regions of the silicon wafer, affecting the electrical performance of the battery.

[0003] In existing technologies, current equalization plates mostly adopt a uniformly distributed fixed aperture structure, but they are not optimized for the size of BC cell silicon wafers (such as large sizes of 210mm) and furnace airflow characteristics, resulting in prominent problems of insufficient diffusion at the edge or excessive diffusion at the center of large-size silicon wafers.

[0004] Therefore, there is an urgent need to design a flow equalization plate structure to overcome the shortcomings of existing technologies and meet the needs of practical applications. Utility Model Content

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a flow equalization plate structure and a BC battery silicon wafer diffusion device including the same, particularly a furnace mouth flow equalization plate structure and diffusion device adapted to the phosphorus diffusion process of BC batteries. In this invention, through specific design of the flow equalization plate structure, an edge area and a central area are divided on the plate body, and pores are set separately, improving the uniformity of phosphorus source distribution in the furnace mouth area and enhancing the consistency of silicon wafer sheet resistance. The distribution of pores can be adjusted according to the furnace size, exhibiting strong adaptability, simple structure, and suitability for industrial application.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a flow equalization plate structure, the flow equalization plate structure including a flow equalization plate body, one side surface of the flow equalization plate body being divided into a central area and a peripheral edge area of ​​the central area; the edge area is evenly distributed with trumpet-shaped air holes, the diameter of the trumpet-shaped air holes gradually increasing along the air intake direction; the central area is evenly distributed with cylindrical air holes.

[0008] Preferably, a baffle is provided at the junction of the central area and the edge area.

[0009] Preferably, the baffle includes at least one first baffle and at least one second baffle, wherein the second baffle is slidably fitted inside the first baffle.

[0010] Preferably, the baffle is electrically connected to a motor, which is used to control the extension and retraction length and opening and closing angle of the baffle.

[0011] Preferably, the baffle is a silicon nitride ceramic baffle or a glass baffle.

[0012] Preferably, the thickness of the baffle is 40μm to 60μm, such as 40μm, 45μm, 50μm, 55μm, 60μm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0013] Preferably, the ratio of the width of the edge region to the width of the flow equalization plate body is 1:(5~6), such as 1:5, 1:52, 1:54, 1:56, 1:58, 1:6, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0014] Preferably, the horn-shaped air hole includes a small-diameter end and a large-diameter end, with the small-diameter end facing the air intake direction.

[0015] Preferably, the diameter of the smaller diameter end is 4mm to 6mm, such as 4mm, 4.5mm, 5mm, 5.5mm, 6mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0016] Preferably, the diameter of the large-diameter end is 8mm to 12mm, such as 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0017] Preferably, the distance between the centers of adjacent horn-shaped air holes is 1mm to 3mm, such as 1mm, 1.5mm, 2mm, 2.5mm, 3mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0018] Preferably, the distribution density of the funnel-shaped vents in the edge area is 200 vents / m² to 250 vents / m².

[0019] Preferably, the diameter of the cylindrical air hole is 4mm to 6mm, such as 4mm, 4.5mm, 5mm, 5.5mm, 6mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0020] Preferably, the distance between the centers of adjacent cylindrical air holes is 0.5mm to 2mm, such as 0.5mm, 1mm, 1.5mm, 2mm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0021] Preferably, the distribution density of the cylindrical pores in the central area is 300 pores / m² to 350 pores / m².

[0022] Preferably, the surface of the flow equalization plate body facing away from the air intake direction is evenly distributed with a plurality of flow guide grooves, and the plurality of flow guide grooves are arranged in parallel.

[0023] Preferably, the distance between adjacent guide grooves is 8mm to 12mm, such as 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0024] Preferably, the width of the guide groove is 0.4mm to 0.6mm, such as 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0025] Preferably, the depth of the guide groove is 0.15mm to 0.25mm, such as 0.15mm, 0.2mm, 0.25mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0026] Preferably, the flow equalization plate body is a quartz plate.

[0027] Preferably, the thickness of the flow equalization plate body is greater than or equal to 400μm, such as 400μm, 450μm, 500μm, 550μm, 600μm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0028] Preferably, the length of the flow equalization plate body is 300mm~600mm, such as 300mm, 350mm, 400mm, 450mm, 500mm, 550mm, 600mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0029] Preferably, the width of the flow equalization plate body is 300mm~600mm, such as 300mm, 350mm, 400mm, 450mm, 500mm, 550mm, 600mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0030] Preferably, the light transmittance of the flow equalization plate body is greater than or equal to 95%, such as 95%, 95.5%, 96%, 97%, 98%, 98.5%, 99%, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0031] Secondly, this utility model provides a BC battery silicon wafer diffusion device, the BC battery silicon wafer diffusion device including a furnace body and at least one flow equalization plate structure disposed inside the furnace body; the flow equalization plate structure adopts the flow equalization plate structure described in the first aspect.

[0032] Preferably, the flow equalization plate structure is disposed near the inner wall of the furnace opening of the furnace body, and the small diameter end of the trumpet-shaped air hole is disposed facing the furnace opening.

[0033] Preferably, a positioning boss is provided on one side edge of the flow equalization plate body, and the positioning boss is used to engage with the slot inside the furnace opening.

[0034] Preferably, the maximum linear distance between the flow equalization plate body and the furnace opening is 15mm~20mm, such as 15mm, 156mm, 17mm, 18mm, 19mm, 20mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0035] Preferably, a thermocouple and a differential pressure sensor are provided at the furnace opening.

[0036] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description.

[0037] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0038] In this utility model, by specifically designing the structure of the flow equalization plate, an edge area and a central area are divided on the body of the flow equalization plate, and air holes are set separately, which improves the uniformity of phosphorus source distribution in the furnace mouth area and enhances the consistency of silicon wafer sheet resistance. The distribution of air holes can be adjusted according to the size of the furnace body, which is highly adaptable, simple in structure, and suitable for industrial promotion and application. Attached Figure Description

[0039] 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.

[0040] Figure 1 A schematic diagram showing the flow equalization plate structure provided by this utility model facing the air intake direction;

[0041] Figure 2 A schematic diagram of the flow equalization plate structure provided by this utility model facing away from the air intake direction;

[0042] Figure 3 A schematic diagram showing the flow equalization plate structure provided by this utility model with a baffle.

[0043] Figure 4 A schematic diagram of a current equalization plate structure installed in the BC battery silicon wafer diffusion device provided by this utility model.

[0044] Among them, 1-flow equalization plate body; 2-central area; 3-edge area; 4-flare-shaped air hole; 5-baffle; 6-flow guide groove; 7-positioning boss. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0046] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0047] It should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0048] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0049] In one specific embodiment, the present invention provides a flow equalization plate structure, such as... Figure 1 , Figure 2 and Figure 3 As shown, the flow equalization plate structure includes a flow equalization plate body 1. One side surface of the flow equalization plate body 1 is divided into a central area 2 and an edge area 3 around the central area 2. Horn-shaped air holes 4 are evenly distributed on the edge area 3, and the diameter of the horn-shaped air holes 4 gradually increases along the air intake direction. Straight cylindrical air holes are evenly distributed on the central area 2.

[0050] It should be noted that existing flow equalization plates mostly adopt a uniformly distributed fixed aperture structure, which cannot better homogenize the airflow at the furnace opening, resulting in insufficient diffusion at the edges or excessive diffusion at the center of large-size silicon wafers. This utility model solves the problem of uneven diffusion caused by turbulent airflow at the furnace opening through the design of zoned flow guidance and dynamic air hole adjustment, thereby improving the overall sheet resistance uniformity of silicon wafers.

[0051] It should be noted that the trumpet-shaped vent 4 in this utility model reduces airflow resistance through a tapered flaring design, thereby increasing the phosphorus source concentration in the edge region 3 by 30% to 40%, effectively alleviating the problem of insufficient diffusion at the edge of large-size silicon wafers; the central region 2 suppresses over-diffusion, and the cylindrical vent, combined with a low-density distribution, reduces phosphorus source accumulation in the central region 2, reducing the sheet resistance uniformity from 8.6% to 2.3%, meeting the high-precision doping requirements of BC cells for the grid line region.

[0052] Furthermore, a baffle 5 is provided at the junction of the central area 2 and the edge area 3.

[0053] Furthermore, the baffle 5 includes at least one first baffle and at least one second baffle, the second baffle being slidably fitted inside the first baffle.

[0054] Furthermore, the baffle 5 is electrically connected to a motor, which is used to control the extension and retraction length and opening and closing angle of the baffle 5.

[0055] It should be noted that in this invention, the airflow can be adjusted in real time by controlling the opening and closing degree of the baffle 5. The opening and closing degree can be adjusted from 0 to 30°, which can reduce the problem of poor uniformity of silicon wafer diffusion caused by airflow turbulence.

[0056] Furthermore, the baffle 5 is a silicon nitride ceramic baffle or a glass baffle.

[0057] It should be noted that the baffle 5 in this utility model is preferably made of silicon nitride ceramic baffle or glass baffle because it can be used for a long time at high temperature. Metal materials cannot be selected, as they are prone to generating metal complex centers during phosphorus diffusion doping.

[0058] Furthermore, the thickness of the baffle 5 is 40μm~60μm, such as 40μm, 45μm, 50μm, 55μm, 60μm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0059] Furthermore, the ratio of the width of the edge region 3 to the width of the flow equalization plate body 1 is 1:(5~6), such as 1:5, 1:52, 1:54, 1:56, 1:58, 1:6, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0060] The width of the edge region 3 in this invention can be expanded or reduced accordingly with the size of the flow equalization plate body 1. The ratio of the width of the edge region 3 to the width of the flow equalization plate body 1 is limited to 1:(5~6) because within this range, the airflow diffusion intensity of the edge region 3 can be enhanced while the doping amount can be balanced. If it is not within this range, it may lead to poor phosphorus diffusion uniformity.

[0061] Furthermore, the horn-shaped air hole 4 includes a small diameter end and a large diameter end, with the small diameter end facing the air intake direction.

[0062] Furthermore, the diameter of the smaller diameter end is 4mm to 6mm, such as 4mm, 4.5mm, 5mm, 5.5mm, 6mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range also apply.

[0063] Furthermore, the diameter of the large-diameter end is 8mm to 12mm, such as 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range also apply.

[0064] The diameter of the small diameter end in this invention is 4mm~6mm and the diameter of the large diameter end is 8mm~12mm. This is because the gas diffusion intensity is improved within this range. If it is not within this range, the large diameter will lose the effect of the flow equalization plate in dispersing the airflow, and the small diameter will cause the apertures on the flow equalization plate to become blocked.

[0065] Furthermore, the distance between the centers of adjacent funnel-shaped vents 4 is 1mm to 3mm, such as 1mm, 1.5mm, 2mm, 2.5mm, 3mm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0066] Furthermore, the distribution density of the trumpet-shaped pores 4 in the edge region 3 is 200 pores / m² to 250 pores / m².

[0067] In this invention, the distance between the centers of adjacent trumpet-shaped pores 4 is 1mm to 3mm and the distribution density is 200 pores / m² to 250 pores / m². This is because the gas diffusion intensity is improved within this range. If it is not within this range, the doping uniformity may deteriorate.

[0068] Furthermore, the diameter of the straight cylindrical vent is 4mm to 6mm, such as 4mm, 4.5mm, 5mm, 5.5mm, 6mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0069] Furthermore, the distance between the centers of adjacent cylindrical vents is 0.5mm to 2mm, such as 0.5mm, 1mm, 1.5mm, 2mm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0070] Furthermore, the distribution density of the straight cylindrical pores in the central region 2 is 300 pores / m² to 350 pores / m².

[0071] In this invention, the distribution density of the straight cylindrical pores in the central region 2 is 300 pores / m² to 350 pores / m². This is because the gas diffusion intensity can be improved within this range. If it is not within this range, the doping uniformity may be deteriorated.

[0072] Furthermore, a number of guide grooves 6 are evenly distributed on the side surface of the flow equalization plate body 1 facing away from the air intake direction, and the number of guide grooves 6 are arranged in parallel.

[0073] It should be noted that the number of elements in this utility model can be 1, 2, 3, 4, 5, 6, etc., and will not be exhaustively listed here. Those skilled in the art can make adaptive adjustments according to the actual situation. The design of the flow guide groove 6 can guide the horizontal airflow to be evenly distributed, improve the phosphorus source utilization rate by 15%, and reduce the phosphorus source consumption per diffusion by 10%. The flow guide groove 6 can be etched along the silicon wafer arrangement direction in the direction opposite to the air intake direction of the flow equalization plate body 1.

[0074] Furthermore, the distance between adjacent guide grooves 6 is 8mm to 12mm, such as 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0075] Furthermore, the width of the guide groove 6 is 0.4mm to 0.6mm, such as 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0076] Furthermore, the depth of the guide groove 6 is 0.15mm to 0.25mm, such as 0.15mm, 0.2mm, 0.25mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0077] The width of the guide groove 6 in this invention is 0.4mm~0.6mm and 0.4mm~0.6mm because the gas diffusion intensity can be improved within this range. If it is not within this range, the doping uniformity may be deteriorated.

[0078] Furthermore, the flow equalization plate body 1 is a quartz plate.

[0079] It should be noted that the flow equalization plate body 1 in this utility model is made of quartz plate, which is resistant to high temperature and has high light transmittance, thus avoiding thermal stress deformation.

[0080] Furthermore, the thickness of the flow equalization plate body 1 is greater than or equal to 400μm, such as 400μm, 450μm, 500μm, 550μm, 600μm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0081] In this invention, the thickness of the flow equalization plate body 1 is greater than or equal to 400μm because the flow equalization plate can be used for a long time within this range, resulting in a high utilization rate. If it is outside this range, the thickness of the flow equalization plate body 1 will be too thin, and the service life will be reduced.

[0082] Furthermore, the length of the flow equalization plate body 1 is 300mm~600mm, such as 300mm, 350mm, 400mm, 450mm, 500mm, 550mm, 600mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0083] Furthermore, the width of the flow equalization plate body 1 is 300mm~600mm, such as 300mm, 350mm, 400mm, 450mm, 500mm, 550mm, 600mm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0084] Furthermore, the light transmittance of the flow equalization plate body 1 is greater than or equal to 95%, such as 95%, 95.5%, 96%, 97%, 98%, 98.5%, 99%, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0085] In another specific embodiment, the present invention provides a BC battery silicon wafer diffusion device, such as... Figure 4 As shown, the BC cell silicon wafer diffusion device includes a furnace body and at least one flow equalization plate structure disposed inside the furnace body; the flow equalization plate structure adopts the above-mentioned flow equalization plate structure.

[0086] Furthermore, the flow equalization plate structure is set near the inner wall of the furnace opening of the furnace body, and the small diameter end of the trumpet-shaped air hole 4 is set towards the furnace opening.

[0087] Furthermore, a positioning boss 7 is provided on one side edge of the flow equalization plate body 1, which is used to engage with the slot inside the furnace opening.

[0088] It should be noted that the positioning boss 7 in this utility model is mainly used to engage with the slot on the inner wall of the furnace opening, thereby ensuring that the gap between the flow equalization plate body 1 and the furnace body is 15~20mm.

[0089] Furthermore, the maximum linear distance between the flow equalization plate body 1 and the furnace opening is 15mm~20mm, such as 15mm, 156mm, 17mm, 18mm, 19mm, 20mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0090] In this invention, the maximum linear distance between the flow equalization plate body 1 and the furnace opening is 15mm~20mm, because within this range it is beneficial to timely divert the clustered airflow at the furnace opening.

[0091] Furthermore, a thermocouple and a differential pressure sensor are installed at the furnace opening.

[0092] It should be noted that a thermocouple and a differential pressure sensor are installed at the furnace opening in this utility model, which can monitor the airflow speed and temperature gradient in real time, and link the opening degree of the baffle 5 and the air intake valve flow through a PID algorithm; the specific installation position, model and quantity of the thermocouple and differential pressure sensor are not limited, and those skilled in the art can make adaptive adjustments according to the actual situation.

[0093] Example 1

[0094] This embodiment provides a flow equalization plate structure, wherein:

[0095] The flow equalization plate structure includes a flow equalization plate body 1. One side surface of the flow equalization plate body 1 is divided into a central area 2 and an edge area 3 around the central area 2. Funnel-shaped air holes 4 are evenly distributed on the edge area 3, and the diameter of the funnel-shaped air holes 4 gradually increases along the air intake direction. Straight cylindrical air holes are evenly distributed on the central area 2.

[0096] A baffle 5 is provided at the junction of the central area 2 and the edge area 3. The baffle 5 includes a first baffle and a second baffle. The second baffle is slidably fitted inside the first baffle. The baffle 5 is electrically connected to a motor. The motor is used to control the extension and retraction length and opening and closing angle of the baffle 5. The baffle 5 is a silicon nitride ceramic baffle and the thickness of the baffle 5 is 50μm.

[0097] The horn-shaped air hole 4 includes a small diameter end and a large diameter end. The small diameter end is set towards the air intake direction. The diameter of the small diameter end is 5mm, and the diameter of the large diameter end is 10mm. The distance between the centers of adjacent horn-shaped air holes 4 is 2mm. The distribution density of the horn-shaped air holes 4 in the edge area 3 is 230 holes / square meter.

[0098] The diameter of the cylindrical pores is 5 mm, the distance between the centers of adjacent cylindrical pores is 1.5 mm, and the distribution density of the cylindrical pores in the central area 2 is 300 pores / square meter.

[0099] Two guide grooves 6 are evenly distributed on the side surface of the flow equalizer body 1 facing away from the air intake direction. The two guide grooves 6 are arranged in parallel, the distance between adjacent guide grooves 6 is 10mm, the width of the guide groove 6 is 0.5mm, and the depth of the guide groove 6 is 0.2mm.

[0100] The flow equalization plate body 1 is a quartz plate with a thickness of 400μm, a length of 300mm, a width of 300mm, and a light transmittance of ≥95%.

[0101] In this embodiment, the installation of the flow equalization plate structure in the furnace body includes: horizontally fixing the flow equalization plate body 1 to the inner wall of the quartz furnace opening of the diffusion furnace, with a distance of 15~20mm between it and the silicon wafer carrier boat.

[0102] The furnace temperature is 850℃±1℃ (pre-deposition stage) and 900℃±2℃ (propulsion stage). The furnace uses a PH3 / N2 mixed gas (concentration 8%), with a main inlet flow rate of 20L / min and auxiliary inlet flow dynamically adjusted via baffle 5.

[0103] When the temperature detection value of the edge zone 3 is higher than that of the center zone 22°, the opening degree of the baffle 5 is adjusted to 20°, and the air intake ratio of the edge zone 3 is increased to 30%.

[0104] Comparative Example 1

[0105] This comparative example provides a flow equalization plate structure, which differs from Example 1 in that the flow equalization plate body 1 does not have the division of edge region 3 and center region 2, and the same straight cylindrical air holes are directly distributed on the flow equalization plate body 1. All other conditions are the same as in Example 1.

[0106] The sheet resistance and uniformity of the flow equalization plate structures in the above embodiments and comparative examples after the phosphorus diffusion process were tested, and the results are shown in Table 1 below.

[0107]

[0108] The center position in Table 1 can be found at point 2 in the center area. The positions of edge corner 1, edge corner 2, edge corner 3, and edge corner 4 can be selected sequentially at the four corners of the center area 2. The unit of sheet resistance is Ω ohms. The test method is a four-probe sheet resistance test. The uniformity test method is also a four-probe sheet resistance test.

[0109] As shown in Table 1, the uniformity of phosphorus diffusion resistance is significantly improved after the flow equalization plate structure of this utility model is applied to the furnace body. The uniformity within a single plate is optimized from 8% to less than 3%, showing a significant improvement effect.

[0110] In summary, this utility model, through the specific design of the flow equalization plate structure, divides the flow equalization plate body 1 into an edge area 3 and a central area 2, and sets air holes separately, which improves the uniformity of phosphorus source distribution in the furnace mouth area, enhances the consistency of silicon wafer sheet resistance, and allows for adjustment of air hole distribution according to furnace size. It is highly adaptable, has a simple structure, and is suitable for industrial promotion and application.

[0111] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A flow equalization plate structure, characterized in that, The flow equalization plate structure includes a flow equalization plate body, one side surface of which is divided into a central area and a circumferential edge area of ​​the central area; The edge area is evenly distributed with trumpet-shaped air holes, and the diameter of the trumpet-shaped air holes gradually increases along the air intake direction; The central area is evenly distributed with cylindrical air holes.

2. The flow equalization plate structure according to claim 1, characterized in that, A baffle is provided at the boundary between the central area and the edge area; The baffle includes at least one first baffle and at least one second baffle, wherein the second baffle is slidably fitted inside the first baffle; The baffle is electrically connected to a motor, which is used to control the extension and retraction length and opening and closing angle of the baffle.

3. The flow equalization plate structure according to claim 2, characterized in that, The baffle is a silicon nitride ceramic baffle or a glass baffle; The thickness of the baffle is 40μm~60μm.

4. The flow equalization plate structure according to claim 1, characterized in that, The ratio of the width of the edge region to the width of the flow equalization plate body is 1:(5~6).

5. The flow equalization plate structure according to claim 1, characterized in that, The horn-shaped air hole includes a small-diameter end and a large-diameter end, with the small-diameter end facing the air intake direction; The diameter of the smaller diameter end is 4mm~6mm; The diameter of the large-diameter end is 8mm~12mm; The distance between the centers of adjacent funnel-shaped air holes is 1mm to 3mm; The distribution density of the trumpet-shaped pores in the edge area is 200 pores / m² to 250 pores / m².

6. The flow equalization plate structure according to claim 1, characterized in that, The diameter of the straight cylindrical air hole is 4mm~6mm; The distance between the centers of adjacent cylindrical air holes is 0.5mm to 2mm; The distribution density of the cylindrical pores in the central area is 300 pores / m² to 350 pores / m².

7. The flow equalization plate structure according to claim 1, characterized in that, The surface of the flow equalization plate body facing away from the air intake direction is evenly distributed with a number of flow guide grooves, and the number of flow guide grooves are arranged in parallel. The distance between adjacent guide channels is 8mm~12mm; The width of the guide groove is 0.4mm~0.6mm; The depth of the guide groove is 0.15mm~0.25mm.

8. The flow equalization plate structure according to claim 1, characterized in that, The flow equalization plate body is a quartz plate; The thickness of the flow equalization plate body is greater than or equal to 400 μm; The length of the flow equalization plate body is 300mm~600mm; The width of the flow equalization plate body is 300mm~600mm; The light transmittance of the flow equalization plate body is greater than or equal to 95%.

9. A silicon wafer diffusion device for BC batteries, characterized in that, The BC cell silicon wafer diffusion device includes a furnace body and at least one flow equalization plate structure disposed inside the furnace body; The flow equalization plate structure adopts the flow equalization plate structure according to any one of claims 1-8.

10. The BC battery silicon wafer diffusion apparatus according to claim 9, characterized in that, The flow equalization plate structure is located near the inner wall of the furnace opening of the furnace body, and the small diameter end of the trumpet-shaped air hole is oriented towards the furnace opening; The flow equalization plate body has a positioning boss on one side edge, which is used to engage with the groove on the inner wall of the furnace opening. The maximum linear distance between the flow equalization plate body and the furnace opening is 15mm~20mm; Thermocouples and differential pressure sensors are installed at the furnace opening.

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