A polycrystalline bifacial cell passivation furnace

Abstract

The present invention discloses a passivation furnace for polycrystalline double-sided batteries, which relates to the technical field of battery passivation equipment. The passivation furnace includes a furnace body, a feed inlet opened at one end of the furnace body, and a furnace cover covering the feed inlet. A passivation rack, a connecting member, a driving member, and an air inlet assembly are provided inside the furnace body. The wafers are connected to the passivation rack around the central axis of the passivation rack. Several linearly arranged air outlet openings are formed in the air inlet assembly. An air inlet communicating with the cavity is opened at the bottom of the furnace body. A heating wire coiled in the cavity is further provided in the cavity of the air inlet assembly. The passivation furnace can repeatedly heat the blown passivation gas to ensure that the temperatures of all parts inside the passivation furnace are the same. Therefore, the heating and passivation effects of the gas on all parts of the wafers are the same, avoiding uneven passivation degrees caused by uneven gas temperature. In addition, the two sides of the wafers can be heated and passivated simultaneously, ensuring that the passivation quality of all parts of the wafers is the same.

Description

Technical Field

[0001] The present invention relates to the technical field of battery passivation equipment, and particularly to a polycrystalline double-sided battery passivation furnace. Background Art

[0002] Photovoltaic cells (referred to as PV cells for short) are used to directly convert solar light energy into electrical energy. Silicon-based silicon solar cells widely used in ground PV systems can be divided into monocrystalline silicon, polycrystalline silicon, and amorphous silicon solar cells. In terms of comprehensive performance such as energy conversion efficiency and service life, monocrystalline silicon and polycrystalline silicon cells are superior to amorphous silicon cells.

[0003] Surface passivation of crystalline silicon solar cells has always been a top priority in design and optimization. From the early stage with only back electric field passivation, to front surface silicon nitride passivation, and then to the PERC / PERL design with local opening contacts of passivation by introducing dielectric layers such as silicon oxide, aluminum oxide, and silicon nitride on the back. Although this structure temporarily alleviates the problem of back passivation, it does not eradicate it. The high recombination rate at the openings still exists, and it further complicates the process.

[0004] The passivation process is to place the solar cell in a hydrogen plasma and apply a negative bias pulse with a predetermined voltage, a predetermined frequency, and a predetermined time width to the solar cell. In this way, hydrogen ions in the plasma will be attracted and quickly injected into the interior of the solar cell, so that silicon crystal defects in the passivated solar cell can be achieved in a short time.

[0005] Meanwhile, under appropriate operating parameters, the anti-reflection layer characteristics of the solar cell will not be damaged. Passivation can increase the short-circuit current and open-circuit voltage and significantly reduce the series resistance of the solar cell to increase the fill factor, thereby improving the overall efficiency.

[0006] Currently, a Chinese patent with the publication number CN210956714U discloses a passivation furnace for silicon oxynitride PERC back passivation, which performs passivation through stepped temperature settings and adds N2O to improve the back passivation effect; in addition, a heat exchange mechanism is added to transfer the end gas to the tail end of the furnace tube when the furnace door is opened, minimizing heat loss as much as possible, thereby saving energy.

[0007] This kind of passivation furnace can achieve zoned control of the temperature inside the furnace, making the temperature control more precise. However, due to the uneven gas temperature in each part of the passivation furnace, the passivation degree of each part of the wafer is different, so it is easy to cause uneven quality of each part of the wafer. Summary of the Invention

[0008] In view of the above technical problems, the present invention overcomes the shortcomings of the prior art and provides a polycrystalline double-sided battery passivation furnace.

[0009] To solve the above technical problems, the present invention provides a passivation furnace for polycrystalline double-sided batteries.

[0010] Technical effect: It can repeatedly heat the blown passivation gas to ensure that the temperatures of all parts in the passivation furnace are the same. Therefore, the heating and passivation effects of the gas on each part of the wafer are the same, avoiding uneven passivation due to uneven gas temperature. In addition, it can heat and passivate both sides of the wafer simultaneously, ensuring the same passivation quality for all parts of the wafer.

[0011] The further limited technical solution of the present invention is:

[0012] A passivation furnace for polycrystalline double-sided batteries includes a furnace body, a feed inlet opened at one end of the furnace body, and a furnace cover covering the feed inlet. Inside the furnace body, there is

[0013] a passivation rack, which includes several fixing parts for connecting wafers. The wafers are connected to the passivation rack around the central axis of the passivation rack. The passivation rack includes an intermediate rod. The center position at the bottom of the furnace body is matched with the intermediate rod. When the passivation rack is connected inside the furnace body, the intermediate rod is rotatably connected to the bottom end of the furnace body;

[0014] a connecting part, which is arranged at the center position of the bottom of the furnace body and is used to sleeved the intermediate rod and connect the end of the intermediate rod;

[0015] a driving part, which is arranged on the furnace cover corresponding to the end of the intermediate rod. The intermediate rod is sleeved and connected inside the driving part to drive the intermediate rod to rotate;

[0016] an air inlet assembly, which includes an air wall connected to the inner wall of the furnace body. A cavity for accommodating gas is formed between the air wall and the inner wall of the furnace body. One side of the air wall is connected to the bottom of the furnace body. Several linearly arranged air outlet holes are opened on the air wall. An air inlet communicating with the cavity is opened at the bottom of the furnace body;

[0017] A heating wire coiled in the cavity is also arranged in the cavity.

[0018] Furthermore, several linearly arranged connecting rods are arranged on the intermediate rod. The end of the connecting rod is rotatably connected with a fixing frame. Several suction cups arranged around the center line are arranged on the inner side surface of the fixing frame. The suction cups are correspondingly arranged on the side surface of the wafer. The two sides of the fixing frame are eccentrically rotatably connected to the two side connecting rods.

[0019] For the above-mentioned passivation furnace for polycrystalline double-sided batteries, the connecting part includes a connecting collar formed at the center position of the inner bottom surface of the furnace body. When the passivation rack is connected, the intermediate rod is sleeved and rotatably connected inside the connecting collar. Several support rods perpendicular to the inner side wall of the furnace body are arranged inside the furnace body. A semi-circular support is fixed at the end of the support rod for supporting the intermediate rod. The support rods are located at the interval positions of the fixing parts.

[0020] The above-mentioned passivation furnace for polycrystalline double-sided batteries, the driving member includes a rotating shaft rotatably connected to the furnace cover and penetrating the furnace cover, a driving motor is fixed on the top of the furnace cover, a driving worm gear is coaxially fixed on the rotating shaft, and a driving worm is formed on the output shaft of the driving motor, and the driving worm meshes with the driving worm gear.

[0021] The above-mentioned passivation furnace for polycrystalline double-sided batteries, a driving sleeve is fixed on a section of the rotating shaft located inside the furnace body, and a plurality of driving grooves are formed on the inner side wall of the driving sleeve and arranged around the center line of the driving sleeve. A plurality of driving blocks corresponding to the driving grooves are formed at the end of the middle rod, and the driving blocks are embedded in the driving grooves during connection.

[0022] The above-mentioned passivation furnace for polycrystalline double-sided batteries, the air outlets are distributed in two rows on the air wall, and the two rows of air outlets are arranged opposite to each other for blowing gas to the wafers. One side of the air wall connecting the bottom surface of the furnace body forms an annular wall, the air inlet is communicated with the annular wall area, and an exhaust port is also provided on the bottom surface of the furnace body for discharging the gas in the furnace body.

[0023] The above-mentioned passivation furnace for polycrystalline double-sided batteries, the heating wire is connected in the cavity in a cylindrical spiral shape, and the furnace cover and the furnace body are connected and sealed by a flange.

[0024] The beneficial effects of the present invention are:

[0025] (1) In the present invention, an operator connects several wafers to the passivation rack, sends the passivation rack into the passivation furnace from the feed port of the furnace body, the middle rod of the passivation rack cooperates with the connecting member, and then closes the furnace cover on the feed port, so that the whole passivation rack can be connected in the passivation furnace to complete the passivation process of the wafers; during the passivation process, the air inlet of the air inlet assembly continuously blows the passivation gas into the cavity inside the air wall, and at the same time, the heating wire in the cavity continuously heats the passivation gas to the preset temperature, and then blows the passivation gas to the wafers from the air inlet. At this time, the driving member drives the middle rod to rotate, and several wafers on the passivation rack can receive the blowing of the passivation gas in different directions through rotation, so as to ensure that the passivation effects of all parts of the wafers are the same and improve the uniformity of wafer passivation;

[0026] (2) In the present invention, a suction cup is arranged on the fixing frame, and the wafer can be connected to the fixing frame through the suction cup, and the whole fixing frame is eccentrically rotatably connected to the connecting rods on both sides. Therefore, when the middle rod rotates, due to the action of gravity, the wafer and the fixing frame are always perpendicular to the horizontal plane. When the middle rod rotates in the first half of the furnace body, the gas can always blow to one side of the wafer; when the middle rod rotates to the second half, the air outlet on the other side can blow the passivation gas to the other side of the wafer, so as to realize the uniform passivation of each position of the wafer;

[0027] (3)In the present invention, when the middle rod is connected inside the furnace body, the end of the middle rod can be passed through the connecting collar, and supported by a number of support rods and supports. Finally, the furnace cover is closed, and the driving sleeve on the furnace cover is sleeved on the other end of the middle rod, and driven through the cooperation of the driving groove and the driving block, then the rotation of the entire passivation rack can be completed;

[0028] (4)In the present invention, the driving motor drives the driving worm and the driving worm wheel engaged therewith to rotate, thereby driving the rotation shaft and the driving sleeve to rotate, and then the driving rotation of the entire passivation rack can be realized. In addition, the heating wire is connected in a spiral shape in the cavity, which can heat the gas in the cavity, ensure that the incoming gas is always at a constant temperature, and improve the passivation effect;

[0029] (5)In the present invention, the passivation gas blown in can be repeatedly heated to ensure that the temperatures of all parts in the passivation furnace are the same. Therefore, the heating and passivation effects of the gas on all parts of the wafer are the same, avoiding uneven passivation due to uneven gas temperature. In addition, the two sides of the wafer can be heated and passivated simultaneously to ensure that the passivation quality of all parts of the wafer is the same. Description of the Drawings

[0030] Figure 1 is the overall structure diagram of Embodiment 1;

[0031] Figure 2 is the structure diagram of the passivation rack in Embodiment 1;

[0032] Figure 3 is Figure 2 the enlarged schematic view of A in

[0033] Wherein: 1, furnace body; 11, feed inlet; 12, furnace cover; 2, passivation rack; 21, middle rod; 22, fixing member; 221, fixing frame; 222, suction cup; 23, connecting rod; 3, connecting member; 31, connecting collar; 4, driving member; 41, rotating shaft; 42, driving motor; 43, driving worm wheel; 44, driving worm; 45, driving sleeve; 46, driving groove; 47, driving block; 5, air inlet assembly; 51, air wall; 52, cavity; 53, air outlet; 54, air inlet; 55, heating wire; 56, ring wall; 57, exhaust port. Detailed Embodiment

[0034] A polycrystalline double-sided battery passivation furnace provided in this embodiment has a structure as Figures 1-3 shown, including a furnace body 1, a feed inlet 11 opened at one end of the furnace body 1, and a furnace cover 12 covering the feed inlet 11. Inside the furnace body 1, there is provided

[0035] The passivation rack 2 includes a plurality of fixing members 22 for connecting wafers. The wafers are connected to the passivation rack 2 around the central axis of the passivation rack 2. The passivation rack 2 includes an intermediate rod 21. The center position at the bottom of the furnace body 1 is matched with the intermediate rod 21. When the passivation rack 2 is connected to the furnace body 1, the intermediate rod 21 is rotatably connected to the bottom end of the furnace body 1;

[0036] As Figures 1-3 shown, a connecting member 3 is provided in the furnace body 1, which is arranged at the center position of the bottom of the furnace body 1 for sleeving the intermediate rod 21 and connecting the end of the intermediate rod 21; A plurality of connecting rods 23 arranged in a straight line are provided on the intermediate rod 21. The end of the connecting rod 23 is rotatably connected with a fixing frame 221. A plurality of suction cups 222 arranged around the center line are provided on the inner side surface of the fixing frame 221. The suction cups 222 are correspondingly arranged on the side surface of the wafer. The two sides of the fixing frame 221 are eccentrically rotatably connected to the connecting rods 23 on both sides.

[0037] As Figures 1-3 shown, the connecting member 3 includes a connecting collar 31 formed at the center position of the inner bottom surface of the furnace body 1. When the passivation rack 2 is connected, the intermediate rod 21 is sleeved and rotatably connected in the connecting collar 31. A plurality of support rods perpendicular to the inner side wall of the furnace body 1 are provided in the furnace body 1. The end of the support rod is fixed with a semi-circular support for supporting the intermediate rod 21. The support rod is located at the interval position of the fixing member 22.

[0038] As Figures 1-3 shown, a driving member 4 is provided in the furnace body 1, which is arranged at the position corresponding to the end of the intermediate rod 21 on the furnace cover 12. The intermediate rod 21 is sleeved and connected in the driving member 4 to drive the intermediate rod 21 to rotate; The driving member 4 includes a rotating shaft 41 rotatably connected to the furnace cover 12 and penetrating through the furnace cover 12. A driving motor 42 is fixed on the top of the furnace cover 12. A driving worm wheel 43 is coaxially fixed on the rotating shaft 41. A driving worm 44 is formed on the output shaft of the driving motor 42. The driving worm 44 meshes with the driving worm wheel 43.

[0039] As Figures 1-3 shown, a driving sleeve 45 is fixed on a section of the rotating shaft 41 located in the furnace body 1. A plurality of driving grooves 46 arranged around the center line of the driving sleeve 45 are formed on the inner side wall of the driving sleeve 45. A plurality of driving blocks 47 corresponding to the driving grooves 46 are formed at the end of the intermediate rod 21. When connected, the driving blocks 47 are embedded in the driving grooves 46.

[0040] As Figures 1-3As shown in the figure, an air inlet assembly 5 is provided inside the furnace body 1, which includes an air wall 51 connected to the inner wall of the furnace body 1. A cavity 52 for accommodating gas is formed between the air wall 51 and the inner wall of the furnace body 1. One side of the air wall 51 is connected to the bottom of the furnace body 1, and a number of linearly arranged air outlets 53 are provided on the air wall 51. An air inlet 54 communicating with the cavity 52 is provided on the bottom of the furnace body 1; a heating wire 55 coiled in the cavity 52 is further provided in the cavity 52. The heating wire 55 is connected in the cavity 52 in a cylindrical spiral shape, and the furnace cover 12 and the furnace body 1 are connected and sealed by a flange.

[0041] As Figures 1-3 shown in the figure, the air outlets 53 are distributed on the air wall 51 in two rows, and the two rows of air outlets 53 are arranged oppositely for blowing gas to the wafer. One side of the air wall 51 connected to the bottom surface of the furnace body 1 forms an annular wall 56 in a ring shape, and the air inlet 54 communicates with the area of the annular wall 56. An exhaust port 57 is further provided on the bottom surface of the furnace body 1 for discharging the gas in the furnace body 1.

[0042] During operation, the operator connects a number of wafers to the passivation rack 2, sends the passivation rack 2 into the passivation furnace from the feed port 11 of the furnace body 1. The middle rod 21 of the passivation rack 2 cooperates with the connecting member 3, and then closes the furnace cover 12 on the feed port 11, so that the passivation rack 2 can be integrally connected in the passivation furnace to complete the passivation process of the wafer; during the passivation process, the air inlet 54 of the air inlet assembly 5 continuously blows passivation gas into the cavity 52 inside the air wall 51, and at the same time, the heating wire 55 in the cavity 52 continuously heats the passivation gas to a preset temperature. Then, the passivation gas is blown to the wafer from the air inlet 54. At this time, the driving member 4 drives the middle rod 21 to rotate, and a number of wafers on the passivation rack 2 can receive the blowing of passivation gas in different directions by rotating, so as to ensure that the passivation effects of all parts of the wafer are the same and improve the uniformity of wafer passivation.

[0043] The present invention can repeatedly heat the blown passivation gas to ensure that the temperatures of all parts in the passivation furnace are the same. Therefore, the heating and passivation effects of the gas on all parts of the wafer are the same, avoiding uneven passivation due to uneven gas temperature. In addition, the two sides of the wafer can be heated and passivated simultaneously, ensuring that the passivation quality of all parts of the wafer is the same.

[0044] In addition to the above embodiments, the present invention can also have other implementation manners. All technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present invention.

Claims

1. A polycrystalline double-sided battery passivation furnace, comprising a furnace body (1), a feed inlet (11) opened at one end of the furnace body (1), and a furnace cover (12) covering the feed inlet (11), characterized in that: Inside the furnace body (1), there is a passivation rack (2), including several fixing parts (22) for connecting wafers. The wafers are connected to the passivation rack (2) around the central axis of the passivation rack (2). The passivation rack (2) includes an intermediate rod (21). The center position at the bottom of the furnace body (1) is matched with the intermediate rod (21). When the passivation rack (2) is connected inside the furnace body (1), the intermediate rod (21) is rotatably connected to the bottom end of the furnace body (1); a connecting part (3), arranged at the center position of the bottom of the furnace body (1), for sleeving the intermediate rod (21) and connecting the end of the intermediate rod (21); a driving part (4), arranged at the position corresponding to the end of the intermediate rod (21) on the furnace cover (12). The intermediate rod (21) is sleeved and connected inside the driving part (4) to drive the intermediate rod (21) to rotate; an air inlet assembly (5), including an air wall (51) connected to the inner wall of the furnace body (1). A cavity (52) for accommodating gas is formed between the air wall (51) and the inner wall of the furnace body (1). One side of the air wall (51) is connected to the bottom of the furnace body (1). A number of linearly arranged air outlet openings (53) are formed on the air wall (51). An air inlet (54) communicating with the cavity (52) is formed on the bottom of the furnace body (1); Inside the cavity (52), there is also a heating wire (55) coiled inside the cavity (52); The driving part (4) includes a rotating shaft (41) rotatably connected to the furnace cover (12) and penetrating through the furnace cover (12). A driving motor (42) is fixed on the top of the furnace cover (12). A driving worm wheel (43) is coaxially fixed on the rotating shaft (41). A driving worm (44) is formed on the output shaft of the driving motor (42). The driving worm (44) meshes with the driving worm wheel (43); A driving sleeve (45) is fixed on a section of the rotating shaft (41) located inside the furnace body (1). A number of driving grooves (46) arranged around the center line of the driving sleeve (45) are formed on the inner side wall of the driving sleeve (45). A number of driving blocks (47) corresponding to the driving grooves (46) are formed at the end of the intermediate rod (21). When connecting, the driving blocks (47) are embedded in the driving grooves (46).

2. A passivation furnace for polycrystalline double-sided cells according to claim 1, characterized in that: A number of linearly arranged connecting rods (23) are arranged on the intermediate rod (21). A fixing frame (221) is rotatably connected to the end of the connecting rod (23). A number of suction cups (222) arranged around the center line are arranged on the inner side surface of the fixing frame (221). The suction cups (222) are correspondingly arranged on the side surface of the wafer. The two sides of the fixing frame (221) are eccentrically rotatably connected to the two sides of the connecting rod (23).

3. A passivation furnace for polycrystalline double-sided batteries according to claim 1, characterized in that: The connecting part (3) includes a connecting collar (31) formed at the center position of the inner bottom surface of the furnace body (1). When the passivation rack (2) is connected, the intermediate rod (21) is sleeved and rotatably connected inside the connecting collar (31). A number of support rods perpendicular to the inner side wall of the furnace body (1) are arranged inside the furnace body (1). A semi-circular support is fixed at the end of the support rod for supporting the intermediate rod (21). The support rods are located at the interval positions of the fixing parts (22).

4. A passivation furnace for polycrystalline double-sided cells according to claim 1, characterized in that: The air outlets (53) are distributed in two rows on the air wall (51), and the two rows of air outlets (53) are arranged oppositely for blowing gas to the wafer. One side of the air wall (51) connecting the bottom surface of the furnace body (1) forms an annular wall (56) in a ring shape, and the air inlet (54) communicates with the area of the annular wall (56). An exhaust port (57) is also provided on the bottom surface of the furnace body (1) for discharging the gas in the furnace body (1).

5. A passivation furnace for a polycrystalline double-sided battery according to claim 1, characterized in that: The heating wire (55) is connected in the cavity (52) in a cylindrical spiral shape, and the furnace lid (12) and the furnace body (1) are connected and sealed through a flange.

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