A method for preparing a heterojunction battery

Abstract

The present invention relates to the field of battery preparation and discloses a method for preparing a heterojunction battery. The chain cleaning equipment used in the S2 chain cleaning step includes: a frame, a cleaning tank is provided on the frame, a chain conveyor is also provided on the frame, a correction mechanism is provided on the frame, and the correction mechanism is used to correct the position of a carrier on the chain conveyor; the carrier is located on the chain conveyor and is used to carry multiple silicon wafers to be cleaned, and multiple slots are provided on the carrier. A rotation mechanism is provided at the bottom of the slot, and the rotation mechanism is used to adjust the silicon wafers to be cleaned in the slot; the present invention provides a rotation mechanism, so that when entering each cleaning tank, the rotation mechanism is used to rub and rotate the silicon wafers in the carrier slot, so that the dead angle area of the silicon wafer originally in contact with the bottom of the slot is rotated to other positions, so that the silicon wafer is exposed to the entire cleaning liquid, thereby achieving an all-round and dead-angle-free silicon wafer cleaning action.

Description

Technical Field

[0001] The present invention relates to the field of battery preparation, and in particular to a method for preparing a heterojunction battery. Background Art

[0002] With the continuous development of science and technology, solar cells have been widely used in people's daily lives and industry. In recent years, the production technology of solar cells has been continuously improved, the production cost has been continuously reduced, and the conversion efficiency has been continuously improved. The application of solar cell power generation has become increasingly widespread and has become an important energy source for electricity supply. Solar cells have become a priority for development in the world due to their advantages such as cleanliness, safety, and easy access. The current main development direction of solar cells is to reduce costs and increase power generation efficiency. At present, the conversion efficiency of heterogeneous cells has increased from 21.5% in 2015 to 24.5% in 2022, and is expected to become the next generation mainstream battery.

[0003] At present, most heterojunction solar cells have a cleaning process during the cutting, pickling, and texturing processes. Generally, heterojunction solar cells are cleaned by placing a basket of silicon wafers into a water washing tank, and then opening the bubbling and water purification valves to perform bubbling and overflow.

[0004] The cleaning process of silicon wafer surfaces significantly impacts the properties of solar cells. Silicon wafer cleaning equipment immerses silicon wafers in an acid or alkali bath, triggering a series of chemical reactions for cleaning. Currently, wafer carriers can be moved in and out of the wafer cleaning equipment. However, there are blind spots in the area where the wafers come into contact with the discharge basket, preventing efficient cleaning regardless of repeated cleaning cycles. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing a heterojunction battery to solve the technical problem that there is a cleaning dead corner in the area where the silicon wafer contacts the discharge basket, and no matter how many times the cleaning is performed, the battery cannot be cleaned well.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for preparing a heterojunction battery, comprising:

[0008] S1, silicon wafer cutting;

[0009] S2. Chain cleaning: The cut silicon wafers are placed on a carrier using a chain cleaning device. The silicon wafers are then placed in a potassium hydroxide cleaning solution for cleaning. During the cleaning process, the rotation mechanism on the carrier is used to partially rotate the silicon wafers to expose the dead corners where the silicon wafers contact the carrier to the potassium hydroxide cleaning solution. The surface of the silicon wafers is then acid-washed to complete cleaning.

[0010] S3, chain gettering: phosphoric acid is used to form phosphosilicate glass on the surface of the silicon wafer at a set temperature to absorb metal impurities in the silicon wafer;

[0011] S4, cleaning and texturing: Using the anisotropic etching principle of alkali on silicon, a pyramid shape is formed on the surface of the silicon wafer to achieve the purpose of light trapping; at the same time, the RCA cleaning process is used to clean the surface of the silicon wafer to prepare for the next step of coating;

[0012] S5, PEVCD coating: Using the excellent passivation effect of amorphous silicon, intrinsic amorphous silicon thin film and doped amorphous silicon thin film are deposited on the surface of the silicon wafer to form a PN junction;

[0013] S6, PVD coating: depositing TCO transparent conductive oxide film on the surface of the battery;

[0014] S7, screen printing: Use a fixed screen pattern to print silver paste on the front and back of the battery. After curing, a circuit is formed to draw out the current generated by the battery.

[0015] S8, testing and sorting: testing the solar cells, testing the electrical performance parameters of the solar cells, and sorting them according to the set standards;

[0016] S9. Packaging and warehousing: Pack, bundle and warehouse the solar cells of different grades according to the predetermined quantity and color.

[0017] Furthermore, the chain cleaning equipment used in S2 includes: a frame, a cleaning tank is provided on the frame, a chain conveyor is also provided on the frame, a correction mechanism is provided on the frame, and the correction mechanism is used to correct the position of the carrier on the chain conveyor; the carrier is located on the chain conveyor and is used to carry multiple silicon wafers to be cleaned, and multiple slots are provided on the carrier, and a rotation mechanism is provided at the bottom of the slots, and the rotation mechanism is used to adjust the silicon wafers to be cleaned in the slots.

[0018] Furthermore, the carrier is configured as a perforated structure, the rotation mechanism includes a rubbing bar, the rubbing bar is slidably connected to a slide groove provided on the bottom surface of the carrier, the slide groove is connected to the slot, and the upper surface of the rubbing bar is provided with a plurality of flexible teeth;

[0019] A plurality of sleeve shells are provided on one side of the carrier, and the positions of the sleeve shells are arranged in one-to-one correspondence with the slots. A coil spring is connected inside the sleeve shell, and one end of the coil spring is fixedly connected to the end of the rubbing bar. The other ends of the plurality of rubbing bars are fixedly connected to the roller, and both ends of the roller are rotatably connected to the carrier, and one of the rollers is driven by a driving member.

[0020] Furthermore, the correction mechanism includes: a connecting frame, both ends of the connecting frame are movably connected to the frame, two connecting frames are symmetrically arranged, each connecting frame is provided with a group of correction wheels, the top of the correction wheel is rotatably connected to the connecting frame through a rotating shaft, a group of sprockets are fixed on the top of the rotating shaft, and the multiple sprockets are driven by a chain, one of the sprockets is connected to the driving motor, the length of the rotating shaft is set according to the matching of the cleaning tank, and the spacing value of the two connecting frames on the side where the carrier enters is greater than the spacing value on the side where the carrier leaves.

[0021] Furthermore, the driving component is a waterproof servo motor, which is fixed on the side wall of the carrier and is transmission-connected to one end of the roller.

[0022] Furthermore, the driving member includes a gear, and gears are fixedly connected to both ends of the roller. A rack is provided on the wall of the cleaning tank, and the teeth on the rack are arranged at multiple intervals. The rack is higher than the upper surface of the chain conveyor and can engage with the gear. The rack is located below the correction wheel, and a groove is provided on the top of the flexible tooth portion, and a number of protrusions are evenly arranged on the concave surface of the groove.

[0023] Furthermore, expansion plates are provided on both sides of the slot, the top of the expansion plates is fixed on the top wall of the slide slot, the expansion plates are arranged into a U-shaped structure, the outer diameter of the U-shaped structure is larger than the slot diameter of the groove, and the outer diameter of the expansion plate on the side facing the coil spring is smaller than the outer diameter of the other side of the expansion plate.

[0024] Furthermore, elastic clamping strips are installed on both sides of the slot, the diameter of the middle area of the slot bottom is smaller than the diameter value of other areas of the slot bottom, and the spacing between the elastic clamping strips is gradually reduced from top to bottom.

[0025] Furthermore, a plurality of cams are axially arranged on one side of the gear facing the carrier, and the cams are arranged in an arc-shaped structure. A plurality of groups of support blocks are arranged on the side wall of the cleaning tank, and each group of support blocks is provided with two support blocks. The support blocks are opposite to the area of the rack having the teeth. A strike hammer is slidably connected between the two support blocks, and the strike hammer is connected to the end of the piston rod of the piston cylinder. The piston cylinder is fixed on the side wall of the cleaning tank, and a one-way nozzle is provided at one end of the piston cylinder, and a one-way fluid replenishment port is provided at the other end.

[0026] Furthermore, a plurality of toggle assemblies are inserted in the middle position of the chain conveyor, and the toggle assemblies are used to toggle the upper and lower layers of the chain conveyor. The toggle assembly includes a toggle rod, and both ends of the toggle rod are fixedly connected to a rocker rod, and the other end of the rocker rod is rotatably mounted on the groove wall of the cleaning tank through a No. 1 torsion spring. An eccentric wheel is connected to the top of the toggle rod, and the eccentric wheel is rotatably mounted on the groove wall of the cleaning tank through a No. 2 torsion spring. The upper half of the eccentric wheel in the long axis direction is located on the rotation path of the arc cam. A support plate is provided in the middle of the toggle rod, and a plurality of support springs are fixedly provided on the bottom surface of the support plate, and an impact block is fixed on the bottom surface of the support spring.

[0027] Beneficial effects of the present invention:

[0028] (1) The present invention sets up a rotation mechanism, so that when entering each cleaning tank, the rotation mechanism is used to rub and rotate the silicon wafer in the carrier slot, so that the dead angle area where the silicon wafer originally contacts the bottom of the slot is rotated to other positions, thereby being exposed to the entire cleaning liquid, thereby achieving an all-round and dead-angle-free silicon wafer cleaning action.

[0029] (2) After entering the cleaning tank, the present invention starts the driving member to drive the roller on one side of the carrier to rotate, and the roller drives the connected rubbing bar to wind, and the traction provided by the winding of the roller is used to pull the rubbing bar, and the flexible teeth on the top of the rubbing bar rub with the bottom of the silicon wafer in the slot, thereby forcibly rubbing the silicon wafer to rotate until the original bottom area of the silicon wafer is rotated to a certain angle and exposed to the cleaning liquid. At this time, the driving member stops driving, and the roller that has lost the driving force pulls the rubbing bar to quickly reset under the restoring force of the coil spring. The rubbing effect of the rubbing bar during the reset is used to allow the original bottom of the silicon wafer after rotation to return to the bottom area, and the left and right relative sliding of the rubbing bar is used to achieve the effect of reciprocating rubbing of the silicon wafer rotation, thereby achieving the rotation of the bottom of the silicon wafer, so that it is completely exposed to the cleaning liquid to achieve the purpose of comprehensive cleaning effect;

[0030] (3) The present invention utilizes a gear fixed at the end of the roller to mesh with a rack pre-matched on the side wall of the cleaning tank, and utilizes the transmission effect of the gear rack to rub the gear to rotate, and the gear drives the roller to rotate, and the roller achieves the purpose of winding the rubbing strip. Through the transmission mechanism of the gear rack, the power of the chain conveyor can be used to realize the power supply of the driving part, and there is no need to set up a separate power source, which can achieve the purpose of saving costs and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below with reference to the accompanying drawings.

[0032] Figure 1 is a process flow chart of the present invention;

[0033] Figure 2It is a structural schematic diagram of the chain cleaning equipment in the present invention;

[0034] Figure 3 Schematic diagram of the structure of the carrier in the present invention;

[0035] Figure 4 is a schematic top view of the carrier of the present invention;

[0036] Figure 5 Schematic diagram of the structure of the slot expansion plate and the flexible tooth portion in the present invention;

[0037] Figure 6 Schematic diagram of the positional relationship between the cam and the impact hammer in the present invention;

[0038] Figure 7 for Figure 6 Schematic diagram of the three-dimensional structure;

[0039] Figure 8 It is a schematic diagram of the three-dimensional structure of the support plate, support spring and impact block.

[0040] Description of the drawings: 1. Frame; 2. Correction mechanism; 21. Connecting frame; 22. Correction wheel; 23. Sprocket; 24. Chain drive; 3. Carrier; 4. Slot; 5. Rotation mechanism; 51. Rubbing bar; 52. Slide; 53. Flexible tooth portion; 54. Housing; 55. Coil spring; 56. Roller; 57. Driving member; 571. Gear; 572. Rack; 573. Groove; 574. Protrusion; 575. Slot expansion plate; 5 76. U-shaped structure; 577. Elastic clamping strip; 6. Cleaning tank; 7. Cam; 8. Support block; 9. Impact hammer; 10. Piston rod; 11. Piston cylinder; 12. One-way nozzle; 13. One-way refill port; 14. Toggle assembly; 141. Toggle rod; 142. Rocker arm; 143. Torsion spring No. 1; 144. Eccentric wheel; 145. Torsion spring No. 2; 146. Support plate; 147. Support spring; 148. Impact block. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] See also Figures 1-8 As shown, the present invention is a method for preparing a heterojunction battery, comprising:

[0043] S1. Silicon wafer cutting: The purchased silicon wafers are adjusted using high-precision galvanometers and linear motors, and a refrigerant-free method (most on the market use water) is used to better protect the N-type silicon wafer film layer to complete the silicon wafer cutting.

[0044] S2. Chain cleaning: The cut silicon wafers are placed on carrier 3 using a chain cleaning device. The silicon wafers are then placed in a potassium hydroxide cleaning solution for cleaning. During the cleaning process, the rotation mechanism 5 on the carrier 3 partially rotates the silicon wafers to expose the dead corners where the silicon wafers contact the carrier 3 to the potassium hydroxide cleaning solution. The silicon wafer surfaces are then acid-washed to complete cleaning.

[0045] S3, chain gettering: phosphoric acid is used to form phosphosilicate glass on the surface of the silicon wafer at a set temperature to absorb metal impurities in the silicon wafer;

[0046] S4, cleaning and texturing: Using the anisotropic etching principle of alkali on silicon, a pyramid shape is formed on the surface of the silicon wafer to achieve the purpose of light trapping; at the same time, the RCA cleaning process is used to clean the surface of the silicon wafer to prepare for the next step of coating;

[0047] S5, PEVCD coating: Utilizes the excellent passivation effect of amorphous silicon to deposit intrinsic amorphous silicon thin films and doped amorphous silicon thin films on the surface of the silicon wafer, thereby forming a PN junction; the process mainly uses RF power to excite silane (Si H4), hydrogen (H2) and other process gases into a plasma state, and react with each other, and finally deposited in the form of a thin film on the surface of the silicon wafer

[0048] S6, PVD coating: Deposit TCO transparent conductive oxide film on the surface of the battery; the process mainly uses the principle of magnetron sputtering to deposit TCO material in the form of a thin film on the surface of the battery to achieve the functions of conductivity, anti-reflection and protection of the amorphous silicon film.

[0049] S7, screen printing: Use a fixed screen pattern to print silver paste on the front and back of the battery. After curing, a circuit is formed to draw out the current generated by the battery.

[0050] S8, test and sorting: Test the solar cells under standard IV test conditions, test the electrical performance parameters of the solar cells, and sort them according to the set standards;

[0051] S9. Packaging and warehousing: Pack, bundle and warehouse the solar cells of different grades according to the predetermined quantity and color.

[0052] Furthermore, the chain cleaning equipment used in S2 includes: a frame 1, a cleaning tank 6 is provided on the frame 1, a chain conveyor is also provided on the frame 1, a correction mechanism 2 is provided on the frame 1, and the correction mechanism 2 is used to correct the position of the carrier 3 on the chain conveyor; the carrier 3 is located on the chain conveyor and is used to carry multiple silicon wafers to be cleaned, and multiple slots 4 are provided on the carrier 3, and a rotation mechanism 5 is provided at the bottom of the slot 4, and the rotation mechanism 5 is used to adjust the silicon wafers to be cleaned in the slot 4.

[0053] The present invention sets up a rotation mechanism 5, so that when entering each cleaning tank 6, the rotation mechanism 5 is used to rub and rotate the silicon wafer in the slot 4 of the carrier 3, so that the dead angle area where the silicon wafer originally contacts the bottom of the slot 4 is rotated to other positions, thereby being exposed to the entire cleaning liquid, thereby achieving an all-round and dead-angle-free silicon wafer cleaning action; it should be noted that the chain conveyor is an existing technology, which can transport the silicon wafers to different cleaning tanks 6 in turn for corresponding cleaning, and will not be elaborated here.

[0054] Furthermore, the carrier 3 is configured as a perforated structure, and the rotation mechanism 5 includes a rubbing bar 51, which is slidably connected to a slide groove 52 provided on the bottom surface of the carrier 3, and the slide groove 52 is connected to the slot 4. The upper surface of the rubbing bar 51 is provided with a plurality of flexible teeth 53;

[0055] A plurality of sleeve shells 54 are provided on one side of the carrier 3. The positions of the sleeve shells 54 are arranged in a one-to-one correspondence with the slots 4. A coil spring 55 is connected to the sleeve shell 54. One end of the coil spring 55 is fixedly connected to the end of the rubbing bar 51. The other ends of the plurality of rubbing bars 51 are fixedly connected to the roller 56. The two ends of the roller 56 are rotatably connected to the carrier 3. One of the rollers 56 is driven by a driving member 57. In this embodiment, by setting the carrier 3 into a perforated structure, the cleaning liquid can contact the silicon wafers in the slots 4 to the greatest extent, so as to achieve the best silicon wafer cleaning effect and reduce the impact on the performance of the finished battery. Specifically, after entering the cleaning tank 6, the driving member 57 is started to drive the roller 56 on one side of the carrier 3 to rotate. The roller 56 drives the connected rubbing bar 51 to wind around. The traction provided by the winding of the roller 56 is used to pull the rubbing bar 51. The flexible teeth 53 at the top of the rubbing bar 51 rub against the bottom of the silicon wafer in the slot 4, thereby forcing The silicon wafer is rubbed and rotated until the original bottom area of the silicon wafer is rotated to a certain angle and exposed to the cleaning liquid. At this time, the driving part 57 stops driving, and the roller 56 that has lost the driving force pulls the rubbing bar 51 to quickly reset under the restoring force of the coil spring 55. The rubbing effect of the rubbing bar 51 during the reset is used to allow the original bottom of the silicon wafer after rotation to return to the bottom area. The left and right relative sliding of the rubbing bar 51 is used to achieve the effect of reciprocating rubbing of the silicon wafer rotation, thereby realizing the rotation of the bottom of the silicon wafer, so that it is completely exposed to the cleaning liquid to achieve the purpose of comprehensive cleaning effect.

[0056] Furthermore, the correction mechanism 2 includes: a connecting frame 21, both ends of the connecting frame 21 are movably connected to the frame 1, two connecting frames 21 are symmetrically arranged, and each connecting frame 21 is provided with a group of correction wheels 22, and the top of the correction wheel 22 is rotatably connected to the connecting frame 21 through a rotating shaft, and a sprocket 23 is fixed to the top of a group of the rotating shafts, and a chain drive 24 is passed between multiple sprockets 23, one of the sprockets 23 is connected to the driving motor, and the length of the rotating shaft is set to match the cleaning tank 6, and the spacing value of the two connecting frames 21 on the side where the carrier 3 enters is greater than the spacing value on the side where the carrier 3 leaves. In this embodiment, the carrier 3 is clamped in the middle by the correction wheels 22 on both sides, so that the carrier 3 is always located in the middle area of the chain conveyor, ensuring the safety of the carrier 3 and the silicon wafer; specifically, one of the sprockets 23 is driven to rotate by a driving motor, and then the left and right sprockets 23, the rotating shaft and the correction wheel 22 on the same side are driven to rotate by the chain transmission 24, and the sprockets 23 on both sides convey the carrier 3 in the same direction, ensuring the safety of the carrier 3.

[0057] Furthermore, the driving member 57 is a waterproof servo motor, which is fixed to the side wall of the carrier 3 and is in driving connection with one end of the roller 56. In this embodiment, one embodiment of the driving member 57 is provided. When the driving member 57 is a waterproof servo motor, the driving force provided by the waterproof servo motor can easily drive the roller 56 to rotate, thereby winding the multiple rubbing strips 51, which is convenient and fast. Moreover, after leaving the cleaning tank 6, the rubbing silicon wafer can also be rotated, using the reciprocating rotational force to accelerate the shedding of droplets on the silicon wafer, preventing surface damage caused by the long-lasting adhesion of acidic solutions and alkaline solutions.

[0058] Furthermore, the driving member 57 includes a gear 571, and the two ends of the roller 56 are fixedly connected to the gears 571. A rack 572 is provided on the groove wall of the cleaning tank 6, and the teeth on the rack 572 are arranged in multiple sections at intervals. The rack 572 is higher than the upper surface of the chain conveyor and can engage with the gear 571. The rack 572 is located below the correction wheel 22. A groove 573 is provided on the top of the flexible tooth portion 53, and a number of protrusions 574 are evenly arranged on the concave surface of the groove 573.

[0059] Furthermore, expansion plates 575 are provided on both sides of the slot 4. The top of the expansion plates 575 is fixed to the top wall of the slide 52. The expansion plates 575 are arranged in a U-shaped structure 576. The outer diameter of the U-shaped structure 576 is larger than the groove diameter of the groove 573, and the outer diameter of the expansion plate 575 on the side facing the coil spring 55 is smaller than the outer diameter of the other side of the expansion plate 575. In this embodiment, another embodiment of the driving member 57 is provided, in which a gear 571 fixed to the end of the roller 56 is engaged with a rack 572 pre-matched and provided on the side wall of the cleaning tank 6. The gear 571 and the rack 572 are driven to rotate the transmission gear 571, which drives the roller 56 to rotate. The roller 56 then winds the rubbing strip 51. Through the transmission mechanism of the gear 571 and the rack 572, the power supply of the driving member 57 can be realized by utilizing the power of the chain conveyor, eliminating the need for a separate power source, thereby saving costs and reducing energy consumption.

[0060] At the same time, the chain conveyor drives the carrier 3 to move back and forth within the cleaning tank 6 over a short distance, so that the gear 571 and the rack 572 can engage and drive the roller 56 to rotate forward and reverse, thereby pulling and relaxing the rubbing bar 51. In conjunction with the automatic contraction of the coil spring, the rubbing bar 51 can move back and forth, causing the rubbing silicon wafer to rotate back and forth, so that it is fully exposed to the cleaning liquid and achieves the purpose of thorough cleaning. Since the rack 572 is only set in the cleaning tank 6, the rotary mechanism is idle in other states to prevent interference with the normal conveying process.

[0061] Furthermore, a groove 573 is provided on the top of the flexible tooth portion 53, and the cooperation of the groove 573 and the convex particle 574 is used to clamp the bottom area of the silicon wafer. In the process of the flexible protrusion continuously rubbing the silicon wafer to rotate, on the one hand, the expansion slot plate 575 on the right side is smaller on the right and larger on the left, and just enters the flexible tooth portion 53 that is about to contact the silicon wafer. The structure of the expansion slot plate 575 is used to expand the groove 573 to the maximum, which is convenient for the silicon wafer to fall into the groove 573 and partially clamp the silicon wafer under the action of its own elastic force, thereby preventing the silicon wafer from escaping from the bottom of the slot 4 when the flexible protrusion rubs the silicon wafer to rotate, and preventing the adjacent silicon wafers from tilting and colliding, thereby ensuring the safety of the silicon wafer; on the other hand, the expansion slot plate 575 on the left side can enter the flexible tooth portion 53 of the pre-detached silicon wafer, and the expansion slot plate 575 is used to press the groove 573 again. The flexible tooth portion 53 is stretched out for the second time, thereby separating the flexible tooth portion 53 from the silicon wafer, thereby avoiding the influence of the flexible protrusion in the non-working state on the rotational action of the flexible tooth portion 53 in the working state rubbing the silicon wafer; through the above-mentioned structural setting, on the one hand, the groove 573 and the expansion groove plate 575 are matched with each other, and the clamping effect of rubbing the silicon wafer is achieved when contacting with the silicon wafer. When the silicon wafer is about to be separated, the passive expansion is completely separated from the silicon wafer to prevent the influence on the subsequent rubbing action of the flexible protrusion; on the other hand, the transmission mechanism of the gear 571 and the rack 572 is used to effectively make secondary use of the action of the chain conveyor, which can not only realize the transportation of the carrier 3 and the silicon wafer, but also can drive the passive rubbing rotation mechanism 5 to work through the gear 571 and the rack 572, thereby realizing the organic combination and action linkage between the two, which is convenient and fast, and the cleaning effect is also stronger.

[0062] Furthermore, elastic clamping strips 577 are installed on both sides of the slot 4. The diameter of the middle area at the bottom of the slot 4 is smaller than the diameter of other areas at the bottom of the slot 4. The spacing between the elastic clamping strips 577 is gradually reduced from top to bottom. By setting the elastic clamping strips 577, the silicon wafer placed in the slot 4 is auxiliaryly clamped by utilizing its own elastic deformation ability. At the same time, by utilizing the smaller diameter of the middle area at the bottom of the slot 4, the flexible teeth 53 are forced to squeeze toward the center when passing through the middle area at the bottom of the slot 4, thereby further clamping the silicon wafer. However, upon encountering the slot expansion plate 575, the flexible teeth 53 immediately separate from the silicon wafer, thereby always maintaining the clamping effect of some flexible protrusions on the silicon wafer, while the other flexible protrusions are completely separated from the silicon wafer.

[0063] A plurality of cams 7 are axially arranged on one side of the gear 571 facing the carrier 3, and the cams 7 are arranged in an arc structure. A plurality of groups of support blocks 8 are arranged on the side wall of the cleaning tank 6, and each group of support blocks 8 is provided with two. The support blocks 8 are opposite to the area with the teeth of the rack 572, and a hammer 9 is slidably connected between the two support blocks 8. The hammer 9 is connected to the end of the piston rod 10 of the piston cylinder 11, and the piston cylinder 11 is fixed on the side wall of the cleaning tank 6, and a one-way nozzle 12 is provided at one end of the piston cylinder 11, and a one-way fluid replenishment port 13 is provided at the other end. In the present invention, the cam 7 and the hammer 9 cooperate. When the rack 572 and the gear 571 are meshed, and the silicon wafer is in the process of twisting and rotating, the gear 571 further drives the arc-shaped cam 7 to intermittently push the hammer 9 upward. The intermittent upward movement of the hammer 9 forcibly squeezes the cleaning liquid in the piston cylinder 11 and sprays it out from the one-way nozzle 12, and then directly sprays it on the surface of the rotating silicon wafer. Through the above-mentioned structure, the present invention uses the gear 571 and the rack 572 to drive the rotation mechanism 5 to operate, while driving the piston cylinder 11 to compress and spray the cleaning liquid. On the one hand, the power of the chain conveyor can be used to drive the rotation mechanism 5 to drive the silicon wafer to rotate to achieve full exposure and thorough cleaning. On the other hand, the rotation of the gear 571 can be used to spray the cleaning liquid through the hammer 9, the piston cylinder 11 and the one-way nozzle 12 during the silicon wafer selection process, so that the cleaning liquid is sprayed directly onto the rotating silicon wafer, thereby achieving the purpose of further rinsing the bottom area of the silicon wafer. At the same time, the use of the cleaning liquid spraying when the silicon wafer is rotating increases the local fluidity of the cleaning liquid, further enhancing the cleaning effect of the silicon wafer.

[0064] Furthermore, a plurality of toggle assemblies 14 are inserted in the middle position of the chain conveyor, and the toggle assemblies 14 are used to toggle the upper and lower layers of the chain conveyor. The toggle assembly 14 includes a toggle rod 141, and both ends of the toggle rod 141 are fixedly connected to a rocker rod 142, and the other end of the rocker rod 142 is rotatably mounted on the groove wall of the cleaning tank 6 through a No. 1 torsion spring 143. An eccentric wheel 144 is connected to the top of the toggle rod 141, and the eccentric wheel 144 is rotatably mounted on the groove wall of the cleaning tank 6 through a No. 2 torsion spring 145. The upper half of the eccentric wheel 144 in the long axis direction is located on the rotation path of the arc cam 7. A support plate 146 is provided in the middle of the toggle rod 141, and a plurality of support springs 147 are fixedly provided on the bottom surface of the support plate 146, and an impact block 148 is fixed on the bottom surface of the support spring 147. During implementation, by setting up the toggle assembly 14, when the gear 571 and rack 572 are in meshing transmission, the arc-shaped cam 7 is used to pass through the eccentric wheel 144, thereby toggling the upper half of the eccentric wheel 144, allowing the eccentric wheel 144 to overcome the second torsion spring 145 and deflect. At this time, the long axis direction of the eccentric wheel 144 gradually changes from a vertical state to a horizontal state, leaving space for the toggle rod 141 below to swing upward, so under the action of the first torsion spring 143, the rocker rod 142 swings upward and always fits the eccentric wheel 144, so that the toggle rod 141 between the two rocker rods 142 swings up accordingly, thereby hitting the upper layer of the chain conveyor. On the one hand, the impact force is used to make the upper layer of the chain conveyor fluctuate, and then disturb the local cleaning fluid, allowing the cleaning fluid to flush the silicon wafer, achieving Further cleaning effect; on the other hand, after the cam 7 leaves the range of the eccentric wheel 144, the eccentric wheel 144 returns to its initial state under the reset action of the No. 2 torsion spring 145, thereby forcing the toggle rod 141 to swing down and reset. When the toggle rod 141 swings down and resets, the support spring 147 and the impact block 148 at the bottom just impact the lower surface of the chain conveyor, so that a local wave peak is formed on the surface of the chain conveyor, further strengthening the flow of the cleaning liquid at this location, which just flushes the silicon wafers on the carrier 3; at the same time, the upper and lower layers of the chain conveyor are intermittently toggled by the toggle component 14, and the conversion of the local wave peak posture is used to allow the impurities cleaned from the silicon wafers to fall from the upper and lower layers of the chain conveyor, preventing the impurities from accumulating and clumping on the chain conveyor, thus saving subsequent cleaning time.

[0065] The above is a detailed description of an embodiment of the present invention. However, the content described is only a preferred embodiment of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for preparing a heterojunction battery, characterized in that: include: S1, silicon wafer cutting; S2, chain cleaning; S3, chain absorption; S4, cleaning and velveting; S5, PEVCD coating; S6, PVD coating; S7, screen printing; S8, test and sorting; S9, packaging and warehousing; The chain cleaning device used in S2 comprises: a frame (1), a cleaning trough (6) is provided on the frame (1), a chain conveyor is further provided on the frame (1), a correction mechanism (2) is provided on the frame (1), and the correction mechanism (2) is used to correct the position of the carrier (3) on the chain conveyor; the carrier (3) is located on the chain conveyor and is used to carry a plurality of silicon wafers to be cleaned, a plurality of slots (4) are provided on the carrier (3), a rotation mechanism (5) is provided at the bottom of the slots (4), and the rotation mechanism (5) is used to adjust the silicon wafers to be cleaned in the slots (4); the carrier (3) is set as a perforated structure, and the rotation mechanism (5) includes a rubbing bar (51), the rubbing bar (51) is slidably connected to a slide groove (52) provided on the bottom surface of the carrier (3), the slide groove (52) is connected to the slots (4), and the upper surface of the rubbing bar (51) is provided with a plurality of flexible teeth (53); A plurality of sleeve shells (54) are provided on one side of the carrier (3), and the positions of the sleeve shells (54) are arranged in a one-to-one correspondence with the slots (4). A coil spring (55) is connected inside the sleeve shell (54), and one end of the coil spring (55) is fixedly connected to the end of the rubbing bar (51). The other ends of the plurality of rubbing bars (51) are fixedly connected to a roller (56). Both ends of the roller (56) are rotatably connected to the carrier (3), and one of the rollers (56) is driven by a driving member (57).

2. The method for preparing a heterojunction battery according to claim 1, wherein: The correction mechanism (2) comprises: a connecting frame (21), both ends of which are movably connected to the frame (1), two connecting frames (21) are symmetrically provided, each connecting frame (21) is provided with a group of correction wheels (22), the top of each correction wheel (22) is rotatably connected to the connecting frame (21) via a rotating shaft, a sprocket (23) is fixed to the top of each group of rotating shafts, a plurality of sprockets (23) are connected via a chain transmission (24), one of the sprockets (23) is connected to a driving motor, the length of the rotating shaft is set according to the matching of the cleaning tank (6), and the spacing value of the two connecting frames (21) on the side where the carrier (3) enters is greater than the spacing value on the side where the carrier (3) leaves.

3. The method for preparing a heterojunction battery according to claim 1, wherein: The driving member (57) is a waterproof servo motor, which is fixed on the side wall of the carrier (3) and is transmission-connected to one end of the rotating roller (56).

4. The method for preparing a heterojunction battery according to claim 3, wherein: The driving member (57) includes a gear (571), and the two ends of the roller (56) are fixedly connected to the gears (571). A rack (572) is provided on the groove wall of the cleaning groove (6), and the teeth on the rack (572) are arranged at intervals of multiple sections. The rack (572) is higher than the upper surface of the chain conveyor and can be engaged with the gear (571). The rack (572) is located below the correction wheel (22). A groove (573) is provided on the top of the flexible tooth portion (53), and a plurality of protrusions (574) are evenly arranged on the concave surface along the inner edge of the groove (573).

5. The method for preparing a heterojunction battery according to claim 4, wherein: An expansion plate (575) is provided on both sides of the slot (4), the top end of the expansion plate (575) is fixed on the top wall of the slide slot (52), and the expansion plate (575) is arranged into a U-shaped structure (576). The outer diameter of the U-shaped structure (576) is greater than the groove diameter of the groove (573), and the outer diameter of the expansion plate (575) on one side facing the coil spring (55) is smaller than the outer diameter of the other side of the expansion plate (575).

6. The method for preparing a heterojunction battery according to claim 5, wherein: Elastic clamping strips (577) are installed on both sides of the slot (4), the diameter of the middle area at the bottom of the slot (4) is smaller than the diameter of other areas at the bottom of the slot (4), and the spacing between the elastic clamping strips (577) is gradually reduced from top to bottom.

7. The method for preparing a heterojunction battery according to claim 4, wherein: A plurality of cams (7) are axially arranged on one side of the gear (571) facing the carrier (3), and the cams (7) are arranged in an arc-shaped structure. A plurality of groups of support blocks (8) are arranged on the side wall of the cleaning tank (6), and each group of support blocks (8) is provided with two. The support blocks (8) are opposite to the area having the teeth of the rack (572), and a striker (9) is slidably connected between the two support blocks (8). The striker (9) is connected to the end of the piston rod (10) of the piston cylinder (11), and the piston cylinder (11) is fixed on the side wall of the cleaning tank (6), and a one-way nozzle (12) is provided at one end of the piston cylinder (11), and a one-way liquid replenishing port (13) is provided at the other end.

8. The method for preparing a heterojunction battery according to claim 4, characterized in that: A plurality of toggle assemblies (14) are interspersed in the middle of the chain conveyor. The toggle assemblies (14) are used to toggle the upper and lower layers of the chain conveyor. The toggle assemblies (14) include a toggle rod (141). Both ends of the toggle rod (141) are fixedly connected to a rocker rod (142). The other end of the rocker rod (142) is rotatably mounted on the wall of the cleaning tank (6) via a torsion spring (143). An eccentric wheel (144) is connected to the top of the toggle rod (141), and the eccentric wheel (144) is rotatably mounted on the wall of the cleaning tank (6) through a No. 2 torsion spring (145). The upper half of the eccentric wheel (144) in the long axis direction is located on the rotation path of the arc cam (7). A support plate (146) is provided in the middle of the toggle rod (141), and a plurality of support springs (147) are fixedly provided on the bottom surface of the support plate (146), and an impact block (148) is fixed on the bottom surface of the support spring (147).

9. The method for preparing a heterojunction battery according to claim 1, wherein: The specific steps of the chain cleaning are as follows: using the chain cleaning equipment to place the cut silicon wafers onto the carrier (3), and then uniformly placing the silicon wafers into the potassium hydroxide cleaning solution for cleaning. During the cleaning process, the rotation mechanism (5) on the carrier (3) is used to partially rotate the silicon wafers, and then the surface of the silicon wafers is cleaned by pickling; the specific steps of the chain impurity absorption are to use phosphoric acid to form phosphorus silicon glass on the surface of the silicon wafer at a set temperature to absorb the metal impurities in the silicon wafer; the specific steps of the cleaning and texturing are to use the anisotropic etching principle of alkali on silicon to form a pyramid shape on the surface of the silicon wafer to achieve the purpose of light trapping; at the same time, the surface of the silicon wafer is cleaned by using the RCA cleaning process to prepare for the next step of coating; the P The specific steps of EVCD coating are to utilize the excellent passivation effect of amorphous silicon to deposit intrinsic amorphous silicon thin film and doped amorphous silicon thin film on the surface of silicon wafer, thereby forming a PN junction; the specific steps of PVD coating are to deposit TCO transparent conductive oxide film on the surface of the battery; the specific steps of screen printing are to use a fixed screen pattern to print silver paste on the front and back of the battery, and after curing, a circuit is formed to draw out the current generated by the battery; the specific steps of testing and sorting are to test the solar cells, test the electrical performance parameters of the solar cells, and classify them according to the set standards; the specific steps of packaging and warehousing are to package, pack and warehouse solar cells of different gears according to the established quantity and color.

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