Topcon battery based on double-layer printing technology and preparation technology

Abstract

The invention discloses a topcon cell based on a double-layer printing process and a preparation process, and relates to the technical field of solar cell production, and the preparation process comprises the steps of cleaning, texturing, tunneling oxide layer preparation, polycrystalline silicon layer deposition, diffusion and activation, high-temperature diffusion, silk-screen printing process and sintering and light injection treatment. A push-press structure and a push-back structure are arranged in the silk-screen printing process, the preparation process and equipment can reduce contact resistance, reduce electric energy loss and reduce contact loss by reducing the density, and the purpose of reducing the contact loss is achieved by combining two kinds of slurry with different characteristics and a printing mode. And in the silk-screen printing process, the printing precision quality is guaranteed, the utilization rate of the metal slurry and the printing efficiency are improved, and then the overall performance of the Topcon battery is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cell production, in particular to a preparation process of a topcon cell based on a double-layer printing process. BACKGROUND

[0002] With the continuous development of the photovoltaic industry, the requirements for the conversion efficiency, stability and cost control of solar cells are increasing, and the preparation process and screen printing process of Topcon cells as a kind of high-efficiency solar cell structure have always been the focus of research and improvement.

[0003] In the prior art, a TOPCon cell preparation method based on an LPCVD process with publication number CN120035259A first performs a first constant temperature operation after performing a first vacuumizing operation and a temperature rising operation on the furnace tube, and performs a second vacuumizing operation on the furnace tube during the constant temperature process. In this way, the duration of vacuumizing before oxygen is introduced into the furnace tube will be increased, so that the furnace tube can be cleaned more thoroughly, thereby ensuring the quality of the tunneling oxide layer formed by oxidation. Moreover, due to the increased duration of vacuumizing, the vacuum degree inside the furnace tube is higher, thereby also enhancing the adhesion of the furnace door, so that the leakage rate of the furnace tube is lower. In this way, the tunneling oxide layer and the polysilicon layer can be formed in a stable environment. Therefore, the above-mentioned TOPCon cell preparation method based on the LPCVD process can effectively improve the performance of the cell.

[0004] In the traditional Topcon cell preparation process, the metallization link has a key influence on the performance of the cell. The ohmic contact formed by the common silver paste printing has the problems of relatively high contact resistance and large power transmission loss, which affects the fill factor and output power of the cell and limits the improvement of the overall performance of the cell. Silver paste has good conductivity, but its cost is high. If copper paste with lower cost is used for metallization, copper and silicon are prone to adverse reactions, which leads to decreased stability and insufficient reliability of the cell.

[0005] As for the screen printing process, the existing printing equipment and methods also have some shortcomings. In the printing process, it is difficult to accurately control the contact angle and pushing force of the squeegee and the printing screen plate, which leads to unstable pushing of the metal paste, and the printing precision and quality are difficult to guarantee, resulting in poor accuracy and uniformity of the metal electrode pattern, which further affects the consistency of the cell performance. In addition, the sticking phenomenon of the metal paste on the squeegee is common, which not only causes waste of paste and increases production cost, but also affects the smooth progress of subsequent printing operations, reducing the utilization rate and printing efficiency of the metal paste. SUMMARY

[0006] The application aims to provide a preparation process of a topcon cell based on a double-layer printing process, and solve the following technical problems: the ohmic contact formed by common silver paste printing has a relatively high contact resistance and a large power transmission loss, which affects the fill factor and output power of the cell and limits the improvement of the overall performance of the cell; the silver paste has good conductivity, but its cost is high, and if copper paste with a lower cost is used for metallization, copper and silicon are prone to adverse reactions, resulting in decreased stability and insufficient reliability of the cell.

[0007] The object of the application can be achieved by the following technical solutions:

[0008] A preparation process of a topcon cell based on a double-layer printing process, comprising the following steps:

[0009] S1: cleaning;

[0010] Alkaline cleaning: using a sodium hydroxide alkaline solution to remove organic impurities and grease on the surface of the silicon wafer, through chemical reaction, the organic matter is decomposed and separated from the surface of the silicon wafer, and part of the metal impurities can also be removed;

[0011] Deionized water rinsing: the silicon wafer after alkaline cleaning is rinsed with deionized water to remove the residual alkaline solution and reaction products on the surface;

[0012] S2: texturing;

[0013] Alkaline texturing: using an alkaline solution such as sodium hydroxide or potassium hydroxide, adding an appropriate amount of additives such as surfactants, to control the formation of the texture structure, the solution concentration is generally between 0.5%-5%, the type and amount of the additive are adjusted according to the material of the silicon wafer and the required texture morphology, after texturing, the silicon wafer is rinsed with deionized water to remove the residual alkaline solution and reaction products on the surface, and then dried to ensure that the surface of the silicon wafer is dry and free of water stains;

[0014] S3: preparation of a tunnel oxide layer;

[0015] Dry oxygen oxidation: placing the silicon wafer in a high-temperature oxidation furnace and oxidizing in a dry oxygen atmosphere;

[0016] S4: polysilicon layer deposition;

[0017] Low-pressure chemical vapor deposition: using silane as the main source gas, thermal decomposition reaction is carried out at low temperature and low pressure to generate a polysilicon thin film;

[0018] S5: diffusion and activation;

[0019] Phosphorus implantation: phosphorus implantation is performed using an ion implanter. The appropriate implantation energy and dose need to be selected to ensure that the phosphorus ions can penetrate the polysilicon layer and enter the silicon wafer substrate to form a P / N+ type polysilicon layer;

[0020] Activation annealing: after implantation, activation annealing is required to make the implanted phosphorus ions diffuse in the silicon wafer and form effective electrically active doping. Activation annealing is usually performed in a tube furnace or a rapid thermal annealing device;

[0021] S6: high temperature diffusion;

[0022] Common phosphorus diffusion sources include phosphoric acid or phosphorus oxychloride. The diffusion source is placed in a quartz boat or graphite boat and placed in a diffusion furnace together with the silicon wafer for diffusion;

[0023] S7: screen printing process;

[0024] The first printing is a burn-through silver paste dot printing: a burn-through silver paste is selected as the printing material, and printing is performed through a printing structure. The burn-through silver paste has high conductivity and good burn-through capability, and can penetrate the polysilicon layer and tunnel through the oxide layer during high-temperature sintering, forming a good ohmic contact with the silicon wafer substrate;

[0025] The second printing is a non-burn-through low-temperature base metal paste printing: the metal paste is a copper paste. The copper paste has good conductivity. The copper paste is specially treated and formulated, and appropriate additives and passivation layers are added to inhibit the interaction between copper and silicon.

[0026] S8: sintering and light injection treatment;

[0027] Sintering treatment can form a low-resistance ohmic contact between the metal paste and the silicon wafer. The precise setting of sintering temperature and time is crucial to ensure good contact between the metal and the silicon, and to prevent damage to the battery structure and performance caused by high temperature. The final light injection treatment can further improve the performance and stability of the battery, optimize the transmission and collection efficiency of the carriers, and is the last link to improve the overall performance of the battery.

[0028] Preferably, in S1, the concentration of sodium hydroxide solution is 1%-10%, the temperature is 60-80℃, and the time is 5-15min; in S2, the texturing temperature is 70-90℃; in S3, the oxidation temperature is generally 800-1200℃; in S5, the implantation energy is generally 10-100keV, the dose is 1*10 14 -1*10 15 cm -2 , the annealing temperature is 800-1000℃; in S6, the diffusion temperature is 800-1000℃; in S8, the peak temperature of the sintering furnace is 800-950℃.

[0029] Preferably, in the S4, the low-temperature environment is 500-700 DEG C, the low-pressure environment is 10-500 pa, and the reaction equation is: SiH4→Si+2H2.

[0030] Another object of the present application is to provide a printing device for a Topcon battery double-layer printing process, comprising a support disc, a circular groove is formed on the top side of the support disc, a rotating disc is rotatably installed in the circular groove, a plurality of annularly arranged receiving grooves are formed on the top side of the rotating disc, a printing member is arranged on the side of the support disc and above the rotating disc;

[0031] The printing screen plate of the printing member is provided with a pushing structure and a return pushing structure above the middle part of the printing screen plate, the pushing structure comprises a sliding frame, and the two side walls of the sliding frame are provided with sliding grooves inclined downward, and a sliding rod is fixed in the sliding grooves along the inclined direction of the sliding rod;

[0032] A limiting sliding block is slidably arranged in the sliding groove, a rod hole is formed in the limiting sliding block, the sliding rod penetrates through the rod hole, the two side walls of the limiting sliding block are gap-fitted with the two side groove walls of the sliding groove, and the sliding hole wall in the limiting sliding block is tightly slid with the sliding rod;

[0033] A first spring is sleeved on the bottom of the sliding rod, the bottom end of the first spring is fixed on the bottom of the sliding groove, the top end of the first spring is fixed on the bottom side of the limiting sliding block, a connecting plate is connected to the middle bottom side of the limiting sliding block, a scraper is fixed to the bottom end of the connecting plate, and the scraper is located at the lowest limit value I, and the bottom side wall of the scraper is tightly contacted with the upper surface of the printing screen plate.

[0034] A through hole is formed in the middle part of the horizontal plate of the sliding frame, a telescopic rod is movably arranged in the through hole, a triangular push plate is arranged on the end circumferential surface of the telescopic rod, and the inclined surface of the push plate slides on the top side of the limiting sliding block.

[0035] As a further scheme of the present application, the printing member further comprises a connecting frame fixed on the top side of the support disc, the connecting frame is an L-shaped structure, a horizontal printing frame is fixed to the top of the connecting frame, and the printing screen plate is encapsulated in the middle part of the printing frame.

[0036] Two symmetrical supporting plates are fixed to the two sides of the top of the printing frame, a damping structure is arranged on the top side of the supporting plate, a push cylinder is fixed to the top of the other side of the printing frame, the push cylinder is vertically arranged with the two supporting plates, a telescopic rod is arranged on one side of the push cylinder, and the telescopic rod is connected to the output end of the push cylinder.

[0037] As a further scheme of the present application: further comprising a damping structure, the damping structure comprises a sliding rail, the sliding rail is fixed on the top side of the support plate, the sliding rail is a hollow structure, a magnetic metal strip is fixed in the hollow cavity of the sliding rail, a sliding block is slidably installed above the sliding rail, the two side walls of the sliding block are in sliding contact with the two side walls of the sliding rail, a sliding gasket is fixed to the top inner wall of the sliding block, and the bottom side of the sliding gasket is in sliding close contact with the top side of the sliding rail.

[0038] As a further scheme of the present application: the top of the sliding block is provided with an electromagnet, the outer side of the electromagnet is provided with a coil, and a power supply box is arranged on the sliding block to provide direct current power for the coil.

[0039] The outer side of the sliding rail is fixedly connected with the outer side of the sliding frame.

[0040] As a further scheme of the present application: a push-back structure is installed on one side of the sliding frame, the push-back structure comprises a push plate, a first mounting member is fixed to one side of the sliding frame, a second mounting member is fixed to one side of the push plate, and the first mounting member and the second mounting member are connected through a pin shaft.

[0041] A fixed plate is fixedly connected between the two inner walls of the middle part of one side of the sliding frame, a first mounting ear is fixed on the fixed plate, and a first swing cap is rotatably installed in the first mounting ear through a pin shaft.

[0042] A second connecting ear is fixed to the middle part of one side of the push plate, a second swing cap is rotatably installed in the second connecting ear, and a second spring is fixedly connected between the first swing cap and the second swing cap.

[0043] One end of the telescopic rod is fixedly connected with a push rod, and the end of the push rod is in close contact with the side wall of the push plate.

[0044] The bottom side of the push plate swings to an extreme value II, and the bottom side of the push plate is in close contact with the middle part of the side edge of the scraper.

[0045] As a further scheme of the present application: a motor is installed at the center position of the bottom of the support disc, the output shaft of the motor penetrates the bottom of the support disc, and the output shaft of the motor is fixedly connected with the drive shaft; a mark groove is arranged on the top side of the wheel changing disc corresponding to the middle part of the receiving groove, an identification camera is fixed to the middle part of the printing frame on the printing member, and the mark groove is an identification point of the identification camera.

[0046] A controller is arranged outside the support disc, the controller is used for receiving an identification signal of the identification camera for the mark groove, and the controller controls the operation of other electrical elements.

[0047] A kind of Topcon battery based on double-layer printing process, including Topcon battery body and Topcon battery double-layer printing layer, the Topcon battery double-layer printing layer is completed by printing equipment in the preparation process of a kind of Topcon battery based on double-layer printing process.

[0048] The beneficial effects of the present application are:

[0049] In the preparation process of Topcon battery is improved, the ohmic contact formed by the burn-through type silver paste dot printing can reduce the contact resistance, reduce the loss in the process of electric energy transmission, improve the fill factor and output power of the battery, by non-burn-through type low-temperature base metal paste printing, the interaction between copper and silicon is inhibited by special treatment and formula design, the contact loss is reduced by reducing its density, by the combination of two different characteristics of paste and printing method, the purpose of reducing contact loss is achieved.

[0050] In the process of screen printing, the push structure is used, which can ensure that the squeegee contacts the printing screen plate at a certain angle and realizes stable pushing of metal paste under the action of pushing force, ensures the precision and quality of printing, makes the pattern of metal electrode more accurate and uniform, and helps to improve the performance consistency of the battery.

[0051] At the same time, the back squeegee in the back push structure can effectively block and push the metal paste during printing, reduce the adhesion of the paste on the squeegee, avoid waste of paste, and at the same time, the paste on the printing screen plate is covered again during the return, which is conducive to the smooth progress of subsequent printing operation and improves the utilization rate and printing efficiency of metal paste. BRIEF DESCRIPTION OF DRAWINGS

[0052] The present application will be further described below with reference to the accompanying drawings.

[0053] Figure 1 is a schematic diagram of the printing structure in the present application;

[0054] Figure 2 is a schematic diagram of the printing structure in the present application;

[0055] Figure 3 is Figure 2 schematic diagram of the cross-sectional structure;

[0056] Figure 4 is a schematic diagram of the printing member in the present application from the first perspective;

[0057] Figure 5 is a schematic diagram of the printing member in the present application from the second perspective;

[0058] Figure 6 is a schematic diagram of the push structure in the present application;

[0059] Figure 7 is a back-pushing structure schematic diagram in the application;

[0060] Figure 8 is a damping structure diagram in the application;

[0061] Figure 9 is Figure 3 is a B area structure diagram in the application;

[0062] Figure 10 is a preparation process flow diagram of the application;

[0063] In the figure: 1, support disc, 2, rotation disc, 3, dispensing groove, 4, marking groove, 5, drive shaft, 6, identification camera, 7, printing component, 8, pushing structure, 9, back-pushing structure, 10, damping structure, 11, connecting frame, 71, printing frame, 72, printing screen, 73, connecting frame, 74, pushing cylinder, 75, telescopic rod, 76, support plate, 81, scraper, 82, first spring, 83, limiting sliding block, 84, sliding rod, 85, connecting plate, 86, push plate, 87, sliding frame, 91, push rod, 92, first swing cap, 93, first mounting ear, 94, second connecting ear, 95, second swing cap, 96, second spring, 97, fixed plate, 98, first mounting piece, 99, second mounting piece, 910, push plate, 101, slide rail, 102, sliding gasket, 103, sliding block, 104, magnetic metal strip, 105, power supply box, 106, electromagnet, 107, coil. DETAILED DESCRIPTION

[0064] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0065] Please refer to Figure 10 The preparation process of the Topcon battery based on the double-layer printing process shown in the figure includes the following steps:

[0066] S1: cleaning;

[0067] Alkaline cleaning: using a sodium hydroxide alkaline solution to remove organic impurities and grease on the surface of the silicon wafer, through chemical reaction, the organic matter is decomposed and separated from the surface of the silicon wafer, and at the same time, part of the metal impurities can also be removed;

[0068] Deionized water rinsing: the silicon wafer after alkaline cleaning is rinsed with deionized water to remove the residual alkaline solution and reaction products on the surface;

[0069] S2: Texturing;

[0070] Alkaline texturing: Using an alkaline solution such as sodium hydroxide or potassium hydroxide, adding an appropriate amount of additives such as surfactants, etc. to control the formation of the textured surface structure, the solution concentration is generally between 0.5%-5%, the type and amount of additives are adjusted according to the material of the silicon wafer and the required textured surface morphology. After texturing, rinse the silicon wafer with deionized water to remove residual alkaline solution and reaction products on the surface, and then dry to ensure the silicon wafer surface is dry and free of water stains;

[0071] S3: Tunnel oxide layer preparation;

[0072] Dry oxygen oxidation: Place the silicon wafer in a high-temperature oxidation furnace and oxidize in a dry oxygen atmosphere;

[0073] S4: Polysilicon layer deposition;

[0074] Low-pressure chemical vapor deposition, using silane as the main source gas, thermal decomposition reaction under low temperature and low pressure to form a polysilicon thin film.

[0075] S5: Diffusion and activation;

[0076] Phosphorus implantation: Use an ion implanter for phosphorus implantation. Select appropriate implantation energy and dose to ensure that phosphorus ions can penetrate the polysilicon layer and enter the silicon wafer substrate to form a P / N+ type polysilicon layer;

[0077] Activation annealing: After implantation, activation annealing is required to diffuse the implanted phosphorus ions in the silicon wafer and form effective electrically active dopants. Activation annealing is usually performed in a tube furnace or rapid thermal annealing equipment;

[0078] S6: High-temperature diffusion;

[0079] Common phosphorus diffusion sources include phosphoric acid or phosphorus oxychloride. Place the diffusion source in a quartz boat or graphite boat and place it in the diffusion furnace with the silicon wafer for diffusion;

[0080] S7: Screen printing process;

[0081] First printing is a burn-through type silver paste dot printing: Select a burn-through type silver paste as the printing material and print through the printing structure. The burn-through type silver paste has high conductivity and good burn-through ability, which can penetrate the polysilicon layer and tunnel oxide layer during high-temperature sintering, and form a good ohmic contact with the silicon wafer substrate.

[0082] The secondary printing is a non-burn-through low-temperature base metal paste printing: the secondary printing is a non-burn-through low-temperature base metal paste, and the metal paste is a copper paste, the copper paste has good conductivity, the copper paste is specially treated and formulated, and appropriate additives and passivation layers are added to inhibit the interaction between copper and silicon.

[0083] S8: sintering and light injection treatment;

[0084] The sintering treatment can form a low-resistance ohmic contact between the metal paste and the silicon wafer, and the accurate setting of the sintering temperature and time is crucial to ensure good contact between the metal and the silicon and to prevent damage to the battery structure and performance caused by high temperature. The final light injection treatment can further improve the performance and stability of the battery, optimize the transmission and collection efficiency of the carriers, and is the last link to improve the overall performance of the battery.

[0085] In the S1, the concentration of the sodium hydroxide solution is 1%-10%, the temperature is 60-80℃, and the time is 5-15min; in the S2, the texturing temperature is 70-90℃; in the S3, the oxidation temperature is generally 800-1200℃; in the S5, the injection energy is generally 10-100keV, the dose is 1*10 14 -1*10 15 cm -2 , and the annealing temperature is 800-1000℃; in the S6, the diffusion temperature is 800-1000℃; in the S8, the peak temperature of the sintering furnace is 800-950℃.

[0086] In the S4, the low-temperature environment is 500-700℃, and the low-pressure environment is 10-500pa, and the reaction equation is: SiH4→Si+2H2.

[0087] In another embodiment, a printing device based on a double-layer printing process is provided, please refer to Figures 1-3 As shown, it comprises a support disc 1, a circular groove is opened on the top side of the support disc 1, a rotating disc 2 is rotatably installed in the circular groove, a ring-shaped array of receiving grooves 3 is opened on the top side of the rotating disc 2, a printing member 7 is assembled on the side of the support disc 1, and the printing member 7 is located above the rotating disc 2; when printing the battery plate, in order to realize the assembly line operation, the motor drives the driving shaft 5 to rotate, which drives the rotating disc 2, stops every 90°, and leaves the printing time, and continues to rotate after printing is completed, and in the printing process, the corresponding feeding and discharging of the battery plate are realized by the cooperation of the mechanical arms on both sides, so as to realize the assembly line printing operation.

[0088] Please refer to Figures 4-6As shown, the push structure 8 is arranged on the middle of the printing screen plate 72 of the printing member 7, and the push structure 8 comprises a sliding frame 87, and the two side walls of the sliding frame 87 are provided with inclined sliding grooves, and the sliding grooves are internally fixed with sliding rods in the inclined direction of the sliding rods 84, so that the sliding block 83 can be well limited and guided during the silk screen printing, so that the scraper 81 can be contacted with the printing screen plate 72 at a certain angle, and better printing can be achieved.

[0089] The sliding block 83 is slidably arranged in the sliding groove, the sliding block 83 is internally provided with a rod hole, the sliding rod penetrates through the rod hole, the two side walls of the sliding block 83 are gap-fitted with the two side groove walls of the sliding groove, and the sliding hole wall in the sliding block 83 is tightly slid with the sliding rod 84.

[0090] The bottom of the sliding rod 84 is sleeved with the first spring 82, the bottom end of the first spring 82 is fixed on the bottom of the sliding groove, the top end of the first spring 82 is fixed on the bottom side of the sliding block 83, the middle bottom side of the sliding block 83 is connected with the connecting plate 85, the bottom end of the connecting plate 85 is fixed with the scraper 81, the scraper 81 is located at the lowest limit value, and the bottom side wall of the scraper 81 is tightly contacted with the upper surface of the printing screen plate 72.

[0091] Please refer to Figure 9 As shown, the through hole is internally movably provided with the telescopic rod 75, the end circumferential surface of the telescopic rod 75 is provided with the triangular push plate 86, the inclined surface of the push plate 86 is slidably arranged on the top side of the sliding block 83, the sliding block 83 can be extruded when the push plate 86 and the sliding block 83 relatively slide, so as to downward push the scraper 81 and print the battery piece moving to the bottom side of the printing screen plate 72.

[0092] The sliding groove and the sliding rod 84 can accurately limit the up-down sliding of the sliding block 83, so as to ensure the contact angle of the scraper 81 and the printing screen plate 72.

[0093] The push structure 8 can be pushed to move under the extension of the push cylinder 74 and the resistance of the damping structure 10.

[0094] The movement process of the telescopic rod 75 is divided into two stages. In the first stage, the bottom push plate 86 is driven to move in the extension process of the telescopic rod 75, and the sliding frame 87 does not move under the resistance of the damping structure 10. With the pushing of the push plate 86, the inclined surface of the push plate 86 acts on the bottom of the limiting sliding block 83, and with the pushing of the push plate 86, the limiting sliding block 83 is subjected to a downward inclined force, so that the limiting sliding block 83 slides along the sliding rod 84, and the first spring 82 is compressed, and the first spring 82 generates a restoring force. With the downward sliding of the limiting sliding block 83, the connecting plate 85 cooperates to make the scraper 81 move downward at a fixed angle to the contact state with the printing screen plate 72;

[0095] In the second stage, when the scraper 81 pushes the metal paste on the printing screen plate 72 at a fixed angle, the pushing force provided by the push cylinder 74 overcomes the resistance of the damping structure 10, and the sliding frame 87 can be pushed to move. The scraper 81 slides relative to the printing screen plate 72 in the form of contacting the printing screen plate 72, and the metal paste can be pushed by the scraper 81 to realize the printing of the solar cell piece;

[0096] Please refer to Figures 4-5 As shown in the figure, the printing member 7 further comprises a connecting frame 73 fixed on the top side of the support disc 1, the connecting frame 73 is an L-shaped structure, the top of the connecting frame 73 is fixed with a printing frame 71 in a horizontal state, the middle of the printing frame 71 is packaged with a printing screen plate 72, and the printing frame 71 supported by the connecting frame 73 is located above one of the receiving grooves 3, so that the cell piece after feeding can be printed;

[0097] The top of the printing frame 71 is fixed with a support plate 76 on both sides, the top side of the support plate 76 is provided with a damping structure 10, the damping structure 10 provides a reverse resistance for the downward pushing of the scraper 81, which can ensure the contact state of the scraper 81 and the printing screen plate 72, and can also push the material at a certain angle. The other side edge of the printing frame 71 is fixed with a push cylinder 74, the push cylinder 74 is vertically arranged with the two support plates 76, the push cylinder 74 is provided with a telescopic rod 75 on one side, and the output end of the push cylinder 74 is connected with the telescopic rod 75.

[0098] Please refer to Figure 5 As shown in the figure, the outer side of the sliding block 103 and the outer side of the sliding frame 87 are fixed with a connecting frame 11, which can realize the synchronous operation of the sliding block 103 and the sliding frame 87 under the cooperation of the connecting frame 11;

[0099] Please refer to Figure 8As shown, the damping structure 10 includes a slide rail 101 fixed on the top side of the support plate 76, the slide rail 101 is a hollow structure, a magnetic metal strip 104 is fixed in the hollow cavity of the slide rail 101, a sliding block 103 is slidingly installed above the slide rail 101, the two side inner walls of the sliding block 103 are in sliding contact with the two side walls of the slide rail 101, a sliding gasket 102 is fixed on the top inner wall of the sliding block 103, and the bottom side of the sliding gasket 102 is in sliding close contact with the top side of the slide rail 101.

[0100] The top of the sliding block 103 is provided with an electromagnet 106, the outer side of the electromagnet 106 is provided with a coil 107, and a power box 105 is arranged on the sliding block 103, and a rectifier is arranged in the power box 105, which can convert alternating current into direct current. When the direct current passes through the coil 107, the electromagnet 106 can generate an adsorbing magnetic force;

[0101] In use, in order to generate resistance to the pushing structure 8, during the pushing movement of printing, the coil 107 is powered by the power box 105, so that the magnetic force of the bottom of the electromagnet 106 is enhanced, the magnetic attraction metal strip 104 in the slide rail 101 can generate an adsorbing force, the sliding gasket 102 on the inner wall of the sliding block 103 can generate a pressing force on the upper surface of the slide rail 101, and the resistance of the sliding gasket 102 and the upper surface of the slide rail 101 is increased under the cooperation of the pressing force.

[0102] The resistance of the first stage movement of the telescopic rod 75 can be provided, so that the state of the sliding frame 87 does not relatively slide when the telescopic rod 75 moves in the first stage;

[0103] When the telescopic rod 75 moves in the second stage, the resistance of the damping structure 10 after being powered on can be overcome, the pushing structure 8 is pushed, so that the scraper 81 stably contacts the printing screen plate 72, and the printing of the battery piece is realized.

[0104] One side of the sliding frame 87 is provided with a back-pushing structure 9, the back-pushing structure 9 includes a back scraper 910, one side of the sliding frame 87 is fixed with a first mounting piece 98, one side of the back scraper 910 is fixed with a second mounting piece 99, and the first mounting piece 98 and the second mounting piece 99 are connected through a pin shaft.

[0105] Please refer to Figure 7 、 Figure 9 As shown, the two side inner walls of the middle part of one side of the sliding frame 87 are fixedly connected with a fixed plate 97, the fixed plate 97 is fixed with a first mounting lug 93, and the first mounting lug 93 is rotatably installed with a first swing cap 92 through a pin shaft.

[0106] The second connecting lug 94 is fixed in the middle of one side of the back scraping plate 910, the second swing cap 95 is rotatably installed in the second connecting lug 94, the first swing cap 92 and the second swing cap 95 are fixedly connected with the second spring 96;

[0107] One end of the telescopic rod 75 is fixed with the push rod 91, the end of the push rod 91 is tightly attached to the side wall of the back scraping plate 910;

[0108] In the state that the telescopic rod 75 is in the first stage of telescopic, with the extension of the telescopic rod 75, the push rod 91 at the end of the telescopic rod 75 is synchronously extended, under the extension of the push rod 91, the top of the back scraping plate 910 can be squeezed and pushed out, the top of the back scraping plate 910 is swung under the pushing force, the swing center is located on the pin shaft axis of the first mounting 98 and the second mounting 99, after the top of the back scraping plate 910 is forced, the top of the back scraping plate 910 is away from the top of the sliding frame 87, so that the bottom of the back scraping plate 910 is close to the sliding frame 87;

[0109] Because the scraping plate 81 is pushed to move downward before the back scraping plate 910 swings, the bottom side of the back scraping plate 910 swings to the extreme value two, the bottom side of the back scraping plate 910 is tightly attached to the middle of the side of the scraping plate 81;

[0110] After the back scraping plate 910 swings to contact the scraping plate 81, the telescopic rod 75 is in the second stage of movement, the push structure 8 and the back push structure 9 are pushed to slide horizontally;

[0111] During the sliding process, the bottom of the back scraping plate 910 is arranged at an angle with the scraping plate 81, the back scraping plate 910 can resist the pulp pushed by the scraping plate 81, avoid the pulp over the scraping plate 81, and reduce the adhesion of the pulp on the scraping plate 81;

[0112] During the swinging process of the back scraping plate 910, the second spring 96 is twisted and stretched under the cooperation of the two ends of the first swing cap 92 and the second swing cap 95, to generate a restoring force;

[0113] After the scraping plate 81 completes the scraping, during the return, the power box 105 temporarily stops the power supply to the coil 107, reduces the pressing force on the sliding block 103, so that the sliding block 103 slides along the slide rail 101 to reset in the normal state;

[0114] At this time, the push cylinder 74 is in the retraction operation, during the retraction process, the sliding frame 87 pushed to the end point drives the push plate 86 to retract, the limiting sliding block 83 loses the obliquely downward pressing force, and under the rebounding force of the two sides of the first spring 82, slides upward along the sliding rod 84, under the cooperation of the connecting plate 85, can drive the scraping plate 81 to rise and reset;

[0115] When the telescopic rod 75 is completely retracted in the first stage, the end of the push rod 91 slides synchronously under the contraction of the telescopic rod 75, at this time, the top of the back scraper 910 is not subjected to the pushing force, and under the contraction and reset action of the second spring 96, the top of the back scraper 910 is close to the top of the sliding frame 87, and the bottom of the back scraper 910 after swinging can cover the metal paste accumulated on the top side of the printing screen plate 72;

[0116] Because the diameter of the end cap of the push rod 91 is larger than the sliding hole diameter of the telescopic rod 75 through the sliding frame 87, when the end cap of the push rod 91 is moved to the side of the sliding frame 87, the sliding frame 87 can be pulled back to the reset position under the cooperation of the telescopic rod 75, and at the same time, the metal paste accumulated on the top side of the printing screen plate 72 can be covered by the back scraper 910 after swinging, so that the paste can be spread and covered on the printing screen plate 72 again during the return, so as to facilitate the pushing and printing work of the subsequent scraper 81. In addition, metal paste also needs to be supplemented in time during the printing process, so as to ensure the accuracy of printing.

[0117] The bottom center position of the support disc 1 is provided with a motor, the output shaft of the motor penetrates the bottom side of the support disc 1, and the output shaft of the motor is fixedly connected with the driving shaft 5. The top side of the wheel changing disc 2 is provided with a mark groove 4 at the middle position of the receiving slot 3, and the middle part of the printing frame 71 on the printing member 7 is fixedly provided with an identification camera 6. The mark groove 4 is the identification point of the identification camera 6. Through the identification effect of the identification camera 6, when the mark groove 4 of the wheel changing disc 2 is rotated to the position directly below the identification camera 6, it indicates that the printing and feeding are completed, and the printing work can be realized.

[0118] The support disc 1 is externally provided with a controller, the controller is used for receiving the identification signal of the identification camera 6 to the mark groove 4, and the controller controls the operation of other electrical elements.

[0119] A Topcon battery based on a double-layer printing process, comprising a Topcon battery body and a Topcon battery double-layer printing layer, wherein the Topcon battery double-layer printing layer is completed by a printing device in a preparation process of the Topcon battery based on the double-layer printing process.

[0120] Working principle of the printing device:

[0121] 1) The wheel changing disc 2 is driven to rotate by the motor, and stops every 90° to leave printing time. During the printing process, the two mechanical arms work together to realize the feeding and discharging of the battery piece, and complete the flow type printing work;

[0122] 2) When the mark groove 4 of the rotating disc 2 rotates to the position directly below the recognition camera 6, it indicates that the printing material loading is completed, and the printing operation can be performed. The support disc 1 receives the recognition signal of the mark groove 4 from the recognition camera 6, and controls the operation of other electrical components;

[0123] 3) Action of the printing member 7

[0124] The first stage of the movement of the pushing structure 8, under the extension of the push cylinder 74, the telescopic rod 75 drives the push plate 86 to move. Since the pushing structure 8 is limited by the resistance of the damping structure 10, the sliding frame 87 does not move. The inclined surface of the push plate 86 acts on the bottom of the limiting sliding block 83, pushing the limiting sliding block 83 to slide along the sliding rod 84, compressing the first spring 82. With the sliding of the limiting sliding block 83, the scraper 81 is driven by the connecting plate 85 to move downward at a fixed angle until it contacts the printing screen plate 72.

[0125] The second stage of the movement of the pushing structure 8, the pushing force provided by the push cylinder 74 overcomes the resistance of the damping structure 10, driving the sliding frame 87 to move. The scraper 81 contacts and slides relative to the printing screen plate 72, pushing the metal paste, and completing the printing.

[0126] 4) Cooperation of the back-pushing structure 9 and the damping structure 10

[0127] In the first stage of the telescopic movement of the telescopic rod 75, the push rod 91 extends and presses the back scraper 910 on the top, making it swing. The bottom of the back scraper 910 is close to the sliding frame 87 and tightly attached to the middle of the side of the scraper 81, resisting the paste pushed by the scraper 81, reducing the adhesion.

[0128] During the printing and pushing process, the power box 105 supplies power to the coil 107, the electromagnet 106 generates magnetic force to attract the magnetic metal strip 104 in the sliding rail 101, increasing the pressing force of the sliding block 103 on the sliding rail 101, and increasing the resistance of the sliding gasket 102 on the upper surface of the sliding rail 101, providing resistance for the first stage movement of the telescopic rod 75, ensuring the stability of the sliding frame 87. In the second stage of the telescopic movement of the telescopic rod 75, the resistance of the damping structure 10 after being electrified is overcome, the pushing structure 8 is driven to move, and the scraper 81 is ensured to stably contact the printing screen plate 72 and push the paste.

[0129] 5) After the printing is completed, the power box 105 stops electrifying the coil 107, the sliding block 103 slides along the sliding rail 101 to reset, the push cylinder 74 retracts, the sliding frame 87 drives the push plate 86 to retract when the telescopic rod 75 retracts, the limiting sliding block 83 slides up under the rebounding force of the first spring 82 after losing the pressing force, driving the scraper 81 to rise and reset. When the telescopic rod 75 retracts, the end of the push rod 91 slides, the back scraper 910 swings under the contraction and reset of the second spring 96, covers the metal paste on the top side of the printing screen plate 72, and at the same time, replenishes the metal paste on the printing screen plate 72.

[0130] The above detailed description has shown, by way of example, an embodiment of the application. It is specifically contemplated that the application is not limited to the embodiments described herein, but rather the scope of the application is defined by the claims.

Claims

1. A fabrication process for a Topcon battery based on a double-layer printing process, characterized in that, Includes the following steps: S1: Cleaning; S2: Fleece making; S3: Preparation of tunneling oxide layer; S4: Polycrystalline silicon layer deposition; S5: Diffusion and activation; S6: High-temperature diffusion; S7: Screen printing process; One-time printing is burn-through silver paste dot printing: burn-through silver paste is selected as the printing material, and printing is performed through the printing structure; The secondary printing is a non-burn-through type low-temperature base metal paste printing, and the metal paste is copper paste. S8: Sintering and photoinjection treatment.

2. The fabrication process of a topcon battery based on a double-layer printing process according to claim 1, characterized in that, In step S1, the sodium hydroxide solution concentration is 1%-10%, the temperature is 60℃-80℃, and the time is 5-15 minutes; in step S2, the texturing temperature is 70℃-90℃; in step S3, the oxidation temperature is generally 800℃-1200℃; in step S5, the injection energy is generally 10-100keV, and the dose is 1*10 14 -1*10 15 cm -2 The annealing temperature is 800℃-1000℃; in S6, the diffusion temperature is 800℃-1000℃; in S8, the peak temperature of the sintering furnace is 800℃-950℃.

3. The fabrication process of a topcon battery based on a double-layer printing process according to claim 1, characterized in that, In S4, the low temperature environment is 500℃-700℃, the low pressure environment is 10-500pa, and the reaction equation is: SiH4→Si+2H2.

4. A printing apparatus for fabricating a Topcon battery based on the double-layer printing process described in claim 1, characterized in that, Includes a support plate (1), the top side of the support plate (1) is provided with a circular groove, a rotating plate (2) is rotatably installed in the circular groove, the top side of the rotating plate (2) is provided with a storage groove (3) in a ring array, the side of the support plate (1) is equipped with a printing component (7), and the printing component (7) is located above the rotating plate (2). The printing screen (72) of the printing component (7) is provided with a pushing structure (8) and a pushing structure (9) above the middle part. The pushing structure (8) includes a sliding frame (87). The two side walls of the sliding frame (87) are provided with downward inclined grooves. The sliding rod is fixed inside the groove along the inclined direction of the sliding rod (84). A limiting slider (83) is slidably installed in the chute. The limiting slider (83) has a rod hole inside, and the sliding rod passes through the rod hole. The outer walls of the limiting slider (83) are fitted with the two side walls of the chute with a clearance. The sliding hole wall inside the limiting slider (83) slides in close contact with the sliding rod (84). The bottom of the sliding rod (84) is fitted with a first spring (82), the bottom end of the first spring (82) is fixed to the bottom of the slide groove, the top end of the first spring (82) is fixed to the bottom side of the limiting slider (83), the bottom side of the middle part of the limiting slider (83) is connected to a connecting plate (85), the bottom end of the connecting plate (85) is fixed with a scraper (81), the scraper (81) is located at the lowest limit value one, and the bottom side wall of the scraper (81) is in close contact with the upper surface of the printing screen (72); The sliding frame (87) has a through hole in the middle of the horizontal plate, and a telescopic rod (75) is movably installed in the through hole. A push plate (86) with a triangular structure is provided on the end circumferential surface of the telescopic rod (75). The inclined surface of the push plate (86) slides against the top side of the limiting slider (83).

5. The printing equipment according to claim 5, characterized in that, The printing component (7) also includes a connecting frame (73), which is fixed on the top side of the support plate (1). The connecting frame (73) has an L-shaped structure. A horizontal printing frame (71) is fixed on the top of the connecting frame (73), and a printing screen (72) is encapsulated in the middle of the printing frame (71). Support plates (76) are symmetrically fixed on the top two sides of the printing frame (71). A damping structure (10) is installed on the top side of the support plate (76). A push cylinder (74) is fixed on the top of the other side of the printing frame (71). The push cylinder (74) is perpendicular to the two support plates (76). A telescopic rod (75) is installed on one side of the push cylinder (74). The output end of the push cylinder (74) is connected to the telescopic rod (75).

6. The printing equipment according to claim 5, characterized in that, It also includes a damping structure (10), which includes a slide rail (101). The slide rail (101) is fixed to the top side of the support plate (76). The slide rail (101) has a hollow structure. A magnetic metal strip (104) is fixed inside the hollow cavity of the slide rail (101). A slider (103) is slidably installed above the slide rail (101). The inner walls on both sides of the slider (103) are slidably in contact with the inner walls on both sides of the slide rail (101). A sliding pad (102) is fixed to the top inner wall of the slider (103). The bottom side of the sliding pad (102) is slidably attached to the top side of the slide rail (101).

7. The printing equipment according to claim 6, characterized in that, An electromagnet (106) is provided on the top of the slider (103), and a coil (107) is provided on the outside of the electromagnet (106). A power supply box (105) is provided on the slider (103), and the power supply box (105) provides DC power to the coil (107). A connecting frame (11) is fixedly connected between the outer side of the slide rail (101) and the outer side of the slide frame (87).

8. The printing equipment according to claim 5, characterized in that, A push-back structure (9) is installed on one side of the sliding frame (87). The push-back structure (9) includes a push plate (910). A first mounting member (98) is fixed on one side of the sliding frame (87), and a second mounting member (99) is fixed on one side of the push plate (910). The first mounting member (98) and the second mounting member (99) are connected by a pin. A fixing plate (97) is fixed between the inner walls of the two sides of the middle part of one side of the sliding frame (87). A first mounting ear (93) is fixed on the fixing plate (97). A first swing cap (92) is rotatably installed in the first mounting ear (93) through a pin. A second connecting ear (94) is fixed in the middle of one side of the push plate (910). A second swing cap (95) is rotatably installed inside the second connecting ear (94). A second spring (96) is fixed between the first swing cap (92) and the second swing cap (95). One end of the telescopic rod (75) is fixed with a push rod (91), the end of the push rod (91) is pressed against the side wall of the push plate (910), and the diameter of the end cap of the push rod (91) is larger than the sliding hole diameter of the telescopic rod (75) through the sliding frame (87); The bottom side swing angle of the push plate (910) reaches the extreme value of two, and the bottom side of the push plate (910) is pressed against the middle of the side of the scraper (81).

9. The printing equipment according to claim 5, characterized in that, A motor is installed at the bottom center of the support plate (1), and the output shaft of the motor passes through the bottom side of the support plate (1). The output shaft of the motor is fixedly connected to the drive shaft (5). Marking slots (4) are respectively provided on the top side of the rotating plate (2) at the middle position of the storage slot (3). A recognition camera (6) is fixed in the middle of the printing frame (71) on the printing component (7). The marking slots (4) are the recognition points of the recognition camera (6). A controller is externally configured on the support plate (1). The controller is used to receive the recognition signal of the recognition camera (6) for the marking slot (4). The controller controls the operation of other electrical components.

10. A Topcon battery based on a double-layer printing process, characterized in that, It includes a Topcon battery body and a Topcon battery double-layer printed layer. The Topcon battery double-layer printed layer is completed using printing equipment in the Topcon battery manufacturing process based on double-layer printing technology.

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