Solar cell sintering furnace structure and solar cell sintering method

Abstract

The application provides a solar cell sintering furnace structure and a sintering method, and belongs to the field of solar cell manufacturing.The sintering furnace structure comprises a furnace body, a heating device arranged in the upper region and the lower region of the furnace body, a porous heat insulation layer arranged in the furnace body, a cavity arranged between the furnace body and the porous heat insulation layer, an air inlet pipe arranged in the top and the bottom of the furnace body and communicated with the cavity, and an air outlet pipe arranged in the top of the furnace body and communicated with the furnace cavity.The sintering furnace structure provided by the application has the cavity arranged between the furnace body and the porous heat insulation layer, and the cavity has the functions of buffering, uniform flow and dispersion for the compressed air entering through the air inlet pipe.The compressed air enters the cavity through the air inlet pipe, is uniformly infiltrated into the furnace cavity through the micropores of the porous heat insulation layer after the buffering, uniform flow and dispersion, and greatly reduces the disturbance of the compressed air directly entering the furnace cavity to the temperature and airflow in the furnace cavity, so that the stability of the sintering temperature in the furnace cavity is ensured, the secondary pollution to the sintered battery is reduced, and the battery efficiency and the qualified rate are improved.

Description

Technical Field

[0001] This invention belongs to the field of solar cell manufacturing technology, specifically relating to a solar cell sintering furnace structure and a solar cell sintering method. Background Technology

[0002] Solar cells primarily rely on a built-in electric field generated by the PN junction to separate electron-hole pairs. The substrate is doped silicon, on which silver paste is printed. During solar cell fabrication, after the silver paste is printed on the surface, high-temperature sintering is performed to form electrodes on the cell surface to collect charges. When semiconductor silicon and metallic silver come into contact, a potential barrier layer is formed due to the difference in work function, hindering charge movement and resulting in high resistance, affecting cell efficiency. Only when the semiconductor doping concentration is very high can electrons tunnel through the barrier, thus forming a low-resistance ohmic contact. However, high semiconductor doping concentrations, due to the addition of impurities, easily form a dead layer on the cell surface, causing significant recombination and affecting cell efficiency.

[0003] Adding metals such as tellurium and chromium to the slurry results in high doping at the grid lines during sintering, promoting good ohmic contact and reducing contact resistance. This requires stable cell surface temperature during sintering. The doped metals must penetrate the silicon to form a good ohmic contact, but not be so deeply doped that they penetrate the PN junction and cause leakage. Therefore, stable sintering temperature significantly impacts cell efficiency.

[0004] In the solar cell manufacturing process, sintering is a crucial step that plays a key role in the efficiency of solar cells. Current technology involves directly introducing compressed air into the sintering furnace, resulting in uneven airflow distribution and significant disturbances to internal temperature and airflow. This can potentially cause secondary contamination of the sintered cells, leading to decreased cell efficiency and yield. Summary of the Invention

[0005] This invention provides a solar cell sintering furnace structure and a solar cell sintering method, aiming to solve the problem of uneven airflow in the sintering furnace, which causes large disturbances in the temperature and airflow inside the furnace cavity, resulting in low cell efficiency and yield.

[0006] In a first aspect, to achieve the above objectives, the technical solution adopted by the present invention is: to provide a solar cell sintering furnace structure, comprising: a furnace body, wherein heating devices are respectively provided in the upper and lower regions of the furnace body, a porous heat insulation layer is provided in the furnace body, a cavity is provided between the porous heat insulation layer and the furnace body, an air inlet pipe communicating with the cavity is provided at the top and bottom of the furnace body, and an exhaust pipe communicating with the furnace cavity is also provided at the top of the furnace body through the porous heat insulation layer.

[0007] In conjunction with the first aspect, in one possible implementation, the porous insulation layer is a nanoporous insulation plate layer, wherein a lower cavity is provided between the bottom of the furnace body and the bottom insulation layer above it, and an upper cavity is provided between the top of the furnace body and the top insulation layer below it; the air inlet pipe at the bottom is connected to the lower cavity, and the air inlet pipe at the top is connected to the upper cavity.

[0008] In conjunction with the first aspect, in one possible implementation, the furnace body is divided into six sintering temperature zones, from left to right: a first sintering temperature zone, a second sintering temperature zone, a third sintering temperature zone, a fourth sintering temperature zone, a fifth sintering temperature zone, and a sixth sintering temperature zone. The first sintering temperature zone and the second sintering temperature zone share a set of air inlet pipe and exhaust pipe, and the third sintering temperature zone to the sixth sintering temperature zone share a set of air inlet pipe and exhaust pipe. A partition plate is provided between the cavities of the second sintering temperature zone and the third sintering temperature zone.

[0009] In conjunction with the first aspect, in one possible implementation, the first sintering temperature zone and the second sintering temperature zone have the same length, the third sintering temperature zone to the sixth sintering temperature zone have the same length, and the length of the first sintering temperature zone is greater than the length of the third sintering temperature zone.

[0010] In conjunction with the first aspect, in one possible implementation, the exhaust pipe is provided with a venturi tube.

[0011] In conjunction with the first aspect, in one possible implementation, the heating device includes heating lamps disposed in the upper and lower regions of the furnace body; the heating lamps are evenly distributed at intervals within the furnace body.

[0012] Secondly, embodiments of the present invention also provide a sintering method for solar cells, the method comprising:

[0013] Compressed air is introduced into the cavity through the air inlet pipe. The compressed air is evenly distributed in the cavity and then evenly penetrates into the furnace cavity through the porous insulation layer.

[0014] Adjust the heating device to increase the temperature of the multiple sintering temperature zones arranged from left to right in the furnace.

[0015] Among them, the temperature of the sintering temperature zone at the far right is higher than 800℃, while the sintering temperature of the sintering temperature zone at the far left is controlled between 400℃ and 500℃.

[0016] The conveyor belt speed inside the furnace is 200-250 inches / min.

[0017] In conjunction with the second aspect, in one possible implementation, the flow rate Q1 of compressed air entering the upper cavity through the top intake pipe is less than the flow rate Q2 of compressed air entering the lower cavity through the bottom intake pipe.

[0018] In conjunction with the second aspect, in one possible implementation, Q1 = (4 / 1 ~ 4 / 3)Q2.

[0019] In conjunction with the second aspect, in one possible implementation, the intake volume of the venturi tube installed inside the exhaust pipe is 1 / 5 to 1 / 20 of the total intake volume.

[0020] Compared with existing technologies, the solar cell sintering furnace structure and sintering method provided by this invention have the following advantages: A cavity is set between the furnace body and the porous insulation layer. The cavity buffers, equalizes, and disperses the compressed air entering through the air inlet pipe. The compressed air enters the cavity, which has a volume much larger than the cross-sectional diameter of the air inlet pipe, and its pressure is much lower than the gas pressure inside the air inlet pipe. It is also evenly dispersed and then evenly infiltrates into the furnace cavity through the micropores of the porous insulation layer. This greatly reduces the disturbance to the temperature and airflow inside the furnace cavity caused by the direct introduction of compressed air into the furnace cavity, thereby ensuring the stability of the sintering temperature inside the furnace cavity. At the same time, by setting the upper and lower air inlet flow rates and the exhaust flow rates, the waste gas generated by the slurry during the sintering process is quickly discharged from the upper part of the furnace cavity, reducing secondary pollution to the sintered cells and improving the efficiency and yield of the cells. Attached Figure Description

[0021] Figure 1 A schematic diagram of the solar cell sintering furnace structure provided in an embodiment of the present invention. Figure 1 ;

[0022] Figure 2 A schematic diagram of the solar cell sintering furnace structure provided in an embodiment of the present invention. Figure 2 ;

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. First air inlet pipe; 2. Furnace belt; 3. Battery; 4. First exhaust pipe; 5. Porous insulation layer; 6. Heating lamp tube; 7. Venturi tube; 8. Furnace body; 9. Second air inlet pipe; 10. Lower cavity; 11. Upper cavity; 12. First sintering temperature zone; 13. Second sintering temperature zone; 14. Partition plate; 15. Third sintering temperature zone; 16. Third air inlet pipe; 17. Second exhaust pipe; 18. Fourth sintering temperature zone; 19. Fifth sintering temperature zone; 20. Sixth sintering temperature zone; 21. Fourth air inlet pipe. Detailed Implementation

[0025] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0026] Please refer to the following: Figure 1 and Figure 2 The structure of the solar cell sintering furnace provided by the present invention will now be described. The solar cell sintering furnace structure includes: a furnace body 8, heating devices are respectively provided in the upper and lower regions of the furnace body 8, a porous heat insulation layer 5 is provided inside the furnace body 8, a cavity is provided between the porous heat insulation layer 5 and the furnace body 8, an air inlet pipe communicating with the cavity is provided at the top and bottom of the furnace body 8, and an exhaust pipe communicating with the furnace cavity is also provided at the top of the furnace body 8 through the porous heat insulation layer 5.

[0027] The solar cell sintering furnace structure provided by this invention has a cavity between the furnace body 8 and the porous insulation layer 5. The cavity buffers, equalizes, and disperses the compressed air entering through the air inlet pipe. The compressed air enters the cavity, which has a volume much larger than the cross-sectional diameter of the air inlet pipe, and the pressure is much lower than the gas pressure inside the air inlet pipe. It is also evenly dispersed and then evenly infiltrates into the furnace cavity through the micropores of the porous insulation layer 5. This greatly reduces the disturbance to the temperature and airflow inside the furnace cavity caused by the direct introduction of compressed air into the furnace cavity, thereby ensuring the stability of the sintering temperature inside the furnace cavity, reducing secondary pollution to the sintered cells 3, and improving the efficiency and yield of the cells 3.

[0028] In some embodiments, such as Figure 1 and Figure 2 As shown, the porous insulation layer 5 is a nanoporous insulation board layer. A lower cavity 10 is provided between the bottom of the furnace body 8 and the bottom insulation layer above it, and an upper cavity 11 is provided between the top of the furnace body 8 and the top insulation layer below it. The air inlet pipe at the bottom is connected to the lower cavity 10, and the air inlet pipe at the top is connected to the upper cavity 11.

[0029] Specifically, the sintering zone of the sintering furnace is divided into upper and lower parts. The outer shell of the furnace body 8 is made of stainless steel, which serves as support and sealing. The interior of the furnace body 8 is made of nanoporous heat insulation material, which serves as heat insulation and heat preservation. Heat insulation layers are provided on all four sides of the furnace body 8. Conventional heat insulation layers can be provided on the left and right side walls of the furnace body 8, and cavities are not required. Cavities are provided between the top and bottom of the furnace body 8 and the porous heat insulation layer 5. After compressed air is introduced, it serves as a buffer and uniform flow. The heat insulation layer is made of nanoporous heat insulation material. Compressed air permeates into the furnace cavity through the micropores, and the pressure is further reduced, which greatly reduces the impact and disturbance of compressed air on the smoke and dust and sintering temperature inside the furnace cavity, reduces secondary pollution of the furnace belt 2 and the battery 3, and improves the efficiency and yield of the battery 3.

[0030] Among them, the heat insulation material of furnace body 8 can also be some heat insulation porous materials such as aluminum silicate and calcium silicate.

[0031] In some embodiments, such as Figure 2As shown, the furnace body 8 is divided into six sintering temperature zones, from left to right: the first sintering temperature zone 12, the second sintering temperature zone 13, the third sintering temperature zone 15, the fourth sintering temperature zone 18, the fifth sintering temperature zone 19, and the sixth sintering temperature zone 20. The first sintering temperature zone 12 and the second sintering temperature zone 13 share a set of air inlet pipe and exhaust pipe, and the third sintering temperature zone 15 to the sixth sintering temperature zone 20 share a set of air inlet pipe and exhaust pipe. A partition plate 14 is provided between the cavities of the second sintering temperature zone 13 and the third sintering temperature zone 15.

[0032] This embodiment is divided into six sintering temperature zones, with the temperature of each zone increasing sequentially from left to right. That is, the furnace belt 2 gradually heats up from left to right, starting with preheating, until reaching the highest sintering temperature in the sixth sintering temperature zone 20, thus achieving high-temperature sintering of the battery 3. Since the flue gas or gases and sintering temperatures vary in different sintering temperature zones, the first sintering temperature zone 12 and the second sintering temperature zone 13 have similar temperatures and use a single set of inlet and outlet pipes. The other sintering temperature zones use a single set of inlet and outlet pipes. This allows for the introduction of different flow rates of compressed air to different sintering temperature zones to achieve optimal results.

[0033] Specifically, the first sintering temperature zone 12 and the second sintering temperature zone 13 are provided with a first exhaust pipe 4, a first air inlet pipe 1 and a second air inlet pipe 9, and the other sintering temperature zones are provided with a second exhaust pipe 17, a third air inlet pipe 16 and a fourth air inlet pipe 21.

[0034] In some embodiments, such as Figure 2As shown, the first sintering temperature zone 12 and the second sintering temperature zone 13 have the same length, and the lengths of the third sintering temperature zone 15 to the sixth sintering temperature zone 20 are the same, with the length of the first sintering temperature zone 12 being greater than the length of the third sintering temperature zone 15. By controlling the length of each sintering temperature zone, the sintering time of the battery 3 in different sintering temperature zones can be adjusted, thereby better removing organic matter from the battery 3 slurry and improving the efficiency of the battery 3. The first sintering temperature zone 12 is relatively long when the battery 3 first enters the sintering furnace, with a long sintering time and a low temperature, which can fully preheat the battery 3. After preheating in the first sintering temperature zone 12, the sintering temperature increases after entering the second sintering temperature zone 13, which can fully sinter and remove most of the organic waste gas. This, combined with the large air intake and large exhaust in the first sintering temperature zone 12 and the second sintering temperature zone 13, further enhances the sintering efficiency. After the battery 3 slurry passes through the first sintering temperature zone 12 and the second sintering temperature zone 13, most of the waste gas can be discharged. Therefore, the compressed air entering the first two sintering temperature zones and the amount of waste gas discharged are also large. After passing through the first two sintering temperature zones, most of the impurities doped in the battery 3 can be sintered to form smoke and dust, which are discharged from the exhaust pipe. When the battery 3 enters the next four sintering temperature zones, the temperature gradually increases, and after passing through three sintering temperature zones, the remaining small amount of impurities are removed. After entering the sixth sintering temperature zone 20, a clean environment can be formed. After high temperature sintering for a certain period of time, electrodes can be formed on the surface of the battery 3.

[0035] This embodiment uses six sintering temperature zones as an example. In other embodiments, multiple sintering temperature zones can be selected according to the design, such as four, five, or more, and are not limited to the number listed in this embodiment. Simultaneously, the intake and exhaust system, consisting of the intake pipe and exhaust pipe, can also be arranged according to design requirements to achieve the best sintering effect.

[0036] In some embodiments, such as Figure 1 As shown, a Venturi tube 7 is installed inside the exhaust pipe. The Venturi tube 7 is short for Venturi tube. The principle of the Venturi effect is that when wind blows over an obstruction, the air pressure near the upper port on the leeward side of the obstruction is relatively low, thus creating an adsorption effect and causing airflow. Since the exhaust is driven by the Venturi tube 7, as long as the intake pressure and flow rate of the Venturi tube 7 are kept stable, the exhaust airflow can be kept stable. By setting the intake volume of the Venturi tube 7 in the sintering section, controlling the intake volume of the Venturi tube 7 to 1 / 5 to 1 / 20 of the total intake volume, the airflow inside the furnace cavity can be kept stable, forming a uniform and stable exhaust, avoiding disturbance to the airflow and temperature inside the furnace cavity, and ensuring the stability of the ambient temperature inside the furnace cavity.

[0037] In some embodiments, such as Figure 1As shown, the heating device includes heating lamps 6 disposed in the upper and lower regions of the furnace body 8; the heating lamps 6 are evenly distributed within the furnace body 8. It should be noted that, since the lengths of each sintering temperature zone are different, the number of heating lamps 6 distributed in sintering temperature zones of different lengths varies accordingly.

[0038] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0039] Based on the same inventive concept, this application also provides a sintering method for a solar cell 3, the method comprising:

[0040] Compressed air is introduced into the cavity through the air inlet pipe. The compressed air is evenly distributed in the cavity and evenly seeps into the furnace cavity through the porous insulation layer 5.

[0041] Adjust the heating device so that the temperature of the multiple sintering temperature zones arranged from left to right inside the furnace body 8 increases sequentially.

[0042] Among them, the temperature of the rightmost sintering temperature zone is higher than 800℃, and the sintering temperature of the leftmost sintering temperature zone is controlled between 400℃ and 500℃; it should be noted that the rightmost sintering temperature zone is also the sixth sintering temperature zone 20, and the leftmost sintering temperature zone is also the first sintering temperature zone 12.

[0043] The conveying speed of the furnace belt 2 inside the furnace body 8 is 200-250 inch / min, and the conveying speed of the furnace belt 2 can be set to 220 inch / min. The sintering temperature is 850℃, which can be used for sintering of the battery 3.

[0044] Among them, the gas flow inside the furnace cavity is as follows Figure 1 As indicated by the middle arrow.

[0045] like Figure 2 As shown, this embodiment provides six sintering temperature zones, each equipped with a set of temperature sensors for temperature control. The length and sintering temperature settings of each sintering temperature zone are shown in Table 1 below. To simplify the table, temperature zones 1, 2, 3, 4, 5, and 6 correspond to the first sintering temperature zone 12, the second sintering temperature zone 13, the third sintering temperature zone 15, the fourth sintering temperature zone 18, the fifth sintering temperature zone 19, and the sixth sintering temperature zone 20, respectively.

[0046] Table 1

[0047] Temperature Zone 1 Temperature Zone 2 Temperature Zone 3 Temperature Zone 4 Temperature Zone 5 Temperature Zone 6 Length (inch) 30 30 10 10 10 10 Sintering temperature (°C) 450 500 550 620 780 850

[0048] As one embodiment of the sintering method for solar cells provided in this application, the flow rate Q1 of compressed air introduced into the upper cavity through the top air inlet pipe is less than the flow rate Q2 of compressed air introduced into the lower cavity through the bottom air inlet pipe.

[0049] Specifically, the compressed air flow rates in the upper and lower cavities can be controlled separately using a float flow meter or a proton flow meter. This ensures that the air flow rate in the lower intake pipe is controlled within 1 / 4 to 3 / 4 of the air flow rate in the upper intake pipe, creating a pattern where the lower airflow is larger than the upper airflow. This allows the gas carrying organic dust to flow evenly and parallel to the upper exhaust pipe in the furnace belt and above the battery, preventing contamination of the furnace belt and battery and improving battery efficiency.

[0050] The intake and exhaust flow settings are shown in Table 2. See Table 2 for the names. Figure 2 As shown:

[0051] First air intake pipe Second air intake pipe Third air intake pipe Fourth intake pipe First exhaust pipe Second exhaust pipe Traffic (scfm) 100 200 50 100 50 20

[0052] Figure 2 In the first sintering temperature zone 12 and the second sintering temperature zone 13, a first exhaust pipe 4, a first air inlet pipe 1 and a second air inlet pipe 9 are provided, and the other sintering temperature zones are provided with a second exhaust pipe 17, a third air inlet pipe 16 and a fourth air inlet pipe 21.

[0053] As shown in the table above, not only are the lengths and sintering times of the first and second sintering zones longer than those of the following four sintering zones, but the air intake and exhaust volumes of the first and second sintering zones are also higher. Waste impurities in the battery slurry generate a large amount of waste gas after sintering in the first two sintering zones. Therefore, the amount of compressed air introduced and the amount of waste gas discharged are also large. After passing through the first two sintering zones, most of the impurities mixed with the battery can be sintered into smoke and dust, which is then discharged from the exhaust pipe. As the battery enters the following four sintering zones, the temperature gradually increases, and the remaining small amount of impurities is removed through three sintering zones. After entering the sixth sintering zone, a clean environment is formed. After high-temperature sintering for a certain period, electrodes can be formed on the battery surface.

[0054] The sintering method designed in this embodiment can reduce disturbances inside the furnace, reduce temperature and airflow fluctuations, avoid battery contamination, and improve battery efficiency.

[0055] As one embodiment of the sintering method for solar cells provided in this application, Q1 = (4 / 1 to 4 / 3)Q2.

[0056] As one embodiment of the solar cell sintering method provided in this application, the air intake volume of the venturi tube installed in the exhaust pipe is 1 / 5 to 1 / 20 of the total air intake volume.

[0057] The fabrication process of TOPcon solar cells is as follows: The process involves texturing → boron diffusion → back-side polishing → LPCVD → phosphorus diffusion → plasma etching → decoupling → alumina coating → PECVD front and back coating → printing → sintering → testing. Before fabrication, the silicon wafers are divided into two groups, G1 and G2. Both groups use the same process before sintering. G1 is sintered using the sintering furnace and process of this invention, while G2 is sintered using a normal online sintering furnace. The parameters after testing are shown in Table 3 below.

[0058] Batch / piece Uoc Isc FF Eff G1 1000 0.686 9.981 81.40 22.13 G2 1000 0.685 9.958 81.34 22.01

[0059] The comparison of the tables shows that the short-circuit circuit of the sintering furnace and process data of this invention has a high Isc. This is because the gas infiltration has little impact on the sintering temperature, resulting in a stable temperature and preventing over-burning or under-burning. Isc and Eff are stable, and the average efficiency is 0.1 higher. In addition, the process of setting the air inlet flow rate to be smaller at the top and larger at the bottom ensures that the waste gas generated during sintering will collect at the top of the sintered battery and be discharged outside the furnace through the exhaust pipe, without polluting the battery. Therefore, the sintered battery has higher Uoc and Isc, and the Eff efficiency is also higher.

[0060] In Table 3, VOC: open-circuit voltage; Isc: short-circuit current; FF: fill factor; EFF: conversion efficiency.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of sintering a solar cell, comprising: A furnace body (8) is provided with heating devices in the upper and lower regions of the furnace body (8). The furnace body (8) is characterized by having a porous heat insulation layer (5) inside, a cavity between the porous heat insulation layer (5) and the furnace body (8), an air inlet pipe communicating with the cavity at the top and bottom of the furnace body (8), and an exhaust pipe communicating with the furnace cavity through the porous heat insulation layer (5) at the top of the furnace body (8). The method includes: Compressed air is introduced into the cavity through the air inlet pipe. The compressed air is evenly distributed in the cavity and evenly penetrates into the furnace cavity through the porous insulation layer (5). Adjust the heating device so that the temperature of the six sintering temperature zones arranged from left to right in the furnace body (8) increases sequentially. Among them, the temperature of the sintering temperature zone at the far right is higher than 800℃, while the sintering temperature of the sintering temperature zone at the far left is controlled between 400℃ and 500℃. The conveying speed of the furnace belt (2) inside the furnace body (8) is 200-250 inch / min; The flow rate Q1 of compressed air entering the upward cavity (11) through the top air inlet pipe is less than the flow rate Q2 of compressed air entering the downward cavity (10) through the bottom air inlet pipe. The porous insulation layer (5) is a nanoporous insulation plate layer. A lower cavity (10) is provided between the bottom of the furnace body (8) and the bottom insulation layer above it, and an upper cavity (11) is provided between the top of the furnace body (8) and the top insulation layer below it. The air inlet pipe at the bottom is connected to the lower cavity (10), and the air inlet pipe at the top is connected to the upper cavity (11). The furnace body (8) is divided into six sintering temperature zones, which are the first sintering temperature zone (12), the second sintering temperature zone (13), the third sintering temperature zone (15), the fourth sintering temperature zone (18), the fifth sintering temperature zone (19), and the sixth sintering temperature zone (20) from left to right. The first sintering temperature zone (12) and the second sintering temperature zone (13) share a set of air inlet pipe and exhaust pipe. The third sintering temperature zone (15) to the sixth sintering temperature zone (20) share a set of air inlet pipe and exhaust pipe. A partition plate (14) is provided between the cavity of the second sintering temperature zone (13) and the third sintering temperature zone (15). The first sintering temperature zone (12) has the same length as the second sintering temperature zone (13), the third sintering temperature zone (15) to the sixth sintering temperature zone (20) have the same length, and the length of the first sintering temperature zone (12) is greater than the length of the third sintering temperature zone (15). The air intake and exhaust volumes of the first sintering temperature zone (12) and the second sintering temperature zone (13) are higher than those of the following four sintering temperature zones. The waste impurities in the battery slurry generate a large amount of waste gas after sintering in the first two sintering temperature zones. The amount of compressed air introduced and the amount of waste gas discharged are also large. After passing through the first two sintering temperature zones, most of the impurities mixed in with the battery can be sintered into smoke and dust and discharged from the exhaust pipe. When the battery enters the following four sintering temperature zones, the temperature gradually increases, and the remaining small amount of impurities are removed by the three sintering temperature zones. After entering the sixth sintering temperature zone, a clean environment can be formed. After high temperature sintering for a certain period of time, electrodes can be formed on the surface of the battery. The flow rate of the first intake pipe (1) is 100 scfm, the flow rate of the second intake pipe (9) is 200 scfm, the flow rate of the third intake pipe is 50 scfm, and the flow rate of the fourth intake pipe is 100 scfm.

2. The sintering method of a solar cell according to claim 1, wherein The exhaust pipe is equipped with a venturi tube (7).

3. The sintering method for solar cells as described in claim 1, characterized in that, The heating device includes heating lamps (6) disposed in the upper and lower regions of the furnace body (8); the heating lamps (6) are evenly distributed at intervals within the furnace body (8).

4. The sintering method for solar cells as described in claim 1, characterized in that, The intake volume of the venturi tube (7) installed in the exhaust pipe is 1 / 5 to 1 / 20 of the total intake volume.

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