An integrated equipment for drying and curing silicon wafers for solar cells

Abstract

The present invention discloses an integrated drying and curing device for solar cell silicon wafers, comprising a loading conveyor line, a loading platform, a loading chamber, at least two linearly arranged parallel ovens, a unloading platform, an unloading conveyor line and a carrier reflow mechanism; the loading conveyor line corresponds to the feeding end of the loading platform, and the discharging end of the loading platform corresponds to the feeding end of the loading chamber; the feeding end of the unloading platform corresponds to the discharging end of the last discharging end of the box, and the discharging end of the unloading platform corresponds to the unloading conveyor line. The invention utilizes automated loading and unloading and online transportation and realizes uniform and rapid drying and curing through simultaneous heating of both sides of the silicon wafer lying flat, and can realize the reflow and reuse of the carrier; volatile organic gases can be uniformly and effectively extracted by vacuum extraction and air intake without a large amount of blowing, which effectively reduces the energy consumption of blowing; and linear loading and unloading has the advantages of high production capacity and small footprint.

Description

Technical Field

[0001] The invention relates to the technical field of solar cells, and in particular to integrated equipment for drying and curing silicon wafers of solar cells. Background Art

[0002] Photovoltaic power generation has become a technology that can replace fossil energy, which relies on the continuous reduction of production costs and the improvement of photoelectric conversion efficiency in recent years. According to the material of photovoltaic cells, solar cells can be roughly divided into two categories: one is crystalline silicon solar cells, including monocrystalline silicon solar cells and polycrystalline silicon solar cells; the other is thin-film solar cells, mainly including amorphous silicon solar cells, cadmium telluride solar cells and copper indium gallium selenide solar cells. At present, crystalline silicon solar cells with high-purity silicon as the main raw material are the mainstream products, accounting for more than 80%.

[0003] In crystalline silicon solar power generation systems, one of the most core steps to achieve photoelectric conversion is the process of processing crystalline silicon into cells that achieve photoelectric conversion. Therefore, the photoelectric conversion efficiency of cells has become a key indicator of the technical level of crystalline silicon solar power generation systems.

[0004] To improve the efficiency of the battery, establishing a passivated contact is the key. Since the photogenerated carriers move rapidly inside the silicon wafer, once they contact the surface, they will recombine and cannot be collected into current to generate electricity. If a special protective film is coated on the surface, such as silicon oxide, silicon nitride, aluminum oxide, amorphous silicon, etc., due to the saturation of the chemical bonds on the surface of the crystalline silicon and the charge field formed between the film and the crystalline silicon, they can effectively prevent the recombination of minority carriers on the surface.

[0005] In order to further improve efficiency, the new battery theory simulation requires full coverage of the passivation layer, and the carriers reach the conductive layer covering the passivation layer through the tunnel penetration effect. HIT batteries are new batteries designed based on this concept. HIT batteries cover the front and back sides of the silicon wafer with a thin layer of amorphous silicon (3-5nm), and then plate phosphorus-doped amorphous silicon and boron-doped amorphous silicon on the surface of the amorphous silicon. Because amorphous silicon has very excellent passivation properties, the conversion efficiency of HIT batteries has been greatly improved. However, amorphous silicon passivation can only withstand low-temperature processes. When it is above 250°C, the passivation effect of amorphous silicon is immediately lost. Conventional silver paste needs to be sintered at 800°C to achieve good conductivity and adhesion, which is not applicable to the silver paste used in mature printing of conventional batteries. For this reason, low-temperature silver paste has been developed specifically for HIT batteries. The low-temperature silver paste is used to transfer the paste to the surface of the silicon wafer through screen printing to form silver lines. After printing, the silver paste needs to be dried to remove the organic solvent carrier, and finally it needs to be cured. The drying and curing temperatures of low-temperature silver paste only need to be 200°C or below, and its bonding with the silicon wafer is achieved through the binder in the silver paste. Usually, low-temperature silver paste needs to be dried at 80-150°C for about 10 minutes before it can enter the next printing process after drying and curing, and the drying heating usually uses hot air or infrared heating or a combination of the two (because organic gases will evaporate during the drying process and need to be blown out).

[0006] Since silver wire printing uses screen printing technology, the production capacity of a single printer can reach 3,000 pieces per hour or even more. HIT battery production requires printing multiple times to arrange silver wires (main grid, fine grid), and each printing needs to be dried before the next printing. After the last printing, it is not only necessary to print but also to cure (curing at 200°C for 30 to 60 minutes) to achieve the best silver wire conductivity. The printing process, drying and curing process of a production line are connected together, so the printing capacity and drying and curing capacity are best matched.

[0007] In order to increase the production capacity of drying and curing, the existing technology usually uses multi-channel chain tracks to transport silicon wafers. The silicon wafers lie flat on the transmission chain, and the transmission chain passes through a set high temperature area for drying and curing. This method requires a long equipment footprint, and it will be even longer if combined with drying, curing and annealing equipment.

[0008] Other proposed improvements include: 1. Placing the silicon wafers upright between two bars, and having multiple parallel tracks moving forward in a chain-like manner through the heating zone. This greatly increases the density of silicon wafers placed per unit length. However, vertically placed silicon wafers are prone to breakage during movement between the bars, and uneven heating in the vertical direction causes uneven adhesion of the silver wire. 2. Placing silicon wafers in a basket, 50 to 100 wafers can be placed at a time. The basket is placed on a chain track passing through the heating zone, and the basket moves forward in a chain-like manner in the oven. The disadvantage is that the silicon wafers are also heated unevenly, and organic vapors between the silicon wafers in the basket are not easy to remove. Organic solvents remain between the silicon wafers, requiring a large amount of air to flow, which wastes energy. Summary of the invention

[0009] In order to solve the above technical problems, the present invention provides an integrated drying and curing device for solar cell silicon wafers, comprising a loading conveyor line, a loading platform, a loading chamber, at least two linearly parallel ovens, a unloading platform, an unloading conveyor line and a carrier reflow mechanism arranged in sequence;

[0010] The oven comprises a box body with a drying chamber, the box body has a board inlet valve corresponding to the feeding end and a board outlet valve corresponding to the discharging end; the box body also has an air inlet duct and an air outlet duct connected to the drying chamber inside; a lifting and supporting mechanism is arranged in the drying chamber; the lifting and supporting mechanism comprises a lifting drive mechanism, a lifting rod driven by the lifting drive mechanism to lift vertically, and a plurality of rows of board carriers for supporting the board arranged in parallel in the vertical direction of the lifting rod; heating plates are arranged on the upper and lower sides of each row of the board carriers;

[0011] The feeding end of the loading chamber is provided with a second plate inlet gate valve, the discharging end of the loading chamber is provided with a second plate outlet gate valve, and the second plate outlet gate valve at the discharging end of the loading chamber corresponds to the first plate inlet gate valve at the feeding end of the first oven;

[0012] The feeding conveyor line corresponds to the feeding end of the feeding platform, and the discharging end of the feeding platform corresponds to the second plate inlet gate valve of the loading chamber;

[0013] The feeding end of the unloading platform corresponds to the first board discharge gate valve at the last discharge end of the box, and the discharge end of the unloading platform corresponds to the unloading conveying line;

[0014] The silicon wafers on the loading conveyor line are grabbed by a robot and placed on the carrier of the loading platform. The carrier of the loading platform is transported to the loading chamber by a carrier conveying mechanism. The carrier in the loading chamber is transported to the first oven for drying by the carrier conveying mechanism. The carrier in the first oven is sequentially transported to the subsequent ovens for curing by the carrier conveying mechanism. The carrier in the last oven is transported to the unloading platform by the carrier conveying mechanism. The silicon wafers on the carrier of the unloading platform are transferred to the unloading conveyor line by a robot. The empty carrier on the unloading platform is refluxed to the loading platform by the provided carrier reflux mechanism for repeated loading.

[0015] The specification of the carrier is M×N; wherein M is the number of rows of silicon wafers in the moving direction of the carrier, that is, M silicon wafers in each row; N is the number of columns of silicon wafers perpendicular to the moving direction of the carrier, that is, N silicon wafers in each column; wherein, the loading conveyor line transfers the silicon wafers printed with silver paste one by one flatly and arranges them into 1 row of M wafers, and then grabs them once by a robot, moves them to the carrier of the loading platform and arranges them in a row, and so on. After placing N rows of silicon wafers, the carrier is transported by the loading platform to the loading chamber, and the loading platform receives the next empty carrier returned by the carrier reflux mechanism and starts to load silicon wafers; wherein, the dried silicon wafers filled on the carrier of the unloading platform are removed by the robot for each row of M wafers and placed on the unloading conveyor line, and the empty carrier on the unloading platform after unloading the silicon wafers is returned to the loading platform through the carrier reflux mechanism, and the carrier is repeatedly recycled in sequence.

[0016] Wherein, the lifting drive mechanism is any one of hydraulic, oil pressure and lifting motor.

[0017] The heating plate is heated by a thermal resistance wire or is provided with a plurality of heating lamps, and the longitudinal length of the heating plate is greater than the longitudinal length of the carrier plate, and the transverse length of the heating plate is greater than the transverse length of the carrier plate. In this way, the carrier plate is heated evenly from top to bottom by heating from top to bottom and the heating area is greater than the area of ​​the carrier plate.

[0018] The heating lamp is an infrared lamp, a visible light lamp or an ultraviolet lamp. The heat generated by the heating lamp heats the silicon wafer on the carrier. The heating plate can be densely placed LED light lamps or other flat light lamps or lamp tubes.

[0019] The drying and curing integrated equipment of the above structure has an oven that can simultaneously support multiple rows of carriers with silicon wafers by using multiple rows of vertically arranged carrier brackets, and by providing heating sources on both the upper and lower sides of each row of carriers, it is possible to effectively achieve uniform heating, drying or curing of the multiple rows of carriers at the same time (wherein, the first oven connected to the loading chamber is mainly used for drying silicon wafers, and its heating temperature is set to 80-150°C for drying for about 10 minutes for drying low-temperature silver paste; wherein, the subsequent oven is mainly used for curing low-temperature silver paste on silicon wafers, and the heating temperature is set at 200°C for curing for 30-60 minutes Therefore, it is usually necessary to linearly and parallelly set a plurality of ovens for curing. Usually, the carrier stays in each oven for curing for 10 minutes. If the requirement of curing for 60 minutes is to be met, 6 ovens for curing need to be linearly and parallelly set, that is, the integrated equipment needs to linearly set 7 ovens to meet the above drying and curing requirements, and the specific quantity and time are set according to the needs), and while drying or curing, the valves of the air inlet and outlet pipes are opened to achieve blowing and timely discharge the volatile organic gas on the silicon wafer out of the box, so as to quickly realize batch drying or curing of silicon wafers.

[0020] Among them, the carrier bracket is set to a lifting type, and the chain roller conveyor line can be used to send the carriers loaded with silicon wafers into the box one by one and stack them one by one through the lifting of the carrier bracket; moreover, each heating plate can be set to independently control the temperature, and the heating method can be a heating plate heated by distributed thermal resistance wires or arranged heating lamps can be used to use light heating to make the surface of the silicon wafer on the carrier evenly heated from top to bottom.

[0021] The temperature of each heating plate corresponding to the carrier can be set and controlled independently. The target temperature is generally set at 80-200°C so that the heating of each silicon wafer on the carrier can be controlled separately.

[0022] The number of substrates that can be stored in the box is the number of layers on the substrate holder. The number of layers can be designed to match the time required for drying. The more layers there are, the longer each substrate can stay in the box to achieve the predetermined production capacity. For example, if 40 silicon wafers are placed on each substrate, in order to ensure that the drying time of each silicon wafer reaches 10 minutes and at the same time meet the production capacity of 3,600 wafers / hour, the substrate holder needs to be set to 9 layers, that is, 9 substrates can be placed in the box at the same time.

[0023] Among them, the air inlet pipe and the air outlet pipe on the box body are both equipped with valves. Opening the valve of the air inlet pipe can allow air, nitrogen and other gases to enter, and opening the valve of the air outlet pipe can allow air, nitrogen and other gases mixed with volatile organic gases to be discharged, thereby achieving drying and exhausting at the same time.

[0024] Wherein, the loading chamber is also connected to the vacuum pumping equipment through a vacuum valve 1.

[0025] Wherein, the air outlet duct of the first oven is connected to the loading chamber through a second vacuum valve.

[0026] In the above structure, the loading chamber and the drying oven are connected by a chain roller conveyor line, and the carrier loaded with silicon wafers enters the loading chamber from the plate inlet gate valve 2 of the loading chamber through the chain roller conveyor line, and then the plate inlet gate valve 2, the plate outlet gate valve 2 and the vacuum valve 2 are closed, and the vacuum valve 1 is opened to evacuate the loading chamber by a vacuum pump; then the vacuum valve 2 of the air outlet pipe connecting the loading chamber and the box body is opened to allow the gas in the box body to backfill into the loading chamber so that the air pressure balance is achieved between the loading chamber and the oven, and then the plate outlet valve 2 of the loading chamber and the plate inlet valve 1 of the box body are opened to transfer the carrier to the carrier bracket in the box body; the above steps are repeated to realize the stacking loading of the carriers on the carrier bracket, and the carriers can be heated by the corresponding controlled heating plate while loading, or they can be heated together after multiple layers are loaded.

[0027] Among them, after the carrier is transferred to the loading chamber by rollers, it can be evacuated to reach the set vacuum degree (50~40000Pa); when the carrier leaves the oven, the air inlet pipe valve on the box body is opened to connect to the atmosphere and inject clean air (CDA) to atmospheric pressure. This type of oven exhaust and air intake method is conducive to the rapid discharge of evenly volatilized organic gases in the oven, which is equivalent to the organic gases in the oven being discharged to the exhaust gas treatment center through the vacuum pump connected to the loading chamber, and the oven exhaust and air intake cycle is the cycle of the carrier entering and exiting the oven. This cycle is about 30 to 60 seconds to achieve synchronous loading and exhaust and air intake and maintain a consistent rhythm; after the carrier has been dried in the oven for a certain period of time, it can be moved out of the oven layer by layer through the chain roller transmission line. After the carrier is moved out of the oven for drying, it enters the subsequent oven for curing for curing. After curing is completed, the carrier is moved out of the oven and enters the unloading table, and then enters the unloading conveyor line from the unloading table, thus completing the efficient linear loading and unloading, drying and curing of the low-temperature silver paste on the silicon wafer after screen printing.

[0028] Through the above technical solution, the present invention has the following advantages:

[0029] 1) It can realize the loading of silicon wafers onto carriers on the upper material conveyor line, the loading of carriers equipped with silicon wafers on the loading conveyor line onto the upper material platform, the feeding of carriers equipped with silicon wafers on the loading platform into the loading chamber, the multi-layered feeding of the loading chamber into the oven, the drying of low-temperature silver paste on silicon wafers in the oven for drying, the curing of low-temperature silver paste on silicon wafers in multiple linear parallel ovens for curing, the unloading of carriers in the oven to the lower material platform, the unloading of carriers on the unloading platform to the lower material conveyor line, and the reflux and reuse of carriers between the unloading platform and the loading platform, thereby realizing the automatic online loading, drying and unloading;

[0030] 2) The silicon wafer is placed flat for heating and drying, and both sides are heated simultaneously to ensure uniform heating of the silicon wafer and achieve fast and uniform drying;

[0031] 3) The volatile organic gas can be evenly and effectively extracted by vacuum extraction and air intake, so there is no need for a large amount of blowing, which effectively reduces the energy consumption of blowing;

[0032] 4) The box-type structure multi-layer loading and drying method has the advantages of high production capacity and small footprint. By optimizing the carrier structure and the number of carrier layers in the oven, it can match the production capacity of silver wire screen printing, and the production capacity can reach 3,000 pieces / hour or even more. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0034] Figure 1 This is a schematic diagram of the structure of the drying and curing integrated equipment disclosed in an embodiment of the present invention.

[0035] The numbers in the figure indicate: 10. Box body; 11. Drying chamber; 121. Board inlet valve 1; 122. Board outlet valve 1; 131. Air inlet duct; 132. Air outlet duct; 14. Lifting drive mechanism; 15. Lifting rod; 16. Board carrier bracket; 17. Heating plate; 18. Lamp tube; 20. Loading chamber; 211. Board inlet valve 2; 212. Board outlet valve 2; 22. Vacuum pump; 221. Vacuum valve 1; 222. Vacuum valve 2; 30. Board carrier; 40. Silicon wafer; 51. Loading conveyor line; 52. Unloading conveyor line; 61. Loading platform; 62. Unloading platform. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0037] refer to Figure 1 The present invention provides an integrated drying and curing device for solar cell silicon wafers, comprising a loading conveyor line 51, a loading platform 61, a loading chamber 20, at least two linearly parallel ovens, a loading platform 62, a loading conveyor line 52 and a carrier reflow mechanism, which are sequentially arranged;

[0038] The oven comprises a box body 10 having a drying chamber 11, the box body 10 having a board inlet valve 121 corresponding to the feeding end and a board outlet valve 122 corresponding to the discharging end; the box body 10 also has an air inlet duct 131 and an air outlet duct 132 communicating with the internal drying chamber; a lifting and supporting mechanism is arranged in the drying chamber; the lifting and supporting mechanism comprises a lifting drive mechanism 14, a lifting rod 15 driven to lift vertically by the lifting drive mechanism 14, and a plurality of rows of board support brackets 16 for supporting the board 30 arranged in parallel in the vertical direction of the lifting rod 15; heating plates 17 are arranged on the upper and lower sides of each row of board support brackets 16;

[0039] The feeding end of the loading chamber 20 is provided with a second board inlet valve 211, and the discharging end of the loading chamber 20 is provided with a second board outlet valve 212, and the second board outlet valve 212 at the discharging end of the loading chamber 20 corresponds to the first board inlet valve 121 at the feeding end of the first oven;

[0040] The feeding conveyor line corresponds to the feeding end of the feeding platform 61, and the discharging end of the feeding platform 61 corresponds to the plate inlet valve 211 of the loading chamber 20;

[0041] The feeding end of the unloading platform 62 corresponds to the board discharge gate valve 122 at the discharge end of the last box 10, and the discharge end of the unloading platform 62 corresponds to the unloading conveying line;

[0042] The silicon wafers on the loading conveyor line 51 are grabbed by a robot and placed on the carrier 30 of the loading platform 61. The carrier 30 of the loading platform 61 is transported to the loading chamber 20 by the carrier conveying mechanism. The carrier 30 in the loading chamber 20 is transported to the first oven for drying by the carrier conveying mechanism. The carrier 30 in the first oven is sequentially transported to the subsequent ovens for curing by the carrier conveying mechanism. The carrier 30 in the last oven is transported to the unloading platform 62 by the carrier conveying mechanism. The silicon wafers on the carrier 30 of the unloading platform 62 are transferred to the unloading conveyor line 52 by a robot. The carrier 30 above the unloading platform 62 is refluxed to the loading platform 61 by the provided carrier reflux mechanism for repeated loading.

[0043] The specification of the carrier 30 is M×N; wherein M is the number of rows of silicon wafers 40 in the moving direction of the carrier 30, that is, M silicon wafers 40 in each row; N is the number of columns of silicon wafers 40 perpendicular to the moving direction of the carrier 30, that is, N silicon wafers 40 in each column; wherein the feeding conveyor line transmits the silicon wafers 40 printed with silver paste one by one flatly and arranges them into a row of M wafers, and then grabs them at one time by the robot arm and transfers them to the carrier 30 of the feeding table 61 to be arranged in a row, and so on, after placing N columns of silicon wafers 40 0, the carrier 30 is transported to the loading chamber 20 by the loading platform 61, the loading platform 61 receives the next empty carrier 30 returned by the carrier reflow mechanism and starts to load the silicon wafers 40; wherein, the dried silicon wafers 40 loaded on the carrier 30 of the unloading platform 62 are taken off by the robot for each row of M wafers and placed on the unloading conveyor line, and the empty carrier 30 on the unloading platform 62 after unloading the silicon wafers 40 is returned to the loading platform 61 through the carrier reflow mechanism, and the carrier 30 is repeatedly recycled in sequence.

[0044] The lifting drive mechanism 14 is any one of hydraulic, oil pressure and lifting motor. The heating plate 17 is heated by a thermal resistance wire or is arranged with multiple heating lamps, and the longitudinal length of the heating plate 17 is greater than the longitudinal length of the carrier 30, and the transverse length of the heating plate 17 is greater than the transverse length of the carrier 30, so that the carrier 30 is evenly heated from top to bottom by heating up and down and the heating area is greater than the area of ​​the carrier 30. The heating lamp is an infrared lamp, a visible light lamp or an ultraviolet lamp. The heat generated by the light emitted by the heating lamp is used to heat the silicon wafer 40 on the carrier 30. The heating plate 17 can be a densely placed LED light lamp or other flat light lamps or lamp tubes 18. The loading chamber 20 is also connected to the vacuum pump 22 through the vacuum valve 1 221; the exhaust pipe 132 of the first oven is connected to the loading chamber 20 through the vacuum valve 222.

[0045] In the present embodiment 1, multiple rows of vertically arranged carrier brackets 16 can simultaneously support multiple rows of carriers 30 with silicon wafers 40, and by providing heating sources on both the upper and lower sides of each row of carriers 30, the multiple rows of carriers 30 can be effectively and evenly heated, dried or cured at the same time (wherein, the first oven connected to the loading chamber 20 is mainly used for drying the silicon wafers 40, and its heating temperature is set to 80-150° C. for drying for about 10 minutes for drying the low-temperature silver paste; wherein, the subsequent oven is mainly used for curing the low-temperature silver paste on the silicon wafer 40, and the heating temperature is set to 200° C. for curing for 30-60 minutes, therefore, Usually, multiple ovens for curing need to be arranged linearly in parallel. Usually, the carrier 30 stays in each oven for curing for 10 minutes. If the requirement of curing for 60 minutes is to be met, 6 ovens for curing need to be arranged linearly in parallel, that is, the integrated device needs to be linearly arranged with 7 ovens to meet the above-mentioned drying and curing requirements, and the specific quantity and time are set according to the needs), and while drying or curing, the valves of the air inlet pipe 131 and the air outlet pipe 132 are opened to achieve blowing and timely discharge the volatile organic gas on the silicon wafer 40 out of the box 10, so as to quickly achieve batch drying or curing of the silicon wafer 40.

[0046] Among them, the carrier bracket 16 is set to a lifting type, and the carriers 30 loaded with silicon wafers 40 can be sent to the box 10 one by one by using a chain roller conveyor line and stacked one by one through the lifting of the carrier bracket 16; moreover, each heating plate 17 can be set to independently control the temperature, and the heating method can be a heating plate 17 heated by a distributed thermal resistance wire or can use arranged heating lamps to use light heating to make the surface of the silicon wafer 40 on the carrier 30 evenly heated from top to bottom.

[0047] The temperature of each heating plate 17 corresponding to the carrier 30 can be set and controlled independently. Generally, the target temperature is set at 80-200° C. so that the heating of each silicon wafer 40 on the carrier 30 can be controlled separately.

[0048] The number of carriers 30 that can be stored in the box 10 is the number of layers on the carrier bracket 16, and its number design can be matched with the required drying time. The more layers there are, the longer the residence time of each carrier 30 in the box 10 can be in order to achieve the predetermined production capacity. For example, if 40 silicon wafers 40 are placed on each carrier 30, in order to ensure that the drying time of each silicon wafer 40 reaches 10 minutes and at the same time meet the production capacity of 3600 pieces / hour, the carrier bracket 16 needs to be set to 9 layers, that is, 9 carriers 30 can be placed in the box 10 at the same time.

[0049] Among them, the air inlet pipe 131 and the air outlet pipe 132 on the box body 10 are both provided with valves. Opening the valve of the air inlet pipe 131 can allow air, nitrogen and other gases to enter, and opening the valve of the air outlet pipe 132 can allow air, nitrogen and other gases mixed with volatile organic gases to be discharged, thereby achieving drying and exhausting at the same time.

[0050] Among them, the loading chamber 20 and the box body 10 are connected by a chain roller conveyor line, and the carrier 30 loaded with silicon wafers 40 enters from the board inlet gate valve 211 of the loading chamber 20 through the chain roller conveyor line, and then the board inlet gate valve 211, the board outlet gate valve 212 and the vacuum valve 2 are closed, and the vacuum valve 1 is opened to evacuate the loading chamber 20 through a vacuum pump; then the vacuum valve 2 of the air outlet pipe 132 connecting the loading chamber 20 and the box body 10 is opened to allow the gas in the box body 10 to backfill into the loading chamber 20 so that the air pressure balance is achieved between the loading chamber 20 and the oven, and then the board outlet valve 2 of the loading chamber 20 and the board inlet valve 1 of the box body 10 are opened, so as to transfer the carrier 30 to the carrier bracket 16 in the box body 10; repeat the above steps to realize the stacking loading of the carrier 30 on the carrier bracket 16, which can be heated by the corresponding controlled heating plate 17 while loading, or can be heated together after multiple layers are loaded.

[0051] Among them, after the carrier 30 is transferred to the loading chamber 20 by the roller, it can be evacuated to reach the set vacuum degree (50~40000Pa); when the carrier 30 leaves the oven, the valve of the air inlet duct 131 on the box body 10 is opened to connect to the atmosphere and inject clean air (CDA) to atmospheric pressure. This type of oven exhaust and air intake method is conducive to the rapid discharge of organic gases that are uniformly volatilized in the oven, which is equivalent to the organic gases in the oven being discharged to the exhaust gas treatment center through the vacuum pump connected to the loading chamber 20, and the oven exhaust and air intake cycle is the cycle of the carrier 30 entering and exiting the oven. This cycle is about 30 to 60 seconds to achieve synchronous loading and exhaust and air intake and maintain a consistent rhythm; after the carrier 30 has been dried in the oven for a certain period of time, it can be moved out of the oven layer by layer through the chain roller transmission line. After the carrier 30 is moved out of the oven for drying, it enters the subsequent oven for curing for curing. After curing is completed, the carrier 30 is moved out of the oven and enters the unloading table 62, and then enters the unloading conveyor line 52 from the unloading table 62, that is, the efficient linear loading and unloading, drying and curing of the low-temperature silver paste on the silicon wafer 40 after screen printing are completed.

[0052] Through the above technical scheme, the present invention can realize the loading of silicon wafers 40 onto the carrier 30 on the upper material conveyor line, the loading of the carrier 30 equipped with silicon wafers 40 on the loading conveyor line onto the upper material platform 61, the feeding of the carrier 30 equipped with silicon wafers 40 on the loading platform 61 into the loading chamber 20, the multi-layer arrangement feeding of the loading chamber 20 into the oven, the drying of low-temperature silver paste on the silicon wafers 40 in the oven for drying, the curing of low-temperature silver paste on the silicon wafers 40 in multiple linear parallel ovens for curing, the unloading of the carrier 30 in the oven from the lower material platform 62, the unloading of the carrier 30 on the unloading platform 62 to the lower material conveyor line 52, and the carrier 30 between the unloading platform 62 and the loading platform 61. The reflux can be reused, thereby realizing the automatic online loading, drying and unloading; the silicon wafer 40 is placed flat for heating and drying, and the double-sided heating can ensure that the silicon wafer 40 is evenly heated to achieve fast and uniform drying; the volatile organic gas can be evenly and effectively extracted by vacuum extraction and air intake, so there is no need for a large amount of blowing, which effectively reduces the energy consumption of blowing; the box-type structure multi-layer loading and drying method has the advantages of high production capacity and small footprint. By optimizing the structure of the carrier 30 and the number of carrier layers 30 in the oven, it can match the production capacity of silver wire screen printing, and the production capacity can reach 3000 pieces / hour or even more.

[0053] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to the above embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A solar cell silicon wafer drying and curing integrated device, characterized in that: It includes a loading conveyor line, a loading platform, a loading chamber, at least two linearly parallel ovens, a loading platform, a loading conveyor line and a carrier plate reflow mechanism; The oven comprises a box body with a drying chamber, the box body has a board inlet valve corresponding to the feeding end and a board outlet valve corresponding to the discharging end; the box body also has an air inlet duct and an air outlet duct connected to the drying chamber inside; a lifting and supporting mechanism is arranged in the drying chamber; the lifting and supporting mechanism comprises a lifting drive mechanism, a lifting rod driven by the lifting drive mechanism to lift vertically, and a plurality of rows of board carriers for supporting the board arranged in parallel in the vertical direction of the lifting rod; heating plates are arranged on the upper and lower sides of each row of the board carriers; The feeding end of the loading chamber is provided with a second plate inlet gate valve, the discharging end of the loading chamber is provided with a second plate outlet gate valve, and the second plate outlet gate valve at the discharging end of the loading chamber corresponds to the first plate inlet gate valve at the feeding end of the first oven; The feeding conveyor line corresponds to the feeding end of the feeding platform, and the discharging end of the feeding platform corresponds to the second plate inlet gate valve of the loading chamber; The feeding end of the unloading platform corresponds to the first board discharge gate valve at the last discharge end of the box, and the discharge end of the unloading platform corresponds to the unloading conveying line; The silicon wafers on the loading conveyor line are grabbed by a robot and placed on the carrier of the loading platform. The carrier of the loading platform is transported to the loading chamber by a carrier conveying mechanism. The carrier in the loading chamber is transported to the first oven for drying by the carrier conveying mechanism. The carrier in the first oven is sequentially transported to the subsequent ovens for curing by the carrier conveying mechanism. The carrier in the last oven is transported to the unloading platform by the carrier conveying mechanism. The silicon wafers on the carrier of the unloading platform are transferred to the unloading conveyor line by a robot. The empty carrier on the unloading platform is refluxed to the loading platform by the provided carrier reflux mechanism for repeated loading. The specification of the carrier is M×N; wherein M is the number of rows of silicon wafers in the moving direction of the carrier, that is, M silicon wafers per row; N is the number of columns of silicon wafers perpendicular to the moving direction of the carrier, that is, N silicon wafers per column; The lifting drive mechanism is any one of hydraulic, oil pressure and lifting motor; The loading chamber is also connected to a vacuum pumping device via a vacuum valve.

2. The integrated device for drying and curing silicon wafers for solar cells according to claim 1, characterized in that: The heating plate is heated by a thermal resistance wire or is provided with a plurality of heating lamps, and the longitudinal length of the heating plate is greater than the longitudinal length of the carrier plate, and the transverse length of the heating plate is greater than the transverse length of the carrier plate.

3. The integrated device for drying and curing silicon wafers for solar cells according to claim 2, characterized in that: The heating lamp tube is an infrared lamp tube, a visible light lamp tube or an ultraviolet light lamp tube.

4. The solar cell silicon wafer drying and curing integrated equipment according to claim 1, characterized in that: The gas outlet duct of the first oven is connected to the loading chamber through a second vacuum valve.

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