Silicon wafer texturing device, texturing method and application

Abstract

The present invention provides a silicon wafer texturing device, a texturing method and an application. The silicon wafer texturing device comprises a shell and a texturing tank located in the shell. A rotating assembly is arranged in the texturing tank. An ultrasonic assembly and a heating assembly are arranged below and around the texturing tank respectively. The rotating assembly comprises a main shaft located inside the texturing tank and a motor connected to the main shaft. The motor drives the main shaft and the silicon wafer arranged on the main shaft to rotate around the shaft. The silicon wafer texturing device provided by the present invention can improve the efficiency and uniformity of silicon wafer texturing.

Description

Technical Field

[0001] The invention belongs to the technical field of silicon wafer texturing, and relates to a silicon wafer texturing device, a texturing method and an application. Background Art

[0002] In the past thirty years, solar energy utilization technology has developed rapidly in research and development, commercial production, and market development, becoming one of the world's fastest and most stable emerging industries. Silicon solar cells are an effective way to utilize solar energy. Chemical texturing is a key link in the manufacture of silicon solar cells. It has an important impact on the light absorption rate of solar cells and is also one of the key factors determining the cost of solar cells per kilowatt-hour. However, there are still major deficiencies in the current silicon wafer texturing process. Common problems in silicon wafer texturing include: large amounts of chemicals used, low chemical reaction efficiency, and defects such as white spots, bright surfaces, tooth marks, and bubbles that are prone to appear on silicon wafers during the texturing process.

[0003] CN210684001U discloses a high-efficiency single crystal texturing equipment, including a feeding device, an ultrasonic cleaning tank, a water tank A, a single crystal alkali texturing tank, a water tank B, an acid texturing tank, a water tank C, an acid washing silver removal tank, a water tank D, an acid washing modification tank, a water tank E, an alkali washing tank, a water tank F, an acid washing tank, a water tank G, a slow pulling tank, and a feeding device. However, the equipment has a complex structure and cumbersome steps. Alkaline texturing and acid texturing are combined for texturing, and a large amount of chemicals are used.

[0004] CN204391146U discloses a wet texturing device, including a liquid storage tank, a texturing tank and a circulation pump, wherein at least two liquid outlet pipes are provided in the texturing tank, and one end of the liquid outlet pipe is connected to the liquid storage tank through the circulation pump; the liquid outlet pipe is provided with a plurality of drainage holes along its length, and the number of drainage holes away from one end of the circulation pump is greater than the number of drainage holes at one end adjacent to the circulation pump. However, the texturing device has the problem of low texturing efficiency.

[0005] CN111430292A provides a large-size silicon wafer texturing bearing device, comprising a side rod assembly and a bottom rod assembly, wherein: one of the side rod assembly and the bottom rod assembly is provided with a first tooth groove, and the other is provided with a second tooth groove; or both are provided with the first tooth groove; or both are provided with the second tooth groove; the first tooth groove and the second tooth groove are both provided along the length direction of the side rod assembly and the bottom rod assembly and are both provided toward the axis of the silicon wafer. However, the reaction efficiency of the texturing process cannot be improved by using the device.

[0006] At present, the silicon wafer texturing process still has problems such as low reaction efficiency and uneven texturing. Therefore, a silicon wafer texturing device is urgently needed to improve the efficiency and uniformity of silicon wafer texturing. Summary of the invention

[0007] In view of the deficiencies in the prior art, the object of the present invention is to provide a silicon wafer texturing device, a texturing method and applications, which can improve the efficiency and uniformity of silicon wafer texturing.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a silicon wafer texturing device, the silicon wafer texturing device comprising a shell and a texturing tank located in the shell, a rotating component is arranged in the texturing tank, and an ultrasonic component and a heating component are respectively arranged below and around the texturing tank;

[0010] The rotating assembly includes a main shaft located inside the texturing tank, and a motor drivingly connected to the main shaft;

[0011] The motor drives the main shaft and the silicon wafer disposed on the main shaft to rotate around the axis;

[0012] The texturing tank contains texturing liquid, and the silicon wafer is immersed in the texturing liquid.

[0013] The silicon wafer texturing device provided by the present invention can improve the efficiency and uniformity of silicon wafer texturing, which is beneficial to improving the yield rate of silicon wafer texturing process. The motor in the rotating component can drive the main shaft and the silicon wafer arranged on the main shaft to rotate slowly, and the texturing liquid and the silicon wafer can move relative to each other, which can enhance the contact between the silicon wafer and the texturing liquid, improve the reaction rate, and reduce the time required for texturing; and can improve the concentration uniformity of the texturing liquid, thereby improving the uniformity of the velvet surface. The high-frequency vibration generated by the ultrasonic component is evenly transmitted to the texturing tank, which can make the texturing liquid fully contact with the silicon wafer, use the ultrasonic cavitation effect to strengthen the solution disturbance, and effectively reduce the bubbles in the texturing liquid, so that the texturing is more uniform. The heating component is arranged on the periphery of the texturing tank to make it heat stably and evenly, which can increase the temperature of the texturing liquid and the silicon wafer, make the molecules move faster, thereby accelerating the reaction rate and improving the texturing efficiency. By setting the rotating component, the ultrasonic component and the heating component, the efficiency and uniformity of silicon wafer texturing can be effectively improved.

[0014] Preferably, the silicon wafer includes a single crystal silicon wafer, and the texturing liquid refers to a chemical solution used for texturing the surface of a single crystal silicon wafer. In the large-scale production of single crystal silicon solar cells, chemical wet etching occupies a dominant position because of its economy and cheapness. Generally, an alkaline solution is used to anisotropically etch the surface of single crystal silicon to prepare a "pyramid" velvet surface, so that the incident light is reflected multiple times on the surface of the silicon wafer, increasing the absorption of the incident light and reducing reflection, that is, reducing the reflectivity of the velvet surface, thereby helping to improve the photoelectric conversion efficiency of the single crystal silicon solar cell. The texturing liquid includes an alkaline corrosive agent and a solvent, the alkaline corrosive agent includes at least one of sodium hydroxide or potassium hydroxide, and the solvent includes at least one of water, ethanol, ethylene glycol, and isopropanol. Additives such as alkylphenol-type surfactants, EOPOEO-type block polyethers, etc. can also be added to the single crystal silicon wafer texturing liquid.

[0015] Preferably, the silicon wafer includes a polycrystalline silicon wafer, and the texturing liquid refers to a chemical solution used for texturing the surface of the polycrystalline silicon wafer. Generally, an acidic solution is used to isotropically etch the surface of the polycrystalline silicon to prepare a "honeycomb" texture surface. The texturing liquid includes an acidic corrosive agent and a solvent, the acidic corrosive agent includes nitric acid and hydrofluoric acid, and the solvent includes water.

[0016] It should be noted that the present invention does not make specific requirements or special limitations on the type of silicon wafers and the composition and content of the texturing solution. Silicon wafers and texturing solutions that have been disclosed in the prior art or not disclosed in the new technology can be used in the present invention, and new technical solutions obtained by conventional replacement also fall within the protection scope and disclosure scope of the present invention.

[0017] It is worth noting that the components in the texturing tank have a certain degree of acid and alkali corrosion resistance, can hold acidic or alkaline solutions, and can be reused.

[0018] As a preferred technical solution of the present invention, at least one detachable silicon wafer is arranged on the periphery of the main shaft, one side edge of the silicon wafer is fixed on the outer wall of the main shaft along the length direction of the main shaft, and the silicon wafers on the periphery of the main shaft are radially distributed with the main shaft as the center.

[0019] In the present invention, the silicon wafers on the periphery of the main shaft are distributed radially with the main shaft as the center. When the silicon wafers rotate slowly around the axis, the texturing liquid and the silicon wafers move relative to each other, which can enhance the contact between the silicon wafer and the texturing liquid, increase the reaction rate, and reduce the time required for texturing; and the concentration uniformity of the texturing liquid can be further improved, and the uniformity of the velvet surface is also improved accordingly.

[0020] As a preferred technical solution of the present invention, at least one fixing member is provided on the main shaft, and the fixing member is used to fix the silicon wafer.

[0021] Preferably, the spindle is provided with a guide rail, and the guide rail is provided with a buckle or a slot for fixing the silicon wafer. The motor is connected to the spindle by transmission, so as to drive the guide rail to make the silicon wafer rotate around the axis. The silicon wafer is detachable, and the silicon wafer is fixed to the spindle by a fixing member during texturing, and the silicon wafer can be removed after texturing for the next operation.

[0022] It should be noted that the present invention does not make any specific requirements or special limitations on the types of fixing parts. Fixing parts disclosed in the prior art or not disclosed in the new technology can be used in the present invention. New technical solutions obtained by conventional replacement of this structure also fall within the protection scope and disclosure scope of the present invention.

[0023] As a preferred technical solution of the present invention, the ultrasonic component includes an ultrasonic transformer and an ultrasonic transducer, the input end and the output end of the ultrasonic transformer are respectively connected to the ultrasonic transducer and the texturing tank, and the mechanical vibration generated by the ultrasonic transducer is amplified by the ultrasonic transformer and transmitted to the texturing tank.

[0024] The ultrasonic transducer includes piezoelectric ceramics and electrode sheets which are overlapped in sequence.

[0025] In the present invention, the high-frequency mechanical vibration generated by the ultrasonic transducer is evenly transmitted to the texturing tank after being amplified by the ultrasonic amplitude transformer, and the high-frequency vibration generated by the ultrasonic component is evenly transmitted to the texturing tank, so that the texturing liquid can be fully in contact with the silicon wafer, and the bubbles in the texturing liquid are reduced, and the concentration uniformity of the texturing liquid is improved, so that the texturing is more uniform. The ultrasonic component can not only amplify the displacement or speed of the particles in the component, but also gather the vibration energy and transmit it to the texturing tank, so that the texturing process is more efficient.

[0026] Preferably, the ultrasonic transducer is connected to the ultrasonic horn via a flange.

[0027] Preferably, the ultrasonic transformer is connected to the texturing tank via a buckle.

[0028] It should be noted that the present invention does not make any specific requirements or special limitations on the types of connectors. Connectors disclosed in the prior art or undisclosed in the new technology can be used in the present invention, and new technical solutions obtained by conventional replacement of this structure also fall within the protection scope and disclosure scope of the present invention.

[0029] In the present invention, the ultrasonic transducer utilizes the piezoelectric effect of piezoelectric ceramics with the same resonant frequency to convert electrical energy into mechanical vibration. As an energy conversion device, the function of the ultrasonic transducer is to convert the input electrical power into mechanical power (i.e., ultrasonic waves) and then transmit it, while it consumes a small part of the power itself. After connecting to a power source, the ultrasonic transducer can convert electrical energy into mechanical energy (sound energy).

[0030] As a preferred technical solution of the present invention, an annular cavity is formed between the inner wall of the shell and the outer wall of the texturing tank, and the heating component is arranged around the annular cavity.

[0031] In the present invention, the heating component is arranged in an annular cavity, which can provide a uniform and stable heat source, increase the temperature of the texturing liquid and the silicon wafer, make the molecules move faster, and thus accelerate the reaction rate and improve the texturing efficiency; and the heating component is arranged in the annular cavity to improve safety and prevent operators from being injured.

[0032] Preferably, the heating component is a spiral heating tube, which surrounds the outer periphery of the texturing tank and is arranged in the annular cavity, and can provide a uniform and stable heat source. It should be noted that the present invention does not make specific requirements and special limitations on the shape and type of the heating component. The heating components disclosed in the prior art or undisclosed in the new technology can be used in the present invention, and the new technical solution obtained by conventional replacement of this structure also falls within the protection scope and disclosure scope of the present invention.

[0033] As a preferred technical solution of the present invention, a cover plate is provided at the top opening of the shell, and the motor is located above the cover plate and fixed on the cover plate.

[0034] A base with a cavity is arranged below the shell, and the ultrasonic component is arranged inside the base.

[0035] In the present invention, the cover plate can prevent the texturing liquid from splashing and foreign matter from entering the texturing liquid, and the motor is connected to the main shaft through a small hole in the center of the cover plate. The base can accommodate the ultrasonic component and play a supporting role in the overall device.

[0036] As a preferred technical solution of the present invention, the silicon wafer texturing device further includes a controller, and the controller is electrically connected to the rotating component, the ultrasonic component and the heating component independently and separately.

[0037] In a second aspect, the present invention provides a method for texturing a silicon wafer, the method comprising: fixing the silicon wafer on a main shaft, injecting texturing liquid into a texturing tank; simultaneously turning on an ultrasonic component, a heating component and a motor, the motor drives the main shaft and the silicon wafer to rotate around the axis, and texturing the silicon wafer.

[0038] As a preferred technical solution of the present invention, the rotation speed of the silicon wafer is 0.1-2r / min, for example, it can be 0.1r / min, 0.2r / min, 0.3r / min, 0.4r / min, 0.5r / min, 0.6r / min, 0.7r / min, 0.75r / min, 0.8r / min, 0.9r / min, 1r / min, 1.1r / min, 1.2r / min, 1.3r / min, 1.4r / min, 1.5r / min, 1.6r / min, 1.7r / min, 1.8r / min, 1.9r / min, 2r / min, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, and it is further preferably 0.5-1r / min.

[0039] The rotation speed of the silicon wafer affects the transport speed of the reactants and products during the reaction process. Therefore, the present invention has specific requirements and special limitations on the rotation speed range of the silicon wafer, requiring the rotation speed of the silicon wafer to be between 0.1 and 2 r / min. When the rotation speed of the silicon wafer exceeds 2 r / min, the transport speed is fast, but more bubbles may be generated in the texturing liquid, reducing the uniformity of the reaction, which is not conducive to texturing, and the thin silicon wafer is easily damaged; when the rotation speed of the silicon wafer is lower than 0.1 / min, the transport speed of the reactants and products is slow, it is difficult to increase the reaction rate, and the texturing cycle is long.

[0040] The heating component heats the texturing liquid to 20-100°C, for example, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, and 20-80°C is more preferably.

[0041] Temperature directly affects the texturing reaction. Generally speaking, the higher the temperature, the faster the reaction. Therefore, the present invention has specific requirements and special limitations on the temperature range of texturing. When the temperature is lower than 20°C, the texturing reaction progresses slowly and the cycle is long; but when the temperature is higher than 100°C, the continuity of the velvet surface is reduced, the reaction rate is too fast, and it is difficult to control. At the same time, there are problems such as high energy consumption.

[0042] The heating rate of the texturing liquid is 5 to 15°C / min, for example, it can be 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, 11°C / min, 12°C / min, 13°C / min, 14°C / min, 15°C / min, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, and 5 to 8°C / min is more preferably used.

[0043] The vibration frequency of the ultrasonic wave emitted by the ultrasonic component is 28 to 80 kHz, for example, it can be 28 kHz, 30 kHz, 35 kHz, 40 kHz, 45 kHz, 50 kHz, 55 kHz, 60 kHz, 65 kHz, 70 kHz, 75 kHz, 80 kHz, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0044] The texturing time of the silicon wafer is 8 to 15 minutes, for example, it can be 8 minutes, 8.5 minutes, 9 minutes, 9.5 minutes, 10 minutes, 10.5 minutes, 11 minutes, 11.5 minutes, 12 minutes, 12.5 minutes, 13 minutes, 13.5 minutes, 14 minutes, 14.5 minutes, and 15 minutes, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0046] In a third aspect, the present invention provides an application of the silicon wafer texturing device as described in the first aspect, wherein the silicon wafer texturing device is used for photovoltaic texturing.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The silicon wafer texturing device provided by the present invention can improve the efficiency and uniformity of silicon wafer texturing, which is beneficial to improving the yield rate of silicon wafer texturing process. The motor in the rotating component can drive the main shaft and the silicon wafer arranged on the main shaft to rotate slowly, and the texturing liquid and the silicon wafer can move relative to each other, which can enhance the contact between the silicon wafer and the texturing liquid, improve the reaction rate, and reduce the time required for texturing; and can improve the concentration uniformity of the texturing liquid, thereby improving the uniformity of the velvet surface. The high-frequency vibration generated by the ultrasonic component is evenly transmitted to the texturing tank, which can make the texturing liquid fully contact with the silicon wafer, use the ultrasonic cavitation effect to strengthen the solution disturbance, and effectively reduce the bubbles in the texturing liquid, so that the texturing is more uniform. The heating component is arranged on the periphery of the texturing tank to make it heat stably and evenly, which can increase the temperature of the texturing liquid and the silicon wafer, make the molecules move faster, thereby accelerating the reaction rate and improving the texturing efficiency. By setting the rotating component, the ultrasonic component and the heating component, the efficiency and uniformity of silicon wafer texturing can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A front view of a schematic structural diagram of a silicon wafer texturing device provided in a specific embodiment of the present invention;

[0050] Figure 2A top view of a schematic structural diagram of a silicon wafer texturing device provided in a specific embodiment of the present invention;

[0051] Figure 3 A schematic diagram of the structure of an ultrasonic transducer provided in a specific embodiment of the present invention;

[0052] Among them, 1-ultrasonic transducer; 2-ultrasonic amplitude transformer; 3-main shaft; 4-base; 5-shell; 6-heating component; 7-silicon wafer; 8-cover plate; 9-motor; 10-electrode sheet; 11-piezoelectric ceramic. DETAILED DESCRIPTION

[0053] It should be understood that, in the description of the present invention, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0054] It should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0055] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0056] In a specific embodiment, the present invention provides a silicon wafer texturing device, the silicon wafer texturing device is as follows Figure 1 As shown, it comprises a shell 5 and a texturing tank located in the shell 5, a rotating component is arranged in the texturing tank, and an ultrasonic component and a heating component 6 are arranged below and around the texturing tank respectively;

[0057] The rotating assembly includes a main shaft 3 located inside the texturing tank, and a motor 9 drivingly connected to the main shaft 3;

[0058] The motor 9 drives the main shaft 3 and the silicon wafer 7 disposed on the main shaft 3 to rotate around the axis;

[0059] The texturing tank contains texturing liquid, and the silicon wafer 7 is immersed in the texturing liquid.

[0060] The silicon wafer texturing device provided by the present invention can improve the efficiency and uniformity of silicon wafer texturing, which is conducive to improving the yield rate of silicon wafer texturing process. The motor 9 in the rotating component can drive the main shaft 3 and the silicon wafer 7 arranged on the main shaft 3 to rotate slowly, and the texturing liquid and the silicon wafer 7 have relative movement, which can enhance the contact between the silicon wafer 7 and the texturing liquid, improve the reaction rate, and reduce the time required for texturing; and can improve the concentration uniformity of the texturing liquid, thereby improving the uniformity of the velvet surface. The high-frequency vibration generated by the ultrasonic component is evenly transmitted to the texturing tank, which can make the texturing liquid fully contact with the silicon wafer 7, use the ultrasonic cavitation effect to strengthen the solution disturbance, and effectively reduce the bubbles in the texturing liquid, so that the texturing is more uniform. The heating component 6 is arranged on the periphery of the texturing tank to make it heat stably and evenly, which can increase the temperature of the texturing liquid and the silicon wafer 7, make the molecules move faster, thereby accelerating the reaction rate and improving the texturing efficiency. By setting the rotating component, the ultrasonic component and the heating component 6, the efficiency and uniformity of the texturing of the silicon wafer 7 can be effectively improved.

[0061] Preferably, the silicon wafer 7 includes a single crystal silicon wafer, and the texturing liquid refers to a chemical solution used for texturing the surface of a single crystal silicon wafer. In the large-scale production of single crystal silicon solar cells, chemical wet etching occupies a dominant position because of its economy and cheapness. Generally, an alkaline solution is used to anisotropically etch the surface of single crystal silicon to prepare a "pyramid" velvet surface, so that the incident light is reflected multiple times on the surface of the single crystal silicon wafer, increasing the absorption of the incident light and reducing reflection, that is, reducing the reflectivity of the velvet surface, thereby helping to improve the photoelectric conversion efficiency of the single crystal silicon solar cell. The texturing liquid includes an alkaline corrosive agent and a solvent, the alkaline corrosive agent includes at least one of sodium hydroxide or potassium hydroxide, and the solvent includes at least one of water, ethanol, ethylene glycol, and isopropanol. Additives such as alkylphenol-type surfactants, EOPOEO-type block polyethers, etc. can also be added to the single crystal silicon wafer texturing liquid.

[0062] Preferably, the silicon wafer 7 comprises a polycrystalline silicon wafer, and the texturing liquid refers to a chemical solution used for texturing the surface of the polycrystalline silicon wafer. Generally, an acidic solution is used to isotropically etch the surface of the polycrystalline silicon to prepare a "honeycomb" texture surface. The texturing liquid comprises an acidic corrosive agent and a solvent, the acidic corrosive agent comprises nitric acid and hydrofluoric acid, and the solvent comprises water.

[0063] It should be noted that the present invention does not make specific requirements or special limitations on the type of silicon wafer 7 and the composition and content of the texturing liquid. Silicon wafers and texturing liquids that have been disclosed in the prior art or not disclosed in the new technology can be used in the present invention, and new technical solutions obtained by conventional replacement also fall within the protection scope and disclosure scope of the present invention.

[0064] It is worth noting that the components in the texturing tank have a certain degree of acid and alkali corrosion resistance, can hold acidic or alkaline solutions, and can be reused.

[0065] Furthermore, at least one detachable silicon wafer 7 is arranged on the periphery of the spindle 3, and one side edge of the silicon wafer 7 is fixed to the outer wall of the spindle 3 along the length direction of the spindle 3. The silicon wafers 7 on the periphery of the spindle 3 are radially distributed with the spindle 3 as the center, such as Figure 2 shown.

[0066] In the present invention, the silicon wafers 7 on the periphery of the main shaft 3 are radially distributed with the main shaft 3 as the center. When the silicon wafer 7 slowly rotates around the axis, the texturing liquid and the silicon wafer 7 move relative to each other, which can enhance the contact between the silicon wafer 7 and the texturing liquid, increase the reaction rate, and reduce the time required for texturing; and the concentration uniformity of the texturing liquid can be further improved, and the uniformity of the velvet surface is also improved accordingly.

[0067] Furthermore, at least one fixing member is disposed on the main shaft 3 , and the fixing member is used to fix the silicon wafer 7 .

[0068] Preferably, the spindle 3 is provided with a guide rail, and the guide rail is provided with a buckle or a slot for fixing the silicon wafer 7. The motor 9 is connected to the spindle 3 by transmission, so as to drive the guide rail to make the silicon wafer 7 rotate around the axis. The silicon wafer 7 is detachable, and the silicon wafer 7 is fixed to the spindle 3 by a fixing member during texturing, and the silicon wafer 7 can be removed after texturing for the next operation.

[0069] It should be noted that the present invention does not make any specific requirements or special limitations on the types of fixing parts. Fixing parts disclosed in the prior art or not disclosed in the new technology can be used in the present invention. New technical solutions obtained by conventional replacement of this structure also fall within the protection scope and disclosure scope of the present invention.

[0070] Furthermore, the ultrasonic component includes an ultrasonic horn 2 and an ultrasonic transducer 1, such as Figure 1 As shown, the input end and the output end of the ultrasonic horn 2 are respectively connected to the ultrasonic transducer 1 and the texturing tank. The mechanical vibration generated by the ultrasonic transducer 1 is amplified by the ultrasonic horn 2 and transmitted to the texturing tank.

[0071] like Figure 3 As shown, the ultrasonic transducer 1 includes a piezoelectric ceramic 11 and an electrode sheet 10 which are overlapped in sequence.

[0072] In the present invention, the high-frequency mechanical vibration generated by the ultrasonic transducer 1 is evenly transmitted to the texturing tank after being amplified by the ultrasonic horn 2. The high-frequency vibration generated by the ultrasonic component is evenly transmitted to the texturing tank, which can make the texturing liquid fully contact with the silicon wafer 7, reduce the bubbles in the texturing liquid, and improve the concentration uniformity of the texturing liquid, so that the texturing is more uniform. The ultrasonic component can not only amplify the displacement or speed of the particles in the component, but also gather the vibration energy and transmit it to the texturing tank, so that the texturing process is more efficient.

[0073] Preferably, the ultrasonic transducer 1 is connected to the ultrasonic horn 2 via a flange.

[0074] Preferably, the ultrasonic transformer 2 is connected to the texturing tank via a buckle.

[0075] It should be noted that the present invention does not make any specific requirements or special limitations on the types of connectors. Connectors disclosed in the prior art or undisclosed in the new technology can be used in the present invention, and new technical solutions obtained by conventional replacement of this structure also fall within the protection scope and disclosure scope of the present invention.

[0076] In the present invention, the ultrasonic transducer utilizes the piezoelectric effect of the piezoelectric ceramic 11 with the same resonant frequency to convert electrical energy into mechanical vibration. As an energy conversion device, the function of the ultrasonic transducer is to convert the input electrical power into mechanical power (i.e., ultrasonic waves) and then transmit it, while it consumes a small part of the power itself. After connecting to the power supply, the ultrasonic transducer 1 can convert electrical energy into mechanical energy (sound energy).

[0077] Furthermore, an annular cavity is formed between the inner wall of the shell 5 and the outer wall of the texturing tank, and the heating component 6 is disposed in the annular cavity.

[0078] In the present invention, if Figure 1 As shown, the heating component 6 is arranged in an annular cavity, which can provide a uniform and stable heat source, increase the temperature of the texturing liquid and the silicon wafer 7, make the molecules move faster, and thus accelerate the reaction rate and improve the texturing efficiency; and the heating component 6 is arranged in the annular cavity to improve safety and prevent operators from being injured.

[0079] Preferably, the heating component 6 is a spiral heating tube, which surrounds the outer periphery of the texturing tank and is arranged in the annular cavity, and can provide a uniform and stable heat source. It should be noted that the present invention does not make specific requirements and special limitations on the shape and type of the heating component 6. The heating components disclosed in the prior art or undisclosed in the new technology can be used in the present invention, and the new technical solution obtained by conventional replacement of this structure also falls within the protection scope and disclosure scope of the present invention.

[0080] Furthermore, a cover plate 8 is provided at the top opening of the housing 5 , and the motor 9 is located above the cover plate 8 and fixed on the cover plate 8 .

[0081] A base 4 having a cavity is disposed below the housing 5, and the ultrasonic component is disposed inside the base 4. Figure 1 shown.

[0082] In the present invention, the cover plate 8 can prevent the texturing liquid from splashing and foreign matter from entering the texturing liquid, and the motor 9 is connected to the main shaft 3 through the small hole in the center of the cover plate 8. The base 4 can accommodate the ultrasonic component and play a supporting role in the overall device.

[0083] Furthermore, the silicon wafer texturing device also includes a controller, and the controller is electrically connected to the rotating component, the ultrasonic component and the heating component 6 independently and separately.

[0084] In another specific embodiment, the present invention provides a texturing method for the silicon wafer texturing device provided in the above specific embodiment, and the texturing method specifically comprises the following steps:

[0085] Fix the silicon wafer 7 on the main shaft 3 and inject texturing liquid into the texturing tank; turn on the ultrasonic component, heating component 6 and motor 9 at the same time, the heating component 6 heats the texturing liquid to 20-100°C at a rate of 5-15°C / min, the vibration frequency of the ultrasonic wave emitted by the ultrasonic component is 28-80kHz, and the silicon wafer 7 rotates around the axis at a speed of 0.1-2r / min driven by the motor 9 to perform texturing; the texturing time of the silicon wafer 7 is 8-15min.

[0086] Example 1

[0087] This embodiment provides a method for texturing a single crystal silicon wafer, which specifically includes the following steps:

[0088] Fix the silicon wafer 7 on the main shaft 3, and inject texturing liquid into the texturing tank. The texturing liquid contains 2% potassium hydroxide, 1% additives, and the rest is water, calculated by mass percentage of the solution. The ultrasonic component, heating component 6, and motor 9 are turned on at the same time. The heating component 6 heats the texturing liquid to 65°C with a heating rate of 8°C / min. The vibration frequency of the ultrasonic wave emitted by the ultrasonic component is 50kHz. The motor 9 drives the silicon wafer 7 to rotate around the axis at a speed of 0.75r / min for texturing. The texturing time of the silicon wafer 7 is 10min.

[0089] Example 2

[0090] This embodiment provides a method for texturing a single crystal silicon wafer, which specifically includes the following steps:

[0091] Fix the silicon wafer 7 on the main shaft 3, and inject texturing liquid into the texturing tank. The texturing liquid contains 2% potassium hydroxide, 1% additives, and the rest is water, calculated by mass percentage of the solution. The ultrasonic component, heating component 6 and motor 9 are turned on at the same time. The heating component 6 heats the texturing liquid to 20°C with a heating rate of 5°C / min. The vibration frequency of the ultrasonic wave emitted by the ultrasonic component is 50kHz. The motor 9 drives the silicon wafer 7 to rotate around the axis at a speed of 1r / min for texturing. The texturing time of the silicon wafer 7 is 12min.

[0092] Example 3

[0093] This embodiment provides a method for texturing a single crystal silicon wafer, which specifically includes the following steps:

[0094] Fix the silicon wafer 7 on the main shaft 3, and inject texturing liquid into the texturing tank. The texturing liquid contains 2% sodium hydroxide, 1% additives and the rest is water according to the mass percentage of the solution. The ultrasonic component, heating component 6 and motor 9 are turned on at the same time. The heating component 6 heats the texturing liquid to 20°C with a heating rate of 5°C / min. At the same time, the ultrasonic component is turned on. The vibration frequency of the ultrasonic wave emitted by the ultrasonic component is 28kHz. The motor 9 drives the silicon wafer 7 to rotate around the axis at a speed of 2r / min for texturing. The texturing time of the silicon wafer 7 is 15min.

[0095] Example 4

[0096] This embodiment provides a method for texturing a single crystal silicon wafer, which specifically includes the following steps:

[0097] Fix the silicon wafer 7 on the main shaft 3, and inject texturing liquid into the texturing tank. The texturing liquid contains 2% potassium hydroxide, 1% additives and the rest is water according to the mass percentage of the solution. The ultrasonic component, heating component 6 and motor 9 are turned on at the same time. The heating component 6 heats the texturing liquid to 80°C with a heating rate of 10°C / min. At the same time, the ultrasonic component is turned on. The vibration frequency of the ultrasonic wave emitted by the ultrasonic component is 40kHz. The motor 9 drives the silicon wafer 7 to rotate around the axis at a speed of 0.5r / min for texturing. The texturing time of the silicon wafer 7 is 10min.

[0098] Example 5

[0099] This embodiment provides a method for texturing a single crystal silicon wafer, which specifically includes the following steps:

[0100] Fix the silicon wafer 7 on the main shaft 3, and inject texturing liquid into the texturing tank. The texturing liquid contains 2% potassium hydroxide, 1% additives, and the rest is water, calculated by mass percentage of the solution. The ultrasonic component, heating component 6, and motor 9 are turned on at the same time. The heating component 6 heats the texturing liquid to 100°C with a heating rate of 15°C / min. The vibration frequency of the ultrasonic wave emitted by the ultrasonic component is 80kHz. The motor 9 drives the silicon wafer 7 to rotate around the axis at a speed of 0.1r / min for texturing. The texturing time of the silicon wafer 7 is 8min.

[0101] Example 6

[0102] This embodiment provides a method for texturing a single crystal silicon wafer, which is different from the first embodiment in that the motor 9 drives the silicon wafer 7 to rotate around the axis at a speed of 0.05 r / min to perform texturing. The remaining operation steps and process parameters are exactly the same as those of the first embodiment.

[0103] Example 7

[0104] This embodiment provides a method for texturing a single crystal silicon wafer, which differs from the first embodiment in that the motor 9 drives the silicon wafer 7 to rotate around the axis at a speed of 2.5 r / min to perform texturing. The remaining operation steps and process parameters are exactly the same as those of the first embodiment.

[0105] Example 8

[0106] This embodiment provides a method for texturing a single crystal silicon wafer, which is different from the first embodiment in that the heating component 6 heats the texturing liquid to 15° C. The remaining operation steps and process parameters are exactly the same as those of the first embodiment.

[0107] Example 9

[0108] This embodiment provides a method for texturing a single crystal silicon wafer, which is different from the first embodiment in that the heating component 6 heats the texturing liquid to 105° C. The remaining operation steps and process parameters are exactly the same as those of the first embodiment.

[0109] Comparative Example 1

[0110] This comparative example provides a silicon wafer texturing device, which differs in structure from the silicon wafer texturing device provided in the specific implementation method in that the motor 9 is omitted, so that the silicon wafer 7 cannot rotate around the axis, and the remaining structures and connection relationships are exactly the same as those in the specific implementation method.

[0111] The texturing method provided in Example 1 is used in the above device for texturing. The difference is that since the motor 9 is omitted, the silicon wafer 7 cannot rotate around the axis during texturing. The remaining operating steps and process parameters are exactly the same as those in Example 1.

[0112] Comparative Example 2

[0113] This comparative example provides a silicon wafer texturing device, which differs in structure from the silicon wafer texturing device provided in the specific implementation manner in that the heating component 6 is omitted, and the remaining structures and connection relationships are exactly the same as those in the specific implementation manner.

[0114] In the above device, the texturing method provided in Example 1 is used for texturing. The difference is that since the heating component 6 is omitted, heating cannot be performed during texturing. The remaining operating steps and process parameters are exactly the same as those in Example 1.

[0115] Comparative Example 3

[0116] This comparative example provides a silicon wafer texturing device, which differs in structure from the silicon wafer texturing device provided in the specific implementation manner in that the ultrasonic component is omitted, and the remaining structures and connection relationships are exactly the same as those in the specific implementation manner.

[0117] The texturing method provided in Example 1 is used in the above-mentioned device for texturing. The difference is that since the ultrasonic component is omitted, ultrasound cannot be used during texturing. The remaining operating steps and process parameters are exactly the same as those in Example 1.

[0118] The textured silicon wafer 7 in Examples 1-9 and Comparative Examples 1-3 was tested for textured reflectivity, and the results are shown in Table 1.

[0119] Table 1

[0120]

[0121]

[0122] From the comparison of Example 1, Example 6 and Example 7, it can be seen that if the rotation speed of the silicon wafer is too low or too high, it will have an adverse effect on the velvet surface, and the velvet reflectivity of the silicon wafer will increase, which will reduce the conversion efficiency of the silicon solar cell. The main reason is that the rotation speed of the silicon wafer affects the transportation speed of the reactants and products during the reaction. When the rotation speed is high, the transportation speed is fast, but more bubbles may be generated in the velvet liquid, which reduces the uniformity of the solution concentration and is not conducive to velvet production; when the rotation speed is low, the transportation speed of the reactants and products is slow, it is difficult to increase the reaction rate, and the velvet production cycle is long.

[0123] From the comparison between Example 1, Example 8 and Example 9, it can be seen that the temperature of the texturing process is too low or too high, which will have an adverse effect on the velvet surface. The main reason is that the temperature directly affects the texturing reaction. Generally speaking, the higher the temperature, the faster the reaction. When the temperature is too low, the texturing reaction progresses slowly and the cycle is long; but when the temperature is too high, the continuity of the velvet surface is reduced, the reaction rate is too fast, and it is difficult to control.

[0124] It can be seen from Example 1 and Comparative Example 1 that when texturing is performed without rotating the silicon wafer, the reflectivity of the velvet surface increases and the uniformity of the velvet surface is low. This is because when the silicon wafer rotates slowly, the texturing liquid and the silicon wafer move relative to each other, which can enhance the contact between the silicon wafer and the texturing liquid, increase the reaction rate, and reduce the time required for texturing; and can improve the concentration uniformity of the texturing liquid, thereby improving the uniformity of the velvet surface.

[0125] It can be seen from Example 1 and Comparative Example 2 that when texturing is performed without heating, the reflectivity of the suede surface increases and the suede surface effect becomes worse. This is because the heating component can increase the temperature of the texturing liquid and the silicon wafer, making the molecules move faster, thereby accelerating the reaction rate and improving the texturing efficiency.

[0126] It can be seen from Example 1 and Comparative Example 3 that when texturing is performed without ultrasound, the reflectivity of the suede surface increases and the suede effect becomes worse. This is because the high-frequency vibration generated by the ultrasonic component is evenly transmitted to the texturing tank, which allows the texturing liquid to fully contact the silicon wafer, reduces bubbles in the texturing liquid, and improves the concentration uniformity of the texturing liquid, thereby making the texturing more uniform.

[0127] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A texturing method for a silicon wafer texturing device, characterized in that: The silicon wafer texturing device comprises a shell and a texturing tank located in the shell, a rotating component is arranged in the texturing tank, and an ultrasonic component and a heating component are arranged below and around the texturing tank respectively; The rotating assembly includes a main shaft located inside the texturing tank, and a motor drivingly connected to the main shaft; The motor drives the main shaft and the silicon wafer disposed on the main shaft to rotate around the axis; One side edge of the silicon wafer is fixed to the outer wall of the main shaft along the length direction of the main shaft, and the silicon wafers on the periphery of the main shaft are radially distributed with the main shaft as the center; The texturing tank contains a texturing liquid, and the silicon wafer is immersed in the texturing liquid; The texturing method comprises: Fix the silicon wafer on the main shaft and inject the texturing liquid into the texturing tank; At the same time, the ultrasonic component, the heating component and the motor are turned on, and the motor drives the main shaft and the silicon wafer to rotate around the axis to make the silicon wafer textured; The rotation speed of the silicon wafer is 0.5-1 r / min; The heating component heats the texturing liquid to 20-80°C.

2. The texturing method according to claim 1, characterized in that: At least one detachable silicon wafer is arranged on the outer periphery of the main shaft.

3. The texturing method according to claim 1, characterized in that: At least one fixing member is arranged on the main shaft, and the fixing member is used to fix the silicon wafer.

4. The texturing method according to claim 1, characterized in that: The ultrasonic component includes an ultrasonic horn and an ultrasonic transducer. The input end and the output end of the ultrasonic horn are respectively connected to the ultrasonic transducer and the texturing tank. The mechanical vibration generated by the ultrasonic transducer is amplified by the ultrasonic horn and transmitted to the texturing tank.

5. The texturing method according to claim 4, characterized in that: The ultrasonic transducer includes piezoelectric ceramics and electrode sheets which are overlapped in sequence.

6. The texturing method according to claim 1, characterized in that: An annular cavity is formed between the inner wall of the shell and the outer wall of the texturing tank, and the heating component is arranged in the annular cavity.

7. The texturing method according to claim 1, characterized in that: A cover plate is disposed at the top opening of the shell, and the motor is located above the cover plate and fixed on the cover plate.

8. The texturing method according to claim 1, characterized in that: A base with a cavity is arranged below the shell, and the ultrasonic component is arranged inside the base.

9. The texturing method according to claim 1, characterized in that: The silicon wafer texturing device also includes a controller.

10. The texturing method according to claim 9, characterized in that: The controller is electrically connected to the rotating component, the ultrasonic component and the heating component independently and separately.

11. The texturing method according to claim 1, characterized in that: The heating rate of the texturing liquid is 5-15°C / min.

12. The texturing method according to claim 11, characterized in that: The heating rate of the texturing liquid is 5-8°C / min.

13. The texturing method according to claim 1, characterized in that: The vibration frequency of the ultrasonic wave emitted by the ultrasonic component is 28-80 kHz.

14. The texturing method according to claim 1, characterized in that: The texturing time of the silicon wafer is 8 to 15 minutes.

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