Silicon rod cutting method, silicon wafer, battery piece, photovoltaic module and photovoltaic power generation system

Abstract

The invention belongs to the field of photovoltaic technology, and discloses a silicon rod cutting method, a silicon wafer, a battery piece, a photovoltaic module and a photovoltaic power generation system. The method comprises the steps that at least two silicon rods are stacked and fixed to a workbench of cutting equipment in the first direction; and controlling a wire net of the cutting equipment to cut the silicon rod according to a preset process program of the cutting equipment. The first direction is the feeding direction of the workbench or the wire net; the cutting lines in the line net move in the second direction and are arranged in the third direction; the three directions are vertical in pairs; the maximum size of the silicon rod in the first direction is L1, the maximum size of the silicon rod in the second direction is L2, and the size of the silicon rod in the third direction is L3; l1 < L2 < L3. The wire net cuts at least two silicon rods at a time, the cutting efficiency is improved, the consumption of consumables such as cutting wires is reduced, and the cost is reduced. The shortest edge of the silicon rod is in the feeding direction, the feeding distance is minimum while at least two silicon rods are cut at a time, and it is guaranteed that the cutting efficiency is optimal.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a silicon rod cutting method, silicon wafers, battery slices, photovoltaic modules and photovoltaic power generation systems. Background Art

[0002] Silicon wafers are a key material in the production of solar cells. The typical silicon wafer processing process involves crystal growth, cutting, squaring, outer diameter barrel grinding, flat grinding, slicing, cleaning, and packaging. As a key step in the silicon wafer processing process, silicon wafer slicing has a direct impact on the overall efficiency and quality of the entire silicon wafer production process.

[0003] In the prior art, when cutting a rectangular silicon ingot into wafers, the ingot is secured to a plastic carrier plate, which is then inverted and fixed to a cutting machine's feed table. Before cutting begins, the ingot is positioned above the cutting machine's wire mesh. During cutting, the ingot is fed downward by the feed table, while the wire mesh moves in the cutting direction, separating the ingot into a set of wafers.

[0004] The existing technology for cutting silicon ingots suffers from low cutting efficiency, resulting in wafer yields that fail to meet production needs and impacting the yield of photovoltaic modules. Each ingot cut consumes a large amount of plastic sheet, and the wire mesh may need to be readjusted or re-laid between the completion of the current ingot cut and the next. This results in high consumption of the diamond wire that makes up the wire mesh and high cutting costs.

[0005] Therefore, there is an urgent need for a silicon rod cutting method, silicon wafers, solar cells, photovoltaic modules and photovoltaic power generation systems to solve the problems existing in the related technologies. Summary of the Invention

[0006] The purpose of the present invention is to provide a silicon rod cutting method, silicon wafers, solar cells, photovoltaic modules and photovoltaic power generation system, which can improve the cutting efficiency of silicon rods, speed up the production speed of photovoltaic modules, reduce the use of consumables in the cutting process, reduce production costs, and achieve cost reduction and efficiency improvement.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, a silicon rod cutting method is provided, comprising:

[0009] Stacking and fixing at least two silicon rods along a first direction on a workbench of a cutting device;

[0010] Controlling the wire mesh of the cutting device to cut the silicon rod according to a preset process program of the cutting device;

[0011] Wherein, the first direction is the feeding direction of the workbench or the wire web; the cutting lines in the wire web move along the second direction and are arranged along the third direction; the first direction, the second direction and the third direction are perpendicular to each other;

[0012] The maximum dimension of the silicon rod in the first direction is L1, the maximum dimension of the silicon rod in the second direction is L2, and the dimension of the silicon rod in the third direction is L3; L1<L2<L3.

[0013] As an optional solution of the silicon rod cutting method provided by the present invention, the feed speed of the workbench along the first direction is obtained according to the preset process program;

[0014] controlling the movement of the worktable according to the feed speed;

[0015] Wherein, the feed speed ranges from 100 μm / min to 2500 μm / min.

[0016] As an optional solution of the silicon rod cutting method provided by the present invention, the linear speed of the cutting line is obtained according to the preset process program;

[0017] controlling the movement of the cutting wire according to the wire speed;

[0018] Wherein, the linear speed ranges from 1300 m / min to 2400 m / min.

[0019] As an optional solution of the silicon rod cutting method provided by the present invention, the side of the silicon rod facing away from the workbench is the cutting surface, and the side of the silicon rod facing the workbench is the cutting surface;

[0020] The preset process program includes a first process flow and a second process flow corresponding to each silicon rod;

[0021] Cutting the current silicon rod using the first process flow and the second process flow in sequence; wherein, when executing the second process flow, the cutting line passes through the cut surface of the current silicon rod;

[0022] The feed speed of the workbench in the second process flow is in the range of 100 μm / min to 500 μm / min, and is less than the feed speed of the workbench in the first process flow;

[0023] The line speed in the second process flow ranges from 1100 m / min to 1500 m / min, and is less than the line speed in the first process flow.

[0024] As an optional solution of the silicon rod cutting method provided by the present invention, the feed length and return length of the cutting line are obtained according to the preset process program;

[0025] controlling the cutting wire movement according to the feeding length and the returning length;

[0026] The feeding length ranges from 800 m to 1100 m.

[0027] As an optional solution of the silicon rod cutting method provided by the application, the returning length ranges from 600 m to 2200 m.

[0028] As an optional solution of the silicon rod cutting method provided by the application,

[0029] acquiring a feeding position of the workbench;

[0030] adopting a new cutting wire to cut before the workbench reaches a target feeding position; the new cutting wire is a cutting wire that has not been used;

[0031] adopting an old cutting wire to cut after the workbench reaches the target feeding position; the old cutting wire is a cutting wire that has been used before reaching the target feeding position.

[0032] As an optional solution of the silicon rod cutting method provided by the application, during the process that the workbench reaches the target feeding position, the feeding wheel of the cutting device is controlled to deliver M1 length of the new cutting wire to the winding wheel;

[0033] after the workbench reaches the target feeding position, the winding wheel is controlled to deliver M2 length of the old cutting wire to the feeding wheel;

[0034] wherein, when the workbench reaches the target feeding position, M3 length of the old cutting wire is wound on the winding wheel, and M1>M3>M2.

[0035] As an optional solution of the silicon rod cutting method provided by the application, the distance between the target feeding position and an initial feeding position accounts for 90% to 97% of a total feeding distance;

[0036] wherein, the total feeding distance is the distance between a final feeding position and the initial feeding position.

[0037] As an optional solution of the silicon rod cutting method provided by the application, the cutting device comprises two first wire guide wheels arranged at intervals; the cutting wire is wound on the two first wire guide wheels and forms the wire net between the two first wire guide wheels;

[0038] the tension of the wire net on the two first wire guide wheels is controlled to be 3.1 N to 3.6 N.

[0039] As an optional solution of the silicon rod cutting method provided by the present invention, the step of stacking and fixing at least two silicon rods along a first direction on a workbench of a cutting device includes:

[0040] Fix the pad to the carrier;

[0041] bonding at least two silicon rods in sequence along the first direction on a side of the backing plate facing away from the carrier;

[0042] The carrier is inverted and fixed on the workbench so that the silicon rods are located below the workbench.

[0043] In a second aspect, a silicon wafer is provided, which is formed by cutting using the silicon rod cutting method as described above.

[0044] In a third aspect, a battery cell is provided, which is prepared using the silicon wafer as described above.

[0045] In a fourth aspect, a photovoltaic module is provided, comprising the cell as described above.

[0046] In a fifth aspect, a photovoltaic power generation system is provided, comprising the photovoltaic assembly as described above.

[0047] Beneficial effects of the present invention:

[0048] The present invention provides a method for cutting silicon rods, wherein the maximum dimension L1 of the silicon rods in a first direction is smaller than the maximum dimension L2 of the silicon rods in a second direction, which is smaller than the maximum dimension L3 of the silicon rods in a third direction. Specifically, the edge of the silicon rods along the first direction is the shortest side. At least two silicon rods are stacked and fixed on a workbench along the first direction, and then cut using a wire mesh of a cutting device. During cutting, the wire mesh's cutting lines move along the second direction, ultimately cutting the multiple silicon rods into multiple silicon wafers with a long side dimension L2 and a short side dimension L1. Because the wire mesh can cut at least two silicon rods at a time, the cutting efficiency of the silicon rods is improved, the supply of silicon wafers is increased, the amount of wire mesh required for laying out the silicon rods and the amount of cutting wire required for cutting the silicon rods is reduced, the amount of consumables and cutting fluid used during the cutting process is reduced, and production costs are reduced. Furthermore, the silicon rods are stacked along their shortest sides, with their shortest sides serving as the feed direction. This minimizes the feed distance while cutting at least two silicon rods at a time, ensuring optimal cutting efficiency. In addition, when the cutting wire comes out of one silicon rod and cuts into another silicon rod, the movement of the cutting wire is continuous and stable, which can ensure the quality of the silicon rod cutting surface.

[0049] The present invention also provides a silicon wafer, which is formed by cutting using the above-mentioned silicon rod cutting method, and can effectively improve the cutting efficiency while ensuring the cutting quality, thereby increasing the supply of silicon wafers.

[0050] The application further provides a battery piece, a photovoltaic module and a photovoltaic power generation system, the battery piece is prepared by using the silicon piece, the production efficiency of the battery piece is improved while the quality of the battery piece is ensured, and the production efficiency of the photovoltaic module containing the battery piece is improved, and the construction process of the photovoltaic power generation system is accelerated. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of the contents of the embodiments of the present application and the drawings.

[0052] Figure 1 is a flow chart of the silicon rod cutting method provided by the specific embodiment of the present application;

[0053] Figure 2 is a schematic diagram of two silicon rods fixed on a carrier provided by the specific embodiment of the present application;

[0054] Figure 3 is a structural schematic diagram of a silicon rod provided by the specific embodiment of the present application.

[0055] In the drawings:

[0056] 1, silicon rod; 2, wire mesh; 3, adhesive; 4, backing plate; 5, carrier;

[0057] 11, cutting-in surface; 12, cutting-out surface. DETAILED DESCRIPTION

[0058] The present application will be further described in detail below in combination with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all the structures.

[0059] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0060] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0061] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are used to refer to positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0062] In this embodiment, the term "and / or" simply describes the association relationship between associated objects, indicating that three possible relationships exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this invention generally indicates that the associated objects are in an "or" relationship.

[0063] In the embodiments of the present invention, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted.

[0064] like Figure 1 As shown, this embodiment provides a silicon rod cutting method that can improve the cutting efficiency of the silicon rod 1, speed up the production speed of photovoltaic modules, reduce the use of consumables during the cutting process, reduce production costs, and achieve cost reduction and efficiency improvement. Figure 2 and Figure 3 , the silicon rod cutting method comprises:

[0065] S1. Stack and fix at least two silicon rods 1 along a first direction on a workbench of a cutting device.

[0066] S2. According to the preset process program of the cutting equipment, the wire mesh 2 of the cutting equipment is controlled to cut the silicon rod 1.

[0067] The first direction is the feed direction of the worktable or wire mesh 2; the cutting wires in the wire mesh 2 move along the second direction and are arranged along the third direction; the first, second, and third directions are perpendicular to each other. The maximum dimension of the silicon rod 1 in the first direction is L1, the maximum dimension of the silicon rod 1 in the second direction is L2, and the dimension of the silicon rod 1 in the third direction is L3. L1 < L2 < L3.

[0068] The maximum dimension L1 of the silicon rod 1 in the first direction is smaller than its maximum dimension L2 in the second direction, which is smaller than its maximum dimension L3 in the third direction. That is, the edge of the silicon rod 1 along the first direction is its shortest side. At least two silicon rods 1 are stacked and fixed on a workbench along the first direction. Cutting is performed using a wire mesh 2 of a cutting device. During cutting, the cutting wires of the wire mesh 2 move along the second direction, ultimately cutting the multiple silicon rods 1 into multiple silicon wafers with a long side dimension L2 and a short side dimension L1. Because the wire mesh 2 can cut at least two silicon rods 1 at a time, the cutting efficiency of the silicon rods 1 is improved, the supply of silicon wafers is increased, the amount of wire mesh 2 required for laying out the silicon rods 1 and the amount of cutting wire required for cutting the silicon rods 1 is reduced, the amount of consumables and cutting fluid used during the cutting process is reduced, and production costs are reduced. Furthermore, the silicon rods 1 are stacked along their shortest sides, with their shortest sides serving as the feed direction. This minimizes the feed distance while cutting at least two silicon rods 1 at a time, ensuring optimal cutting efficiency. In addition, when the cutting wire is cut from one silicon rod 1 and cuts into another silicon rod 1, the movement of the cutting wire is continuous and stable, which can ensure the quality of the cutting surface of the silicon rod 1.

[0069] In some embodiments, the cutting wire is an electroplated diamond wire, which has high strength and cutting force, is not easily broken, and can ensure the cutting quality of the silicon wafer.

[0070] In an embodiment of the present invention, the workbench is a feeding table, which feeds along a first direction and is combined with the movement of the wire mesh 2 to achieve cutting of the silicon rods 1 .

[0071] The feeding direction of the worktable is opposite to the moving direction of the wire mesh 2. Figure 2 In some embodiments, the workbench can drive the silicon rod 1 to feed downward, that is, move downward, while the wire mesh 2 moves upward to cut the silicon rod 1. In other embodiments, the workbench can drive the silicon rod 1 to feed upward, that is, move upward, while the wire mesh 2 moves downward to cut the silicon rod 1.

[0072] The cutting equipment used in this embodiment is a multi-wire saw. The worktable is driven by a first drive mechanism, while the wire web 2 is driven by a second drive mechanism. Alternatively, the first and second drive mechanisms can be pneumatic cylinders, oil cylinders, linear modules, electric push rods, or other drive mechanisms, as long as they can drive the worktable and wire web 2 in the first direction. The structure of the multi-wire saw is a mature existing technology and will not be further described here.

[0073] In an embodiment of the present invention, step S2 includes:

[0074] The feed speed of the workbench along the first direction is obtained according to a preset process program.

[0075] Control the table movement according to the feed rate.

[0076] The feed rate ranges from 100 μm / min to 2500 μm / min.

[0077] The feed speed for each step is pre-set in the preset process program, and the worktable moves according to the feed speed set in each step. Limiting the feed speed to a range of 100μm / min to 2500μm / min allows for a wide adjustment range of the feed speed. High feed speeds can be used in some steps to increase cutting speeds, while low feed speeds can be used in other steps to ensure wafer cutting quality.

[0078] In an embodiment of the present invention, step S2 further includes:

[0079] Get the linear speed of the cutting line according to the preset process program.

[0080] Control the cutting wire movement according to the wire speed.

[0081] The linear speed ranges from 1300 m / min to 2400 m / min.

[0082] The linear speed of the cutting line is pre-set for each step in the preset process program, and the cutting line moves at the speed set in each step. Limiting the linear speed of the cutting line to a range of 1300m / min to 2400m / min allows for a wide adjustment range of the linear speed, allowing for high-speed cutting in certain steps, improving cutting speed, while allowing for low-speed cutting in other steps to ensure wafer cutting quality. Furthermore, the minimum linear speed limit of 1300m / min ensures a fast overall cutting speed, while the maximum linear speed limit of 2400m / min prevents problems such as wire breakage and poor wafer cutting quality caused by excessive linear speed.

[0083] In an embodiment of the present invention, step S2 further includes:

[0084] Obtain the wire feed length and wire return length of the cutting wire according to the preset process program.

[0085] The cutting line movement is controlled according to the wire feeding length and the wire returning length.

[0086] The length of the feed line ranges from 800m to 1100m, and the length of the return line ranges from 600m to 2200m.

[0087] The wire feeding length and wire return length of the cutting wire in each step are pre-set in the preset process program, and the cutting wire moves and cuts according to the wire feeding length and wire return length set in each step.

[0088] Specifically, the cutting direction of the cutting line is alternating between cutting in the wire feed direction and cutting in the wire return direction, wherein the wire feed direction and the wire return direction are opposite cutting directions, wherein the cutting line moves in the wire feed direction as the wire feed direction, and moves in the wire return direction as the wire return direction, thereby enabling the cutting line's movement in the preset process program to alternate between wire feeding and wire return. The wire feed length is the length of the cutting line after the cutting line has completed moving in the wire feed direction; the wire return length is the length of the cutting line after the cutting line has completed moving in the wire return direction. The wire feed direction and the wire return direction are both along the second direction, and the wire feed direction and the wire return direction are opposite.

[0089] Limiting the feed wire length to 800m to 1100m and the return wire length to 600m to 2200m allows for rapid replenishment of wire worn by high-speed cutting. Multiple cutting wires in wire mesh 2 are spaced along a third direction, and the spacing between adjacent cutting wires in wire mesh 2 is the thickness of the silicon wafer being cut. Limiting the feed wire length and return wire length in this embodiment maintains the spacing between adjacent cutting wires in wire mesh 2 within a certain range. For example, if the thickness of the silicon wafer to be processed is 130μm, the spacing between adjacent cutting wires in wire mesh 2 should be 130μm. Limiting the feed wire length to 800m to 1100m and the return wire length to 600m to 2200m maintains the spacing between adjacent cutting wires in wire mesh 2 within 130μm ± 10μm, ensuring acceptable silicon wafer thickness. This also ensures that the cutting wires in wire mesh 2 maintain appropriate tension, improving cutting quality, reducing cutting wire vibration, and enhancing the surface finish of the silicon wafer. Limiting the wire feeding length to 1100m can prevent over-replenishment of cutting wire and reduce cutting wire consumption.

[0090] In an embodiment of the present invention, the cutting device includes two first wire pulleys spaced apart from each other; the cutting wire is wound around the two first wire pulleys, forming a wire web 2 between the two first wire pulleys. In step S2, the tension of the wire web 2 on the two first wire pulleys is controlled to be between 3.1N and 3.6N to maintain the tension of the cutting wire within an appropriate range, avoiding insufficient cutting force due to insufficient tension or wire breakage due to excessive tension.

[0091] The tension value of the cutting line for each step is pre-set in the preset process program in step S2. The cutting equipment includes a tension adjustment device. During the cutting process, the tension adjustment device is controlled according to the tension value set in each step to adjust the cutting line to an appropriate tension value.

[0092] In some optional embodiments, the cutting device further includes a second wire pulley. In some feasible solutions, a single second wire pulley is provided and positioned below the two first wire pulleys, with the three forming a triangle and driving the cutting line when driven by a motor. In other feasible solutions, two second wire pulleys may be provided, spaced apart and positioned below the two first wire pulleys, with the center-to-center distance between the two second wire pulleys being greater than the center-to-center distance between the two first wire pulleys. The cutting line is wound around the two first wire pulleys and the two second wire pulleys, and the two second wire pulleys drive the cutting line when driven by the motor.

[0093] In an embodiment of the present invention, the preset process program in step S2 also includes settings for the cutting fluid flow rate and cutting fluid temperature in the cutting equipment. Exemplarily, the cutting fluid flow rate ranges from 220L / min to 280L / min, such as 220L / min, 240L / min, 260L / min, 280L / min, and the like. Exemplarily, the cutting fluid temperature ranges from 16°C to 22°C, such as 16°C, 18°C, 20°C, 22°C, 24°C, and the like. Throughout the cutting process, the cutting fluid flow rate can remain unchanged, and the cutting fluid temperature can remain unchanged.

[0094] In some exemplary embodiments, the dimensions of a single silicon rod 1 are 182.2 mm x 105 mm, i.e., L2 is 182.2 mm and L1 is 105 mm. Taking the example of cutting two silicon rods 1 at a time, the preset process sequence for cutting silicon rods 1 into silicon wafers using the silicon rod cutting method provided in an embodiment of the present invention is shown in the following table.

[0095] Table 1: Preset process procedures

[0096]

[0097]

[0098] The preset process program consists of 17 steps for cutting two silicon ingots (1) measuring 182.2 mm x 105 mm at a time. The starting feed position is -1 mm, and the final feed position is 219 mm, ensuring that both ingots (1) can be cut within the entire feed stroke. The left and right tensions in Table 1 represent the tensions of the wire web (2) on the two primary wire pulleys, respectively.

[0099] The side of the silicon rod 1 facing away from the workbench is defined as the cutting surface 11, and the side of the silicon rod 2 facing the workbench is defined as the cutting surface 12. Figure 3 The silicon rod 1 shown has a workbench (not shown) located above it. The lower surface of the silicon rod 1 is a cutting surface 11 , and the upper surface is a cutting surface 12 .

[0100] In some embodiments, the preset process program includes a first process flow and a second process flow for each silicon rod 1. In step S2:

[0101] The current silicon rod 1 is cut using the first process flow and the second process flow in sequence. When the second process flow is executed, the cutting line passes through the cut-out surface 12 of the current silicon rod 1. That is, the cut-out surface 12 of the silicon rod 1 is cut when the second process flow is executed, and after the cutting line passes through the cut-out surface 12, the silicon rod 1 is cut into a plurality of silicon wafers. Specifically, the feed speed of the workbench in the second process flow is in the range of 100 μm / min to 500 μm / min, and is less than the feed speed of the workbench in the first process flow. The linear speed of the cutting line in the second process flow is in the range of 1100 m / min to 1500 m / min, and is less than the linear speed of the cutting line in the first process flow.

[0102] During the process from the first process flow to the second process flow, the feed speed of the workbench is reduced to 100μm / min~500μm / min, and the linear speed of the cutting line is reduced to 1100m / min~1500m / min. That is, the second process flow adopts low feed speed and low linear speed to cut the silicon wafer exit surface, which can reduce the damage of the cutting line to the edge of the silicon wafer exit surface, reduce edge chipping, and reduce bright edge.

[0103] Exemplarily, the second process flow includes two steps, which are defined as a first step and a second step respectively. The feed speed and line speed of the first step and the second step are reduced successively to ensure good quality of the silicon wafer cutting surface.

[0104] See also Figure 2 Combined with the process flow chart for cutting two silicon ingots 1 (Table 1), the feed position between -1mm and 105mm corresponds to the first process flow for the lower silicon ingot 1. Between 106mm and 117mm, the feed position corresponds to the second process flow for the lower silicon ingot 1. The feed speed is reduced to 100μm / min to 500μm / min, and the cutting line speed is reduced to 1100m / min to 1500m / min to reduce the strain on the wafer exit surface caused by the wire mesh 2. Specifically, the first step in the second process flow is step 7 in Table 1, and the second step is step 8 in Table 1. The first step and the second step correspond to two feed positions, namely, feed position 111 mm and feed position 114 mm, respectively. At the feed position 111 mm, the feed speed is 300 μm / min and the linear speed is 1320 m / min. At the feed position 114 mm, the feed speed is 100 μm / min and the linear speed is 1320 m / min.

[0105] For the upper silicon rod 1, the first process flow corresponds to a feed position of 118mm to 214mm, and the second process flow corresponds to a feed position of 215mm to 219mm. In the second process flow, the feed speed is reduced to 100μm / min to 500μm / min, and the linear speed of the cutting wire is reduced to 1100m / min to 1500m / min to reduce the tension and collapse of the silicon wafer exit surface by the wire mesh 2. Specifically, for the upper silicon rod 1, the first step in the second process flow is step 16 in Table 1, and the second step is step 17 in Table 1. The first and second steps correspond to the feed position of 216mm and the feed position of 219mm, respectively. At the feed position of 216mm, the feed speed is 300μm / min and the linear speed is 1320m / min. At the feed position of 219mm, the feed speed is 100μm / min and the linear speed is 1320m / min.

[0106] In an embodiment of the present invention, step S2 specifically includes:

[0107] Get the feed position of the workbench.

[0108] Before the worktable reaches the target feed position, a new cutting line is used for cutting, wherein the new cutting line is an unused cutting line.

[0109] After the worktable reaches the target feed position, the old cutting line is used for cutting, wherein the old cutting line is the cutting line used before reaching the target feed position.

[0110] Before the table reaches the target feed position, a new cutting wire is used for cutting. The new cutting wire is sharp and has strong cutting force, which can prevent the cutting wire from vibrating and affecting the silicon wafer surface quality. After the table reaches the target feed position, an old cutting wire that has only been used once is used for cutting. The cutting force of the cutting wire is still strong, which can avoid affecting the silicon wafer surface quality.

[0111] The distance between the target feed position and the initial feed position accounts for 90% to 97% of the total feed distance. Among them, the total feed distance is the distance between the final feed position and the initial feed position. That is to say, at the end of the cutting, when the last silicon rod 1 is about to be cut out, the old cutting line that has been used only once is used for cutting. The cutting force of the old cutting line is still strong, which can avoid the phenomenon of the cutting line shaking and breaking the silicon wafer cutting surface due to insufficient cutting force. Before the target feed position, the new cutting line is used for cutting. When cutting all silicon rods 1 before the last silicon rod 1, the new cutting line is used for cutting. The new cutting line has a strong cutting force, which can avoid the cutting line shaking and breaking the silicon wafer cutting surface.

[0112] Specifically, in the process table for cutting two silicon rods 1, the target feed position is 208 mm. Figure 2In the middle position, the silicon rod 1 below is cut with a new cutting wire to ensure the cutting force of the cutting wire on the silicon wafer cutting surface, so that the silicon rod 1 below has no broken edges or bright edges, and the cutting quality is excellent.

[0113] The cutting device also includes a wire feeding wheel and a wire taking-up wheel. The wire feeding wheel and the wire taking-up wheel are rotatably arranged on the body of the cutting device, and the cutting wire can be wound around the wire feeding wheel and the wire taking-up wheel.

[0114] In some embodiments, while the workbench is reaching the target feed position, the wire feed wheel of the cutting device is controlled to deliver a new cutting wire of length M1 to the wire take-up wheel. After the workbench reaches the target feed position, the wire take-up wheel is controlled to deliver an old cutting wire of length M2 to the wire feed wheel. When the workbench reaches the target feed position, an old cutting wire of length M3 is wound around the wire take-up wheel, where M1>M3>M2. That is, the length M3 of the old cutting wire wound around the wire take-up wheel should be greater than the length M2 of the old cutting wire being returned, ensuring that the process of delivering the old cutting wire from the wire take-up wheel to the wire feed wheel is continuous and avoiding interruptions in cutting.

[0115] Furthermore, when the workbench reaches the target feeding position, a cutting wire of length M4 is wound on several wheels for winding the wire web 2, where M1 = M3 + M4.

[0116] Specifically, in this embodiment, taking the cutting of two silicon rods 1 measuring 182.2 mm x 105 mm as an example, while the worktable reaches the target feed position, the wire feed reel is controlled to deliver a new cutting wire, M1 = 20.9 km in length, to the take-up reel. At the target feed position, several reels (including the aforementioned first and second wire reels) of the winding wire mesh 2 are wound with a cutting wire, M4 = 7 km in length, and the take-up reel is wound with a cutting wire, M3 = 13.9 km in length. During the cutting process after the worktable reaches the target feed position, the take-up reel is controlled to deliver an old cutting wire, M2 = 8.3 km in length, to the wire feed reel.

[0117] In the embodiment of the present invention, referring to the process table for cutting two silicon ingots 1, during the process of the worktable reaching the target feed position, that is, during the process from the feed position -1 mm to the feed position 208 mm, the feed wire length is greater than the return wire length. During the cutting process after the worktable reaches the target feed position, that is, during the process from the feed position 208 mm to the feed position 219 mm, the return wire length is greater than the feed wire length.

[0118] In an embodiment of the present invention, step S1: stacking and fixing at least two silicon rods 1 along a first direction on a workbench of a cutting device, specifically includes:

[0119] The backing plate 4 is fixed on the carrier 5 .

[0120] At least two silicon rods 1 are bonded sequentially along a first direction on a side of the backing plate 4 facing away from the carrier 5 .

[0121] The carrier 5 is turned upside down and fixed on a workbench so that the silicon rods 1 are located below the workbench.

[0122] The multiple silicon rods 1 on the carrier 5 use only one backing plate 4, specifically a plastic plate. If the multiple silicon rods 1 were cut individually, an equal number of plastic plates would be required. However, in this application, at least two silicon rods 1 are stacked together for cutting, so only one plastic plate is required for the multiple silicon rods 1, which can reduce the amount of plastic plates used and reduce costs.

[0123] For example, in some embodiments, two silicon rods 1 are sequentially bonded to the side of the plastic plate facing away from the carrier 5 , and only one plastic plate is needed to cut the two silicon rods 1 .

[0124] Silicon rods 1 are bonded to the plastic plate with adhesive 3, and silicon rods 1 are bonded to each other with adhesive 3. When stacking two silicon rods 1, the first silicon rod 1 is bonded to the plastic plate on carrier 5, and the second silicon rod 1 is bonded to the first silicon rod 1. Then, carrier 5 is inverted and fixed on a workbench, and the two silicon rods 1 are cut according to a preset process. The plastic plate and carrier 5 can also be bonded with adhesive 3.

[0125] In some embodiments, the adhesive 3 is a two-component epoxy resin AB glue. The weight ratio of component A to component B in the epoxy resin AB glue is 1:1. After mixing evenly, apply it to the bonding surface. The dosage is 0.005g to 0.006g per square centimeter. After the silicon rod 1 is bonded to the plastic plate, it can be left to stand for 4 to 6 hours before cutting.

[0126] The silicon rod cutting method provided in the embodiment of the present invention further includes step S3: after the cutting is completed, the carrier 5 is removed from the workbench to complete the silicon wafer cutting.

[0127] Illustratively, the silicon rod cutting method provided in this embodiment is suitable for cutting silicon wafers with a long side size of 160 mm to 220 mm and a short side size of 70 mm to 210 mm.

[0128] In summary, the beneficial effects of the silicon rod cutting method provided in this embodiment are described by taking the cutting of two silicon rods 1 with a specification of 182.2 mm×105 mm as an example.

[0129] 1. Reduce costs.

[0130] (1) Reducing the cost of using electroplated diamond wire. Two silicon rods 1 are stacked together for cutting, reducing the amount of wire mesh 2 used for laying and the amount of diamond wire used for cutting the silicon rods 1. The original annual diamond wire usage per cutting device = 365 days * 10 cuts * (12 + 7) kilometers * 2 = 138,700 kilometers; using the cutting method provided by the embodiment of the present invention, the annual diamond wire usage per cutting device = 365 days * 10 cuts * 20 kilometers = 73,000 kilometers, thereby reducing the diamond wire usage by 47.4%.

[0131] (2) Reducing the amount of backing plate 4 (plastic plate). Cutting two silicon rods 1 separately requires two plastic plates. In this embodiment, the two silicon rods 1 are stacked together and cut, so only one plastic plate is needed for the two silicon rods 1, thereby reducing the amount of plastic plates used by 50%.

[0132] (3) Reduced cutting fluid usage. Cutting two silicon rods 1 separately requires 2*3=6L of cutting fluid. In this embodiment, cutting two silicon rods 1 stacked together only requires 3L of cutting fluid, thus reducing the amount of cutting fluid usage by 50%.

[0133] 2. Significantly reduce chipping and bright edges on silicon wafers. The new preset process uses a new diamond wire when cutting the second silicon ingot 1, ensuring the cutting force of the diamond wire on the silicon wafer exit surface, so that the second silicon ingot 1 has no chipping or bright edges.

[0134] 3. Improved efficiency. If two silicon ingots 1 are cut separately, the total preparation time, cutting time, and material unloading time is (30 + 80 + 5) * 2 = 230 minutes. In this embodiment, the two silicon ingots 1 are cut together, and the total preparation time, cutting time, and material unloading time is (30 + 156 + 5) = 191 minutes, which is a 16.9% reduction in the total preparation time, cutting time, and material unloading time.

[0135] This embodiment also provides a silicon wafer, which is formed by cutting the silicon rod using the above-mentioned silicon rod cutting method. Since the above-mentioned silicon rod cutting method is used for cutting, the cutting efficiency can be effectively improved while ensuring the cutting quality, thereby increasing the supply of silicon wafers.

[0136] This embodiment also provides a cell, which is made from the silicon wafer described above. Since the cell is made from the silicon wafer described above, the cell quality is guaranteed while the production efficiency of the cell is improved and the production cost of the cell is reduced.

[0137] This embodiment also provides a photovoltaic module comprising the aforementioned cell. Exemplarily, the photovoltaic module includes at least one cell string, which comprises a plurality of electrically connected cells. The cell string can be encapsulated between a front glass panel and a back glass panel to form a photovoltaic module product.

[0138] This embodiment also provides a photovoltaic power generation system, including the photovoltaic components described above, which can accelerate the construction process of the photovoltaic power generation system and significantly reduce the construction cost of the photovoltaic power generation system.

[0139] Photovoltaic power generation systems can be used in photovoltaic power stations, such as ground power stations, rooftop power stations, water-surface power stations, etc., and can also be used in equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it is understandable that the application scenarios of photovoltaic power generation systems are not limited to this, that is, photovoltaic power generation systems can be used in all fields that require solar power generation. Taking the photovoltaic power generation system network as an example, the photovoltaic power generation system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array can be an array combination of multiple battery modules. For example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box, which can combine the current generated by the photovoltaic array. The combined current flows through the inverter to be converted into the AC power required by the mains power grid and then connected to the mains power network to achieve solar power supply.

[0140] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A silicon rod cutting method, characterized in that: include: at least two silicon rods (1) are stacked and fixed on a workbench of a cutting device along a first direction; Controlling the wire mesh (2) of the cutting device to cut the silicon rod (1) according to a preset process program of the cutting device; wherein the first direction is the feeding direction of the workbench or the wire web (2); each cutting line in the wire web (2) moves along the second direction and is arranged along the third direction; the first direction, the second direction and the third direction are perpendicular to each other; The maximum dimension of the silicon rod (1) in the first direction is L1, the maximum dimension of the silicon rod (1) in the second direction is L2, and the dimension of the silicon rod (1) in the third direction is L3; L1<L2<L3.

2. The silicon rod cutting method according to claim 1, characterized in that: Acquiring a feed speed of the workbench along the first direction according to the preset process program; controlling the movement of the worktable according to the feed speed; Wherein, the feed speed ranges from 100 μm / min to 2500 μm / min.

3. The silicon rod cutting method according to claim 2, characterized in that: Obtaining the linear speed of the cutting line according to the preset process program; controlling the movement of the cutting wire according to the wire speed; Wherein, the linear speed ranges from 1300 m / min to 2400 m / min.

4. The silicon rod cutting method according to claim 3, characterized in that: The side of the silicon rod (1) facing away from the workbench is a cutting surface (11), and the side of the silicon rod (2) facing the workbench is a cutting surface (12); The preset process program is provided with a first process flow and a second process flow corresponding to each silicon rod (1); The first process flow and the second process flow are sequentially used to cut the current silicon rod (1); wherein, when the second process flow is performed, the cutting line passes through the cut surface (12) of the current silicon rod (1); The feed speed of the workbench in the second process flow is in the range of 100 μm / min to 500 μm / min, and is less than the feed speed of the workbench in the first process flow; The line speed in the second process flow ranges from 1100 m / min to 1500 m / min, and is less than the line speed in the first process flow.

5. The silicon rod cutting method according to claim 1, wherein: Obtaining the feed length and return length of the cutting line according to the preset process program; Controlling the cutting wire movement according to the wire feeding length and the wire return length; The length of the wire feed ranges from 800m to 1100m.

6. The silicon rod cutting method according to claim 5, characterized in that: The loop length ranges from 600m to 2200m.

7. The silicon rod cutting method according to claim 1, characterized in that: Obtaining a feed position of the workbench; Before the workbench reaches the target feeding position, cutting is performed using a new cutting line; wherein the new cutting line is an unused cutting line; After the workbench reaches the target feeding position, cutting is performed using an old cutting wire, wherein the old cutting wire is a cutting wire that has been used before the workbench reaches the target feeding position.

8. The silicon rod cutting method according to claim 7, characterized in that: When the workbench reaches the target feeding position, controlling the wire feeding wheel of the cutting device to feed the new cutting wire of length M1 to the wire taking-up wheel; After the workbench reaches the target feeding position, controlling the wire take-up wheel to convey the old cutting wire of length M2 to the wire feeding wheel; Wherein, when the workbench reaches the target feeding position, the old cutting wire of length M3 is wound around the take-up wheel, and M1>M3>M2.

9. The silicon rod cutting method according to claim 7, characterized in that: The distance between the target feeding position and the initial feeding position accounts for 90% to 97% of the total feeding distance; The total feeding distance is the distance between the final feeding position and the initial feeding position.

10. The silicon rod cutting method according to any one of claims 1 to 9, characterized in that: The cutting device comprises two first wire wheels arranged at intervals; the cutting wire is wound around the two first wire wheels, and the wire web (2) is formed between the two first wire wheels; The tension of the wire web (2) on the two first wire wheels is controlled to be 3.1N to 3.6N.

11. The silicon rod cutting method according to any one of claims 1 to 9, characterized in that: The method of stacking and fixing at least two silicon rods (1) along a first direction on a workbench of a cutting device comprises: Fixing the backing plate (4) on the carrier (5); At least two silicon rods (1) are sequentially bonded along the first direction on a side of the backing plate (4) facing away from the carrier (5); The carrier (5) is inverted and fixed on the workbench so that the silicon rod (1) is located below the workbench.

12. A silicon wafer, characterized in that The silicon rod is cut and formed by the silicon rod cutting method according to any one of claims 1 to 11.

13. A battery cell, characterized in that: It is prepared using the silicon wafer as claimed in claim 12.

14. A photovoltaic module, characterized in that The battery cell according to claim 13 is included.

15. A photovoltaic power generation system, characterized in that: Comprising the photovoltaic module according to claim 14.

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