Silicon rod slotting device, silicon wafer and battery piece

Abstract

The utility model discloses a silicon rod grooving device, a silicon wafer and a battery piece, the silicon rod grooving device is used for forming a longitudinal through groove in a silicon rod, the silicon rod grooving device comprises an ultrasonic machining assembly and a grooving cutter connected with the ultrasonic machining assembly, and the ultrasonic machining assembly is used for driving the grooving cutter to make ultrasonic vibration. The grooving cutter connected with the ultrasonic machining assembly is adopted for grooving, compared with a traditional grinding grooving mode, the longitudinal through groove formed in the silicon rod is neat in groove shape and small in edge breakage and burr, the surface quality of the longitudinal through groove is improved, subsurface damage of the longitudinal through groove is reduced, and the service life of the longitudinal through groove is prolonged. Therefore, the fragment rate of the grooved silicon wafer in subsequent working sections such as degumming, cleaning, sorting and the like is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of silicon rod processing, in particular to a silicon rod slotting device, a silicon slice and a battery slice. Background Art

[0002] Solar cells are made of silicon wafers through processes such as surface texturing and diffusion. Silicon wafers are obtained by slicing silicon rods. Multiple solar cells are connected by welding ribbons to form a battery string. When multiple solar cells are connected by welding ribbons, a certain gap is usually required. However, the larger the gap between two adjacent solar cells, the smaller the power generation per unit area of ​​the solar cell will be.

[0003] Therefore, before slicing the silicon rod, it is usually necessary to process the through grooves for connecting the welding ribbons. When the battery cell with the through grooves is connected to the welding ribbons, the welding ribbons can pass through the through grooves to avoid the gap formed by the thickness of the welding ribbons at the splicing position of two adjacent battery cells. The smaller the gap, the higher the battery utilization rate can be, and the less likely the battery cells will crack or break during lamination.

[0004] At present, in the prior art, a silicon rod is usually slotted by a grinding device, wherein the grinding device comprises a grinding wheel and a rotating motor for driving the grinding wheel to rotate.

[0005] However, since the silicon rod is a hard and brittle material, it is prone to wear and surface damage during the grinding process, which can lead to problems such as burrs on the grooves on the silicon rod, broken edges and irregular bottom groove shapes. Poor grooving quality and irregular bottom groove shapes can lead to stress concentration, which in turn leads to a high fragmentation rate of silicon wafers obtained by slicing the grooved silicon rods during subsequent processes such as degumming, cleaning and sorting. Utility Model Content

[0006] The utility model provides a silicon rod grooving device, a silicon wafer and a battery cell, aiming to at least solve the technical problem that the bottom groove shape of the groove opened on the silicon rod by the conventional grinding device in the prior art is not neat, which leads to a high fragmentation rate of the silicon wafer obtained by slicing the silicon rod after the groove in the subsequent processes such as degumming, cleaning and sorting.

[0007] In a first aspect, an embodiment of the utility model provides a silicon rod grooving device for opening a longitudinal through groove on a silicon rod, wherein the silicon rod grooving device comprises an ultrasonic machining component and a grooving tool connected to the ultrasonic machining component, wherein the ultrasonic machining component is used to drive the grooving tool to perform ultrasonic vibration.

[0008] Optionally, when the cross-section of the silicon rod is square, the silicon rod has four side surfaces, and the silicon rod grooving device is used to provide a plurality of the longitudinal through grooves at intervals on at least one of the side surfaces of the silicon rod.

[0009] Optionally, the slotting tool comprises a grinding wheel or a milling cutter; the grinding wheel comprises a rough grinding wheel and a fine grinding wheel.

[0010] Optionally, the ultrasonic machining assembly includes a transducer and a horn connected to the transducer, the transducer is electrically connected to an ultrasonic generator via an energy transmission receiver, and the slotting tool is detachably connected to the horn.

[0011] Optionally, a rotating shaft is further included, the slotting tool is connected to the rotating shaft through the ultrasonic machining component, the rotating shaft is connected to a rotating drive member, and the rotating drive member is used to drive the rotating shaft to rotate.

[0012] In a second aspect, an embodiment of the utility model provides a silicon wafer, which is obtained by slicing a silicon rod, wherein the silicon rod has a longitudinal through groove formed by processing using any of the silicon rod grooving devices described above, and the silicon wafer has a longitudinal through groove.

[0013] Optionally, the longitudinal through groove is a welding strip passing through groove, and a plurality of the welding strip passing through grooves are arranged at intervals on at least one side edge of the silicon wafer.

[0014] Optionally, the depth of the through groove through which the welding strip passes is 0.1 mm-1 mm;

[0015] The width of the slot through which the welding strip passes is 0.5 mm to 2 mm.

[0016] Optionally, the shape of the welding strip passage slot is any one of an arc, a rectangle, a trapezoid, and a triangle.

[0017] In a third aspect, an embodiment of the utility model provides a battery cell, comprising any silicon wafer described above.

[0018] In the embodiment of the utility model, a slotting tool connected to an ultrasonic machining component is used for slotting. Compared with the traditional grinding slotting method, the longitudinal through-grooves opened on the silicon rod have neat groove shapes and small edge collapse burrs, which improves the surface quality and surface finish of the longitudinal through-grooves, reduces the sub-surface damage of the longitudinal through-grooves, and thus reduces the fragmentation rate of the silicon wafers after slotting in subsequent processes such as degumming, cleaning and sorting. In addition, when the slotting tool is slotting, the ultrasonic machining component provides ultrasonic vibration assistance for the slotting tool to slot, which improves the processing efficiency and shortens the processing cycle. In addition, the slotting tool uses ultrasonic vibration cutting to slot, which also reduces the cutting force, reduces the cutting heat, reduces the wear and edge collapse burrs of the slotting tool, and facilitates the discharge of the generated chips.

[0019] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the exploded structure of an ultrasonic machining component in a silicon rod slotting device provided in an embodiment of the utility model;

[0021] Figure 2 A schematic diagram of the structure of a grinding wheel in a silicon rod grooving device provided in an embodiment of the utility model;

[0022] Figure 3 A schematic diagram of the structure of an ultrasonic generator and a numerical control system in a silicon rod slotting device provided in an embodiment of the utility model;

[0023] Figure 4 A schematic diagram of the three-dimensional structure of a silicon rod processed by a silicon rod grooving device;

[0024] Figure 5 A flow chart of the steps of making grooves on a silicon rod by a silicon rod groove making device;

[0025] Figure 6 A schematic diagram of the structure of a silicon wafer provided in an embodiment of the utility model;

[0026] Figure 7 A schematic diagram of the arrangement of multiple battery cells provided in an embodiment of the utility model.

[0027] Reference numerals:

[0028] 1-ultrasonic machining component, 11-transducer, 12-amplifier, 13-tool handle body, 14-energy receiver, 2-grinding wheel, 3-ultrasonic generator, 4-CNC system, 5-silicon rod, 51-side surface, 52-longitudinal groove, 6-silicon wafer, 7-welding strip passing groove, 8-battery cell. DETAILED DESCRIPTION

[0029] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0030] The photovoltaic module includes a plurality of battery strings, which include a plurality of battery strings, and the battery string is composed of a plurality of battery cells connected in an electrically connected manner. The battery cell includes a silicon wafer and a grid line arranged on the silicon wafer. The silicon wafer is obtained by slicing a silicon rod.

[0031] At present, it is gradually becoming a trend to cancel the spacing between cells in photovoltaic modules and achieve zero spacing or negative spacing between cells. In existing photovoltaic modules, when multiple cells are interconnected, one end of the welding tape is connected to the front of a cell, and the other end of the welding tape is connected to the back of the adjacent cell. After the two cells are connected, there is a gap between the two cells due to the thickness of the welding tape. During the lamination process, due to the gap between the two cells, the pressure in the laminator will cause the hidden crack rate and the broken rate of the cells at the splicing point to increase. In order to solve the above problems, a through groove is usually opened on the silicon rod, and the silicon wafer obtained after the silicon rod is sliced ​​has the through groove. For this reason, when the cell including the cut silicon wafer is interconnected with other cells, the welding tape passes through the through groove, and its two ends are respectively connected to the front and back of the adjacent cell. Since the welding tape is located in the through groove, there is no gap at the splicing of the two cells, thus solving the problem of hidden cracks or breakage of the cells in the lamination process.

[0032] First, refer to Figure 1 and Figure 4 The embodiment of the utility model discloses a silicon rod slotting device for opening a longitudinal through groove 52 on a silicon rod 5. The silicon rod slotting device comprises an ultrasonic machining component 1 and a slotting tool connected to the ultrasonic machining component 1. The ultrasonic machining component 1 is used to drive the slotting tool to perform ultrasonic vibration.

[0033] The production process of battery cells also involves the slicing of battery cells. When slicing battery cells, they are usually first sliced ​​by a laser scriber, and then the battery cells are split into multiple slices according to the scratches. The laser scriber uses a high-energy laser beam to irradiate the surface of the battery cell, causing the irradiated area to partially melt and vaporize, thereby achieving the purpose of slicing. When slicing with a laser scriber, laser slicing can be performed directly, or the silicon rod can be grooved first, and the grooved silicon wafers can be obtained after slicing, and then the slicing can be positioned according to the groove position to improve the positioning accuracy. The longitudinal through groove 52 opened by the silicon rod grooving device on the silicon rod 5 can be used as a through groove for positioning when the laser scriber is slicing.

[0034] The longitudinal groove 52 penetrates the silicon rod along the length direction of the silicon rod. After the longitudinal groove 52 is formed on the silicon rod 5, the silicon wafer 6 obtained by slicing also has the longitudinal groove 52. The longitudinal groove 52 on the silicon wafer 6 can be a welding strip passing groove 7. The welding strip passing groove 7 is used for the welding strip to pass through. Figure 7The welding strip passing groove 7 is located at least on one side edge of the battery cell 8 for splicing, and the side edge for splicing refers to the side edge of the battery cell 8 at the splicing position when the battery cell 8 is interconnected with other battery cells.

[0035] When the battery cell 8 is interconnected with other battery cells, the welding ribbon passes through the welding ribbon through groove 7, and its two ends are respectively connected to the front and back of the adjacent battery cell. Since the welding ribbon is located in the welding ribbon through groove 7, there is no gap at the splicing position of the two battery cells, thus solving the problem of hidden cracks or breakage of the battery cells during the lamination process. In addition, the laser scribing machine can be positioned according to the position of the welding ribbon through groove 7 when scribing, which improves the scribing positioning accuracy and does not require additional positioning grooves.

[0036] The ultrasonic machining component 1 is a machining component based on ultrasonic machining technology. Ultrasonic machining technology is a process technology that uses ultrasonic vibration energy to achieve precise removal of difficult-to-machine materials. This technology focuses the ultrasonic vibration energy on the working area of ​​the tool through the propagation and transformation of a series of structures, thereby forming an impact removal effect on the cut material, thereby improving the machinability of many difficult-to-machine materials.

[0037] Ultrasonic vibration refers to vibration with a frequency in the range of 15KHz-30KHz. The ultrasonic vibration direction of the ultrasonic machining component 1 driving the slotting tool can be in the longitudinal direction, which is perpendicular to the height direction of the ultrasonic machining component 1. The height direction of the ultrasonic machining component 1 can be referred to as Figure 1 The direction indicated by the arrow A. The amplitude of the grooving tool vibration can be 10 microns to 50 microns.

[0038] Grooving is performed using a grooving tool connected to the ultrasonic machining component 1. Compared with the traditional grinding grooving method, the longitudinal through grooves opened on the silicon rod have neat groove shapes and small edge collapse and burrs, which improves the surface quality and surface finish of the longitudinal through grooves and reduces the sub-surface damage of the longitudinal through grooves, thereby reducing the fragmentation rate of the silicon wafers after the grooving during subsequent processes such as degumming, cleaning and sorting.

[0039] Due to the high hardness of silicon rods, the traditional grinding slotting method has low slotting efficiency and a long processing cycle. In the embodiment of the utility model, when the slotting tool is slotting, the ultrasonic machining component provides ultrasonic vibration to the slotting tool to assist in slotting, thereby improving the processing efficiency and shortening the processing cycle. In addition, the slotting tool uses ultrasonic vibration cutting to slot, which also reduces the cutting force, reduces the cutting heat, reduces the wear and chipping burrs of the slotting tool, and facilitates the discharge of the generated chips.

[0040] If the laser grooving method is used to groove the silicon rod, the temperature of the grooved area is relatively high, such as the temperature can be as high as 600°C or above, and the grooved area is greatly affected by thermal stress, which leads to hidden cracks in the silicon wafer after the groove, and further increases the fragmentation rate of the battery cell including the silicon wafer. In the embodiment of the utility model, the grooving tool uses ultrasonic vibration cutting to perform grooving, which can reduce cutting heat, thereby making the temperature of the grooved area lower, thereby reducing the thermal stress of the grooved area, and avoiding hidden cracks in the silicon wafer after the groove.

[0041] When the cross-section of the silicon rod 5 is rectangular, the silicon rod 5 has four side surfaces 51, and the silicon rod grooving device can perform grooving on at least one side surface 51 of the silicon rod 5, such as one side surface 51, two opposite side surfaces 51, three side surfaces 51, or all four side surfaces 51.

[0042] When the cross-section of the silicon rod 5 is in a square shape, the silicon rod 5 has four side surfaces 51 , and the silicon rod slotting device is used to provide a plurality of longitudinal through slots 52 at intervals on at least one side surface 51 of the silicon rod 5 .

[0043] Specifically, a plurality of longitudinal through grooves 52 may be provided on one side surface 51 of the silicon rod 5 , or on two opposite side surfaces 51 , or on three side surfaces 51 , or on all four side surfaces 51 . Figure 4 The two opposite side surfaces 51 of the silicon rod 5 shown in the figure are both provided with a plurality of longitudinal through grooves 52. When the plurality of longitudinal through grooves 52 are provided at intervals on the plurality of side surfaces 51 of the silicon rod 5, the plurality of longitudinal through grooves 52 are arranged at intervals on the plurality of side edges of the silicon slice 6 obtained by slicing the silicon rod 5, so as to ensure that each cell slice including the silicon slice 6 has the longitudinal through groove 52 after being sliced.

[0044] Reference Figure 2 The slotting tool includes a grinding wheel 2 or a milling cutter; the grinding wheel 2 includes a rough grinding wheel and a fine grinding wheel.

[0045] Specifically, the grinding wheel 2 can be a diamond grinding wheel, and the milling cutter can be a milling cutter including a diamond drill bit. Both the rough grinding wheel and the fine grinding wheel are diamond grinding wheels. The rough grinding wheel includes a first grinding wheel base and a first abrasive layer, and the first abrasive layer contains coarse-grained diamonds. The fine grinding wheel includes a second grinding wheel base and a second abrasive layer, and the second abrasive layer contains fine-grained diamonds. When the grinding wheel 2 is used for grooving, the rough grinding wheel can be used for rough grinding first, and then the fine grinding wheel can be used for fine grinding to ensure the surface quality and surface finish of the through grooves opened.

[0046] Reference Figure 1 and Figure 3 The ultrasonic machining assembly 1 includes a transducer 11 and an horn 12 connected to the transducer 11 . The transducer 11 is electrically connected to the ultrasonic generator 3 via an energy transmission receiver 14 . The slotting tool is detachably connected to the horn 12 .

[0047] Specifically, the ultrasonic generator 3 is also connected to the numerical control system 4 through the ultrasonic controller, and the numerical control system 4 adjusts the working parameters of the ultrasonic generator 3, such as output power and working frequency, through the ultrasonic controller. The transducer 11 can be a nickel sheet magnetostrictive transducer. The ultrasonic generator 3 provides an ultrasonic electrical signal to the transducer 11, and the transducer 11 converts the electrical energy into mechanical energy of ultrasonic vibration. The ultrasonic vibration is output to the horn 12, and after the amplitude is amplified by the horn 12, the mechanical vibration is transmitted to the slotting tool. Through the setting of the horn 12, the amplitude of the vibration can be amplified so that the amplitude of the vibration of the slotting tool meets the requirements.

[0048] The ultrasonic machining assembly 1 also includes a handle body 13, on which the transducer 11 and the horn 12 are both arranged. The ultrasonic machining assembly 1 may also include an energy transmission receiver 14 electrically connected to the transducer 11. The ultrasonic generator 3 is electrically connected to a transmitter, and the transmitter is electrically connected to the energy transmission receiver 14 by wireless connection. The ultrasonic electrical signal provided by the ultrasonic generator 3 is transmitted to the transducer 11 through the transmitter and the energy transmission receiver 14.

[0049] The silicon rod slotting device provided by the embodiment of the utility model also includes a rotating shaft, and the slotting tool is connected to the rotating shaft through the ultrasonic machining component 1, and the rotating shaft is connected to a rotating drive member, and the rotating drive member is used to drive the rotating shaft to rotate. The rotating drive member can be a rotating motor or the like. During operation, the rotating drive member drives the rotating shaft to rotate, and when the rotating shaft rotates, it will drive the ultrasonic machining component 1 to rotate, thereby driving the slotting tool to rotate through the ultrasonic machining component 1. Specifically, the tool handle body 13 in the ultrasonic machining component 1 is connected to the rotating shaft. When the slotting tool is slotting on the silicon rod, the rotating shaft drives the slotting tool to rotate, and at the same time, the ultrasonic machining component 1 drives the slotting tool to perform ultrasonic vibration. The rotation of the slotting tool serves as the main motion, and the ultrasonic vibration assists the processing.

[0050] The silicon rod slotting device further comprises a silicon rod feeding mechanism and a silicon rod clamping mechanism, wherein the silicon rod clamping mechanism is used to clamp the silicon rod, and the silicon rod feeding mechanism is used to drive the silicon rod to do feeding movement, and the feeding movement direction is consistent with the length direction of the silicon rod. When slotting the silicon rod, the ultrasonic machining component 1 and the slotting tool are located on the left or right side of the silicon rod.

[0051] The silicon rod slotting device also includes a tool feeding and moving mechanism, wherein the rotating shaft and the rotating driving member are both installed in the base, and the tool feeding and moving mechanism is connected to the base, and is used to drive the base to do feeding and moving, so that the rotating shaft installed in the base and the ultrasonic machining component 1 connected to the rotating shaft and the slotting tool are fed and moved. The tool feeding and moving mechanism may include a driving motor and a ball screw assembly connected to the driving motor, the ball screw assembly includes a screw and a ball nut, the driving motor is connected to the screw, and the ball nut is connected to the base. The driving motor is used to drive the screw to rotate, and when the screw rotates, the ball nut moves.

[0052] Reference Figure 5 The specific steps of slotting the silicon rod by the silicon rod slotting device are as follows:

[0053] S1, select a slotting tool. The slotting tool includes a grinding wheel or a milling cutter. The grinding wheel includes a rough grinding wheel and a fine grinding wheel. The diameter of the rough grinding wheel is 50mm-150mm, and the diameter of the fine grinding wheel is 50mm-150mm.

[0054] S2, when the grinding wheel is selected as the slotting tool, the rough grinding wheel is first installed on the ultrasonic machining assembly.

[0055] S3, setting ultrasonic machining parameters and rough grinding machining parameters, and performing rough grinding and grooving.

[0056] The ultrasonic machining parameters include the amplitude of tool vibration, the output power and the operating frequency of the ultrasonic generator 3. The output power of the ultrasonic generator 3 can be 250W-1000W, the operating frequency of the ultrasonic generator 3 can be 15KHz-30KHz, and the amplitude of tool vibration can be 10 microns-50 microns. The rough grinding machining parameters include rough grinding linear speed, rough grinding single-knife feed, rough grinding tool speed, rough grinding allowance, etc. The rough grinding linear speed can be 20m / s-35m / s, the rough grinding single-knife feed can be 0.1mm-0.5mm, the rough grinding tool speed can be 500mm / min-2000mm / min, and the rough grinding allowance can be 0.1mm. The rotation of the rough grinding wheel is driven by the rotating drive member through the rotating shaft and the ultrasonic machining component 1, and the feed movement of the rough grinding wheel is driven by the tool feed movement mechanism through the base.

[0057] S4, remove the rough grinding wheel and install the fine grinding wheel on the ultrasonic machining assembly.

[0058] S5, setting the fine grinding processing parameters and performing fine grinding and grooving.

[0059] The fine grinding processing parameters include fine grinding linear speed, fine grinding single-knife feed amount, fine grinding tool speed, etc. The fine grinding linear speed can be 20m / s-35m / s, the fine grinding single-knife feed amount can be 0.1mm-0.5mm, and the fine grinding tool speed can be 500mm / min-2000mm / min. The rotation of the fine grinding wheel is driven by the rotating drive member through the rotating shaft and the ultrasonic machining component 1, and the feed movement of the fine grinding wheel is driven by the tool feed movement mechanism through the base.

[0060] The silicon rod slotting device was used for ultrasonic grinding and the existing grinding device was used for traditional grinding slotting. Comparing the two, under the same process and cutting speed conditions, the traditional grinding slotting edge collapse is about 8um, the slot profile is 10um, and the burr rate is about 10% to 30%, while the ultrasonic grinding slotting edge collapse is less than 3um, the slot profile is less than 5um, the burr rate is less than 5%, and the overall slot structure is more neat. In addition, an experimental verification was carried out at the silicon wafer cleaning insert end, and it was found that the silicon wafer cut by the silicon rod processed by the silicon rod slotting device has a low fragmentation rate of about 0.2% to 0.5%.

[0061] Second, refer to Figure 6 The embodiment of the utility model further discloses a silicon wafer, wherein the silicon wafer 6 is obtained by slicing a silicon rod 5, the silicon rod 5 has a longitudinal through groove formed by the silicon rod grooving device, and the silicon wafer 6 has a longitudinal through groove 52.

[0062] The longitudinal through groove 52 is a welding strip through groove 7, and a plurality of welding strip through grooves 7 are arranged at intervals on at least one side edge of the silicon wafer 6. The welding strip through groove 7 is used for the welding strip to pass through, and the welding strip is used to connect the battery cell 8 including the silicon wafer 6. When the battery cell 8 including the silicon wafer 6 is interconnected with other battery cells, there is no gap at the splicing position, thereby solving the problem that the battery cell is prone to cracking or breaking during the lamination process.

[0063] The depth of the welding strip passage groove 7 is 0.1 mm to 1 mm.

[0064] The depth of the welding strip through groove 7 can be referred to Figure 6 The depth H of the welding strip passing through groove 7 can be 0.1 mm, 0.2 mm, 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, etc. When the depth of the welding strip passing through groove 7 is within the above range, the welding strip can pass through the welding strip passing through groove 7 smoothly.

[0065] The width of the slot 7 through which the welding strip passes is 0.5 mm to 2 mm.

[0066] The width of the slot of the welding strip passing through slot 7 can be 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 2 mm, etc. The width of the slot of the welding strip passing through slot 7 is greater than the width of the welding strip. When the width of the slot of the welding strip passing through slot 7 is within the above range, the welding strip can smoothly pass through the welding strip passing through slot 7.

[0067] The shape of the welding strip through slot 7 can be determined according to actual needs, such as the shape of the welding strip through slot 7 can be any one of an arc, a rectangle, a trapezoid, and a triangle. Among them, the arc includes a semicircle. When the shape of the welding strip through slot 7 is the above shape, the structure is simple and easy to process.

[0068] Thirdly, refer to Figure 7 The embodiment of the utility model further discloses a battery cell 8, including the above silicon cell 6. The battery cell 8 can be a whole battery cell, or can include two sub-cells, three sub-cells, four sub-cells, etc. The position of the welding strip through groove 7 can be on the sub-cell. The battery cell 8 is connected to other battery cells through the welding strip, and multiple battery cells 8 are connected through the welding strip to form a battery string.

[0069] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0070] The embodiments of the utility model are described above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the utility model, ordinary technicians in this field can also make many forms without departing from the scope of protection of the utility model and the claims, which all fall within the protection of the utility model.

Claims

1. A silicon rod slotting device, characterized in that: Used for opening longitudinal through grooves on silicon rods, the silicon rod grooving device comprises an ultrasonic machining component and a grooving tool connected to the ultrasonic machining component, and the ultrasonic machining component is used to drive the grooving tool to perform ultrasonic vibration.

2. The silicon rod slotting device according to claim 1, characterized in that: When the cross-section of the silicon rod is in a square shape, the silicon rod has four side surfaces, and the silicon rod slotting device is used to provide a plurality of the longitudinal through slots at intervals on at least one of the side surfaces of the silicon rod.

3. The silicon rod slotting device according to claim 1 or 2, characterized in that: The slotting tool comprises a grinding wheel or a milling cutter; the grinding wheel comprises a rough grinding wheel and a fine grinding wheel.

4. The silicon rod slotting device according to claim 1 or 2, characterized in that: The ultrasonic machining assembly comprises a transducer and a horn connected to the transducer. The transducer is electrically connected to an ultrasonic generator via an energy transmission receiver. The slotting tool is detachably connected to the horn.

5. The silicon rod slotting device according to claim 1 or 2, characterized in that: It also includes a rotating shaft, the slotting tool is connected to the rotating shaft through the ultrasonic machining component, the rotating shaft is connected to a rotating drive member, and the rotating drive member is used to drive the rotating shaft to rotate.

6. A silicon wafer, characterized in that: The silicon wafer is obtained by slicing a silicon rod, the silicon rod has a longitudinal through groove formed by processing the silicon rod grooving device according to any one of claims 1 to 5, and the silicon wafer has the longitudinal through groove.

7. The silicon wafer according to claim 6, characterized in that: The longitudinal through grooves are welding strip passing through grooves, and a plurality of the welding strip passing through grooves are arranged at intervals on at least one side edge of the silicon wafer.

8. The silicon wafer according to claim 7, characterized in that: The depth of the welding strip through groove is 0.1 mm-1 mm; The width of the slot through which the welding strip passes is 0.5 mm to 2 mm.

9. The silicon wafer according to claim 7, characterized in that: The shape of the welding strip passage slot is any one of an arc, a rectangle, a trapezoid, and a triangle.

10. A battery cell, characterized in that: A silicon wafer comprising the silicon wafer as claimed in any one of claims 6 to 9.

Images