Silicon rod cutting method and silicon rod cutting machine
By using the method of cutting along the first straight line and the second straight line in the silicon rod cutting machine, a fully connected cut joint is formed, which solves the problems of edge collapse and gap defects in silicon rod cutting, improves production efficiency, and Repair defects through subsequent polishing.
Patent Information
- Application Number
- CN202310670808.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-07
- Publication Date
- 2024-12-10
AI Technical Summary
During the cutting process of silicon rods, the cut semi-silicon rods are prone to collapse and notch defects, and the prior art requires reducing the feed speed of the cutting line to reduce these defects, resulting in a decrease in production efficiency.
Using a silicon rod cutting method and a cutting machine, the silicon rod is cut along the first straight line and the second straight line through the cutting line to form a first cut joint and a second cut joint, and ensure that the second cut joint and the first cut joint are It is fully connected, and the cutting line is away from the edges of the square silicon rod when it is cut along the second straight line, thereby reducing the occurrence of edges and gaps, and repairing defects through subsequent grinding, without reducing the feed speed of the cutting line.
It effectively reduces the problems of collapse and notch on the edges of the semi-silicon rod, ensures production efficiency, and repairs cutting defects through subsequent processes, improving the quality and efficiency of silicon rod cutting.
Smart Images
Figure CN119099054A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present application relate to the technical field of silicon rod machining, and in particular to a silicon rod cutting method and a silicon rod cutting machine. Background Art
[0002] Photovoltaic cells are made from silicon wafers, which are made from silicon rods. One of the processes in silicon rod processing is to cut the square silicon rod into two half silicon rods. In actual applications, the half silicon rods cut often have edge collapse defects. Summary of the invention
[0003] The embodiments of the present application provide a silicon rod cutting method and a silicon rod cutting machine, and the half silicon rods obtained after cutting are not prone to edge collapse defects.
[0004] In one aspect, a silicon rod cutting method is provided, for cutting a silicon rod using a silicon rod cutting machine, wherein the silicon rod cutting machine comprises a cutting line, and the silicon rod comprises a first side surface and a second side surface opposite to each other, and the method comprises:
[0005] The cutting line cuts a first distance along a first straight line from the first side surface toward the second side surface to form a first slit on the silicon rod;
[0006] The cutting line cuts a second distance along a second straight line from the second side surface toward the first side surface, forming a second slit on the silicon rod;
[0007] The first straight line is located on the first side surface, the second straight line is located on the second side surface, the first straight line and the second straight line are parallel and opposite to each other; the second slit is completely connected with the first slit, so that the silicon rod is divided into a first part and a second part by the first slit and the second slit.
[0008] In some embodiments, the first slit and the second slit are formed by cutting with the same cutting line, and after forming the first slit and before forming the second slit, the method further comprises:
[0009] The cutting line exits the first slit;
[0010] The silicon rod is rotated at a preset angle so that the second side surface faces the cutting line.
[0011] In some embodiments, the silicon rod includes an axis parallel to the first straight line and the second straight line, and the silicon rod rotates by a preset angle including:
[0012] The silicon rod is rotated 180° around the axis.
[0013] In some embodiments, the cutting line is cut according to a first feed speed curve to form the first slit, and the cutting line is cut according to a second feed speed curve to form the second slit, and the first feed speed curve and the second feed speed curve are curves of the feed speed of the cutting line changing with time;
[0014] The first feed speed profile includes the second feed speed profile, or the second feed speed profile includes the first feed speed profile.
[0015] In some embodiments, when the cutting wire is a loop wire, the cutting wire is fed at a constant feeding speed.
[0016] In some embodiments, when the cutting wire is a diamond wire, the cutting wire is fed at a variable feeding speed.
[0017] In some embodiments, the first distance is equal to the second distance.
[0018] In some embodiments, the silicon rod includes a first side, a second side, and a third side that are perpendicular to each other, the length of the first side is greater than the lengths of the second side and the third side, and the first straight line and the second straight line are both parallel to the first side.
[0019] In some embodiments, the first portion includes a first cut surface, the second portion includes a second cut surface, and the method further includes:
[0020] Grinding a first boundary area of the first cut surface; the first boundary area includes a connection area between the first cut seam and the second cut seam;
[0021] And / or, polishing a second boundary area of the second cut surface; the second boundary area includes a connection area between the first cut and the second cut.
[0022] In another aspect, a silicon rod cutting machine is provided.
[0023] A positioning device, used for clamping and positioning the silicon rod;
[0024] A control device is used to control the cutting device and the positioning device to execute the silicon rod cutting method.
[0025] The silicon rod cutting method and silicon rod cutting machine provided in the embodiment of the present application first use the cutting line to cut a first distance along the first straight line from the first side toward the second side to form a first slit on the silicon rod, and then use the cutting line to cut a second distance along the second straight line from the second side toward the first side to form a second slit on the silicon rod, and the second slit is completely connected to the first slit. Since the cutting line first cuts the first distance along the first straight line, when the cutting line cuts through the square silicon rod along the second straight line, the cutting area is far away from the edge of the square silicon rod, thereby improving the problem of edge collapse and notches on the edges of the square silicon rod. In addition, since the defects generated in the cutting area are far away from the edges, they can be repaired by subsequent processes such as grinding, so there is no need to reduce the feed speed of the cutting line before cutting through the square silicon rod, thereby ensuring production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0027] Figure 1 The schematic diagram of the cutting wire cutting a square silicon rod in an ideal state is schematically shown;
[0028] Figure 2 A schematic diagram showing a wire bow when a cutting wire cuts a square silicon rod is shown;
[0029] Figure 3 The schematic diagram shows the locations where edge collapse and notches are likely to occur in a half silicon rod;
[0030] Figure 4 A flow chart of a silicon rod cutting method is schematically shown;
[0031] Figure 5 The schematic diagram of the silicon rod after the first slit is formed is schematically shown;
[0032] Figure 6 Schematically shows the schematic diagram of the square silicon rod cutting process;
[0033] Figure 7 The schematic diagram after the square silicon rod is cut is shown schematically;
[0034] Figure 8 The structural block diagram of the control device is schematically shown.
[0035] Reference numerals:
[0036] 1 – cutting wheel;
[0037] 2 – cutting line;
[0038] 10-square silicon rod;
[0039] 11 - first side;
[0040] 12 - second side;
[0041] 13 - first incision;
[0042] 14 - second incision;
[0043] 10a - Part I;
[0044] 10b – Part II. DETAILED DESCRIPTION
[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.
[0046] First, several concepts in the embodiments of the present application are introduced.
[0047] A square silicon rod refers to a silicon rod that is rectangular as a whole. The square silicon rod includes end faces at both ends of the square silicon rod and four side faces between the two end faces. The end faces of the square silicon rod can be square or rectangular. The axis of the square silicon rod refers to a virtual line that passes through the geometric center of the end face and is perpendicular to the end face.
[0048] The square silicon rod can be obtained by cutting the round silicon rod into a square shape. The round silicon rod refers to a silicon rod that is cylindrical in shape. The square silicon rod can be a square silicon rod made of single crystal silicon material or a square silicon rod made of polycrystalline silicon material.
[0049] Photovoltaic cells are made from silicon wafers, which are sliced from square silicon rods in a direction perpendicular to the axis. With the development of the photovoltaic industry, the size of photovoltaic cells is increasing, and the size of silicon wafers is also increasing accordingly. These include small-sized silicon wafers, which are smaller than those obtained by directly slicing silicon rods.
[0050] Currently, there are only two ways to process small-size silicon wafers.
[0051] Method 1: Slice the square silicon rod to get silicon wafers, and then cut the silicon wafers into small-sized silicon wafers. The small-sized silicon wafers cut are prone to defects such as edge collapse and hidden cracks, and are not easy to repair.
[0052] Method 2: Cut the square silicon rod in half to obtain two half silicon rods, and slice the half silicon rods to obtain small-sized silicon wafers.
[0053] When the square silicon rod is cut in half, the cutting wire is used to cut the square silicon rod. Figure 1 As shown, in an ideal state, when the cutting wheel 1 drives the cutting wire 2 to feed downward to cut the square silicon rod 10, the cutting wire 2 is in a straight state. However, since the cutting wire 2 is flexible, Figure 2 As shown, when the cutting wheel 1 drives the cutting wire 2 to feed downward, the cutting wire 2 is prone to produce a wire bow under the action of the square silicon rod 10, that is, the cutting wire 2 bends and generates tension. Due to the existence of the wire bow of the cutting wire 2, the edges of the half silicon rod formed by cutting at the exit of the knife are prone to chipping and notching. Figure 3 The area indicated by the seven-pointed star is the location where edge collapse and notch are prone to occur. In order to reduce the edge collapse and notch defects caused by wire bow, the feed speed of the cutting wire 2 needs to be reduced before the cutting wire 2 cuts through the square silicon rod to reduce the curvature and tension of the wire bow. However, reducing the feed speed of the cutting wire 2 will reduce the cutting efficiency and increase the production cost.
[0054] In view of this, the embodiments of the present application provide a silicon rod cutting method and a silicon rod cutting machine, which improve the edge collapse and notch defects of half silicon rods while taking into account production efficiency.
[0055] The silicon rod cutting method provided in the embodiment of the present application is used to cut square silicon rods using a silicon rod cutting machine. The silicon rod cutting machine may include a cutting device, a positioning device, and a control device.
[0056] The cutting device is used to cut the square silicon rod. For example, the cutting device may include a cutting wheel and a cutting wire wound around the cutting wheel. During the cutting process, the cutting wheel may drive the cutting wire to move around the cutting wheel and drive the cutting wire to feed.
[0057] The positioning device is used to clamp and position the square silicon rod.
[0058] The control device is used to control the cutting device and the positioning device. Exemplarily, the control device includes a processor and a memory, the memory stores a control program, and the processor can read and execute the control program in the memory, thereby controlling the cooperation between the cutting device and the positioning device to achieve the cutting of the square silicon rod.
[0059] Figure 4 The flowchart of the silicon rod cutting method is schematically shown. Figure 4 As shown, the silicon rod cutting method includes the following steps.
[0060] S100, the cutting line cuts along a first straight line from the first side surface toward the second side surface by a first distance to form a first slit in the silicon rod.
[0061] The four side surfaces of the square silicon rod include a first side surface and a second side surface which are arranged opposite to each other.
[0062] For example, Figure 5 The upper middle side surface is the first side surface 11 .
[0063] The first straight line is located inside the first side surface 11. When cutting starts, part of the cutting line overlaps with the first straight line. During the cutting process, the cutting line advances from the first side surface 11 toward the second side surface, so that the first slit 13 extends from the first straight line toward the second side surface.
[0064] Exemplarily, the first straight line is a center line of the first side surface 11 .
[0065] Continue to refer Figure 5 The first distance a is smaller than the distance between the first side surface 11 and the second side surface, so that the first slit 13 cannot penetrate the square silicon rod.
[0066] In specific applications, the control device may control the cutting device according to the control program so that the cutting line cuts the first distance a along the first straight line from the first side surface 11 toward the second side surface. The cutting device may also be manually controlled so that the cutting line cuts the first distance a along the first straight line from the first side surface 11 toward the second side surface.
[0067] S200, the cutting line cuts along a second straight line from the second side surface toward the first side surface by a second distance to form a second slit in the silicon rod.
[0068] For example, Figure 6 The side surface at the lower middle portion is the second side surface 12 .
[0069] The second straight line is located inside the second side surface 12, and the second straight line is parallel to and directly opposite to the first straight line. When cutting starts, a portion of the cutting line overlaps with the second straight line, and during the cutting process, the cutting line is fed from the second side surface 12 toward the first side surface, so that the second slit extends from the second straight line toward the first side surface.
[0070] Exemplarily, the second straight line is a center line of the second side surface 12 .
[0071] in, Figure 6 The case where the cutting distance of the cutting line along the second straight line is less than the second distance is shown in FIG. 1 . At this time, there is still a region b between the first slit 13 and the second slit 14, that is, the second slit 14 is not connected to the first slit 13, and the square silicon rod is not separated by the first slit 13 and the second slit 14.
[0072] Figure 7The case where the cutting distance of the cutting line along the second straight line is equal to the second distance is shown in FIG. At this time, the area b between the first slit 13 and the second slit 14 is cut through, the second slit 14 is completely connected with the first slit 13, and the square silicon rod is divided into the first part 10a and the second part 10b by the first slit 13 and the second slit 14, and the first part 10a and the second part 10b can be half silicon rods.
[0073] Since the position where the square silicon rod is prone to edge collapse and notches during the cutting process is the position of the knife edge, that is, the position where the square silicon rod is cut through. In the embodiment of the present application, the square silicon rod is cut through in area b, so the cutting defects during the cutting are likely to appear in area b, but not on the edges, solving the problem of edge collapse and notches on the edges of the square silicon rod. In addition, since the cutting defects generated in area b can be repaired by subsequent processes such as grinding, there is no need to reduce the feed speed of the cutting line before cutting through area b, thereby ensuring production efficiency.
[0074] The second distance may be smaller than the distance between the first side and the second side. For example, the second distance is slightly larger than the difference between the distance between the first side and the second side and the first distance. For example, the first distance is equal to the second distance.
[0075] In specific applications, the control device may control the cutting device according to the control program so that the cutting line cuts the second distance along the second straight line from the second side toward the first side. The cutting device may also be manually controlled so that the cutting line cuts the first distance along the second straight line from the second side toward the first side.
[0076] The silicon rod cutting method provided in the embodiment of the present application first uses a cutting line to cut a first distance along a first straight line from the first side toward the second side to form a first slit on the silicon rod, and then uses a cutting line to cut a second distance along a second straight line from the second side toward the first side to form a second slit on the silicon rod, and the second slit is completely connected to the first slit. Since the cutting line first cuts the first distance along the first straight line, when the cutting line cuts through the square silicon rod along the second straight line, the cut-through area is far away from the edge of the square silicon rod, thereby improving the problem of edge collapse and notches on the edges of the square silicon rod. In addition, since the defects generated in the cut-through area are far away from the edges, they can be repaired by subsequent processes such as grinding, so there is no need to reduce the feed speed of the cutting line before cutting through the square silicon rod, thereby ensuring production efficiency.
[0077] The first slit and the second slit may be formed by cutting with the same cutting line or by cutting with different cutting lines.
[0078] Exemplarily, the silicon rod cutting machine includes a first cutting line and a second cutting line, wherein the first cutting line is arranged opposite to the first side surface, and the second cutting line is arranged opposite to the second side surface. The first cutting line is used to cut a first distance along the first straight line toward the second side surface. The second cutting line is used to cut a second distance along the second straight line toward the first side surface. The second cutting line may start cutting after the first cutting line is cut, or the first cutting line may start cutting after the second cutting line is cut, or the first cutting line and the second cutting line may cut at the same time to improve cutting efficiency.
[0079] When the first slit and the second slit are formed by cutting with the same cutting line, after forming the first slit and before forming the second slit, the silicon rod cutting method further includes the following steps.
[0080] S101, the cutting line exits the first cutting seam.
[0081] Specifically, the cutting wheel drives the cutting wire to move in a direction away from the second side surface, so that the cutting wire escapes from the first slit. In order to prevent the square silicon rod from contacting the cutting wire during rotation, a gap can be reserved between the cutting wire and the square silicon rod after the cutting wire exits the first slit.
[0082] Exemplarily, the square silicon rod rotates along an axis parallel to the first side surface and the second side surface, and after the cutting line exits the first slit, the distance between the cutting line and the first side surface is greater than the distance between the diagonal lines of the end surface of the square silicon rod. For example, the distance between the cutting line and the first side surface is greater than the length of the diagonal line of the end surface of the square silicon rod by more than 10 mm.
[0083] S102, the square silicon rod is rotated by a preset angle so that the second side surface faces the cutting line.
[0084] In actual application, the positioning device of the silicon rod cutting machine clamps and positions the square silicon rod. When the square silicon rod needs to be rotated, the positioning device drives the square silicon rod to rotate a preset angle.
[0085] In order to improve the position accuracy of the square silicon rod after rotation, the positioning device may include a servo motor, a harmonic reducer, and a positioning mechanism connected to the harmonic reducer. The positioning mechanism clamps and positions the silicon rod, and the servo motor drives the positioning mechanism to rotate through the harmonic reducer, thereby improving the position accuracy of the silicon rod. Wherein, the servo motor and the harmonic reducer may be provided at both ends of the square silicon rod, or the servo motor and the harmonic reducer may be provided at one end of the square silicon rod, and a bearing may be provided at the other end of the square silicon rod.
[0086] Of course, after the cutting line exits from the first slit, the cutting line may be rotated by a preset angle so that the cutting line faces the second side surface.
[0087] In some embodiments, the silicon rod is rotated by a preset angle in step S102, comprising: the square silicon rod is rotated 180° around an axis, and the axis is parallel to the first straight line and the second straight line.
[0088] The square silicon rod rotates around an axis parallel to the first straight line and the second straight line, so that the envelope surface of the motion trajectory of the square silicon rod during the rotation process is smaller, thereby reducing space occupancy and preventing the silicon rod from colliding with other components during the rotation process.
[0089] Exemplarily, the positioning mechanism in the positioning device clamps two end faces of the square silicon rod, so that the square silicon rod can rotate around an axis parallel to the first straight line and the second straight line.
[0090] In some embodiments, the cutting line is cut according to a first feed speed curve to form a first slit, and the cutting line is cut according to a second feed speed curve to form a second slit. The first feed speed curve and the second feed speed curve are curves showing the feed speed of the cutting line changing with time.
[0091] The cutting wire can be fed at a constant speed during cutting, and the feed speed curve is a straight line parallel to the time axis; the cutting wire can also be fed at a variable speed during cutting, and the feed speed curve is a straight line or curve inclined to the time axis.
[0092] During the cutting process, the feed speed of the cutting line will affect the cutting track, that is, the position of the slit. In order to make the first slit and the second slit face each other, the first feed speed curve includes the second feed speed curve, or the second feed speed curve includes the first feed speed curve.
[0093] The first feed speed curve includes the second feed speed curve, which means that the second feed speed curve is a part of the first feed speed curve. The second feed speed curve includes the first feed speed curve, which means that the first feed speed curve is a part of the second feed speed curve.
[0094] The first feed speed curve includes the second feed speed curve, or the second feed speed curve includes the first feed speed curve, so that the positions of the first slit and the second slit are closer to the facing position, thereby making the boundary area of the first slit and the second slit smoother.
[0095] Exemplarily, the first feed speed curve is the same as the second feed speed curve. For example, in the control program stored in the control device, the program for controlling the cutting line to form the first slit is the same as the program for controlling the cutting line to form the second slit.
[0096] In some embodiments, when the cutting wire is a loop wire, the cutting wire is fed at a constant feeding speed. When the cutting wire is a loop wire, the cutting wire may not be reversed during the cutting process, and the cutting wire may be fed at a constant feeding speed.
[0097] In some embodiments, when the cutting wire is a diamond wire, the cutting wire is fed at a variable feed speed. When the cutting wire is a diamond wire, in order to reduce the length of the cutting wire, it is usually necessary to change direction during the cutting process, and the cutting wire is fed at a variable feed speed.
[0098] Exemplarily, when the cutting line slides along the cutting wheel in a first direction, the feeding speed of the cutting line is first accelerated, then uniform, and then decelerated; when the cutting line slides along the cutting wheel in an opposite second direction, the feeding speed of the cutting line is first accelerated, then uniform, and then decelerated.
[0099] The silicon rod comprises a first side, a second side and a third side which are perpendicular to each other. The length of the first side is greater than the lengths of the second side and the third side. The first straight line and the second straight line are both parallel to the first side.
[0100] In some embodiments, the silicon rod cutting method may further include:
[0101] S201, grinding a first boundary area of a first section.
[0102] The first cut surface is located in the first part, and the first cut surface is a cut surface formed by cutting the square silicon rod by the cutting line. The first junction area includes the connection area of the first cut seam and the second cut seam.
[0103] During the cutting process, the square silicon rod is cut through in the first interface area, so cutting defects are likely to occur in the first interface area. Grinding the first interface area can repair the defects caused by cutting.
[0104] In some embodiments, the silicon rod cutting method may further include:
[0105] S202, grinding the second boundary area of the second section.
[0106] The second cut surface is located in the second part, the second cut surface is a cut surface formed by cutting the square silicon rod by the cutting line, and the first cut surface and the second cut surface are opposite to each other. The second boundary area includes the connection area of the first cut seam and the second cut seam.
[0107] During the cutting process, the square silicon rod is cut through in the second interface area, so cutting defects are likely to occur in the second interface area. Grinding the second interface area can repair the defects caused by cutting.
[0108] The embodiment of the present application further provides a silicon rod cutting machine, which includes a cutting device, a positioning device and a control device.
[0109] The cutting device is used to cut the square silicon rod. For example, the cutting device may include a cutting wheel and a cutting wire wound around the cutting wheel. During the cutting process, the cutting wheel can drive the cutting wire to move around the cutting wheel and drive the cutting wire to feed. The cutting wire can be a loop wire or a diamond wire. The embodiment of the present application does not limit the type of the cutting wire.
[0110] The positioning device is used to clamp and position the square silicon rod. The positioning device may include a servo motor, a harmonic reducer, and a positioning mechanism connected to the harmonic reducer. The positioning mechanism clamps and positions the silicon rod. The servo motor drives the positioning mechanism to rotate through the harmonic reducer, thereby improving the position accuracy of the silicon rod. The servo motor and the harmonic reducer may be provided at both ends of the square silicon rod, or the servo motor and the harmonic reducer may be provided at one end of the square silicon rod, and a bearing may be provided at the other end of the square silicon rod.
[0111] The control device is used to control the cutting device and the positioning device. Figure 8 As shown, the control device 100 includes a processor 110 and a memory 120. The memory 120 stores a control program. The processor 110 can read and execute the control program in the memory 120, thereby controlling the cutting device and the positioning device to cooperate to execute the silicon rod cutting method and realize the cutting of square silicon rods.
[0112] The silicon rod cutting machine provided in the embodiment of the present application first uses a cutting line to cut a first distance along a first straight line from the first side toward the second side to form a first slit on the silicon rod, and then uses a cutting line to cut a second distance along a second straight line from the second side toward the first side to form a second slit on the silicon rod, and the second slit is completely connected to the first slit. Since the cutting line first cuts the first distance along the first straight line, when the cutting line cuts through the square silicon rod along the second straight line, the cut-through area is far away from the edge of the square silicon rod, thereby improving the problem of edge collapse and notches on the edges of the square silicon rod. In addition, since the defects generated in the cut-through area are far away from the edges, they can be repaired by subsequent processes such as grinding, so there is no need to reduce the feed speed of the cutting line before cutting through the square silicon rod, thereby ensuring production efficiency.
[0113] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal 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 terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.
[0114] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.
[0115] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.
Claims
1. A silicon rod cutting method, for cutting a silicon rod using a silicon rod cutting machine, wherein the silicon rod cutting machine comprises a cutting wire, and the square silicon rod comprises a first side surface and a second side surface opposite to each other, characterized in that: The method comprises: The cutting line cuts a first distance along a first straight line from the first side surface toward the second side surface to form a first slit on the silicon rod; The cutting line cuts a second distance along a second straight line from the second side surface toward the first side surface, forming a second slit on the silicon rod; The first straight line is located on the first side surface, the second straight line is located on the second side surface, the first straight line and the second straight line are parallel and opposite to each other; the second slit is completely connected with the first slit, so that the silicon rod is divided into a first part and a second part by the first slit and the second slit.
2. The silicon rod cutting method according to claim 1, characterized in that: The first slit and the second slit are formed by cutting with the same cutting line, and after forming the first slit and before forming the second slit, the method further comprises: The cutting line exits the first slit; The silicon rod is rotated at a preset angle so that the second side surface faces the cutting line.
3. The silicon rod cutting method according to claim 2, characterized in that: The silicon rod comprises an axis parallel to the first straight line and the second straight line, and the silicon rod rotates by a preset angle comprising: The silicon rod is rotated 180° around the axis.
4. The silicon rod cutting method according to any one of claims 1 to 3, characterized in that: The cutting line is cut according to a first feed speed curve to form the first slit, and the cutting line is cut according to a second feed speed curve to form the second slit, and the first feed speed curve and the second feed speed curve are curves showing the feed speed of the cutting line changing with time; The first feed speed profile includes the second feed speed profile, or the second feed speed profile includes the first feed speed profile.
5. The silicon rod cutting method according to claim 4, characterized in that: When the cutting line is a loop line, the cutting line is fed at a constant feeding speed.
6. The silicon rod cutting method according to claim 4, characterized in that: When the cutting wire is a diamond wire, the cutting wire is fed at a variable feeding speed.
7. The silicon rod cutting method according to any one of claims 1 to 3, characterized in that: The first distance is equal to the second distance.
8. The silicon rod cutting method according to any one of claims 1 to 3, characterized in that: The silicon rod comprises a first side, a second side and a third side which are perpendicular to each other, the length of the first side is greater than the lengths of the second side and the third side, and the first straight line and the second straight line are both parallel to the first side.
9. The silicon rod cutting method according to any one of claims 1 to 3, characterized in that: The first portion includes a first section, the second portion includes a second section, and the method further includes: Grinding a first boundary area of the first cut surface; the first boundary area includes a connection area between the first cut seam and the second cut seam; And / or, polishing a second boundary area of the second cut surface; the second boundary area includes a connection area between the first cut and the second cut.
10. A silicon rod cutting machine, characterized in that: include: A cutting device for cutting silicon rods; A positioning device, used for clamping and positioning the silicon rod; A control device, used for controlling the cutting device and the positioning device to perform the silicon rod cutting method according to any one of claims 1 to 8.