Silicon rod cutting system and cutting process

Abstract

The application provides a silicon rod cutting system and a cutting process, which comprises a cutting roller shaft group provided with a cutting wire net and an auxiliary roller shaft group provided with an auxiliary wire net, the auxiliary roller shaft group is arranged in a space formed by the cutting wire net and the cutting roller shaft group, the auxiliary wire net is arranged on a side of the cutting wire net away from a single crystal silicon rod, a distance is provided between the auxiliary wire net and the cutting wire net, and the arrangement specification of the auxiliary wire net is consistent with that of the cutting wire net, so that a certain gap is provided between any cutting wire in the cutting wire net and the auxiliary wire corresponding to the cutting wire, and the flow of cooling liquid is realized. The auxiliary wire separates two adjacent silicon wafers, so that a certain gap is provided below the cutting position of the silicon wafer in the cutting process, the entering depth of the cooling liquid is increased, the cooling liquid chip removal capacity is improved, the wear of the cutting wire is reduced, the entering depth of the cooling liquid is increased, the cooling liquid chip removal capacity is improved, and the wear of the cutting wire is reduced.

Description

Technical Field

[0001] This invention belongs to the field of silicon wafer cutting technology, and in particular relates to a silicon rod cutting system and cutting process. Background Technology

[0002] In the current silicon wafer cutting field, with the advancement of wire thinning, the cutting lines for silicon wafers are becoming increasingly fine. During the cutting process, the spacing between adjacent silicon wafers decreases, making them more prone to adhering together. This makes it difficult for coolant to be carried into the cutting line for dicing, resulting in wire breakage during the cutting process and increased TTV and color difference in the cut silicon wafers.

[0003] To address the issue of poor coolant carrying capacity during the thinning process, current solutions involve increasing coolant flow and pressure, and employing a forward and reverse cutting process to carry coolant at both ends of the incoming and outgoing cuts, thereby increasing the coolant penetration depth during the slicing process. However, while this method increases the coolant penetration depth at both ends of the silicon wafer, the amount of coolant is still insufficient when cutting the middle section of the silicon ingot, resulting in a significant color difference between the middle and both ends of the cut silicon wafer. Summary of the Invention

[0004] In view of the above problems, the present invention provides a silicon rod cutting system and cutting process to solve the above or other problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a silicon rod cutting system, including a cutting roller assembly with a cutting wire mesh, and an auxiliary roller assembly with an auxiliary wire mesh. The auxiliary roller assembly is located in the space formed by the cutting wire mesh and the cutting roller assembly. The auxiliary wire mesh is located on the side of the cutting wire mesh away from the single crystal silicon rod. There is a distance between the auxiliary wire mesh and the cutting wire mesh, and the layout specifications of the auxiliary wire mesh are consistent with the layout specifications of the cutting wire mesh, so that there is a certain gap between any cutting line in the cutting wire mesh and the corresponding auxiliary line, allowing the flow of coolant.

[0006] Furthermore, the cutting area of ​​the cutting mesh is set parallel to the segmentation area of ​​the auxiliary mesh, and in the direction perpendicular to the cutting mesh, multiple cutting lines in the cutting area of ​​the cutting mesh correspond one-to-one with multiple auxiliary lines in the segmentation area of ​​the auxiliary mesh.

[0007] Furthermore, the auxiliary roller assembly includes at least two auxiliary rollers, and the cutting roller assembly includes at least two main cutting rollers. The two auxiliary rollers are located between the two main cutting rollers, and the diameter of the auxiliary rollers is smaller than the diameter of the main cutting rollers.

[0008] Furthermore, in the vertical direction of the cutting wire mesh, the distance between the axis of the auxiliary roller and the cutting wire mesh is not less than the wire bow value of the cutting wire mesh.

[0009] Furthermore, the distance between the auxiliary wire mesh and the cutting wire mesh shall not be greater than the first distance, which is 5-10mm.

[0010] Furthermore, the distance between adjacent auxiliary rollers and the main cutting roller is the second distance, which is 100-110mm.

[0011] Furthermore, the diameter of the auxiliary lines constituting the auxiliary wire mesh is no greater than the diameter of the cutting lines constituting the cutting wire mesh.

[0012] Furthermore, one of the auxiliary rollers in the auxiliary roller group is connected to a drive device, or one of the auxiliary rollers in the auxiliary roller group is connected to one of the main cutting rollers in the cutting roller group via a transmission device.

[0013] A silicon rod cutting process, employing the silicon rod cutting system described above to cut a single-crystal silicon rod, includes the following steps:

[0014] Connect one main cutting roller shaft in the cutting roller shaft group to one auxiliary roller shaft in the auxiliary roller shaft group. The main cutting roller shaft drives the auxiliary roller shaft to rotate, performing the initial wiring of the cutting wire mesh and the initial wiring of the auxiliary wire mesh respectively.

[0015] After the initial wiring, the cutting lines in the initial wiring area on the main cutting roller and the auxiliary lines in the initial wiring area on the auxiliary roller are fixed respectively;

[0016] Perform automatic wiring;

[0017] After automatic wiring, the connection between the main cutting roller and the auxiliary roller is disconnected to cut the monocrystalline silicon rod;

[0018] In the process of cutting monocrystalline silicon, during the cutting stage, the feed speed, cutting line speed, and coolant flow rate are set as the feed position increases; during the material lifting stage, the feed speed and coolant flow rate are set as the feed position decreases.

[0019] Furthermore, when a main cutting roller in a cutting roller group is connected to an auxiliary roller in an auxiliary roller group, the connection includes:

[0020] The auxiliary rollers in the auxiliary roller assembly are connected by connectors, enabling multiple auxiliary rollers to rotate synchronously.

[0021] Fix the ends of the auxiliary line by wrapping the auxiliary line around the connector.

[0022] The main cutting rollers in the cutting roller assembly are connected by connectors, so that multiple main cutting rollers rotate synchronously.

[0023] Fix the end of the cutting wire and wrap the cutting wire around the connector.

[0024] A main cutting roller shaft is connected to an auxiliary roller shaft via a transmission device, so that the main cutting roller shaft can drive the auxiliary roller shaft to rotate.

[0025] Furthermore, when performing the initial routing of the cut net and the initial routing of the auxiliary net, it includes:

[0026] The initial routing of the cutting line and the initial routing of the auxiliary line are performed manually. The initial width of the cutting line is 3-6mm, and the initial width of the auxiliary line is 3-6mm.

[0027] Furthermore, during the cutting stage, the cutting line speed is 35-45 m / s, the coolant flow rate is 240-270 L / min, and the feed rate is 2-2.5 mm / min.

[0028] Furthermore, during the feeding stage, the feed rate is 20-55 mm / min, and the coolant flow rate is 200-240 L / min.

[0029] Due to the adoption of the above technical solution, an auxiliary roller assembly is provided. This auxiliary roller assembly is set within the space formed by the cutting roller assembly and the cutting mesh. An auxiliary mesh is provided on the auxiliary roller assembly, located on the side of the cutting mesh away from the monocrystalline silicon rod. The auxiliary mesh is set parallel to the cutting mesh, and the layout specifications of the auxiliary lines in the auxiliary mesh are consistent with the layout specifications of the cutting lines in the cutting mesh. Each auxiliary line in the auxiliary mesh corresponds one-to-one with each cutting line in the cutting mesh, and there is a certain distance between the auxiliary mesh and the cutting mesh. When the cutting mesh cuts the monocrystalline silicon rod, each auxiliary line in the auxiliary mesh is located a certain distance below the corresponding cutting line. The auxiliary lines separate two adjacent silicon wafers, so that there is a certain gap below the cut point of the silicon wafer during the cutting process, which increases the penetration depth of the coolant, improves the chip removal capacity of the coolant, and reduces the wear of the cutting lines. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a cutting system with an auxiliary roller assembly according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the cutting process of a single-crystal silicon rod according to an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the wire bow structure of the cutting wire mesh during the cutting of a single-crystal silicon rod according to an embodiment of the present invention;

[0033] Figure 4 This is a simplified structural diagram of the wire bow of the cutting wire mesh during the cutting of a single-crystal silicon rod according to an embodiment of the present invention.

[0034] In the picture:

[0035] 1. Main roller shaft 2. Cutting line 3. Auxiliary roller shaft

[0036] 4. Auxiliary lines; 5. Transmission device; 6. Single crystal silicon rod

[0037] 7. Silicon wafers Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0039] Figure 1 A schematic diagram of an embodiment of the present invention is shown. This embodiment relates to a silicon rod cutting system and cutting process for cutting monocrystalline silicon rods. The silicon rod cutting system has an auxiliary roller group with an auxiliary wire mesh, and the wiring specifications of the auxiliary wire mesh are consistent with the layout specifications of the cutting wire mesh. This increases the gap below the cutting line at the silicon wafer cutting point during the cutting process, increases the penetration depth of the coolant, improves the chip removal capacity of the coolant, reduces the wear of the cutting line, reduces the TTV of the silicon wafer, reduces color difference, and improves the cutting quality of the silicon wafer.

[0040] A silicon rod cutting system, such as Figure 1 and 2 As shown, the device includes a cutting roller assembly with a cutting wire mesh, on which cutting wires 2 are wound to form a cutting wire mesh, which is used to cut the monocrystalline silicon rod 6. It also includes an auxiliary roller assembly with an auxiliary wire mesh, located within the space formed by the cutting wire mesh and the cutting roller assembly. The auxiliary wire mesh is located on the side of the cutting wire mesh away from the monocrystalline silicon rod 6, that is, below the cutting wire mesh, and its layout specifications are consistent with those of the cutting wire mesh. The cutting wire mesh cuts the monocrystalline silicon rod 6, resulting in... Multiple silicon wafers 7, with auxiliary lines 4 forming an auxiliary mesh located between adjacent silicon wafers 7, separating them. The auxiliary mesh extends the length of the gap below the cutting line 2 between adjacent silicon wafers 7, creating a flow channel below the cutting line 2 at the silicon wafer 7 cutting point. Here, adjacent silicon wafers 7 do not contact each other, and coolant can flow along this flow channel, increasing the coolant penetration depth, improving the coolant chip removal capacity, reducing wear on the cutting line, reducing TTV of the silicon wafer 7, reducing color difference, and improving the cutting quality of the silicon wafer 7.

[0041] Specifically, such as Figure 1 and 2As shown, the cutting roller assembly includes at least two main rollers 1 and a cutting wire mesh. The main rollers 1 are grooved rollers with multiple grooves so that the cutting wires 2 can be wound around each main roller 1. Along the axial direction of the main rollers 1, the cutting wires 2 are wound sequentially in each groove. The cutting wires 2 are located in the grooves, forming the structure of the cutting wire mesh. Since the monocrystalline silicon rod 6 has a certain width and thickness, in order to facilitate the cutting of the monocrystalline silicon rod 6 by the cutting wire mesh, there is a certain distance between two adjacent main rollers 1 in the horizontal direction, which is greater than the width of the monocrystalline silicon rod 6. There is also a certain distance between two adjacent main rollers 1 in the vertical direction, which is greater than the thickness of the monocrystalline silicon rod 6. This ensures that during the cutting process, each main roller 1 will not interfere with the feeding motion of the monocrystalline silicon rod 6. Furthermore, the cutting lines 2 are wound around multiple main rollers 1. The mesh area formed by the cutting lines 2 located between two horizontally positioned main rollers 1 cuts the monocrystalline silicon rod 6. These two main rollers 1 are set as the main cutting rollers. The distance between the two main cutting rollers can be 400-420mm, and the diameter of the main cutting rollers can be 160-180mm. The distance between the two main cutting rollers and the diameter of the main cutting rollers can be selected according to actual needs, and no specific requirements are made here.

[0042] Two main cutting rollers, along with other main rollers 1 that serve as auxiliary cutting lines 2 and the cutting wire mesh, form a receiving space. During the cutting process of the monocrystalline silicon rod 6, the silicon wafer 7 formed from the cut monocrystalline silicon rod 6 gradually enters this receiving space. The auxiliary roller group is set within this receiving space, and the auxiliary wire mesh on the auxiliary roller group is located inside (below) the cutting wire mesh. The auxiliary wire mesh has a segmented area corresponding to the cutting area of ​​the cutting wire mesh. This segmented area is located below the cutting area of ​​the cutting wire mesh. When the monocrystalline silicon rod 6 is cut in the cutting area of ​​the cutting wire mesh, each auxiliary line 4 in the segmented area of ​​the auxiliary wire mesh is located at any... Between two adjacent silicon wafers 7, the auxiliary line 4 is separated from the dicing line 2. Therefore, the auxiliary line 4 can reduce the length of adsorption between adjacent silicon wafers 7 and extend the gap length below the dicing line 2. This allows the single crystal silicon rod 6 to have a certain length of gap between the silicon wafer 7 and the dicing line 2 at a certain distance during the dicing process. This distance is greater than the gap length below the dicing line 2 in the prior art when no auxiliary line is set. Therefore, the existence of this gap and the increase in the gap length can increase the penetration depth of the coolant, improve the chip removal capacity of the coolant, and reduce the wear of the dicing line 2.

[0043] Therefore, when setting up the auxiliary mesh, the layout specifications of the auxiliary mesh are consistent with those of the cutting mesh. Multiple cutting lines 2 in the cutting area of ​​the cutting mesh correspond one-to-one with multiple auxiliary lines 4 in the segmented area of ​​the auxiliary mesh. Each cutting line 2 is accompanied by an auxiliary line 4 below it. Since the single-crystal silicon rod 6 is fed vertically during the cutting process, in the vertical direction, a corresponding set of cutting lines 2 and auxiliary lines 4 are located in the same plane. Therefore, the multiple cutting lines 2 in the cutting area of ​​the cutting mesh and the corresponding auxiliary lines 4 in the segmented area of ​​the auxiliary mesh... The auxiliary lines 4 form multiple parallel planes arranged vertically. Each plane contains a set of cutting lines 2 and auxiliary lines 4. The cutting lines 2 in each plane cut the monocrystalline silicon rod 6. The auxiliary lines 4 are located below the cutting lines 2 and separate the silicon wafers 7 that are adsorbed together after cutting. This increases the length of the gap below the cutting lines 2 at the cutting point. Given the width of the monocrystalline silicon rod 6, this gap forms a flow channel in the width direction of the monocrystalline silicon rod 6. Coolant can flow in this flow channel, increasing the depth of coolant penetration so that coolant can participate in the cutting.

[0044] In the above structure, the number of auxiliary lines 4 in the segmented area of ​​the auxiliary wire mesh is the same as the number of cutting lines 2 in the segmented area of ​​the cutting wire mesh. Of course, the number of auxiliary lines 4 in the segmented area of ​​the auxiliary wire mesh is not the same as the number of cutting lines 2 in the segmented area of ​​the cutting wire mesh; the number of auxiliary lines 4 in the segmented area of ​​the auxiliary wire mesh is less than the number of cutting lines 2 in the segmented area of ​​the cutting wire mesh. However, in this structure, each auxiliary line 4 corresponds to one cutting line 2, and each auxiliary line 4 is located below one cutting line 2, forming multiple sets of cutting lines 2 and auxiliary lines 4 to cut the monocrystalline silicon rod 6 and separate adjacent silicon wafers 7. The number of auxiliary lines 4 in the segmented area of ​​the auxiliary wire mesh is selected according to actual needs.

[0045] To avoid interference between the cutting wire mesh and the auxiliary wire mesh during the cutting of the single-crystal silicon rod 6, a certain distance is maintained between them. This distance is no greater than a first distance, which is 5-10mm. This first distance is selected based on actual needs and is not specifically required here. This distance ensures that there is a certain length of gap below the cutting line 2 at the cutting point, thereby increasing the penetration depth of the coolant.

[0046] The aforementioned auxiliary roller assembly includes at least two auxiliary rollers 3. Auxiliary lines 4 are wound around multiple auxiliary rollers 3 to form an auxiliary wire mesh. Each auxiliary roller 3 is a grooved roller with multiple grooves arranged along its axial direction. To ensure that the layout specifications of the auxiliary wire mesh are consistent with those of the cutting wire mesh, the shape and number of grooves on the auxiliary roller 3 are consistent with those on the main cutting roller. This ensures that the arrangement of the cutting lines 2 wound on the main roller 1 and the auxiliary lines 4 wound on the auxiliary roller 3 are consistent, and the gap between adjacent cutting lines 2 is consistent with the gap between adjacent auxiliary lines 4. This ensures that multiple cutting lines 2 in the cutting area of ​​the cutting wire mesh correspond one-to-one with multiple auxiliary lines 4 in the segmented area of ​​the auxiliary wire mesh.

[0047] To reduce the space occupied by the auxiliary wire mesh, the diameter of the auxiliary roller 3 is smaller than the diameter of the main roller 1 of the cutting roller group. The diameter of the auxiliary roller 3 is 12-18mm. The diameter of the auxiliary roller 3 is selected according to actual needs, and no specific requirements are made here.

[0048] The auxiliary roller group has at least two auxiliary rollers 3. The number of auxiliary rollers 3 is selected according to actual needs, and no specific requirements are specified here. The arrangement of different numbers of auxiliary rollers 3 is different. When there are two auxiliary rollers 3, the two auxiliary rollers 3 are set horizontally, and the plane on which the two auxiliary rollers 3 are located is parallel to the plane on which the two main cutting rollers are located. The distance between the two auxiliary rollers 3 is less than the distance between the two main cutting rollers. Auxiliary lines 4 are wound around the two auxiliary rollers 3, forming auxiliary wire meshes on the upper and lower sides of the two auxiliary rollers 3 respectively. Multiple auxiliary lines 4 in the auxiliary wire mesh on the upper side correspond one-to-one with multiple auxiliary lines 4 in the auxiliary wire mesh on the lower side. At the same time, multiple auxiliary lines 4 in the auxiliary wire mesh on the upper side correspond one-to-one with multiple cutting lines 2 in the cutting wire mesh on the two main cutting rollers, so that the cutting lines 2 cut the monocrystalline silicon rod 6 and the auxiliary lines 4 separate the cut silicon wafers 7.

[0049] In this structure, the distance between an adjacent set of auxiliary rollers 3 and the main cutting roller is the second distance, which is 100-110mm. This second distance is selected according to actual needs and is not specifically required here. The setting of the second distance avoids motion interference between the main cutting roller and the adjacent auxiliary rollers 3.

[0050] In this structure, the distance between the two auxiliary rollers 3 is 255-275mm. The distance between the two auxiliary rollers 3 is selected and set according to the distance between the two main cutting rollers, and no specific requirements are made here.

[0051] When the number of auxiliary rollers 3 is greater than two, the multiple auxiliary rollers 3 are divided into at least two groups, with at least two auxiliary rollers 3 in each group. The multiple auxiliary rollers 3 in each group are arranged in pairs. The multiple groups of auxiliary rollers 3 are arranged sequentially along the vertical direction (perpendicular to the direction of the cutting wire mesh). The two auxiliary rollers 3 in each group are arranged along the horizontal direction, so that the auxiliary wire mesh wound on the multiple groups of auxiliary rollers 3 is arranged parallel to the cutting wire mesh. When multiple sets of auxiliary rollers 3 are used to wind the auxiliary lines 4, there can be a single auxiliary line 4, which is sequentially wound around each set of auxiliary rollers 3. The auxiliary rollers 3 closest to the cutting mesh and the auxiliary rollers 3 farthest from the cutting mesh respectively form the dividing areas of the auxiliary mesh, thus separating the cut silicon wafers 7. Alternatively, there can be multiple auxiliary lines 4, the number of which is consistent with the number of sets of auxiliary rollers 3. Each auxiliary line 4 is wound around one set of auxiliary rollers 3, and each set of auxiliary rollers 3 forms an auxiliary mesh. Along the vertical direction, there are multiple auxiliary meshes, and the multiple auxiliary lines 4 in the dividing areas of the multiple auxiliary meshes correspond one-to-one. The winding method of the auxiliary lines 4 on the multiple sets of auxiliary rollers 3 can also be other settings, which can be selected according to actual needs. No specific requirements are specified here.

[0052] The number of auxiliary rollers 3 in the other group is at least one. The auxiliary rollers 3 in this group play the role of tensioning and supporting during the winding of the auxiliary line 4. The auxiliary rollers 3 in this group can be set to the lower side and / or left side and / or right side of the auxiliary rollers 3 in the previous group, depending on the actual needs. However, the auxiliary rollers 3 in this group will not interfere with the movement of the main cutting roller and other main rollers 1 and cutting lines 2 when set.

[0053] To avoid damage to adjacent silicon wafers 7 after cutting by the auxiliary mesh, the diameter of the auxiliary line 4 constituting the auxiliary mesh is no greater than the diameter of the cutting line 2 constituting the cutting mesh. The diameter of the auxiliary line 4 is selected according to actual needs, and no specific requirements are made here.

[0054] To avoid interference between the cutting wire mesh and the auxiliary wire mesh during the cutting of the single crystal silicon rod 6, the distance between the axis of the auxiliary roller 3 and the cutting wire mesh in the direction perpendicular to the cutting wire mesh is not less than the arc value of the cutting wire mesh. According to... Figure 3 and Figure 4 We can know that the formula for calculating the bow length is:

[0055]

[0056] Where w is the bow value, V f For the feed rate, V c Let l be the linear velocity. i For single crystal width, l w d is the spacing between the Geneva wheels.w Where is the wire diameter, F0 is the breaking tension of the cutting wire 2, and K is the wire diameter. p t is the Preston coefficient, and t is the cutting time.

[0057] As can be seen from the above formula for calculating the bow, the bow gradually changes over time and eventually stabilizes at a certain value. During the cutting of the single crystal silicon rod 6, the bow value of the cutting wire mesh remains at this stable value. The vertical distance between the cutting wire mesh and the axis of the auxiliary roller 3 close to the cutting wire mesh is set to be no less than the bow value of the cutting wire 2 of the cutting wire mesh, so that the auxiliary roller 3 is not affected by the bow of the cutting wire mesh.

[0058] In the auxiliary roller group, any one of the auxiliary rollers 3 is connected to a drive device. The drive device drives the auxiliary roller 3 to rotate. Through the auxiliary wire mesh, the auxiliary roller 3 can drive the other auxiliary rollers 3 to rotate, realizing the feeding and taking-up of the auxiliary wire mesh. That is, the auxiliary roller 3 connected to the drive device is the active roller. Of course, the auxiliary rollers 3 in the auxiliary roller group are not connected to a drive device. Any one of the auxiliary rollers 3 in the auxiliary roller group is connected to the active roller of the two main cutting rollers through a transmission device 5. The rotation of the main cutting roller drives the auxiliary roller 3 to rotate, so that the main roller 1 and the auxiliary roller 3 rotate synchronously.

[0059] The silicon rod cutting system will be described below with reference to a specific embodiment.

[0060] In this embodiment, there are two auxiliary rollers 3 in the auxiliary roller group. The two auxiliary rollers 3 are installed between the two main cutting rollers. The diameter of the auxiliary roller 3 is smaller than the diameter of the main cutting roller. The diameter of the auxiliary roller 3 can be 15mm, the diameter of the main cutting roller is 170mm, the distance between the two main cutting rollers is 400mm, the distance between the two auxiliary rollers 3 is 255mm, and the distance between each auxiliary roller 3 and the adjacent main cutting roller is 105mm. Auxiliary lines 4 are wound around two auxiliary rollers 3, sequentially along the axial direction of the auxiliary rollers 3 to form an auxiliary wire mesh, creating segmented areas on the upper and lower sides of the two auxiliary rollers 3 respectively. The cutting roller assembly includes two main cutting rollers and one main roller, which is located below the two main cutting rollers. Cutting lines 2 are wound around the two main cutting rollers and the main roller 2 to form a cutting wire mesh, creating a cutting area of ​​the cutting wire mesh on the upper side of the two main cutting rollers. The cutting area of ​​the cutting wire mesh corresponds to the segmented area of ​​the auxiliary wire mesh and is arranged parallel to it. Multiple cutting lines 2 in the cutting area correspond one-to-one with multiple auxiliary lines 4 in the segmented area. When installing the two auxiliary rollers 3, the bow value of the cutting wire mesh on the two main cutting rollers is calculated according to the formula for calculating the bow value. The vertical distance between the axis of the auxiliary roller 3 and the cutting wire mesh 2 is set according to this bow value to avoid the auxiliary roller 3 being affected by the cutting wire mesh.

[0061] During the cutting of the monocrystalline silicon rod 6, the monocrystalline silicon rod 6 moves towards the cutting wire mesh and is fed. The cutting lines 2 of the cutting area of ​​the cutting wire mesh cut the monocrystalline silicon rod 6 into multiple silicon wafers 7. As the monocrystalline silicon rod 6 is fed, each auxiliary line 4 of the auxiliary wire mesh enters between two adjacent silicon wafers 7 and is located between two adjacent silicon wafers 7. At the distance between the cutting line 2 and the auxiliary line 4 below the cutting line 2, the auxiliary line 4 separates two adjacent silicon wafers 7, so that there is a certain gap between the cutting line 2 and the auxiliary line 4. When there are multiple auxiliary lines 4, the gap below the cutting line 2 is further increased. The cutting line 2, the auxiliary line 4 and the two adjacent silicon wafers 7 can form a flow channel. During the cutting process, the coolant can flow in the flow channel. The flow channel is formed below each cutting line 2, which increases the penetration depth of the coolant, improves the chip removal capacity of the coolant, reduces the wear of the cutting line, reduces the TTV of the silicon wafer 7, reduces color difference, and improves the cutting quality of the silicon wafer 7.

[0062] A silicon rod cutting process, which uses the aforementioned silicon rod cutting system to cut a single crystal silicon rod 6, includes the following steps:

[0063] Connect a main roller 1 from the cutting roller assembly to an auxiliary roller 3 from the auxiliary roller assembly. The main roller 1 drives the auxiliary roller 3 to rotate, performing initial wiring of the cutting wire mesh and initial wiring of the auxiliary wire mesh respectively. This step includes:

[0064] Multiple auxiliary rollers 3 in the auxiliary roller group are connected by a connector, so that the multiple auxiliary rollers 3 rotate synchronously; in some feasible embodiments, the connector is preferably an adhesive tape, which is wrapped around the head of the multiple auxiliary rollers 3 in multiple turns to connect the multiple auxiliary rollers 3 together, so that the multiple auxiliary rollers 3 rotate synchronously.

[0065] Fix the end of the auxiliary line 4, pull out an auxiliary line 4 from the wire feeding shaft, and fix the auxiliary line 4 around the connector so that the auxiliary line 4 can be wound around the auxiliary roller shaft 3 later; when the connector is tape, stick the auxiliary line 4 to the tape and make multiple turns to fix the auxiliary line 4 on the tape.

[0066] Multiple main rollers 1 in the cutting roller assembly are connected by a connector, so that the multiple main rollers 1 rotate synchronously; in some feasible embodiments, the connector is preferably an adhesive tape, which will not damage the main rollers 1 and the auxiliary rollers 3. The adhesive tape is wrapped around the head of the multiple main rollers 1 in multiple turns to connect the multiple main rollers 1 together, so that the multiple main rollers 1 rotate synchronously.

[0067] Fix the end of the cutting wire 2, pull out a cutting wire 2 from the feed shaft, pass the cutting wire 2 around the tension pulley group, tighten the cutting wire 2, and fix the cutting wire 2 to the connector so that the cutting wire 2 can be wound on the main roller shaft 1 later; when the connector is a tape, stick the cutting wire 2 to the tape and make multiple turns to fix the cutting wire 2 to the tape.

[0068] A main roller 1 and an auxiliary roller 3 are connected by a transmission device 4, so that the main roller 1 can drive the auxiliary roller 3 to rotate, and the auxiliary roller 3 rotates synchronously with the main roller 1, thereby enabling multiple main roller 1s and multiple auxiliary roller 3s to rotate synchronously; in some feasible embodiments, the transmission device 4 is a transmission shaft, which can be connected to the main roller 1 and the auxiliary roller 3 respectively by a buckle or a bolt;

[0069] The initial wiring of the cutting line 2 and the auxiliary line 4 is performed manually. The cutting line 2 is pushed into the first groove of the main roller 1 using a handle. After determining the position of the first cutting line 2, the subsequent multiple cutting lines 2 are moved closer to the first cutting line 2 in sequence. After the initial wiring width is reached, the initial wiring of the cutting line 2 is completed. In some feasible embodiments, the initial width of the cutting line 2 is 3-6mm.

[0070] Similarly, using the handle for wiring, the auxiliary line 4 is pushed into the first groove of the auxiliary roller 3. After determining the position of the first auxiliary line 4, the subsequent auxiliary lines 4 are sequentially moved closer to the first auxiliary line 4. After reaching the initial wiring width, the initial wiring of the auxiliary line 4 is completed. In some feasible embodiments, the initial width of the auxiliary line 4 is 3-6mm.

[0071] After the initial wiring, the cutting line 2 in the initial wiring area on the main roller 1 and the auxiliary line 4 in the initial wiring area on the auxiliary roller 3 are fixed respectively. The fixing method is to use fasteners to fix the cutting line 2 and the auxiliary line 4 in the initial wiring area respectively, so that the cutting line 2 on the main roller 1 and the auxiliary line 4 on the auxiliary roller 3 are not easy to come apart. The fastener is preferably tape, which will not damage the cutting line 2 and the auxiliary line 4. After the cutting line 2 in the initial wiring area of ​​the roller and the auxiliary line 4 in the initial wiring area of ​​the auxiliary roller 3 are fixed, the connector of the cutting line 2 to the end of the main roller 1 is disconnected and the connector of the end of the main roller 1 is removed. The end of the cutting line 2 is tidied up. At the same time, the connector of the auxiliary line 4 to the end of the auxiliary roller 3 is disconnected and the connector of the end of the auxiliary roller 3 is removed. The end of the auxiliary line 4 is tidied up.

[0072] Automatic wiring is performed using machines, based on the cutting process.

[0073] After the automatic wiring is completed, the connection between the main roller 1 and the auxiliary roller 3 is disconnected, and the monocrystalline silicon rod 6 is cut. The transmission device 4 is disconnected from the main roller 1 and the auxiliary roller 3 respectively, so that the multiple main rollers 1 in the cutting roller group rotate, and the multiple auxiliary rollers 3 in the auxiliary roller group rotate. The cutting roller group and the auxiliary roller group operate separately to cut the monocrystalline silicon rod 6.

[0074] During the cutting of the monocrystalline silicon rod 6, as the feed position increases, the feed speed, cutting line speed and coolant flow rate are set during the cutting stage to cut the monocrystalline silicon rod 6; during the lifting stage, the feed speed and coolant flow rate are set to lift the material.

[0075] During the cutting stage, the cutting line speed is 35-45m / s. This cutting line speed is selected according to actual needs, and no specific requirements are specified here.

[0076] The coolant flow rate is 240-270L / min. This coolant flow rate should be selected according to actual needs, and no specific requirements are specified here.

[0077] The feed rate is 2-2.5 mm / min. This feed rate should be selected according to actual needs, and no specific requirements are specified here.

[0078] During the feeding stage, the feed speed is 20-55 mm / min. This feed speed can be selected according to actual needs, and no specific requirements are specified here.

[0079] The coolant flow rate is 200-240L / min. This coolant flow rate can be selected according to actual needs, and no specific requirements are given here.

[0080] Specifically, during the cutting stage, as the feed position increases, the feed rate parameter value, cutting line speed parameter value, and coolant flow rate parameter value at each feed position are shown in the table below:

[0081]

[0082] During the dicing stage, when the existing dicing system (which only has a dicing wire mesh and no auxiliary wire mesh) is used to dice the single crystal silicon rod 6, the feed rate parameter value, dicing line speed parameter value, and coolant flow rate parameter value at each feed position are shown in the table below as the feed position increases:

[0083]

[0084]

[0085] Analysis of the two process parameter tables above shows that, due to the presence of the auxiliary roller group and the auxiliary wire mesh, the cutting line speed increases and the coolant flow rate decreases when cutting the single crystal silicon rod 6.

[0086] During the feeding stage, as the feed position decreases, the feed rate parameter value, cutting line speed parameter value, and coolant flow rate parameter value at each feed position are shown in the table below:

[0087]

[0088] During the material feeding stage, when using the existing cutting system (which only has a cutting wire mesh and no auxiliary wire mesh) for material feeding, the feed rate parameter value, cutting line speed parameter value, and coolant flow rate parameter value at each feed position are shown in the table below as the number of feed positions decreases:

[0089]

[0090]

[0091] Analysis of the two tables above shows that during the feeding stage, the auxiliary roller 3 and auxiliary wire mesh create longer gaps between silicon wafers 7, facilitating the spraying of coolant into the gaps between the silicon wafers 7 and thus increasing the feeding speed.

[0092] Due to the adoption of the above technical solution, an auxiliary roller assembly is provided. This auxiliary roller assembly is set within the space formed by the cutting roller assembly and the cutting mesh. An auxiliary mesh is provided on the auxiliary roller assembly, located on the side of the cutting mesh away from the monocrystalline silicon rod. The auxiliary mesh is set parallel to the cutting mesh, and the layout specifications of the auxiliary lines in the auxiliary mesh are consistent with the layout specifications of the cutting lines in the cutting mesh. Each auxiliary line in the auxiliary mesh corresponds one-to-one with each cutting line in the cutting mesh, and there is a certain distance between the auxiliary mesh and the cutting mesh. When the cutting mesh cuts the monocrystalline silicon rod, each auxiliary line in the auxiliary mesh is located a certain distance below the corresponding cutting line. The auxiliary lines separate two adjacent silicon wafers, so that there is a certain gap below the cut point of the silicon wafer during the cutting process, which increases the penetration depth of the coolant, improves the chip removal capacity of the coolant, and reduces the wear of the cutting lines.

[0093] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A silicon rod cutting system, comprising a cutting roller assembly equipped with a cutting wire mesh, characterized in that: It also includes an auxiliary roller assembly with an auxiliary wire mesh. The auxiliary roller assembly is located in the space formed by the cutting wire mesh and the cutting roller assembly. The auxiliary wire mesh is located on the side of the cutting wire mesh away from the single crystal silicon rod. There is a distance between the auxiliary wire mesh and the cutting wire mesh, and the layout specifications of the auxiliary wire mesh are consistent with the layout specifications of the cutting wire mesh, so that there is a certain gap between any cutting line in the cutting wire mesh and the auxiliary line corresponding to that cutting line to allow the flow of coolant. The auxiliary roller group includes at least two auxiliary rollers. One of the auxiliary rollers in the auxiliary roller group is connected to a drive device, or one of the auxiliary rollers in the auxiliary roller group is connected to a main cutting roller in the cutting roller group through a transmission device. The auxiliary rollers rotate to perform the feeding and taking-up of the auxiliary wire mesh. In the vertical direction of the cutting wire mesh, the distance between the axis of the auxiliary roller and the cutting wire mesh is not less than the wire bow value of the cutting wire mesh.

2. The silicon rod cutting system according to claim 1, characterized in that: The cutting area of ​​the cutting wire mesh is arranged parallel to the segmentation area of ​​the auxiliary wire mesh. In the direction perpendicular to the cutting wire mesh, multiple cutting lines in the cutting area of ​​the cutting wire mesh correspond one-to-one with multiple auxiliary lines in the segmentation area of ​​the auxiliary wire mesh.

3. The silicon rod cutting system according to claim 1 or 2, characterized in that: The cutting roller assembly includes at least two main cutting rollers, and two auxiliary rollers are disposed between the two main cutting rollers. The diameter of the auxiliary rollers is smaller than the diameter of the main cutting rollers.

4. The silicon rod cutting system according to claim 1, characterized in that: The distance between the auxiliary wire mesh and the cutting wire mesh is no greater than a first distance, which is 5-10mm.

5. The silicon rod cutting system according to claim 4, characterized in that: The distance between adjacent auxiliary rollers and main cutting rollers is a second distance, which is 100-110mm.

6. The silicon rod cutting system according to any one of claims 1-5, characterized in that: The diameter of the auxiliary lines constituting the auxiliary mesh is not greater than the diameter of the cutting lines constituting the cutting mesh.

7. A silicon rod cutting process, characterized in that: The method of cutting a single crystal silicon rod using the silicon rod cutting system as described in any one of claims 1-6 includes the following steps: A main cutting roller shaft in the cutting roller shaft group is connected to an auxiliary roller shaft in the auxiliary roller shaft group. The main cutting roller shaft drives the auxiliary roller shaft to rotate, thereby performing the initial wiring of the cutting wire mesh and the initial wiring of the auxiliary wire mesh respectively. After the initial wiring is completed, the cutting lines in the initial wiring area on the main cutting roller and the auxiliary lines in the initial wiring area on the auxiliary roller are fixed respectively. Perform automatic wiring; After automatic wiring, the connection between the main cutting roller and the auxiliary roller is disconnected to cut the monocrystalline silicon rod; In the process of cutting monocrystalline silicon rods, during the cutting stage, the feed speed, cutting line speed, and coolant flow rate are set as the feed position increases; during the lifting stage, the feed speed and coolant flow rate are set as the feed position decreases.

8. The silicon rod cutting process according to claim 7, characterized in that: When a main cutting roller in a cutting roller group is connected to an auxiliary roller in an auxiliary roller group, the connection includes: The auxiliary rollers in the auxiliary roller group are connected by connectors, so that multiple auxiliary rollers rotate synchronously. Fix the ends of the auxiliary line by wrapping the auxiliary line around the connector. The main cutting rollers in the cutting roller assembly are connected by the connector, so that multiple main cutting rollers rotate synchronously. Fix the end of the cutting line by wrapping the cutting line around the connector. One of the main cutting roller shafts and one of the auxiliary roller shafts are connected by a transmission device, so that the main cutting roller shaft can drive the auxiliary roller shaft to rotate.

9. The silicon rod cutting process according to claim 7 or 8, characterized in that: When performing the initial routing of the cut net and the initial routing of the auxiliary net, respectively, it includes: The initial wiring of the cutting line and the initial wiring of the auxiliary line are carried out manually. The initial wiring width of the cutting line is 3-6mm, and the initial wiring width of the auxiliary line is 3-6mm.

10. The silicon rod cutting process according to claim 9, characterized in that: During the cutting stage, the cutting line speed is 35-45 m / s, the coolant flow rate is 240-270 L / min, and the feed rate is 2-2.5 mm / min.

11. The silicon rod cutting process according to claim 10, characterized in that: During the feeding stage, the feeding speed is 20-55 mm / min, and the coolant flow rate is 200-240 L / min.

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