Silicon rod cutting system and cutting process

Abstract

The silicon rod cutting system comprises a cutting roller shaft set provided with a cutting wire net and an auxiliary roller shaft set provided with an auxiliary wire net, the auxiliary roller shaft set is arranged in a space formed by the cutting wire net and the cutting roller shaft set, and the auxiliary wire net is arranged on the side face, away from a silicon single crystal rod, of the cutting wire net. A distance is formed 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 formed between any cutting wire in the cutting wire net and the auxiliary wire corresponding to the cutting wire, and cooling liquid flows. The cutting line has the beneficial effects that the auxiliary line separates the two adjacent silicon wafers, so that a certain gap is formed below the cutting position of the silicon wafers in the cutting process, the entering depth of cooling liquid is increased, the chip removal capacity of the cooling liquid is improved, the abrasion condition of the cutting line is reduced, the entering depth of the cooling liquid is increased, and the chip removal capacity of the cooling liquid is improved; and the abrasion condition of the cutting line is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of silicon wafer cutting, and in particular relates to a silicon rod cutting system and a cutting process. Background Art

[0002] In the existing silicon wafer cutting field, as the thinning process advances, the cutting line of the silicon wafer is getting thinner and thinner. During the cutting process, the interval between adjacent silicon wafers becomes smaller, and they are more likely to be adsorbed together. It is difficult for the coolant to be brought into the cutting line to participate in the cutting, which leads to wire breakage during the cutting process and greater TTV and color difference of the cut silicon wafer.

[0003] In order to improve the problem of poor tangent liquid carrying capacity caused by the thinning process, the current solution is to increase the coolant flow and pressure and adopt a forward and reverse tangent process, with liquid at both ends of the in-line cutting and return-line cutting to increase the penetration depth of the coolant during the slicing process; however, this method increases the penetration depth of the coolant at both ends of the cut silicon wafer. When cutting the middle part of the silicon rod, the amount of coolant is still insufficient, resulting in a large color difference between the middle part 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 a cutting process to solve the above or other problems existing in the prior art.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a silicon rod cutting system, including a cutting roller group provided with a cutting wire mesh, and also including an auxiliary roller group provided with an auxiliary wire mesh, the auxiliary roller group is arranged in a space constructed by the cutting wire mesh and the cutting roller group, the auxiliary wire mesh is arranged on a 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 the cutting line, so that the coolant can flow.

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

[0007] Furthermore, the auxiliary roller set includes at least two auxiliary rollers, the cutting roller set includes at least two main cutting rollers, the two auxiliary rollers are arranged 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 web, the distance between the axis of the auxiliary roller and the cutting wire web is not less than the wire bow value of the cutting wire web.

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

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

[0011] Furthermore, the wire diameters of the auxiliary wires constituting the auxiliary wire mesh are not greater than the wire diameters of the cutting wires constituting the cutting wire mesh.

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

[0013] A silicon rod cutting process, using the silicon rod cutting system as described above to cut a single crystal silicon rod, comprises the following steps:

[0014] A main cutting roller in the cutting roller group is connected to an auxiliary roller in the auxiliary roller group, and the main cutting roller drives the auxiliary roller to rotate, respectively performing initial wiring of the cutting wire net and initial wiring of the auxiliary wire net;

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

[0016] Perform automatic wiring;

[0017] After automatic routing, disconnect the main cutting roller and the auxiliary roller to cut the single crystal silicon rod;

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

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

[0020] The auxiliary rollers in the auxiliary roller group are connected by a connecting piece so that the multiple auxiliary rollers rotate synchronously;

[0021] Fix the end of the auxiliary line and wrap the auxiliary line around the connector;

[0022] The main cutting rollers in the cutting roller group are connected by a connecting piece so that the multiple main cutting rollers rotate synchronously;

[0023] Fix the end of the cutting line and wind the cutting line around the connecting piece;

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

[0025] Furthermore, when performing the initial wiring of the cutting wire net and the initial wiring of the auxiliary wire net respectively, 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 3-6 mm, and the initial width of the auxiliary line is 3-6 mm.

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

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

[0029] Due to the adoption of the above technical scheme, an auxiliary roller group is provided, and the auxiliary roller group is arranged in the space formed by the cutting roller group and the cutting mesh wire. An auxiliary wire mesh is arranged on the auxiliary roller group, and the auxiliary wire mesh is located on the side of the cutting wire mesh away from the single crystal silicon rod. The auxiliary wire mesh is arranged in parallel with the cutting wire mesh. The layout specifications of the auxiliary wires in the auxiliary wire mesh are consistent with the layout specifications of the cutting wires in the cutting wire mesh. Each auxiliary wire in the auxiliary wire mesh corresponds to each cutting wire in the cutting wire mesh one by one, and there is a certain distance between the auxiliary wire mesh and the cutting wire mesh. When the cutting wire mesh cuts the single crystal silicon rod, each auxiliary wire in the auxiliary wire mesh is located at a certain distance below the corresponding cutting line. The auxiliary wire separates two adjacent silicon wafers, so that during the cutting process, there is a certain gap below the cutting point of the silicon wafer, which increases the entry depth of the coolant, improves the chip removal capacity of the coolant, reduces the wear of the cutting wire, increases the entry depth of the coolant, improves the chip removal capacity of the coolant, and reduces the wear of the cutting wire. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0034] In the figure:

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

[0036] 4. Auxiliary line 5. Transmission device 6. Monocrystalline silicon rod

[0037] 7. Silicon wafer DETAILED DESCRIPTION

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

[0039] Figure 1 A structural schematic diagram of an embodiment of the present invention is shown. The present embodiment relates to a silicon rod cutting system and a cutting process for cutting single crystal silicon rods. The silicon rod cutting system has an auxiliary roller group provided 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, so that during the cutting process, the gap below the cutting line at the silicon wafer cutting location is increased, the entry depth of the coolant is increased, the chip removal capacity of the coolant is improved, the wear of the cutting line is reduced, the TTV of the silicon wafer is reduced, the color difference is reduced, and the silicon wafer cutting quality is improved.

[0040] A silicon rod cutting system, such as Figure 1 and 2 As shown, it includes a cutting roller group provided with a cutting wire net, and the cutting wire 2 is wound on the cutting roller group to form a cutting wire net, and the cutting wire net is used to cut the single crystal silicon rod 6; it also includes an auxiliary roller group provided with an auxiliary wire net, and the auxiliary roller group is arranged in a space formed by the cutting wire net and the cutting roller group, and the auxiliary wire net is arranged on a side of the cutting wire net away from the single crystal silicon rod 6, that is, the auxiliary wire net is arranged below the cutting wire net, and the layout specifications of the auxiliary wire net are consistent with the layout specifications of the cutting wire net, and the cutting wire net cuts the single crystal silicon rod 6, and after cutting, a A plurality of silicon wafers 7, the auxiliary lines 4 constituting the auxiliary line network are located between two adjacent silicon wafers 7, separating the two adjacent silicon wafers 7. The setting of the auxiliary line network extends the length of the gap below the cutting line 2 between the adjacent silicon wafers 7, so that a flow channel is formed below the cutting line 2 where the silicon wafer 7 is cut, where the adjacent silicon wafers 7 are not in contact, and the coolant can flow along the flow channel, thereby increasing the penetration depth of the coolant, improving the chip removal capacity of the coolant, reducing the wear of the tangent line, reducing the TTV of the silicon wafer 7, reducing the color difference, and improving the cutting quality of the silicon wafer 7.

[0041] Specifically, Figure 1 and 2As shown, the cutting roller group includes at least two main rollers 1 and a cutting wire net. The main roller 1 is a groove wheel structure. A plurality of wire grooves are arranged on the main roller 1 so that the cutting wire 2 is wound around each main roller 1. Along the axial direction of the main roller 1, the cutting wire 2 is wound in each wire groove in turn. The cutting wire 2 is located in the wire groove to construct a cutting wire net structure. Since the single crystal silicon rod 6 has a certain width and thickness, in order to facilitate the cutting of the single crystal silicon rod 6 by the cutting wire net, along the horizontal direction, there is a certain distance between two adjacent main rollers 1, and the distance is greater than the width of the single crystal silicon rod 6. Along the vertical direction, there is a certain distance between two adjacent main rollers 1, and the distance is greater than the thickness of the single crystal silicon rod 6, so that during the cutting process, each main roller 1 will not interfere with the feeding movement of the single crystal silicon rod 6. Moreover, the cutting line 2 is wound on multiple main rollers 1, and the wire mesh area formed by the cutting line 2 between two horizontally arranged main rollers 1 cuts the monocrystalline silicon rod 6. The two main rollers 1 are set as main cutting rollers. The distance between the two main cutting rollers can be 400-420mm, and the diameter of the main cutting roller can be 160-180mm. The distance between the two main cutting rollers and the diameter of the main cutting roller are selected according to actual needs, and no specific requirements are made here.

[0042] The two main cutting rollers, the other main rollers 1 for winding the auxiliary cutting wires 2, and the cutting wire net form a receiving space. During the cutting process of the single crystal silicon rod 6, the silicon wafer 7 formed by the cut single crystal silicon rod 6 gradually enters the receiving space. The auxiliary roller group is arranged in the receiving space. The auxiliary wire net on the auxiliary roller group is located on the inner side (below) of the cutting wire net. The auxiliary wire net has a segmentation area corresponding to the cutting area of ​​the cutting wire net. The segmentation area is arranged below the cutting area of ​​the cutting wire net. When the single crystal silicon rod 6 is cut in the cutting area of ​​the cutting wire net, each auxiliary wire 4 in the segmentation area of ​​the auxiliary wire net is respectively located at any Between two adjacent silicon wafers 7, the two adjacent silicon wafers 7 are separated. Since the auxiliary line 4 is located below the cutting line 2, the setting of the auxiliary line 4 can reduce the adsorption length of the adjacent silicon wafers 7 and extend the length of the gap below the cutting line 2, so that during the cutting process of the single crystal silicon rod 6, there is a gap of a certain length at a certain distance from the cutting line 2 at the cutting point of the silicon wafer 7. The distance is greater than the gap length below the cutting line 2 when no auxiliary line network is set in the prior art. Therefore, the existence of the gap and the increase in the gap length can increase the entry depth of the coolant, improve the chip removal ability of the coolant, and reduce the wear of the cutting line 2.

[0043] Therefore, when the auxiliary wire network is set up, the layout specifications of the auxiliary wire network are consistent with the layout specifications of the cutting wire network. The multiple cutting wires 2 in the cutting area of ​​the cutting wire network correspond to the multiple auxiliary wires 4 in the segmentation area of ​​the auxiliary wire network. There is an auxiliary wire 4 below each cutting wire 2. Since the single crystal silicon rod 6 is fed in the vertical direction during the cutting process, the corresponding group of cutting wires 2 and the auxiliary wires 4 are located in the same plane in the vertical direction. Therefore, the multiple cutting wires 2 in the cutting area of ​​the cutting wire network correspond to the multiple auxiliary wires 4 in the segmentation area of ​​the corresponding auxiliary wire network. The auxiliary lines 4 form a plurality of parallel planes arranged along the vertical direction, and a group of cutting lines 2 and auxiliary lines 4 are arranged in each plane. The cutting lines 2 in each plane cut the single crystal silicon rod 6. The auxiliary lines 4 are located below the cutting lines 2 to separate the silicon wafers 7 adsorbed together after cutting, and increase the length of the gap below the cutting lines 2 at the cutting position. In view of the width of the single crystal silicon rod 6, the gap forms a flow channel in the width direction of the single crystal silicon rod 6, and the coolant can flow in the flow channel, so that the entry depth of the coolant is increased so that the coolant can participate in the cutting.

[0044] In the above structure, the number of auxiliary lines 4 in the segmentation area of ​​the auxiliary wire mesh is consistent with the number of cutting lines 2 in the cutting area of ​​the cutting wire mesh. Of course, the number of auxiliary lines 4 in the segmentation area of ​​the auxiliary wire mesh is different from the number of cutting lines 2 in the cutting area of ​​the cutting wire mesh, and the number of auxiliary lines 4 in the segmentation area of ​​the auxiliary wire mesh is less than the number of cutting lines 2 in the cutting area of ​​the cutting wire mesh. However, in this structure, each auxiliary line 4 corresponds to a cutting line 2, and each auxiliary line 4 is located below a cutting line 2, forming multiple groups of cutting lines 2 and auxiliary lines 4, so as to cut the single crystal silicon rod 6 and separate adjacent silicon wafers 7. The number of auxiliary lines 4 in the segmentation area of ​​the auxiliary wire mesh is selected according to actual needs.

[0045] In order to avoid interference between the cutting wire mesh and the auxiliary wire mesh during the cutting process of the single crystal silicon rod 6, there is a certain distance between the auxiliary wire mesh and the cutting wire mesh, and the distance between the auxiliary wire mesh and the cutting wire mesh is not greater than the first distance, the first distance is 5-10mm, and the first distance is selected according to actual needs, and no specific requirements are made here. The distance between the auxiliary wire mesh and the cutting wire mesh is set to ensure that there is a certain length of gap below the cutting line 2 at the cutting position, thereby increasing the penetration depth of the coolant.

[0046] The above-mentioned auxiliary roller group includes at least two auxiliary rollers 3, and the auxiliary wire 4 is wound on multiple auxiliary rollers 3 to form an auxiliary wire net. The auxiliary roller 3 is a groove wheel, and multiple wire grooves are arranged along the axial direction of the auxiliary roller 3. In order to achieve the consistency between the layout specifications of the auxiliary wire net and the layout specifications of the cutting wire net, the shape and number of the wire grooves on the auxiliary roller 3 are consistent with the shape and number of the wire grooves on the main cutting roller, so that the cutting wire 2 wound on the main roller 1 is arranged in the same manner as the auxiliary wire 4 wound on the auxiliary roller 3, and the gap between adjacent cutting wires 2 is consistent with the gap between adjacent auxiliary wires 4, so that the multiple cutting wires 2 in the cutting area of ​​the cutting wire net correspond one-to-one with the multiple auxiliary wires 4 in the dividing area of ​​the auxiliary wire net.

[0047] In order 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 12-18 mm. The diameter of the auxiliary roller 3 is selected according to actual needs and no specific requirements are made here.

[0048] There are at least two auxiliary rollers 3 in the auxiliary roller group. The number of auxiliary rollers 3 is selected according to actual needs and no specific requirements are made here. Different numbers of auxiliary rollers 3 are set in different ways. When there are two auxiliary rollers 3, the two auxiliary rollers 3 are set horizontally, and the plane where the two auxiliary rollers 3 are located is parallel to the plane where the two main cutting rollers are located, and the distance between the two auxiliary rollers 3 is smaller than the distance between the two main cutting rollers. The auxiliary wires 4 are wound around the two auxiliary rollers 3, and auxiliary wire nets are formed on the upper and lower sides of the two auxiliary rollers 3, respectively. The multiple auxiliary wires 4 in the auxiliary wire net on the upper side correspond to the multiple auxiliary wires 4 in the auxiliary wire net on the lower side. At the same time, the multiple auxiliary wires 4 in the auxiliary wire net on the upper side correspond to the multiple cutting wires 2 of the cutting wire net on the two main cutting rollers, so that the cutting wires 2 cut the single crystal silicon rods 6 and the auxiliary wires 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 100-110 mm. The second distance is selected according to actual needs and no specific requirements are given here. The second distance is set to avoid 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 255-275 mm. 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. The number of auxiliary rollers 3 in one group is at least two. The multiple auxiliary rollers 3 in the group are grouped in pairs. The multiple groups of auxiliary rollers 3 are arranged in sequence along the vertical direction (perpendicular to the direction of the cutting wire web), and the two auxiliary rollers 3 in each group are arranged along the horizontal direction, so that the auxiliary wire web wound on the multiple groups of auxiliary rollers 3 is arranged parallel to the cutting wire web. When multiple groups of auxiliary rollers 3 are winding auxiliary wires 4, there can be one auxiliary wire 4, which is wound on each group of auxiliary rollers 3 in turn, and auxiliary wire network segmentation areas are formed on the group of auxiliary rollers 3 closest to the cutting wire network and the group of auxiliary rollers 3 farthest from the cutting wire network, respectively, to separate the cut silicon wafers 7; or, there are multiple auxiliary wires 4, and the number of auxiliary wires 4 is consistent with the number of groups of auxiliary rollers 3, each auxiliary wire 4 is wound on a group of auxiliary rollers 3, and an auxiliary wire network is formed on each group of auxiliary rollers 3, and there are multiple auxiliary wire networks along the vertical direction, and the multiple auxiliary wires 4 in the segmentation areas of the multiple auxiliary wire networks correspond one to one; the winding method of the auxiliary wires 4 on multiple groups of auxiliary rollers 3 can also be other settings, which can be selected according to actual needs, and no specific requirements are made here.

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

[0053] In order to prevent the auxiliary wire network from damaging the adjacent silicon wafer 7 after cutting, the wire diameter of the auxiliary wire 4 constituting the auxiliary wire network is not larger than the wire diameter of the cutting wire 2 constituting the cutting wire network. The wire diameter of the auxiliary wire 4 is selected according to actual needs and no specific requirements are made here.

[0054] In order to avoid interference between the cutting wire mesh and the auxiliary wire mesh during the cutting process of the single crystal silicon rod 6, in the vertical direction of the cutting wire mesh, the distance between the axis of the auxiliary roller 3 and the cutting wire mesh is not less than the wire bow value of the cutting wire mesh. Figure 3 and Figure 4 It can be known that the calculation formula of line bow is:

[0055]

[0056] Where w is the line bow value, V f is the feed speed, V c is the linear velocity, l i is the width of the single crystal, l w is the sheave spacing, dw is the wire diameter, F0 is the breaking tension of cutting wire 2, K p is the Preston coefficient, and t is the cutting time.

[0057] It can be known from the above-mentioned calculation formula of the wire bow that the wire bow gradually changes with time and finally stabilizes at a value. During the cutting process of the single crystal silicon rod 6, the wire bow value of the cutting wire mesh is maintained 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 not less than the wire bow value of the cutting wire 2 of the cutting wire mesh, so that the auxiliary roller 3 is not affected by the wire bow of the cutting wire mesh.

[0058] In the auxiliary roller group, any of the auxiliary rollers 3 is connected to a driving device, which drives the auxiliary roller 3 to rotate. Through the auxiliary wire net, the auxiliary roller 3 can drive other auxiliary rollers 3 to rotate, so as to achieve the feeding and winding of the auxiliary wire net, that is, the auxiliary roller 3 connected to the driving device is an active roller. Of course, the auxiliary rollers 3 in the auxiliary roller group are not connected to a driving device. Any auxiliary roller 3 in the auxiliary roller group is connected to the active roller of the two main cutting rollers through the transmission device 5. The auxiliary roller 3 is driven to rotate by the rotation of the main cutting roller, so that the main roller 1 and the auxiliary roller 3 rotate synchronously.

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

[0060] In this embodiment, the number of auxiliary rollers 3 in the auxiliary roller group is two, and 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 15 mm, and the diameter of the main cutting roller is 170 mm. The distance between the two main cutting rollers is 400 mm, and the distance between the two auxiliary rollers 3 is 255 mm. The distance between each auxiliary roller 3 and the adjacent main cutting roller is 105 mm. The auxiliary wire 4 is wound on the two auxiliary rollers 3, and is wound in sequence along the axial direction of the auxiliary rollers 3 to form an auxiliary wire net, and a dividing area is formed on the upper and lower sides of the two auxiliary rollers 3 respectively; the cutting roller group includes two main cutting rollers and one main roller, and the main roller is located below the two main cutting rollers. The cutting wire 2 is wound on the two main cutting rollers and the main roller 2 to form a cutting wire net, and a cutting area of ​​the cutting wire net is formed on the upper side of the two main cutting rollers. The cutting area of ​​the cutting wire net corresponds to the dividing area of ​​the auxiliary wire net and is arranged in parallel, and the multiple cutting wires 2 in the cutting area correspond to the multiple auxiliary wires 4 in the dividing area. When the two auxiliary rollers 3 are set and installed, the wire bow value of the cutting wire net on the two main cutting rollers is calculated according to the calculation formula of the wire bow value, and the vertical distance between the axis of the auxiliary roller 3 and the cutting wire 2 net is set according to the wire bow value to prevent the auxiliary roller 3 from being affected by the cutting wire net.

[0061] When cutting the single crystal silicon rod 6, the single crystal silicon rod 6 moves toward the cutting wire mesh and is fed. The cutting wire 2 in the cutting area of ​​the cutting wire mesh cuts the single crystal silicon rod 6 and cuts the single crystal silicon rod 6 into multiple silicon wafers 7. As the single crystal silicon rod 6 is fed, each auxiliary wire 4 in the segmentation area 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 wire 2 and the auxiliary wire 4 below the cutting wire 2, the auxiliary wire 4 separates the two adjacent silicon wafers 7, so that there is a certain gap between the auxiliary wire 4 below the cutting wire 2. When the number of auxiliary wires 4 is multiple, the gap below the cutting wire 2 is further increased. The cutting wire 2, the auxiliary wire 4 and the two adjacent silicon wafers 7 can constitute a circulation channel. During the cutting process, the coolant can flow in the circulation channel. The circulation channel is formed below each cutting wire 2, which increases the entry depth of the coolant, improves the chip removal capacity of the coolant, reduces the wear of the cutting wire, reduces the TTV of the silicon wafer 7, reduces the color difference, and improves the cutting quality of the silicon wafer 7.

[0062] A silicon rod cutting process, using the above-mentioned silicon rod cutting system to cut the single crystal silicon rod 6, comprises the following steps:

[0063] A main roller 1 in the cutting roller group is connected to an auxiliary roller 3 in the auxiliary roller group, and the main roller 1 drives the auxiliary roller 3 to rotate, and the initial wiring of the cutting wire net and the initial wiring of the auxiliary wire net are performed respectively; this step includes:

[0064] The multiple auxiliary rollers 3 in the auxiliary roller group are connected by a connecting piece, so that the multiple auxiliary rollers 3 rotate synchronously; in some feasible embodiments, the connecting piece is preferably an adhesive tape, and the adhesive tape is used to wrap multiple circles around the head positions of the multiple auxiliary rollers 3 to connect the multiple auxiliary rollers 3 together, so that the multiple auxiliary rollers 3 rotate synchronously;

[0065] Fix the end of the auxiliary wire 4, pull out an auxiliary wire 4 from the pay-off shaft, and fix the auxiliary wire 4 on the connecting piece so that the auxiliary wire 4 can be wound on the auxiliary roller 3 later; when the connecting piece is a tape, stick the auxiliary wire 4 on the tape, and wind it for multiple turns to fix the auxiliary wire 4 on the tape;

[0066] The multiple main rollers 1 in the cutting roller group are connected by a connecting piece, so that the multiple main rollers 1 rotate synchronously; in some feasible embodiments, the connecting piece is preferably an adhesive tape, which will not cause damage to the main roller 1 and the auxiliary roller 3. The adhesive tape is used to wrap multiple circles around the head positions of the multiple main rollers 1 to connect the multiple main rollers 1 together, so that the multiple main rollers 1 rotate synchronously;

[0067] The end of the cutting line 2 is fixed, a cutting line 2 is drawn out from the pay-off shaft, the cutting line 2 is passed through the tension pulley block, the cutting line 2 is tightened, and the cutting line 2 is fixedly wound on the connecting member so that the cutting line 2 can be wound on the main roller shaft 1 later; when the connecting member is a tape, the cutting line 2 is adhered to the tape and wound multiple times to fix the cutting line 2 on the tape;

[0068] A main roller shaft 1 is connected to an auxiliary roller shaft 3 through a transmission device 4, so that the main roller shaft 1 can drive the auxiliary roller shaft 3 to rotate, so that the auxiliary roller shaft 3 rotates synchronously with the main roller shaft 1, and then multiple main roller shafts 1 and multiple auxiliary roller shafts 3 rotate synchronously; in some feasible embodiments, the transmission device 4 is a transmission shaft, and the transmission shaft can be connected to the main roller shaft 1 and the auxiliary roller shaft 3 respectively through buckles or bolts;

[0069] The initial routing of the cutting line 2 and the auxiliary line 4 is performed manually; the cutting line 2 is routed into the first wire groove of the main roller shaft 1 using a handle, and after the position of the first cutting line 2 is determined, the subsequent cutting lines 2 are moved closer to the first cutting line 2 in sequence, and the initial routing of the cutting line 2 is completed after the initial routing width is reached; in some feasible embodiments, the initial width of the cutting line 2 is 3-6 mm;

[0070] Similarly, the auxiliary wire 4 is inserted into the first wire groove of the auxiliary roller shaft 3 using the handle for wiring. After the position of the first auxiliary wire 4 is determined, the following multiple auxiliary wires 4 are brought closer to the first auxiliary wire 4 in sequence. After the initial wiring width is reached, the initial wiring of the auxiliary wire 4 is completed. In some feasible embodiments, the initial width of the auxiliary wire 4 is 3-6 mm.

[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 a fixing piece 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 spread out. The fixing piece is preferably an adhesive tape, which will not cause damage to 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 cutting line 2 is disconnected from the connecting piece at the end of the main roller 1, and the connecting piece at the end of the main roller 1 is removed, and the thread end of the cutting line 2 is arranged. At the same time, the auxiliary line 4 is disconnected from the connecting piece at the end of the auxiliary roller 3, and the connecting piece at the end of the auxiliary roller 3 is removed, and the thread end of the auxiliary line 4 is arranged;

[0072] Carry out automatic wiring, according to the cutting process, use the machine to carry out automatic wiring;

[0073] After the automatic wiring is completed, the connection between the main roller 1 and the auxiliary roller 3 is disconnected to cut the single crystal silicon rod 6, and 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 are rotated, and the multiple auxiliary rollers 3 in the auxiliary roller group are rotated, and the cutting roller group and the auxiliary roller group are operated separately to cut the single crystal silicon rod 6.

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

[0075] Among them, in the cutting stage, the cutting line speed is 35-45m / s. The cutting line speed is selected according to actual needs and no specific requirements are made here;

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

[0077] The feed speed is 2-2.5mm / min. The feed speed is selected according to actual needs and no specific requirements are made here.

[0078] In the material lifting stage, the feeding speed is 20-55mm / min. The feeding speed is selected according to actual needs and no specific requirements are given here;

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

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

[0081]

[0082] In the cutting stage, when the single crystal silicon rod 6 is cut by using the cutting system in the existing process (only with a cutting wire mesh, without an auxiliary wire mesh), as the feed position increases, the feed speed parameter value, the cutting wire speed parameter value and the coolant flow parameter value at each feed position are shown in the following table:

[0083]

[0084]

[0085] By analyzing the above two process parameter tables, it can be known that due to the existence of the auxiliary roller assembly and the auxiliary wire mesh, the cutting line speed is increased and the coolant flow rate is reduced when cutting the single crystal silicon rod 6.

[0086] In the feeding stage, as the feeding position decreases, the feeding speed parameter values, cutting line speed parameter values ​​and coolant flow parameter values ​​at each feeding position are shown in the following table:

[0087]

[0088] In the material lifting stage, when the cutting system in the existing process (only with cutting wire net, without auxiliary wire net) is used for material lifting, as the feed position decreases, the feed speed parameter value, cutting wire speed parameter value and coolant flow parameter value at each feed position are shown in the following table:

[0089]

[0090]

[0091] Through the analysis of the above two tables, it can be known that in the lifting stage, due to the setting of the auxiliary roller 3 and the auxiliary wire mesh, there are longer gaps between the silicon wafers 7, which facilitates the cooling liquid to spray into the gaps between the silicon wafers 7 during the lifting stage, thereby increasing the lifting speed.

[0092] Due to the adoption of the above technical scheme, an auxiliary roller group is provided, and the auxiliary roller group is arranged in the space formed by the cutting roller group and the cutting mesh wire. An auxiliary wire mesh is arranged on the auxiliary roller group, and the auxiliary wire mesh is located on the side of the cutting wire mesh away from the single crystal silicon rod. The auxiliary wire mesh is arranged in parallel with the cutting wire mesh. The layout specifications of the auxiliary wires in the auxiliary wire mesh are consistent with the layout specifications of the cutting wires in the cutting wire mesh. Each auxiliary wire in the auxiliary wire mesh corresponds to each cutting wire in the cutting wire mesh one by one, and there is a certain distance between the auxiliary wire mesh and the cutting wire mesh. When the cutting wire mesh cuts the single crystal silicon rod, each auxiliary wire in the auxiliary wire mesh is located at a certain distance below the corresponding cutting line. The auxiliary wire separates two adjacent silicon wafers, so that during the cutting process, there is a certain gap below the cutting point of the silicon wafer, which increases the entry depth of the coolant, improves the chip removal capacity of the coolant, reduces the wear of the cutting wire, increases the entry depth of the coolant, improves the chip removal capacity of the coolant, and reduces the wear of the cutting wire.

[0093] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A silicon rod cutting system, comprising a cutting roller assembly provided with a cutting wire mesh, characterized in that: It also includes an auxiliary roller group provided with an auxiliary wire mesh, wherein the auxiliary roller group is arranged in a space constructed by the cutting wire mesh and the cutting roller group, and the auxiliary wire mesh is arranged on a side of the cutting wire mesh away from the single crystal silicon rod, and 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 the cutting line, so that the cooling liquid can flow.

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

3. The silicon rod cutting system according to claim 1 or 2, characterized in that: The auxiliary roller group includes at least two auxiliary rollers, and the cutting roller group includes at least two main cutting rollers. The two auxiliary rollers are arranged between the two main cutting rollers, and 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 3, characterized in that: In the vertical direction of the cutting wire web, the distance between the axis of the auxiliary roller and the cutting wire web is not less than the wire bow value of the cutting wire web.

5. The silicon rod cutting system according to claim 4, characterized in that: The distance between the auxiliary wire mesh and the cutting wire mesh is not greater than a first distance, and the first distance is 5-10 mm.

6. The silicon rod cutting system according to claim 5, characterized in that: The distance between the adjacent auxiliary roller shafts and the main cutting roller shaft is a second distance, and the second distance is 100-110 mm.

7. The silicon rod cutting system according to any one of claims 4 to 6, characterized in that: The wire diameters of the auxiliary wires constituting the auxiliary wire mesh are not greater than the wire diameters of the cutting wires constituting the cutting wire mesh.

8. The silicon rod cutting system according to claim 3, characterized in that: One of the auxiliary rollers in the auxiliary roller group is connected to a driving device, or one of the auxiliary rollers in the auxiliary roller group is connected to a main cutting roller in the cutting roller group via a transmission device.

9. A silicon rod cutting process, characterized in that: The method of cutting a single crystal silicon rod using the silicon rod cutting system according to any one of claims 1 to 8 comprises the following steps: Connecting a main cutting roller in the cutting roller group with an auxiliary roller in the auxiliary roller group, wherein the main cutting roller drives the auxiliary roller to rotate, and respectively performs initial wiring of the cutting wire net and initial wiring of the auxiliary wire net; 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; Perform automatic wiring; After automatic wiring, disconnect the main cutting roller shaft from the auxiliary roller shaft to cut the single crystal silicon rod; In the process of cutting single crystal silicon, in the cutting stage, as the feed position increases, the feed speed, cutting line speed and coolant flow rate are set; in the lifting stage, as the feed position decreases, the feed speed and coolant flow rate are set.

10. The silicon rod cutting process according to claim 9, characterized in that: When a main cutting roller in a cutting roller group is connected to an auxiliary roller in an auxiliary roller group, it includes: The auxiliary rollers in the auxiliary roller group are connected by a connecting piece so that the plurality of auxiliary rollers rotate synchronously; Fixing the end of the auxiliary line by winding the auxiliary line around the connecting piece; The main cutting rollers in the cutting roller group are connected via the connecting member so that a plurality of the main cutting rollers rotate synchronously; Fixing the end of the cutting line by winding the cutting line around the connecting piece; A main cutting roller shaft is connected to an auxiliary roller shaft through a transmission device, so that the main cutting roller shaft can drive the auxiliary roller shaft to rotate.

11. The silicon rod cutting process according to claim 9 or 10, characterized in that: When performing the initial routing of the cutting wire net and the initial routing of the auxiliary wire net respectively, it includes: 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 3-6 mm, and the initial width of the auxiliary line is 3-6 mm.

12. The silicon rod cutting process according to claim 11, 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 speed is 2-2.5 mm / min.

13. The silicon rod cutting process according to claim 12, characterized in that: In 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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