Method for cutting silicon wafers and use thereof

Abstract

The present application relates to the technical field of silicon wafer production, in particular to a cutting method of silicon wafer and application thereof. The method comprises: (a) transferring new wire to a take-up wheel, paying out the new wire on the take-up wheel to perform first knife reverse cutting, and recycling primary old wire to a pay-off wheel; (b) paying out the primary old wire on the pay-off wheel to perform first knife forward cutting, and recycling secondary old wire to the take-up wheel; (c) transferring the primary old wire stored on the pay-off wheel to the take-up wheel, transferring the new wire stored on the pay-off wheel to the take-up wheel, paying out the new wire and the primary old wire on the take-up wheel to perform second knife reverse cutting, and recycling the tertiary old wire obtained by the second knife reverse cutting to the pay-off wheel; and (d) paying out the tertiary old wire on the pay-off wheel to perform second knife forward cutting, and recycling quaternary old wire to the take-up wheel. The method has the advantages of low wire consumption, small old wire surplus amount of the pay-off wheel, high production efficiency, short wire transfer time, etc.

Description

Technical Field

[0001] This invention relates to the field of silicon wafer manufacturing technology, and more specifically, to a method for cutting silicon wafers and its application. Background Technology

[0002] The cutting of silicon wafers involves steel wire being released from the feed reel, passing through the left feed reel, left tension reel, and left guide reel to the left and right main rollers of the cutting shaft, where it is wound and spread out, and then passing through the right guide reel, right tension reel, and right feed reel to the take-up reel; then it undergoes a high-speed reciprocating bidirectional motion.

[0003] Currently, the 191.6mm silicon wafers are cut using a two-stage (reverse + forward) cutting mode, with 15km of new wire used per cut and 13km of wire transferred during the turnaround. This involves transferring the 15km of unused new wire stored on the pay-off reel to the take-up reel before the first cut. During the cutting process, the first cut releases the 15km of new wire from the take-up reel, while the old wire, after being cut by abrasive debris, is wound back onto the pay-off reel. The second cut involves further cutting the 15km of old wire on the pay-off reel, and then winding back 7.7km onto the take-up reel. After the first cut, 7.3km of old wire remains on the pay-off reel, 7km on the main roller wire mesh, and 7.7km on the take-up reel. Before the second cut, the remaining 7.3km of old wire on the pay-off reel is transferred to the take-up reel, and simultaneously, the 13km of new wire used in this cut is transferred to the take-up reel before the (reverse + forward) two-stage cutting begins. The cutting process parameters are set as follows:

[0004] Table 1

[0005]

[0006]

[0007] Existing cutting methods have the following drawbacks:

[0008] ①Long changeover time and low production efficiency:

[0009] Before each cut, the 7.3km of steel wire to be used in this cut needs to be transferred to the take-up reel. This process causes wear on the steel wire during the running process, resulting in a loss of cutting force. On the other hand, it prolongs the time for changing the die with a single blade, reducing production efficiency.

[0010] ② High wire loss:

[0011] Currently, the single-blade line consumption is 13km, and the single-chip line consumption is 3.31m / p.

[0012] In view of this, the present invention is hereby proposed. Summary of the Invention

[0013] The purpose of this invention is to provide a silicon wafer cutting method and its application. The silicon wafer cutting method has the advantages of low wire consumption, small amount of old wire residue after the wire feeding wheel is cut, high production efficiency, and short wire transfer time.

[0014] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0015] One aspect of the present invention relates to a method for dicing a silicon wafer, comprising the following steps:

[0016] (a) Transfer the new line stored on the pay-off reel to the take-up reel, release the new line on the take-up reel for a first reverse cut, and recycle the old line obtained from the first reverse cut back to the pay-off reel;

[0017] (b) The old thread on the feed reel is released and cut in the first forward direction, and the old thread obtained by the first forward cut is recycled back to the take-up reel;

[0018] (c) Transfer the old primary wire stored on the pay-off reel to the take-up reel, transfer the new wire stored on the pay-off reel to the take-up reel, release the new wire and the old primary wire on the take-up reel for a second reverse cut, and recycle the old tertiary wire obtained from the second reverse cut back to the pay-off reel;

[0019] (d) The old wire from the three times on the feed reel is released and then cut in the second forward direction. The old wire obtained from the second forward cut is then retrieved onto the take-up reel.

[0020] The silicon wafer cutting method described above has advantages such as low wire consumption, minimal residual amount of old wire after cutting by the wire feeding wheel, high production efficiency, and short turnaround time.

[0021] Another aspect of the present invention relates to a method for preparing a solar cell, including the method for cutting the silicon wafer.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] (1) The silicon wafer cutting method provided by the present invention, by reasonably setting process parameters according to the actual wear of the steel wire, makes reasonable use of new and old wires, reduces the time spent on wire transfer, improves production efficiency, and increases the utilization rate of steel wires, thereby achieving the effects of reducing the amount of old wire left over from the wire feeding wheel, reducing wire consumption, and saving costs.

[0024] (2) The silicon wafer cutting method provided by the present invention can reduce the wire consumption per blade to 10km and the wire consumption per wafer to 2.53m / p. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 The location of the silicon rod cutting process equipment provided in the embodiments of the present invention. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0028] One aspect of the present invention relates to a method for dicing a silicon wafer, comprising the following steps:

[0029] (a) Transfer the new line stored on the pay-off reel to the take-up reel, release the new line on the take-up reel for a first reverse cut, and recycle the old line obtained from the first reverse cut back to the pay-off reel;

[0030] (b) The old thread on the feed reel is released and cut in the first forward direction, and the old thread obtained by the first forward cut is recycled back to the take-up reel;

[0031] (c) Transfer the old primary wire stored on the pay-off reel to the take-up reel, transfer the new wire stored on the pay-off reel to the take-up reel, release the new wire and the old primary wire on the take-up reel for a second reverse cut, and recycle the old tertiary wire obtained from the second reverse cut back to the pay-off reel;

[0032] (d) The old wire from the three times on the feed reel is released and then cut in the second forward direction. The old wire obtained from the second forward cut is then retrieved onto the take-up reel.

[0033] The silicon wafer cutting method described above, by rationally setting process parameters based on the actual wear of the steel wire, makes reasonable use of new and old wires, reduces the time spent on wire transfer, improves production efficiency, and increases the utilization rate of steel wire. This achieves the effects of reducing the amount of old wire left over from the wire feeding wheel, reducing wire consumption, and saving costs. The wire consumption per cut can be reduced to 10km, and the wire consumption per wafer is 2.53m / p.

[0034] Further, in step (a), the length of the new line transferred to the take-up reel is 13 to 15 km, including but not limited to a point value of any one of 13 km, 13.5 km, 14 km, 14.5 km or 15 km or a range between any two.

[0035] Further, in step (a), the length of the old line obtained by the first reverse cut is 13 to 15 km, including but not limited to the point value of any one of 13 km, 13.5 km, 14 km, 14.5 km or 15 km or the range value between any two.

[0036] During the first reverse cut, the take-up reel releases 13-15km of new line. After the first reverse cut is completed, 13-15km of old line is obtained and retrieved onto the pay-off reel for later use.

[0037] Further, in step (b), the length of the old line released from the reel is 7 to 9 km, including but not limited to any one of 7 km, 7.5 km, 8 km, 8.5 km or 9 km or any range between two of them.

[0038] Further, in step (b), the length of the secondary old line obtained by the first cut in the forward direction is 7 to 9 km, including but not limited to the point value of any one of 7 km, 7.5 km, 8 km, 8.5 km or 9 km or the range value between any two.

[0039] During the first forward cut, 7-9 km of old wire stored on the feed reel is released, and then the obtained secondary old wire is recycled back to the take-up reel, thereby improving the utilization rate of old wire.

[0040] Furthermore, the depth of the reverse cut of the first blade is 190 to 192 mm, including but not limited to a point value or a range between any two of 190 mm, 190.5 mm, 191 mm, 191.5 mm or 192 mm.

[0041] Furthermore, the depth of the first blade's forward cut is 200.2-200.7 mm, including but not limited to a point value or a range between any two of 200.2 mm, 200.3 mm, 200.4 mm, 200.5 mm, 200.6 mm, or 200.7 mm.

[0042] Further, in step (c), the length of the new line transferred to the take-up reel is 10 to 12 km, including but not limited to a point value of any one of 10 km, 10.5 km, 11 km, 11.5 km or 12 km or a range between any two.

[0043] Further, in step (c), the length of the old line released by the second reverse cut is 1 to 3 km, including but not limited to the point value of any one of 1 km, 1.5 km, 2 km, 2.5 km or 3 km or the range value between any two.

[0044] Further, in step (c), the length of the three old lines obtained by the second reverse cut is 11 to 15 km, including but not limited to the point value of any one of 11 km, 13 km, 13.5 km, 14 km, 14.5 km or 15 km or the range value between any two.

[0045] When performing the second reverse cut, the length of the new thread released by the take-up reel and the length of the old thread are controlled to meet the thread requirements for the second reverse cut. This can improve the utilization rate of the old thread, reduce the amount of new thread used, and save cutting costs.

[0046] Further, in step (d), the length of the three old lines released from the reel is 7 to 9 km, including but not limited to any one of 7 km, 7.5 km, 8 km, 8.5 km or 9 km or any range between two of them.

[0047] Further, in step (d), the length of the four old lines obtained by the second forward cut is 7 to 9 km, including but not limited to the point value of any one of 7 km, 7.5 km, 8 km, 8.5 km or 9 km or the range value between any two.

[0048] When making the second forward cut, the old thread from the third cut is released to meet the amount of thread required for the second forward cut, and the old thread from the fourth cut is stored on the take-up reel, which can improve the utilization rate of the old thread.

[0049] Furthermore, the depth of the second blade's reverse cut is 190-192 mm, including but not limited to a point value or a range between any two of 190 mm, 190.5 mm, 191 mm, 191.5 mm, or 192 mm.

[0050] Furthermore, the depth of the second blade's forward cut is 200.2 to 200.7 mm, including but not limited to a point value or a range between any two of 200.2 mm, 200.3 mm, 200.4 mm, 200.5 mm, 200.6 mm, or 200.7 mm.

[0051] The steps for each subsequent cut are the same as those for the second cut; simply repeat steps (c) and (d). The parameters applicable to the second cut also apply to the subsequent cuts.

[0052] Furthermore, the cutting parameters for the first reverse cut are as follows:

[0053] When the silicon ingot feed position is -1 to 0 mm, the linear speed is 500 to 750 m / min (e.g., 500 m / min, 550 m / min, 600 m / min, 650 m / min, 700 m / min, or 750 m / min), and the stage speed is 1200 to 1500 μm / min (e.g., 1200 μm / min, 1250 μm / min, 1300 μm / min, 1350 μm / min, 140 μm / min). 0μm / min, 1450μm / min or 1500μm / min), feed rate of 700-750m (e.g. 700m, 710m, 720m, 730m, 740m or 750m), return rate of 700-730m (e.g. 700m, 710m, 720m or 730m), flow rate of 210-220L / min (e.g. 210L / min, 215L / min or 220L / min);

[0054] When the silicon rod is fed to a position of 3-5 mm, the linear speed is 1000-1200 m / min (e.g., 1000 m / min, 1050 m / min, 1100 m / min, 1150 m / min or 1200 m / min), the table speed is 1700-1800 μm / min (e.g., 1700 μm / min, 1730 μm / min, 1750 μm / min, 1780 μm / min or 1800 μm / min), the wire feed is 700-725 m (e.g., 700 m, 705 m, 710 m, 715 m, 720 m or 725 m), the wire return is 650-685 m (e.g., 650 m, 660 m, 670 m, 680 m or 685 m), and the flow rate is 220 L / min.

[0055] When the silicon ingot is fed to a position of 8–10 mm, the linear speed is 1700–1800 m / min (e.g., 1700 m / min, 1730 m / min, 1750 m / min, 1780 m / min, or 1800 m / min), and the stage speed is 2100–2200 μm / min (e.g., 2100 μm / min, 2130 μm / min, 2150 μm / min, 2180 μm / min, or 2200 μm / min). The flow rate is 650-698m (e.g., 650m, 660m, 670m, 680m, 690m or 698m), the return flow rate is 600-642m (e.g., 600m, 610m, 620m, 630m or 642m), and the flow rate is 210-220L / min (e.g., 210L / min, 213L / min, 215L / min, 218L / min or 220L / min).

[0056] When the silicon ingot is fed to a position of 13–15 mm, the linear speed is 2000–2100 m / min (e.g., 2000 m / min, 2030 m / min, 2050 m / min, 2080 m / min, or 2100 m / min), and the stage speed is 2500–2600 μm / min (e.g., 2500 μm / min, 2530 μm / min, 2550 μm / min, 2580 μm / min, or 2600 μm / min). The feed rate is 600–662 m (e.g., 600 m, 610 m, 620 m, 630 m, 640 m, 650 m or 662 m), the return rate is 550–588 m (e.g., 550 m, 560 m, 570 m or 588 m), and the flow rate is 210–220 L / min (e.g., 210 L / min, 213 L / min, 215 L / min, 218 L / min or 220 L / min).

[0057] When the silicon ingot feed position is 19–20 mm, the linear speed is 2000–2100 m / min (e.g., 2000 m / min, 2030 m / min, 2050 m / min, 2080 m / min, or 2100 m / min), the stage speed is 2700–2800 μm / min (e.g., 2700 μm / min, 2730 μm / min, 2750 μm / min, 2780 μm / min, or 2800 μm / min), and the wire feed rate is 6. 00~667m (e.g. 600m, 610m, 620m, 630m, 640m, 650m or 667m), loop length is 500~583m (e.g. 500m, 510m, 520m, 530m, 540m, 550m, 560m, 570m or 583m), flow rate is 210~220L / min (e.g. 210L / min, 213L / min, 215L / min, 218L / min or 220L / min);

[0058] When the silicon ingot feed position is 55–60 mm, the linear speed is 2000–2100 m / min (e.g., 2000 m / min, 2030 m / min, 2050 m / min, 2080 m / min, or 2100 m / min), the table speed is 2700–2800 μm / min (e.g., 2700 μm / min, 2730 μm / min, 2750 μm / min, 2780 μm / min, or 2800 μm / min), and the wire feed rate is 6. 00~672m (e.g. 600m, 610m, 620m, 630m, 640m, 650m, 660m or 672m), loop length is 500~578m (e.g. 500m, 510m, 520m, 530m, 540m, 550m, 560m or 578m), flow rate is 210~220L / min (e.g. 210L / min, 213L / min, 215L / min, 218L / min or 220L / min);

[0059] When the silicon ingot feed position is 85–90 mm, the linear speed is 2000–2100 m / min (e.g., 2000 m / min, 2030 m / min, 2050 m / min, 2080 m / min, or 2100 m / min), the table speed is 2700–2800 μm / min (e.g., 2700 μm / min, 2730 μm / min, 2750 μm / min, 2780 μm / min, or 2800 μm / min), and the wire feed rate is… 600–681m (e.g., 600m, 610m, 620m, 630m, 640m, 650m, 660m, 670m or 681m), loop length of 500–569m (e.g., 500m, 510m, 520m, 530m, 540m, 550m or 569m), flow rate of 210–220L / min (e.g., 210L / min, 213L / min, 215L / min, 218L / min or 220L / min);

[0060] When the silicon ingot is fed to a position of 105–110 mm, the linear speed is 2000–2100 m / min (e.g., 2000 m / min, 2030 m / min, 2050 m / min, 2080 m / min, or 2100 m / min), and the stage speed is 2600–2700 μm / min (e.g., 2600 μm / min, 2630 μm / min, 2650 μm / min, 2680 μm / min, or 270 μm / min). 0 μm / min), feed rate is 600-690m (e.g., 600m, 630m, 650m, 670m or 690m), return rate is 500-560m (e.g., 500m, 520m, 540m or 560m), flow rate is 210-220L / min (e.g., 210L / min, 212L / min, 214L / min, 216L / min, 218L / min or 220L / min);

[0061] When the silicon ingot is fed to a position of 125–130 mm, the linear speed is 2000–2100 m / min (e.g., 2000 m / min, 2030 m / min, 2050 m / min, 2080 m / min, or 2100 m / min), and the stage speed is 2500–2600 μm / min (e.g., 2500 μm / min, 2530 μm / min, 2550 μm / min, 2580 μm / min, or 2600 μm / min). The feed line length is 650-700m (e.g., 650m, 660m, 670m, 680m, 690m or 700m), the return line length is 500-550m (e.g., 500m, 510m, 520m, 530m, 540m or 550m), and the flow rate is 210-220L / min (e.g., 210L / min, 212L / min, 214L / min, 216L / min, 218L / min or 220L / min);

[0062] When the silicon ingot is fed to a position of 145–150 mm, the linear speed is 2000–2100 m / min (e.g., 2000 m / min, 2030 m / min, 2050 m / min, 2080 m / min, or 2100 m / min), and the stage speed is 2300–2400 μm / min (e.g., 2300 μm / min, 2330 μm / min, 2350 μm / min, 2380 μm / min, or 2400 μm / min). The cable length is 650–709m (e.g., 650m, 660m, 670m, 680m, 690m or 709m), the return cable length is 500–541m (e.g., 500m, 510m, 520m, 530m or 541m), and the flow rate is 210–220L / min (e.g., 210L / min, 212L / min, 214L / min, 216L / min, 218L / min or 220L / min);

[0063] When the silicon ingot is fed to a position of 165–170 mm, the linear speed is 2000–2100 m / min (e.g., 2000 m / min, 2030 m / min, 2050 m / min, 2080 m / min, or 2100 m / min), and the stage speed is 2100–2200 μm / min (e.g., 2100 μm / min, 2130 μm / min, 2150 μm / min, 2180 μm / min, or 2200 μm / min). Line length is 650–718m (e.g., 650m, 660m, 670m, 680m, 690m, 700m or 718m), loop length is 480–532m (e.g., 480m, 490m, 500m, 510m, 520m or 532m), and flow rate is 210–220L / min (e.g., 210L / min, 212L / min, 214L / min, 216L / min, 218L / min or 220L / min);

[0064] When the silicon ingot feed position is 175–180 mm, the linear speed is 2000–2100 m / min (e.g., 2000 m / min, 2030 m / min, 2050 m / min, 2080 m / min, or 2100 m / min), the table speed is 1900–2000 μm / min (e.g., 1900 μm / min, 1930 μm / min, 1950 μm / min, 1980 μm / min, or 2000 μm / min), and the wire feed rate is 650– 723m (e.g., 650m, 660m, 670m, 680m, 690m, 700m, 710m or 723m), return line length is 450-527m (e.g., 450m, 460m, 470m, 480m, 490m, 500m, 510m or 527m), flow rate is 210-220L / min (e.g., 210L / min, 212L / min, 214L / min, 216L / min, 218L / min or 220L / min);

[0065] When the silicon ingot feed position is 180–185 mm, the linear speed is 2000–2100 m / min (e.g., 2000 m / min, 2030 m / min, 2050 m / min, 2080 m / min, or 2100 m / min), the table speed is 1700–1800 μm / min (e.g., 1700 μm / min, 1730 μm / min, 1750 μm / min, 1780 μm / min, or 1800 μm / min), and the wire feed rate is 650– 728m (e.g., 650m, 660m, 670m, 680m, 690m, 700m, 710m or 728m), loop length of 450-522m (e.g., 450m, 460m, 470m, 480m, 490m, 500m, 510m or 522m), flow rate of 210-220L / min (e.g., 210L / min, 212L / min, 214L / min, 216L / min, 218L / min or 220L / min);

[0066] When the silicon ingot is fed to a position of 188–190 mm, the linear speed is 2000–2100 m / min (e.g., 2000 m / min, 2030 m / min, 2050 m / min, 2080 m / min, or 2100 m / min), and the stage speed is 1400–1500 μm / min (e.g., 1400 μm / min, 1430 μm / min, 1450 μm / min, 1480 μm / min, or...). 1500μm / min), feed line length is 700-732m (e.g., 700m, 710m, 720m or 732m), return line length is 500-518m (e.g., 500m, 505m, 510m or 518m), flow rate is 210-220L / min (e.g., 210L / min, 212L / min, 214L / min, 216L / min, 218L / min or 220L / min);

[0067] When the silicon ingot is fed to a position of 190–192 mm, the linear speed is 2000–2100 m / min (e.g., 2000 m / min, 2030 m / min, 2050 m / min, 2080 m / min, or 2100 m / min), and the stage speed is 1100–1200 μm / min (e.g., 1100 μm / min, 1130 μm / min, 1150 μm / min, 1180 μm / min, or 1200 μm / min). The feed rate is 750–773 m (e.g., 750 m, 755 m, 760 m, 765 m or 773 m), the return rate is 1050–1102 m (e.g., 1050 m, 1060 m, 1070 m, 1090 m or 1102 m), and the flow rate is 180–200 L / min (e.g., 180 L / min, 185 L / min, 190 L / min, 195 L / min or 200 L / min).

[0068] The reverse cutting parameters for the second cut and each subsequent cut are the same as those for the first reverse cutting.

[0069] Furthermore, the cutting parameters for the first blade's forward cutting are as follows:

[0070] When the silicon ingot is fed to a position of 192–194 mm, the linear speed is 1600–1700 m / min (e.g., 1600 m / min, 1630 m / min, 1650 m / min, 1680 m / min, or 1700 m / min), and the stage speed is 800–900 μm / min (e.g., 800 μm / min, 820 μm / min, 840 μm / min, 860 μm / min, 880 μm / min, or 900 μm / min). The feed line is 700-744m (e.g., 700m, 710m, 720m, 730m or 744m), the return line is 1300-1356m (e.g., 1300m, 1310m, 1320m, 1330m, 1340m or 1356m), and the flow rate is 180-200L / min (e.g., 180L / min, 185L / min, 190L / min, 195L / min or 200L / min).

[0071] When the silicon ingot is fed to a position of 195–197 mm, the linear speed is 1500–1600 m / min (e.g., 1500 m / min, 1530 m / min, 1550 m / min, 1580 m / min, or 1600 m / min), and the stage speed is 500–600 μm / min (e.g., 500 μm / min, 520 μm / min, 540 μm / min, 560 μm / min, 580 μm / min, or 600 μm / min). The feed line is 750-797m (e.g., 750m, 760m, 770m, 780m or 797m), the return line is 1400-1453m (e.g., 1400m, 1410m, 1420m, 1430m, 1440m or 1453m), and the flow rate is 180-200L / min (e.g., 180L / min, 185L / min, 190L / min, 195L / min or 200L / min).

[0072] When the silicon ingot is fed to a position of 197–199 mm, the linear speed is 1400–1500 m / min (e.g., 1400 m / min, 1430 m / min, 1450 m / min, 1480 m / min, or 1500 m / min), and the stage speed is 250–300 μm / min (e.g., 250 μm / min, 260 μm / min, 270 μm / min, 280 μm / min, 290 μm / min, or 300 μm / min). The cable length is 900–928m (e.g., 900m, 905m, 910m, 915m, 920m or 928m), the return cable length is 1300–1322m (e.g., 1300m, 1305m, 1310m, 1315m, 1320m or 1322m), and the flow rate is 180–200L / min (e.g., 180L / min, 185L / min, 190L / min, 195L / min or 200L / min);

[0073] When the silicon ingot feed position is 198–200 mm, the linear speed is 1400–1450 m / min (e.g., 1400 m / min, 1410 m / min, 1420 m / min, 1430 m / min, or 1450 m / min), the table speed is 150–180 μm / min (e.g., 150 μm / min, 160 μm / min, 170 μm / min, or 180 μm / min), and the wire feed rate is 90. 0–928m (e.g., 900m, 905m, 910m, 915m, 920m or 928m), loop length 1300–1322m (e.g., 1300m, 1305m, 1310m, 1315m, 1320m or 1322m), flow rate 180–200L / min (e.g., 180L / min, 185L / min, 190L / min, 195L / min or 200L / min);

[0074] When the silicon ingot is fed to a position of 200.2–200.7 mm, the linear speed is 1400–1450 m / min (e.g., 1400 m / min, 1410 m / min, 1420 m / min, 1430 m / min, or 1450 m / min), the table speed is 50–80 μm / min (e.g., 50 μm / min, 60 μm / min, 70 μm / min, or 80 μm / min), and the wire feed rate is 800. ~850m (e.g. 800m, 810m, 820m, 830m, 840m or 850m), return line length of 1500~1550m (e.g. 1500m, 1510m, 1520m, 1530m, 1540m or 1550m), flow rate of 180~200L / min (e.g. 180L / min, 185L / min, 190L / min, 195L / min or 200L / min).

[0075] The forward cutting parameters for the second cut and each subsequent cut are the same as those for the first cut.

[0076] To complement the innovative cutting method, improve cutting efficiency, and reduce wire consumption, this invention adjusts and improves the cutting parameters for reverse and forward cutting. The cutting parameters are adjusted according to the change in the feed position of the silicon rod.

[0077] The new thread mentioned in this invention refers to an unused cutting thread.

[0078] The feeding position of the silicon rod mentioned in this invention is defined as the position where the silicon rod contacts the main roller wire mesh, with downward feeding being positive and upward feeding being negative.

[0079] Another aspect of the present invention relates to a method for preparing a solar cell, including the method for cutting the silicon wafer.

[0080] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0081] Example 1

[0082] This embodiment employs a two-stage cutting mode (reverse + forward) with 13km of wire used per cutter and 10km of wire transferred. The 10km is the wire usage required to successfully cut a single 191.6mm silicon material under current cutting conditions, and it meets the wire consumption limit design of this scheme. The 13km of unused new wire stored on the feed reel is transferred to the take-up reel before the first cut begins (i.e., the feed reel releases 20km of new wire, 7km is laid on the wire mesh of the left and right main rollers of the cutting shaft, and the take-up reel receives the remaining 13km). During the cutting process... The first stage of cutting involves releasing 13km of new wire from the take-up reel, while the old wire, after being cut by abrasive particles, is wound back onto the feed reel and cut to a processing depth of 192mm. The second stage releases 7km of the 13km old wire from the feed reel, and the second old wire, after being cut again by abrasive particles, is wound back onto the take-up reel and cut to a processing depth of 200.7mm before the process ends. After cutting, 6km of old wire remains on the feed reel, 7km of old wire remains on the main roller wire mesh, and 7km of old wire remains on the take-up reel. The equipment locations for the silicon rod cutting process are as follows: Figure 1 As shown.

[0083] Before the second cut, the 6km of old wire remaining on the pay-off reel is transferred to the take-up reel, and simultaneously the 10km of new wire used in this cut is transferred to the take-up reel. Then, the two-stage cutting (reverse + forward) begins, and other cuts follow the same procedure. The second cut begins with two-stage cutting (reverse + forward). In the first stage, 13km of wire (the 10km of new wire from the second cut plus the 3km of old wire used in the first cut) is released from the take-up reel. The old wire, after being cut by abrasive chips, is wound back onto the pay-off reel and cut to a process depth of 192mm. In the second stage, 7km of the 13km of old wire is released from the pay-off reel. The old wire, after being cut by abrasive chips again, is wound back onto the take-up reel and cut to a process depth of 200.7mm before the movement ends. After the cutting is completed, 6km of old wire remains on the pay-off reel, 7km of old wire remains on the main roller wire mesh, and 7km of old wire remains on the take-up reel.

[0084] The third cut is performed in the same manner as the second cut.

[0085] The cutting process parameter settings are shown in Table 2.

[0086] Table 2

[0087]

[0088]

[0089] In Table 2, steps 1-15 (including step 15) refer to the first segment of the two-segment cutting mode - designing 15 matching stage position cutting parameters according to the downward feed position of the silicon rod; steps 15-20 (excluding step 15) refer to the second segment of the two-segment cutting mode - designing 5 matching stage position cutting parameters according to the downward feed position of the silicon rod; the overall wire cutting process of the above cutting scheme is completed by using the stage position cutting parameters.

[0090] In this embodiment, the single-blade line consumption is 10km, and the single-chip line consumption is 2.53m / p.

[0091] A roll of brand-new steel wire is typically 180km long. The first cut requires 7km of new wire from the main roller wiring mesh, and the reverse cut requires 13km of new wire, totaling 20km. The remaining 160km of new wire is used for subsequent cuts, each of which requires 10km of new wire + 3km of old wire. Under normal circumstances, the 160km of new wire is used for 16 cuts, totaling 180km of new wire, which can cut silicon material 17 times. A single silicon rod is 780mm long, and the main roller groove pitch is 0.18mm. After cutting: the theoretical number of wafers = length of single silicon rod / main roller groove pitch, that is, the theoretical number of wafers = 780mm / 0.18mm ≈ 4333 wafers. Based on a yield rate of 96.5%, the number of wafers is approximately 4181. 17 cuts total approximately 71088 wafers. The wire consumption per wafer = 180km of new wire / total theoretical number of wafers = 180000m / 71088p ≈ 2.53m / p.

[0092] Example 2

[0093] The only difference between this embodiment and Embodiment 1 is that during the first cut, the first cut releases 15km of new line from the take-up reel; the second cut releases 9km of the 15km of old line from the pay-off reel; and during the second cut, the first cut transfers 12km of new line to the take-up reel, and the second cut releases 9km of the 15km of old line from the pay-off reel.

[0094] In this embodiment, the single-blade line consumption is 12km, and the single-chip line consumption is 3.00m / p.

[0095] Example 3

[0096] The only difference between this embodiment and Embodiment 1 is that during the first cut, the first cut releases 14km of new line from the take-up reel; the second cut releases 8km of the 14km of old line from the pay-off reel; and during the second cut, the first cut transfers 11km of new line to the take-up reel, and the second cut releases 8km of the 14km of old line from the pay-off reel.

[0097] In this embodiment, the single-blade line consumption is 11km, and the single-chip line consumption is 2.77m / p.

[0098] Although the present invention has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and scope of the present invention; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such substitutions and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A method for cutting a silicon wafer, characterized in that, Includes the following steps: (a) Transfer the new line stored on the pay-off reel to the take-up reel, release the new line on the take-up reel for a first reverse cut, and recycle the old line obtained from the first reverse cut back to the pay-off reel; (b) The old thread on the feed reel is released and cut in the first forward direction, and the old thread obtained by the first forward cut is recycled back to the take-up reel; (c) Transfer the old primary wire remaining on the pay-off reel to the take-up reel, transfer the new wire stored on the pay-off reel to the take-up reel, release the new wire and the old primary wire on the take-up reel for a second reverse cut, and recycle the old tertiary wire obtained from the second reverse cut back to the pay-off reel; (d) The old wire from the three times on the pay-off reel is released and then cut in the second forward direction. The old wire obtained from the second forward cut is then retrieved onto the take-up reel. In step (a), the length of the new line transferred to the take-up reel is 13-15 km; In step (a), the length of the old line obtained by the first reverse cut is 13~15km; Step (b) involves releasing a length of 7-9 km of old wire from the reel. In step (b), the length of the secondary old line obtained by the first forward cut is 7~9km; Step (c), the length of the new line transferred to the take-up reel is 10~12km; Step (c) involves performing the second reverse cut to release the length of the old line, which is 1-3 km. In step (c), the length of the old line obtained by the second reverse cut is 11~15km; Step (d) involves releasing a length of 7-9 km of the old wire from the reel. In step (d), the length of the old line obtained by the second forward cut is 7~9km.

2. The silicon wafer cutting method according to claim 1, characterized in that, The first cut reaches a depth of 190-192 mm in the reverse direction; And / or, the depth of the first cutter in the forward direction is 200.2~200.7 mm.

3. The silicon wafer cutting method according to claim 1, characterized in that, The second cut is made to a depth of 190-192 mm in the reverse direction; And / or, the depth of the second cut in the forward direction is 200.2~200.7mm.

4. The silicon wafer cutting method according to claim 1, characterized in that, The cutting parameters for the first reverse cut are as follows: When the silicon rod feed position is -1~0mm, the linear speed is 500~750m / min, the table speed is 1200~1500μm / min, the wire feed is 700~750m, the return wire is 700~730m, and the flow rate is 210~220L / min. When the silicon rod feed position is 3~5mm, the linear speed is 1000~1200m / min, the table speed is 1700~1800μm / min, the wire feed is 700~725m, the return wire is 650~685m, and the flow rate is 220L / min. When the silicon rod feed position is 8~10mm, the linear speed is 1700~1800m / min, the table speed is 2100~2200μm / min, the wire feed is 650~698m, the return wire is 600~642m, and the flow rate is 210~220L / min. When the silicon rod feed position is 13~15mm, the linear speed is 2000~2100 m / min, the table speed is 2500~2600μm / min, the wire feed is 600~662m, the return wire is 550~588m, and the flow rate is 210~220L / min. When the silicon rod feed position is 19~20mm, the linear speed is 2000~2100m / min, the table speed is 2700~2800μm / min, the wire feed is 600~667m, the return wire is 500~583m, and the flow rate is 210~220L / min. When the silicon rod feed position is 55~60mm, the linear speed is 2000~2100m / min, the table speed is 2700~2800μm / min, the wire feed is 600~672m, the return wire is 500~578m, and the flow rate is 210~220L / min. When the silicon rod is fed to a position of 85~90mm, the linear speed is 2000~2100m / min, the table speed is 2700~2800μm / min, the wire feed is 600~681m, the return wire is 500~569m, and the flow rate is 210~220L / min. When the silicon rod feed position is 105~110mm, the linear speed is 2000~2100m / min, the table speed is 2600~2700μm / min, the wire feed is 600~690m, the return wire is 500~560m, and the flow rate is 210~220L / min. When the silicon rod is fed to a position of 125~130mm, the linear speed is 2000~2100m / min, the table speed is 2500~2600μm / min, the wire feed is 650~700m, the return wire is 500~550m, and the flow rate is 210~220L / min. When the silicon rod feed position is 145~150mm, the linear speed is 2000~2100m / min, the table speed is 2300~2400μm / min, the wire feed is 650~709m, the return wire is 500~541m, and the flow rate is 210~220L / min. When the silicon rod feed position is 165~170mm, the linear speed is 2000~2100m / min, the table speed is 2100~2200μm / min, the wire feed is 650~718m, the return wire is 480~532m, and the flow rate is 210~220L / min. When the silicon rod feed position is 175~180mm, the linear speed is 2000~2100m / min, the table speed is 1900~2000μm / min, the wire feed is 650~723m, the return wire is 450~527m, and the flow rate is 210~220L / min. When the silicon rod feed position is 180~185mm, the linear speed is 2000~2100m / min, the table speed is 1700~1800μm / min, the wire feed is 650~728m, the return wire is 450~522m, and the flow rate is 210~220L / min. When the silicon rod is fed to a position of 188~190mm, the linear speed is 2000~2100m / min, the table speed is 1400~1500μm / min, the wire feed is 700~732m, the return wire is 500~518m, and the flow rate is 210~220L / min. When the silicon rod feed position is 190~192mm, the linear speed is 2000~2100m / min, the table speed is 1100~1200μm / min, the wire feed is 750~773m, the return wire is 1050~1102m, and the flow rate is 180~200L / min.

5. The silicon wafer cutting method according to claim 1, characterized in that, The cutting parameters for the first forward cut are as follows: When the silicon rod feed position is 192~194mm, the linear speed is 1600~1700m / min, the table speed is 800~900μm / min, the wire feed is 700~744m, the return wire is 1300~1356m, and the flow rate is 180~200L / min. When the silicon rod feed position is 195~197mm, the linear speed is 1500~1600m / min, the table speed is 500~600μm / min, the wire feed is 750~797m, the return wire is 1400~1453m, and the flow rate is 180~200L / min. When the silicon rod feed position is 197~199mm, the linear speed is 1400~1500m / min, the table speed is 250~300μm / min, the wire feed is 900~928m, the return wire is 1300~1322m, and the flow rate is 180~200L / min. When the silicon rod feed position is 198~200mm, the linear speed is 1400~1450m / min, the table speed is 150~180μm / min, the wire feed is 900~928m, the return wire is 1300~1322m, and the flow rate is 180~200L / min. When the silicon rod is fed to a position of 200.2~200.7mm, the linear speed is 1400~1450m / min, the table speed is 50~80μm / min, the wire feed is 800~850m, the return wire is 1500~1550m, and the flow rate is 180~200L / min.

6. A method for preparing a solar cell, characterized in that, The method for cutting silicon wafers includes any one of claims 1 to 5.

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