Silicon wafer cutting method
Through the two-stage cutting process, the nickel layer of the diamond wire is first worn and then cut, which solves the problem of insufficient cutting capacity of single-crystal diamond electroplated diamond wire, improves the yield and yield of silicon wafers, and reduces processing costs.
Patent Information
- Application Number
- CN202411336165.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-24
- Publication Date
- 2024-12-27
AI Technical Summary
When cutting silicon wafers, the cutting capacity is not fully released due to the initial electroplating layer wrapping, resulting in high processing cost and low yield.
The two-stage cutting process is adopted, firstly the nickel layer of the diamond wire is worn through the first cutting process and treated with the edge. Then, the silicon wafer is cut using sharp diamond wires in the second cutting process to improve the cutting ability of the diamond wire.
By increasing the sharpness of the diamond wire, the cutting time is shortened, the yield and yield of silicon wafers are improved, and the processing cost of silicon wafers is reduced.
Smart Images
Figure CN119189080A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of silicon wafer processing, and in particular to a method for cutting a silicon wafer. Background Art
[0002] In the production process of solar silicon wafer cutting, the steel wire currently used in the industry to cut multicrystalline silicon wafers is mainly single-crystal diamond electroplated diamond wire. Compared with mortar wire cutting, the processing efficiency of diamond wire cutting multicrystalline is increased by about 40%, the cost is reduced by about 60%, etc., and the entire processing process is more environmentally friendly and efficient.
[0003] The advantages of diamond wire cutting multi-crystalline silicon wafers are mainly reflected in the reduction of silicon consumption per single wafer, the improvement of cutting efficiency and the improvement of silicon wafer parameters. With the gradual breakthrough of texturing technology such as black silicon texturing at the battery end, there is no technical barrier for diamond wire cutting of multi-crystalline silicon wafers.
[0004] However, for the current single crystal diamond electroplated diamond wire, after the diamond is pre-plated, the whole is wrapped with a layer of electroplating layer of a certain thickness. During the cutting process, since the diamond surface is initially wrapped with a certain thickness of electroplating layer, the cutting ability cannot be directly exerted in cutting silicon wafers. Only after a certain amount of silicon is cut can the diamond particles be gradually exposed to participate in cutting. Therefore, when the new wire mesh is cut, the silicon wafer entry position will have insufficient cutting ability due to the failure to release the cutting ability of the steel wire, resulting in high silicon wafer processing costs and low yields. Summary of the invention
[0005] The main purpose of the present invention is to provide a method for solving the problems of high silicon wafer processing cost and low yield in the prior art.
[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a method for cutting silicon wafers is provided, comprising: laying a diamond wire on one side of a first silicon rod, the diamond wire comprising a busbar and a nickel layer wrapping the busbar; cutting the first silicon rod by a first cutting process, wherein the nickel layer is separated from the busbar by the cutting process; removing the first silicon rod and laying a second silicon rod on one side of the diamond wire; and cutting the second silicon rod into silicon wafers by a second cutting process.
[0007] Optionally, in the second cutting process, the moving direction of the diamond wire is fixed.
[0008] Optionally, the wire feeding length in the above-mentioned second cutting process is 2000-5000m.
[0009] Optionally, the feed speed in the first cutting process is a first feed speed, the feed speed in the second cutting process is a second feed speed, and the first feed speed is less than the second feed speed.
[0010] Optionally, the first feeding speed is 100-1000 μm / min.
[0011] Optionally, the second feeding speed is 100-4500 μm / min.
[0012] Optionally, the linear speed in the first cutting process is a first linear speed, the linear speed in the second cutting process is a second linear speed, and the first linear speed is less than the second linear speed.
[0013] Optionally, the first linear speed is 800-1700 m / min.
[0014] Optionally, the second linear speed is 1300-2500 m / min.
[0015] Optionally, the cutting method further comprises: adding cutting fluid in the second cutting process.
[0016] By applying the technical solution of the present invention, a method for cutting silicon wafers is provided. After the diamond wire is arranged on one side of the first silicon rod, the first silicon rod can be cut by the first cutting process. Since the diamond wire will be worn during the cutting of the first silicon rod, and the diamond wire may include a busbar and a nickel layer wrapping the busbar, the nickel layer of the diamond wire can be first worn away in the first cutting process, that is, the nickel layer of the diamond wire can be separated from the busbar of the diamond wire by the first cutting process. At this time, the busbar of the diamond wire is not hindered by the nickel layer, and it can be considered that the diamond wire has been sharpened, thereby increasing the sharpness of the blade surface of the diamond wire, so that the cutting ability of the diamond wire is improved. Then, in the case of increasing the sharpness of the diamond wire, the first silicon rod can be lifted upward to remove the first silicon rod, and the second silicon rod can be arranged on one side of the diamond wire to achieve the purpose of cutting the second silicon rod into silicon wafers by the second cutting process. It can be understood that the diamond wire used in the first cutting process and the second cutting process remains unchanged, but the sharpness of the diamond wire in the second cutting process is greater than that of the diamond wire in the first cutting process. Therefore, compared with the cutting of the second silicon rod in the prior art, since the embodiment of the present application also includes the above-mentioned first cutting process before cutting the second silicon rod, the embodiment of the present application can take less time to cut the second silicon rod, and the quality of the silicon wafer after cutting can be better. Therefore, through the embodiment of the present application, the output and yield of silicon wafers can be greatly improved, and the silicon wafer processing cost can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:
[0018] Figure 1 A schematic flow chart of a silicon wafer cutting method according to an embodiment of the present invention is shown. DETAILED DESCRIPTION
[0019] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0020] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.
[0021] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0022] As described in the background technology, for the current diamond electroplated diamond wire, after the diamond is pre-plated, the whole is wrapped with a layer of electroplating layer of a certain thickness. During the cutting process, since the initial surface of the diamond is wrapped with a certain thickness of electroplating layer, the cutting ability cannot be directly exerted in cutting silicon wafers. Only after a certain amount of silicon is cut can the diamond particles be gradually exposed to participate in the cutting. Therefore, when the new wire mesh is cut, the silicon wafer entry position will have insufficient cutting ability due to the failure to release the cutting ability of the steel wire, resulting in high silicon wafer processing costs and low yields.
[0023] In order to solve the problem of high silicon wafer processing cost and low yield rate in the prior art, the embodiment of the present application provides a silicon wafer cutting method, such as Figure 1 As shown, including:
[0024] S1. Arranging a diamond wire on one side of a first silicon rod, wherein the diamond wire comprises a busbar and a nickel layer wrapping the busbar;
[0025] It is explained here that the diamond wire is a diamond electroplated cutting wire made by embedding tiny diamond particles on a cutting steel wire. Therefore, in addition to the above-mentioned mother bar and nickel layer, the diamond wire may also include diamond particles embedded on the above-mentioned mother bar.
[0026] Exemplarily, the wire diameter of the diamond wire may be 20-50 μm.
[0027] Specifically, the first silicon rod and the diamond wire can both be installed on a slicer. The diamond wire can be laid on the guide wheel system of the slicer and positioned and tensioned on the guide wheel; the first silicon rod can be installed on the workbench of the slicer through a resin plate and fixed with a clamp. It can be understood that the first silicon rod is located on one side of the diamond wire and is aligned with the cutting path of the diamond wire, thereby ensuring that the first silicon rod can be cut by the diamond wire.
[0028] S2. In order to remove the nickel layer of the diamond wire, the first silicon rod may be cut by a first cutting process, and the nickel layer is separated from the busbar by the first cutting process;
[0029] Specifically, the first cutting process can be considered as a process of sharpening the diamond wire. Optionally, in order to save costs, the first silicon rod can be a silicon rod that has failed the inspection.
[0030] In addition, in the process of removing the nickel layer of the diamond wire, loose diamond particles and stacked diamond particles can also be removed from the mother bar of the diamond wire, thereby improving the subsequent processing quality of silicon wafers.
[0031] In this step, the first cutting process may be an automated cutting process, that is, a preset first cutting program may be input into a slicer, so that the slicer automatically runs according to the first cutting program, thereby realizing automatic cutting of the first silicon rod, and realizing the sharpening of the diamond wire during the automatic cutting process.
[0032] S3, removing the first silicon rod and placing the second silicon rod on one side of the diamond wire;
[0033] Specifically, the second silicon rod is a qualified silicon rod that has passed the inspection, and the second silicon rod is used for cutting into silicon wafers.
[0034] The steps of arranging the second silicon rods can be the same as those of arranging the first silicon rods to simplify the process. Optionally, when the arranging position of the first silicon rods is determined, the second silicon rods can be arranged at the position of the first silicon rods by removing the first silicon rods.
[0035] S4. Cutting the second silicon rod into silicon wafers using a second cutting process.
[0036] Similarly, the second cutting process may be an automated cutting process, that is, a preset second cutting program may be input into a slicer, so that the slicer automatically runs according to the second cutting program, thereby realizing automatic cutting of the second silicon rod, and realizing the cutting process of the second silicon rod in the automatic cutting process.
[0037] Optionally, the diamond wire with the nickel layer removed can be rolled onto the wire feed wheel of the slicer, and after the slicer is warmed up for 2 to 5 minutes and all parameters are checked to be normal, the above automatic cutting can be performed.
[0038] In this step, since the diamond wire in the second cutting process is the diamond wire that has been sharpened in the first cutting process, its sharpness is improved. Therefore, in the process of cutting the second silicon rod into silicon wafers, the cutting parameters in the above-mentioned second cutting process can be adjusted, which not only shortens the cutting time of the second silicon rod but also improves the quality of the silicon wafers after cutting.
[0039] By applying the technical solution of the present invention, a method for cutting silicon wafers is provided. After the diamond wire is arranged on one side of the first silicon rod, the first silicon rod can be cut by the first cutting process. Since the diamond wire will be worn during the cutting of the first silicon rod, and the diamond wire may include a busbar and a nickel layer wrapping the busbar, the nickel layer of the diamond wire can be first worn away in the first cutting process, that is, the nickel layer of the diamond wire can be separated from the busbar of the diamond wire by the first cutting process. At this time, the busbar of the diamond wire is not hindered by the nickel layer, and it can be considered that the diamond wire has been sharpened, thereby increasing the sharpness of the blade surface of the diamond wire, so that the cutting ability of the diamond wire is improved. Then, in the case of increasing the sharpness of the diamond wire, the first silicon rod can be lifted upward to remove the first silicon rod, and the second silicon rod can be arranged on one side of the diamond wire to achieve the purpose of cutting the second silicon rod into silicon wafers by the second cutting process. It can be understood that the diamond wire used in the first cutting process and the second cutting process remains unchanged, but the sharpness of the diamond wire in the second cutting process is greater than that of the diamond wire in the first cutting process. Therefore, compared with the cutting of the second silicon rod in the prior art, since the embodiment of the present application also includes the above-mentioned first cutting process before cutting the second silicon rod, the embodiment of the present application can take less time to cut the second silicon rod, and the quality of the silicon wafer after cutting can be better. Therefore, through the embodiment of the present application, the output and yield of silicon wafers can be greatly improved, and the silicon wafer processing cost can be reduced.
[0040] In some optional embodiments, the moving direction of the diamond wire in the second cutting process is fixed.
[0041] It can be understood that the fixed moving direction of the diamond wire means that the moving direction of the diamond wire is fixed in a specific direction, that is, the moving direction of the diamond wire in the second cutting process can move from the left side of the second silicon rod to the right side of the second silicon rod, or from the right side of the second silicon rod to the left side of the second silicon rod, but it should be noted that the above two moving directions will not appear in the same second cutting process. This means that the diamond wire can have higher stability and faster moving speed during the cutting process, so that the diamond wire adopts a fixed moving direction in the second cutting process, which can improve the cutting efficiency of the diamond wire.
[0042] Specifically, in the above-mentioned second cutting process, the second silicon rod moves in a direction close to the diamond wire. On this basis, the moving direction of the diamond wire can be perpendicular to the moving direction of the second silicon rod, and during the movement of the diamond wire, its moving direction remains fixed.
[0043] For example, the second silicon rod may be located above the diamond wire, and the wire storage bin of the diamond wire may include a left wire storage bin located on the left side of the second silicon rod and a right wire storage bin located on the right side of the second silicon rod. At this time, when the second silicon rod approaches the diamond wire from top to bottom, the diamond wire may move from the left wire storage bin to the right wire storage bin until the second silicon rod is cut; or, the diamond wire may move from the right wire storage bin to the left wire storage bin until the second silicon rod is cut.
[0044] In order to improve the cutting efficiency of the diamond wire, in some optional implementations, the wire feeding length in the second cutting process may be 2000-5000 m.
[0045] Specifically, compared with the diamond wire in the first cutting process or in the prior art, since the diamond wire in the second cutting process has a sharper blade surface after being sharpened, when the wire feeding length is increased to 2000-5000m, the phenomenon of the diamond wire breaking during the cutting process due to insufficient cutting force of the diamond wire can be avoided. It should be noted that if the cutting force of the diamond wire is insufficient, if the wire feeding length is too long, the wire bow of the diamond wire will be large, which will cause the diamond wire to break during the cutting process.
[0046] In some optional embodiments, the feed speed in the first cutting process is the first feed speed, and the feed speed in the second cutting process is the second feed speed. The line speed in the first cutting process is the first line speed, and the line speed in the second cutting process is the second line speed. The feed speed refers to the moving speed of the cutting material (i.e., the first silicon rod or the second silicon rod) relative to the diamond wire. The line speed refers to the moving speed of the diamond wire itself.
[0047] For example, in some optional embodiments, the first feeding speed corresponding to the first silicon rod in the first cutting process may be 100-1000 μm / min. The second feeding speed corresponding to the second silicon rod in the second cutting process may be 100-4500 μm / min.
[0048] For example, in some optional embodiments, the first linear speed of the diamond wire in the first cutting process may be 800-1700 m / min, and the second linear speed of the diamond wire in the second cutting process may be 1300-2500 m / min.
[0049] In some optional embodiments, the first feed speed may be lower than the second feed speed, and the first linear speed may be lower than the second linear speed. It is understandable that in the above embodiment, since the first cutting process is used to sharpen the diamond wire, a slower feed speed and linear speed may be used to make the contact time between the diamond wire and the cutting material longer, so that the diamond particles of the diamond wire have more time to grind the cutting material. In contrast, the degree of wear of the cutting material on the diamond wire will be more serious.
[0050] In order to improve the efficiency and quality of silicon wafer cutting, in some optional implementations, the cutting method may further include: adding cutting fluid in the second cutting process.
[0051] In addition, in order to clean up the debris and diamond particles on the diamond wire in time, the cutting method may further include: adding cutting fluid in the first cutting process.
[0052] Exemplarily, the cutting fluid may be a cutting fluid with high COD (chemical oxygen demand).
[0053] Exemplarily, the process flow rate of the cutting fluid may be 180 to 240 L / Min.
[0054] Exemplarily, the cutting fluid cooling temperature is 16-23°C.
[0055] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, a silicon wafer cutting method of the present application will be described in detail below in conjunction with specific embodiments.
[0056] This embodiment relates to a specific method for cutting silicon wafers. After assembling the diamond wire, cutting fluid and guide wheel, and warming up and inspecting the slicer, the cutting method includes:
[0057] Step 1: stick the unqualified silicon rod with a width × height × length of 182.2 mm × 40 mm × 220 mm on a 10 mm thick resin board, assemble the resin board to the slicer, and align and heat the slicer.
[0058] Step 2: Input the first cutting program (acceleration and deceleration of 5.5s) shown in Table 1 into the slicer, and start automatic cutting using the first cutting program (cutting direction: left → right) shown in Table 1.
[0059] Step 3, as shown in Table 1, after cutting the unqualified silicon rod with a specification of 182.2 mm × 40 mm × 220 mm in width × height × length, the length of the diamond wire used is 37 kilometers, that is, the nickel layer of 37 kilometers of the diamond wire is ground off.
[0060] Step 4: After cutting is completed, lift the rod to complete the 37 km diamond wire sharpening.
[0061] Table 1
[0062]
[0063] Step 5: Glue the qualified silicon rod with a width × height × length of 182.2 mm × 187.75 mm × 820 mm onto a 10 mm thick resin board, assemble the resin board to a slicer, and align and heat the slicer.
[0064] Step 6: Input the second cutting program (acceleration and deceleration of 5.5s) shown in Table 2 into the slicer, and start automatic cutting using the second cutting program (cutting direction: left→right) shown in Table 2.
[0065] Step 7, as shown in Table 2, after cutting a qualified silicon rod with a width×height×length of 182.2mm×187.75mm×820mm, a total of 20 cycles are routed, using 30 kilometers of wire.
[0066] Step 8: Cutting is finished and the rod is lifted to complete the cutting.
[0067] Step 9. Grind off the nickel layer. The 37km diamond wire can be reused to cut 8 silicon rods.
[0068] Table 2
[0069]
[0070] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:
[0071] By applying the technical solution of the present invention, a method for cutting silicon wafers is provided. After the diamond wire is arranged on one side of the first silicon rod, the first silicon rod can be cut by the first cutting process. Since the diamond wire will be worn during the cutting of the first silicon rod, and the diamond wire may include a busbar and a nickel layer wrapping the busbar, the nickel layer of the diamond wire can be first worn away in the first cutting process, that is, the nickel layer of the diamond wire can be separated from the busbar of the diamond wire by the first cutting process. At this time, the busbar of the diamond wire is not hindered by the nickel layer, and it can be considered that the diamond wire has been sharpened, thereby increasing the sharpness of the blade surface of the diamond wire, so that the cutting ability of the diamond wire is improved. Then, in the case of increasing the sharpness of the diamond wire, the first silicon rod can be lifted upward to remove the first silicon rod, and the second silicon rod can be arranged on one side of the diamond wire to achieve the purpose of cutting the second silicon rod into silicon wafers by the second cutting process. It can be understood that the diamond wire used in the first cutting process and the second cutting process remains unchanged, but the sharpness of the diamond wire in the second cutting process is greater than that of the diamond wire in the first cutting process. Therefore, compared with the cutting of the second silicon rod in the prior art, since the embodiment of the present application also includes the above-mentioned first cutting process before cutting the second silicon rod, the embodiment of the present application can take less time to cut the second silicon rod, and the quality of the silicon wafer after cutting can be better. Therefore, through the embodiment of the present application, the output and yield of silicon wafers can be greatly improved, and the silicon wafer processing cost can be reduced.
[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A method for cutting a silicon wafer, characterized in that: include: Arranging a diamond wire on one side of the first silicon rod, wherein the diamond wire comprises a busbar and a nickel layer wrapping the busbar; Cutting the first silicon rod by a first cutting process, wherein the nickel layer is separated from the busbar by the first cutting process; Removing the first silicon rod and placing a second silicon rod on one side of the diamond wire; The second silicon rod is cut into silicon slices using a second cutting process.
2. The cutting method according to claim 1, characterized in that: The moving direction of the diamond wire in the second cutting process is fixed.
3. The cutting method according to claim 1, characterized in that: The wire feeding length in the second cutting process is 2000-5000m.
4. The cutting method according to claim 1, characterized in that: The feeding speed in the first cutting process is a first feeding speed, the feeding speed in the second cutting process is a second feeding speed, and the first feeding speed is smaller than the second feeding speed.
5. The cutting method according to claim 4, characterized in that: The first feeding speed is 100-1000 μm / min.
6. The cutting method according to claim 4, characterized in that: The second feeding speed is 100-4500 μm / min.
7. The cutting method according to any one of claims 1 to 6, characterized in that: The linear speed in the first cutting process is a first linear speed, the linear speed in the second cutting process is a second linear speed, and the first linear speed is less than the second linear speed.
8. The cutting method according to claim 7, characterized in that: The first linear speed is 800-1700 m / min.
9. The cutting method according to claim 7, characterized in that: The second linear speed is 1300-2500 m / min.
10. The cutting method according to any one of claims 1 to 6, characterized in that: The cutting method further comprises: A cutting fluid is added in the second cutting process.