Silicon wafer cutting method, silicon wafer cutting device and silicon wafer

Abstract

The invention provides a silicon wafer cutting method, a silicon wafer cutting device and a silicon wafer. The silicon wafer cutting method comprises the steps that a silicon rod bonded to a bearing plate is cut into silicon wafers through a cutting wire net; the silicon wafer is moved upwards until the silicon wafer is separated from the cutting wire net, and in the process of moving the silicon wafer upwards, the cutting wire net makes contact with the bearing plate and the silicon wafer in sequence and is finally separated from the silicon wafer; and when the cutting wire net is in contact with the bearing plate and the silicon wafer, the tension on the cutting wire net is different. Therefore, in the silicon wafer cutting process, by adjusting and controlling the tension of the cutting wire net, the tension of the cutting wire net can be matched with the position where the cutting wire net is located in the process of moving the silicon wafer upwards, and the quality of the silicon wafer can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon wafer processing, and in particular to a silicon wafer cutting method, a silicon wafer cutting device and a silicon wafer. Background Art

[0002] In the photovoltaic industry, the following are usually used: Figure 1 The schematic silicon wafer cutting device cuts the square silicon rod 10 to obtain silicon wafers.

[0003] The square silicon rod 10 is bonded to the supporting plate 11, and the supporting plate 11 is fixed under the crystal tray 12. The driving mechanism drives the crystal tray 12 to move downward along the Z direction shown in the figure, gradually approaching the continuously routed cutting wire mesh 20. The cutting wire mesh is used to cut the silicon rod. The tension on the cutting wire mesh at this time is the cutting tension. Under the action of the cutting tension, the silicon rod is cut by the wire mesh formed by the cutting wire mesh 20 to form several silicon wafers.

[0004] As the size and thinness of the wafers become increasingly large, after the slicing is completed, the driving mechanism pulls the crystal tray upward along the Z direction shown in the figure to drive the silicon wafer upward, so that when the silicon wafer is separated from the cutting wire mesh 20, the silicon wafers are severely adsorbed, which can easily produce deep scratches on the surface of the silicon wafer, causing silicon wafer defects. Summary of the invention

[0005] The embodiments of the present invention provide a silicon wafer cutting method, a silicon wafer cutting device and a silicon wafer to solve the problem that the surface of the silicon wafer is scratched when the cutting wire mesh is separated from the silicon wafer during the upward movement of the silicon wafer after cutting, resulting in defective silicon wafers.

[0006] In order to solve the above problem, the present invention is achieved as follows:

[0007] In a first aspect, an embodiment of the present invention provides a silicon wafer cutting method.

[0008] Cutting the silicon rod bonded to the carrier plate into silicon wafers by a cutting wire mesh;

[0009] The silicon wafer is moved upward until the silicon wafer is separated from the cutting wire mesh. During the process of moving the silicon wafer upward, the cutting wire mesh contacts the carrier plate and the silicon wafer in turn and finally separates from the silicon wafer. The tension on the cutting wire mesh is different when the cutting wire mesh contacts the carrier plate and the silicon wafer.

[0010] Optionally, the tension on the cutting wire mesh is different when the cutting wire mesh contacts the carrier plate and the silicon wafer, including:

[0011] During the process from the middle of the silicon wafer to the separation of the cutting wire web from the silicon wafer, the tension on the cutting wire web decreases.

[0012] Optionally, the tension on the cutting wire mesh is different when the cutting wire mesh contacts the carrier plate and the silicon wafer, including:

[0013] In the process of moving the silicon wafer upward, when the cutting wire mesh contacts the carrier plate and the silicon wafer, the tension on the cutting wire mesh is equal to or less than the cutting tension.

[0014] Optionally, the silicon wafer cutting method further comprises:

[0015] During the process of moving the silicon wafer upward, the cutting wire web is controlled to reciprocate.

[0016] Optionally, the cutting wire mesh is formed by winding diamond wire, and the cutting wire mesh includes a first wire mesh, a second wire mesh and a third wire mesh connected in sequence, wherein the first wire mesh is arranged close to the area where the silicon rod moves up and down, the first wire mesh is the wire mesh involved in cutting, and the tension on the first wire mesh is less than or equal to the cutting tension when the silicon wafer is moved upward.

[0017] Optionally, the tension of the first wire mesh is between 1N and 7N, the tension of the second wire mesh is between 1.5N and 8N, and the tension of the third wire mesh is between 2N and 9N.

[0018] In a second aspect, an embodiment of the present invention provides a silicon wafer cutting device, which includes a tension adjustment component, and the tension adjustment component is used to implement the silicon wafer cutting method described in the first aspect of the embodiment of the present invention to separate the silicon wafer and the cutting wire mesh.

[0019] Optionally, the silicon wafer cutting device comprises a first cutting roller, a second cutting roller and a reversing roller, the diamond wire is wound between the first cutting roller and the second cutting roller to form a first wire net, the diamond wire is wound between the first cutting roller and the reversing roller to form a second wire net, and the diamond wire is wound between the second cutting roller and the reversing roller to form a third wire net, wherein one of the first cutting roller and the second cutting roller is a main wire inlet roller, and the other is a main wire outlet roller;

[0020] The current of the driving motor corresponding to the main inlet roller is I 进 The current of the driving motor corresponding to the main outlet roller is I 出 , I 进 <I 出 .

[0021] Optionally, the silicon wafer cutting device further comprises a tension arm for controlling the tension of the cutting wire mesh, and in the process of moving the silicon wafer upward, the tension arm makes the tension of the cutting wire mesh less than or equal to the cutting tension used for silicon wafer cutting.

[0022] In a third aspect, an embodiment of the present invention further provides a silicon wafer, which is made by the silicon wafer cutting method described in the first aspect of the embodiment of the present invention or by the silicon wafer cutting device described in the second aspect of the embodiment of the present invention.

[0023] Optionally, the silicon wafer has scratches along the routing direction of the cutting wire network, and the depth of the scratches is 2 μm to 10 μm.

[0024] The scratch depth of the silicon wafer of the present application is 2 μm to 10 μm, and the scratch depth on the surface of the silicon wafer is greater than 10 μm, which causes little damage to the surface of the silicon wafer and does not lead to a reduction in the strength of the silicon wafer.

[0025] Optionally, the surface of the silicon wafer has line marks and scratches, and the angle between the scratches and the line marks is less than 20°.

[0026] The smaller the angle between the scratches and the line marks on the surface of the silicon wafer, the less likely the silicon wafer will get caught on the wire mesh when it is lifted upward along the cutting wire mesh, and the wire breakage rate is significantly reduced. In addition, the smaller the angle between the scratches and the line marks, the smoother the appearance of the silicon wafer and the higher the quality of the silicon wafer.

[0027] In the embodiment of the present invention, during the silicon wafer cutting process, when the silicon wafer is moved upward, the adjustment and control of the tension of the cutting wire mesh can make the tension on the cutting wire mesh match when it contacts the carrier plate and the silicon wafer, thereby solving the problem of scratches on the silicon wafer surface when the cutting wire mesh is separated from the silicon wafer during the existing silicon wafer cutting process, which is beneficial to improving the quality of the silicon wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0029] Figure 1 A simplified schematic diagram showing a process in which a silicon wafer cutting device moves a silicon wafer upwards in an embodiment of the present invention;

[0030] Figure 2 A flow chart of a first silicon wafer cutting method according to an embodiment of the present invention is shown;

[0031] Figure 3 A schematic diagram showing the position division of different stages of the process of moving the silicon wafer upwards in an embodiment of the present invention is shown;

[0032] Figure 4 A flow chart of a second silicon wafer cutting method according to an embodiment of the present invention is shown;

[0033] Figure 5 A simplified schematic diagram of a silicon wafer cutting device according to an embodiment of the present invention is shown;

[0034] Figure 6 A photo of scratches on a silicon wafer obtained without using the silicon wafer cutting method in the embodiment of the present invention is shown;

[0035] Figure 7 A photo of scratches on a silicon wafer obtained by using the silicon wafer cutting method in an embodiment of the present invention is shown.

[0036] Description of the accompanying drawings:

[0037] Square silicon rod 10, carrier plate 11, wafer support 12, cutting wire mesh 20, first wire mesh 20a, second wire mesh 20b, first wire mesh 20c. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are 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 are within the scope of protection of the present invention.

[0039] It should be understood that the references to "one embodiment" or "an embodiment" throughout the specification mean that the specific features, structures, or characteristics associated with the embodiment are included in at least one embodiment of the present invention. Therefore, the references to "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0040] In various embodiments of the present invention, it should be understood that the size of the serial numbers of the following processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0041] Combination Figure 1As shown in the figure, in the silicon wafer cutting device, the cutting wire net 20 is wound around rollers at different positions in the device to form a cutting wire net, wherein a part of the wire net is located directly below the crystal support 12. When the crystal support 12 carries the square silicon rod 10 and moves downward, the square silicon rod 10 is cut by relying on this part of the wire net. This part of the wire net is also the cutting part where the cutting wire net contacts the silicon wafer. Since the silicon wafer after cutting is thin, that is, the thickness of the silicon wafer is less than or equal to 140um, when such a silicon wafer is separated from the wire net, the gap between adjacent silicon wafers is narrow, and cutting fluid remains in the gap, which easily leads to the adsorption of adjacent silicon wafers. At this time, the driving mechanism drives the crystal support 12 and the silicon wafer bonded to the carrier plate 11 (for example, a resin plate) to move upward, so that when the cutting wire net is separated from the gap between the silicon wafers, it is easy for the cutting wire net to be hooked and torn off.

[0042] Therefore, the embodiment of the present invention improves the above-mentioned silicon wafer cutting process to solve the problem of scratches on the surface of the silicon wafer, resulting in defective silicon wafers. Figure 2 FIG. 1 is a flowchart of a silicon wafer cutting method provided by an embodiment of the present invention, wherein the silicon wafer cutting method comprises:

[0043] Step S101, cutting the silicon rod bonded to the carrier plate into silicon wafers by using a cutting wire mesh.

[0044] Step S102, moving the silicon wafer upward until the silicon wafer is separated from the cutting wire mesh, during which the cutting wire mesh contacts the carrier plate and the silicon wafer in turn and finally separates from the silicon wafer; wherein the tension on the cutting wire mesh when the cutting wire mesh contacts the carrier plate and the silicon wafer is different as follows: Figure 3 As shown, it is easy to understand that when the driving mechanism lifts the crystal tray to drive the silicon wafer bonded to the carrier plate 11 to move upward, when the silicon wafer is at different heights in the Z direction, the cutting wire mesh 20 contacts one of the silicon wafer, the adhesive surface, and the carrier plate. In an embodiment of the present invention, the stage in which the cutting wire mesh 20 moves from the middle of the silicon wafer to the stage in which it is separated from the silicon wafer is defined as the retraction stage T1. During slicing, the cutting wire mesh 20 usually cuts through a portion of the carrier plate 11. In an embodiment of the present invention, the stage in which the cutting wire mesh 20 moves from the carrier plate 11 to the adhesive surface is defined as the starting stage T2. The material corresponding to the adhesive surface is an adhesive, one side of the adhesive is the carrier plate 11, and the other side is the silicon wafer. The stage in which the cutting wire mesh 20 moves from the adhesive surface to the middle of the silicon wafer is defined as the transition stage T3. Combined with Figure 3 It is easy to understand that the transition stage T3 corresponds to the position from which the silicon wafer is bonded and fixed to the carrier plate 11 to the middle position of the side of the silicon wafer.

[0045] It should be noted that the knife retraction stage T1, that is, in the process of separating the silicon wafer from the cutting wire mesh, the cutting wire mesh is located at a certain position in the silicon wafer until it is completely separated. The middle part of the silicon wafer mentioned here specifically includes: along the side of the silicon wafer perpendicular to the carrier plate, a certain position away from one end of the carrier plate, for example, it can be the middle position of the side length of the silicon wafer or a position close to it.

[0046] In the traditional silicon wafer processing process, the tension of the cutting wire mesh 20 remains constant during the process of cutting to form silicon wafers and during the process of moving the silicon wafers upward after cutting. It is usually maintained at a higher tension in the slicing process stage. The tension value in the entire processing process is slightly less than the breaking tension of the diamond wire.

[0047] However, in the embodiment of the present invention, after the silicon wafer is cut, the process from the cutting wire mesh 20 in the carrier plate 11 to the contact with the silicon wafer and finally leaving the silicon wafer, that is, from Figure 3 The schematic T2 section moves to the T3 section, the T1 section, and finally leaves the T1 section, and the cutting wire net can be controlled to have different tensions in different sections.

[0048] Therefore, in the embodiment of the present invention, during the process of moving the silicon wafer upward, the adjustment and control of the tension of the cutting wire mesh can be adapted to match the position of the cutting wire mesh during the process of moving the silicon wafer upward, thereby solving the problem of scratches on the silicon wafer surface and resulting in silicon wafer quality problems.

[0049] Optionally, in an embodiment of the present application, during the process of moving the silicon wafer upward, the speed of the cutting wire mesh is greater than 0 and less than or equal to 0.1 m / s. When the rotation speed of the cutting wire mesh is greater than 0.1 m / s, the cutting wire mesh contacts the silicon wafer too much and generates too much heat, which increases the wear of the diamond particles on the surface of the silicon wafer, thereby causing a decrease in cutting quality. When the speed of the cutting wire mesh is equal to 0, due to the presence of diamond particles on the diamond wire, if the cutting wire mesh does not move, scratches perpendicular to the wire mark direction will appear on the silicon wafer during the process of moving the silicon wafer upward, resulting in poor quality of the silicon wafer.

[0050] Optionally, in the above-mentioned step S102, the tension on the cutting wire mesh is different when the cutting wire mesh contacts the supporting plate and the silicon wafer, which may include: the tension on the cutting wire mesh decreases during the process from the middle position of the silicon wafer to the time when the cutting wire mesh is detached from the silicon wafer.

[0051] Specifically, in one embodiment, in the retraction stage T1, the cutting wire net in contact with the silicon wafer in the silicon wafer cutting device is controlled to be in a relaxed state so that it has a smaller tension. Once the cutting wire net in the gap between the wafers is subject to greater frictional resistance or is hooked, the relaxed cutting wire net has a certain redundancy before being pulled and tensioned, which can reduce the risk of the cutting wire net breaking.

[0052] Furthermore, it should be noted that, considering that the lower half of the silicon wafer that is not bonded to the carrier plate is in a freely suspended state, the lower half of the silicon wafer is easily adsorbed close to each other and causes the cutting wire mesh to break. Therefore, taking the middle position of the side of the silicon wafer as a reference, from this position to the edge of the silicon wafer, that is, the movement range of the cutting wire mesh in the retraction stage T1, during the upward movement of the silicon wafer, when the cutting wire mesh enters this interval, the silicon wafer cutting device begins to keep the cutting wire mesh in a relaxed state with less tension.

[0053] The silicon wafer cutting method of the embodiment of the present invention can reduce the risk of wire breakage of the cutting wire net by reducing the tension of the cutting wire net to make it in a relaxed state during the knife retraction stage T1, thereby improving the yield rate of the silicon wafer.

[0054] Optionally, in the above-mentioned step S102, the tension on the cutting wire mesh when the cutting wire mesh contacts the supporting plate and the silicon wafer is different, and it may also include: in the process of moving the silicon wafer upward, when the cutting wire mesh contacts the supporting plate and the silicon wafer, the tension on the cutting wire mesh is equal to or less than the cutting tension.

[0055] It should be noted that the contact between the cutting wire mesh and the silicon wafer includes the entire process from the cutting wire mesh just contacting the silicon wafer to the cutting wire mesh detaching from the silicon wafer as the silicon wafer moves upward; the cutting tension mentioned in this application refers to the tension on the cutting wire mesh when the silicon rod is cut into silicon wafers. It can be understood that the cutting tension here corresponds to the tension on the cutting wire mesh when cutting the silicon wafer.

[0056] Specifically, in one implementation, in combination with the foregoing Figure 3 It is obvious that there is a big difference in the hardness of the carrier plate, adhesive and silicon wafer, and the hardness of the carrier plate and adhesive is smaller than that of the silicon wafer. As the driving mechanism pulls the crystal tray to drive the silicon wafer to move, the cutting wire mesh contacts the carrier plate, adhesive and silicon wafer in turn.

[0057] In the starting stage T2, due to the frictional contact with materials of different hardness when the cutting wire mesh moves relative to each other in the Z direction, the deformation of the wire bow in different materials varies greatly, and the cutting wire mesh is mainly in frictional contact with the carrier plate in this stage. Therefore, in order to reduce the difference in deformation of the cutting wire mesh between different materials and reduce the risk of the cutting wire mesh hanging up, the cutting wire mesh of the silicon wafer cutting device is controlled to be in a tensioned state in the starting stage T2. At this time, the tension of the cutting wire mesh can be the same as the cutting tension in the slicing process stage, that is, in the starting stage T2, the tension of the cutting wire mesh can be greater than the tension in the retracting stage T1. In addition, in the starting stage T2, on the premise of ensuring that the tension of the cutting wire mesh is greater than the tension in the retracting stage T1, the tension of the cutting wire mesh can also be controlled to be less than the cutting tension in the slicing process stage.

[0058] In addition, combined Figure 3 It is easy to understand that the transition stage T3 corresponds to the position from where the silicon wafer and the carrier are bonded and fixed to the middle position of the side of the silicon wafer. Therefore, when the relative movement of the cutting wire net in the Z direction is in the transition stage T3, the gap between adjacent silicon wafers is relatively stable, and its adsorption phenomenon is weaker than that in the retracting stage T1. In this stage, the cutting wire net can continue to maintain the tension state in the starting stage T2, or the cutting wire net can be switched to a relaxed state in advance before entering the retracting stage T1.

[0059] Alternatively, if Figure 4 As shown, the silicon wafer cutting method further includes:

[0060] Step S103, controlling the cutting wire mesh to reciprocate during the process of moving the silicon wafer upward.

[0061] In another embodiment of the present invention, the cutting wire net can be controlled to reciprocate during the upward movement of the silicon wafer, and the direction of the reciprocating motion is the wire routing direction. Thus, the height of the wire bow can be reduced to prevent the wire bow from contacting the cutting fluid pipeline and preventing the cutting wire net from breaking.

[0062] In another embodiment of the present invention, the cutting wire mesh 20 is formed by winding diamond wire, and the cutting wire mesh 20 includes a first wire mesh 20a, a second wire mesh 20b and a third wire mesh 20c connected in sequence, wherein the first wire mesh 20a is arranged close to the area where the silicon rod 10 moves up and down, and the first wire mesh 20a is a wire mesh involved in cutting, and the tension of the first wire mesh 20a is less than or equal to the cutting tension when the silicon wafer is moved upward.

[0063] It can be understood that the cutting wire mesh 20 used in the embodiment of the present application may include three wire meshes, namely, a first wire mesh 20a, a second wire mesh 20b and a third wire mesh 20c, wherein the first wire mesh 20a is located below the silicon rod 10, and when the silicon rod moves up and down, the first wire mesh 20a contacts the silicon rod 10. When the silicon rod is cut, the position where the first wire mesh is located is the cutting part of the silicon wafer cutting device, and when the silicon rod is cut, the tension on the first wire mesh is the cutting tension; when the silicon wafer moves upward, the corresponding tension on the first wire mesh is less than or equal to the cutting tension.

[0064] In another embodiment of the present invention, when the silicon wafer is moved upward, the tension of the first wire mesh 20a can be the part with the smallest tension in the entire wire mesh, that is, the first wire mesh 20a is in the most relaxed state. The overall tension of the wire mesh is F 总 , F 总 =F 破 *0.65, F 破That is, the breaking tension of the cutting wire mesh varies depending on the material, thickness, etc., and can be 1N to 10N. The tension of the first wire mesh 20a is F1, the tension of the second wire mesh 20b is F2, and the tension of the third wire mesh 20c is F3. 总 Also meets F 总 =F1+F2+F3. Therefore, by distributing the overall tension to different parts and controlling the tension difference of the wire mesh at different parts, the first wire mesh 20a is in a relaxed state with less tension. Specifically, when the silicon wafer moves upward, the tension of the first wire mesh 20a is less than or equal to the tension of the first wire mesh 20a when the silicon wafer is cut.

[0065] For example, in some embodiments, the tension F1 of the first wire web 20a is between 1N and 7N, for example, 1N, 2N, 3N, 4N, 5N, 6N or 7N. The tension of the second wire web 20b is between 1.5N and 8N, for example, 1.5N, 2N, 3N, 4N, 5N, 6N, 7N or 8N. The tension of the third wire web 20c is between 2N and 9N, for example, 2N, 3N, 4N, 5N, 6N, 7N, 8N or 9N.

[0066] An embodiment of the present invention provides a silicon wafer cutting device, which includes a tension adjustment component. The tension adjustment component is used to implement the silicon wafer cutting method of the aforementioned embodiment of the present invention to separate the silicon wafer from the cutting wire mesh.

[0067] It should be noted that the tension adjustment component can be a component composed of a driving motor that also has tension adjustment function, or can be a component composed of a tension arm that is specifically used to adjust the tension.

[0068] By applying the aforementioned silicon wafer cutting method to a silicon wafer cutting device, the problem of scratches on the surface of the silicon wafer, which leads to defective silicon wafers, can be significantly solved. For example, some comparative test results show that in a silicon wafer cutting device that does not adopt the silicon wafer cutting method, the proportions of broken wires, hanging wires, and scratches during the silicon wafer upward movement are 5.2%, 12%, and 3.2%, respectively, and in a silicon wafer cutting device that adopts the silicon wafer cutting method, the proportions of broken wires, hanging wires, and scratches during the silicon wafer upward movement are 1.5%, 2%, and 0.4%, respectively.

[0069] Optionally, refer to Figure 5The silicon wafer cutting device includes a first cutting roller 101, a second cutting roller 102 and a reversing roller 103, the diamond wire is wound between the first cutting roller 101 and the second cutting roller 102 to form a first wire net 20a, the diamond wire is wound between the first cutting roller 101 and the reversing roller 103 to form a second wire net 20b, and the diamond wire is wound between the second cutting roller 102 and the reversing roller 103 to form a third wire net 20c, wherein one of the first cutting roller 101 and the second cutting roller 102 is a main wire inlet roller, and the other is a main wire outlet roller;

[0070] The current of the driving motor corresponding to the main inlet roller is I 进 The current of the driving motor corresponding to the main outlet roller is I 出 , I 进 <I 出 .

[0071] Specifically, if Figure 5 As shown in FIG. 1 , the silicon wafer cutting device according to the embodiment of the present invention may include a first cutting roller 101, a second cutting roller 102 and a reversing roller 103. The portion of the diamond wire wound between the first cutting roller 101 and the second cutting roller 102 is a first wire mesh 20a, the portion wound between the first cutting roller 101 and the reversing roller 103 is a second wire mesh 20b, and the portion wound between the second cutting roller 102 and the reversing roller 103 is a third wire mesh 20c.

[0072] When the cutting wire web is running forward along the A direction shown in the figure, the first cutting roller 101 is the main wire inlet roller, and the second cutting roller 102 is the main wire outlet roller. When the cutting wire web is running backward along the B direction shown in the figure, the first cutting roller 101 is the main wire outlet roller, and the second cutting roller 102 is the main wire inlet roller.

[0073] Each cutting roller or reversing roller is driven by a corresponding drive motor, and the output torque of the drive motor is M=KT*I, where K is the constant value of the corresponding motor, T is the rated torque, and I is the working current of the motor. Set the current of the drive motor corresponding to the main inlet roller to I 进 , the current of the driving motor corresponding to the main roller is I 出 At the same time, M = F n *R, F n * is the tension of the corresponding wire web, i.e. one of F1, F2 and F3, and R is the radius of the corresponding roller. Therefore, the tension of the corresponding wire web can be changed by controlling the working current of the driving motor.

[0074] Therefore, based on the description of the above embodiment, when the cutting wire mesh is running in the positive direction along the A direction shown in the figure, if it is necessary to control and reduce the tension of the first wire mesh 20a, so that I 进 <I 出That is, the current of the driving motor of the first cutting roller 101 is less than the current of the driving motor of the second cutting roller 102. When the cutting wire web is reversely routed along the direction B shown in the figure, if it is necessary to control and reduce the tension of the first wire web 20a, I 进 <I 出 That is, the current of the driving motor of the second cutting roller 102 is smaller than the current of the driving motor of the first cutting roller 101 .

[0075] Optionally, the silicon wafer cutting device further comprises a tension arm for controlling the tension of the cutting wire mesh, and in the process of moving the silicon wafer upward, the tension arm makes the tension of the cutting wire mesh less than or equal to the cutting tension used for silicon wafer cutting.

[0076] Specifically, the silicon wafer cutting device of the embodiment of the present invention may also be equipped with a tension arm for adjusting the tension of the wire net. At this time, the swing angle of the tension arm may be adjusted so that the tension of the cutting wire net (for example, the first wire net of the aforementioned embodiment) is less than or equal to the cutting tension of the cutting wire net used for silicon wafer cutting during the upward movement of the silicon wafer. It is understandable that the adjustment of the swing angle of the tension arm may be achieved by controlling the electrical parameters of the tension motor, and the embodiment of the present invention will not be further described.

[0077] The embodiment of the present invention further provides a silicon wafer, which is manufactured by the silicon wafer cutting method described in the above embodiment of the present invention or by the silicon wafer cutting device described in the above embodiment of the present invention. Figure 6 As shown in FIG. 1 , a silicon wafer is processed without using the silicon wafer cutting method of the embodiment of the present invention. It can be seen that the surface J area has obvious scratches and is rough. Figure 7 As shown in FIG. 1 , a silicon wafer is processed by the silicon wafer cutting method according to an embodiment of the present invention, and it can be seen that the scratches in the K region of the surface are faint and basically disappear and are difficult to identify. Thus, the slicing quality of the silicon wafer is effectively improved.

[0078] Optionally, scratches are formed on the surface of the silicon wafer along the routing direction of the cutting wire mesh, and the depth of the scratches is 2 μm to 10 μm.

[0079] In addition, for the silicon wafer manufactured by the silicon wafer cutting method according to the embodiment of the present invention, the scratch depth measured in the K area shown in the figure is 2μm to 10μm. For example, the depth can be 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm or 10μm.

[0080] Optionally, the silicon wafer has line marks and scratches, and an angle between the scratches and the line marks is less than 20°.

[0081] Specifically, if Figure 7As shown, for the silicon wafer processed by the silicon wafer cutting method of the embodiment of the present invention, in the K area shown in the figure, the line marks formed by the cutting wire mesh routing are relatively straight, and the scratches formed by the cutting wire mesh scratching the silicon wafer surface in the process of moving the silicon wafer upward are basically the same as the direction of the line marks, without large fluctuations, and the angle between the line marks and the silicon wafer surface is less than 20°.

[0082] Compared with conventional process methods, these scratches are smaller in area and shallower in depth on the surface of the silicon wafer, making them subtle and difficult to identify. Therefore, the silicon wafer has a higher surface quality.

[0083] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0084] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A silicon wafer cutting method, characterized in that: include: Cutting the silicon rod bonded to the carrier plate into silicon wafers by a cutting wire mesh; The silicon wafer is moved upward until the silicon wafer is separated from the cutting wire mesh. During the process of moving the silicon wafer upward, the cutting wire mesh contacts the carrier plate and the silicon wafer in turn and finally separates from the silicon wafer. The tension on the cutting wire mesh is different when the cutting wire mesh contacts the carrier plate and the silicon wafer.

2. The silicon wafer cutting method according to claim 1, characterized in that: The tension on the cutting wire net is different when the cutting wire net contacts the carrier plate and the silicon wafer, including: During the process from the middle of the silicon wafer to the separation of the cutting wire web from the silicon wafer, the tension on the cutting wire web decreases.

3. The silicon wafer cutting method according to claim 1, characterized in that: The tension on the cutting wire net is different when the cutting wire net contacts the carrier plate and the silicon wafer, including: In the process of moving the silicon wafer upward, when the cutting wire mesh contacts the carrier plate and the silicon wafer, the tension on the cutting wire mesh is equal to or less than the cutting tension.

4. The silicon wafer cutting method according to claim 1, characterized in that: The silicon wafer cutting method further comprises: In the process of moving the silicon wafer upward, the cutting wire web is controlled to reciprocate.

5. The silicon wafer cutting method according to claim 1, characterized in that: The cutting wire mesh is formed by winding diamond wire, and the cutting wire mesh includes a first wire mesh, a second wire mesh and a third wire mesh connected in sequence, wherein the first wire mesh is arranged close to the area where the silicon rod moves up and down, the first wire mesh is the wire mesh involved in cutting, and the tension on the first wire mesh is less than or equal to the cutting tension when the silicon wafer is moved upward.

6. The silicon wafer cutting method according to claim 5, characterized in that: The tension of the first wire web is between 1N and 7N, the tension of the second wire web is between 1.5N and 8N, and the tension of the third wire web is between 2N and 9N.

7. A silicon wafer cutting device, characterized in that: The silicon wafer cutting device comprises a tension adjustment component, and the tension adjustment component is used to implement the silicon wafer cutting method according to any one of claims 1 to 6, so as to separate the silicon wafer and the cutting wire mesh.

8. The silicon wafer cutting device according to claim 7, characterized in that: The silicon wafer cutting device comprises a first cutting roller, a second cutting roller and a reversing roller, the diamond wire is wound between the first cutting roller and the second cutting roller to form a first wire net, the diamond wire is wound between the first cutting roller and the reversing roller to form a second wire net, and the diamond wire is wound between the second cutting roller and the reversing roller to form a third wire net, wherein one of the first cutting roller and the second cutting roller is a wire inlet main roller, and the other is a wire outlet main roller; The current of the driving motor corresponding to the main inlet roller is I 进 The current of the driving motor corresponding to the main outlet roller is I 出 , I 进 <I 出 .

9. The silicon wafer cutting device according to claim 7, characterized in that: The silicon wafer cutting device also includes a tension arm for controlling the tension of the cutting wire mesh. During the process of moving the silicon wafer upward, the tension arm makes the tension of the cutting wire mesh less than or equal to the cutting tension used for silicon wafer cutting.

10. A silicon wafer, characterized in that: The silicon wafer is made by the silicon wafer cutting method described in any one of claims 1 to 6 or by the silicon wafer cutting device described in any one of claims 7 to 9.

11. The silicon wafer according to claim 10, characterized in that: The silicon wafer has scratches along the routing direction of the cutting wire network, and the depth of the scratches is 2 μm to 10 μm.

12. The silicon wafer according to claim 10, characterized in that: The silicon wafer has a line mark and a scratch, and the angle between the scratch and the line mark is less than 20°.

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