Tension Adjusting Method for Wafer Cutting Wire and Wafer Slicing Machine

Abstract

The present invention provides a method for adjusting the tension of a wafer cutting wire and a slicing machine. The method for adjusting the tension of the wafer cutting wire includes: A. Monitoring the thickness of the wafer and / or the tension of the cutting wire, and determining an abnormal cutting wire; B. Calculating the tension adjustment compensation amount ΔTadjust of the abnormal cutting wire according to ΔTadjust = K1·ΔH + K2·(Ttarget - Tcurrent), where K1 is the thickness deviation weight coefficient, K2 is the tension attenuation weight coefficient, ΔH is the thickness deviation of the wafer cut in the previous cut, Ttarget is the target tension for the current cut, and Tcurrent is the tension when the abnormal cutting wire is determined to be abnormal; C. Using the wire wheel around which the abnormal cutting wire passes as the adjustment target, driving the adjustment target until the adjusted tension Tadjust of the abnormal cutting wire satisfies Tadjust - Tcurrent = ΔTadjust.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor device production, and in particular to a method for adjusting the tension of a wafer cutting wire and a slicing machine. Background Art

[0002] The multi-wire cutting process is a process in which a slicing machine and a diamond wire are used as a cutting device and a cutting wire respectively to cut a crystal bar to obtain wafers. At present, in multi-wire cutting processing, there are problems such as uneven wafer thickness, an increase in TVV (Total Wafer Thickness Variation), and wafers with abnormal thickness frequently appearing at high frequencies, resulting in a decrease in the wafer yield. The reasons for the deviation of the wafer thickness include the attenuation of the tension of the cutting wire.

[0003] The prior art provides a cutting wire tension adjustment and compensation means based on manual intervention, aiming to increase the tension of the cutting wire to offset the tension attenuation. The existing cutting wire tension adjustment and compensation means rely on the experience and skills of the operator. The operator needs to judge the attenuation degree of the cutting wire tension in real time. Improper operation is likely to cause fluctuations in the cutting wire tension, thereby affecting the cutting stability. Manual operation takes a long time and has hysteresis, and it cannot adapt to the cutting working conditions where the attenuation degree of the cutting wire tension changes dynamically in real time. For example, the cutting wire tension attenuates to different degrees in different cutting passes, while manual operation is usually constant value control, that is, manual operation is more suitable for adjusting and compensating for a specific degree of cutting wire tension attenuation. Summary of the Invention

[0004] In view of this, the present invention provides a method for adjusting the tension of a wafer cutting wire and a slicing machine that can replace manual operation to adjust and compensate the tension of the cutting wire to offset the attenuation of the cutting wire tension, so as to adapt to the cutting working conditions where the attenuation degree of the cutting wire tension changes dynamically in real time, thereby obtaining wafers with uniform and qualified thickness, reducing TVV (Total Wafer Thickness Variation), and increasing the yield of wafers.

[0005] The method for adjusting the tension of the wafer cutting wire of the present invention includes

[0006] A. Monitoring the wafer thickness and / or the cutting wire tension, and determining the abnormal cutting wire;

[0007] B. According to ΔT adjust =K1·ΔH + K2·(T target -T current ), calculating the tension adjustment compensation amount ΔT adjust of the abnormal cutting wire,

[0008] wherein, K1 is the thickness deviation weight coefficient, K2 is the tension attenuation weight coefficient, ΔH is the wafer thickness deviation of the previous cutting pass, T target is the target tension of the current cutting pass, and T current is the tension when the abnormal cutting wire is determined to be abnormal;

[0009] C. Using the thread guiding pulley bypassed by the abnormal cutting line as the adjustment target, drive the adjustment target until the adjusted tension T of the abnormal cutting line adjust satisfies T adjust -T current =ΔT adjust .

[0010] The tension adjustment method of the wafer cutting line of the present invention comprehensively considers the wafer thickness deviation of the previous cut and the cutting line tension deviation of the current cut. Starting from the second cut, the tension ΔT to be compensated for the tension adjustment of the next cut adjust is determined based on ΔT adjust =K1·ΔH + K2·(T target -T current ) on the basis of the previous cut, so that the tension compensated for each cut and the actual tension attenuation at the beginning of each cut are dynamically adapted. Therefore, the tension adjustment method of the wafer cutting line of the present invention can adapt to the cutting working conditions where the attenuation degree of the cutting line tension changes in real time and dynamically, without the need for manual real-time judgment of the attenuation degree of the cutting line tension, no longer relying on the experience and skills of the operator, and can avoid the cutting line tension fluctuation caused by improper operation to ensure stable cutting.

[0011] In some embodiments, step C includes

[0012] C1. According to the relationship formula between the cutting line tension T and the position p of the thread guiding pulley T(p) , determine the amount of adjustment Δ p to be adjusted for the adjustment target;

[0013] C2. Drive the adjustment target according to the amount of adjustment Δ p to complete the tensioning.

[0014] In the first embodiment of the present invention, the relationship formula between the cutting line tension T and the position p of the thread guiding pulley T(p) is:

[0015] T = , p = θ;

[0016] The amount of adjustment Δ p =Δθ=(θ2 - θ1),

[0017] where θ2 is the angular position when the adjustment target completes the tensioning, θ1 is the angular position of the adjustment target when the abnormal cutting line is determined to be abnormal, τ is the output torque of the rotating motor, and L is the distance from the rotation center of the adjustment target to the revolution center of the adjustment target.

[0018] In some embodiments, both the rotation center and the revolution center of the adjustment target are parallel to the axis of the winding roller shaft

[0019] -10° ≤ θ ≤ 10°, θ increases as the adjustment target moves away from the wire winding roller shaft, and θ = 0° when the rotation center of the adjustment target is vertically above the revolution center.

[0020] In the second embodiment of the present invention, the relationship between the cutting line tension T and the position p of the wire passing wheel T(p) is:

[0021] T = K w ·( - L0), p = (S, 0);

[0022] The adjustment activity Δ p = Δ S = - ,

[0023] wherein, S is the horizontal position coordinate of the rotation center of the adjustment target, Δ S is the translation amount of the adjustment target within the preset adjustment interval, K w is the elastic coefficient of the cutting line, L0 is the initial length of the cutting line when it passes through, and H is the offset distance of the adjustment target from the top.

[0024] In some embodiments, the rotation center of the adjustment target is parallel to the axis of the wire winding roller shaft, and the translation direction of the adjustment target within the preset adjustment interval is perpendicular to the rotation center of the adjustment target;

[0025] a ≤ S ≤ b, and S increases as the adjustment target moves away from the wire winding roller shaft.

[0026] The slicing machine of the present invention is used to execute the method of the first embodiment, including a machine body, a wire winding roller shaft, a wire roller driving member, a wire passing wheel, an adjusting swing arm, and a tensioning driving member. The wire winding roller shaft is rotatably arranged on the machine body, the wire roller driving member is drivingly connected to the wire winding roller shaft, the adjusting swing arm is hinged to the machine body, the tensioning driving member is drivingly connected to the adjusting swing arm, and the wire passing wheel is rotatably arranged on the adjusting swing arm.

[0027] In some embodiments, the axis of the wire winding roller shaft, the axis of the wire passing wheel, and the rotation center of the adjusting swing arm are parallel to each other. The axis of the wire passing wheel and the rotation center of the adjusting swing arm respectively form the rotation center and the revolution center of the wire passing wheel. The tensioning driving member is used to drive the wire passing wheel to move away from the wire winding roller shaft, so as to increase the tension of the cutting line bypassing the wire passing wheel; and / or,

[0028] The wire passing wheel includes a middle wire passing wheel. The wire winding roller shaft has a wire winding section extending along the axial direction, and the two ends of the wire winding section are equidistant from the opposite sides of the middle wire passing wheel.

[0029] Another slicer of the present invention is used to execute the method of Example 2, including a machine body, a winding roller, a wire roller driving member, a wire passing wheel, a translation mechanism and a tensioning driving member. The winding roller is rotatably arranged on the machine body, the wire roller driving member is driven and connected to the winding roller, the translation mechanism is slidably connected to the machine body, the tensioning driving member is driven and connected to the translation mechanism, and the wire passing wheel is rotatably arranged on the translation mechanism.

[0030] In some embodiments, the axis of the winding roller is parallel to the axis of the wire wheel, and the translation mechanism and the body form a moving pair so that the translation mechanism translates in a direction perpendicular to the axis of the wire wheel.

[0031] The tensioning drive is used to drive the wire wheel to move away from the winding roller, so as to increase the tension of the cutting wire passing around the wire wheel; and / or,

[0032] The winding roller comprises a top winding roller, wherein the side of the top winding roller facing away from the ground is higher than the side of the spool facing away from the ground; and / or,

[0033] The wire passing wheel comprises a middle wire passing wheel, and the winding roller shaft has a winding section extending in the axial direction, and two ends of the winding section are equidistant from the opposite sides of the middle wire passing wheel.

[0034] The slicer of the present invention can start from the second knife and cut the slice according to ΔT based on the previous knife. adjust =K1·ΔH+K2·(T target -T current ) Determine the tension ΔT required for the next cut adjust , so that the compensation tension obtained by each cut and the actual tension attenuation at the beginning of each cut are dynamically adapted. Therefore, the slicer of the present invention can adapt to the cutting conditions where the degree of attenuation of the cutting line tension changes dynamically in real time. There is no need for manual real-time judgment of the attenuation degree of the cutting line tension, and it no longer depends on the experience and skills of the operator. It can avoid fluctuations in the cutting line tension caused by improper operation to ensure stable cutting. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of a partial structure of a slicer according to an embodiment of the present invention;

[0036] Figure 2 Schematic diagram of the structure of a slicer for implementing the tension adjustment method of a wafer cutting line according to the first embodiment of the present invention;

[0037] Figure 3 Schematic diagram of the operation of a slicer when tensioning a wafer cutting line for implementing the method for adjusting the tension of a wafer cutting line according to the first embodiment of the present invention;

[0038] Figure 4Schematic structural diagram of a slicing machine for implementing the method for adjusting the tension of a wafer cutting wire according to Embodiment 2 of the present invention before adjusting the cutting wire tension;

[0039] Figure 5 Schematic structural diagram of a slicing machine for implementing the method for adjusting the tension of a wafer cutting wire according to Embodiment 2 of the present invention when adjusting the cutting wire tension.

[0040] Description of reference numerals: 100, slicing machine; 10, machine body; 20, wire winding roller shaft; 21, first wire winding roller shaft; 22, second wire winding roller shaft; 23, third wire winding roller shaft; 30, wire passing wheel; 40, adjusting swing arm; 41, first self-rotation center; 42, revolution center; 50, translation mechanism; 51, second self-rotation center; 60, cutting wire; 70, tension driving member; 80, monitoring unit. Detailed implementation manners

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more of the related listed items.

[0043] The present invention provides a method for adjusting the tension of a wafer cutting wire and a slicing machine 100. The method for adjusting the tension of a wafer cutting wire is used for a multi-wire cutting process. The slicing machine 100 is used to perform the multi-wire cutting process. The multi-wire cutting process aims to cut a wafer bar into a plurality of wafers that are arranged along the axial direction of the wafer bar, have uniform thickness, and smooth cut surfaces by using a cutting net formed by the cutting wire 60. The wafers are used as raw material parts for various semiconductor devices.

[0044] Refer to Figure 1 to Figure 2, the slicing machine 100 of the present invention includes a machine body 10, a wire roller driving member, and a plurality of wire winding roller shafts 20. The plurality of wire winding roller shafts 20 are arranged at intervals with respect to each other and their respective axes are parallel to each other. The cutting wire 60 is a diamond wire. The cutting wire 60 is wound around the outer circumferential surfaces of the plurality of wire winding roller shafts 20 to form a cutting net. The cutting net extends from the outer circumferential side of one wire winding roller shaft 20 to the outer circumferential side of another wire winding roller shaft 20. The wire roller driving member is used to connect and drive at least one of the wire winding roller shafts 20 to rotate and drive the cutting wire 60. The axial direction of the ingot is perpendicular to the arrangement direction of the cutting wire 60 segments in the cutting net. When the ingot is translated from one side of the cutting net and penetrates the plane where the cutting net is located until it reaches the other side of the cutting net, and at the same time the wire roller driving member drives the wire winding roller shaft 20 to rotate and drags the cutting net to move, the cutting net cuts the ingot into a plurality of wafers.

[0045] Existing multi-wire cutting processes and slicing machines 100 are difficult to ensure a high yield rate of wafers. When cutting and processing an ingot, there are problems such as uneven wafer thickness, an increase in TVV (total wafer thickness variation), and the frequent occurrence of wafers with abnormal thickness, especially the thickness of the wafers in the middle position is significantly smaller. That is, after the same ingot is cut into a plurality of wafers, the thickness of the wafers shows a trend of decreasing first and then increasing from one end of the ingot to the other end. The larger the axial dimension of the ingot, the more serious the situation of the smaller thickness of the wafers in the middle position. The main reason for the smaller wafer thickness mainly includes the tension attenuation of the cutting wire 60, that is, the tension of the cutting wire 60 used to cut the middle position of the ingot is less than the tension of the cutting wire 60 used to cut the two ends of the ingot.

[0046] In view of this, the present invention provides a method for adjusting the tension of a wafer cutting wire, aiming to tension and adjust the cutting wire 60 with tension attenuation so as to compensate for the tension of the cutting wire 60. By implementing the method for adjusting the tension of the wafer cutting wire, multi-wire cutting processes can cut wafers with uniform and qualified thickness, reduce TVV (total wafer thickness variation), and improve the yield rate of wafers. The slicing machine 100 of the present invention further includes a monitoring unit 80 and a wire guiding pulley 30. The monitoring unit 80 includes a wafer thickness monitoring module and / or a cutting wire 60 tension sensor. The wafer thickness monitoring module is used to monitor the thickness of the wafers, and the cutting wire 60 tension sensor is used to monitor the tension of the cutting wire 60. The wire guiding pulley 30 is movably arranged relative to the machine body 10. Refer to Figure 1, the axis of the wire guiding wheel 30 and the axis of the winding roller shaft 20 are parallel to each other. The wire guiding wheel 30 and the winding roller shaft 20 are also bypassed by the cutting wire 60. The difference is that the axis of each winding roller shaft 20 is fixed relative to the machine body 10, while the axis of the wire guiding wheel 30 is movable relative to the machine body 10. The wire guiding wheel 30 changes the tension of the cutting wire 60 by moving relative to the machine body 10, thereby changing the tension of the cutting net. After the tension of the cutting wire 60 decays, in order to compensate for the tension of the cutting wire 60 to offset the influence of the decay on the wafer thickness, the wire guiding wheel 30 can be controlled to move in any direction away from the winding roller shaft 20 to increase the tension of the cutting wire 60. Usually, the cutting wire 60 with tension decay can be determined according to past production and processing experience before formal cutting processing, that is, one or several cutting wires 60 used to cut the wafers at the middle position, based on the fact that the thickness of the wafers at the middle position is significantly smaller; in other cases, the cutting wires 60 with tension decay are not limited to the cutting wires 60 for cutting the wafers at the middle position, and the tension of each cutting wire 60 on the cutting net may decay.

[0047] The method for adjusting the tension of the wafer cutting wire of the present invention includes:

[0048] A. Monitoring the wafer thickness and / or the tension of the cutting wire 60, and determining the abnormal cutting wire 60;

[0049] B. According to ΔT adjust = K1·ΔH + K2·(T target - T current ), obtaining the tension adjustment compensation amount ΔT adjust ,

[0050] wherein, K1 is the thickness deviation weight coefficient, K2 is the tension decay weight coefficient, K1 and K2 are two dimensionless constants, the value range of K1 is 0.1 to 2.0, the magnitude of K1 reflects the influence degree of the wafer thickness deviation of the previous cut on the tension of the cutting wire 60 in this cut, the value range of K2 is 0.1 to 1.5, ΔH is the wafer thickness deviation of the previous cut, ΔH = H target - H previous , H target is the target thickness of the wafer to be cut this time set in advance, H previous is the thickness (calculated value) of the wafer cut in the previous cut, the method for calculating H previous includes the average value method, the weighted average method, the regional segmentation method, etc., T target is the target tension of this cut, T current is the tension when the abnormal cutting wire 60 is determined to be abnormal;

[0051] C. Taking the wire guiding wheel 30 bypassed by the abnormal cutting wire 60 as the adjustment target, driving the adjustment target until the adjusted tension T of the abnormal cutting wire 60adjust Meet T adjust -T current =ΔT adjust .

[0052] Specifically, step C includes:

[0053] C1. According to the relationship between the tension T of the cutting wire 60 and the position p of the wire passing wheel 30 T(p) , determine the amount of adjustment Δ of the adjustment target p ;

[0054] C2. Drive the adjustment target according to the amount of adjustment Δ p and complete the tensioning.

[0055] Generally, at the beginning of cutting the ingot, the slicing machine 100 will be initialized. The initialization settings include setting the tension range of the cutting wire 60 and calibrating the initial tension of the cutting mesh. Therefore, when the cutting wire 60 makes the first cut on the first ingot after the initialization settings are completed, the tension of the cutting wire 60 is calibrated without attenuation. Starting from cutting the second ingot, the tension of the cutting wire 60 attenuates. Therefore, the method for adjusting the tension of the wafer cutting wire of the present invention is applicable to the ingot cutting operation of the thickness cutting tool after the first cutting tool is completed. The first cutting tool is the first cut of the cutting wire 60 on the first ingot.

[0056] Compared with the prior art, the method for adjusting the tension of the wafer cutting wire of the present invention comprehensively considers the wafer thickness deviation of the previous cut and the tension deviation of the cutting wire 60 in the current cut. In the multi-wire cutting process, the cutting wire tension of each cut and the material removal condition of the ingot to be cut will affect the cutting effect of the next cut: if the wafer thickness deviation of the previous cut is relatively large, it will cause obvious changes in the stress distribution of the cutting wire, thereby affecting the local stretching or relaxation of the cutting wire during the next cut; the wafer thickness deviation of the previous cut may cause abnormal local temperature of the cutting wire, and the temperature change affects the expansion degree of the cutting wire, so that the cutting wire tension during the next cut is affected by the expansion of the cutting wire and changes; in addition, the wafer thickness deviation of the previous cut will cause the cutting wire to accumulate fatigue and the fatigue stress cannot be released in time, which will also cause the cutting wire tension during the next cut to be insufficient or excessive. If the cutting wire tension error generated by the wafer thickness deviation of the previous cut cannot be compensated in time, the cutting wire tension error will gradually accumulate. Therefore, starting from the second cut, the tension ΔT adjust required for tension adjustment of the next cut is determined based on ΔT adjust =K1·ΔH + K2·(T target -T current ) on the basis of the previous cut. For example:

[0057] In the second cutting pass (i.e., the second cut), the tension ΔT to be compensated adjust is determined based on the first cut. ΔH is the wafer thickness deviation of the first cut. The wafer thickness deviation ΔH is the difference between the target wafer thickness H of the first cut target and the actual wafer thickness H of the first cut previous , that is, ΔH = H target − H previous , T target is the tension to be adjusted for this pass (i.e., the second cutting pass), and T current is the current tension of the second cut, that is, the tension of the cutting wire 60 during the start of the second cut;

[0058] In the fourth cutting pass (i.e., the fourth cut), the tension ΔT to be compensated adjust is determined based on the third cut. ΔH is the wafer thickness deviation of the third cut. The wafer thickness deviation ΔH is the difference between the target wafer thickness H of the third cut target and the actual wafer thickness H of the third cut previous , that is, ΔH = H target − H previous , T target is the tension to be adjusted for this pass (i.e., the fourth cutting pass), and T current is the current tension of the fourth cut, that is, the tension of the cutting wire 60 during the start of the fourth cut.

[0059] In this way, the tension compensated for each cutting pass dynamically adapts to the actual tension attenuation at the beginning of each cutting pass. Therefore, the tension adjustment method of the wafer cutting wire of the present invention can adapt to the cutting conditions where the tension attenuation degree of the cutting wire 60 changes in real time and dynamically, better meeting the actual requirements of ingot cutting and processing. There is no need for manual real-time judgment of the tension attenuation degree of the cutting wire 60, and it no longer depends on the experience and skills of the operator. It can avoid large fluctuations in the tension of the cutting wire 60 caused by improper manual operation, ensuring the stable operation of the slicing machine 100. While considering the cutting wire tension deviation of the current cut, the wafer thickness deviation of the previous cut is also taken into account, avoiding the influence of the thickness deviation of the previous cut on the cutting wire tension from gradually accumulating and magnifying in subsequent cutting passes. In each cutting pass, the cutting wire tension error caused by the wafer thickness deviation of the previous cut can be compensated and corrected, thereby ensuring a stable cutting wire tension for each cut and a uniform tension distribution for each cutting wire during each cut.

[0060] In contrast, the existing means for adjusting and compensating the tension of the cutting wire 60 rely on the skills of the operator. Manual operation is only based on experience and can only compensate the tension of the cutting wire 60 in a fixed value. The tension compensation amount after manual adjustment often cannot meet the cutting requirements of the current cutting pass. After compensating the tension, it is still possible to cut out wafers that are too thin. The significant fluctuation of the tension of the cutting wire 60 caused by manual operation will reduce the smoothness of the cut surface of the wafer, and it is difficult to meet the quality evaluation indicators such as wafer wire marks and TTV. It can only meet the wafer thickness index alone. Each time of cutting, the cutting wire contains the tension error caused by the thickness deviation of the previous wafer.

[0061] Specifically, the formula for calculating H previous by the average value method is , and its calculation idea is to first measure the thickness values at different positions of the wafer obtained by the previous cutting pass, and then calculate the arithmetic average of these thickness values; the formula for calculating H previous by the weighted average method is . Compared with the calculation by the average value method, the weighted average method assigns a higher weight to the thickness of the key area of the wafer (such as the middle part of the wafer). The means for measuring the thickness values at different positions of the wafer obtained by the previous cutting pass can be to select points and collect in real time using a laser thickness gauge, or to scan the wafer obtained by the previous cutting pass.

[0062] It is worth supplementing that T target , as the target tension for this cutting pass, is only related to the tension adjustment and compensation amount ΔT adjust for this cutting pass, and has nothing to do with the tension adjustment and compensation amount ΔT adjust for the previous cutting pass or the next cutting pass. For example, in the second cutting pass, the target tension T adjust used to calculate the tension to be compensated for the second cutting pass according to T current −T adjust =ΔT target is only the target tension for the second cutting pass, and has nothing to do with the target tensions for the first cutting pass, the third cutting pass, or the fourth cutting pass. In some cases, the target cutting tensions in different cutting passes are different.

[0063] Furthermore, T target , as the target tension for this cutting pass, can be either a fixed value or multiple different values. When the T target for a certain cutting pass is a fixed value, the cutting force exerted by the cutting wire 60 on the ingot is equal in each cutting stage of this cutting pass. T target being a fixed value is applicable to the cutting working conditions with stable cutting conditions and uniform ingot material; when the T targetWhen it takes multiple different values, the cutting force exerted by the cutting wire 60 on the ingot may be different at each cutting stage of this cutting. It is equivalent to multiple different values jointly constituting the dynamic target tension of this cutting, that is, T target is a dynamic value and changes as the cutting stage of this cutting progresses. Therefore, a fixed value T target or a dynamic value T target can be selected as the target tension of this cutting according to the actual cutting conditions and the uniformity of the ingot material.

[0064] H target is used as the target wafer thickness of this cutting and is only related to the tension adjustment compensation amount ΔT adjust of this cutting, and has nothing to do with the tension adjustment compensation amount ΔT adjust of the previous cutting or the next cutting. For example, in the second cut, the H adjust used to calculate the tension to be compensated for the second cut according to ΔT target = K1·(H previous - H target ) + K2·(T current - T target is only the target wafer thickness of the second cut and has nothing to do with the target wafer thickness of the first cut, the third cut or the fourth cut. In some cases, the target wafer thicknesses in different cutting passes may be equal.

[0065] The relationship between the tension T of the cutting wire 60 and the position p of the wire pulley 30 T(p) , the amount of adjustment Δ p to be adjusted for the adjustment target both depend on the installation method of the wire pulley 30 in the slicing machine 100 and the movement form of the wire pulley 30. Figure 2 to Figure 3The shown slicing machine 100 further includes an adjusting swing arm 40 and a tension driving member 70. One end of the adjusting swing arm 40 is hinged to the machine body 10, and the wire passing wheel 30 is rotatably mounted at the other end of the adjusting swing arm 40. The tension driving member 70 is drivingly connected to the adjusting swing arm 40 so as to be able to drive the adjusting swing arm 40 to rotate relative to the machine body 10. The wire passing wheel 30 moves as the adjusting swing arm 40 rotates relative to the machine body 10, thereby realizing the movement of the wire passing wheel 30 relative to the winding roller shaft 20. One end of the adjusting swing arm 40 where the wire passing wheel 30 is mounted forms a first rotation center 41 for the wire passing wheel 30 to rotate itself, and the other end of the adjusting swing arm 40 rotatably connected to the machine body 10 forms a revolution center 42 for the wire passing wheel 30 to revolve relative to the machine body 10. The wire passing wheel 30 rotates around the first rotation center 41 to adapt to the movement of the cutting wire 60. When the wire passing wheel 30 rotates around the revolution center 42 and moves away from the winding roller shaft 20 under the drive of the tension driving member 70, the tension of the cutting wire 60 increases, thereby realizing the tensioning of the cutting wire 60. When the tension driving member 70 drives the adjusting swing arm 40 to rotate around the revolution center 42 to tension the cutting wire 60, the axis of the wire passing wheel 30 passing through the first rotation center 41 rotates around the revolution center 42 to form an arc-shaped trajectory. Optionally, Figure 2 to Figure 3 In the shown slicing machine 100, the axis of the winding roller shaft 20, the axis of the wire passing wheel 30, and the rotation center of the adjusting swing arm 40 are parallel to each other. The wire passing wheel 30 is Figure 1 rotating around the revolution center 42 in the shown YOZ plane. Figure 3 In the shown slicing machine 100, the angle range for the tension driving member 70 to drive the adjusting swing arm 40 to rotate around the revolution center 42 is 20°; in other embodiments, the angle range for the tension driving member 70 to drive the adjusting swing arm 40 to rotate around the revolution center 42 is not limited to 20°.

[0066] Further, the outer peripheral wall of the winding roller shaft 20 has a winding section for the cutting wire 60 to wind around and pass through. The winding section extends along the axial direction of the winding roller shaft 20. The wire passing wheel 30 at least includes a middle wire passing wheel 30. The distances from the opposite sides of the middle wire passing wheel 30 to the two ends of the winding section are equal. The middle wire passing wheel 30 is specifically used for tensioning and compensating the tension of the cutting wire 60 in the middle position of the cutting net, so as to specifically overcome the problem that the thickness of the wafers in the middle position is abnormally small. When the tension driving member 70 drives the middle wire passing wheel 30 to rotate around the revolution center 42 and move away from the winding roller shaft 20, the cutting wire 60 passing around the middle wire passing wheel 30 obtains tension compensation and is thus tensioned. The tension of this cutting wire 60 is adjusted to be close to the tension of the cutting wires 60 at both sides of the cutting net. The wafers cut by this cutting wire 60 finally meet the thickness requirements, and the multiple wafers cut from the same ingot by the cutting net have relatively uniform and unified thickness dimensions. It can be understood that on the basis of the middle wire passing wheel 30, the number of wire passing wheels 30 can be further increased. The multiple wire passing wheels 30 are arranged at intervals in sequence along the axial direction of the winding roller shaft 20. The uniformity of the tension of the cutting wires 60 in the cutting net increases with the increase in the number of wire passing wheels 30, and the thickness dimensions of the multiple wafers cut from the same ingot by the cutting net are more uniform and consistent, and the yield rate of the wafers is higher.

[0067] Figure 4 to Figure 5 The slicing machine 100 shown also includes a translation mechanism 50 and a tension driving member 70. The translation mechanism 50 is slidably connected to the machine body 10. The wire passing wheel 30 is rotatably installed on the translation mechanism 50. The tension driving member 70 is drivingly connected to the translation mechanism 50 so as to be able to drive the translation mechanism 50 to translate relative to the machine body 10. The wire passing wheel 30 moves along with the translation mechanism 50 relative to the machine body 10, thereby realizing the movement of the wire passing wheel 30 relative to the winding roller shaft 20. The position on the translation mechanism 50 where the wire passing wheel 30 is installed and the axis of the wire passing wheel 30 form a second rotation center 51 for the wire passing wheel 30 to rotate. The wire passing wheel 30 rotates around the second rotation center 51 to adapt to the movement of the cutting wire 60. When the wire passing wheel 30 follows the translation mechanism 50 to translate and move away from the winding roller shaft 20 under the drive of the tension driving member 70, the tension of the cutting wire 60 increases, thereby realizing the tensioning of the cutting wire 60. When the tension driving member 70 drives the translation mechanism 50 to move relative to the machine body 10 to tension the cutting wire 60, the axis of the wire passing wheel 30 passing through the second rotation center 51 translates to form a straight line trajectory. Optionally, the axis of the winding roller shaft 20 is parallel to the axis of the wire passing wheel 30. The translation mechanism 50 and the machine body 10 form a moving pair so that the translation mechanism 50 translates along the direction perpendicular to the axis of the wire passing wheel 30. The wire passing wheel 30 translates in the YOZ plane shown along the direction parallel to the Y axis. Figure 1 shown in the YOZ plane along a direction parallel to the Y axis.

[0068] Further, the outer peripheral wall of the winding roller shaft 20 has a winding section that extends along the axial direction of the winding roller shaft 20. The wire passing wheel 30 at least includes a middle wire passing wheel 30. The distances from the opposite sides of the middle wire passing wheel 30 to the two ends of the winding section are equal. The middle wire passing wheel 30 is specifically used for tensioning and compensating the tension of the cutting wire 60 in the middle position of the cutting net, so as to specifically overcome the problem of abnormally small thickness of the wafers in the middle position. When the tension driving member 70 drives the middle wire passing wheel 30 to translate relative to the machine body 10 and move away from the winding roller shaft 20, the cutting wire 60 passing around the middle wire passing wheel 30 is tension compensated and thus tensioned. The tension of the cutting wire 60 is adjusted to be close to the tension of the cutting wires 60 at the two side positions in the cutting net. The wafers cut by the cutting wire 60 finally meet the thickness requirements, and the multiple wafers cut from the same ingot by the cutting net have relatively uniform thickness dimensions. It can be understood that on this basis, the number of wire passing wheels 30 can be further increased. For example, two or more wire passing wheels 30 can be provided. The multiple wire passing wheels 30 are arranged at intervals in sequence along the axial direction of the winding roller shaft 20. The uniformity of the tension of the cutting wires 60 in the cutting net increases with the increase in the number of wire passing wheels 30, and the thickness dimensions of the multiple wafers cut from the same ingot by the cutting net become more uniform, and the yield rate of the wafers is higher.

[0069] Based on the above two wafer slicing machines 100, the present invention provides two embodiments of the method for adjusting the tension of the wafer cutting wire. The two embodiments respectively propose two relational expressions between the tension T of the cutting wire 60 and the position p of the wire passing wheel 30 T(p) , and respectively propose the amount of adjustment Δ of two adjustment targets p . The method for adjusting the tension of the wafer cutting wire in Embodiment 1 is applicable to the wafer slicing machine 100 as shown in Figure 2 to Figure 3 , that is, applicable to the wafer slicing machine 100 in which the wire passing wheel 30 is installed on the adjusting swing arm 40, the adjusting swing arm 40 is hinged to the machine body 10, and the tension driving member 70 is drivingly connected to the adjusting swing arm 40 and used to drive the adjusting swing arm 40 to rotate. The tension driving member 70 in the wafer slicing machine 100 can adopt a rotary motor, and the rotary motor outputs a torque τ with a constant magnitude to the adjusting swing arm 40; the method for adjusting the tension of the wafer cutting wire in Embodiment 2 is applicable to the wafer slicing machine 100 as shown in Figure 4 to Figure 5 , that is, applicable to the wafer slicing machine 100 in which the wire passing wheel 30 is installed on the translation mechanism 50, the translation mechanism 50 is slidably connected to the machine body 10, and the tension driving member 70 is drivingly connected to the translation mechanism 50 and used to drive the translation mechanism 50 to translate. The tension driving member 70 in the wafer slicing machine 100 can adopt a push rod motor, and the push rod motor drives the translation mechanism 50 to move in a uniform straight line.

[0070] Specifically, in Embodiment 1, the relational expression between the tension T of the cutting wire 60 and the position p of the wire passing wheel 30 T(p) is:

[0071] T = where p = θ;

[0072] The activity amount Δ should be adjusted p = Δθ = (θ2 - θ1),

[0073] where θ is the swing angle of the adjusting swing arm 40, and also represents the angular position of the adjustment target. θ2 is the angular position when the adjustment target completes tensioning, and is also equal to the angle of the adjusting swing arm 40 when the adjustment target completes tensioning. θ1 is the angular position when the adjustment target is determined to be abnormal at the abnormal cutting line 60, and is also equal to the angle of the adjusting swing arm 40 when the adjustment target is determined to be abnormal at the abnormal cutting line 60. τ is the output torque of the rotating motor, L is the distance from the rotation center of the adjustment target to the revolution center 42 of the adjustment target. The rotation center of the adjustment target is the axis of the adjustment target, and is also the first rotation center 41 of the adjusting swing arm 40 where the adjustment target is located.

[0074] In some embodiments, the angular range of the adjusting swing arm 40 rotating around the revolution center 42 is 20°. As Figure 3 shown, -10° ≤ θ ≤ 10°, and θ increases as the adjustment target moves away from the winding roller shaft 20. Figure 3 Among them, when the wire guiding wheel 30 on the left side of the winding roller shaft 20 rotates clockwise around the revolution center 42, it approaches the winding roller shaft 20, making the cutting line 60 tend to be slack. When it rotates counterclockwise, it moves away from the winding roller shaft 20, increasing the tension of the cutting line 60. When the wire guiding wheel 30 on the right side of the winding roller shaft 20 rotates counterclockwise around the revolution center 42, it approaches the winding roller shaft 20, making the cutting line 60 tend to be slack. When it rotates clockwise, it moves away from the winding roller shaft 20, increasing the tension of the cutting line 60. When the first rotation center 41 of the adjustment target is vertically above the revolution center 42, θ = 0°. Figure 3 Among them, the wire guiding wheel 30 presented in solid line contour exactly corresponds to the case of θ = 0°. The first rotation center 41 of the adjustment target and the revolution center 42 of the adjustment target are located in the same vertical plane. The dashed line contour represents the limit position of the wire guiding wheel 30 rotating around the revolution center 42.

[0075] In the second embodiment, the relationship between the tension T of the cutting line 60 and the position p of the wire guiding wheel 30 T(p) is:

[0076] T = K w ·( - L0), p = (S, 0);

[0077] The activity amount Δ should be adjusted p = Δ S = - ,

[0078] Among them, the rotation center of the adjustment target is the second rotation center 51 of the wire passing wheel 30. The rotation center of the adjustment target is parallel to the axis of the winding roller shaft 20. The wire passing wheel 30 is driven by the tension driving member 70 to linearly translate horizontally in a plane perpendicular to the axial direction of the winding roller shaft 20. A plane rectangular coordinate system ZOY as shown in Figure 4 to Figure 5 is established. The Z-axis direction is the vertical direction, the Y-axis direction is the horizontal direction, the YOZ plane is perpendicular to the axes of the winding roller shaft 20 and the wire passing wheel 30. (S, 0) is an ordered pair located on the Y-axis in the ZOY coordinate system, and this pair represents the position of the axis of the wire passing wheel 30. S is the horizontal coordinate of the second rotation center 51 of the adjustment target. The translation direction of the adjustment target within the preset adjustment interval is always perpendicular to the second rotation center 51 of the adjustment target and always parallel to the Y-axis direction. Δ S is the translation amount of the adjustment target within the preset adjustment interval. Δ S is equivalent to the moving amount of the wire passing wheel 30 driven by the tension driving member 70 to translate horizontally during the period from the start of tensioning the cutting wire 60 to the completion of tensioning the cutting wire 60. As shown in Figure 4 to Figure 5 , the preset adjustment interval is a horizontal interval. The starting abscissa and the ending abscissa of this horizontal interval are a and b respectively. (a, 0) and (b, 0) respectively represent the projection points of the starting point and the ending point of the preset adjustment interval on the Y-axis. The relationship among a, b, and S always satisfies a ≤ S ≤ b. The second rotation center 51 of the wire passing wheel 30 is always moving within the preset adjustment interval. K w is the known elastic coefficient of the cutting wire 60, L0 is the initial routing length of the cutting wire 60, H is the offset distance from the top of the adjustment target, and H remains unchanged when the wire passing wheel 30 is driven by the tension driving member 70 to translate.

[0079] Refer to Figure 4 to Figure 5 . The initial routing length L0 refers to: the length of the straight line segment of the cutting wire 60 passing through the wire passing wheel 30 at the initial position and the top winding roller shaft 20 closest to the wire passing wheel 30 at the initial position. Due to the initial tension of the cutting wire 60, the part of the cutting wire 60 passing through the wire passing wheel 30 at the initial position and the top winding roller shaft 20 closest to the wire passing wheel 30 at the initial position is a straight line and is tangent to the wire passing wheel 30 at the initial position and the top winding roller shaft 20 closest to the wire passing wheel 30 at the initial position.

[0080] Figure 4 to Figure 5In the slicing machine shown, the number of winding roller shafts 20 is three, and the three winding roller shafts 20 are arranged axially parallel. When observing the slicing machine 100 along the axial direction of the winding roller shafts 20, the center line connection of the three winding roller shafts 20 forms a triangle. In the figure, the three winding roller shafts 20 are the first winding roller shaft 21, the second winding roller shaft 22, and the third winding roller shaft 23 in sequence. The distance from the first winding roller shaft 21 to the ground is less than the distance from the second winding roller shaft 22 to the ground, and the distance from the first winding roller shaft 21 to the ground is less than the distance from the third winding roller shaft 23 to the ground. Figure 4 to Figure 5 The third winding roller shaft 23 located in the upper right in it is the top winding roller shaft 20 closest to the wire passing wheel 30 at the initial position; the wire passing wheel 30 at the initial position is the wire passing wheel 30 when the abscissa of the second rotation center 51 is equal to a and it is located at the starting point of the preset adjustment interval.

[0081] See Figure 4 to Figure 5 , the two winding roller shafts 20 that are farther from the ground are both used as the top winding roller shafts 20, and the sides of the two top winding roller shafts 20 facing away from the ground are at the same height and are both higher than the side of the wire passing wheel 30 facing away from the ground. The top offset distance H of the adjustment target refers to the distance between the horizontal plane where the axis of the wire passing wheel 30 is located and the highest tangent plane of the top winding roller shaft 20 closest to the wire passing wheel 30 at the initial position. The highest tangent plane is a horizontal plane and is tangent to the side of the top winding roller shaft 20 facing away from the ground. The wire passing wheel 30 moves horizontally within the preset adjustment interval, and the axis of the winding roller shaft 20 is fixed. Therefore, the top offset distance H of the adjustment target remains unchanged all the time. In Figure 4 to Figure 5 In the ZOY rectangular coordinate system shown, the top offset distance H of the adjustment target = (ordinate of the axis of the top winding roller shaft 20 closest to the wire passing wheel 30 at the initial position) + (radius of the top winding roller shaft 20 closest to the wire passing wheel 30 at the initial position) - (ordinate of the second rotation center 51).

[0082] In other embodiments, the number of winding roller shafts 20 can also be two. When the two winding roller shafts 20 are arranged horizontally at intervals, the top offset distance H of the adjustment target is the distance between the horizontal plane where the axis of the wire passing wheel 30 is located and the highest tangent plane of the winding roller shaft 20 closest to the wire passing wheel 30 at the initial position.

[0083] Specifically, in Figure 4 to Figure 5In the plane rectangular coordinate system ZOY shown, the Z-axis passes through and is perpendicular to the axis of the top winding roller shaft 20 closest to the wire guiding pulley 30 at the initial position. The Y-axis passes through the axis of the wire guiding pulley 30, that is, the Y-axis is perpendicular to the second rotation center 51. Therefore, when the axis of the wire guiding pulley 30 moves to the starting point of the preset adjustment interval, the coordinates of the second rotation center 51 are (a, 0); when the axis of the wire guiding pulley 30 moves to the end point of the preset adjustment interval, the coordinates of the second rotation center 51 are (b, 0). The movement trajectory of the second rotation center 51 is the line connecting (a, 0) and (b, 0). The second rotation center 51 translates along the Y-axis and keeps the ordinate equal to 0. Therefore, in Figure 4 to Figure 5 In the plane rectangular coordinate system ZOY shown, the top offset H of the adjustment target = (ordinate of the axis of the top winding roller shaft 20 closest to the wire guiding pulley 30 at the initial position) + (radius of the top winding roller shaft 20 closest to the wire guiding pulley 30 at the initial position), Δp = ΔS = S - a, where S is numerically equal to the abscissa of the second rotation center 51 in the rectangular coordinate system ZOY.

[0084] S increases as the tension driving member 70 drives the adjustment target away from the winding roller shaft 20 and decreases as the tension driving member 70 drives the adjustment target closer to the winding roller shaft 20. Figure 4 to Figure 5 In the slicing machine 100 shown, when the wire guiding pulley 30 on the right side of the winding roller shaft 20 translates in the positive Y-axis direction, it moves away from the winding roller shaft 20, thereby increasing the tension of the cutting wire 60. When the wire guiding pulley 30 translates in the negative Y-axis direction, it moves closer to the winding roller shaft 20, thereby making the cutting wire 60 tend to be slack. Figure 5 The wire guiding pulley 30 presented in solid outline in satisfies S =

[0085] The positions of the wire guiding pulley 30 when S = a and S = b are respectively represented by the dotted outline on the left side of the solid outline and the dotted outline on the right side of the solid outline, that is, the two dotted outlines respectively represent the situations where the wire guiding pulley 30 follows the translation mechanism 50 to translate to the limit positions.

[0086] Those of ordinary skill in the art of this technology should recognize that the above embodiments are only used to illustrate the present invention, rather than to limit the present invention. As long as appropriate changes and variations are made to the above embodiments within the scope of the spirit of the present invention, they fall within the scope of protection required by the present invention.

Claims

1. A method for adjusting the tension of a wafer cutting wire, characterized in that, The slicing machine for performing the tension adjustment method of the wafer cutting line includes a machine body (10), a plurality of winding roller shafts (20) and wire passing wheels (30). The winding roller shafts (20) are rotatably arranged on the machine body (10). The tension adjustment method of the wafer cutting line includes: A. Monitoring the wafer thickness and / or the tension of the cutting line (60), and determining the abnormal cutting line; B. According to ΔT adjust = K1·ΔH + K2·(T target - T current ), the tension adjustment compensation amount ΔT of the abnormal cutting line is obtained adjust , K1 is the thickness deviation weight coefficient, K2 is the tension attenuation weight coefficient, ΔH is the thickness deviation of the wafer cut in the previous pass, T target is the target tension for this cut, T current is the tension when the abnormal cutting line is determined to be abnormal; C. Using the thread guide pulley (30) bypassed by the abnormal cutting line as the adjustment target, according to the relationship between the tension T of the cutting line (60) and the position p of the thread guide pulley (30) T(p) Determine the amount of adjustment Δ of the adjustment target p , and drive the adjustment target according to the amount of adjustment Δ p until the adjusted tension T of the abnormal cutting line adjust satisfies T adjust -T current =ΔT adjust at which time the tensioning is completed; Wherein: The slicing machine for performing the tension adjustment method of the wafer cutting line further includes an adjusting swing arm (40). One end of the adjusting swing arm (40) is hinged to the machine body (10), and the wire passing wheel (30) is rotatably installed at the other end of the adjusting swing arm (40). The axis of the wire passing wheel (30) and the rotation center of the adjusting swing arm (40) respectively form the self-rotation center and the revolution center of the wire passing wheel (30). The end of the adjusting swing arm (40) where the wire passing wheel (30) is installed allows the wire passing wheel (30) to rotate self, and the wire passing wheel (30) revolves relative to the machine body (10). Relationship between the tension T of the cutting line (60) and the position p of the thread guide pulley (30) T(p) is as follows: , p = θ; The activity amount Δ should be adjusted p = Δθ = (θ2 - θ1), θ2 is the angular position when the adjustment target completes tensioning, θ1 is the angular position of the adjustment target when the abnormal cutting line is determined to be abnormal, τ is the output torque of the rotating motor, and L is the distance from the self-rotation center of the adjustment target to the revolution center of the adjustment target. Or, The slicing machine for performing the tension adjustment method of the wafer cutting line further includes a translation mechanism (50). The wire passing wheel (30) is rotatably installed on the translation mechanism (50), and the translation mechanism (50) is slidably connected to the machine body (10). The position where the wire passing wheel (30) is installed on the translation mechanism (50) and the axis of the wire passing wheel (30) form the self-rotation center of the wire passing wheel (30). Relationship between the tension T of the cutting line (60) and the position p of the line passing wheel (30) T(p) is as follows: , p = (S, 0); The activity amount Δ should be adjusted p = Δ S = , S is the horizontal position coordinate of the rotation center of the adjustment target, Δ S is the translation amount of the adjustment target within the preset adjustment range, K w is the elastic coefficient of the cutting line (60), L0 is the initial length of the cutting line (60) when it is routed, and H is the offset distance from the top of the adjustment target.

2. The method for adjusting the tension of the wafer cutting line according to claim 1, wherein, The self-rotation center and the revolution center of the adjustment target are both parallel to the axis of the winding roller shaft (20). - 10° ≤ θ ≤ 10°, θ increases as the adjustment target moves away from the winding roller shaft (20). When the self-rotation center of the adjustment target is vertically above the revolution center, θ = 0°.

3. The method for adjusting the tension of the wafer cutting line according to claim 1, wherein The self-rotation center of the adjustment target is parallel to the axis of the winding roller shaft (20), and the translation direction of the adjustment target within the preset adjustment range is perpendicular to the self-rotation center of the adjustment target. a ≤ S ≤ b, and S increases as the adjustment target moves away from the winding roller shaft (20).

4. The method for adjusting the tension of the wafer cutting line according to claim 1, wherein, The slicing machine for performing the tension adjustment method of the wafer cutting line further includes a tension driving member (70). The tension driving member (70) is drivingly connected to the adjusting swing arm (40).

5. The method for adjusting the tension of the wafer cutting line according to claim 4, wherein, The axis of the winding roller shaft (20), the axis of the wire passing wheel (30) and the rotation center of the adjusting swing arm (40) are parallel to each other. The tension driving member (70) is used to drive the wire passing wheel (30) to move away from the winding roller shaft (20), so as to increase the tension of the cutting line (60) bypassing the wire passing wheel (30); and / or, The wire passing wheel (30) includes a middle wire passing wheel. The winding roller shaft (20) has a winding section extending along the axial direction. The two ends of the winding section are equidistant from the opposite sides of the middle wire passing wheel.

6. The method for adjusting the tension of the wafer cutting line according to claim 1, wherein, The slicing machine for performing the tension adjustment method of the wafer cutting line further includes a tension driving member (70). The tension driving member (70) is drivingly connected to the translation mechanism (50).

7. The method for adjusting the tension of the wafer cutting wire according to claim 6, wherein, The axis of the winding roller shaft (20) is parallel to the axis of the wire passing wheel (30), and the translation mechanism (50) forms a moving pair with the machine body (10) so that the translation mechanism (50) translates in a direction perpendicular to the axis of the wire passing wheel (30). The tension driving member (70) is used to drive the wire passing wheel (30) to move away from the winding roller shaft (20), so as to increase the tension of the cutting wire (60) bypassing the wire passing wheel (30); and / or, The winding roller shaft (20) includes a top winding roller shaft, and the side of the top winding roller shaft facing away from the ground is higher than the side of the wire passing wheel (30) facing away from the ground; and / or, The wire passing wheel (30) includes a middle wire passing wheel, the winding roller shaft (20) has a winding section extending along the axial direction, and the two ends of the winding section are equidistant from the opposite sides of the middle wire passing wheel.

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