Crystal rod slicing processing method and wire cutting machine

Abstract

This invention provides a method for slicing crystal rods and a wire cutting machine. The method includes: monitoring the actual wire bow value g during the slicing process and determining the wire bow difference Δh based on the ideal wire bow value H-cut depth Y image, where Δh = H - g; during the first slicing period, if Δh is negative, a supplementary adjustment is made to increase the cutting force of the wire mesh; if Δh is greater than 0.5 mm, a weakening adjustment is made to reduce the cutting force of the wire mesh, so that the wire bow difference Δh falls within the range of 0~0.5 mm; during the second slicing period, if Δh is negative, the reciprocating motion stroke between the crystal rod and the wire mesh is increased; if Δh is positive, the reciprocating motion stroke is decreased.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a method for slicing crystal rods and a wire cutting machine. Background Technology

[0002] Wire cutting machines and dicing wire meshes are used to slice crystal ingots, requiring consistent wafer surface accuracy and quality. Defects in the crystal ingot itself, the performance of the dicing wire mesh, and the quality of the abrasive can all affect the cutting force of the dicing wire mesh, leading to abnormal wafer surface shapes. Current slicing processes cannot effectively and promptly adjust for abnormal cutting forces caused by crystal ingot defects, dicing wire mesh issues, or abrasive abnormalities during the slicing process; the causes of non-compliant wafer surface shapes can only be identified after slicing is completed by examining the surface shapes of defective wafers. Summary of the Invention

[0003] In view of this, the present invention provides a crystal rod slicing processing method and a wire cutting machine. The crystal rod slicing processing method and wire cutting machine of the present invention enable timely and effective adjustment of the cutting force of the cutting wire mesh during the cutting process, thereby obtaining wafers with high-quality surface profiles.

[0004] The crystal rod slicing method of the present invention includes:

[0005] During the cutting of the crystal rod, the actual arc value g is monitored, and the arc difference Δh is determined based on the ideal arc value H-cut depth Y image, where Δh = H - g;

[0006] During the first cutting period, if Δh is negative, a supplementary adjustment is made to increase the cutting force of the cutting wire mesh; if Δh is greater than 0.5 mm, a weakening adjustment is made to reduce the cutting force of the cutting wire mesh, so that the wire bow difference Δh falls into the range of 0~0.5 mm.

[0007] During the second cutting period, if Δh is negative, the reciprocating motion stroke between the crystal rod and the cutting wire mesh is increased; if Δh is positive, the reciprocating motion stroke is decreased.

[0008] The crystal rod slicing method and slicing machine of the present invention have the following beneficial effects:

[0009] 1) To compensate for insufficient cutting force caused by crystal rod defects, increase the reciprocating stroke of the crystal rod and the cutting wire mesh to compensate for insufficient cutting force caused by abnormal auxiliary materials.

[0010] 2) Reduce the cutting force to reduce excess cutting force caused by crystal rod defects and reduce the reciprocating motion stroke between the crystal rod and the cutting wire mesh. Reduce the cutting force to reduce excess cutting force caused by abnormal auxiliary materials.

[0011] 3) The adverse effects of defects in the crystal ingot itself on the wafer surface shape, as well as the adverse effects of abnormal auxiliary materials on the wafer surface shape, can be offset by adjusting the cutting force and reciprocating motion stroke in real time. This allows the cutting wire mesh to approach the optimal cutting state and the cutting process to adapt to occasional and variable crystal ingot defects and auxiliary material abnormalities. When the method of this invention is implemented during formal wafer production, high-quality wafers with good surface shapes can be obtained without the need for crystal trial cutting operations, reducing the waste and loss of crystal materials and diamond wires, and reducing the cost of crystal trial cutting.

[0012] In some implementations, supplementary adjustment includes decreasing the feed rate V, and weakening adjustment includes increasing the feed rate V; the feed rate after performing supplementary adjustment and / or weakening adjustment is V', and the feed rate before performing supplementary adjustment and / or weakening adjustment is V0. .

[0013] In some implementations, the supplementary adjustment further includes increasing the amount of new lines T per cycle, and the weakening adjustment further includes decreasing the amount of new lines T per cycle. The amount of new lines per cycle after performing the supplementary adjustment and / or weakening adjustment is T', and the amount of new lines per cycle before performing the supplementary adjustment and / or weakening adjustment is T0. .

[0014] In some implementations, if 0 ≤ Δh ≤ 0.5 mm during the first cutting period, the cutting parameters are maintained, including the feed rate V and the amount of new wire per cycle T, until Δh becomes negative or greater than 0.5 mm.

[0015] In some implementations, during the first cutting period, the actual bow value g is monitored every 5 to 15 minutes to determine the bow difference Δh, and then a supplementary adjustment, a weakening adjustment, or a maintenance cutting parameter is performed every 5 to 15 minutes based on the bow difference Δh.

[0016] In some embodiments, increasing the reciprocating stroke includes increasing the swaying amplitude α of the crystal rod relative to the dicing wire mesh; decreasing the reciprocating stroke includes decreasing the swaying amplitude α of the crystal rod relative to the dicing wire mesh.

[0017] In some implementations, the method further includes:

[0018] During the second cutting period, if Δh is negative, the feed / retraction amount N of the crystal is increased; if Δh is positive, the feed / retraction amount N of the crystal is decreased.

[0019] In some implementations, the feed retraction amount N is not greater than the maximum feed retraction amount Y1.

[0020] Y is the current cutting depth, r is the radius of the crystal rod, and α is the adjusted rocking angle.

[0021] In some implementations, the maximum change in the swing amplitude α is 0.5°.

[0022] In some implementations, the method further includes:

[0023] During the second cutting period, if Δh is negative, a supplementary adjustment is made; if Δh is greater than 0.5 mm, a weakening adjustment is made; if 0 ≤ Δh ≤ 0.5 mm, the feed rate V and the amount of new wire per cycle T are kept constant until Δh becomes negative or greater than 0.5 mm.

[0024] In some implementations, the total duration of the first segment is 20 to 40 minutes, and the second segment begins after the end of the first segment.

[0025] The wire cutting machine of the present invention is used to perform the above method, and the wire cutting machine includes:

[0026] The wire mesh conveying unit includes a spool for releasing and winding diamond wire and multiple rollers for conveying the diamond wire and forming a cut wire mesh.

[0027] The crystal control unit includes a feeding device, a reciprocating device, and a crystal carrier. The feeding device is configured to move up and down relative to the cutting wire mesh. The reciprocating device is movably connected to the feeding device, and the crystal carrier is movably disposed on the reciprocating device.

[0028] The pantograph monitoring unit is used to monitor the actual pantograph value when the wire mesh is cut;

[0029] The parameter adjustment unit includes a feed control module, a reciprocating control module, and a wire supply control module that are communicatively connected to the pantograph monitoring unit; wherein, the feed device is controlled and connected to the feed control module, the reciprocating device is controlled and connected to the reciprocating control module, and the spool and roller are controlled and connected to the wire supply control module. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a wire cutting machine according to one embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram showing the relative positions of the diamond wire and the crystal rod during the wire cutting process.

[0032] Figure 3 An image of the actual arc value-cut depth obtained for implementing the crystal rod slicing method of the present invention.

[0033] Explanation of reference numerals in the attached drawings: 10, crystal rod; 20, cutting wire mesh; 21, first inclined section; 22, second inclined section; 23, turning connection section; 30, wire roller; 41, feeding device; 42, reciprocating device; 43, crystal carrier; 50, wire bow monitoring unit; 60, parameter adjustment unit; 61, feed control module; 62, reciprocating control module; 63, wire supply control module. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0036] This invention provides a method for slicing crystal rods and a wire cutter for performing this method. By using a cutting wire mesh 20 formed by diamond wire in conjunction with the wire cutter, the crystal rod slicing method of this invention is performed, thereby cutting an entire crystal rod 10 into multiple wafers.

[0037] With the slicing process optimized and determined, the sources of wafer surface defects include defects in the crystal rod 10 itself and abnormalities in the auxiliary materials. Defects in the crystal rod 10 itself are crystal material defects generated during the growth of the crystal raw material into the crystal rod 10. Abnormalities in the auxiliary materials include a decrease in the quality of diamond wire abrasive, uneven abrasive agglomeration in slurry or other working fluids, and abnormally low diamond wire cutting edge rate.

[0038] Current slicing processes pre-set process parameters such as cutting force for the cutting wire mesh before cutting the crystal ingot, and investigate the causes of defects based on wafer surface defects after cutting. However, defects in the crystal ingot itself and abnormalities in auxiliary materials are uncertain and sporadic, making them difficult to predict in advance and identify in real time. The severity of abnormalities varies between different batches of crystal ingots and different cutting auxiliary materials (diamond wire and working fluid). Even among crystal ingots in the same batch, it is difficult to guarantee that the crystal material properties of each ingot are uniform. Even if the process parameters are adjusted before cutting, it is difficult to guarantee that all crystal ingots will eventually form high-quality wafers with uniform surface quality.

[0039] Therefore, the crystal rod slicing processing method of the present invention includes the following steps:

[0040] Step A: During the cutting of the crystal rod 10, monitor the actual arc value g, and determine the arc difference Δh based on the ideal arc value H-cut depth Y image, where Δh = H - g;

[0041] Step B: During the first cutting period, if Δh is negative, a supplementary adjustment is made to increase the cutting force of the cutting wire mesh 20; if Δh is greater than 0.5 mm, a weakening adjustment is made to reduce the cutting force of the cutting wire mesh 20, so that the wire bow difference Δh falls within the range of 0~0.5 mm.

[0042] Step C: During the second cutting period, if Δh is negative, the reciprocating motion stroke between the crystal rod 10 and the cutting wire mesh 20 is increased; if Δh is positive, the reciprocating motion stroke is decreased.

[0043] The first cutting period and the second cutting period are two different periods in the crystal rod 10 cutting process, and these two periods do not overlap.

[0044] In some implementations, the total duration of the first cutting period is 20 to 40 minutes, and the second cutting period begins after the end of the first cutting period;

[0045] Preferably, the total duration of the first cutting period is 30 minutes, and the second cutting period begins immediately after the 30-minute cutting process of the crystal rod 10 is completed.

[0046] See Figure 1 The wire cutting machine of the present invention includes a wire mesh conveying unit, a crystal control unit, a wire bow monitoring unit 50, and a parameter adjustment unit 60, wherein:

[0047] The wire mesh conveying unit includes a spool (not shown) and multiple rollers 30 for conveying diamond wire and forming the cutting wire mesh 20. The spool includes a feed spool for releasing the diamond wire and a take-up spool for winding the diamond wire. The diamond wire is wound around the multiple rollers 30 to form the cutting wire mesh 20. Figure 1 The horizontal dashed line Q, which is tangent to both wire rollers 30, represents a portion of the cutting wire mesh 20 that does not contact the crystal rod 10, and the V-shaped broken line below the horizontal dashed line represents a portion of the cutting wire mesh 20 that contacts the crystal rod 10.

[0048] The crystal control unit includes a feeding device 41, a reciprocating device 42, and a crystal carrier 43. The feeding device 41 is configured to move up and down relative to the dicing mesh 20. The reciprocating device 42 is movably connected to the feeding device 41. The crystal carrier 43 is movably disposed on the reciprocating device 42. The crystal carrier 43 can carry the crystal ingot 10 so that the crystal ingot 10 and the crystal carrier 43 follow the reciprocating device 42 in reciprocating motion relative to the dicing mesh 20. The reciprocating device 42, the crystal carrier 43, and the crystal ingot 10 move up and down together relative to the dicing mesh 20 under the drive of the feeding device 41. The reciprocating motion of the crystal ingot 10 relative to the dicing mesh 20 includes a horizontal component, which is parallel to the horizontal axis. Figure 1The horizontal dashed line Q is shown; the movement of the crystal rod 10 driven by the feeding device 41 to approach the cutting wire mesh 20 and reach the space between the two wire rollers 30 is called the feeding motion, the speed of the feeding motion is called the feeding speed, the amount of downward movement of the crystal rod 10 along the vertical direction of the horizontal dashed line Q caused by the feeding motion is called the feeding stroke, and the cutting wire mesh 20 gradually cuts the crystal rod 10 through the feeding motion.

[0049] The pantograph monitoring unit 50 is used to monitor the actual pantograph value of the cut wire mesh 20. Figure 1 The V-shaped zigzag line located below the horizontal dotted line includes a first inclined segment, a second inclined segment, and a turning connection segment 23. The first inclined segment 21 and the second inclined segment 22 form an angle and are tangent to the two wire rollers 30 respectively. The turning connection segment 23 connects the first inclined segment 21 and the second inclined segment 22 and contacts the crystal rod 10. The distance from the first inclined segment 21 to the horizontal dotted line increases in the direction closer to the turning connection segment 23. The distance from the second inclined segment 22 to the horizontal dotted line also increases in the direction closer to the turning connection segment 23. The maximum distance from the horizontal dotted line to the turning connection segment 23 is the actual wire bow value.

[0050] The parameter adjustment unit 60 includes a feed control module 61, a reciprocating control module 62, and a wire supply control module 63, all communicatively connected to the pantograph monitoring unit 50. The feed device 41 is controlled and connected to the feed control module 61, the reciprocating device 42 is controlled and connected to the reciprocating control module 62, and the bobbin and roller 30 are controlled and connected to the wire supply control module 63. The feed control module 61 controls the feed speed and feed stroke of the feed device 41. The feed device 41 drives the reciprocating device 42, the crystal carrier 43, and the crystal rod 10 to move relative to the cutting wire mesh 20 at a feed speed V. The feed stroke is equal to the distance between the reciprocating device 42, the crystal carrier 43, and the crystal rod 10 perpendicular to the wire mesh 20. Figure 1 The displacement is indicated by the horizontal dashed line; the reciprocating control module 62 controls the distance between the two reciprocating positions of the reciprocating device 42, thereby controlling the reciprocating stroke of the crystal rod 10 and the cutting wire mesh 20. The greater the distance between the two reciprocating positions of the reciprocating device 42, the greater the reciprocating stroke; the wire supply control module 63 can control the conveying length of the cutting wire mesh 20, thereby adjusting the amount of new wire in a single cycle.

[0051] The ideal arc value H-cut depth Y graph is a function graph with cut depth Y as the abscissa and independent variable, and ideal arc value H as the ordinate and dependent variable. Cut depth Y, also known as the entry position, is a function of time. Cut depth Y can be represented by the distance from the turning connection segment 23 to the initial cutting position. The initial cutting position is the generatrix of the cutting wire mesh 20 that first contacts the outer periphery of the crystal rod 10. Before the crystal rod 10 contacts the cutting wire mesh 20, the cutting wire mesh 20 and... Figure 1 The horizontal dashed line Q coincides with the initial cutting position. Figure 1 The distance of the horizontal dashed line Q is from the outer periphery of the crystal rod 10 to... Figure 1 The shortest distance to the horizontal dashed line Q.

[0052] The crystal ingot slicing method and wire cutting machine of the present invention can adjust the cutting force of the cutting wire mesh 20 and the reciprocating stroke between the cutting wire mesh 20 and the crystal ingot 10 in real time as needed during the crystal ingot 10 cutting process. This effectively and promptly counteracts the adverse effects of defects in the crystal ingot 10 itself and abnormalities in auxiliary materials on the wafer surface, bringing the cutting wire mesh 20 to the optimal cutting state and adapting the cutting process to the occasional and variable defects in the crystal ingot 10 and abnormalities in auxiliary materials, thereby obtaining wafers with high-quality surface shapes. There is no need to adjust the cutting process steps, nor is it necessary to perform crystal trial cutting operations before formal wafer production, reducing the waste of crystal materials and diamond wire.

[0053] If Δh is negative during the first cutting period, it indicates that the cutting force of the cutting wire mesh 20 is insufficient. The supplementary adjustment is intended to compensate for the insufficient cutting force caused by defects in the crystal rod 10 itself, and to prevent phenomena such as abnormal wafer thickness, cutting interruption, and kerf offset.

[0054] If Δh is greater than 0.5 mm during the first cutting period, it indicates that the cutting force of the cutting wire mesh 20 is excessive. The weakening adjustment is intended to reduce the cutting force caused by the defects of the crystal rod 10 itself, so as to prevent defects such as bumps, wavy lines, and reduced smoothness on the wafer cutting surface. In addition, the weakening adjustment can also reduce the probability of the diamond wire breaking due to excessive tension.

[0055] During the second cutting period, a negative Δh indicates that the cutting force of the cutting wire mesh 20 needs to be increased. Increasing the reciprocating stroke of the crystal rod 10 and the cutting wire mesh 20 can improve chip removal efficiency, accelerate the removal of crystal chips from the cut of the crystal rod 10, avoid the accumulation of crystal chips which would limit the effect of diamond wire abrasive grinding the crystal rod 10, and at the same time offset the adverse effects caused by the low diamond wire cutting edge rate. In addition, a larger reciprocating stroke can promote the flow of working fluid relative to the crystal rod 10 and the diamond wire, which helps the working fluid to carry away more frictional heat and prevent the cutting efficiency from decreasing due to local overheating of the diamond wire.

[0056] During the second cutting period, the appearance of a positive value for Δh indicates that the cutting force of the cutting wire mesh 20 has exceeded the requirements of the cutting process. Reducing the reciprocating motion stroke of the crystal rod 10 and the cutting wire mesh 20 can maintain the shape of the wire bow, suppress the jitter amplitude of the cutting wire mesh 20, help reduce the TTV value of the wafer, which is the total thickness deviation, and also reduce the probability of diamond wire breakage.

[0057] The cutting force is adjusted during the first cutting period to adapt the cutting process to the defects of the crystal rod 10 itself. During the second cutting period, the reciprocating stroke of the crystal rod 10 and the cutting wire mesh 20 is changed according to the wire bow difference Δh to adapt the cutting process to the abnormality of the auxiliary material. Finally, the cutting wire mesh 20 is ensured to tend to the optimal cutting state, thus realizing the dynamic adaptation of the cutting process to the occasional and varied defects of the crystal rod 10 and the abnormality of the auxiliary material.

[0058] In some embodiments, the ingot slicing method further includes:

[0059] Step D: During the first cutting period, if 0 ≤ Δh ≤ 0.5 mm, the cutting parameters are maintained. Maintaining the cutting parameters includes maintaining the feed speed V and maintaining the amount of new wire per cycle T, until Δh becomes negative or greater than 0.5 mm. After Δh becomes negative or greater than 0.5 mm, the cutting force of the cutting wire mesh 20 is adjusted according to the aforementioned step B.

[0060] Furthermore, during the first cutting period, the actual bow value g is monitored every 5 to 15 minutes to determine the bow difference Δh, and then every 5 to 15 minutes, the supplementary adjustment or the weakening adjustment or the maintenance cutting parameters are performed based on the bow difference Δh.

[0061] With this setup, the monitoring interval of the actual bow value g divides the first cutting period into multiple parameter adjustment periods. During each parameter adjustment period, the cutting force is adjusted multiple times to ensure that the cutting state of the cutting wire mesh 20 reaches its optimal state within each parameter adjustment period.

[0062] Preferably, during the first cutting period, the actual bow value g is monitored every 10 minutes to determine the bow difference Δh, and then every 10 minutes the supplementary adjustment or the weakening adjustment or the maintaining cutting parameters are performed based on the bow difference Δh.

[0063] In some implementations, supplementary adjustment includes reducing the feed rate V, and weakening adjustment includes increasing the feed rate V. The feed rate after performing supplementary adjustment and / or weakening adjustment is V', and the feed rate before performing supplementary adjustment and / or weakening adjustment is V0. .

[0064] Specifically, during each parameter adjustment period, the pantograph monitoring unit 50 first monitors the actual pantograph value g, then calculates the pantograph difference Δh based on the ideal pantograph value H - cutting depth Y function. Next, the feed control module 61 adjusts the feed speed of the feed device 41 according to the pantograph difference Δh, so that the feed speed meets the requirements for the remaining time of the current parameter adjustment period. .

[0065] The supplementary adjustment also includes increasing the amount of new lines per cycle T, and the weakening adjustment also includes decreasing the amount of new lines per cycle T. The amount of new lines per cycle after performing the supplementary adjustment and / or weakening adjustment is T´, and the amount of new lines per cycle before performing the supplementary adjustment and / or weakening adjustment is T0. The increase and decrease of the amount of new wire T in a single cycle are achieved by controlling the wire network conveying unit through the wire supply control module 63.

[0066] It should be noted that in the actual execution of the ingot slicing process, the feed speed can be adjusted solely through the feed control module 61, or the amount of new wire per cycle can be adjusted solely through the wire supply control module 63, or both the feed speed and the amount of new wire per cycle can be adjusted simultaneously. Adjusting the amount of new wire per cycle solely through the wire supply control module 63 does not require changing the feed speed; it is only necessary to adjust according to... Calculate the feed rate V', then substitute the feed rate V0 and the feed rate V' into the equation. That's all.

[0067] In some embodiments, increasing the reciprocating stroke in step C includes increasing the swaying amplitude α of the crystal rod 10 relative to the dicing wire mesh 20; decreasing the reciprocating stroke includes decreasing the swaying amplitude α of the crystal rod 10 relative to the dicing wire mesh 20; therefore, step C specifically includes:

[0068] Step C1: During the second cutting period, if Δh is negative, the swing amplitude α of the crystal rod 10 relative to the cutting wire mesh 20 is increased; if Δh is positive, the swing amplitude α is decreased.

[0069] The reciprocating motion between the crystal ingot 10 and the dicing wire mesh 20 is a swinging motion of the crystal ingot 10 relative to the dicing wire mesh 20. The swinging motion is the reciprocating rotation of the crystal ingot 10 around a preset swing center within a preset angle range relative to the dicing wire mesh 20. This preset angle range is the swing amplitude α. Therefore, increasing the swing amplitude α increases the aforementioned preset angle range, and decreasing the swing amplitude α decreases the aforementioned preset angle range.

[0070] In some embodiments, the reciprocating device 42 is a swinging device rotatably connected to the feeding device 41, and the reciprocating control module 62 is a swinging control module that controls the swinging device to generate a swinging motion, so that the crystal rod 10 and the crystal carrier 43 swing with the swinging device. The preset swing center is the axis of the crystal rod 10, and the reciprocating stroke is the angle at which the swinging device swings around the axis of the crystal rod 10. See reference. Figure 2 In the figure, point R represents the axis of the crystal rod 10, which serves as the preset swing center, and ∠α represents the swing amplitude of the crystal rod 10 and the swing device.

[0071] By using a swinging device to drive the crystal rod 10 to swing, the amplitude of the change in diamond wire tension can be prevented from being too large while changing the reciprocating motion stroke, thus reducing the probability of diamond wire breakage. The efficiency of crystal debris being discharged from the cut of the crystal rod 10 is also higher, and crystal debris and diamond wire are less likely to get stuck.

[0072] Furthermore, in some embodiments, the ingot slicing method further includes:

[0073] Step E: During the second cutting period, if Δh is negative, increase the crystal feed / retraction amount N; if Δh is positive, decrease the crystal feed / retraction amount N.

[0074] The feed retraction amount is the amount of displacement by which the feed control module 61 controls the feed device 41 to rise and retract relative to the cutting wire mesh 20. In some crystal ingot cutting processes, the feed device 41 does not continuously lower the crystal ingot 10 during the descent, but rather rises and retracts multiple times during the descent. When the crystal ingot 10 rises and retracts, the depth of the cutting wire mesh 20 embedded in the cut of the crystal ingot 10 decreases. Therefore, the cutting parameters of these crystal ingot cutting processes also include the feed retraction amount. Especially in cutting processes where the crystal ingot 10 swings relative to the cutting wire mesh 20, it is necessary for the feed control module 61 to control the feed device 41 to rise according to the feed retraction amount. The feed retraction amount increases with the increase of the swing amplitude of the crystal ingot 10 because:

[0075] like Figures 1-2 As shown, when the cutting wire mesh 20 cuts the crystal rod 10, the diamond wire located between the two wire rollers 30 forms a V-shaped zigzag. The portion of the V-shaped zigzag within the cut of the crystal rod 10 is called the cutting chord length. The distance from each point on the cutting chord length to the preset swing center increases in a direction away from the turning connection section 23. The dashed line P, tangent to the cutting chord length, is parallel to... Figure 1 The horizontal dashed line Q represents the position of the crystal rod 10 as it oscillates around the preset oscillation center. The position on the oscillation chord that contacts the crystal rod 10 (hereinafter referred to as the wire-cut contact position) repeatedly shifts between the two ends of the oscillation chord. The distance between the dashed line P and the preset oscillation center changes repeatedly, causing the pressure exerted by the crystal rod 10 on the cutting wire mesh 20 to increase, decrease, increase again, and decrease again. This change in pressure from the cutting wire mesh 20 affects the wafer surface profile, making it prone to irregular unevenness on the wafer cross-section. The greater the oscillation amplitude α of the crystal rod 10, the more drastic the change in pressure from the cutting wire mesh 20, resulting in poorer wafer surface quality. If the crystal rod 10 can rise and retreat as it moves away from the turning connection segment 23, the change in distance between the dashed line P and the preset oscillation center will decrease, the change in pressure from the cutting wire mesh 20 will tend to weaken, and the adverse effects of the change in pressure from the cutting wire mesh 20 on the wafer surface profile will tend to be eliminated.

[0076] It is understandable that, in order to prevent the swing amplitude α of the crystal ingot 10 and the changes in the swing amplitude from having an adverse effect on the slicing process and wafer quality, it is necessary to automatically adjust the feed and retraction amount of the crystal ingot 10 during a single swing according to the changes in the swing amplitude α, so as to make the downward pressure of the cutting wire mesh 20 tend to be stable.

[0077] Optionally, the feed retraction amount N is not greater than the preset maximum feed retraction amount Y1.

[0078] Y is the current cutting depth, r is the radius of the crystal rod 10, and α is the adjusted rocking angle after executing step C1.

[0079] Optionally, the maximum change in the swing amplitude α is 0.5°.

[0080] Furthermore, given that the adverse effects of defects in the crystal ingot 10 itself may persist throughout the entire cutting process, in some embodiments, in addition to performing step C described above, the crystal ingot slicing method further includes the following during the second cutting period:

[0081] Step F: During the second cutting period, if Δh is negative, the supplementary adjustment is performed; if Δh is greater than 0.5 mm, the weakening adjustment is performed; if 0 ≤ Δh ≤ 0.5 mm, the feed rate V and the amount of new wire per cycle T are kept constant until Δh becomes negative or greater than 0.5 mm.

[0082] With this setup, during the second cutting period, both the adverse effects of defects in the crystal ingot 10 itself on the wafer quality and the adverse effects of abnormal auxiliary materials on the wafer quality can be offset and overcome by executing step F, thereby obtaining wafers of higher quality.

[0083] The supplementary adjustment during the first dicing period aims to compensate for and strengthen the insufficient cutting force of the dicing mesh 20 caused by defects in the ingot 10 itself, preventing the wafer from developing a wavy surface due to insufficient cutting force. The weakening adjustment during the first dicing period aims to reduce and suppress the excessive cutting force of the dicing mesh 20 caused by defects in the ingot 10 itself, preventing the dicing mesh 20 from wearing down faster due to excessive cutting force, thereby affecting subsequent dicing efficiency and wafer surface quality. In the second dicing period, the swing amplitude of the ingot 10 is increased as a further reinforcement of the supplementary adjustment during the first dicing period, thereby further compensating for and strengthening the cutting force of the dicing mesh 20. In the second dicing period, the swing amplitude of the ingot 10 is decreased as a further reinforcement of the weakening adjustment during the first dicing period, thereby further reducing and suppressing the cutting force of the dicing mesh 20, so that the cutting force of the dicing mesh 20 better meets the dicing requirements of the ingot 10.

[0084] Figure 3The image shows the actual bow value versus cutting depth obtained by implementing the crystal rod slicing processing method of the present invention. The horizontal axis represents the cutting depth and the vertical axis represents the actual bow value. The two bow curves correspond to the cutting processes of the two materials, respectively. As can be seen from the figure, the bow value of the cut wire mesh is more stable and the fluctuation range of the bow value is smaller. The maximum change of the bow value during the cutting process is reduced to 0.15 mm. The stable bow value is beneficial to improving the flatness of the wafer surface, eliminating local bumps and wavy lines on the surface, and reducing the total thickness deviation of the wafer.

[0085] The technical features of the above-described embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0086] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any appropriate changes and variations made to the above embodiments within the essential spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for processing crystal rod slicing, characterized in that, The method includes: During the cutting of the crystal rod, the actual arc value g is monitored, and the arc difference Δh is determined based on the ideal arc value H-cut depth Y image, where Δh = H - g; During the first cutting period, if Δh is negative, a supplementary adjustment is made to increase the cutting force of the cutting wire mesh; if Δh is greater than 0.5 mm, a weakening adjustment is made to reduce the cutting force of the cutting wire mesh, so that the wire bow difference Δh falls into the range of 0~0.5 mm. The supplementary adjustment includes reducing the feed rate V and increasing the amount of new line T per cycle; The weakening adjustment includes increasing the feed rate V and reducing the amount of new wire per cycle T; During the second cutting period, if Δh is negative, the reciprocating motion stroke between the crystal rod and the cutting wire mesh is increased; if Δh is positive, the reciprocating motion stroke is decreased. Increasing the reciprocating motion stroke includes increasing the swaying amplitude α of the crystal rod relative to the cutting wire mesh. Decreasing the reciprocating motion stroke includes decreasing the swaying amplitude α of the crystal rod relative to the cutting wire mesh. and / or, During the second cutting period, if Δh is negative, the feed / retraction amount N of the crystal is increased; if Δh is positive, the feed / retraction amount N of the crystal is decreased.

2. The method for processing crystal rod slicing as described in claim 1, characterized in that, During the first cutting period, if 0 ≤ Δh ≤ 0.5 mm, the cutting parameters are maintained. The maintained cutting parameters include the feed rate V and the amount of new wire per cycle T remaining unchanged until Δh becomes negative or greater than 0.5 mm. and / or, During the first cutting period, the actual bow value g is monitored every 5 to 15 minutes to determine the bow difference Δh. Then, every 5 to 15 minutes, the supplementary adjustment or the weakening adjustment or the maintenance cutting parameters are performed based on the bow difference Δh.

3. The method for processing crystal rod slicing as described in claim 1, characterized in that, The feed retraction amount N is not greater than the maximum feed retraction amount Y1. Y is the current cutting depth, r is the radius of the crystal rod, and α is the adjusted rocking angle.

4. The method for processing crystal rod slicing as described in claim 1, characterized in that, The maximum change in the swing amplitude α is 0.5°.

5. The method for processing crystal rod slicing as described in claim 1, characterized in that, The method further includes: During the second cutting period, if Δh is negative, the supplementary adjustment is performed; if Δh is greater than 0.5 mm, the weakening adjustment is performed; if 0 ≤ Δh ≤ 0.5 mm, the feed rate V and the amount of new wire per cycle T are kept constant until Δh becomes negative or greater than 0.5 mm.

6. The method for processing crystal rod slicing according to any one of claims 1 to 5, characterized in that, The total duration of the first cutting period is 20 to 40 minutes, and the second cutting period begins after the end of the first cutting period.

7. A wire cutting machine, characterized in that, The wire cutter is used to perform the method as described in any one of claims 1 to 6, and the wire cutter comprises: The wire mesh conveying unit includes a spool for releasing and winding diamond wire and multiple wire rollers (30) for conveying diamond wire and forming a cutting wire mesh (20); The crystal control unit includes a feeding device (41), a reciprocating device (42), and a crystal carrier (43). The feeding device (41) is configured to move up and down relative to the cutting wire mesh (20). The reciprocating device (42) is rotatably connected to the feeding device (41), and the crystal carrier (43) is rotatably disposed on the reciprocating device (42). A pantograph monitoring unit (50) is used to monitor the actual pantograph value of the cut wire mesh (20); The parameter adjustment unit (60) includes a feed control module (61), a reciprocating control module (62), and a wire supply control module (63) that are communicatively connected to the pantograph monitoring unit (50); wherein, the feed device (41) is controlled to be connected to the feed control module (61), the reciprocating device (42) is controlled to be connected to the reciprocating control module (62), and the spool and the roller (30) are controlled to be connected to the wire supply control module (63); The feed control module (61) controls the feed speed of the feed device (41), and the feed device (41) drives the reciprocating device (42), the crystal carrier (43) and the crystal rod to move relative to the cutting wire mesh (20) at the feed speed; The reciprocating control module (62) controls the distance between the two reciprocating positions of the reciprocating device (42) to control the reciprocating stroke of the crystal rod and the cutting wire mesh (20).

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