Wire cutting device

Abstract

The invention relates to a wire cutting device which comprises two wire guide wheels arranged oppositely and a cutting wire wound between the two wire guide wheels, a plurality of wire grooves are formed in the peripheral faces of the wire guide wheels, and the cutting wire is wound in the wire grooves. The wire cutting device further comprises at least one cutting wire limiting structure located between the two wire guide wheels, the cutting wire limiting structure comprises limiting holes in one-to-one correspondence with the multiple wire grooves, and the cutting wires penetrate through the limiting holes and are wound in the wire grooves of the wire guide wheels. Through the arrangement of the cutting line limiting structures, the cutting lines are limited in the corresponding line grooves, and abnormal cutting caused by the fact that the cutting lines deviate from the movement track is prevented.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor product manufacturing, and in particular to a wire cutting device. Background Art

[0002] In the semiconductor manufacturing industry, the transformation from crystal ingot to wafer is to cut the crystal ingot into slices using wire cutting equipment. The cutting process uses mortar to continuously spray on the steel wire, and the steel wire carries the mortar to reciprocate to complete the crystal ingot cutting. The movement trajectory of the steel wire is fixed by the wire grooves on the wire wheels on both sides. The following problems may occur during the processing:

[0003] 1) When the mortar is sprayed onto the steel wire, it will cause the steel wire to shake;

[0004] 2) The wire trough will wear out. As the usage time increases, the wear will become more and more serious, causing the steel wire to shake or deviate from its original motion trajectory.

[0005] The above problems will all lead to abnormal wafer thickness during the crystal rod cutting process. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a wire cutting device to solve the cutting anomaly caused by the cutting wire deviating from the motion trajectory.

[0007] In order to achieve the above-mentioned purpose, the technical solution adopted in the embodiment of the present invention is: a wire cutting device, comprising two wire wheels arranged opposite to each other, a cutting wire wound between the two wire wheels, a plurality of wire grooves arranged on the outer circumference of the wire wheels, and the cutting wire wound in the wire grooves.

[0008] The wire cutting device also includes at least one cutting wire limiting structure located between the two wire wheels, the cutting wire limiting structure includes limiting holes arranged in one-to-one correspondence with the plurality of wire grooves, the cutting wire passes through the limiting holes and is wound in the wire grooves of the wire wheels.

[0009] Optionally, the cutting line limiting structure includes:

[0010] A fixing rod, wherein the extending direction of the fixing rod is parallel to the axial direction of the guide wheel;

[0011] The limiting part includes a plurality of semi-enclosed annular parts with openings, the open ends of the semi-enclosed annular parts are fixedly connected to the fixing rod, and the semi-enclosed annular parts and the fixing rod are combined to form the limiting hole.

[0012] Optionally, the limiting hole is semicircular.

[0013] Optionally, the orthographic projection of the limiting hole on the corresponding wire pulley is located in the corresponding wire groove.

[0014] Optionally, the fixing rod is located at one side of the guide wheel in the radial direction, and the plurality of semi-enclosed annular members are arranged along the extending direction of the fixing rod.

[0015] Optionally, in the extension direction of the fixing rod, two adjacent semi-enclosed annular members at least partially overlap or do not overlap at all.

[0016] Optionally, at least one row of limiting units is included along the extending direction of the fixing rod, and the limiting units include a plurality of the semi-enclosed annular members arranged along the extending direction of the fixing rod.

[0017] Optionally, the wire wheel has two symmetrically arranged connecting shafts at opposite ends along its axial direction, the connecting line of the two connecting shafts coincides with the axial center line of the wire wheel, and the opposite ends of the fixing rod are respectively fixed on the corresponding connecting shafts.

[0018] Optionally, a nozzle for spraying mortar onto the cutting line is further included, and the cutting line limiting structure is located between the corresponding guide wheel and the nozzle.

[0019] Optionally, the nozzle comprises a strip-shaped injection port, and an extension direction of the strip-shaped injection port is parallel to an axial direction of the guide wheel.

[0020] The beneficial effect of the present invention is that the cutting line is limited in the corresponding wire groove by setting the cutting line limiting structure, thereby preventing the cutting line from deviating from the movement trajectory and causing cutting abnormalities. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram showing a wire cutting device in an embodiment of the present invention;

[0022] Figure 2 A schematic diagram showing a cutting line limiting structure in an embodiment of the present invention;

[0023] Figure 3 A schematic diagram showing a cutting line limiting structure in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0025] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate that there is at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0026] The features such as "parallel", "perpendicular", and "same" used in the embodiments of the present disclosure include the features such as "parallel", "perpendicular", and "same" in a strict sense, as well as the cases where "approximately parallel", "approximately perpendicular", "approximately the same", etc. include certain tolerances, taking into account the tolerances associated with the measurement of specific quantities (e.g., the limitations of the measurement system), and represent the acceptable deviation range for a specific value determined by ordinary technicians in the field. For example, "approximately" can mean within one or more standard deviations, or within 3% or 5% of the value.

[0027] As an important raw material in the semiconductor industry, silicon wafers are currently in short supply in the domestic market. Generally, silicon wafers are obtained by multi-wire cutting of crystal rods and grinding and polishing. During the wire cutting process, the processing table slowly descends, the crystal rod contacts the cutting wire for cutting, and the cutting wire reciprocates at a very high speed to cut the crystal rod. At present, wire cutting machines generally use a single pay-off shaft and a single take-up shaft. At the beginning, 400-1000 kilometers of cutting wire will be wound on the pay-off shaft, and there is no cutting wire on the take-up shaft. The specific reciprocating cutting process is: the pay-off shaft starts to pay out the wire, and the take-up shaft takes up the wire. The speed of the cutting wire gradually increases and advances a distance after reaching the set cutting speed, and then starts to decelerate to 0; then the take-up shaft starts to pay out the wire, and the pay-off shaft starts to take up the wire. The speed of the cutting wire gradually increases and advances a distance after reaching the set cutting speed, and then decelerates to 0; the above two processes are repeated until the crystal rod cutting is completed, wherein the forward distance of the pay-off shaft is greater than the forward distance of the take-up shaft, so the cutting wire on the pay-off shaft gradually decreases, and the cutting wire on the take-up shaft gradually increases until the cutting wire on the pay-off shaft is used up.

[0028] Mortar is an important material in the cutting process. In the online cutting equipment, the mortar is attached to the cutting line, and the cutting line drives the SiC particles in the mortar to grind and cut the crystal rod, and finally obtain silicon wafers with good thickness and flatness parameters (bending, warping, and overall thickness deviation). The crystal rod will generate a lot of heat during the cutting process, and the mortar is needed to take away the heat generated by grinding and cutting to prevent excessive heat during the cutting process from causing serious deformation of the silicon wafer.

[0029] However, during the cutting process, the mortar is sprayed onto the cutting line through the nozzle, which may cause the cutting line to vibrate.

[0030] The outer circumferences of the take-up shaft and the pay-off shaft are both provided with wire grooves for fixing the cutting wire. However, as the use time increases, the wire grooves will wear out, so that the cutting wire will shake or deviate from the motion trajectory.

[0031] In order to solve problems such as cutting line jitter and avoid cutting abnormalities that lead to abnormal thickness of the silicon wafer obtained by cutting, this embodiment provides a wire cutting device, which adds a cutting line limiting structure 3 to prevent the cutting line 2 from deviating from the motion trajectory and confine the cutting line 2 to the corresponding wire groove.

[0032] Specifically, refer to Figure 1-Figure 3 The wire cutting device provided in this embodiment includes two wire wheels 1 arranged opposite to each other, the two wire wheels 1 are arranged in parallel, one of the wire wheels 1 is a wire-releasing shaft, and the other wire wheel 1 is a wire-receiving shaft. A cutting wire 2 is wound between the two wire wheels 1, and a plurality of wire grooves are arranged on the outer circumferences of the two wire wheels 1 for fixing the cutting wire 2.

[0033] The wire cutting device also includes at least one cutting wire limiting structure 3 located between the two wire wheels 1, the cutting wire limiting structure 3 includes limiting holes 100 arranged in one-to-one correspondence with the plurality of wire grooves, the cutting wire 2 passes through the limiting holes 100 and is wound in the wire grooves of the wire wheels 1.

[0034] The cutting line limiting structure 3 is located between the two wire wheels 1, and the cutting line 2 includes a plurality of cutting line segments 2 located between the two wire wheels 1. One end of the cutting line segment 2 is wound around one wire wheel 1, and the other end of the cutting line segment 2 passes through the corresponding limiting hole 100 and is then wound around the other wire wheel 1. The plurality of limiting holes 100 are arranged in one-to-one correspondence with the plurality of wire grooves on each of the wire wheels 1. Through the arrangement of the cutting line limiting structure 3, the cutting line 2 is limited to always be located in the wire groove, thereby preventing the cutting line 2 from escaping from the corresponding wire groove and deviating from its preset motion trajectory.

[0035] In an exemplary embodiment, the wire cutting device further comprises a nozzle 4 for spraying mortar onto the cutting wire 2 , and the cutting wire limiting structure 3 is located between the corresponding wire wheel 1 and the nozzle 4 .

[0036] The nozzle 4 sprays mortar toward the cutting line 2, generating a certain force on the cutting line 2, causing the cutting line 2 to shake. In this embodiment, the cutting line limiting structure 3 is arranged between the nozzle 4 and the guide wheel 1, so that the impact force of the mortar on the cutting line 2 can be alleviated, thereby improving the shaking of the cutting line 2 caused by the mortar spraying.

[0037] In an exemplary embodiment, when the crystal ingot 10 is cut, the crystal ingot 10 is located between the two wire wheels 1, the axial direction of the crystal ingot 10 is parallel to the axial direction of the wire wheels 1, and one nozzle 4 is provided on both sides of the crystal ingot 10 in the radial direction. Figure 1 As shown, a cutting line limiting structure 3 can be set between each nozzle 4 and the corresponding wire wheel 1, that is, a cutting line limiting structure 3 is set between one nozzle 4 and the wire-releasing shaft, and a cutting line limiting structure 3 is set between one nozzle 4 and the wire-receiving shaft, so as to effectively prevent the cutting line 2 from shaking.

[0038] In an exemplary embodiment, the cutting line limiting structure 3 includes:

[0039] A fixing rod 31, wherein the extending direction of the fixing rod 31 is parallel to the axial direction of the guide wheel 1;

[0040] The limiting portion includes a plurality of semi-enclosed annular members 32 with openings. The open ends of the semi-enclosed annular members 32 are fixedly connected to the fixing rod 31 , and the semi-enclosed annular members 32 and the fixing rod 31 together form the limiting hole 100 .

[0041] The semi-enclosed annular member 32 and the fixing rod 31 together form the limiting hole 100, that is, the limiting hole 100 is a closed structure, and the cutting line 2 passing through the limiting hole 100 is always located in the limiting hole 100, and the plurality of limiting holes 100 and the plurality of wire grooves are arranged in a one-to-one correspondence, which effectively prevents the cutting line 2 from deviating from the motion trajectory and prevents the cutting line 2 from escaping from the corresponding wire groove.

[0042] In an exemplary embodiment, the cutting line limiting structure 3 includes:

[0043] A fixing rod 31, wherein the extending direction of the fixing rod 31 is parallel to the axial direction of the guide wheel 1;

[0044] The limiting portion includes a plurality of closed annular members, and the annular members are fixedly connected to the fixing rod 31 , that is, the annular members themselves form the limiting holes 100 .

[0045] In an exemplary embodiment, the limiting hole 100 is semicircular, but not limited thereto. For example, the limiting hole 100 may be semicircular or elliptical, and the portion of the limiting hole 100 facing the corresponding wire wheel 1 (the wire wheel 1 that is closer) is a convex surface that is protruded toward the corresponding wire wheel 1, so that the position of the cutting line 2 can be effectively adjusted. Even if the cutting line 2 is displaced, it will be restored to its original position due to the setting of the curved surface.

[0046] In an exemplary embodiment, the orthographic projection of the limiting hole 100 on the corresponding wire pulley 1 is located in the corresponding wire groove, that is, the length of the limiting hole 100 in the axial direction of the wire pulley 1 is less than or equal to the length of the wire groove in the axial direction of the wire pulley 1.

[0047] Preferably, the length of the limiting hole 100 in the axial direction of the wire wheel 1 is smaller than the length of the wire groove in the axial direction of the wire wheel 1 .

[0048] The above solution is adopted to ensure that the movement trajectory of the cutting line 2 remains unchanged, thereby preventing the cutting line 2 from escaping from the corresponding wire groove.

[0049] In an exemplary embodiment, the fixing rod 31 is located at one side of the guide wheel 1 in the radial direction, and the plurality of semi-enclosed annular members 32 are arranged along the extending direction of the fixing rod 31 .

[0050] The above solution makes it easier for the cutting wire 2 to pass through the limiting hole 100 and be wound around the two guide wheels 1 , thereby ensuring the movement trajectory of the cutting wire 2 .

[0051] In an exemplary embodiment, in the extension direction of the fixing rod 31, two adjacent semi-enclosed annular members 32 at least partially overlap or do not overlap at all. That is, along the circumferential direction of the fixing rod 31, two adjacent semi-enclosed annular members 32 may be staggered, or two adjacent semi-enclosed annular members 32 may be oppositely disposed, i.e., arranged in a row along the extension direction of the fixing rod 31.

[0052] In an exemplary embodiment, at least one row of limiting units is included along the extending direction of the fixing rod 31 , and the limiting units include a plurality of the semi-enclosed annular members 32 arranged along the extending direction of the fixing rod 31 .

[0053] When at least two rows of limiting units are included along the extending direction of the fixing rod 31 , the plate-enclosed annular members in two adjacent rows of limiting units may be staggered or may be opposite to each other.

[0054] In an exemplary embodiment, the semi-enclosed annular member 32 can be movably arranged on the fixed rod 31. For example, a plurality of annular tracks are arranged on the outer peripheral surface of the fixed rod 31 along the circumferential direction of the fixed rod 31, and the semi-enclosed annular member 32 can be movably arranged in the corresponding tracks. The tension of the cutting line 2 can be adjusted by moving the position of the semi-enclosed annular member 32.

[0055] In an exemplary embodiment, the semi-enclosed annular member 32 and the corresponding track can be fixedly connected by magnetic adsorption, or by other means. For example, a plurality of mounting holes are provided in the extension direction of the track, and the semi-enclosed annular member 32 is fixed in the corresponding track by screws engaging with the corresponding mounting holes. The method of screw fastening and mounting hole engagement not only realizes the adjustable position of the semi-enclosed annular member 32, but also improves the connection stability between the semi-enclosed annular member 32 and the fixing rod 31.

[0056] The cutting wire 2 passes through the limiting hole 100 and is wound around the guide wheel 1. During the cutting process, the guide wheel 1 is in a rotating state, while the cutting wire limiting structure 3 is fixed.

[0057] In an exemplary embodiment, the wire wheel 1 has two symmetrically arranged connecting shafts at opposite ends along its axial direction, and the connecting line of the two connecting shafts coincides with the axial center line of the wire wheel 1, and the opposite ends of the fixing rod 31 are respectively fixed on the corresponding connecting shafts.

[0058] Exemplarily, connecting rods 33 are respectively fixed at both ends of the fixing rod 31 in the extension direction, a screw hole 34 is provided at one end of the connecting rod 33 away from the fixing rod 31, and grooves are provided in the centers of the two end surfaces of the guide wheel 1, the grooves cooperate with the screw holes 34 for screws to pass through, so as to fix the cutting line limiting structure 3 on the guide wheel 1, and when the guide wheel 1 rotates, the cutting line limiting structure 3 is fixed.

[0059] By adopting the above solution, the relative position relationship between the cutting line limiting structure 3 and the guide wheel 1 is ensured, thereby ensuring the cutting quality.

[0060] In an exemplary embodiment, the nozzle 4 includes a strip-shaped injection port, and an extension direction of the strip-shaped injection port is parallel to the axial direction of the wire wheel 1 .

[0061] Exemplarily, the length of the strip-shaped injection port is greater than the axial length of the wire wheel 1 , ensuring that the nozzle 4 can spray mortar toward the cutting line 2 to cover all of the cutting line 2 .

[0062] In some embodiments, the cutting wire 2 is made of steel wire, and the material of the steel wire can be steel with a C content of 0.5-1.0%, steel with a Mn content of 0.05-0.1%, or steel with a Cr content of 0.01-0.1%, but it is not limited thereto.

[0063] In some implementations, the wire diameter of the cutting wire 2 is 0.05-0.2 mm.

[0064] In the axial direction of the wire wheel 1 , the inner diameter of the limiting hole 100 is larger than the wire diameter of the cutting wire 2 , so as to ensure that the cutting wire 2 can pass through the limiting hole 100 .

[0065] In an exemplary embodiment, the wire groove is a V-shaped structure, and the maximum width of the wire groove in the axial direction of the wire wheel 1 is greater than the wire diameter of the cutting wire 2 .

[0066] In an exemplary embodiment, the wire groove is an inverted trapezoidal structure, the area of ​​the bottom of the wire groove is smaller than the area of ​​the open end of the wire groove, and the length of the bottom of the wire groove in the axial direction of the wire wheel 1 is greater than the wire diameter of the cutting wire 2, preventing the cutting wire 2 from escaping from the wire groove.

[0067] In an exemplary embodiment, the bottom of the wire trough is a curved surface, so that the wire trough can move smoothly along the wire trough.

[0068] Generally, the cutting wire 2 wound on the spool will have a certain thickness. When the thickness exceeds a certain value, the external winding will affect the internal winding, because the external winding is used for cutting first. During the reciprocating cutting process, the mortar will be brought to the pay-off spool, causing pollution, thereby affecting the quality of the internal winding. To address this problem, in some implementations of this embodiment, the wire cutting device is provided with at least two groups of wire wheels 1 to reduce the thickness of the cutting wire 2 wound on each group of wire wheels 1, thereby improving the influence of the winding thickness of the cutting wire 2 on the cutting quality, preventing the external cutting wire 2 from escaping from the wire groove, reducing the degree of wear of the wire groove, and extending the service life of the wire wheel 1.

[0069] In some implementations of this embodiment, the wire cutting device includes at least two groups of wire wheels 1, and the wire diameters wound on at least the two groups of wire wheels 1 are different. For example, the wire cutting device includes a first group of wire wheels and a second group of wire wheels, and the wire diameter of the second cutting wire wound on the second group of wire wheels is different from the wire diameter of the first cutting wire on the first group of wire wheels (the structure of the second cutting wire is the same as the structure of the first cutting wire).

[0070] When cutting, the cutting process is divided into at least two cutting periods corresponding to the number of at least two groups of wire wheels 1, and cutting is performed in sequence using cutting wires 2 of different wire diameters in order from small to large. For example, at least two groups of wire wheels 1 include a first group of wire wheels and a second group of wire wheels, and the wire diameter of the first cutting wire wound on the first group of wire wheels is smaller than the wire diameter of the second cutting wire wound on the second group of wire wheels (the structure of the first cutting wire and the structure of the second cutting wire are the same). The cutting process is divided into two cutting periods. In the first cutting period (initial cutting period), the first cutting wire is used for cutting, and in the second cutting period, the second cutting wire is used for cutting. Since the mortar cutting ability decreases with the increase in the number of cutting times, the quality reduction caused by the decrease in the mortar cutting ability is compensated by increasing the wire diameter of the cutting wire 2 (the thicker the cutting wire 2, the stronger the ability to carry mortar, and the relatively stronger the cutting ability).

[0071] The wire diameters of the cutting wires 2 wound on different sets of wire wheels 1 can be set according to actual needs. For example, the wire diameter of the first cutting wire is 0.12-0.14 mm, and the wire diameter of the second cutting wire is 0.14-0.16 mm, but it is not limited thereto.

[0072] There are a few points to note:

[0073] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure, and other structures may refer to the general design.

[0074] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present disclosure, the thickness of layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0075] (3) In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to obtain new embodiments.

[0076] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A wire cutting device, comprising two wire wheels arranged opposite to each other, a cutting wire wound between the two wire wheels, a plurality of wire grooves arranged on the outer circumference of the wire wheels, the cutting wire wound in the wire grooves, characterized in that: The wire cutting device also includes at least one cutting wire limiting structure located between the two wire wheels, the cutting wire limiting structure includes limiting holes arranged in one-to-one correspondence with the plurality of wire grooves, the cutting wire passes through the limiting holes and is wound in the wire grooves of the wire wheels.

2. The wire cutting device according to claim 1, characterized in that: The cutting line limiting structure comprises: A fixing rod, wherein the extending direction of the fixing rod is parallel to the axial direction of the guide wheel; The limiting part includes a plurality of semi-enclosed annular parts with openings, the open ends of the semi-enclosed annular parts are fixedly connected to the fixing rod, and the semi-enclosed annular parts and the fixing rod are combined to form the limiting hole.

3. The wire cutting device according to claim 2, characterized in that: The limiting hole is semicircular.

4. The wire cutting device according to claim 2, characterized in that: The orthographic projection of the limiting hole on the corresponding wire pulley is located in the corresponding wire groove.

5. The wire cutting device according to claim 2, characterized in that: The fixing rod is located at one side of the guide wheel in the radial direction, and a plurality of the semi-enclosed annular members are arranged along the extending direction of the fixing rod.

6. The wire cutting device according to claim 5, characterized in that: In the extending direction of the fixing rod, two adjacent semi-enclosed annular members at least partially overlap or do not overlap at all.

7. The wire cutting device according to claim 5, characterized in that: At least one row of limiting units is included along the extending direction of the fixing rod, and the limiting units include a plurality of the semi-enclosed annular members arranged along the extending direction of the fixing rod.

8. The wire cutting device according to claim 2, characterized in that: The wire wheel has two symmetrically arranged connecting shafts at two opposite ends along its axial direction, and the connecting line of the two connecting shafts coincides with the axial center line of the wire wheel. The opposite ends of the fixing rod are respectively fixed on the corresponding connecting shafts.

9. The wire cutting device according to claim 5, characterized in that: It also includes a nozzle for spraying mortar onto the cutting line, and the cutting line limiting structure is located between the corresponding wire wheel and the nozzle.

10. The wire cutting device according to claim 9, characterized in that: The nozzle comprises a strip-shaped injection port, and an extension direction of the strip-shaped injection port is parallel to an axial direction of the guide wheel.

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