Coring method and system for workpiece

Abstract

The invention provides a coring method and system for a workpiece. The interior of the workpiece comprises a hardness increasing layer, the hardness of the hardness increasing layer is larger than that of the surface layer of the workpiece, and the coring method comprises the steps that a non-zero included angle is controlled to be formed between the axial direction of the coring tool and the thickness direction of the workpiece; and the coring tool is controlled to feed in the axial direction so as to carry out coring on the workpiece.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor manufacturing technology, and more particularly to a coring method and system for a workpiece. Background Art

[0002] In the field of semiconductor processing, coring technology is a precision processing technology that uses a cylindrical tool to perform circular cutting on the workpiece. Specifically, it separates the workpiece into a cylindrical center part and a hollow ring-shaped outer part through rotary cutting. It is widely used in aspects including material property detection (such as defect analysis) and structural processing (such as device cavity preparation).

[0003] In the semiconductor processing process, coring technology can significantly improve material utilization and reduce material waste by reasonably separating the center part of the workpiece from the outer part. Moreover, coring technology can accurately control the processing size and position, which is particularly suitable for occasions with high processing accuracy requirements, such as the processing of silicon wafers, silicon carbide wafers and sapphire wafers in semiconductor manufacturing.

[0004] However, despite the many advantages of coring technology, it still faces some technical challenges in actual operation. In particular, how to ensure that the coring tool does not get stuck during the coring process is a problem that needs to be solved urgently in this field. Summary of the invention

[0005] The present disclosure provides a coring method and system for a workpiece, which can solve the problem that the coring tool in the related art is prone to getting stuck during the coring process, and reduce the risk of deformation and damage of the coring tool and the workpiece during the coring process.

[0006] The technical solution of the present disclosure is achieved as follows: In a first aspect, the present disclosure provides a coring method for a workpiece, wherein the interior of the workpiece includes a hardness-enhanced layer, and the hardness of the hardness-enhanced layer is greater than the hardness of the surface layer of the workpiece, and the coring method comprises: Controlling a non-zero angle between the axial direction of the coring tool and the thickness direction of the workpiece; The coring tool is controlled to feed along the axial direction to coring the workpiece.

[0007] In some possible implementations, controlling the axial direction of the coring tool and the thickness direction of the workpiece to form a non-zero angle includes: The workpiece is controlled to be in an inclined state so that the axial direction and the thickness direction form the non-zero angle.

[0008] In some possible implementations, the coring method includes: disposing a tilting tool below the workpiece to make the workpiece tilted.

[0009] In some possible implementations, controlling the axial direction of the coring tool and the thickness direction of the workpiece to form a non-zero angle includes: The coring tool is controlled to be in an inclined state so that the non-zero angle is formed between the axial direction and the thickness direction.

[0010] In some possible implementations, the non-zero angle is obtained according to a first value determined based on a height corresponding to a portion with the highest hardness in the workpiece and a second value which is an outer diameter of the coring tool.

[0011] In some possible implementations, the height is obtained according to the maximum load of a spindle connected to the coring tool during coring.

[0012] In some possible implementations, the first value includes the height and a set coring safety distance.

[0013] In some possible implementations, the coring method is applied to a workpiece having a silicon carbide layer formed on both the upper surface and the lower surface of a graphite substrate.

[0014] In a second aspect, the present disclosure provides a coring system for a workpiece, wherein the interior of the workpiece includes a hardness-enhanced layer, the hardness of the hardness-enhanced layer is greater than the hardness of the surface layer of the workpiece, and the coring system includes: a coring tool, a first control unit and a second control unit, wherein: The first control unit is configured to control a non-zero angle between the axial direction of the coring tool and the thickness direction of the workpiece; The second control unit is configured to control the coring tool to feed along the axial direction to perform coring on the workpiece.

[0015] In some possible embodiments, the coring system further includes a tilting tool, which is disposed below the workpiece to tilt the workpiece so that the axial direction of the coring tool and the thickness direction of the workpiece form the non-zero angle.

[0016] The present disclosure provides a coring method and system for a workpiece; after controlling a non-zero angle between the axial direction of the coring tool and the thickness direction of the workpiece, the coring tool is controlled to feed in the axial direction to coring the workpiece, thereby avoiding the coring tool from getting stuck during the coring process, thereby improving the coring efficiency and avoiding the risk of deformation and damage to the coring tool and the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A three-dimensional schematic diagram of a coring tool provided in accordance with an embodiment of the present disclosure.

[0018] Figure 2 It is a three-dimensional schematic diagram of the workpiece after the coring operation is performed.

[0019] Figure 3 A schematic diagram of the structure of a workpiece provided for an embodiment of the present disclosure.

[0020] Figure 4 A schematic diagram of the change trend of the main shaft load during the coring process provided in the present invention.

[0021] Figure 5 A schematic flow chart of a coring method for a workpiece provided in the present invention.

[0022] Figure 6 Schematic diagram of the coring operation when the thickness direction of the workpiece is parallel to the axial direction of the coring tool.

[0023] Figure 7 A schematic diagram of a coring operation when a non-zero angle is formed between the thickness direction of a workpiece and the axial direction of a coring tool is provided for an embodiment of the present disclosure.

[0024] Figure 8 A schematic diagram of an implementation form of a workpiece in an inclined state provided in an embodiment of the present disclosure.

[0025] Fig. 9 A schematic diagram of a coring operation when a non-zero angle is formed between the thickness direction of a workpiece and the axial direction of a coring tool is provided for another embodiment of the present disclosure.

[0026] Fig.10 A schematic diagram of obtaining a non-zero angle between a thickness direction of a workpiece and an axial direction of a coring tool provided in the present disclosure.

[0027] Fig.11 A schematic structural diagram of a workpiece provided in accordance with another embodiment of the present disclosure.

[0028] Fig.12 A schematic diagram of the composition of a coring system for a workpiece provided in accordance with an embodiment of the present disclosure.

[0029] Fig.13 A schematic diagram of the composition of a coring system for a workpiece provided in accordance with another embodiment of the present disclosure. DETAILED DESCRIPTION

[0030] The technical solutions in the present disclosure will be described clearly and completely below in conjunction with the accompanying drawings in the present disclosure.

[0031] Unless otherwise defined, the technical terms used in the present disclosure should be understood as the common meanings known to those of ordinary skill in the art to which the present disclosure belongs. The terms "first", "second", etc. in the present disclosure do not indicate any order, but are only used to distinguish, and the terms "upper", "lower", etc. are only used to indicate relative positional relationships.

[0032] It should be noted that, for the sake of clarity, not all features of a specific implementation are described and illustrated in the specification and drawings. Furthermore, in order to avoid unnecessary details that obscure the technical solution focused on by the present disclosure, only the device structures and parts closely related to the technical solution of the present disclosure are described and illustrated in the specification and drawings, while other details that are not closely related to the technical content of the present disclosure and are known to those skilled in the art are omitted.

[0033] See also Figure 1 , which shows a scene in which the coring tool 1 provided by some embodiments of the present disclosure performs a coring operation on a workpiece 2. The coring tool 1 is cylindrical in shape as a whole, and may include a main body 11 and a cutting part 12 disposed on the main body 11.

[0034] In some examples, the main body 11 may be cylindrical. The cutting portion 12 may be substantially annular and concentrically disposed at one axial end 11A of the main body 11 relative to the central axis of the main body 11. In other words, the annular cutting portion 12 is concentrically disposed with the main body 11 and may extend from the axial end 11A of the main body 11 in the axial direction of the main body 11.

[0035] In the specific implementation process, the main body 11 can be connected to a rotation drive device (not shown in the figure), and the cutting part 12 can be formed as a whole with the main body 11, so that when the main body 11 is driven to rotate around its own axis, the cutting part 12 also rotates with the main body 11 around the central axis common with the main body 11. The cutting part 12 is provided with a cutting blade at its free end surface, which is used to apply a cutting force to the workpiece 2 during the rotation process, thereby gradually cutting the material and forming a cylindrical cutting path. The cutting blade can be continuous or can be distributed with teeth at a certain interval to better remove chips and reduce friction generated during the cutting process. This disclosure does not make specific limitations.

[0036] The workpiece 2 can be separated into two parts by the coring tool 1. Figure 2 As shown, a cylindrical first component 2A is taken out from the center of the workpiece 2, and the remaining portion is a hollow ring-shaped second component 2B.

[0037] However, the above-mentioned coring tool 1 still has some problems in actual cutting operation. Specifically, when the interior of the workpiece 2 includes a hardness-enhanced layer, and the hardness of the hardness-enhanced layer is greater than the hardness of the surface layer of the workpiece 2, as the hardness of the workpiece 2 increases, the cutting force required by the coring tool 1 will also increase. Figure 3 Taking the graphite substrate 21 and the SiC layer 22 formed on the surface of the graphite substrate 21 by vapor deposition as an example, during the vapor deposition process, the (111) crystal plane of the SiC layer 22 close to the graphite substrate 21 has a higher proportion of grains, so its hardness is also higher; while the (111) crystal plane of the SiC layer 22 far from the graphite substrate 21 has a lower proportion of grains, so its hardness is also lower. Based on this, the hardness of the SiC layer 22 in the surface layer of the workpiece 2 is lower than the hardness of the SiC layer 22 in other areas.

[0038] It should be noted that Figure 3 The hardness variation trend of different SiC layers 22 is reflected by the density of the filling pattern.

[0039] During the coring process, since the hardness of the SiC layer 22 increases as it is closer to the graphite substrate 21, the cutting force required by the coring tool 1 increases as it is closer to the graphite substrate 21. When performing the coring operation, the coring tool 1 is mounted on a spindle (not shown in the figure) of a processing device, and the load of the spindle is converted into the cutting force required by the coring tool 1. Therefore, when the cutting force required by the coring tool 1 increases, the load on the spindle will also increase accordingly. Figure 4 As shown in FIG. 1 , it shows a schematic diagram of the change trend of the spindle load during the coring process. During the coring process, when the spindle load exceeds Figure 4 When the dotted line A in the figure indicates that the feed rate of the coring tool 1 needs to be reduced; when the spindle load exceeds Figure 4 When the dotted line B in the figure is reached, it means that the load of the spindle has exceeded its maximum load. At this time, it is necessary to stop the coring operation on the workpiece 2 to avoid damage to the coring tool 1 and the processing equipment. It can be seen that once the load of the spindle exceeds its set load range, the coring tool 1 cannot continue to feed, resulting in a jam. Even if the feed rate of the coring tool 1 is reduced or its rotation speed is adjusted for multiple times, the coring tool 1 still cannot continue to cut the workpiece 2.

[0040] In view of the above problems, the embodiment of the present disclosure proposes a coring method, through which the coring method can ensure that the coring tool 1 completes the coring operation on the workpiece 2 during the coring process without getting stuck, thereby improving the efficiency of the coring operation and reducing the risk of deformation and damage of the coring tool 1 and the workpiece 2. Specifically, see Figure 5 , which shows a coring method for a workpiece 2 provided by the present disclosure, and the coring method specifically includes the following steps.

[0041] In step S501 , a non-zero angle is formed between the axial direction of the coring tool 1 and the thickness direction of the workpiece 2 .

[0042] by Figure 3 Taking the workpiece 2 shown in FIG. 1 as an example, its SiC layer 22 is formed by stacking materials layer by layer on a graphite substrate 21 through a vapor deposition process. Figure 3 In the workpiece 2 shown, along the thickness direction of the workpiece 2, the hardness of each region of each SiC layer 22 is uniform.

[0043] like Figure 6 As shown, when the axial direction of the coring tool 1 is parallel to the thickness direction of the workpiece 2, during the coring process, since the hardness of each region of each SiC layer 22 is the same, the cutting resistance of these regions to the coring tool 1 is the same, and the cutting resistance is concentrated on a single SiC layer 22. When the coring tool 1 is fed to the SiC layer 22 with the greatest hardness close to the graphite substrate 21, the load of the spindle reaches the maximum load. At this time, since the spindle cannot overcome the cutting resistance of the coring tool 1 by increasing the load to provide a greater cutting force to the coring tool 1, the coring tool 1 will get stuck when cutting the SiC layer 22 with the greatest hardness, causing the cutting process to stop.

[0044] In the present disclosure, a non-zero angle is formed between the axial direction of the coring tool 1 and the thickness direction of the workpiece 2. , such as Figure 7 As shown, the problem that the coring tool 1 is prone to get stuck during the coring process can be effectively solved. This is because when the axial direction of the coring tool 1 and the thickness direction of the workpiece 2 form a non-zero angle , the coring tool 1 is no longer perpendicular to the thickness direction of the workpiece 2 during feeding, but cuts into the workpiece 2 obliquely. Since the hardness of each area at the same horizontal height of the workpiece 2 is different, the coring tool 1 can start cutting from the area with smaller hardness, thereby cutting the workpiece 2. In addition, this oblique cutting method makes the cutting resistance encountered by the coring tool 1 during the cutting process no longer concentrated on a single layer of SiC layer 22, but dispersed in SiC layers 22 with different hardness. This uneven hardness distribution leads to the dispersion of cutting resistance, which significantly reduces the maximum cutting force required by the coring tool 1. Correspondingly, the load on the spindle is also reduced. Therefore, the coring tool 1 can continue to feed under a lower load, thereby effectively avoiding the jamming phenomenon caused by excessive cutting resistance and improving the stability and reliability of the coring process.

[0045] Furthermore, by controlling the axial direction of the coring tool 1 and the thickness direction of the workpiece 2 to form a non-zero angle , the width of the groove cut by the cutting edge of the coring tool 1 on the workpiece 2 can be made greater than the thickness of the cutting edge itself. In this case, a certain gap is formed between the outer peripheral side of the coring tool 1 and the workpiece 2, which is conducive to the discharge of debris.

[0046] In step S502 , the coring tool 1 is controlled to feed in the axial direction to coring the workpiece 2 .

[0047] In the present disclosure, when the axial direction of the coring tool 1 and the thickness direction of the workpiece 2 form a non-zero angle , the coring tool 1 is still limited to feed along its axial direction. This is because the structure of the coring tool 1 and the geometric shape of the cutting edge are designed based on the axial direction of the coring tool 1. If the feeding direction of the coring tool 1 is changed, the cutting performance of the coring tool 1 may be reduced or even damaged. In addition, controlling the feeding of the coring tool 1 along the axial direction can better control the direction and magnitude of the cutting force. This control method can ensure that the cutting force is evenly distributed on the cutting edge, avoid local stress concentration caused by changes in the direction of the cutting force, and thus ensure the final cutting quality and cutting accuracy of the workpiece 2.

[0048] For the technical solution provided by the present disclosure, by controlling the axial direction of the coring tool 1 and the thickness direction of the workpiece 2 to form a non-zero angle Afterwards, the coring tool is controlled to feed along the axial direction to coring the workpiece, which can avoid the coring tool 1 from getting stuck during the coring process, thereby improving the coring efficiency and avoiding the risk of deformation and damage of the coring tool 1 and the workpiece 2.

[0049] In the specific implementation process, the axial direction of the coring tool 1 and the thickness direction of the workpiece 2 are controlled to form a non-zero angle. In some possible implementations, the above-mentioned control of the axial direction of the coring tool 1 and the thickness direction of the workpiece 2 to form a non-zero angle includes: The workpiece 2 is controlled to be in an inclined state so that the axial direction and the thickness direction form the non-zero angle.

[0050] like Figure 7 As shown, in order to make the axial direction of the coring tool 1 and the thickness direction of the workpiece 2 form a non-zero angle In the specific implementation process, the workpiece 2 can be controlled to be in an inclined state. More specifically, as Figure 8 As shown, a tilting tool 3 can be arranged below the workpiece 2 so that the workpiece 2 is tilted.

[0051] The setting of the tilting tool 3 can be optimized according to actual needs. In some examples, the tilting tool 3 can specifically include a tilting workbench and a mounting seat for carrying the workpiece 2, and the tilting workbench and the mounting seat can be rotatably arranged. In the specific implementation process, the tilting angle of the workpiece 2 can be accurately controlled by the angle measurement module. In addition, by replacing the angle measurement blocks of different angles, the tilting angle of the workpiece 2 can be quickly adjusted to meet different coring requirements. In other examples, the tilting tool 3 can achieve precise angle adjustment through a driving mechanism (such as a screw and a cylinder). For example, the tilting tool 3 is driven by a screw to rotate until the desired angle is obtained and then fixed to achieve a stable tilting state. In the present disclosure, the tilting tool 3 can not only effectively achieve the tilting of the workpiece 2, but also improve the flexibility and efficiency of the processing process, while ensuring the processing accuracy and stability.

[0052] Of course, in addition to this, Figure 5 In some possible implementations of the technical solution shown, Fig. 9 As shown, the above-mentioned control of the axial direction of the coring tool 1 and the thickness direction of the workpiece 2 to form a non-zero angle includes: The coring tool 1 is controlled to be in an inclined state so that the axial direction and the thickness direction form the non-zero angle.

[0053] In some examples, in order to make the coring tool 1 in an inclined state, it can be achieved by adjusting the main axis or using the axis coupling function of the inclined axis. This disclosure does not make any specific limitation to this.

[0054] It should be noted that in the present disclosure, the non-zero angle between the axial direction of the coring tool 1 and the thickness direction of the workpiece 2 is achieved. The specific implementation is not limited to the above-mentioned control of the workpiece 2 to be in an inclined state or the control of the coring tool 1 to be in an inclined state. In the specific implementation process, the non-zero angle between the above-mentioned axial direction and the above-mentioned thickness direction can also be achieved by simultaneously controlling the workpiece 2 and the coring tool 1 to be in an inclined state. The present disclosure does not impose further limitations on the specific implementation manner.

[0055] for Figure 5 In some possible implementations of the technical solution shown, the non-zero angle According to the height corresponding to the part with the highest hardness in the workpiece 2 The first value determined is the outer diameter of the coring tool 1 The second value is obtained.

[0056] In the present disclosure, the outer diameter of the coring tool 1 is It refers to the maximum outer circumferential diameter of the cutting portion 12 of the coring tool 1, that is, the diameter of the circular track formed by the coring tool 1 when it rotates and cuts.

[0057] In some examples, such as Fig.10 As shown, the non-zero angle According to the first value and the outer diameter of the coring tool 1 The second value is obtained, and the specific calculation formula is as follows: .

[0058] Since the first value Greater than the height corresponding to the hardest part of workpiece 2 , so we can get: .

[0059] It can be understood that during the coring process, if the angle between the axial direction of the coring tool 1 and the thickness direction of the workpiece 2 is If the diameter is too large, the inner diameter of the hollow annular second component 2B obtained after coring will be inaccurate, and the concentricity of the inner circle and the outer circle will deteriorate. In addition, in order to ensure that the quality of the product obtained by coring is within a controllable range and to reduce the load on the spindle, the first value is determined in the specific implementation process. It is also necessary to consider the coring safety distance to avoid direct contact between the coring tool 1 and the part with greater hardness and to prevent the spindle from being overloaded. For the above height And the set coring safety distance , then the above calculation formula can be expressed as follows: .

[0060] In the present disclosure, the coring safety distance It can be determined according to the actual situation, such as the core sampling safety distance The thickness may be 0.1 mm, which is not specifically limited in the present disclosure.

[0061] Optionally, in some examples, the height It is obtained according to the maximum load of the main shaft connected to the coring tool 1 during coring.

[0062] During the coring process, the maximum load data of the spindle can be recorded in real time, such as Figure 4As shown. These load data can usually be obtained by sensors installed on the spindle. At the same time, the depth information of coring is recorded, that is, the position of the coring tool 1 at different depths. Subsequently, the maximum load data of the spindle is associated with the depth information of coring. Generally, an increase in the load of the spindle indicates that the coring tool 1 has been fed to a part with greater hardness. By analyzing the load variation curve with depth, the depth points where the load suddenly increases can be identified, and these depth points usually correspond to parts with greater hardness in the workpiece 2. When the depth point when the load reaches the maximum value is obtained, the location of the hardest part of the workpiece 2 can be determined. If the load reaches a high value at multiple depth points, the hardest part can be determined by further analyzing the load variation trend. For example, the hardest part may correspond to an area with the highest load peak or a continuously increasing load. Through the above steps, the maximum load data of the spindle during coring can be used to determine the height corresponding to the hardest part of the workpiece 2.

[0063] for Figure 5 In some possible implementations of the technical solution shown, Fig.11 As shown, the coring method is applied to a workpiece 2 having a silicon carbide layer 22 formed on both the upper and lower surfaces of a graphite substrate 21 .

[0064] See also Fig.12 The present disclosure further provides a coring system 120 for a workpiece 2, wherein the interior of the workpiece 2 includes a hardness-enhanced layer, and the hardness of the hardness-enhanced layer is greater than the hardness of the surface layer of the workpiece 2. The coring system 120 includes: a coring tool 1, a first control unit 1201 and a second control unit 1202, wherein: The first control unit 1201 is configured to control a non-zero angle between the axial direction of the coring tool 1 and the thickness direction of the workpiece 2; The second control unit 1202 is configured to control the coring tool 1 to feed along the axial direction to perform coring on the workpiece 2 .

[0065] It should be noted that for the specific implementation methods or implementation examples of the functions configured by the above-mentioned components, please refer to the corresponding implementation methods and examples of the aforementioned technical solutions, and this disclosure will not elaborate on them here.

[0066] In some examples, such as Fig.13 As shown, the coring system 120 further includes a tilting tool 3, which is disposed below the workpiece 2 to tilt the workpiece 2 so that the axial direction of the coring tool 1 and the thickness direction of the workpiece 2 form the non-zero angle.

[0067] It should be noted that the technical solutions described in the present disclosure can be combined arbitrarily without conflict.

[0068] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A coring method for a workpiece, wherein the interior of the workpiece includes a hardness-enhanced layer, the hardness of the hardness-enhanced layer is greater than the hardness of the surface layer of the workpiece, characterized in that: The coring method comprises: Controlling a non-zero angle between the axial direction of the coring tool and the thickness direction of the workpiece; The coring tool is controlled to feed along the axial direction to coring the workpiece.

2. The coring method for a workpiece according to claim 1, characterized in that: The step of controlling the axial direction of the coring tool and the thickness direction of the workpiece to form a non-zero angle comprises: The workpiece is controlled to be in an inclined state so that the axial direction and the thickness direction form the non-zero angle.

3. The coring method for a workpiece according to claim 2, characterized in that: The coring method comprises: arranging an inclined tool below the workpiece to make the workpiece in an inclined state.

4. The coring method for a workpiece according to claim 1, characterized in that: The step of controlling the axial direction of the coring tool and the thickness direction of the workpiece to form a non-zero angle comprises: The coring tool is controlled to be in an inclined state so that the non-zero angle is formed between the axial direction and the thickness direction.

5. The coring method for a workpiece according to claim 1, characterized in that: The non-zero angle is obtained according to a first value determined based on a height corresponding to a portion with the greatest hardness in the workpiece and a second value which is an outer diameter of the coring tool.

6. The coring method for a workpiece according to claim 5, characterized in that: The height is obtained according to the maximum load of the main shaft connected to the coring tool during coring.

7. The coring method for a workpiece according to claim 5, characterized in that: The first value includes the height and a set coring safety distance.

8. A coring method for a workpiece according to any one of claims 1 to 7, characterized in that: The coring method is applied to a workpiece having silicon carbide layers formed on both the upper and lower surfaces of a graphite substrate.

9. A coring system for a workpiece, wherein the interior of the workpiece includes a hardness-enhanced layer, the hardness of the hardness-enhanced layer is greater than the hardness of the surface layer of the workpiece, characterized in that: The coring system comprises: a coring tool, a first control unit and a second control unit, wherein: The first control unit is configured to control a non-zero angle between the axial direction of the coring tool and the thickness direction of the workpiece; The second control unit is configured to control the coring tool to feed along the axial direction to perform coring on the workpiece.

10. The coring system for a workpiece according to claim 9, characterized in that: The coring system further comprises a tilting tool, which is arranged below the workpiece to tilt the workpiece so that the workpiece is in an inclined state, thereby forming the non-zero angle between the axial direction of the coring tool and the thickness direction of the workpiece.

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