Crystal ingot processing method and crystal ingot processing apparatus
By detecting ingot defects and performing inclined cylindrical grinding, the problem of ineffective removal of inclined defects in ingots in existing technologies has been solved, thereby improving the effective thickness of ingots and the processing yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING TIANKE HEDA SEMICON CO LTD
- Filing Date
- 2025-03-05
- Publication Date
- 2026-05-12
AI Technical Summary
Existing cylindrical grinding machines cannot effectively remove defects that grow obliquely on ingots, resulting in a reduction in the effective thickness of the ingot or damage during processing, which affects the processing yield and output.
By detecting defects on the ingot, the maximum depths h1 and h2 are determined, and the minimum removal amount m is determined based on these depths. The inclined cylindrical grinding machine is used to remove the inclined defects on the sidewall of the ingot, resulting in an inclined cylindrical ingot.
It effectively removes oblique defects on crystal ingots, increases the effective thickness of processed crystal ingots, reduces breakage rate, and improves processing yield and material utilization.
Smart Images
Figure CN119871106B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor processing technology, and in particular to ingot processing methods and ingot processing equipment. Background Technology
[0002] The growth of silicon carbide crystals is challenging, as factors such as temperature, pressure, and growth rate all affect their quality. Currently, silicon carbide crystal growth primarily employs physical vapor transport (PVT), high-temperature chemical vapor deposition (HTCVD), and liquid phase methods. PVT, after years of development, has become a relatively mature process, making it more suitable for industrial-scale mass production. The principle behind PVT is as follows: carbon and silicon powders are placed at the bottom of a crucible, while a silicon carbide seed crystal is placed at the top. Under high temperature and low pressure conditions in a sealed environment, the sublimated powders are transported upwards to the vicinity of the seed crystal through temperature gradients and concentration differences. Once supersaturated, the powder recrystallizes, thus achieving silicon carbide crystal growth.
[0003] The surface and sidewalls of silicon carbide ingots grown using the PVT method are irregular. The circumference of the ingots often contains defects such as edge cracks and impurities. Generally, the original silicon carbide ingot needs to be machined into a silicon carbide ingot of a certain size through planar machining and rough external cylindrical machining. Then, the ingot is machined into a standard-sized cylindrical crystal using an external cylindrical grinding machine. However, growth defects such as cracks and impurities may move closer to the central axis of the silicon carbide ingot during the growth process. Most external cylindrical grinding machines can only uniformly remove the sidewalls of the ingot. Thus, some obliquely grown defects or areas that need to be removed cannot be completely removed, resulting in a reduced effective thickness due to thickness defects, or even breakage during processing, affecting the processing yield and output of the silicon carbide ingot. Of course, this problem is not limited to silicon carbide ingots; ingots of other materials also face similar issues if they have obliquely grown defects or areas that need to be removed. Summary of the Invention
[0004] To address the aforementioned technical problems, this application provides a crystal ingot processing method and equipment to effectively remove obliquely grown defects or obliquely removed areas from the crystal ingot, thereby increasing the effective thickness of the processed crystal ingot, reducing the crystal ingot breakage rate, and improving the crystal ingot processing yield and output.
[0005] To achieve the above objectives, the embodiments of this application provide the following technical solutions:
[0006] In a first aspect, embodiments of this application provide a method for processing crystal ingots, the method comprising:
[0007] Obtain a crystal ingot to be processed, the crystal ingot to be processed is cylindrical, the diameter of the bottom surface of the crystal ingot to be processed is D1, and the thickness of the crystal ingot to be processed is z1;
[0008] Detect defects on the ingot to be processed, determine the maximum depth h1 of the defect that penetrates from the sidewall to the central axis on the ingot to be processed, and determine the depth h2 of the defect that penetrates from the sidewall to the central axis in the region opposite to the maximum depth h1 in the bottom surface along the radial direction of the bottom surface, where 0≤h2
[0009] The maximum depth h1 is defined as the location of the maximum removal amount on the bottom surface where the maximum depth h1 is located. Based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, the minimum removal amount m on the bottom surface where the maximum depth h1 is located is determined, where D1-D2≥h1+m, and the location of the minimum removal amount is opposite to the location of the maximum removal amount along the radial direction of the bottom surface where the maximum depth h1 is located.
[0010] The ingot to be processed is processed by an external cylindrical grinding machine using a grinding wheel, wherein the grinding wheel is cylindrical, the sidewall of the ingot to be processed is placed opposite the sidewall of the grinding wheel, the bottom surface of the ingot to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel, tanα=(h1-m) / z1, and the maximum depth h1 is the tip position of the ingot to be processed, thereby obtaining a slanted cylindrical ingot, the bottom surface of the slanted cylindrical ingot is circular, and the sidewall of the slanted cylindrical ingot is inclined at an angle α relative to the high surface.
[0011] Optionally, determining the minimum removal amount m of the bottom surface where the maximum depth h1 is located, based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, includes:
[0012] Compare the size of h2 with (D1-D2-h1);
[0013] If h2≤(D1-D2-h1), then determine the minimum removal amount m=h2 at the bottom surface where the maximum depth h1 is located;
[0014] If h2 > (D1 - D2 - h1), then determine the minimum removal amount m = (D1 - D2 - h1) of the bottom surface where the maximum depth h1 is located.
[0015] Optionally, the external cylindrical grinding of the ingot to be processed by a grinding wheel includes:
[0016] The clamping member holds the ingot to be processed by an auxiliary block. The auxiliary block includes a bottom surface and an inclined surface at an angle α relative to its bottom surface. The inclined surface of the auxiliary block is in contact with the bottom surface of the ingot to be processed. The bottom surface of the auxiliary block is in contact with the clamping member. The line connecting the highest and lowest points of the inclined surface of the auxiliary block and its bottom surface is parallel to the radial direction of the bottom surface of the ingot to be processed where the maximum depth h1 is located. The center of the inclined surface and bottom surface of the auxiliary block, the center of the bottom surface of the ingot to be processed, and the central axis of the clamping member are aligned, so that the side wall of the ingot to be processed is placed opposite the side wall of the grinding wheel. The bottom surface of the ingot to be processed is at an angle α relative to the bottom surface of the grinding wheel, and the maximum depth h1 is the tip position of the ingot to be processed.
[0017] By moving the grinding wheel and moving and rotating the ingot to be processed, the sidewall of the grinding wheel is obliquely removed from the sidewall of the ingot to be processed, resulting in an oblique cylindrical ingot with a circular bottom surface and the sidewall of the oblique cylindrical ingot at a high tilt angle α.
[0018] Optionally, before grinding the ingot with a grinding wheel using an external cylindrical grinding machine, the ingot processing method further includes:
[0019] The auxiliary block is selected such that the elliptical inclined surface of the selected auxiliary block is inclined at an angle α relative to its circular base, and the distance r between the inclined surface of the selected auxiliary block and the highest and lowest points of its base is less than D2.
[0020] When the clamping component holds the ingot to be processed through the auxiliary block, the circular bottom surface of the auxiliary block is parallel to the bottom surface of the grinding wheel.
[0021] Optionally, the ingot processing method further includes:
[0022] The oblique cylindrical ingot is cut using a parallel line mesh, wherein the extension direction of the parallel lines in the parallel line mesh is parallel to the bottom surface of the oblique cylindrical ingot, and the arrangement direction of the parallel lines in the parallel line mesh is perpendicular to the bottom surface of the oblique cylindrical ingot, thereby obtaining multiple oblique cylindrical wafers.
[0023] Optionally, the ingot processing method further includes:
[0024] The oblique cylindrical wafer is chamfered to obtain a standard cylindrical wafer, wherein the thickness of the oblique cylindrical wafer is x, the diameter of the bottom surface of the oblique cylindrical wafer is D2, the skewness of the sidewall of the oblique cylindrical wafer is y=xtanα, the diameter of the bottom surface of the standard cylindrical wafer is D3, and (D2-D3)≥y.
[0025] Optionally, the ingot processing method is applied to silicon carbide ingots.
[0026] Secondly, embodiments of this application provide an ingot processing apparatus, the ingot processing apparatus comprising:
[0027] A crystal ingot acquisition device is used to perform rough processing on the grown crystal embryo to obtain a crystal ingot to be processed. The crystal ingot to be processed is cylindrical, the diameter of the bottom surface of the crystal ingot to be processed is D1, and the thickness of the crystal ingot to be processed is z1.
[0028] A defect detection device is used to detect defects on the ingot to be processed, determine the maximum depth h1 of the defect that penetrates from the sidewall to the central axis on the ingot to be processed, and determine the depth h2 of the defect from the sidewall to the central axis in the region opposite to the maximum depth h1 in the bottom surface along the radial direction of the bottom surface, where 0≤h2
[0029] The computing device defines the maximum depth h1 as the location of the maximum removal amount on the bottom surface where the maximum depth h1 is located, and determines the minimum removal amount m on the bottom surface where the maximum depth h1 is located based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, where D1-D2≥h1+m, and the location of the minimum removal amount is opposite to the location of the maximum removal amount along the radial direction of the bottom surface.
[0030] An external cylindrical grinding machine processing device performs external cylindrical grinding on a crystal ingot to be processed using a grinding wheel. The grinding wheel is cylindrical, and the sidewall of the crystal ingot to be processed is placed opposite the sidewall of the grinding wheel. The bottom surface of the crystal ingot to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel, where tanα=(h1-m) / z1. The maximum depth h1 is the tip position of the crystal ingot to be processed, thereby obtaining a slanted cylindrical crystal ingot. The bottom surface of the slanted cylindrical crystal ingot is circular, and the sidewall of the slanted cylindrical crystal ingot is inclined at an angle α relative to the high surface.
[0031] Optionally, the ingot processing equipment further includes:
[0032] A multi-wire cutting device uses a parallel wire mesh to cut the oblique cylindrical crystal ingot. The extension direction of the parallel wire mesh is parallel to the bottom surface of the oblique cylindrical crystal ingot, and the arrangement direction of the parallel wire mesh is perpendicular to the bottom surface of the oblique cylindrical crystal ingot, thereby obtaining multiple oblique cylindrical wafers.
[0033] Optionally, the ingot processing equipment further includes:
[0034] A chamfering processing device performs chamfering processing on the oblique cylindrical wafer to obtain a standard cylindrical wafer, wherein the thickness of the oblique cylindrical wafer is x, the diameter of the bottom surface of the oblique cylindrical wafer is D2, the skewness of the sidewall of the oblique cylindrical wafer is y=xtanα, the diameter of the bottom surface of the standard cylindrical wafer is D3, and (D2-D3)≥y.
[0035] Compared with existing technologies, the above technical solution has the following advantages:
[0036] Compared to existing cylindrical grinding machines that can only uniformly remove the sidewalls of ingots, the ingot processing method provided in this application, after obtaining an ingot with a bottom diameter of D1 and a thickness of z1, first detects defects on the ingot, determines the maximum depth h1 of the deepest defect extending from the sidewall to the central axis, and determines the depth h2 of the defect extending from the sidewall to the central axis in the region opposite to the maximum depth h1 on the bottom surface, along the radial direction of the bottom surface, where 0 ≤ h2 < h1; then, the maximum depth h1 is defined as the location of the maximum removal amount on the bottom surface where the maximum depth h1 is located, and based on h2 and the target diameter D2 of the bottom surface of the ingot, determines the minimum removal amount m on the bottom surface where the maximum depth h1 is located, where D1 - D2 ≥ h1 + m, and the location of the minimum removal amount and the location of the maximum removal amount are along the maximum depth h. The radial directions of the bottom surfaces are opposite; thus, when the ingot to be processed is machined by a cylindrical grinding wheel, the sidewall of the ingot to be processed is placed opposite the sidewall of the grinding wheel, and the bottom surface of the ingot to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel, tanα=(h1-m) / z1, and the maximum depth h1 is the tip position of the ingot to be processed, thereby realizing the oblique removal of the sidewall of the ingot, removing defects on the ingot to a greater extent, especially the defects that penetrate the deepest from the sidewall to the central axis, resulting in an oblique cylindrical ingot. The bottom surface of the oblique cylindrical ingot is circular, and the sidewall of the oblique cylindrical ingot is inclined at a high angle α, thereby effectively removing obliquely grown defects or obliquely removed areas on the ingot, increasing the effective thickness of the ingot after processing, reducing the ingot processing breakage rate, improving the processing yield and output of the ingot, and also helping to improve the utilization rate of the ingot material. Attached Figure Description
[0037] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0038] Figure 1 This is a side view of a crystal ingot 10 to be processed;
[0039] Figure 2 A schematic diagram of a machining process using an existing cylindrical grinding machine;
[0040] Figure 3 This is a schematic diagram showing another perspective of machining on an existing cylindrical grinding machine.
[0041] Figure 4 A side view schematic diagram of the uniform removal of the sidewall of the ingot 10 to be processed using an existing cylindrical grinding machine;
[0042] Figure 5 This is a schematic diagram of a perspective view of the ingot processing method provided in the embodiments of this application, which involves oblique external cylindrical grinding of the ingot 10 to be processed.
[0043] Figure 6 This is a schematic diagram from another perspective of the ingot processing method provided in the embodiments of this application, which performs oblique external cylindrical grinding on the ingot 10 to be processed.
[0044] Figure 7 This is a side view schematic diagram of the oblique removal of the sidewall of the ingot 10 to be processed using the ingot processing method provided in the embodiments of this application;
[0045] Figure 8 This is a schematic diagram of the bottom surface of the ingot 10 to be processed, showing the oblique removal of the sidewalls using the ingot processing method provided in the embodiments of this application;
[0046] Figure 9 A schematic diagram of one perspective of auxiliary block 40;
[0047] Figure 10 This is a schematic diagram of auxiliary block 40 from another perspective;
[0048] Figure 11 This is a schematic diagram of parallel wire mesh cutting of a slanted cylindrical ingot 11 using the ingot processing method provided in the embodiments of this application;
[0049] Figure 12 A schematic diagram showing how to first attach a standard cylindrical ingot obtained after processing by an existing cylindrical grinding machine to a resin plate 60, and then attach the resin plate 60 to the worktable fixture 70 of a multi-wire cutting machine.
[0050] Figure 13 This is a schematic diagram illustrating the use of a parallel wire mesh 50 of a multi-wire cutting machine to cut a standard cylindrical ingot in the prior art;
[0051] Figure 14 This is a schematic diagram illustrating the cutting of a standard cylindrical ingot processed by an existing cylindrical grinding machine using a parallel grid 50 in the prior art.
[0052] Figure 15 A side view of the oblique cylindrical wafer 12 obtained by parallel wire mesh cutting of the oblique cylindrical ingot 11 using the ingot processing method provided in the embodiments of this application;
[0053] Figure 16 This is a schematic diagram of a crystal ingot processing equipment provided in an embodiment of this application. Detailed Implementation
[0054] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0055] As described in the background section, when silicon carbide ingots or other material ingots have defects that grow obliquely or areas that need to be removed obliquely, existing cylindrical grinding machines can only uniformly remove the sidewalls of the ingot. Therefore, some of the obliquely grown defects or areas that need to be removed obliquely cannot be completely removed, resulting in a reduction in the effective thickness of the ingot due to defects in some thicknesses, or processing damage, affecting the processing yield and output of the ingot.
[0056] Figure 1 A side view schematic diagram of a crystal ingot 10 to be processed is shown, as follows: Figure 1 As shown, the ingot 10 to be processed is cylindrical, and includes two opposing bottom surfaces and sidewalls connecting the two opposing bottom surfaces. Taking the ingot 10 to be processed as a silicon carbide ingot as an example, after obtaining the silicon carbide embryo using the PVT method, the original silicon carbide embryo is first processed into a silicon carbide ingot of a certain size through planar machining and outer diameter rough machining. Figure 1 As shown in the cylindrical ingot, it can be seen that the ingot 10 to be processed has edge defects that move closer to the central axis of the ingot as it grows.
[0057] Figure 2 This diagram illustrates a perspective view of machining on an existing cylindrical grinding machine. Figure 3 This diagram illustrates another perspective of machining on existing cylindrical grinding machines, combined with... Figure 2 and Figure 3 As shown, when the ingot 10 is processed using a conventional cylindrical grinding machine, the ingot 10 is held in place by the clamping member 20 from both bottom surfaces, such that the sidewalls of the ingot 10 are opposite to the sidewalls of the grinding wheel 30, and the bottom surface of the ingot 10 is parallel to the bottom surface of the grinding wheel 30. Thus, by moving the grinding wheel 30 and moving and rotating the ingot 10, the sidewalls of the ingot 10 are uniformly removed, forming a standard cylindrical ingot. Figure 4 This is a schematic side view of a conventional cylindrical grinding machine used to uniformly remove the sidewalls of the ingot 10 to be processed. Figure 4 The portion outside the two dotted lines is the part that was removed by the external cylindrical grinding machine.
[0058] contrast Figure 1 and Figure 4It is known that the bottom diameter of the ingot 10 to be processed is D1, and the thickness of the ingot 10 to be processed is z1. The bottom diameter of the standard cylindrical ingot after processing by the existing cylindrical grinding machine must be at least the target diameter D2. That is, the diameter of the standard cylindrical ingot after processing by the cylindrical grinding machine must meet the requirements. Therefore, the maximum amount of diameter that can be removed from the bottom surface of the ingot 10 to be processed along the radial direction is ΔD = D1 - D2. Since the existing cylindrical grinding machine processing uniformly removes the sidewalls of the ingot 10 to be processed, the maximum amount of radius that can be removed from the bottom surface of the ingot 10 to be processed along the radial direction is ΔD / 2 = (D1 - D2) / 2.
[0059] If the maximum depth of the obliquely growing defect on the sidewall of the ingot 10 to be processed is greater than ΔD / 2, then the effective thickness of the standard brick cylindrical ingot after processing by the existing cylindrical grinding machine will be reduced due to defects in part of its thickness, or it may be damaged during processing, affecting the processing yield and output of the ingot. It should be noted that the effective thickness of the ingot refers to the thickness of the part of the ingot without defects.
[0060] In view of this, embodiments of this application provide a crystal ingot processing method, which can be applied to silicon carbide crystal ingots, as well as crystal ingots of other materials, having defects grown obliquely or areas that need to be removed obliquely. The crystal ingot processing method includes:
[0061] S100: Reference Figure 1 As shown, a crystal ingot 10 to be processed is obtained. The crystal ingot 10 to be processed is cylindrical, with a bottom diameter of D1 and a thickness of z1.
[0062] Understandably, the grown crystal embryo can be processed into a cylindrical ingot 10 by means of planar machining and rough machining of the outer circle.
[0063] S200: Reference Figure 1 and Figure 5 As shown, defects on the ingot 10 to be processed are detected, the maximum depth h1 of the defect that penetrates from the sidewall to the central axis on the ingot 10 to be processed is determined, and the depth h2 of the defect that penetrates from the sidewall to the central axis in the region opposite to the maximum depth h1 in the bottom surface is determined, along the radial direction of the bottom surface, where the maximum depth h1 is located, and 0≤h2
[0064] Taking silicon carbide ingot 10 as an example, such as Figure 1 As shown, since growth defects such as cracks and impurities will move closer to the central axis of the silicon carbide ingot during the growth process, the maximum depth h1 of the deepest defect from the sidewall to the central axis on the ingot 10 to be processed is usually located on the top surface of the ingot 10 to be processed (i.e. the bottom surface after growth).
[0065] Understandably, once the deepest defect penetrating from the sidewall to the central axis on the ingot 10 to be processed is determined, and the maximum depth h1 of this defect is also determined, the depth h2 of the defect penetrating from the sidewall to the central axis in the region opposite to the maximum depth h1 in the bottom surface along the radial direction of the bottom surface can be determined. Optionally, such as... Figure 1 As shown, the maximum depth h1 is located on the upper bottom surface of the ingot 10 to be processed. Along the radial direction of the upper bottom surface of the ingot 10, there are no defects in the region opposite to the maximum depth h1, i.e., h2 = 0. Alternatively, as... Figure 5 As shown, in the bottom surface where the maximum depth h1 is located, there is a defect in the region opposite to the maximum depth h1 along the radial direction of the bottom surface, and the depth of the defect from the sidewall to the central axis is h2, and h2 > 0.
[0066] S300: Reference Figure 5 As shown, the maximum depth h1 is defined as the location of the maximum removal amount on the bottom surface where the maximum depth h1 is located. Based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, the minimum removal amount m on the bottom surface where the maximum depth h1 is located is determined, where D1-D2≥h1+m, and the location of the minimum removal amount is opposite to the location of the maximum removal amount along the radial direction of the bottom surface where the maximum depth h1 is located.
[0067] It is understandable that in order to remove the defect at the maximum depth h1, the maximum depth h1 can be defined as the location of the maximum removal amount on the bottom surface where the maximum depth h1 is located.
[0068] It is also understood that the diameter of the ingot after being processed by the cylindrical grinding machine must be at least the target diameter D2. Therefore, the maximum removable amount of the diameter of the bottom surface of the ingot 10 to be processed, along the radial direction, is ΔD = D1 - D2, and ΔD > h1. Since the maximum depth h1 has been defined as the location of the maximum removable amount on the bottom surface at the maximum depth h1, the maximum removable amount at the location opposite to the location of the maximum removable amount (i.e., the location of the minimum removable amount) in the radial direction on the bottom surface at the maximum depth h1 is (D1 - D2 - h1). Furthermore, as previously known, in the bottom surface at the maximum depth h1, the depth h2 of the defect penetrating from the sidewall to the central axis in the region opposite to the maximum depth h1 in the radial direction, 0 ≤ h2 < h1. Thus, based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, determining the minimum removable amount m on the bottom surface at the maximum depth h1 can include:
[0069] Compare the size of h2 with (D1-D2-h1);
[0070] If h2≤(D1-D2-h1), then determine the minimum removal amount m=h2 at the bottom surface where the maximum depth h1 is located;
[0071] If h2 > (D1 - D2 - h1), then the minimum removal amount m = (D1 - D2 - h1) is determined for the bottom surface where the maximum depth h1 is located.
[0072] In other words, given a fixed maximum removable amount ΔD of the diameter of the bottom surface of the ingot 10 to be processed, and the maximum depth h1 is defined as the location of the maximum removable amount on the bottom surface at the maximum depth h1, the maximum removable amount at the location opposite to the location of the maximum removable amount (i.e., the location of the minimum removable amount) in the radial direction on the bottom surface at the maximum depth h1 is (D1-D2-h1). If the depth h2 of the defect in the region opposite to the maximum depth h1 in the radial direction on the bottom surface at the maximum depth h1 is less than or equal to (D1-D2-h1), then the minimum removable amount m = h2 on the bottom surface at the maximum depth h1 is directly determined; otherwise, m = (D1-D2-h1).
[0073] S400: Reference Figure 5 and Figure 6 As shown, the ingot 10 to be processed is processed by an external cylindrical grinding machine using a grinding wheel 30. The grinding wheel 30 is cylindrical, and the sidewall of the ingot 10 to be processed is placed opposite to the sidewall of the grinding wheel 30. The bottom surface of the ingot 10 to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel 30, tanα=(h1-m) / z1. The maximum depth h1 is the tip position of the ingot 10 to be processed, thus obtaining a slanted cylindrical ingot. The bottom surface of the slanted cylindrical ingot is circular, and the sidewall of the slanted cylindrical ingot is inclined at an angle α relative to the high surface.
[0074] Understandably, in combination Figure 5 and Figure 6 As shown, when the ingot 10 to be processed is processed by the grinding wheel 30, the side wall of the ingot 10 to be processed is placed opposite to the side wall of the grinding wheel 30, and the bottom surface of the ingot 10 to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel 30, tanα=(h1-m) / z1, and the maximum depth h1 is the tip position of the ingot 10 to be processed, thereby realizing the oblique removal of the side wall of the ingot 10 to be processed and removing the defects that penetrate the deepest from the side wall to the central axis on the ingot 10 to be processed.
[0075] Figure 7 This diagram shows a side view of the oblique removal of the sidewall of the ingot 10 to be processed using the ingot processing method provided in the embodiments of this application, in comparison. Figure 4 and Figure 7 It is understood that, compared to existing cylindrical grinding machines which can only uniformly remove the sidewalls of ingots, the ingot processing method provided in this application embodiment can achieve oblique removal of the sidewalls of the ingot 10 to be processed, as follows:
[0076] Firstly, since the ingot processing method provided in this application embodiment involves obliquely removing the sidewall of the ingot 10 to be processed, more of the removal amount on the bottom surface of the ingot 10 can be allocated to the maximum depth h1 of the deepest defect on the ingot 10 from the sidewall towards the central axis. The removal amount at the position on the bottom surface opposite to the maximum depth h1 along the radial direction of the bottom surface is the minimum removal amount m.
[0077] Secondly, assuming that the maximum removable amount (ΔD=D1-D2) of the bottom diameter of the ingot 10 to be processed allows the existing cylindrical grinding machine to remove the maximum depth h1 of the defect that penetrates from the sidewall to the central axis on the ingot 10 to be processed, then, since the existing cylindrical grinding machine uniformly removes the sidewall of the ingot 10 to be processed, the removal amount of the bottom diameter of the ingot 10 to be processed is 2h1, and the bottom diameter of the processed standard cylindrical ingot is D2''=D1-2h1. However, using the ingot processing method provided in the embodiments of this application, the bottom diameter of the oblique cylindrical ingot obtained after processing the ingot 10 becomes D2'=D1-h1-m, since m D2'' is beneficial for improving the utilization rate of ingot materials.<h1>
[0078] To better understand this application, Figure 8 This diagram shows a bottom view of the ingot 10 to be processed, with the sidewalls obliquely removed using the ingot processing method provided in this application embodiment. Figures 5-8 As shown, it can be understood that since the ingot 10 to be processed is processed by the grinding wheel 30 using an oblique external cylindrical grinding machine, the bottom surface of the oblique cylindrical ingot obtained after processing is still circular. However, the sidewalls of the oblique cylindrical ingot obtained after processing have an inclination angle α relative to its height. Furthermore, it can be understood that in step S300, the maximum depth h1 is defined as the location of the maximum removal amount on the bottom surface at the maximum depth h1, and h2 or (D1-D2-h1) is defined as the minimum removal amount m on the bottom surface at the maximum depth h1. The minimum removal amount and the maximum removal amount are opposite each other along the radial direction of the bottom surface where the maximum depth h1 is located. This is so that in step S400, the side wall of the crystal ingot 10 to be processed is placed opposite the side wall of the grinding wheel 30, and the bottom surface of the crystal ingot 10 to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel 30, tanα=(h1-m) / z1. When the maximum depth h1 is the tip position of the crystal ingot 10 to be processed, the defects that penetrate the deepest from the side wall to the central axis on the crystal ingot 10 to be processed can be removed obliquely.
[0079] It is also understandable that, in combination Figures 5-8 As shown, since the ingot processing method provided in this application embodiment removes the sidewall of the ingot 10 to be processed obliquely, the removal situation on the two bottom surfaces of the ingot 10 to be processed is the same. However, on the other bottom surface opposite to the bottom surface where the maximum depth h1 is located, the removal amount corresponding to the maximum depth h1 is m, and the removal amount corresponding to m on the bottom surface where the maximum depth h1 is located on the other bottom surface is h1.
[0080] Based on the above embodiments, optionally, in some embodiments of this application, step S400, which involves external cylindrical grinding of the ingot 10 to be processed using the grinding wheel 30, may include:
[0081] S410: Reference Figure 5 and Figure 6 As shown, the clamping member 20 holds the ingot 10 to be processed through the auxiliary block 40, and refers to... Figure 9 and Figure 10As shown, the auxiliary block 40 includes a bottom surface and an inclined surface that is inclined relative to its bottom surface. The inclined surface of the auxiliary block 40 is in contact with the bottom surface of the ingot 10 to be processed. The bottom surface of the auxiliary block 40 is in contact with the clamping member 20. The line connecting the highest point A1 and the lowest point A2 of the inclined surface of the auxiliary block 40 to its bottom surface is parallel to the radial direction of the bottom surface of the ingot 10 to be processed where the maximum depth h1 is located. The center of the inclined surface and the bottom surface of the auxiliary block 40, the center of the bottom surface of the ingot 10 to be processed, and the central axis of the clamping member 20 are aligned, so that the side wall of the ingot 10 to be processed is placed opposite to the side wall of the grinding wheel 30. The bottom surface of the ingot 10 to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel 30, and the maximum depth h1 is the tip position of the ingot to be processed.
[0082] S420: By moving the grinding wheel 30 and moving and rotating the ingot 10 to be processed, the sidewall of the grinding wheel 30 is obliquely removed from the sidewall of the ingot 10 to be processed, resulting in an oblique cylindrical ingot. The bottom surface of the oblique cylindrical ingot is circular, and the sidewall of the oblique cylindrical ingot is inclined at an angle α relative to its height.
[0083] It is understandable that when the ingot 10 to be processed is machined by the grinding wheel 30, in order to make the bottom surface of the ingot 10 tilt at an angle α relative to the bottom surface of the grinding wheel 30, an auxiliary block 40 can be set between the clamping member 20 and the ingot 10 to be processed. The clamping member 20 and the auxiliary block 40 together ensure that the sidewall of the ingot 10 to be processed is placed opposite the sidewall of the grinding wheel 30, with the bottom surface of the ingot 10 tilting at an angle α relative to the bottom surface of the grinding wheel 30, and the maximum depth h1 being the tip of the ingot. Wherein, as Figure 9 and Figure 10 As shown, the auxiliary block 40 includes a bottom surface and an inclined surface that is inclined relative to its bottom surface. The inclined surface of the auxiliary block 40 is attached to the bottom surface of the ingot 10 to be processed, and the bottom surface of the auxiliary block 40 is attached to the clamping member 20. The line connecting the highest point and the lowest point of the inclined surface of the auxiliary block 40 from its bottom surface is parallel to the radial direction of the bottom surface of the ingot 10 to be processed where the maximum depth h1 is located. The center of the inclined surface and bottom surface of the auxiliary block 40, the center of the bottom surface of the ingot 10 to be processed, and the central axis of the clamping member 20 are aligned.
[0084] It is also understood that, optionally, the inclined surface of the auxiliary block 40 is inclined at an angle α relative to its bottom surface, so that the bottom surface of the auxiliary block 40 can be parallel to the bottom surface of the grinding wheel 30, but this application is not limited to this. Alternatively, the inclined surface of the auxiliary block 40 may not be inclined at an angle α relative to its bottom surface, for example, the inclination angle is less than α. In this case, the bottom surface of the ingot 10 to be processed may be inclined at an angle α relative to the bottom surface of the grinding wheel 30 by means of the inclined clamping member 20 together with the auxiliary block 40.
[0085] Alternatively, the auxiliary block 40 can be omitted, and the bottom surface of the ingot 10 to be processed can be tilted at an angle α relative to the bottom surface of the grinding wheel 30 by means of the tilting clamp 20 or the tilting grinding wheel 30, depending on the specific situation.
[0086] Based on the above-described auxiliary block 40, optionally, in some embodiments of this application, such as Figure 9 and Figure 10 As shown, the auxiliary block 40 can be in the shape of a truncated cylinder. The truncated cylinder can be seen as the shape after a cylinder is cut at an angle. The bottom surface of the auxiliary block 40 is a circular bottom surface, and the inclined surface of the auxiliary block 40 is an elliptical inclined surface. The line connecting the highest point A1 and the lowest point A2 of the inclined surface of the auxiliary block 40 relative to its bottom surface is the major axis of the elliptical inclined surface of the auxiliary block 40.
[0087] Optionally, in some embodiments of this application, before the ingot 10 to be processed is processed by external cylindrical grinding with grinding wheel 30, the ingot processing method may further include:
[0088] S500: Select auxiliary block 40, the inclined plane of the selected auxiliary block 40 is inclined at an angle α relative to its bottom surface, and the distance r between the inclined plane of the selected auxiliary block 40 and the highest and lowest points of its bottom surface is less than D2.
[0089] In this embodiment, when the clamping member 20 clamps the ingot 10 to be processed through the auxiliary block 40, the bottom surface of the auxiliary block 40 can be parallel to the bottom surface of the grinding wheel 30.
[0090] In this embodiment, the distance r < D2 between the inclined surface of the selected auxiliary block 40 and the highest and lowest points of its bottom surface is to prevent the grinding wheel 30 from wearing down the auxiliary block 40.
[0091] Further, optionally, in some embodiments of this application, the ingot processing method further includes:
[0092] S600: such as Figure 11 As shown, the oblique cylindrical ingot 11 is cut using a parallel line mesh 50. The extension direction of the parallel lines in the parallel line mesh 50 is parallel to the bottom surface of the oblique cylindrical ingot 11, and the arrangement direction of the parallel lines in the parallel line mesh is perpendicular to the bottom surface of the oblique cylindrical ingot, thus obtaining multiple oblique cylindrical wafers.
[0093] In existing technologies, such as Figure 12 As shown, the standard cylindrical ingot obtained after external cylindrical grinding is first pasted onto resin plate 60, and then resin plate 60 is pasted onto the worktable fixture 70 of multi-wire cutting machine; then refer to Figure 13 As shown, a standard cylindrical ingot is cut using the parallel wire mesh 50 of a multi-wire dicing machine to obtain multiple standard cylindrical wafers. It can be understood that, as... Figure 14As shown, when cutting a standard cylindrical ingot processed by an existing cylindrical grinding machine using a parallel line mesh 50, the extension direction of the parallel lines in the parallel line mesh 50 is parallel to the bottom surface of the standard cylindrical ingot, and the arrangement direction of the parallel lines in the parallel line mesh is perpendicular to the bottom surface of the standard cylindrical ingot.
[0094] In this application, reference is made to Figure 11 As shown, the oblique cylindrical ingot 11 is first attached to the resin plate 60, and then the resin plate 60 is attached to the worktable fixture 70 of the multi-wire cutting machine. The oblique cylindrical ingot 11 is then cut using the parallel wire mesh 50 of the multi-wire cutting machine. Unlike existing technologies, the parallel lines in the parallel wire mesh 50 extend parallel to the bottom surface of the oblique cylindrical ingot 11, and the arrangement direction of the parallel lines in the parallel wire mesh 50 is perpendicular to the bottom surface of the oblique cylindrical ingot, resulting in multiple oblique cylindrical wafers. It can be understood that the resulting multiple oblique cylindrical wafers are similar to the oblique cylindrical ingot 11, with a circular bottom surface and sidewalls at a relatively high tilt angle α; the only difference is that the oblique cylindrical wafers are thinner than the oblique cylindrical ingot 11.
[0095] If the oblique cylindrical ingot 11 processed by the external cylindrical grinding machine is a silicon carbide ingot, the oblique cylindrical ingot 11 can be pasted onto the resin plate 60 according to the calibration accuracy of the Si surface and the C surface, and then the resin plate 60 can be pasted onto the worktable fixture 70 of the multi-wire cutting machine, and the oblique cylindrical ingot 11 can be cut using the parallel wire mesh 50.
[0096] Further, optionally, in some embodiments of this application, the ingot processing method further includes:
[0097] S700: Chamfering is performed on the oblique cylindrical wafer to obtain a standard cylindrical wafer, wherein the thickness of the oblique cylindrical wafer is x, the diameter of the bottom surface of the oblique cylindrical wafer is D2, the skewness of the sidewall of the oblique cylindrical wafer is y=x tanα, the diameter of the bottom surface of the standard cylindrical wafer is D3, and (D2-D3)≥y.
[0098] It is understandable that, such as Figure 15 The oblique cylindrical wafer 12 shown has a diameter that remains unchanged relative to the oblique cylindrical ingot 11, that is, the diameter of the bottom surface of the oblique cylindrical wafer 12 is also D2. The thickness of the oblique cylindrical wafer 12 is reduced by x relative to the oblique cylindrical ingot 11. Since the sidewall of the oblique cylindrical wafer 12 is at a high tilt angle α, the deflection of the sidewall of the oblique cylindrical wafer is y = x tanα.
[0099] It is also understandable that when chamfering the oblique cylindrical wafer 12, the oblique amount of the sidewall of the oblique cylindrical wafer 12 (i.e., the edge bevel) can be removed, resulting in a cylindrical wafer of standard size and specifications. Specifically, such as Figure 15As shown, the diameter removal amount of the bottom surface of the inclined cylindrical wafer 12 during chamfering is n, n = (D2 - D3) = y + 2b, b ≥ 0. In order to ensure that the chamfering process removes the skewness of the sidewall of the inclined cylindrical wafer 12, n ≥ y, that is, (D2 - D3) ≥ y.
[0100] It should be noted that, as can be seen from the above analysis, the ingot processing method provided in this application embodiment can use existing processing equipment, such as external cylindrical grinding equipment, multi-wire cutting equipment, and chamfering equipment. The only difference is that when the obtained ingot 10 to be processed is processed by external cylindrical grinding, the ingot 10 is processed at an angle to the outer circle to obtain an oblique cylindrical ingot 11. Correspondingly, when the processed oblique cylindrical ingot 11 is processed by multi-wire cutting, the oblique cylindrical ingot 11 is cut into multiple oblique cylindrical wafers 12 in a manner parallel to the bottom surface of the oblique cylindrical ingot 11. Finally, the oblique cylindrical wafers 12 are chamfered normally to obtain wafers of standard size and specifications.
[0101] It should also be noted that the ingot processing method provided in this application embodiment is applicable to ingots 10 of various sizes to be processed. For example, the diameter of the bottom surface of the ingot 10 to be processed can be 2 inches, 3 inches, 4 inches, 6 inches or 8 inches, etc.
[0102] Based on the same inventive concept, this application also provides an ingot processing device. Figure 16 This application provides a schematic flowchart of an ingot processing apparatus, which includes:
[0103] The ingot acquisition device 100 is used to perform rough processing on the grown ingot to acquire the ingot to be processed 10. The ingot to be processed 10 is cylindrical, the diameter of the bottom surface of the ingot to be processed is D1, and the thickness of the ingot to be processed is z1.
[0104] The defect detection device 200 is used to detect defects on the ingot 10 to be processed, determine the maximum depth h1 of the defect that penetrates from the side wall to the central axis on the ingot 10 to be processed, and determine the depth h2 of the defect that penetrates from the side wall to the central axis in the region opposite to the maximum depth h1 in the bottom surface along the radial direction of the bottom surface, where 0≤h2
[0105] The computing device 300 defines the maximum depth h1 as the location of the maximum removal amount on the bottom surface where the maximum depth h1 is located, and determines the minimum removal amount m on the bottom surface where the maximum depth h1 is located based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, where D1-D2≥h1+m, and the location of the minimum removal amount is opposite to the location of the maximum removal amount along the radial direction of the bottom surface.
[0106] The external cylindrical grinding machine processing device 400 performs external cylindrical grinding on the crystal ingot 10 to be processed through the grinding wheel 30. The grinding wheel 30 is cylindrical, and the side wall of the crystal ingot 10 to be processed is placed opposite to the side wall of the grinding wheel 30. The bottom surface of the crystal ingot 10 to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel 30, tanα=(h1-m) / z1. The maximum depth h1 is the tip position of the crystal ingot to be processed, thereby obtaining a slanted cylindrical crystal ingot 11. The bottom surface of the slanted cylindrical crystal ingot 11 is circular, and the side wall of the slanted cylindrical crystal ingot is inclined at an angle α relative to the bottom surface of the grinding wheel 30.
[0107] Optionally, the ingot acquisition device 100 and the external cylindrical grinding machine processing device 400 can be the same external cylindrical grinding machine processing device. That is, the external cylindrical grinding machine processing device first performs rough external cylindrical grinding on the grown ingot to obtain the ingot to be processed 10, and then performs fine external cylindrical grinding on the ingot to be processed 10 to obtain the oblique cylindrical ingot 11.
[0108] Further optional, in some embodiments of this application, such as Figure 16 As shown, the ingot processing equipment may further include:
[0109] The multi-wire cutting device 500 uses a parallel wire mesh 50 to cut the oblique cylindrical ingot 11. The extension direction of the parallel lines in the parallel wire mesh 50 is parallel to the bottom surface of the oblique cylindrical ingot 11, and the arrangement direction of the parallel lines in the parallel wire mesh 11 is perpendicular to the bottom surface of the oblique cylindrical ingot 11, thereby obtaining multiple oblique cylindrical wafers 12.
[0110] It is understandable that the multi-wire cutting device 500 can be a multi-wire cutting machine.
[0111] Further optional, in some embodiments of this application, such as Figure 16 As shown, the ingot processing equipment may further include:
[0112] The chamfering processing device 600 performs chamfering processing on the oblique cylindrical wafer 12 to obtain a standard cylindrical wafer. The thickness of the oblique cylindrical wafer 12 is x, the diameter of the bottom surface of the oblique cylindrical wafer 12 is D2, the skewness of the sidewall of the oblique cylindrical wafer 12 is y=x tanα, the diameter of the bottom surface of the standard cylindrical wafer 12 is D3, and (D2-D3)≥y.
[0113] Since the ingot processing equipment provided in this application corresponds to the ingot processing method provided in this application, and the ingot processing method provided in this application has been described in detail in the foregoing embodiments, the ingot processing equipment provided in this application can be referred to the foregoing analysis and will not be described again.
[0114] The various parts of this manual are described in a combination of parallel and progressive methods. Each part focuses on the differences between the other parts, and the same or similar parts can be referred to each other.
[0115] The features described above regarding the disclosed embodiments can be substituted or combined with each other to enable those skilled in the art to implement or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for processing crystal ingots, characterized in that, The ingot processing method includes: Obtain a crystal ingot to be processed, the crystal ingot to be processed is cylindrical, the diameter of the bottom surface of the crystal ingot to be processed is D1, and the thickness of the crystal ingot to be processed is z1; Detect defects on the ingot to be processed, determine the maximum depth h1 of the defect that penetrates from the sidewall to the central axis on the ingot to be processed, and determine the depth h2 of the defect that penetrates from the sidewall to the central axis in the region opposite to the maximum depth h1 in the bottom surface along the radial direction of the bottom surface, where 0≤h2<h1. The maximum depth h1 is defined as the location of the maximum removal amount on the bottom surface where the maximum depth h1 is located. Based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, the minimum removal amount m on the bottom surface where the maximum depth h1 is located is determined, where D1-D2≥h1+m, and the location of the minimum removal amount is opposite to the location of the maximum removal amount along the radial direction of the bottom surface where the maximum depth h1 is located. The ingot to be processed is processed by an external cylindrical grinding machine using a grinding wheel, wherein the grinding wheel is cylindrical, the sidewall of the ingot to be processed is placed opposite the sidewall of the grinding wheel, the bottom surface of the ingot to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel, tanα=(h1-m) / z1, and the maximum depth h1 is the tip position of the ingot to be processed, thereby obtaining a slanted cylindrical ingot, the bottom surface of the slanted cylindrical ingot is circular, and the sidewall of the slanted cylindrical ingot is inclined at an angle α relative to the high surface.
2. The ingot processing method according to claim 1, characterized in that, Based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, the minimum removal amount m of the bottom surface where the maximum depth h1 is located is determined by: Compare the size of h2 with (D1-D2-h1); If h2≤(D1-D2-h1), then determine the minimum removal amount m=h2 at the bottom surface where the maximum depth h1 is located; If h2 > (D1 - D2 - h1), then determine the minimum removal amount m = (D1 - D2 - h1) of the bottom surface where the maximum depth h1 is located.
3. The ingot processing method according to claim 1, characterized in that, The external cylindrical grinding of the ingot to be processed by a grinding wheel includes: The clamping member holds the ingot to be processed by an auxiliary block. The auxiliary block includes a bottom surface and an inclined surface at an angle α relative to its bottom surface. The inclined surface of the auxiliary block is in contact with the bottom surface of the ingot to be processed. The bottom surface of the auxiliary block is in contact with the clamping member. The line connecting the highest and lowest points of the inclined surface of the auxiliary block and its bottom surface is parallel to the radial direction of the bottom surface of the ingot to be processed where the maximum depth h1 is located. The center of the inclined surface and bottom surface of the auxiliary block, the center of the bottom surface of the ingot to be processed, and the central axis of the clamping member are aligned, so that the side wall of the ingot to be processed is placed opposite the side wall of the grinding wheel. The bottom surface of the ingot to be processed is at an angle α relative to the bottom surface of the grinding wheel, and the maximum depth h1 is the tip position of the ingot to be processed. By moving the grinding wheel and moving and rotating the ingot to be processed, the sidewall of the grinding wheel is obliquely removed from the sidewall of the ingot to be processed, resulting in an oblique cylindrical ingot with a circular bottom surface and the sidewall of the oblique cylindrical ingot at a high tilt angle α.
4. The ingot processing method according to claim 3, characterized in that, Before the ingot to be processed is machined by an external cylindrical grinding machine using a grinding wheel, the ingot processing method further includes: The auxiliary block is selected such that the elliptical inclined surface of the selected auxiliary block is inclined at an angle α relative to its circular base, and the distance r between the inclined surface of the selected auxiliary block and the highest and lowest points of its base is less than D2. When the clamping component holds the ingot to be processed through the auxiliary block, the circular bottom surface of the auxiliary block is parallel to the bottom surface of the grinding wheel.
5. The ingot processing method according to claim 1, characterized in that, The ingot processing method further includes: The oblique cylindrical ingot is cut using a parallel line mesh, wherein the extension direction of the parallel lines in the parallel line mesh is parallel to the bottom surface of the oblique cylindrical ingot, and the arrangement direction of the parallel lines in the parallel line mesh is perpendicular to the bottom surface of the oblique cylindrical ingot, thereby obtaining multiple oblique cylindrical wafers.
6. The ingot processing method according to claim 5, characterized in that, The ingot processing method further includes: The oblique cylindrical wafer is chamfered to obtain a standard cylindrical wafer, wherein the thickness of the oblique cylindrical wafer is x, the diameter of the bottom surface of the oblique cylindrical wafer is D2, the skewness of the sidewall of the oblique cylindrical wafer is y=xtanα, the diameter of the bottom surface of the standard cylindrical wafer is D3, and (D2-D3)≥y.
7. The ingot processing method according to any one of claims 1-6, characterized in that, The ingot processing method is applied to silicon carbide ingots.
8. A crystal ingot processing equipment, characterized in that, The ingot processing equipment includes: A crystal ingot acquisition device is used to perform rough processing on the grown crystal embryo to obtain a crystal ingot to be processed. The crystal ingot to be processed is cylindrical, the diameter of the bottom surface of the crystal ingot to be processed is D1, and the thickness of the crystal ingot to be processed is z1. A defect detection device is used to detect defects on the ingot to be processed, determine the maximum depth h1 of the defect that penetrates from the sidewall to the central axis on the ingot to be processed, and determine the depth h2 of the defect from the sidewall to the central axis in the region opposite to the maximum depth h1 in the bottom surface along the radial direction of the bottom surface, where 0≤h2<h1. The computing device defines the maximum depth h1 as the location of the maximum removal amount on the bottom surface where the maximum depth h1 is located, and determines the minimum removal amount m on the bottom surface where the maximum depth h1 is located based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, where D1-D2≥h1+m, and the location of the minimum removal amount is opposite to the location of the maximum removal amount along the radial direction of the bottom surface. An external cylindrical grinding machine processing device performs external cylindrical grinding on a crystal ingot to be processed using a grinding wheel. The grinding wheel is cylindrical, and the sidewall of the crystal ingot to be processed is placed opposite the sidewall of the grinding wheel. The bottom surface of the crystal ingot to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel, where tanα=(h1-m) / z1. The maximum depth h1 is the tip position of the crystal ingot to be processed, thereby obtaining a slanted cylindrical crystal ingot. The bottom surface of the slanted cylindrical crystal ingot is circular, and the sidewall of the slanted cylindrical crystal ingot is inclined at an angle α relative to the high surface.
9. The ingot processing equipment according to claim 8, characterized in that, The ingot processing equipment also includes: A multi-wire cutting device uses a parallel wire mesh to cut the oblique cylindrical crystal ingot. The extension direction of the parallel wire mesh is parallel to the bottom surface of the oblique cylindrical crystal ingot, and the arrangement direction of the parallel wire mesh is perpendicular to the bottom surface of the oblique cylindrical crystal ingot, thereby obtaining multiple oblique cylindrical wafers.
10. The ingot processing equipment according to claim 9, characterized in that, The ingot processing equipment also includes: A chamfering processing device performs chamfering processing on the oblique cylindrical wafer to obtain a standard cylindrical wafer, wherein the thickness of the oblique cylindrical wafer is x, the diameter of the bottom surface of the oblique cylindrical wafer is D2, the skewness of the sidewall of the oblique cylindrical wafer is y=xtanα, the diameter of the bottom surface of the standard cylindrical wafer is D3, and (D2-D3)≥y.