SiC material turning tool and manufacturing method

Abstract

The invention relates to a SiC material turning tool and a manufacturing method thereof, and the manufacturing method comprises the following steps: S1, preparing a SiC crystal in accordance with the size, the size range of the diameter of the SiC crystal is 50-150mm, and the thickness of the SiC crystal is 5-15mm; s2, the crystal is subjected to multi-line fretsaw cutting, the purpose is to manufacture a cutter body shape, mortar line distance cutting can be selected as a fretsaw cutting mode, the SiC crystal is bonded to a glass plate firstly and then fixed to a machine table working area, fretsaw machining is conducted through steel wire swinging, and the line distance is set to be 4-8 mm; the linear speed is set to be 10 m / s to 30 m / s; the tension of the steel wire is set to be 30N-50N; the cutter body is roughly machined. When a traditional turning tool is used for machining a graphite product, impurity atoms remain on the graphite product due to friction, the procedures of purification, ultrasonic washing and drying and the like need to be carried out subsequently, a large amount of cost is increased, cutting equipment can be used in the procedures, and cooling liquid used by existing cutting equipment needs to be purified.

Description

Technical Field

[0001] The invention belongs to the field of turning tool manufacturing, and in particular relates to a SiC material turning tool and a manufacturing method thereof. Background Art

[0002] Silicon carbide is considered to be one of the most important wide bandgap semiconductor materials, with superior properties such as large bandgap width, high breakdown electric field, high thermal conductivity, high electron saturation rate, and strong radiation resistance. Semiconductor devices based on SiC materials can not only operate stably at higher temperatures, but also have higher reliability under high voltage and high frequency conditions. In the past 20 years, with the rapid development of SiC material growth technology, manufacturing processes and device physics, SiC materials and devices have been widely used in radar, 5G communications, electric vehicles and other fields, which have had an extremely important impact on the development of the national defense industry, national information security, and national economic construction. In the SiC-based high-power semiconductor device industry chain, the preparation of high-quality SiC single crystals and their industrialization are the most important links.

[0003] Impurities introduced during the growth of SiC crystals will affect the spontaneous nucleation of crystal growth; the higher the impurity content, the less likely it is for the spontaneous nucleation of the crystal. For SiC, the main metal impurities include B, Al, V, and Ni, which may be introduced by processing tools during the processing of raw materials and graphite products; among them, B and Al are the main shallow energy level acceptor impurities in SiC, resulting in a decrease in SiC resistivity; other metal impurities will introduce many energy levels, resulting in unstable electrical properties of SiC single crystals at high temperatures, and have a great impact on the electrical properties of the SiC substrate, especially the resistivity; the growth process of the SiC substrate requires a large number of graphite products, so the purity of the graphite products is an important link affecting the quality of the SiC substrate; turning tools are usually used for processing graphite products. Currently, popular turning tools are divided into high-speed steel turning tools, ceramic tools, carbide turning tools, and cubic boron nitride turning tools according to their materials. These turning tools will leave impurities when in contact with graphite products.

[0004] The purpose of the present invention is to solve the problem of impurities introduced by conventional turning tools when processing graphite products required for the growth of SiC substrates. When conventional turning tools process graphite products, friction will cause impurity atoms to remain on the graphite products, and subsequent purification, ultrasonic washing and drying and other processes are required, which increases a lot of costs. During this period, cutting equipment is also used. The coolant used in existing cutting equipment needs to be purified, which increases the cost of use. However, if unpurified water is used, it will cause scale and impurities to accumulate, which will greatly reduce the cooling effect. Therefore, a SiC material turning tool and a manufacturing method are proposed. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the following technical problems in the prior art: when traditional turning tools process graphite products, friction will cause impurity atoms to remain on the graphite products, which require subsequent purification, ultrasonic washing and drying and other processes, which increase a lot of costs. Cutting equipment will also be used during this period. The coolant used in the existing cutting equipment needs to be purified, which increases the cost of use. However, if unpurified water is used, it will cause scale and impurities to accumulate, which will greatly reduce the cooling effect.

[0007] The turning tool is a mechanical clamping turning tool, and the material of the turning tool is SiC.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: a SiC material turning tool and a manufacturing method:

[0009] The SiC material turning tool manufacturing process of the present invention comprises the following steps:

[0010] S1: Prepare a SiC crystal of the right size, the diameter of the SiC crystal ranges from 50 mm to 150 mm, and the thickness ranges from 5 mm to 15 mm;

[0011] S2: Use a wire saw to cut the crystal with multiple wires to preliminarily produce the shape of the blade. The wire saw cutting method can be selected from mortar wire spacing cutting;

[0012] First, the SiC crystal is bonded to a glass plate, then fixed to the machine work area, and wire sawing is performed by swinging the steel wire;

[0013] The line spacing is set to 4mm~8mm; the line speed is set to 10m / s~30m / s; the steel wire tension is set to 30N~50N;

[0014] Since the tool body is rough-processed, in order to increase the processing speed, the feed speed is set to 2mm / h~3mm / h, the mortar can be mixed with SiC micropowder / diamond and suspension polyethylene glycol, the mortar particle size is controlled at 15~25μm, the mortar concentration is 600ct / L, and cutting oil is used for cooling during the processing, and the nozzle flow rate is 1.5L / min;

[0015] S3: The processed blade body is processed by cutting with a single-wire wire saw, and the angle α is 30° to 90°. Since the blade processing here requires fine processing to ensure surface flatness, the feed speed is set to 1.3 mm / h to 1.5 mm / h, and the mortar particle size is controlled at 5 to 10 μm;

[0016] S4: Because SiC has high hardness, it is difficult to process it into complex shapes using conventional processing methods. In order to produce the front angle γ0 and the back angle α0 of the turning tool, a SiC turning tool clamp is made to have the corresponding angles, such as Figure 4 As shown, the angle β is 80° to 90°; the clamping nesting material is stainless steel or hard plastic, and the turning tool is clamped by two nestings. In order to ensure that the turning tool does not shake during use, the size of the nesting a is required to be ~1.5mm. At the same time, by making nestings with different angles β, the corresponding front angle γ0 and back angle α0 can be obtained to meet the actual use requirements;

[0017] S5: Schematic diagram of graphite machining with SiC turning tool, the back angle α0 is 1°~10°, and the front angle γ0 is 5°~20°;

[0018] S6: The finished turning tool is ultrasonically cleaned and dried in a drying oven set at 50°C.

[0019] As an optimal technical solution for a SiC material turning tool and a manufacturing method, the wire cutting machine includes a support base 1, an intermediate seat, a cutting wire, a tensioning roller, a support base 2, a cooling cylinder, a driving member and a drainage assembly. The middle part of the top of the support base 1 is provided with an intermediate seat, the top of the intermediate seat is rotatably connected to a tensioning roller, and two sides of the support base 1 are respectively provided with a support base 2, the support base 2 is rotatably connected to a cooling cylinder, and the cutting wire is sleeved on the outer periphery of the cooling cylinder and the tensioning roller;

[0020] A side plate and a stabilizing plate are installed on the top of the supporting base two, and the side plate is installed at one end of the supporting base two. An outer ring is installed at both ends of the cooling cylinder respectively. Four stabilizing plates are screwed on the top of the supporting base two, and an annular groove is reserved on the stabilizing plate. The annular groove of the limiting plate is movably connected to the outer ring. Every two stabilizing plates match the same outer ring. The two stabilizing plates are respectively located on both sides of the outer ring. The stabilizing plates can help maintain the posture of the outer ring and the cooling cylinder unchanged during rotation.

[0021] The SiC material turning tool and the manufacturing method of the present invention have the following beneficial effects: in the SiC substrate growth stage, the graphite products are processed by using a special SiC turning tool without residual impurity elements, which can improve the purity of the output SiC substrate and improve the yield of the SiC substrate and subsequent processes;

[0022] The invention has the advantages that SiC turning tools are processed from scrapped SiC crystals, which reduces production losses. After the graphite products used for SiC growth are processed, there is no need to perform a secondary purification process on subsequent graphite products, which saves costs.

[0023] By using spiral blades, scale and solid impurities entering the cooling cylinder can be partially left on the inner wall of the cooling cylinder under the blocking of the baffle. Then the cooling cylinder rotates to the position in contact with the shovel mechanism, during which the shovel will peel off the scale and solid impurities. After the scale and solid impurities are precipitated, they are transported away by the spiral blades in an efficient and rapid manner, thus preventing the scale and solid impurities from affecting the operation of the device and the cooling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0025] Figure 1 It is a schematic diagram of the three-dimensional structure of the cooling assembly of the present invention;

[0026] Figure 2 It is a schematic cross-sectional structural diagram of the front side of the present invention;

[0027] Figure 3 It is a schematic diagram of the internal structure of the spiral blade of the present invention;

[0028] Figure 4 It is a schematic diagram of the overall structure of the present invention;

[0029] Figure 5 This is a schematic diagram of the positional relationship between the outer ring and the gear of the present invention;

[0030] Figure 6 A top view of a cut crystal ingot of the present invention;

[0031] Figure 7 A side view of a cut ingot of the present invention;

[0032] Figure 8 It is a schematic diagram of the overall structure of the turning tool of the present invention;

[0033] Fig. 9 is a schematic diagram of the angle β of the present invention;

[0034] Fig.10 Schematic diagram of the angle α of the present invention.

[0035] Figure numerals: 1. Support base one; 2. Placement seat; 3. Intermediate seat; 4. Cutting line; 5. Tensioning roller; 12. Support base two; 13. Cooling cylinder; 14. Driving member; 15. Stabilizing disk; 16. Outer ring; 17. Liquid injection hole; 18. Air pressure hole; 19. Cover plate; 21. Side plate; 22. Trough body; 24. Spiral blade; 25. Discharge cylinder; 26. Baffle; 27. Shoveling platform; 28. Shoveling mechanism; 29. ​​Gear. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0037] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0038] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0039] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0040] like Figures 1 to 10 As shown, the present invention provides a SiC material turning tool and a manufacturing method thereof, and the turning tool manufacturing process includes the following steps:

[0041] S1: Prepare a SiC crystal of the appropriate size. The diameter of the SiC crystal ranges from 50 mm to 150 mm and the thickness ranges from 5 mm to 15 mm. Figure 6 and 7 As shown;

[0042] S2: Use a wire saw to perform multi-wire sawing on the SiC crystal to produce the shape of the blade. The wire sawing method can be selected as mortar line spacing cutting. First, the SiC crystal is bonded to the glass plate, and then fixed in the working area of ​​the machine. The wire sawing is performed by swinging the steel wire. The line spacing is set to 4mm~8mm; the line speed is set to 10m / s~30m / s; the steel wire tension is set to 30N~50N; because the blade is rough-processed, in order to increase the processing speed, the feed speed is set to 2mm / h~3mm / h. The mortar can be mixed with SiC micropowder / diamond and suspension polyethylene glycol. The mortar particle size is controlled at 15~25μm, the mortar concentration is 600ct / L, and cutting oil is used for cooling during the processing. The nozzle flow rate is 1.5L / min. At this time, the processed blade is as follows Figure 8 As shown;

[0043] S3: Process the blade of the machined cutter body by cutting with a single-wire saw at an angle of 30° to 90°. Fig. 9 As shown;

[0044] Since the blade processing here requires fine processing to ensure surface flatness, the feed speed is set to 1.3mm / h~1.5mm / h, and the mortar particle size is controlled at 5~10μm;

[0045] S4: Because SiC has high hardness, it is difficult to process it into complex shapes using conventional processing methods. In order to produce the front angle γ0 and the back angle α0 of the turning tool, a SiC turning tool clamp is made to have the corresponding angles, such as Fig.10 As shown, the angle β is 80° to 90°; the clamping nest is made of stainless steel or hard plastic, and the turning tool is clamped by two nests. To ensure that the turning tool does not shake during use, the size of the nest a is required to be half of the thickness of the turning tool to 1.5 mm. At the same time, the corresponding front angle γ0 and back angle α0 can be obtained by making nests with different angles β to meet the actual use requirements;

[0046] S5: Schematic diagram of graphite processing by SiC turning tool, such as Fig.10 As shown, the rear angle α0 is 1° to 10°, and the front angle γ0 is 5° to 20°;

[0047] S6: The finished turning tool is ultrasonically cleaned and dried in a drying oven set at 50°C.

[0048] When a wire saw is used to cut SiC crystals using multiple wires, a large amount of heat will be generated. The existing cooling method is to directly use water to cool the cutting wires, which will cause the cutting wires to stick to the "SiC crystal powder generated by cutting" and cause a large amount of water resource pollution and waste. Therefore, the water cannot be directly recycled.

[0049] The wire cutting machine for cutting SiC crystals comprises a support base 1, an intermediate base 3, a cutting wire 4, a tensioning roller 5, a support base 2 12, a cooling cylinder 13, a driving member 14 and a drainage assembly, wherein the middle portion of the top of the support base 1 is provided with an intermediate base 3, the top of the intermediate base 3 is rotatably connected with a tensioning roller 5, two sides of the support base 1 are respectively provided with a support base 2 12, the support base 2 12 is rotatably connected with a cooling cylinder 13, and the cutting wire 4 is sleeved on the outer periphery of the cooling cylinder 13 and the tensioning roller 5;

[0050] A side plate 21 and a stabilizing disk 15 are installed on the top of the supporting base 12. The side plate 21 is installed at one end of the supporting base 12. An outer ring 16 is installed at both ends of the cooling cylinder 13. Four stabilizing disks 15 are screwed on the top of the supporting base 12. An annular groove is reserved on the stabilizing disk 15. The annular groove of the limiting disk is movably connected to the outer ring 16. Every two stabilizing disks 15 match the same outer ring 16. The two stabilizing disks 15 are respectively located on both sides of the outer ring 16. The stabilizing disk 15 can help maintain the posture of the outer ring 16 and the cooling cylinder 13 unchanged during rotation.

[0051] The driving member 14 includes a motor and a transmission assembly. The driving member 14 is connected to one end of the cooling cylinder 13 . When the cooling cylinder 13 rotates, the other end of the cooling cylinder 13 is connected to the side plate 21 .

[0052] The drainage assembly includes a trough body 22 and a spiral blade 24. The trough body 22 is fixedly connected to the side plate 21. One end of the trough body 22 extends into the cooling cylinder 13. The bottom of the other end of the trough body 22 is fixedly connected to the discharge cylinder 25. The head of the discharge cylinder 25 is connected to the trough body 22. A connecting rod is installed on the inner side of the spiral blade 24. A motor is connected to the spiral blade 24. The power head of the motor is connected to the connecting rod. The spiral blade 24 transports the liquid in the cooling cylinder 13 out and then discharges it using the spiral blade 24. The trough body 22 collects the water dripping from the top of the inner cavity of the cooling cylinder 13.

[0053] A baffle 26 is installed on one side of the trough body 22, and a shovel platform 27 is installed on the other side of the trough body 22. A shovel mechanism 28 is installed on the shovel platform 27. The shovel mechanism 28 is movably connected to the inner wall of the cooling cylinder 13. A shovel is installed in the shovel mechanism 28, and the shovel is always movably connected to the inner wall of the cooling cylinder 13.

[0054] The side plate 21 is provided with a liquid injection hole 17, and the liquid injection hole 17 is located above the baffle 26. The bottom of the baffle 26 does not contact the inner wall of the cooling cylinder 13. Scale and solid impurities usually accumulate in the cooling cylinder 13, but can be shoveled away by the shoveling mechanism 28. The baffle 26 can block the cleaned scale and solid impurities.

[0055] The top and bottom of the side plate 21 are both recessed with air pressure holes 18. A cover plate 19 is also installed on the side plate 21. The middle of the supporting base 1 is movably connected with a placement seat 2. The bottom of the placement seat 2 is threadedly connected with a screw rod or a hydraulic cylinder, which can control the placement seat 2 to move up and down.

[0056] A gear 29 is arranged at the power output end of the motor, and connecting teeth are arranged on the inner side of the outer ring 16, and the gear 29 is engaged with the connecting teeth.

[0057] The specific implementation method is as follows: cooling water is injected through the injection hole 17 and the slot body 22 is staggered. The water cools the shell of the cooling cylinder 13, and the cutting line 4 is cooled and cooled down. The motor drives the outer ring 16 of the wire cutting machine and the cooling cylinder 13 to rotate through the gear 29, and the crystal is placed on the placement seat 2. The placement seat 2 is controlled to move the crystal upward to contact the cutting line 4, and the crystal is cut using the cutting line 4. The water at the bottom of the cooling cylinder 13 does not cover the upper edge of the slot body 22, and the water that has absorbed the heat of the cooling cylinder 13 falls into the slot body 22.

[0058] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0059] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A SiC material turning tool and a manufacturing method, characterized in that: The turning tool manufacturing process includes the following steps: S1: Prepare a SiC crystal of the right size, the diameter of the SiC crystal ranges from 50 mm to 150 mm, and the thickness ranges from 5 mm to 15 mm; S2: Use a wire saw to cut the SiC crystal with multiple wires to produce the shape of the blade. The wire saw cutting method can be mortar wire spacing cutting. First, the SiC crystal is bonded to the glass plate, and then fixed in the working area of ​​the machine. The wire sawing is performed by swinging the steel wire. The wire spacing is set to 4mm~8mm; the wire speed is set to 10m / s~30m / s; The wire tension is set to 30N~50N; because the tool body is rough-processed, the feed speed is set to 2mm / h~3mm / h to increase the processing speed. The mortar can be mixed with SiC micropowder / diamond and suspension polyethylene glycol. The mortar particle size is controlled at 15~25μm, and the mortar concentration is 600ct / L. Cutting oil is used for cooling during the processing, and the nozzle flow rate is 1.5L / min. S3: The processed blade body is processed by cutting with a single-wire wire saw, and the angle α is 30° to 90°, as shown in FIG3 ; since the blade processing here requires fine processing to ensure surface flatness, the feed speed is set to 1.3 mm / h to 1.5 mm / h, and the mortar particle size is controlled at 5 to 10 μm; S4: Because SiC has a high hardness, it is difficult to process it into complex shapes using conventional processing methods. In order to produce the front angle γ0 and the back angle α0 of the turning tool, a SiC turning tool clamping nest is made to have a corresponding angle, and the angle β is 80° to 90°; the clamping nest is made of stainless steel or hard plastic, and the turning tool is clamped by two nests. In order to ensure that the turning tool does not shake during use, the size of the nest a is required to be (half the thickness of the turning tool) to 1.5 mm. At the same time, the corresponding front angle γ0 and back angle α0 can be obtained by making nests with different angles β to meet actual use requirements; S5: Graphite machining with SiC turning tool, the back angle α0 is 1°~10°, and the front angle γ0 is 5°~20°; S6: The finished turning tool is ultrasonically cleaned and dried in a drying oven set at 50°C.

2. A SiC material turning tool and manufacturing method according to claim 1, characterized in that: The turning tool is a mechanical clamping turning tool, and the material of the turning tool is SiC.

3. A SiC material turning tool and manufacturing method according to claim 1, characterized in that: The wire cutting machine for cutting SiC crystals comprises a support base (1), an intermediate base (3), a cutting wire (4), a tensioning roller (5), a support base (12), a cooling cylinder (13), a driving member (14) and a drainage assembly. The middle part of the top of the support base (1) is provided with an intermediate base (3), the top of the intermediate base (3) is rotatably connected to a tensioning roller (5), two sides of the support base (1) are respectively provided with a support base (12), the support base (12) is rotatably connected to a cooling cylinder (13), and the cutting wire (4) is sleeved on the outer periphery of the cooling cylinder (13) and the tensioning roller (5).

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