Double-wire cutting tool and method for 12-inch silicon carbide cutting disc

Abstract

The invention discloses a double-wire cutting tool and method for a 12-inch silicon carbide cutting disc, solves the problem that a cutting device in the prior art is not suitable for cutting the 12-inch silicon carbide cutting disc, and has the beneficial effects that the cutting quality is ensured, and the double-wire cutting tool and method are suitable for obtaining the 12-inch silicon carbide cutting disc. According to the specific scheme, the double-wire cutting tool for the 12-inch silicon carbide cutting disc comprises two cutting wheels, the two cutting wheels are arranged at intervals, at least two wire grooves are formed in the circumferential direction of each cutting wheel, and two diamond wires are wound around the two cutting wheels through the wire grooves of the two cutting wheels so as to form the two parallel diamond wires; the connecting fixing part is detachably connected with the crystal disc, a silicon carbide wafer is bonded to the end face of the crystal disc, a silicon carbide ingot is bonded to the end face of the silicon carbide wafer and the end face of the crystal disc, the diameter of the silicon carbide wafer is smaller than that of the silicon carbide ingot so that the silicon carbide ingot can be prevented from cracking, and the distance between the close faces of the two cutting wheels is larger than the diameter of the crystal disc.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicon carbide diamond wire cutting, in particular to a double-wire cutting tool and method for 12-inch silicon carbide cutting wafers. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] As the third-generation wide-bandgap semiconductor material, silicon carbide (SiC) has high breakdown field strength, high thermal conductivity, high electron mobility, and excellent chemical stability, and is the core substrate for manufacturing high-frequency, high-temperature, and high-voltage power devices (such as insulated gate bipolar transistors (IGBT) and metal-oxide-semiconductor transistors (MOSFET)) and radio frequency devices, and is widely used in strategic emerging fields such as new energy vehicles, rail transit, smart grid, and 5G communication. At present, silicon carbide wafers are mainly 6 / 8 inches, and 12-inch silicon carbide wafers have become the mainstream research and development direction in the industry. However, silicon carbide is a typical "hard and brittle difficult-to-machine material", with a Mohs hardness of 9.2 (second only to diamond), and especially 12-inch ultra-large-size single crystals require higher requirements for processing equipment and technology during the processing.

[0004] Etching of silicon carbide wafers is a method for detecting the growth conditions of silicon carbide ingots. After cutting, the wafers are thinned to remove the cutting damage layer, and then polished to obtain a low-roughness surface. Finally, the dislocation of the etched wafer is observed by strong alkali etching, so as to determine the quality of the silicon carbide ingot.

[0005] Therefore, it is necessary to cut the silicon carbide diamond wire. The existing silicon carbide diamond wire cutting technology is mainly multi-wire cutting technology and single-wire cutting technology. The multi-wire cutting technology constructs a closed-loop steel wire mesh through a wire feeding roller, a transition roller, and a wire guide roller, and cuts the entire silicon carbide ingot. When detecting the dislocation of the silicon carbide ingot using this multi-wire cutting technology, the entire silicon carbide ingot will be damaged, the silicon carbide ingot is prone to cracking, which makes it impossible to accurately determine the quality of the silicon carbide ingot, and the research and development cost is increased. The single-wire cutting technology cuts the silicon carbide ingot with a single wire. Cutting a piece of silicon carbide ingot requires cutting twice, which is low in overall cutting efficiency and difficult to control the thickness of the cut silicon carbide wafer, and cannot meet the precision requirements of the etching cutting wafer. The above two methods have the above problems for smaller size silicon carbide cutting. It is more difficult to cut larger size silicon carbide such as 12 inches. SUMMARY

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a dual-wire cutting fixture for 12-inch silicon carbide wafers, which solves problems such as inaccurate wafer thickness control, low processing efficiency, and easy crystal cracking in existing technologies. By using parallel dual-wire cutting, the distance between the two wires can be accurately controlled, and the cut wafers can meet the precision requirements of etched wafers.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: A dual-wire cutting fixture for a 12-inch silicon carbide dicing blade includes: Two cutting wheels are set at a distance from each other. Each cutting wheel has at least two grooves in its circumferential direction. Two diamond wires pass through the grooves of the two cutting wheels and are set around the two cutting wheels to form two parallel diamond wires. The crystal disk is detachably connected to the connecting fastener. A silicon carbide wafer is bonded to the end face of the crystal disk. A silicon carbide ingot is bonded to the silicon carbide wafer and the end face of the crystal disk. The diameter of the silicon carbide wafer is smaller than the diameter of the silicon carbide ingot to avoid cracking of the silicon carbide ingot. The distance between the close surfaces of the two cutting wheels is greater than the diameter of the crystal disk. The cutting equipment is connected to both cutting wheels via a lifting mechanism, and the cutting equipment is connected to the connecting fixing parts via a moving mechanism.

[0008] As described above, a dual-wire cutting fixture for a 12-inch silicon carbide wafer is provided, wherein the bottom of the silicon carbide wafer is supported by a support block, the support block is in contact with the end face of the wafer, the support block is bonded to the silicon carbide wafer, and one side of the support block is an arc-shaped surface to fit the circumferential surface of the silicon carbide wafer. The diameter of the silicon carbide ingot is smaller than the diameter of the crystal disk.

[0009] The above-described dual-wire cutting fixture for a 12-inch silicon carbide dicing wafer is described, wherein the silicon carbide wafer is bonded to the end face of the wafer disk by paraffin wax, and the silicon carbide ingot is bonded to the silicon carbide wafer and the end face of the wafer disk by paraffin wax.

[0010] The above-described dual-line cutting fixture for a 12-inch silicon carbide cutting disc includes a cutting wheel comprising a hub, which is an annular component. A rubber ring is bonded to the outer annular surface of the hub, and the outer annular surface of the rubber ring has the aforementioned groove, which is a V-shaped groove. A fixing sleeve is provided on the inner annular surface of the hub, and the fixing sleeve is used to connect with the aforementioned lifting mechanism. The fixed sleeve is provided with multiple first threaded holes for connection with the lifting mechanism.

[0011] As described above, a dual-line cutting fixture for a 12-inch silicon carbide cutting disc is provided with a support surface on the outer circumferential surface of the hub. The thickness of the hub end face from the fixed sleeve to the support surface is less than the thickness of the support surface, and the thickness of the support surface is adapted to the thickness of the rubber ring.

[0012] As described above, a dual-wire cutting fixture for a 12-inch silicon carbide wafer is provided with multiple positioning grooves on the end face of the wafer disk away from the connecting fastener, and the diameters of the silicon carbide wafer and silicon carbide ingot are adapted to the diameters of the corresponding positioning grooves.

[0013] As described above, a dual-wire cutting fixture for a 12-inch silicon carbide wafer is provided with a wafer base at the end of the wafer away from the silicon carbide wafer. The wafer base is an annular component, and a connecting hole is provided at the center of the wafer for connection with the connecting and fixing component. Multiple second threaded holes are provided around the connecting hole. The second threaded holes are located inside the wafer base. The wafer base is provided with positioning holes for positioning the moving mechanism.

[0014] As described above, a dual-wire cutting fixture for a 12-inch silicon carbide cutting disc has a protrusion on the end face of the connecting fastener, which can be inserted into the connecting hole. Multiple stepped through holes are provided around the protrusion, and a V-groove is provided circumferentially on the connecting fastener to connect with the moving mechanism.

[0015] Secondly, the present invention also provides a method for bi-wire cutting of a 12-inch silicon carbide cutting disc, using the aforementioned bi-wire cutting fixture for a 12-inch silicon carbide cutting disc, comprising the following: Connect the fastener to the crystal disk, place the fastener and the crystal disk on the heating table for heating, after the surface of the crystal disk is heated to the set temperature, bond the silicon carbide wafer, after the temperature of the silicon carbide wafer reaches the set temperature, bond the silicon carbide ingot, and wait for the temperature to drop to room temperature. Connect the fastener to the moving mechanism of the cutting equipment; The cutting equipment is connected to two cutting wheels via a lifting mechanism, and the diamond wire is wound around the grooves of the two cutting wheels to form at least two diamond wires. The cutting equipment uses a lifting mechanism to lower the cutting wheel, bringing the diamond wire into contact with the silicon carbide crystal. A moving mechanism moves the silicon carbide crystal back and forth to adjust the contact position between the diamond wire and the silicon carbide crystal. The moving mechanism also causes the silicon carbide crystal to swing left and right. The lifting mechanism lowers the cutting wheel to cut the silicon carbide crystal, resulting in a wafer of the set size.

[0016] As described above, in the dual-wire cutting method for a 12-inch silicon carbide cutting disc, the cutting wheel moves up and down at a speed of 200-800 μm / min, the diamond wire tension is 40-50 N, the silicon carbide disc swings left and right at an angle of ±3°-±6°, and deionized water + silicon carbide cutting fluid is used to cut the silicon carbide disc.

[0017] The beneficial effects of the present invention are as follows: 1) This invention provides a double-wire cutting fixture with at least two wire grooves on the cutting wheel and two diamonds. During the lifting motion of the cutting wheel driven by the lifting mechanism, the two diamond wires can cut the silicon carbide crystal. The silicon carbide cutting sheet can be obtained in one lifting process, without the need to cut the silicon carbide crystal multiple times, which effectively improves the processing efficiency. Moreover, the distance between the diamonds is fixed, which can naturally ensure the thickness of the silicon carbide cutting sheet and prevent uneven thickness. Adding a silicon carbide wafer between the silicon carbide ingot and the disk, with the diameter of the silicon carbide wafer being smaller than that of the silicon carbide ingot, can prevent the silicon carbide ingot from cracking due to the difference in their coefficients of thermal expansion, reduce processing costs, and enable the cutting of silicon carbide ingots of different sizes, especially larger ones such as 12-inch silicon carbide cutting discs.

[0018] 2) In this invention, the bottom of the silicon carbide crystal ingot is supported by a support block. The support block is in contact with the end face of the crystal disk to ensure stable support of the silicon carbide crystal ingot during the cutting process. The silicon carbide wafer is bonded to the end face of the crystal disk with paraffin wax. The silicon carbide crystal ingot is bonded to the end face of the silicon carbide wafer and the crystal disk with paraffin wax. Heating facilitates the melting of the paraffin wax, and the bonding is facilitated after the temperature drops.

[0019] 3) The cutting wheel in this invention is reasonably set. The cutting wheel includes a hub. A rubber ring is bonded to the outer circumferential surface of the hub. Two sets of parallel grooves are set at the rubber ring to ensure that the diamond wires are parallel during the cutting process. The positioning groove on the surface of the crystal disk can realize the positioning of the 12-inch silicon carbide crystal ingot and can collect excess paraffin wax.

[0020] 4) This invention provides a cutting method for silicon carbide cutting discs. The silicon carbide ingot is fixed on a crystal disk, and a silicon carbide wafer is placed between the crystal disk and the silicon carbide ingot. This effectively prevents the silicon carbide ingot from cracking during the heating and bonding process. The silicon carbide ingot is cut by two parallel diamond wires moving synchronously. The efficiency is nearly doubled compared to single-wire cutting. Furthermore, the uniformity of the cutting disc thickness can be adjusted by precisely controlling the spacing between the two wires, resulting in a cutting disc with uniform thickness. This does not damage the quality of the silicon carbide cutting disc and reduces research costs. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0022] Figure 1 This is a front view of a dual-wire cutting fixture for a 12-inch silicon carbide cutting disc according to one or more embodiments of the present invention.

[0023] Figure 2 This is an exploded view of a silicon carbide wafer supported by a wafer in a dual-wire dicing fixture for a 12-inch silicon carbide dicing blade according to one or more embodiments of the present invention.

[0024] Figure 3 This is a side view of a silicon carbide wafer supported by a wafer in a dual-wire dicing fixture for a 12-inch silicon carbide dicing blade according to one or more embodiments of the present invention.

[0025] Figure 4 This is a schematic diagram of the cutting wheel in a dual-wire cutting fixture for a 12-inch silicon carbide cutting disc according to one or more embodiments of the present invention.

[0026] Figure 5 This is a schematic diagram of one side of the wafer in a dual-wire dicing fixture for a 12-inch silicon carbide dicing wafer according to one or more embodiments of the present invention.

[0027] Figure 6 This is a schematic diagram of the other side of the wafer in a dual-wire dicing fixture for a 12-inch silicon carbide dicing wafer according to one or more embodiments of the present invention.

[0028] Figure 7 This is a schematic diagram of the connecting positioning element side in a dual-wire cutting fixture for a 12-inch silicon carbide cutting disc according to one or more embodiments of the present invention.

[0029] Figure 8 This is a schematic diagram of the other side of the connecting positioning element in a dual-wire cutting fixture for a 12-inch silicon carbide cutting disc according to one or more embodiments of the present invention.

[0030] Figure 9 This is the present invention. Figure 4 Enlarged diagram of point A in the middle.

[0031] Figure 10 This is an enlarged cross-sectional view of a dual-wire cutting fixture for a 12-inch silicon carbide cutting disc, according to one or more embodiments of the present invention, showing two wire grooves at the rubber ring.

[0032] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0033] The components include: 1. Cutting wheel; 11. Rubber ring; 111. Wire groove; 12. Hub; 13. First threaded hole; 14. Fixing sleeve; 2. Diamond wire; 3. Resin block; 4. Silicon carbide ingot; 5. Crystal disk; 51. Positioning groove; 52. Connecting hole; 53. Second threaded hole; 54. Positioning hole; 55. Crystal disk base; 6. Silicon carbide wafer; 7. Connecting fastener; 71. Connecting protrusion; 72. V-groove; 73. Stepped through hole; 8. Screw. Detailed Implementation

[0034] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0035] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. As described in the background section, improper silicon carbide wafer cutting methods in the prior art result in low cutting efficiency and easily affect the quality of the obtained silicon carbide wafers, leading to the problem that the whole is not suitable for cutting 12-inch silicon carbide wafers. In order to solve the above technical problems, this invention proposes a dual-wire cutting fixture for 12-inch silicon carbide wafers.

[0036] Example 1 In a typical embodiment of the present invention, reference is made to Figure 1 , Figure 2 and Figure 3 As shown, a dual-wire cutting fixture for a 12-inch silicon carbide cutting disc includes: Two cutting wheels 1 are set at a distance from each other. Each cutting wheel 1 is provided with at least two grooves 111 in the circumferential direction. Two diamond wires 2 are set around the two cutting wheels 1 through the grooves 111 of the two cutting wheels 1 to form two parallel diamond wires 2. The crystal disk 5 is detachably connected to the connecting fastener 7. A silicon carbide wafer 6 is bonded to the end face of the crystal disk 5. A silicon carbide ingot 4 is bonded to the silicon carbide wafer 6 and the end face of the crystal disk. The diameter of the silicon carbide wafer 6 is smaller than the diameter of the silicon carbide ingot 4 to avoid cracking of the silicon carbide ingot 4. The distance between the close surfaces of the two cutting wheels 1 is greater than the diameter of the crystal disk 5. The cutting equipment is connected to both cutting wheels 1 via a lifting mechanism, and the cutting equipment is connected to the connecting fixing part 7 via a moving mechanism.

[0037] Specifically, the bottom of the silicon carbide ingot 4 is supported by a support block. The support block contacts the end face of the wafer 5 and is bonded to the silicon carbide ingot 4. One side of the support block is flat, and the other side is curved to fit the circumferential surface of the silicon carbide ingot 4. The support block is specifically a resin block 3. The resin block 3 is bonded to the 12-inch silicon carbide ingot 4 with adhesive. The silicon carbide wafer 6 is bonded to the wafer 5 with paraffin wax. The 12-inch silicon carbide ingot 4 is bonded to the wafer 6 with paraffin wax and fixed to the wafer 5. The connecting fastener 7 is connected to the wafer 5 with fasteners such as screws 8. The addition of the silicon carbide wafer 6 between the silicon carbide ingot 4 and the wafer 5 can prevent the ingot from cracking due to the difference in their thermal expansion coefficients.

[0038] refer to Figure 4 , Figure 8 and Figure 9 As shown, the cutting wheel 1 includes a hub 12, which is an annular part. A rubber ring 11 is bonded to the outer annular surface of the wheel 12. The rubber ring 11 is wrapped around the hub 12 and bonded together with adhesive. Two rows of grooves 111 are opened on the outer annular surface of the rubber ring 11. The grooves are V-shaped grooves. There is a fixing sleeve 14 in the middle of the hub 12 for connecting with the cutting equipment. Four first threaded holes 13 are opened on the fixing sleeve 14. Fasteners pass through the first threaded holes and are connected to the lifting mechanism.

[0039] Furthermore, a support surface is provided on the outer circumferential surface of the hub 12, and the thickness between the hub end face and the fixed sleeve 14 and the support surface is less than the thickness of the support surface. That is, a step is formed between the support surface and the center section of the hub, and the thickness of the support surface is matched with the thickness of the rubber ring 11.

[0040] It should be noted that the lifting mechanism of the cutting equipment is existing technology, which is an existing lifting cylinder or other type of lifting mechanism.

[0041] refer to Figure 5 As shown, the upper surface of the crystal disk 5 has multiple positioning grooves 51, which can be arranged in multiple rings. The diameter of the positioning grooves is adapted to the diameter of various silicon carbide wafers and silicon carbide ingots, and can be used for positioning silicon carbide wafers and silicon carbide ingots. It can also store excess paraffin wax. Specifically, there can be 5 rings of positioning grooves 51. A crystal disk base 55 is provided at the end of the crystal disk 5 away from the silicon carbide wafer. The crystal disk base 55 is a ring-shaped part, and the diameter of the crystal disk base is smaller than the diameter of the crystal disk 5. (Refer to...) Figure 6 As shown, the center of the crystal disk 5 is provided with a connecting hole 52 for connecting with the connecting fastener 7. Multiple second threaded holes 53 are provided around the connecting hole 52. The second threaded holes 53 are located inside the crystal disk base 55. The end face of the crystal disk base 55 away from the crystal disk 5 is provided with a positioning hole 54 to position the clamp at the moving mechanism.

[0042] It should be explained that the moving mechanism of the cutting equipment is existing technology. The moving mechanism usually includes a linear moving component, which can be a linear slide rail. A processing worktable is provided above the linear slide rail. A swing motor is provided on the worktable. The swing motor is connected to the clamp. The clamp is connected to the connecting fastener 7. The clamp is an existing clamp for cutting machines. The clamp is a hollow cylinder with the same diameter and depth as the connecting protrusion 71. The clamp has three threaded holes at 120° around its perimeter. The connecting fastener 7 is clamped by a top cone.

[0043] refer to Figure 7 and Figure 8 As shown, the connecting fastener 7 is an annular part, and a protrusion 71 is provided on the top of the connecting fastener 7. The protrusion can be inserted into the connecting hole 52 of the connecting fastener 7. The protrusion 71 is an annular block. A V-shaped groove 72 is provided on the circumferential surface of the connecting fastener 7 to connect with the moving mechanism. The connecting fastener 7 has three stepped through holes 73. The stepped through holes 73 are located on the periphery of the protrusion 71. The position of the stepped through holes corresponds one-to-one with the position of the second threaded hole at the crystal disk. This facilitates the fastener, such as the screw 8, to pass through the stepped through holes 73 before connecting to the crystal disk 7.

[0044] When the dual-wire cutting fixture is in operation, the connecting protrusion 71 is inserted into the connecting hole 52, and the connecting fastener 7 and the crystal disk base 55 are tightly fitted together. The connecting fastener 7 is rotated so that the three stepped through holes 73 are aligned with the three second threaded holes 53, and the three screws 8 are screwed in to connect them tightly. The connected fastener 7 and the crystal disk 5 are then placed on a heating table (the heating table includes a platform with a heating resistance wire inside) for heating. The crystal disk 5 has a positioning groove 51, which can store excess paraffin wax. After the surface of the crystal disk 5 is heated to the set temperature, paraffin wax is applied. The paraffin wax is applied evenly, and excess paraffin wax flows into the positioning groove. The silicon carbide wafer 6... Place the silicon carbide wafer 6 in the area coated with paraffin wax, and move it to the center of the crystal disk 5 according to the positioning groove 51. After the silicon carbide wafer 6 has heated up, apply paraffin wax to it. Finally, gently place the silicon carbide ingot 4 of the set size, such as 12 inches, on the silicon carbide wafer 6. Move the 12-inch silicon carbide ingot to the position according to the positioning groove 51 again, so that its edge is flush with the corresponding positioning groove 51. After the temperature drops to room temperature, apply AB glue (two-component mixed hardening glue) to the upper surface and one side surface of the resin block 3, so that the arc-shaped upper surface of the resin block 3 is tightly attached to the side of the silicon carbide ingot, and the side is attached to the crystal disk. Wait for the glue to solidify.

[0045] After solidification, the connecting fastener 7 is placed into the fixture on the cutting equipment, i.e. the cutting machine. The crystal disk has a positioning hole 54, into which the positioning pin on the cutting machine fixture can be inserted to complete the positioning. The fixture is then connected to the moving mechanism.

[0046] The dual-wire cutting fixture provided in this embodiment has a cutting wheel with at least two wire grooves and two diamonds. When the cutting wheel is driven to move up and down by the lifting mechanism, the two diamond wires can cut the silicon carbide crystal. The silicon carbide cutting sheet can be obtained in one lifting process, without the need to cut the silicon carbide crystal multiple times, which effectively improves the processing efficiency. Moreover, the distance between the diamonds is fixed, which can naturally ensure the thickness of the silicon carbide cutting sheet and prevent uneven thickness.

[0047] Example 2 This embodiment provides a dual-wire cutting method for a 12-inch silicon carbide cutting disc, employing a dual-wire cutting fixture for a 12-inch silicon carbide cutting disc as described in Embodiment 1, including the following: Connect the fastener 7 to the crystal disk 5, place the fastener 7 and the crystal disk 5 on the heating table for heating, after the surface of the crystal disk 5 is heated to the set temperature, bond the silicon carbide wafer 6, after the temperature of the silicon carbide wafer 6 reaches the set temperature, bond the silicon carbide ingot 4, and wait for the temperature to drop to room temperature. Connect the fastener 7 to the moving mechanism of the cutting equipment; The cutting equipment is connected to both cutting wheels 1 via a lifting mechanism. The diamond wire 2 is wound around the grooves of the two cutting wheels 1. The diamond wire 2 is wound twice on the grooves 111 of the left and right cutting wheels 1, so that there are two parallel diamond wires 2 in the middle of the two cutting wheels 1. During cutting, the cutting wheel 1 slowly descends, causing the parallel diamond wire 2 to contact the side of the 12-inch silicon carbide ingot. The moving mechanism moves the silicon carbide ingot 4 back and forth, adjusting the contact position between the diamond wire 2 and the silicon carbide ingot 4. The moving mechanism causes the silicon carbide ingot 4 to swing left and right, and the lifting mechanism causes the cutting wheel to descend to cut the silicon carbide ingot 4. Finally, a wafer with a diameter of 12 inches can be cut from the 12-inch silicon carbide ingot 4. This wafer is the first wafer cut after the growth surface (carbon surface) of the 12-inch silicon carbide ingot 4 is ground flat. It can be used as a head wafer to etch and detect the dislocations of the cut 12-inch silicon carbide ingot 4, thereby analyzing the quality of the cut 12-inch silicon carbide ingot 4. The quality indicators of the cut wafer are: Warp ≤ 50 μm, roughness Ra ≤ 0.5 μm, target thickness 600-700 μm, and TTV (total thickness deviation) ≤ 10 μm.

[0048] During the cutting of silicon carbide crystals, the cutting wheel moves up and down at a speed of 200-800 μm / min, the wire tension of the diamond wire is 40-50 N, the left and right swing angle of the silicon carbide crystal is ±3°-±6°, and deionized water + silicon carbide cutting fluid (concentration 5%-10%) is used to cut the silicon carbide crystals.

[0049] During cutting, the first slice is taken from behind the growth surface, i.e. the carbon surface. This slice is then thinned to remove cutting damage and polished to obtain the desired roughness. After being etched with strong alkali, the 12-inch silicon carbide slice can effectively observe dislocations and thus analyze the quality of the 12-inch silicon carbide ingot, reducing research costs.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A double wire sawing tool for a 12 inch silicon carbide cutting blade, characterized by, The application relates to a double-line cutting device for a 12-inch silicon carbide wafer, which comprises the following parts. Two cutting wheels are arranged at a distance, each of the cutting wheels is provided with at least two linear grooves in the circumferential direction, and two diamond wires are arranged around the two cutting wheels through the linear grooves of the two cutting wheels to form two parallel diamond wires. A crystal disc is detachably connected with a connecting fixing part, the end surface of the crystal disc is bonded with a silicon carbide wafer, a silicon carbide ingot is bonded at the end surface of the crystal disc and the silicon carbide wafer, the diameter of the silicon carbide wafer is smaller than that of the silicon carbide ingot to avoid the cracking of the silicon carbide ingot, and the distance between the end surfaces of the two cutting wheels is greater than the diameter of the crystal disc. The cutting device is connected with the two cutting wheels through a lifting mechanism, and the cutting device is connected with the connecting fixing part through a moving mechanism.

2. The double wire saw tooling for a 12 inch silicon carbide cutting blade of claim 1, wherein, The bottom of the silicon carbide ingot is supported by a supporting block, the supporting block is in contact with the end surface of the crystal disc, the supporting block is bonded with the silicon carbide ingot, and one side of the supporting block is an arc surface to adapt to the circumferential surface of the silicon carbide ingot. The diameter of the silicon carbide ingot is smaller than that of the crystal disc.

3. The double wire saw tool for cutting a 12 inch silicon carbide wafer as claimed in claim 1, wherein, The silicon carbide wafer is bonded with the end surface of the crystal disc by paraffin, and the silicon carbide ingot is bonded with the end surface of the crystal disc and the silicon carbide wafer by paraffin.

4. The double wire saw tooling for a 12 inch silicon carbide cutting blade of claim 1, wherein, The cutting wheel comprises a hub, the hub is an annular part, the outer circumferential surface of the hub is bonded with a rubber ring, the outer circumferential surface of the rubber ring is provided with the linear grooves, the linear grooves are V-shaped linear grooves, and the inner circumferential surface of the hub is provided with a fixing sleeve for being connected with the lifting mechanism.

5. The double wire saw tool for cutting a 12 inch silicon carbide wafer as defined in claim 1 wherein, The outer circumferential surface of the hub is provided with a supporting surface, the thickness of the hub from the fixing sleeve to the supporting surface is smaller than that of the supporting surface, and the thickness of the supporting surface is adapted to that of the rubber ring.

6. The double wire saw tool for cutting a 12 inch silicon carbide wafer as defined in claim 1 wherein, The end surface of the crystal disc away from the connecting fixing part is provided with a plurality of positioning grooves, and the diameters of the silicon carbide wafer and the silicon carbide ingot are adapted to those of the corresponding positioning grooves.

7. The double wire saw tool for cutting a 12 inch silicon carbide wafer as defined in claim 1 wherein, The end of the crystal disc away from the silicon carbide wafer is provided with a crystal disc base, the crystal disc base is an annular part, the center of the crystal disc is provided with a connecting hole for being connected with the connecting fixing part, the periphery of the connecting hole is provided with a plurality of second screw holes, the second screw holes are located on the inner side of the crystal disc base, the crystal disc base is provided with a positioning hole for positioning the moving mechanism.

8. The double wire saw apparatus for cutting a 12 inch silicon carbide wafer of claim 7, wherein, The end surface of the connecting fixing part is provided with a convex block which can be clamped into the connecting hole, the periphery of the convex block is provided with a plurality of stepped through holes, and the circumferential surface of the connecting fixing part is provided with a V-shaped groove for being connected with the moving mechanism.

9. A double wire sawing method of a 12 inch silicon carbide cutting blade, characterized by, The application further discloses a double-line cutting device for a 12-inch silicon carbide wafer, which comprises the following steps. The connecting fixing part is connected with the crystal disc, the connecting fixing part and the crystal disc are placed on a heating table for heating, the surface of the crystal disc is heated to a set temperature, the silicon carbide wafer is bonded, the temperature of the silicon carbide wafer is waited to reach the set temperature, the silicon carbide ingot is bonded, and the temperature is waited to reduce to room temperature. The connecting fixing part is connected with the moving mechanism of the cutting device. The cutting device is connected with the two cutting wheels through the lifting mechanism, the diamond wires are arranged around the linear grooves of the two cutting wheels to form at least two diamond wires. The cutting device drives the cutting wheel to descend through the lifting mechanism, so that the diamond wire is in contact with the silicon carbide wafer, the moving mechanism drives the silicon carbide wafer to move forward and backward, the contact position of the diamond wire and the silicon carbide wafer is adjusted, the moving mechanism drives the silicon carbide wafer to swing left and right, the lifting mechanism drives the cutting wheel to descend to cut the silicon carbide wafer, and the wafer with a set size is obtained after cutting.

10. The method of claim 9 wherein the 12 inch silicon carbide cutting blade is a double strand cutting method, wherein, During the cutting of the silicon carbide wafer, the up-down moving speed of the cutting wheel is 200-800 μm / min, the wire tension of the diamond wire is 40-50 N, the left-right swinging angle of the silicon carbide wafer is ±3°-±6°, and deionized water+silicon carbide cutting fluid is used to cut the silicon carbide wafer.

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