Method for controlling the uniformity of the geometry of a multi-wire cutting blade for crystal cutting

Abstract

The present application relates to a kind of crystal linear cutting piece geometric parameter uniformity method, comprising the following steps: (1) selecting multiple to be cut crystal, to selected crystal is carried out planar grinding and outer circle grinding shaping processing, and is made into standard cylindrical;(2) select multiple resin blocks of set thickness, and be processed into the cylindrical of same diameter with to be cut crystal;(3) select the crystal of shaping completion in step (1) and the resin block of shaping completion in step (2), according to the order of resin block-crystal-resin block-crystal-resin block-crystal-resin block on the adhesive table Crystal and resin block are bonded into a whole;Add set pressure and keep set time;(4) the to be cut crystal of bonding processing completion in step (3) is bonded to the workpiece support plate of multi-wire cutting machine, and pressurization is cooled;(5) the workpiece support plate of bonding good in step (4) is installed to multi-wire cutting machine, and the multi-wire cutting of crystal is carried out.

Description

Technical Field

[0001] This invention belongs to the field of crystal cutting technology, specifically relating to a method for controlling the uniformity of geometric parameters of multi-wire cutting discs in crystal cutting. Background Technology

[0002] In crystal processing, cutting is a crucial step. Currently, multi-wire cutting is the most widely used technology in industrialized crystal processing. Multi-wire cutting is widely adopted due to its high output capacity, low cutting loss, and ability to produce thinner wafers. Especially in cutting high-hardness crystal materials such as single-crystal silicon, silicon carbide, and gallium nitride, multi-wire cutting (crystal) can reduce cutting damage such as cracks and edge chipping on the wafer.

[0003] In multi-wire crystal cutting, there are two main types of cutting wires and cutting processes: one is a metal wire combined with slurry, where the slurry is composed of abrasive particles, solvent, dispersant, and viscosity modifier. During the cutting process, the high-speed moving metal wire drives the slurry through viscosity to achieve abrasive cutting, which is a three-body motion of the metal wire, abrasive particles, and the crystal being cut; the other is diamond wire, where abrasive particles (usually diamond particles) are bonded to the metal wire through physical methods, and cutting is achieved through the direct interaction between the abrasive particles and the crystal, which is a two-body motion.

[0004] However, regardless of the cutting line and cutting process, the cut crystal wafers will always exhibit a certain degree of warp and thickness variation (TTV). This is particularly noticeable for anisotropic crystals or those cut at off-angle.

[0005] The variations in the aforementioned geometric parameters are influenced by a combination of factors, including the state of the cutting fluid (concentration, viscosity, temperature, flow rate, usage cycle, etc.) and cutting wire parameters (tension, speed, oscillation, wire diameter, etc.). Larger geometric parameters increase the difficulty of subsequent processing, reduce the yield, and increase the defect and breakage rates. Especially when multiple crystals are cut at once to increase production capacity, the stress states, defect distributions, and even slight differences in cutting angles among the multiple crystals can interact, resulting in larger geometric parameters for the cutting disc.

[0006] Existing countermeasures typically include using higher concentration slurry, increasing the frequency of slurry replacement, and multi-stage annealing of crystals. However, these measures do not improve the elimination of mutual interference between multiple crystal cutting processes. Summary of the Invention

[0007] The purpose of this invention is to provide a method for controlling the uniformity of geometric parameters of multi-wire cutting discs in crystal cutting. By using resin blocks to bond crystals at intervals, multiple crystals can be cut simultaneously to increase the cutting length, while eliminating the mutual influence between crystals, resulting in cutting discs with low geometric parameters and improving product yield.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method for ensuring the uniformity of geometric parameters of a crystal wire cutter, comprising the following steps:

[0009] (1) Select multiple crystals to be cut, and perform surface grinding and external cylindrical grinding on the selected crystals to form a standard cylindrical shape;

[0010] (2) Select multiple resin blocks of a set thickness and process them into cylindrical shapes with the same diameter as the crystal to be cut;

[0011] (3) Select the crystal that has been shaped in step (1) and the resin block that has been shaped in step (2), and bond the crystal and the resin block together on the gluing table in the order of resin block-crystal-resin block-crystal-resin block-crystal-resin block; apply a set pressure and hold for a set time.

[0012] (4) Bond the crystal to be cut, which has been bonded and processed in step (3), onto the workpiece support plate of the multi-wire cutting machine, apply pressure and wait for cooling;

[0013] (5) Install the workpiece support plate bonded in step (4) onto the multi-wire cutting machine to perform multi-wire cutting of crystal.

[0014] Furthermore, the crystal to be cut in step (1) includes, but is not limited to, crystal materials such as silicon carbide, gallium nitride, aluminum nitride, and gallium oxide.

[0015] Furthermore, the resin block with the set thickness in step (2) has a thickness of 5-20 mm, and the thickness of the resin block is 1 / 3-1 / 4 of the sum of the thicknesses of adjacent crystals.

[0016] Furthermore, in step (3), the adhesive used for bonding is adhesive A, which contains one or more of the following curing agents: aliphatic polyamine, alicyclic polyamine, aromatic polyamine, phenolic resin, and acid anhydride, with the viscosity controlled between 30,000 cps and 60,000 cps. It also contains one or more of the following: polyethylene, polyvinyl chloride, polystyrene, polypropylene, and acrylonitrile-butadiene-styrene resin, with the viscosity controlled greater than 110,000 cps. The set pressure is 50-200 kgf, and the set time is greater than 12 hours.

[0017] Furthermore, in step (4), the adhesive used for bonding is adhesive B, which contains one or more of the following curing agents: aliphatic polyamine, alicyclic polyamine, aromatic polyamine, phenolic resin, and acid anhydride, with the viscosity controlled between 30,000 cps and 60,000 cps. It also contains one or more of the following: polyethylene, polyvinyl chloride, polystyrene, polypropylene, and acrylonitrile-butadiene-styrene resin, with the viscosity controlled to be greater than 110,000 cps. The pressure is applied by covering the crystal 2 with a pressure block 3 of the same size, with a pressure of 50-100 kgf. The pressure block 3 is an arc-shaped metal block.

[0018] Furthermore, the set pressure is 60 kgf, and the set time is 14 hours.

[0019] The technical advantages of this invention are as follows: This invention proposes a method for controlling and reducing the uniformity of geometric parameters in a multi-wire crystal cutting process. By using resin blocks to bond crystals at intervals, it achieves simultaneous cutting of multiple crystals while eliminating mutual interference between them. This reduces the risk of fragmentation and allows for the individual cutting of each crystal, controlling the thickness difference and warping of the cut wafers. This results in wafers with low geometric parameters, facilitating subsequent processing, improving product yield, and enhancing wafer processing quality. Compared to the direct bonding and cutting process of multiple crystals, no additional steps are added. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the resin block crystal bonding structure of the present invention; in the figure, the reference numerals are: 1, resin block; 2, crystal.

[0021] Figure 2 This is a schematic diagram of the structure under pressure after bonding resin blocks and crystals; the attached figures are labeled as follows: 3, pressure block; 1, resin block; 2, crystal; 4, adhesive platform.

[0022] Figure 3 This is a schematic diagram of the workpiece support plate bonding structure; the attached figures are labeled as follows: 2a, bonded crystal, 1, resin block, 5, workpiece support plate.

[0023] Figure 4 A schematic diagram of the structure of the workpiece support plate after bonding and pressurization; 2a, bonded crystal, 1, resin block, 5 workpiece (support) plate, 3, pressure block. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] This invention proposes a method for controlling and reducing the uniformity of geometric parameters of the cut wafer in a multi-wire crystal cutting process. By using resin blocks 1 to bond crystals 2 at intervals, multiple crystals 2 can be cut simultaneously while eliminating mutual influence between crystals 2, achieving the effect of cutting each crystal 2 individually. This controls the thickness difference and bending warp and other geometric parameters of the cut wafers 2, resulting in cut wafers with low geometric parameters. This facilitates subsequent grinding and polishing processes, reduces the difficulty of grinding and polishing, and improves the processing quality of the wafers 2.

[0026] A method for controlling the uniformity of geometric parameters of multi-wire cutters in crystal cutting includes the following steps:

[0027] (1) Select multiple crystals 2 to be cut, and perform planar grinding and outer cylindrical grinding on the selected crystals 2 to form a standard cylindrical shape;

[0028] (2) Select multiple resin blocks 1 with set thicknesses and process them into cylindrical shapes with the same diameter as the crystal 2 to be cut;

[0029] (3) Select the crystal 2 that has been shaped in step (1) and the resin block 1 that has been shaped in step (2), and bond the crystal 2 and the resin block 1 together on the adhesive table 4 in the order of resin block 1-crystal 2-resin block 1-crystal 2-resin block 1-crystal 2-resin block 1; apply a set pressure and hold for a set time.

[0030] (4) Bond the crystal 2 to be cut, which has been bonded and processed in step (3), onto the workpiece support plate 5 of the multi-wire cutting machine, apply pressure and wait for cooling;

[0031] (5) Install the workpiece support plate 5 bonded in step (4) onto the multi-wire cutting machine to perform multi-wire cutting of crystal 2.

[0032] Furthermore, the crystal 2 to be cut in step (1) includes, but is not limited to, crystal materials such as silicon carbide, gallium nitride, aluminum nitride, and gallium oxide.

[0033] Furthermore, in step (2), the thickness of the resin block 1 with the set thickness is 5-20mm, and the thickness of the resin block 1 is 1 / 3-1 / 4 of the sum of the thicknesses of the adjacent crystals 2.

[0034] Furthermore, in step (3), the adhesive used for bonding is adhesive A (further explanation: adhesive A contains one or more of the following curing agents: aliphatic polyamine, alicyclic polyamine, aromatic polyamine, phenolic resin, and acid anhydride, with its viscosity controlled between 30,000 cps and 60,000 cps; it also contains one or more of the following: polyethylene, polyvinyl chloride, polystyrene, polypropylene, and acrylonitrile-butadiene-styrene resin, with its viscosity controlled greater than 110,000 cps), the set pressure is 50-200 kgf, and the set time is greater than 12 hours).

[0035] Furthermore, in step (4), the adhesive used for bonding is adhesive B (further explanation: adhesive B contains one or more of the following curing agents: aliphatic polyamine, alicyclic polyamine, aromatic polyamine, phenolic resin, and acid anhydride, with its viscosity controlled between 30,000 cps and 60,000 cps; it also contains one or more of the following: polyethylene, polyvinyl chloride, polystyrene, polypropylene, and acrylonitrile-butadiene-styrene resin, with its viscosity controlled greater than 110,000 cps). The pressure is applied by covering the crystal 2 with an arc-shaped metal block of the same size (i.e., pressure block 3), and the pressure applied is 50-100 kgf.

[0036] The present invention discloses a method for controlling the uniformity of geometric parameters of a multi-wire cutting wafer. By using a resin block 1 to bond crystals 2 at intervals, multiple crystals 2 can be cut simultaneously while eliminating mutual influence between crystals 2, achieving the effect of cutting each crystal 2 individually. This method controls the thickness difference and bending warp and other geometric parameters of the cut wafers 2, resulting in a cutting wafer with low geometric parameters. This facilitates subsequent processing, improves product yield, and enhances the processing quality of the wafers 2.

[0037] Specifically, a method for controlling the uniformity of geometric parameters of a multi-wire cutter blade in crystal cutting includes the following steps:

[0038] (1) Select multiple crystals 2 to be cut, and perform planar grinding and outer cylindrical grinding on the selected crystals 2 to form a standard cylindrical shape;

[0039] (2) Select multiple resin blocks 1 with set thicknesses and process them into cylindrical shapes with the same diameter as the crystal 2 to be cut;

[0040] (3) Select the crystal 2 that has been shaped in step (1) and the resin block 1 that has been shaped in step (2), and bond the crystal 2 and the resin block 1 together on the gluing table 4 in the order of resin block 1-crystal 2-resin block 1-crystal 2-resin block 1-crystal 2-resin block 1; apply the set pressure for 12 hours.

[0041] (4) Bond the crystal 2 to be cut, which has been bonded and processed in step (3), onto the workpiece support plate 5 of the multi-wire cutting machine, apply pressure and wait for cooling;

[0042] (5) Install the workpiece support plate 5 bonded in step (4) onto the multi-wire cutting machine to perform multi-wire cutting of crystal 2.

[0043] Furthermore, in step (1), the crystal 2 to be cut includes, but is not limited to, crystal materials such as silicon carbide, gallium nitride, aluminum nitride, and gallium oxide;

[0044] Furthermore, in step (2), the resin block 1 with the set thickness has a thickness of 5-20 mm;

[0045] Furthermore, in step (3), the adhesive used for bonding is adhesive A, and the applied pressure is set to 50-200 kgf.

[0046] Furthermore, in step (4), the adhesive used for bonding is adhesive B, and the pressure is applied by an arc-shaped metal block of the same size (see reference). Figure 4 The arc-shaped metal block is a pressure component, namely pressure block 3. Figure 4 The middle cylinder is covered with pressure on the side, and the pressure is 50-100 kgf.

[0047] This invention proposes a method for controlling and reducing the uniformity of geometric parameters of the cut wafers in a multi-wire crystal cutting process. By using resin blocks 1 to bond crystals 2 at intervals, multiple crystals 2 can be cut simultaneously while eliminating mutual interference between them. This reduces the risk of fragmentation and achieves the effect of cutting each crystal 2 individually. It controls the thickness difference and bending / warping geometric parameters of the cut wafers 2, resulting in cut wafers with low geometric parameters. This facilitates subsequent processing, improves product yield, and enhances the processing quality of the wafers 2. Compared to the direct bonding and cutting process of multiple crystals 2, no additional steps are added.

[0048] In summary, the present invention proposes a method for controlling the uniformity of geometric parameters of a multi-wire dicing wafer. By using resin blocks 1 to bond crystals 2 at intervals, multiple crystals 2 can be cut simultaneously while eliminating mutual influence between crystals 2, resulting in dicing wafers with low bending warp and low TTV, which facilitates subsequent processing and improves the processing quality of wafers 2.

[0049] Example

[0050] (1) Three 6-inch conductive silicon carbide ingots were selected and shaped by a surface grinder and a cylindrical grinder to obtain standard cylindrical crystals 2 to be cut. The parallelism of the three crystals 2 all met the requirements (not greater than 0.03 mm). The cutting crystal direction was 4° off from the [11-20] direction in the

[0001] direction, with an angle error of less than 10 arc minutes, and the surface roughness of the crystal 2 to be cut was less than 0.3 micrometers.

[0051] (2) Select 4 resin sheets 1 with thicknesses of 3mm, 3mm, 6mm and 7mm respectively, shape them into a standard 6-inch diameter, with flatness less than 0.03mm and surface roughness less than 0.3 micrometers.

[0052] (3) On the adhesive (platform) 4, in the order of resin block (3mm)-crystal-resin block (6mm)-crystal-resin block (7mm)-crystal-resin block (3mm), use glue A to bond resin block 1 and crystal 2 into a whole cylinder. Apply pressure of 60 kgf and keep on the adhesive platform 4 to heat and bond 4 crystals 2 into a whole in the order and direction of ABBAABBA; and apply pressure of 60 kgf and keep for 14 hours.

[0053] (4) The crystal rod to be cut, which has been bonded and processed in step (3), is bonded to the cutting workpiece (support) plate 5 with B glue, and a pressure of 60 kgf is applied. After the glue has completely cooled, multi-wire cutting can be performed.

[0054] (5) Cutting was performed using a WXSJMW multi-wire cutting machine. The cutting time was 122 hours, the tension was 38N, the linear speed was 26m / s, and the flow rate was 3800kg / m³. 3 .

[0055] (6) A total of 95 cutting discs were obtained, of which 89 were qualified products, and the product yield was 93.68%. The parameters TTV value was 3.762μm-9.217μm, the curvature value was 0.615μm-14.332μm, and the warp value was 4.326μm-16.539μm.

[0056] Therefore, the present invention provides a method for controlling and reducing the uniformity of geometric parameters of the cutting disc in a multi-wire crystal cutting process. By using resin blocks 1 to bond crystals 2 at intervals, multiple crystals 2 can be cut simultaneously to increase the cutting length, while eliminating the mutual influence between crystals 2, resulting in a cutting disc with low geometric parameters and improving product yield.

[0057] In the description of this specification, the references to terms such as "embodiment," "specific embodiment," "some embodiments," etc., refer to specific features, materials, structures, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment. Furthermore, the specific features, materials, structures, or characteristics described may be combined in any suitable manner in one or more embodiments.

[0058] Although embodiments of the invention have been given and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for controlling the uniformity of geometric parameters of a multi-wire dicing blade in crystal cutting, characterized in that, Includes the following steps: (1) Select multiple crystals (2), and perform planar grinding and outer cylindrical grinding on the selected crystals (2) to form a standard cylindrical shape; (2) Select multiple resin blocks (1) with a set thickness and process them into cylindrical shapes with the same diameter as the crystal (2) to be cut; (3) Select the crystal (2) shaped in step (1) and the resin block (1) shaped in step (2), and bond the crystal (2) and the resin block (1) together on the gluing table (4) in the order of resin block (1)-crystal (2)-resin block (1)-crystal (2)-resin block (1)-crystal (2)-resin block (1)-crystal (2)-resin block (1); apply a set pressure and hold for a set time; (4) Bond the crystal (2) to be cut after the bonding process in step (3) to the workpiece support plate (5) of the multi-wire cutting machine, apply pressure and wait for cooling; (5) Install the workpiece support plate (5) bonded in step (4) onto the multi-wire cutting machine to perform multi-wire cutting of crystal (2); In step (3), the adhesive used for bonding is adhesive A. Adhesive A contains one or more of the following curing agents: aliphatic polyamine, alicyclic polyamine, aromatic polyamine, phenolic resin, and acid anhydride. The viscosity is controlled between 30,000 cps and 60,000 cps. It also contains one or more of the following: polyethylene, polyvinyl chloride, polystyrene, polypropylene, and acrylonitrile-butadiene-styrene resin. The viscosity is controlled to be greater than 110,000 cps. The set pressure is 50-200 kgf, and the set time is greater than 12 hours. In step (4), the adhesive used for bonding is adhesive B. Adhesive B contains one or more of the following curing agents: aliphatic polyamine, alicyclic polyamine, aromatic polyamine, phenolic resin, and acid anhydride. The viscosity is controlled between 30,000 cps and 60,000 cps. It also contains one or more of the following: polyethylene, polyvinyl chloride, polystyrene, polypropylene, and acrylonitrile-butadiene-styrene resin. The viscosity is controlled to be greater than 110,000 cps. The pressure is applied by covering the crystal (2) with a pressure block (3) of the same size. The pressure is 50-100 kgf. The pressure block (3) is an arc-shaped metal block.

2. The method for controlling the uniformity of geometric parameters of a multi-wire cutting disc in crystal cutting according to claim 1, characterized in that: The crystal (2) mentioned in step (1) includes, but is not limited to, crystal materials such as silicon carbide, gallium nitride, aluminum nitride, and gallium oxide.

3. The method for controlling the uniformity of geometric parameters of a multi-wire cutting disc in crystal cutting according to claim 1, characterized in that: The resin block (1) with a set thickness in step (2) has a thickness of 5-20 mm, and the thickness of the resin block (1) is 1 / 3-1 / 4 of the sum of the thicknesses of the adjacent crystals (2).

4. The method for controlling the geometric parameter uniformity of a multi-wire cutting disc in crystal cutting according to claim 1, characterized in that, The set pressure is 60 kgf, and the set time is 14 hours.

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