Metallic bond thinning grinding wheel for sapphire epitaxial wafer processing and preparation method of metallic bond thinning grinding wheel

Abstract

The metallic bond thinning grinding wheel comprises a base body, a plurality of outer ring grinding wheel teeth are evenly distributed on the outer edge of the end face of the base body at intervals in the circumferential direction, and a plurality of inner ring grinding wheel teeth are evenly distributed on the outer edge of the end face of the base body at intervals in the circumferential direction. According to the grinding wheel tooth, a new formula is adopted, the friction performance is good, under the same machining condition, compared with a traditional grinding wheel, it can be guaranteed that stress borne by a machined part is reduced to the minimum, and therefore the defects of bending and microcracks caused by machining are avoided. The parameters of an existing grinding wheel machining product are as follows: the roughness Rz is less than or equal to 6 microns, the parallelism is less than or equal to 5 microns, the machining beat is 19s, and the service life is 1400P; the product machining parameters of the thinned grinding wheel are as follows: the roughness Rz is less than or equal to 2.6 microns, the parallelism is less than or equal to 2.5 microns, the machining beat is 12s, and the service life is 2800P.

Description

Technical Field

[0001] The invention relates to the technical field of thinning grinding wheels, and in particular to a metal-bonded thinning grinding wheel for processing sapphire epitaxial wafers and a preparation method thereof. Background Art

[0002] Sapphire crystals are extremely hard, and not only have excellent optical, mechanical and good thermal conductivity, but also have good wear resistance and wind erosion resistance, making them an ideal LED substrate material. Sapphire substrates currently have mature production and processing technology, stable quality, and can be used in high-temperature growth processes; in addition, sapphire substrates have high mechanical strength and are easy to handle and clean. Therefore, sapphire is the main substrate material. In recent years, LED technology based on sapphire substrates has developed rapidly, occupying more than 90% of the LED substrate market share; most of the sapphire substrate production capacity is invested in epitaxial wafer production. From the history of LED development, the scale expansion and application of LED backlight and LED lighting have promoted the vigorous development of the LED industry. From the perspective of the industrial chain, the surge in demand for LED backlight and LED lighting has also stimulated the demand of LED packaging plants and their upstream. The strong demand has promoted the development of the LED market and driven the demand for sapphire epitaxial wafers.

[0003] The traditional metal bond thinning grinding wheel consists of a base and grinding wheel teeth. In the prior art, the grinding wheel teeth have defects such as easy chip adhesion, many deep scratches on the workpiece, high wear mark rate (10% to 20%), and other defects in the workpiece surface quality during the grinding process, as well as the difficulty in dressing the grinding wheel.

[0004] Therefore, how to provide a metal bond thinning grinding wheel for sapphire epitaxial wafer processing and a preparation method thereof to solve the problems existing in the prior art is of great significance for its application. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a metal bond thinning grinding wheel for sapphire epitaxial wafer processing and a preparation method thereof, so as to solve the problems in the prior art of unqualified workpiece surface quality such as easy chip sticking, many deep scratches on the workpiece, high wear mark rate (10% to 20%), and difficulty in dressing the grinding wheel during the grinding process.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A metal bond thinning grinding wheel for sapphire epitaxial wafer processing comprises a substrate, a plurality of outer grinding wheel teeth are evenly distributed along the circumferential direction on the outer edge of the end face of the substrate, and a plurality of inner grinding wheel teeth are evenly distributed along the circumferential direction on the outer edge of the end face of the substrate.

[0008] Preferably, a gap is provided between the outer ring grinding wheel teeth and the inner ring grinding wheel teeth, and chip removal holes are provided at intervals in the circumferential direction on the end surface of the base.

[0009] Preferably, the outer ring grinding wheel teeth and the inner ring grinding wheel teeth are in arc shape, and both ends of the outer ring grinding wheel teeth and the inner ring grinding wheel teeth are arc structures.

[0010] Preferably, the outer ring grinding wheel teeth 1 have a height of 12 mm, a width of 7 mm, and a length of 10 mm; the inner ring grinding wheel teeth 4 have a height of 12 mm, a width of 5 mm, and a length of 7 mm; the distance between adjacent grinding wheel teeth in the outer ring grinding wheel teeth 1 is 0.8 to 1 mm; the gap between adjacent grinding wheel teeth in the inner ring grinding wheel teeth 4 is 0.5 to 0.6 mm.

[0011] Preferably, the method for preparing the grinding wheel teeth comprises the following steps:

[0012] Add titanium dioxide whiskers to cyanate monomers, stir at 180°C for 20 minutes, add aluminum phosphate, stir for 2.5 hours, cool naturally, and then grind to obtain a modifier;

[0013] Passing a mixture of diamond, epoxy resin powder, silicon carbide, aluminum oxide, metal cobalt, 4-methylbenzyl alcohol, and a modifier through a 300-mesh sieve to obtain a molding material; hot-pressing the molding material to obtain a hot-pressed green body;

[0014] The grinding wheel teeth are obtained after the hot pressed green body is solidified.

[0015] Preferably, when preparing the modifier, the mass ratio of titanium dioxide whisker, cyanate monomer, and aluminum phosphate is 12:100:19;

[0016] Preferably, in the mixture, the volume percentages of the raw materials are as follows:

[0017] Diamond 18~19%

[0018] Epoxy resin powder 35~40%

[0019] Silicon carbide 6~12%

[0020] Alumina 8~12%

[0021] Cobalt metal 8-15%

[0022] 4-Methylbenzyl alcohol 1~1.2%

[0023] Modifier 6~8%

[0024] Preferably, the particle size of the diamond is 34-40 μm; the diameter of the titanium oxide whisker is 50 nm and the length is 600 nm; the particle size of the aluminum phosphate is 20-28 μm;

[0025] Preferably, the temperature of the hot pressing is 180° C., the pressure is 66 KN, and the time is 15 min; the temperature of the curing is 200° C., and the time is 2 hours.

[0026] A method for preparing a metal bond thinning grinding wheel for sapphire epitaxial wafer processing, characterized in that it comprises the following steps:

[0027] S1, solidifying the hot pressed green body and grinding wheel teeth;

[0028] S2, drilling the end face of the substrate to form a chip removal hole 3;

[0029] S3, bonding the grinding wheel teeth to a substrate by gluing to obtain a thinned grinding wheel;

[0030] The chip removal hole 3 in S2 is perpendicular to the end surface of the base 2 .

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The grinding wheel teeth of the present invention adopt a new formula and have good friction. Under the same processing conditions, compared with the traditional grinding wheel, it can ensure that the stress of the workpiece is reduced to the minimum, thereby avoiding the defects of bending and micro cracks caused by processing. The existing grinding wheel processing product parameters: roughness Rz≤6μm, parallelism≤5μm, processing cycle 19s, life 1400P; the thinning grinding wheel processing product parameters of the present invention: roughness Rz≤2.6μm, parallelism≤2.5μm, processing cycle 12s, life 2800P.

[0033] 2. The grinding wheel teeth of the present invention adopt a new arrangement mode, which has good chip removal. At the same time, chip removal holes are provided, and airflow is generated when the grinding wheel rotates to blow out the waste chips, thereby ensuring smooth chip removal.

[0034] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application so that it can be implemented in accordance with the contents of the specification, and to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following is a detailed description of the preferred embodiments of the present application in conjunction with the accompanying drawings as follows.

[0035] Based on the detailed description of the specific embodiments of the present application in combination with the accompanying drawings below, those skilled in the art will become more aware of the above and other objects, advantages and features of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual scale.

[0037] Figure 1 It is a structural schematic diagram of the present invention;

[0038] Figure 2 It is a schematic diagram of the end face structure of the present invention.

[0039] In the figure: 1. Outer ring grinding wheel teeth; 2. Base body; 3. Chip removal holes; 4. Inner ring grinding wheel teeth. DETAILED DESCRIPTION

[0040] To make the purpose, technical scheme and advantages of the embodiment of the present application clearer, the technical scheme in the embodiment of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the present application. Obviously, the described embodiment is a part of the embodiment of the present application, rather than all of the embodiments. In the following description, specific details such as specific configuration and components are provided only to help fully understand the embodiments of the present application. Therefore, it should be clear to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, for clarity and brevity, the description of known functions and structures is omitted in the embodiment.

[0041] In addition, the present application may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplicity and clarity, and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0042] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist at the same time. The term " / and" in this article describes another type of association object relationship, indicating that there can be two relationships. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " in this article generally indicates that the previous and next associated objects are in an "or" relationship.

[0043] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusions.

[0044] See also Figure 1-2 The present invention provides a technical solution for a metal bond thinning grinding wheel for sapphire epitaxial wafer processing and a preparation method thereof:.

[0045] Embodiment 1

[0046] The method for preparing the grinding wheel teeth comprises the following steps:

[0047] ① Add 1.2 kg of titanium dioxide whiskers to 10 kg of cyanate monomer, then stir at 150 ° C for 30 minutes, then add 1.9 kg of aluminum phosphate, stir for another 2 hours, cool naturally and crush to obtain a modifier;

[0048] ② ball-milling a mixture of diamond, epoxy resin powder, silicon carbide, aluminum oxide, metal cobalt and a modifier (120 rpm / min, 3.5 hours) and then passing through a 300-mesh sieve to obtain a molding material; hot-pressing the molding material to obtain a hot-pressed green body;

[0049] The volume percentage of each raw material in the mixture is as follows:

[0050] Diamond 18%

[0051] Epoxy resin powder 40%

[0052] Silicon carbide 10%

[0053] Alumina 10%

[0054] Cobalt metal 13%

[0055] 4-Methylbenzyl alcohol 1%

[0056] Modifier 8%

[0057] The particle size of diamond is 34-40 μm; the diameter of titanium oxide whisker is 50 nm and the length is 600 nm; the particle size of aluminum phosphate is 20-28 μm;

[0058] The hot pressing temperature was 180°C, the pressure was 66KN, and the time was 15 minutes; the curing temperature was 200°C, and the time was 2 hours.

[0059] ③ Grinding wheel teeth after curing the hot pressed green body;

[0060] The end face machine of the substrate is used to drill a chip removal hole 3; the grinding wheel teeth are bonded to the substrate by gluing to obtain a thinned grinding wheel.

[0061] Processing parameters of thinning grinding wheel: roughness Rz≤2.6μm, parallelism≤2.5μm, processing cycle 12s, life 2800P.

[0062] Embodiment 2:

[0063] The structure of the machined thinning grinding wheel is consistent with that of the first embodiment, and the preparation method comprises the following steps:

[0064] ① ball-milling a mixture of diamond, epoxy resin powder, silicon carbide, aluminum oxide, metal cobalt, and 4-methylbenzyl alcohol (120 rpm / min, 3.5 hours) and then passing through a 300-mesh sieve to obtain a molding material; hot-pressing the molding material to obtain a hot-pressed green body;

[0065] In the mixture, the volume percentage of each raw material is as follows:

[0066] Diamond 23%

[0067] Epoxy resin powder 40%

[0068] Silicon carbide 11%

[0069] Alumina 10%

[0070] Cobalt metal 15%

[0071] 4-Methylbenzyl alcohol 1%

[0072] ② solidifying the hot pressed green body to obtain grinding wheel teeth;

[0073] The grinding wheel teeth are bonded to a substrate by gluing to obtain a thinned grinding wheel, and the wear resistance coefficient at 20° C. is 0.09.

[0074] Processing parameters of thinning grinding wheel: roughness Rz≤4.5μm, parallelism≤3.2μm, processing cycle 16s, life 1900P.

[0075] Existing metal bond grinding wheel parameters: roughness Rz≤6μm, parallelism≤5μm, processing cycle 19s, life 1400P.

[0076] The above description is only the preferred embodiment of the present invention, which does not limit the protection scope of the present invention. For those skilled in the art, the present invention can be modified and varied in various ways. Within the spirit and principle of the present invention, any change, modification, replacement, integration and parameter change of these embodiments by conventional substitution or capable of achieving the same function without departing from the principle and spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A metal bond thinning grinding wheel for sapphire epitaxial wafer processing, characterized in that: It comprises a base (2), wherein a plurality of outer ring grinding wheel teeth (1) are evenly distributed along the circumferential direction on the outer edge of the end surface of the base (2), and a plurality of inner ring grinding wheel teeth (4) are evenly distributed along the circumferential direction on the outer edge of the end surface of the base (2).

2. A metal bond thinning grinding wheel for sapphire epitaxial wafer processing as claimed in claim 1, characterized in that: A gap is provided between the outer ring grinding wheel teeth (1) and the inner ring grinding wheel teeth (4), and chip removal holes (3) are provided at intervals in the circumferential direction on the end surface of the base body (2).

3. A metal bond thinning grinding wheel for sapphire epitaxial wafer processing as claimed in claim 2, characterized in that: The outer ring grinding wheel teeth (1) and the inner ring grinding wheel teeth (4) are in arc shape, and both ends of the outer ring grinding wheel teeth (1) and the inner ring grinding wheel teeth (4) are arc structures.

4. A metal bond thinning grinding wheel for sapphire epitaxial wafer processing as claimed in claim 3, characterized in that: The outer ring grinding wheel teeth (1) have a height of 12 mm, a width of 7 mm, and a length of 10 mm; the inner ring grinding wheel teeth (4) have a height of 12 mm, a width of 5 mm, and a length of 7 mm; the distance between adjacent grinding wheel teeth in the outer ring grinding wheel teeth (1) is 0.8 to 1 mm; and the gap between adjacent grinding wheel teeth in the inner ring grinding wheel teeth (4) is 0.5 to 0.6 mm.

5. A metal bond thinning grinding wheel for sapphire epitaxial wafer processing as claimed in claim 4, characterized in that: The method for preparing the grinding wheel teeth comprises the following steps:

1. Add titanium dioxide whiskers to cyanate monomers, then stir at 180°C for 20 minutes, then add aluminum phosphate, stir for another 2.5 hours, cool naturally, and then crush to obtain a modifier; 2. Passing a mixture of diamond, epoxy resin powder, silicon carbide, aluminum oxide, metal cobalt, 4-methylbenzyl alcohol, and a modifier through a 300-mesh sieve to obtain a molding material; hot-pressing the molding material to obtain a hot-pressed green body; 3. The hot pressed green body is solidified to obtain grinding wheel teeth.

6. The method for preparing grinding wheel teeth according to claim 5, characterized in that: When preparing the modifier, the mass ratio of titanium dioxide whisker, cyanate monomer and aluminum phosphate is 12:100:

19.

7. The method for preparing a grinding wheel tooth according to claim 6, characterized in that: In the mixture, the volume percentage of each raw material is as follows: Diamond 18~19% Epoxy resin powder 35~40% Silicon carbide 6~12% Alumina 8~12% Cobalt metal 8-15% 4-Methylbenzyl alcohol 1~1.2% Modifier 6~8%.

8. The method for preparing grinding wheel teeth according to claim 7, characterized in that: The particle size of the diamond is 34-40 μm; the diameter of the titanium oxide whisker is 50 nm and the length is 600 nm; the particle size of the aluminum phosphate is 20-28 μm.

9. The method for preparing grinding wheel teeth according to claim 8, characterized in that: The temperature of the hot pressing is 180° C., the pressure is 66 KN, and the time is 15 minutes; the temperature of the curing is 200° C., and the time is 2 hours.

10. A method for preparing a metal bond thinning grinding wheel for sapphire epitaxial wafer processing, characterized in that: The following steps are involved: S1, solidifying the hot pressed green body to obtain grinding wheel teeth; S2, drilling the end face of the substrate to form a chip removal hole (3); S3, bonding the grinding wheel teeth to a substrate by gluing to obtain a thinned grinding wheel; The chip removal hole (3) in S2 is perpendicular to the end surface of the base (2).

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