A suspension grinding aid, its preparation method and application

Abstract

The present application relates to a kind of suspension grinding aids and its preparation method and application.The suspension grinding aid is composed of the following mass fraction of components: abrasive 10-50%, suspension dispersing agent 0.01-15%, organic base 1-20%, lubricant 1-30%, surface wetting agent 0.1-10%, and the balance is water.The suspension grinding aid is used for hard and brittle material thinning processing, which has high efficiency, less damage to hard and brittle material, can be reused multiple times, has long service life, and has wide application field.

Description

Technical Field

[0001] This invention relates to the field of grinding technology for hard and brittle materials, and more specifically, to a suspending grinding aid, its preparation method, and its application. Background Technology

[0002] Hard and brittle materials are characterized by high hardness and brittleness, with their elastic limit and strength being very close; they are often non-metallic materials. The physical and mechanical properties of hard and brittle materials differ significantly from those of metallic materials, making them prone to surface cracking and damage during processing.

[0003] Sapphire is a common hard and brittle material, a single crystal of aluminum oxide, possessing excellent thermal, optical, and dielectric properties, as well as superior mechanical properties, good chemical and thermal stability, and radiation resistance. It is a high-performance, multifunctional crystal widely used in semiconductor epitaxial substrates, aerospace windows, optical lenses, medical applications, watch surfaces, mobile phone home buttons, displays, and cameras. Currently, in sapphire thinning processes, cast iron grinding discs are commonly used in conjunction with grinding aids for double-sided thinning. There are two types of grinding aids: oil-based and water-based. Oil-based aids have low thinning efficiency, poor abrasive suspension and dispersion, easily scratch the material surface, are difficult to clean, and pose a significant environmental hazard. Water-based aids have higher efficiency but poor lubrication, easily scratching the material surface and even causing cracking. Furthermore, after shutdown, the abrasive tends to settle and clump, resulting in a short service life. A Chinese patent entitled "Sapphire Grinding Fluid, Sapphire Grinding Fluid Preparation Process, and Sapphire Grinding Fluid Usage Method" provides a sapphire grinding fluid, but this patent does not address the issue of material scratching.

[0004] Therefore, it is necessary to solve the problems of low processing efficiency, easy scratching of materials, and short service life of existing grinding aids. Summary of the Invention

[0005] The primary objective of this invention is to overcome the problems of low processing efficiency, easy material scratching, and short service life of existing grinding aids, and to provide a suspension grinding aid. This suspension grinding aid is highly efficient in the thinning process of hard and brittle materials, causes less damage to hard and brittle materials, can be reused multiple times, has a long service life, and has a wide range of applications.

[0006] A further object of the present invention is to provide a method for preparing the above-mentioned suspending grinding aid.

[0007] A further object of the present invention is to provide the application of the above-mentioned suspending grinding aid in the thinning process of hard and brittle materials.

[0008] The above-mentioned objective of the present invention is achieved through the following technical solution:

[0009] A suspending grinding aid, comprising the following components by mass fraction:

[0010]

[0011]

[0012] The abrasive has an average particle size of 25–100 μm; the suspending dispersant is a polymer with a viscosity of 3000–8000 cP.

[0013] Through extensive research, the inventors of this invention have discovered that in grinding aids, if the particle size of the abrasive used is too large, although it has high processing efficiency for hard and brittle materials, the grinding aid is prone to scratching these materials. Conversely, if the particle size of the abrasive used is too small or the viscosity of the suspending dispersant is too low, the suspension effect is poor, the processing efficiency is low, and the service life is short. If the viscosity of the suspending dispersant is too high, it will result in poor flowability of the grinding aid, leading to low processing efficiency, excessive damage to hard and brittle materials, and a short service life.

[0014] This invention utilizes abrasives with a specific average particle size (25–100 μm) and a polymer suspending agent with a specific viscosity (3000–8000 cP), along with organic alkali, lubricant, surface wetting agent, and water, to obtain a suspension grinding aid with high processing efficiency, minimal material scratching, and long service life. The reasons are as follows: First, the combination of abrasives with a specific average particle size and polymer suspending agent with a specific viscosity results in a long suspension time and good fluidity of the suspension grinding aid. Furthermore, based on good fluidity, the abrasives with the specific average particle size are well-compatible with the organic alkali, lubricant, and surface wetting agent, exhibiting a synergistic effect. This results in high processing efficiency for hard and brittle materials, good surface quality of the processed materials, and the suspension grinding aid can be reused multiple times, extending its service life.

[0015] The suspension grinding aid of the present invention is highly efficient in the thinning process of hard and brittle materials, causes little damage to hard and brittle materials, can be reused multiple times, has a long service life, and has a wide range of applications.

[0016] Preferably, it consists of components with the following mass fractions:

[0017]

[0018] Preferably, the average particle size of the abrasive is 25–65 μm.

[0019] Preferably, the abrasive is at least one of boron carbide, silicon carbide, aluminum oxide, or diamond.

[0020] More preferably, the abrasive is silicon carbide.

[0021] Preferably, the viscosity of the suspending dispersant is 3000-4000 cP.

[0022] Preferably, the suspending dispersant is at least one of polyacrylic acid and its salts, polymaleic acid and its salts, polyurethane, polyamide or polyurea.

[0023] More preferably, the suspending dispersant is polyurethane.

[0024] Preferably, the organic base is at least one selected from monoethanolamine, diethanolamine, triethanolamine, triethylamine, or hydroxyethylethylenediamine.

[0025] More preferably, the organic base is at least one of monoethanolamine or hydroxyethyl ethylenediamine.

[0026] More preferably, the organic base is monoethanolamine.

[0027] Using monoethanolamine as the organic base results in less damage to hard and brittle materials after thinning, leading to a higher pass rate.

[0028] Preferably, the lubricant is at least one selected from glycerin, propylene glycol, diethylene glycol, triethylene glycol, ethylene glycol, polyethylene glycol, or polypropylene glycol.

[0029] More preferably, the lubricant is glycerin.

[0030] Glycerin is selected as the lubricant, resulting in a suspended grinding aid used in the thinning process of hard and brittle materials. This causes less damage to the hard and brittle materials and results in a higher yield of finished products.

[0031] Preferably, the surface wetting agent is at least one of fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether phosphate, or alkynyldiol.

[0032] More preferably, the surface wetting agent is fatty alcohol polyoxyethylene ether.

[0033] When the surface wetting agent is fatty alcohol polyoxyethylene ether, the resulting suspending grinding aid is used in the thinning process of hard and brittle materials, causing less damage to the hard and brittle materials and resulting in a higher pass rate for the processed hard and brittle material products.

[0034] This invention also protects a method for preparing the above-mentioned suspending grinding aid, comprising the following steps:

[0035] The suspending dispersant and lubricant are mixed, dissolved in water, and then an organic alkali, a surface wetting agent, and abrasive are added and mixed evenly to obtain the suspending grinding aid.

[0036] The application of the above-mentioned suspending grinding aid in the thinning process of hard and brittle materials is also within the scope of protection of this invention.

[0037] Preferably, the hard and brittle material is sapphire.

[0038] Compared with the prior art, the beneficial effects of the present invention are:

[0039] This invention, by selecting abrasives with a specific average particle size and combining them with polymer suspending dispersants of a specific viscosity, and then adding organic alkalis, lubricants, surface wetting agents and water, can obtain a suspension grinding aid with high processing efficiency, minimal material scratching, and long service life. In other words, the suspension grinding aid of this invention is highly efficient for thinning processing of hard and brittle materials, causes minimal damage to hard and brittle materials, can be reused multiple times, has a long service life, and has a wide range of applications. Detailed Implementation

[0040] To more clearly and completely describe the technical solution of the present invention, the present invention is further described in detail below through specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. Various changes can be made within the scope of the claims of the present invention. Unless otherwise specified, other raw materials and reagents of the present invention are all raw materials and reagents that can be obtained from conventional markets and other commercial channels.

[0041] The reagents used in the various embodiments and comparative examples of this invention are described below:

[0042] Abrasive #1: Composed of boron carbide, with an average particle size of 65μm;

[0043] Abrasive #2: Composed of boron carbide, with an average particle size of 25μm;

[0044] Abrasive #3: Composed of silicon carbide, with an average particle size of 65μm;

[0045] Abrasive #4: Composed of boron carbide, with an average particle size of 0.5 μm;

[0046] Abrasive #5: Composed of boron carbide, with an average particle size of 120μm;

[0047] Suspension dispersant 1#: Composition is polyurethane, grade RM-12W, viscosity is 4000 cP;

[0048] Suspension dispersant #2: Composition is polyurethane, grade RM-8W, viscosity is 3000 cP;

[0049] Suspension dispersant #3: Composed of polyurethane, grade 3030, viscosity 20000 cP.

[0050] Organic base 1#: Monoethanolamine, purity 99%;

[0051] Organic base #2: Hydroxyethyl ethylenediamine, purity 99%;

[0052] Organic base #3: Triethylamine, purity 99%;

[0053] Lubricant #1: Glycerin, purity 99.5%;

[0054] Lubricant #2: Diethylene glycol, purity 99%;

[0055] Surface wetting agent 1#: fatty alcohol polyoxyethylene ether, purity 99%;

[0056] Surface wetting agent #2: acetylenic diol, purity 99%;

[0057] Water: Pure water.

[0058] The preparation methods of the suspension grinding aids in each embodiment and comparative example are as follows: weigh each component according to the formula, mix the suspension dispersant and lubricant, dissolve in water, then add organic alkali, surface wetting agent and abrasive, mix well, and the suspension grinding aid is obtained.

[0059] Examples 1-12

[0060] Examples 1-12 provide a series of suspending grinding aids, and the formulations of each example are shown in Table 1.

[0061] Table 1. Formulations (mass fraction %) of the suspending grinding aids in Examples 1-12

[0062]

[0063] Comparative Examples 1-5

[0064] Comparative Examples 1–5 provide a series of suspending grinding aids, and the formulations of each comparative example are shown in Table 2.

[0065] Table 2. Formulations of suspension grinding aids for Comparative Examples 1–5 (mass fraction %)

[0066]

[0067]

[0068] Performance testing

[0069] The suspending grinding aids from Examples 1-12 and Comparative Examples 1-5 were used for sapphire substrate thinning tests. The sapphire substrate samples were thinned on a Bohongyuan 16B double-sided thinning machine. The parameters for the thinning test were as follows: sapphire substrate sample size: 4 inches; pressure: 150 kg; grinding disc speed: 25 rpm; suspending grinding aid flow rate: 100 mL / min; number of thinned wafers: 40 wafers / disc. The thinning efficiency (average thickness reduced per minute; a higher value indicates higher efficiency; a lower value indicates lower efficiency), the number of thinning discs (the more discs thinned by a single addition of suspending grinding aid to the double-sided thinning machine, the longer the service life of the suspending grinding aid, and vice versa), the number of damaged wafers (the sum of the number of damaged sapphire substrate wafers per disc), and the pass rate (number of damaged wafers / total number of thinned wafers, total number of thinned wafers = 40 * number of thinning discs) were recorded. The results are shown in Table 3.

[0070] Table 3 Test results of the suspension grinding aids in the examples and comparative examples.

[0071] Thinning efficiency μm / min Number of thinner trays / tray Number of damaged pieces / piece Pass rate / % Example 1 1.8116 13 5 99.0％ Example 2 1.6015 13 0 100％ Example 3 2.4000 13 30 94.2％ Example 4 1.6875 13 4 99.0％ Example 5 2.0156 13 21 96.0％ Example 6 1.8628 13 10 98.1％ Example 7 2.0983 13 10 98.1％ Example 8 2.1338 13 14 97.3％ Example 9 2.0650 13 16 96.9％ Example 10 2.0965 13 10 98.1％ Example 11 1.6512 13 12 97.7％ Example 12 2.6500 13 10 98.1％ Comparative Example 1 1.4105 11 30 90.9％ Comparative Example 2 1.3416 10 21 95.5％ Comparative Example 3 0.3770 5 0 100％ Comparative Example 4 2.7052 13 52 90.0％ Comparative Example 5 1.4285 11 23 94.8％

[0072] As can be seen from Table 3:

[0073] The thinning efficiency of the suspension grinding aids in Examples 1 to 12 is above 1.6 μm / min, the number of thinning discs can reach 13, and the pass rate can reach above 94.2%. This shows that the suspension grinding aid of the present invention has high efficiency in thinning processing of hard and brittle materials, causes less damage to hard and brittle materials, can be reused multiple times, and has a long service life.

[0074] As can be seen from Examples 1 and 7-8, when monoethanolamine or hydroxyethyl ethylenediamine is selected as the organic base (Example 1 or Example 7), the suspending grinding aid is used for the thinning process of hard and brittle materials, resulting in less damage to the hard and brittle materials and thus a higher yield of sapphire substrate products. This may be because the presence of hydroxyl groups in the organic base makes the compatibility of each component (including abrasive, suspending dispersant, organic base, lubricant, and surface wetting agent) better, thereby further reducing the damage of abrasive to hard and brittle materials.

[0075] As can be seen from Examples 1 and 9, when glycerin (Example 1) is selected as the lubricant, the suspension grinding aid is used for the thinning process of hard and brittle materials, causing less damage to the hard and brittle materials and resulting in a higher yield of sapphire substrate products.

[0076] As can be seen from Examples 1 and 10, when fatty alcohol polyoxyethylene ether (Example 1) is selected as the surface wetting agent, the suspension grinding aid is used for the thinning process of hard and brittle materials, which causes less damage to the hard and brittle materials and results in a higher pass rate for sapphire substrate products.

[0077] As can be seen from Examples 1 and 11, when the average particle size of the abrasive is within a suitable range (25-65 μm), the suspending grinding aid is used for the thinning of hard and brittle materials, resulting in high processing efficiency, less damage to the hard and brittle materials, and can be reused multiple times with a long service life.

[0078] As can be seen from Examples 1 and 12, when silicon carbide is used as the abrasive (Example 12), the processing efficiency of the suspension grinding aid is higher.

[0079] In Comparative Example 1, the viscosity of the added suspending dispersant was too high, resulting in a low efficiency of the resulting grinding aid in the thinning process of hard and brittle materials. It caused significant damage to the materials, resulting in fewer discs being thinned and a shorter service life. In Comparative Example 2, no suspending dispersant was added, and the resulting grinding aid also had low efficiency in the thinning process of hard and brittle materials, with fewer discs being thinned and a shorter service life. In Comparative Example 3, the average particle size of the added abrasive was too small, resulting in very low thinning efficiency and a short service life for the grinding aid. In Comparative Example 4, the particle size of the added abrasive was too large, causing significant damage to the hard and brittle materials during the thinning process, leading to a very low yield of the hard and brittle material products. In Comparative Example 5, no organic alkali was added, and the resulting grinding aid had low efficiency in the thinning process of hard and brittle materials, with fewer discs being thinned and a shorter service life.

[0080] In summary, by selecting abrasives with a specific average particle size and combining them with polymer suspending dispersants of a specific viscosity, and then adding organic alkalis, lubricants, surface wetting agents, and water, this invention can obtain a suspension grinding aid with high processing efficiency, minimal material scratching, and long service life. In other words, the suspension grinding aid of this invention is highly efficient for thinning hard and brittle materials, causes minimal damage to hard and brittle materials, can be reused multiple times, has a long service life, and has a wide range of applications.

[0081] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A suspending grinding aid, characterized in that, It consists of components with the following mass fractions: Abrasive 25%, 5% suspension dispersant Triethylamine 10%, 15% lubricant 5% surface wetting agent The remainder is water; The abrasive is boron carbide with an average particle size of 65 μm; the suspending and dispersing agent is polyurethane with a viscosity of 4000 cP. The lubricant is glycerin, and the surface wetting agent is fatty alcohol polyoxyethylene.

2. The method for preparing the suspending grinding aid according to claim 1, characterized in that, Includes the following steps: The suspending dispersant and lubricant are mixed, dissolved in water, and then triethylamine, surface wetting agent and abrasive are added and mixed evenly to obtain the suspending grinding aid.

3. The application of the suspending grinding aid as described in claim 1 in the thinning process of hard and brittle materials.

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