Diamond wire cutting fluid for alleviating color difference in cutting of large-size silicon wafers, and preparation method therefor

Abstract

A diamond wire cutting fluid for alleviating color difference in the cutting of large-size silicon wafers, and a preparation method therefor, relating to the technical field of diamond wire cutting. The diamond wire cutting fluid comprises the following components in percentage by mass: 18-22% of a dispersing agent, 20-26% of a wetting agent, 2-5% of a thickening agent, and the balance being ultrapure water. The thickening agent is one or more of Arquad T-50, Aromox 14D-W970, and Aromox MCD-W. The provided diamond wire cutting fluid can effectively reduce silicon powder content in a cutting process, fills gaps between diamond particles on a diamond wire, prevents silicon powder from being adsorbed to and wrapping the surface of the diamond wire, improves the cutting capability of the diamond wire, can substantially solve the problems of wire breakage, color difference, wire marks, TTV, etc. in a silicon wafer thinning production process using a smaller diamond wire, and greatly effectively reduces the proportion of defective products in the silicon wafer cutting process.

Description

Diamond wire cutting fluid for improving color difference in cutting large-size silicon wafers and preparation method thereof Technical Field

[0001] The present invention belongs to the technical field of diamond wire cutting, and in particular relates to a diamond wire cutting liquid for improving chromatic aberration in cutting large-size silicon wafers and a preparation method thereof. Background Art

[0002] At present, with the acceleration of the process of silicon wafer thinning and fine-line processing, silicon wafer yield has become one of the key assessment targets of photovoltaic companies. However, in the process of pursuing silicon wafer thinning, fine-line processing and yield, increasingly prominent problems such as color difference, edge collapse, line marks and TTV have become a bottleneck restricting the development of large-size silicon wafers.

[0003] The industry currently addresses issues such as color difference and line marks, which are common in silicon wafer production, by focusing on the slicing process. This includes increasing the wire consumption of new diamond wire for single-cutting, or adjusting the wire feed and return rates and the circulation process during the cutting process. Chinese patent application CN106939182A discloses an aqueous diamond wire silicon wafer cutting fluid and a method for producing the fluid. The fluid comprises a polyether, a dispersing and wetting agent, a penetrant, an anti-rust and anti-bacterial agent, an organic base, and a defoamer. The aqueous diamond wire silicon wafer cutting fluid comprises, by weight, 10% to 35% polyether, 12% to 25% dispersing and wetting agent, 3% to 5% penetrant, 0.1% to 0.2% anti-rust and anti-bacterial agent, and 1% to 4% defoamer. Chinese patent application CN105062622A discloses a cutting fluid for wire saw cutting. The cutting fluid for wire saw cutting is composed of an extreme pressure lubricant, a coolant, and a basic dye. The basic dye includes methyl violet, ammonium oxalate crystal violet, and acetic acid carmine. The extreme pressure lubricant accounts for 50%-51% of the total weight of the cutting fluid for wire saw cutting, the coolant accounts for 47%-49% of the total weight of the cutting fluid for wire saw cutting, and the basic dye accounts for 1%-2% of the total weight of the cutting fluid for wire saw cutting.

[0004] Existing diamond wire cutting fluids have only improved their dispersing, wetting, and lubricating properties, limited to conventional polyether and alkyl alcohol ether wetting agents with dispersing and lubricating properties. While these have somewhat alleviated the difficulties in dispersing silicon powder and wetting the cutting seam during diamond wire cutting, they have not significantly improved issues such as color shading, edge chipping, line marks, and TTV. Consequently, silicon wafer yields are struggling to meet production targets. Therefore, there is an urgent need to develop a diamond wire cutting fluid that can significantly reduce the incidence of defective products such as wire breakage, color shading, line marks, and TTV.

[0005] Summary of the Invention

[0006] In response to the shortcomings of the prior art, the present invention aims to provide a diamond wire cutting fluid and its preparation method for improving color difference during the cutting of large-sized silicon wafers. The diamond wire cutting fluid provided by the present invention can effectively reduce the silicon powder content during the cutting process, fill the gaps between diamond particles on the diamond wire, prevent silicon powder from being adsorbed and coated on the surface of the diamond wire, and improve the cutting ability of the diamond wire. It can substantially solve problems such as wire breakage, color difference, line marks, and TTV that exist in the production process of thinning and slicing, and significantly and effectively reduce the proportion of defective products produced during the silicon wafer cutting process.

[0007] The technical solution of the present invention is:

[0008] A diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers comprises the following components and their mass percentages: 18-22% of a dispersant, 20-26% of a wetting agent, 2-5% of a thickener, and the balance being ultrapure water.

[0009] Furthermore, the diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers comprises the following components and their mass percentages: 22% dispersant, 22.5% wetting agent, 2.5% thickener, and 53% ultrapure water.

[0010] Furthermore, in the diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers, the dispersant is one or more of polyethylene oxide polypropylene oxide block polyether with a single end capping of C4 alcohol, polyethylene oxide polypropylene oxide block polyether with a single end capping of C6 alcohol, and polyethylene oxide polypropylene oxide block polyether with a single end capping of C8 alcohol.

[0011] Furthermore, the C4 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether has a structure shown in formula (I):

[0012] Wherein, R1 is one of n-butanol and isobutanol, 5≤m≤20, 5≤n≤20, 10≤m+n≤40, and m and n are both integers.

[0013] Furthermore, the C6 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether has a structure shown in formula (II):

[0014] Wherein, 5≤p≤20, 5≤q≤20, 10≤p+q≤40, p and q are both integers, and R2 is one of the following three alcohols:

[0015] Furthermore, the C8 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether has a structure shown in formula (III):

[0016] Wherein, 5≤x≤20, 5≤y≤20, 10≤x+y≤40, x and y are both integers, and R3 is one of the following two alcohols:

[0017] Furthermore, the dispersant is composed of C4 alcohol single-terminated polyethylene oxide polypropylene oxide block polyether and C6 alcohol single-terminated polyethylene oxide polypropylene oxide block polyether in a mass ratio of 4-5:6-8.

[0018] Furthermore, the dispersant is composed of C4 alcohol single-terminated polyethylene oxide polypropylene oxide block polyether and C6 alcohol single-terminated polyethylene oxide polypropylene oxide block polyether in a mass ratio of 5:6.

[0019] Furthermore, the wetting agent is isomeric C12-C14 alcohol polyoxyethylene ether.

[0020] Furthermore, the isomeric C12-C14 alcohol polyoxyethylene ether has a structure shown in formula (IV):

[0021] Wherein, R4 is an isomeric C12-C14 fatty mixed alcohol, 3≤a≤6, and a is an integer.

[0022] Furthermore, the thickener is one or more of Arquad T-50 (AkzoNobel), Aromox 14D-W970 (AkzoNobel), and Aromox MCD-W (AkzoNobel).

[0023] Furthermore, the thickener is composed of Arquad T-50 and Aromox 14D-W970 in a mass ratio of 1-3:3-5.

[0024] Furthermore, the thickener is composed of Arquad T-50 and Aromox 14D-W970 in a mass ratio of 2:3.

[0025] Another object of the present invention is to provide a method for preparing the diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers, comprising the following steps:

[0026] Add ultrapure water and thickener to the reactor in sequence, stir at a stirring speed of 1000-1500 rpm for 30-60 minutes, and after the solution is uniform and stable, add dispersant and wetting agent in sequence, stir for 2-4 hours, and age for 1 hour to obtain the product.

[0027] Usage: dilute the diamond wire cutting fluid for improving the color difference of large-size silicon wafer cutting with ultrapure water in the cutting machine cylinder to a concentration of 0.25% to 1%. After mixing, start cutting.

[0028] The existing technologies all consider the dispersion and wetting of silicon powder. Although the silicon powder can be well dispersed in the cylinder during the cutting process, the concentration of silicon powder becomes higher and higher as the cutting process proceeds. When the thickness of the processed silicon wafer becomes thinner and the size of the silicon wafer increases, the silicon powder content will increase sharply. The increased specific surface area of ​​the silicon powder will also increase the consumption of dispersants and wetting agents, resulting in insufficient wetting and dispersion of the silicon powder during the cutting process.

[0029] The thickener of the present invention is one or more of Arquad T-50 (AkzoNobel), Aromox 14D-W970 (AkzoNobel), and Aromox MCD-W (AkzoNobel). The thickener of the present invention can flocculate and agglomerate the silicon powder in the cylinder during the cutting process, so that the silicon powder particle size becomes larger and settles at the bottom of the cylinder, thereby reducing the content of dispersed silicon powder in the aqueous solution. The cutting circulating water supply pump draws water from the upper middle part of the cylinder and transports it to the aqueous solution for cutting spraying, where the silicon powder content is greatly reduced, effectively avoiding the silicon powder from secondary wrapping of the diamond wire, adhering to the silicon wafer, the pulley, and the inner wall of the workbench, maintaining the cutting ability of the diamond wire, reducing the probability of wire net breakage and retracting wire breakage, reducing the cutting color difference problem on the silicon wafer surface caused by insufficient diamond wire cutting ability, and improving the unfavorable situation in which the silicon powder concentration in the cutting process becomes higher and higher as the cutting process proceeds. In particular, it has a strong cutting effect for cutting long silicon rods or large-sized silicon rods in a small cylinder and a cutting environment with a high silicon powder concentration in the cylinder, and can substantially solve the problems of wire breakage, color difference, line marks, TTV, etc. in the production process of thinning and thinning, and greatly and effectively reduce the proportion of defective products produced during the silicon wafer cutting process.

[0030] The thickener of the present invention can reduce the consumption of dispersants and wetting agents. Since the thickener in the cylinder has a large molecular weight and a slow migration and adsorption speed on the surface of the silicon powder, it will not immediately take effect on the fresh interface generated by the new silicon powder. It can keep the wetting agent and dispersant adsorbed on the surface of the silicon powder during the cutting process, achieving the effect of wetting and dispersing at the cutting interface without causing silicon powder agglomeration. When these silicon powder aqueous solutions flow back into the cylinder, the thickener will replace the wetting agent and dispersant adsorbed on the surface of the silicon powder, causing the silicon powder to agglomerate together. Therefore, the dispersant and wetting agent that have been absorbed and consumed during the cutting process can be released, which can effectively reduce the consumption of cutting fluid components during the cutting process and reduce the amount of dispersant and wetting agent used.

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

[0032] (1) The introduction of a specific thickener into the diamond wire cutting fluid formula of the present invention can not only enhance the efficiency of the use of dispersants and wetting agents, but also reduce the amount of dispersants and wetting agents used, thereby improving the overall cost-effectiveness;

[0033] (2) The diamond wire cutting fluid provided by the present invention can effectively reduce the silicon powder content in the cutting process, fill the gaps between the diamond particles on the diamond wire, avoid the silicon powder adsorbed and wrapped on the surface of the diamond wire, improve the cutting ability of the diamond wire, and can substantially solve the problems of wire breakage, color difference, line marks, TTV, etc. in the production process of thinning and slicing, and greatly and effectively reduce the proportion of defective products produced during the silicon wafer cutting process. DETAILED DESCRIPTION

[0034] The present invention is further illustrated below by describing specific implementation methods, but this is not intended to limit the present invention. Those skilled in the art can make various modifications or improvements based on the basic ideas of the present invention, but as long as they do not deviate from the basic ideas of the present invention, they are all within the scope of the present invention.

[0035] Example 1: A diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers

[0036] The diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers comprises the following components and their mass percentages: 20% dispersant, 20% wetting agent, 2.5% thickener, and 57.5% ultrapure water; the dispersant is a C6 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether; the wetting agent is an isomeric C12-C14 alcohol polyoxyethylene ether; and the thickener is Arquad T-50.

[0037] The structural formula of the C6 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether is shown in formula (II), wherein p=q=5, and the structural formula of R2 is:

[0038] The structural formula of the isomeric C12-C14 alcohol polyoxyethylene ether is shown in formula (IV), wherein R4 is an isomeric C12-C14 fatty mixed alcohol, and a=3.

[0039] The method for preparing the diamond wire cutting fluid for improving the color difference of large-size silicon wafer cutting comprises the following steps:

[0040] Ultrapure water and thickener were added to the reactor in sequence, and the mixture was stirred at a speed of 1000 rpm for 30 minutes. After the solution was uniform and stable, dispersant and wetting agent were added in sequence, stirred for 2 hours, and aged for 1 hour.

[0041] Example 2: A diamond wire cutting fluid for improving color difference in cutting large-size silicon wafers

[0042] The diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers comprises the following components and their mass percentages: 22% dispersant, 24% wetting agent, 2% thickener, and 52% ultrapure water; the dispersant is a C4 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether; the wetting agent is an isomeric C12-C14 alcohol polyoxyethylene ether; and the thickener is Aromox 14D-W970.

[0043] The structural formula of the C4 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether is shown in formula (I), wherein R1 is n-butanol, and m=n=5.

[0044] The structural formula of the isomeric C12-C14 alcohol polyoxyethylene ether is shown in formula (IV), wherein R4 is an isomeric C12-C14 fatty mixed alcohol, and a=6.

[0045] The method for preparing the diamond wire cutting fluid for improving the color difference of large-size silicon wafer cutting comprises the following steps:

[0046] Ultrapure water and thickener were added to the reactor in sequence, and the mixture was stirred at a speed of 1500 rpm for 60 minutes. After the solution was uniform and stable, dispersant and wetting agent were added in sequence, stirred for 4 hours, and aged for 1 hour.

[0047] Example 3: A diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers

[0048] The diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers comprises the following components and their mass percentages: 18% dispersant, 22% wetting agent, 2.5% thickener, and 57.5% ultrapure water; the dispersant is a C8 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether; the wetting agent is an isomeric C12-C14 alcohol polyoxyethylene ether; and the thickener is Aromox MCD-W.

[0049] The structure of the C8 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether is shown in formula (III), wherein x=y=5, and the structure of R3 is

[0050] The structural formula of the isomeric C12-C14 alcohol polyoxyethylene ether is shown in formula (IV), wherein R4 is an isomeric C12-C14 fatty mixed alcohol, and a=4.

[0051] The method for preparing the diamond wire cutting fluid for improving the color difference of large-size silicon wafer cutting comprises the following steps:

[0052] Ultrapure water and thickener were added to the reactor in sequence, and the mixture was stirred at a speed of 1200 rpm for 50 minutes. After the solution was uniform and stable, dispersant and wetting agent were added in sequence, stirred for 3 hours, and aged for 1 hour.

[0053] Example 4: A diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers

[0054] The diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers comprises the following components and their mass percentages: 21% dispersant, 26% wetting agent, 4% thickener, and 49% ultrapure water; the dispersant is a C8 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether; the wetting agent is an isomeric C12-C14 alcohol polyoxyethylene ether; and the thickener is Aromox 14D-W970.

[0055] The structure of the C8 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether is shown in formula (III),

[0056] Wherein, x=y=20, and the structure of R3 is

[0057] The structural formula of the isomeric C12-C14 alcohol polyoxyethylene ether is shown in formula (IV), wherein R4 is an isomeric C12-C14 fatty mixed alcohol, and a=5.

[0058] The preparation method of the diamond wire cutting fluid for improving the color difference in cutting large-size silicon wafers is similar to that of Example 3.

[0059] Example 5: A diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers

[0060] The diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers comprises the following components and their mass percentages: 22% dispersant, 22.5% wetting agent, 2.5% thickener, and 53% ultrapure water; the dispersant comprises C4 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether and C6 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether in a mass ratio of 5:6; the wetting agent is isomeric C12-C14 alcohol polyoxyethylene ether; and the thickener comprises Arquad T-50 and Aromox 14D-W970 in a mass ratio of 2:3.

[0061] The preparation method of the diamond wire cutting fluid for improving the color difference in cutting large-size silicon wafers is similar to that of Example 3.

[0062] The structural formula of the C4 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether is shown in formula (I), wherein R1 is isobutanol, m=12, and n=15.

[0063] The structural formula of the C6 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether is shown in formula (II), wherein p=15, q=20, and the structural formula of R2 is:

[0064] The structural formula of the isomeric C12-C14 alcohol polyoxyethylene ether is shown in formula (IV), wherein R4 is an isomeric C12-C14 fatty mixed alcohol, and a=5.

[0065] Example 6: A diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers

[0066] The diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers comprises the following components and their mass percentages: 18% dispersant, 24% wetting agent, 3.5% thickener, and 54.5% ultrapure water; the dispersant is a C8 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether; the wetting agent is an isomeric C12-C14 alcohol polyoxyethylene ether; and the thickener is Aromox MCD-W.

[0067] The structure of the C8 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether is shown in formula (III),

[0068] Where x=10, y=20, and the structure of R3 is

[0069] The structural formula of the isomeric C12-C14 alcohol polyoxyethylene ether is shown in formula (IV), wherein R4 is an isomeric C12-C14 fatty mixed alcohol, and a=5.

[0070] The preparation method of the diamond wire cutting fluid for improving the color difference in cutting large-size silicon wafers is similar to that of Example 3.

[0071] Example 7: A diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers

[0072] The diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers comprises the following components and their mass percentages: 18% dispersant, 25% wetting agent, 5% thickener, and 52% ultrapure water; the dispersant is composed of a C4 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether and a C6 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether amine in a mass ratio of 4:5; the wetting agent is an isomeric C12-C14 alcohol polyoxyethylene ether; and the thickener is Aromox 14D-W970.

[0073] The structural formula of the C4 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether is shown in formula (I), wherein R1 is isobutanol, and m=n=20.

[0074] The structural formula of the C6 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether is shown in formula (II), wherein p=q=20, and the structural formula of R2 is:

[0075] The structural formula of the isomeric C12-C14 alcohol polyoxyethylene ether is shown in formula (IV), wherein R4 is an isomeric C12-C14 fatty mixed alcohol, and a=5.

[0076] The preparation method of the diamond wire cutting fluid for improving the color difference in cutting large-size silicon wafers is similar to that of Example 3.

[0077] Comparative Example 1: Diamond Wire Cutting Fluid

[0078] The diamond wire cutting fluid comprises the following components and their mass percentages: 22% dispersant, 22.5% wetting agent, 2.5% thickener, and 53% ultrapure water; the dispersant is composed of C4 alcohol single-terminated polyethylene oxide polypropylene oxide block polyether and C6 alcohol single-terminated polyethylene oxide polypropylene oxide block polyether in a mass ratio of 5:6; the wetting agent is isomeric C12-C14 alcohol polyoxyethylene ether; and the thickener is polyethylene glycol 400 distearate.

[0079] The structures of the C4 alcohol single-terminated polyethylene oxide polypropylene oxide block polyether, C6 alcohol single-terminated polyethylene oxide polypropylene oxide block polyether, and isomeric C12-C14 alcohol polyoxyethylene ether are the same as those in Example 5.

[0080] The preparation method of the diamond wire cutting fluid is similar to that of Example 3.

[0081] The difference from Example 5 is that the thickener is polyethylene glycol 400 distearate.

[0082] Comparative Example 2: Diamond Wire Cutting Fluid

[0083] The diamond wire cutting fluid comprises the following components and their mass percentages: 22% dispersant, 22.5% wetting agent, 2.5% thickener, and 53% ultrapure water; the dispersant comprises C4 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether and C6 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether in a mass ratio of 5:6; the wetting agent is isomeric C12-C14 alcohol polyoxyethylene ether; and the thickener comprises Arquad T-50 and Arquad 16-29 in a mass ratio of 2:3.

[0084] The structures of the C4 alcohol single-terminated polyethylene oxide polypropylene oxide block polyether, C6 alcohol single-terminated polyethylene oxide polypropylene oxide block polyether, and isomeric C12-C14 alcohol polyoxyethylene ether are the same as those in Example 5.

[0085] The difference from Example 5 is that the thickener consists of Arquad T-50 and Arquad 16-29 in a mass ratio of 2:3.

[0086] Test Example 1: Cutting Experiment

[0087] 1. Test samples: diamond wire cutting fluids prepared in Example 1, Example 2, Example 3, Example 4, Example 5, Example 6, Example 7, Comparative Example 1, and Comparative Example 2, as well as a commercially available diamond wire cutting fluid (TYWSi-1, manufactured by Jiangsu Dena Chemical Co., Ltd.).

[0088] 2. Test method:

[0089] Inside the cutting machine, the diamond wire cutting fluid is diluted with ultrapure water to a concentration of 0.25% to 1%. After this concentration is achieved, single crystal silicon wafers are cut with diamond wire. The slicing process involves the following steps: gluing the wire rods - slicing - debonding - cleaning - testing - sorting and packaging. After slicing, testing is performed.

[0090] 3. The test results are shown in Table 1.

[0091] Table 1: Cutting experiment results

[0092] As can be seen from Table 1, the A+ rate and color difference qualified rate of the diamond wire cutting fluid provided by Examples 1, 2, 3, 4, 5, 6, and 7 of the present invention are better than those of the commercially available products and the diamond wire cutting fluid obtained in Comparative Example 1 and Comparative Example 2. The A line mark rate, B thickness rate, and A edge chipping rate of the diamond wire cutting fluid provided by Examples 1, 2, 3, 4, 5, 6, and 7 of the present invention are lower than those of the commercially available products and the diamond wire cutting fluid obtained in Comparative Example 1 and Comparative Example 2. Compared with the commercially available products and the diamond wire cutting fluid obtained in Comparative Example 1 and Comparative Example 2, the color difference qualified rate of the diamond wire cutting fluid provided by Examples 1, 2, 3, 4, 5, 6, and 7 of the present invention is greatly improved. It can be seen that the diamond wire cutting fluid provided by the present invention can effectively improve the color difference of large-size silicon wafer cutting, and can substantially solve the problems of wire breakage, color difference, line mark, TTV, etc. in the production process of thinning and slicing, and greatly and effectively reduce the proportion of defective products produced during silicon wafer cutting.

[0093] Those skilled in the art should understand that the above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concepts disclosed herein shall be encompassed by the claims of the present invention.

Claims

1. A diamond wire cutting fluid for improving the chromatic aberration of large-size silicon wafer cutting, characterized in that: The invention comprises the following components and their mass percentages: 18-22% of a dispersant, 20-26% of a wetting agent, 2-5% of a thickener, and the balance of ultrapure water; the thickener is one or more of Arquad T-50, Aromox 14D-W970, and Aromox MCD-W.

2. The diamond wire cutting fluid for improving the chromatic aberration of large-size silicon wafer cutting according to claim 1, characterized in that: The invention comprises the following components and their mass percentages: 22% of dispersant, 22.5% of wetting agent, 2.5% of thickener and 53% of ultrapure water.

3. The diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers according to claim 1, characterized in that: The thickener is composed of Arquad T-50 and Aromox 14D-W970 in a mass ratio of 1-3:3-5.

4. The diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers as claimed in claim 3, characterized in that: The thickener is composed of Arquad T-50 and Aromox 14D-W970 in a mass ratio of 2:

3.

5. The diamond wire cutting fluid for improving the chromatic aberration of large-size silicon wafer cutting according to claim 1 or 2, characterized in that: The dispersant is one or more of C4 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether, C6 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether, and C8 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether.

6. The diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers as claimed in claim 5, characterized in that: The dispersant is composed of C4 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether and C6 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether in a mass ratio of 4-5:6-8.

7. The diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers according to claim 6, characterized in that: The dispersant is composed of C4 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether and C6 alcohol mono-terminated polyethylene oxide polypropylene oxide block polyether in a mass ratio of 5:

6.

8. The diamond wire cutting fluid for improving the chromatic aberration of large-size silicon wafer cutting according to claim 1 or 2, characterized in that: The wetting agent is isomeric C12-C14 alcohol polyoxyethylene ether.

9. The method for preparing a diamond wire cutting fluid for improving chromatic aberration in cutting large-size silicon wafers according to any one of claims 1 to 8, characterized in that: The following steps are involved: Add ultrapure water and thickener to the reaction kettle in sequence, stir at a stirring speed of 1000-1500 rpm for 30-60 minutes, and after the solution is uniform and stable, add dispersant and wetting agent in sequence, stir for 2-4 hours, and age for 1 hour to obtain the product.

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