A cooling liquid and a preparation method thereof

Abstract

The invention discloses a cooling liquid and a preparation method thereof, and relates to the field of cutting cooling technology. The cooling liquid comprises the following components in mass percentage: 1-10wt% of an extreme pressure agent, 1-5wt% of a rust inhibitor, 1-7wt% of a sedimentation agent, 1-10wt% of a penetrant, and 68-96wt% of deionized water. In the cooling liquid of the invention, the extreme pressure agent and the rust inhibitor in the cooling liquid form a solid protective film on the surface of a tool under cutting conditions such as high temperature and high pressure, thereby reducing the wear of the tool; the penetrant and the sedimentation agent reduce the amount of debris and dirt residue on the cutting surface of a wafer chip and make it cleaner, thereby reducing the cutting resistance of the tool dicing, thereby reducing the loss of the blade, improving the use efficiency of the blade, cutting more products in the same time, thereby extending the service life of the blade.

Description

Technical Field

[0001] The invention relates to the technical field of cutting cooling, and in particular to a cooling liquid and a preparation method thereof. Background Art

[0002] Wafer dicing is to divide the whole wafer into single chips or dies according to the chip size. It is an essential process in the back-end assembly process of the semiconductor chip manufacturing process. During the wafer cutting process, due to the strong mechanical force, the edge of the semiconductor wafer is prone to micro-cracks, edge collapse and stress concentration points. There is also uneven stress distribution and damage on the surface of the semiconductor wafer, which reduces the product yield.

[0003] In the cutting process, wafer chip coolant is usually used to improve the yield and processing accuracy of the cutting pieces.

[0004] However, the current chip cutting size is getting smaller and smaller, the cut grains are getting smaller and smaller, and the cutting debris is getting finer. The common wafer chip coolant on the market will shorten the life of the cutting tool. At the same time, the surface of the cut chip is more dirty and difficult to clean, resulting in a low product yield. Summary of the invention

[0005] The main purpose of the present invention is to provide a coolant and a preparation method thereof, aiming to solve the problem that the current wafer chip coolant shortens the life of the cutting tool.

[0006] To achieve the above object, the present invention provides a coolant, which comprises the following components in percentage by mass:

[0007] 1-10wt% of extreme pressure agent, 1-5wt% of rust inhibitor, 1-7wt% of sedimentation agent, 1-10wt% of penetrant, and 68-96wt% of deionized water.

[0008] In one embodiment, the extreme pressure agent includes one or more of polyoxyethylene polyoxypropylene ether ester, polyoxyethylene polyoxypropylene ether, water-based polyoxyethylene polyoxypropylene ether ester, nitrogen-molybdenum compound, sulfurized fatty acid ester, epoxyethylene epoxypropylene copolymer, and naphthol polyoxyethylene ether.

[0009] In one embodiment, the extreme pressure agent comprises polyoxyethylene polyoxypropylene ether ester and polyoxyethylene polyoxypropylene ether:

[0010] The mass ratio of the polyoxyethylene polyoxypropylene ether ester to the polyoxyethylene polyoxypropylene ether is 1:1; and / or,

[0011] The mass percentage of the extreme pressure agent in the coolant is 2 wt %.

[0012] In one embodiment, the rust inhibitor includes one or more of triethanolamine borate, benzotriazole, citric acid, hexamethylenetetramine, and sodium metasilicate pentahydrate.

[0013] In one embodiment, the rust inhibitor comprises hexamethylenetetramine and benzotriazole:

[0014] The mass ratio of the hexamethylenetetramine to the benzotriazole is 1:(1.5-2.5); and / or,

[0015] The mass percentage of the rust inhibitor in the coolant is 2-4 wt %.

[0016] In one embodiment, the sedimentation agent includes one or more of polyacrylamide graft copolymer, polyaluminum ferric chloride sulfate, polyaluminum chloride, amphoteric polyacrylamide copolymer, and quaternized polyacrylamide cationic sedimentation agent.

[0017] In one embodiment, the sedimentation agent comprises an amphoteric polyacrylamide copolymer, and the mass percentage of the sedimentation agent in the cooling liquid is 2-4 wt %.

[0018] In one embodiment, the penetrant includes one or more of a mixture of acetylene glycol polyether and isomeric alcohol polyether, isomeric alcohol polyoxyethylene ether, and acetylene glycol ethoxylate.

[0019] In one embodiment, the penetrant comprises acetylenic glycol polyether and isomeric alcohol polyether:

[0020] The mass ratio of the glycol polyether to the isomeric alcohol polyether is 1:(0.5-1.5); and / or,

[0021] The mass percentage of the penetrant in the coolant is 2-4 wt %.

[0022] The present invention also provides a method for preparing the aforementioned coolant, comprising the following steps:

[0023] The water and the extreme pressure agent are mixed for 3 to 7 minutes, the rust inhibitor is added and mixed for 3 to 7 minutes, the sedimentation agent is added and mixed for 3 to 7 minutes, and finally the penetrant is added and mixed for 8 to 12 minutes to obtain the coolant.

[0024] In the technical solution of the present invention, the extreme pressure agent and rust inhibitor in the coolant form a solid protective film on the surface of the tool under high temperature, high pressure and other cutting conditions, thereby reducing the wear of the tool; the sedimentation agent destroys the surface charge and van der Waals force of silicon pulverized chips, various metal chips and dirt generated in the cutting process, thereby making the chips easy to be carried away; in addition, the penetrant will wrap around the surface of the chips and dirt, thereby reducing the surface tension of the surface of the chips and dirt; at the same time, the penetrant will further penetrate into the interior of the chips and dirt to decompose the chips and dirt, thereby making the chips and dirt easy to be carried away; the chips and dirt on the cutting surface are easy to be carried away, which will also reduce the cutting resistance of the cutting surface, thereby improving the cutting efficiency of the blade and extending the service life of the blade.

[0025] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments. DETAILED DESCRIPTION

[0026] To make the purpose, technical scheme and advantages of the embodiment of the present invention clearer, the technical scheme in the embodiment of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiment, it is carried out according to the normal conditions or the conditions recommended by the manufacturer. If the reagents or instruments used do not specify the manufacturer, they are all conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes, taking "A and / or B" as an example, including scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, the technical schemes between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in the field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that the combination of such technical solutions does not exist, and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention.

[0027] Wafer dicing is the process of dividing the whole wafer into single chips or grains according to the chip size. It is an essential process in the back-end assembly process of the semiconductor chip manufacturing process. During the wafer cutting process, due to the strong mechanical force, the edge of the semiconductor wafer is prone to microcracks, edge collapse and stress concentration points. There is also uneven stress distribution and damage on the surface of the semiconductor wafer. These defects are important factors that cause a large number of secondary defects such as slip lines, epitaxial stacking faults, slip dislocations, micro defects, etc. in semiconductor wafer manufacturing, as well as the easy breakage of semiconductor wafers and chips, which also reduces the product yield.

[0028] In the cutting process, wafer chip coolant is usually used to improve the yield and processing accuracy of the cutting pieces.

[0029] However, currently the chip cutting size is getting smaller and smaller, the cut grains are getting smaller and smaller, and the cutting debris is getting finer. However, currently the chip cutting size is getting smaller and smaller, the cut grains are getting smaller and smaller, and the cutting debris is getting finer. The common wafer chip coolant on the market will shorten the life of the cutting tool. At the same time, the surface of the cut chip is dirty and difficult to clean, resulting in a low product yield.

[0030] In view of this, the present invention provides a coolant, which includes the following components in percentage by mass: 1-10wt% of extreme pressure agent, 1-5wt% of rust inhibitor, 1-7wt% of sedimentation agent, 1-10wt% of penetrant, and 68-96wt% of deionized water.

[0031] In the technical solution of the present invention, the extreme pressure agent and rust inhibitor in the coolant form a solid protective film on the surface of the tool under high temperature, high pressure and other cutting conditions, thereby reducing the wear of the tool; the sedimentation agent destroys the surface charge and van der Waals force of silicon pulverized chips, various metal chips and dirt generated in the cutting process, thereby making the chips easy to be carried away; the penetrant wraps around the surface of the chips and dirt, thereby reducing the surface tension of the surface of the chips and dirt; at the same time, the penetrant further penetrates into the interior of the chips and dirt to decompose the chips and dirt, thereby making the chips and dirt easy to be carried away; the chips and dirt on the cutting surface are easy to be carried away, which also reduces the cutting resistance of the cutting surface, thereby improving the cutting efficiency of the blade, extending the service life of the blade, and obtaining a product with a cleaner surface and a higher yield rate.

[0032] It should be noted that the penetrant and the sedimentation agent work together to reduce the amount of debris and dirt residue on the cut surface of the wafer chip and make it cleaner, thereby reducing the cutting resistance of the tool dicing, and then reducing the blade loss, improving the efficiency of the blade, cutting more products in the same time, thereby extending the service life of the blade. Therefore, the wafer chip coolant provided by the present invention has good lubricity, good cooling effect, can quickly take away cutting debris, is easy to clean the chip, extends the blade life, reduces the cutting cost, does not corrode the chip, and improves the product yield.

[0033] Therefore, the water-based wafer chip coolant of the present invention has good lubricity, good cooling effect, can quickly remove cutting debris, is easy to clean chips, prolongs the life of the blade, reduces cutting costs, does not corrode chips, and improves the yield of products. In addition, the coolant of the present invention has the advantage of low foaming, so that the foam will not be too high or overflow the cutting machine, making the site cleaner.

[0034] In some embodiments of the present invention, the mass concentration of the coolant is preferably 4% to 30%, more preferably 11%. The mass concentration of the coolant within the above range can ensure good lubricity, cooling effect and debris removal effect.

[0035] In some embodiments of the present invention, the mass percentage of deionized water is preferably 89%.

[0036] In some embodiments of the present invention, the extreme pressure agent includes one or more of polyoxyethylene polyoxypropylene ether ester, polyoxyethylene polyoxypropylene ether, aqueous polyoxyethylene polyoxypropylene ether ester, nitrogen-molybdenum compound, sulfurized fatty acid ester, epoxyethylene epoxypropylene copolymer, and naphthol polyoxyethylene ether. That is, the extreme pressure agent can be any one of polyoxyethylene polyoxypropylene ether ester, polyoxyethylene polyoxypropylene ether, aqueous polyoxyethylene polyoxypropylene ether ester, nitrogen-molybdenum compound, sulfurized fatty acid ester, epoxyethylene epoxypropylene copolymer, and naphthol polyoxyethylene ether, or can be two or more of polyoxyethylene polyoxypropylene ether ester, polyoxyethylene polyoxypropylene ether, aqueous polyoxyethylene polyoxypropylene ether ester, nitrogen-molybdenum compound, sulfurized fatty acid ester, epoxyethylene epoxypropylene copolymer, and naphthol polyoxyethylene ether, all within the protection scope of the present invention. Selecting the above-mentioned extreme pressure agent can form a stronger protective film on the surface of the tool more quickly, which can better reduce the wear of the tool. Among them, polyoxyethylene polyoxypropylene ether ester is a class of block copolymers of polyoxyethylene (PEO) and polyoxypropylene (PPO) produced by esterification reaction with fatty acids or other organic acids; polyoxyethylene polyoxypropylene ether is a block copolymer prepared by step-by-step addition polymerization of ethylene oxide and propylene oxide; compared with polyoxyethylene polyoxypropylene ether ester, the PEO chain in water-based polyoxyethylene polyoxypropylene ether ester is longer; nitrogen-molybdenum compounds refer to chemical substances containing two elements, nitrogen (N) and molybdenum (Mo); sulfurized fatty acid esters are compounds produced by the reaction of fatty acids with sulfur; ethylene oxide propylene oxide copolymers are polymer compounds produced by copolymerization of ethylene oxide (EO) and propylene oxide (PO); naphthol polyoxyethylene ether is produced by etherification reaction of naphthol and ethylene oxide.

[0037] In some embodiments of the present invention, the extreme pressure agent includes polyoxyethylene polyoxypropylene ether ester and polyoxyethylene polyoxypropylene ether: the mass ratio of the polyoxyethylene polyoxypropylene ether ester and the polyoxyethylene polyoxypropylene ether is 1:1. Compared with other extreme pressure agents, polyoxyethylene polyoxypropylene ether ester and polyoxyethylene polyoxypropylene ether can maintain good dispersibility and stability in aqueous solution, avoiding the emulsification problem that may be caused by oil-based extreme pressure agents. The mass ratio of polyoxyethylene polyoxypropylene ether ester and polyoxyethylene polyoxypropylene ether within the above range can quickly form a stronger protective film on the surface of the tool, which can better reduce the wear of the tool.

[0038] In some embodiments of the present invention, the extreme pressure agent includes polyoxyethylene polyoxypropylene ether ester and polyoxyethylene polyoxypropylene ether: the mass percentage of the extreme pressure agent in the coolant is 2wt%. The mass percentage of the extreme pressure agent within the above range can ensure that the tool wear is small and the service life is long.

[0039] In some embodiments of the present invention, the rust inhibitor includes one or more of triethanolamine borate, benzotriazole, citric acid, hexamethylenetetramine, and sodium metasilicate pentahydrate. That is, the rust inhibitor can be any one of triethanolamine borate, benzotriazole, citric acid, hexamethylenetetramine, and sodium metasilicate pentahydrate, or can be two or more of triethanolamine borate, benzotriazole, citric acid, hexamethylenetetramine, and sodium metasilicate pentahydrate, all within the protection scope of the present invention. Selecting the above-mentioned rust inhibitor can ensure that the coolant has less corrosive effect on the chip, and can form a protective film on the tool surface together with the extreme pressure agent, extend the tool life, and improve the chip yield.

[0040] In some embodiments of the present invention, the rust inhibitor includes hexamethylenetetramine and benzotriazole: the mass ratio of the hexamethylenetetramine to the benzotriazole is 1:(1.5-2.5). The mass ratio of the hexamethylenetetramine to the benzotriazole can be 1:1.5, 1:2 or 1:2.5, and the mass ratio within the above range can ensure that the corrosion effect on the chip and the tool is small.

[0041] In some embodiments of the present invention, the rust inhibitor includes hexamethylenetetramine and benzotriazole: the mass percentage of the rust inhibitor in the coolant is 2-4wt%. The mass percentage of the rust inhibitor can be 2wt%, 3wt% or 4wt%, and the mass percentage of the rust inhibitor within the above range can ensure that the coolant has less corrosive effect on the chip and the tool.

[0042] In some embodiments of the present invention, the sedimentation agent includes one or more of polyacrylamide graft copolymer, polyaluminum ferric sulfate chloride, polyaluminum chloride, amphoteric polyacrylamide copolymer, and quaternized polyacrylamide cationic sedimentation agent. That is, the sedimentation agent can be polyacrylamide graft copolymer, polyaluminum ferric sulfate chloride, polyaluminum chloride, amphoteric polyacrylamide copolymer, and quaternized polyacrylamide cationic sedimentation agent, or can be polyacrylamide graft copolymer, polyaluminum ferric sulfate chloride, polyaluminum chloride, amphoteric polyacrylamide copolymer, and quaternized polyacrylamide cationic sedimentation agent, all of which are within the protection scope of the present invention. The selection of the above sedimentation agent can better destroy the surface charge and van der Waals force of debris and dirt, so that the force between the debris and dirt and the chip is weakened, and it is easy to be taken away by the flowing coolant, thereby better improving the yield rate of the chip. Among them, polyacrylamide graft copolymer refers to a copolymer with a branched structure formed by combining polyacrylamide (PAM) with another monomer or polymer segment through a chemical reaction. The polyacrylamide graft copolymer has a better sedimentation effect, and the formed sediment will not condense into blocks; polyaluminum ferric chloride sulfate is a multinuclear hydroxyl complex composed of iron, aluminum, chloride and sulfate ions; polyaluminum chloride is a multinuclear hydroxyl complex composed of aluminum ions and chloride ions; amphoteric polyacrylamide copolymer is a polyacrylamide copolymer containing both cationic and anionic functional groups, and a copolymer with amphoteric charges is formed by introducing cationic monomers (such as dimethyldiallyl ammonium chloride) and anionic monomers (such as acrylic acid) into the main chain of polyacrylamide; quaternized polyacrylamide cationic sedimentation agent is a cationic polyacrylamide copolymer formed by combining polyacrylamide with a cationic monomer of a quaternary ammonium salt group (such as dimethyldiallyl ammonium chloride) through a chemical reaction.

[0043] In some embodiments of the present invention, the sedimentation agent includes an amphoteric polyacrylamide copolymer, and the mass percentage of the sedimentation agent in the coolant is 2-4wt%. The mass percentage of the sedimentation agent can be 2wt%, 3wt% or 4wt%, and the mass percentage of the sedimentation agent within the above range can ensure that the coolant can better destroy the surface charge and van der Waals force of debris and dirt, so that the force between the debris and dirt and the chip is weakened and easily taken away by the flowing coolant, thereby better improving the chip yield.

[0044] In some embodiments of the present invention, the penetrant includes one or more of a mixture of acetylene glycol polyether and isomeric alcohol polyether, isomeric alcohol polyoxyethylene ether, and acetylene glycol ethoxylate. That is, the penetrant can be a mixture of acetylene glycol polyether and isomeric alcohol polyether, isomeric alcohol polyoxyethylene ether, and acetylene glycol ethoxylate, or a mixture of acetylene glycol polyether and isomeric alcohol polyether, isomeric alcohol polyoxyethylene ether, and acetylene glycol ethoxylate, all of which are within the protection scope of the present invention. The above-mentioned penetrant can be selected to better penetrate the debris and dirt inside to decompose them, and they are easily taken away by the flowing coolant. Among them, the mixture of acetylene glycol polyether and isomeric alcohol polyether is prepared by mixing acetylene glycol polyether and isomeric alcohol polyether in a certain proportion; isomeric alcohol polyoxyethylene ether is prepared by the addition reaction of isomeric alcohols (such as isotridecanol, isononanol, etc.) and ethylene oxide; acetylene glycol ethoxylate refers to a compound prepared by the addition reaction of acetylene glycol (such as 2,4,7,9-tetramethyl-5-decyne-4,7-diol) and ethylene oxide.

[0045] In some embodiments of the present invention, the penetrant includes acetylene glycol polyether and isomeric alcohol polyether: the mass ratio of the acetylene glycol polyether to the isomeric alcohol polyether is 1:(0.5-1.5). The mass ratio of the acetylene glycol polyether to the isomeric alcohol polyether can be 1:0.5, 1:1 or 1:1.5, and the mass ratio within the above range can ensure a good decomposition effect on debris and dirt.

[0046] In some embodiments of the present invention, the penetrant includes acetylene glycol polyether and isomeric alcohol polyether: the mass percentage of the penetrant in the coolant is 2-4wt%. The mass percentage of the penetrant can be 2wt%, 3wt% or 4wt%, and the mass percentage of the penetrant within the above range can ensure that the coolant can penetrate and decompose debris and dirt well.

[0047] The present invention also provides a method for preparing the aforementioned coolant, comprising the following steps: mixing water and an extreme pressure agent for 3 to 7 minutes, adding a rust inhibitor and mixing for 3 to 7 minutes, then adding a sedimentation agent and mixing for 3 to 7 minutes, and finally adding a penetrant and mixing for 8 to 12 minutes to obtain the coolant.

[0048] In the technical solution of the present invention, the order of adding materials can make each raw material dissolve well in the solvent, so that the uniformity of the coolant is better.

[0049] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention, and are not used to limit the present invention.

[0050] Example 1

[0051] A coolant comprising the following components in percentage by mass:

[0052] 5wt% mixture of polyoxyethylene polyoxypropylene ether ester and polyoxyethylene polyoxypropylene ether, 5wt% hexamethylenetetramine, 5wt% quaternized polyacrylamide cationic sedimentation agent, 5wt% mixture of acetylene glycol polyether and isomeric alcohol polyether, and the balance of water. All raw materials were purchased from Tianjin Haolian Technology Development Co., Ltd.

[0053] Example 2

[0054] A coolant comprising the following components in percentage by mass:

[0055] 2wt% nitrogen-molybdenum compound, 3wt% hexamethylenetetramine, 2wt% triethanolamine borate, 3wt% polyferric aluminum sulfate chloride, 5wt% isomeric alcohol polyoxyethylene ether, and the balance is water. All raw materials were purchased from Tianjin Haolian Technology Development Co., Ltd.

[0056] Example 3

[0057] A coolant comprising the following components in percentage by mass:

[0058] Waterborne polyoxyethylene polyoxypropylene ether ester 4wt%, sulfurized fatty acid ester 5wt%, citric acid 2wt%, polyacrylamide graft copolymer 3wt%, acetylene glycol ethoxylate 5wt%, water balance. All raw materials were purchased from Tianjin Haolian Technology Development Co., Ltd.

[0059] Example 4

[0060] A coolant comprising the following components in percentage by mass:

[0061] 2wt% mixture of polyoxyethylene polyoxypropylene ether ester and polyoxyethylene polyoxypropylene ether, 3wt% mixture of hexamethylenetetramine and benzotriazole, 3wt% amphoteric polyacrylamide copolymer, 3wt% mixture of acetylene glycol polyether and isomeric alcohol polyether, and the balance of water. All raw materials were purchased from Tianjin Haolian Technology Development Co., Ltd.

[0062] Example 5

[0063] A method for preparing a coolant, wherein the formula of the coolant is the same as that of Example 1, comprising the following steps:

[0064] 1. Add accurately weighed water into the stainless steel reactor and start stirring until the preparation process is completed;

[0065] 2. Add extreme pressure agent in sequence and stir for 5 minutes;

[0066] 3. Add rust inhibitors in sequence and stir for 5 minutes;

[0067] 4. Add sedimentation agents in sequence and stir for 5 minutes;

[0068] 5. Add the penetrant into the stainless steel reactor in sequence and stir for 10 minutes to obtain a colorless and transparent coolant;

[0069] 6. Finally, store the prepared aqueous low-foam wafer chip coolant in sealed cans to avoid prolonged exposure to the air.

[0070] Comparative Example 1

[0071] An existing coolant is provided, which is purchased from Guangdong Jufu Energy Saving Technology Co., Ltd. and has a product number of TUW-1296.

[0072] The coolant stock solutions in Examples 1 to 4 and Comparative Example 1 were subjected to four-ball friction (Qingdao Zhongke Runmei Lubricating Material Technology Co., Ltd.), pH (pH meter), surface tension (surface tension meter, mN / m), conductivity (conductivity tester, μs / cm), copper and aluminum corrosion test (red copper that meets the national standard GB / T5213 and LY12 aluminum of GB / T3190 were immersed in 55°C cutting fluid separately for 24 hours), blade life and yield tests, and the results are shown in Table 1.

[0073] Table 1 Performance characteristics of the coolant stock solution in Examples 1 to 4 and Comparative Example 1

[0074]

[0075] In summary, the coolant of the present invention has good lubricity and wear resistance, can guide away cutting debris in a timely manner, reduce resistance during cutting, and can extend the life of the blade by about 8 to 16% (compared with the comparative example), reduce scratches, broken edges and other defects on the cutting surface, and increase the cutting yield by about 1%. In addition, the coolant of the present invention does not add organic solvents, is non-volatile, has little odor, has stable performance, and is harmless to the human body; the present invention does not corrode metals such as copper and aluminum, and does not affect the post-cutting process. The present invention is easy to clean, with no residue or watermark on the surface. The present invention is an aqueous mixed system, is non-flammable, and is safe to use.

[0076] The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the patent protection scope of the present invention.

Claims

1. A cooling liquid, characterized in that: The coolant includes the following components in mass percentage: 1-10wt% of extreme pressure agent, 1-5wt% of rust inhibitor, 1-7wt% of sedimentation agent, 1-10wt% of penetrant, and 68-96wt% of deionized water.

2. The coolant according to claim 1, characterized in that The extreme pressure agent includes one or more of polyoxyethylene polyoxypropylene ether ester, polyoxyethylene polyoxypropylene ether, water-based polyoxyethylene polyoxypropylene ether ester, nitrogen-molybdenum compound, sulfurized fatty acid ester, epoxyethylene epoxypropylene copolymer, and naphthol polyoxyethylene ether.

3. The cooling liquid according to claim 2, characterized in that The extreme pressure agent includes polyoxyethylene polyoxypropylene ether ester and polyoxyethylene polyoxypropylene ether: The mass ratio of the polyoxyethylene polyoxypropylene ether ester to the polyoxyethylene polyoxypropylene ether is 1:1; and / or, The mass percentage of the extreme pressure agent in the coolant is 2 wt %.

4. The coolant according to claim 1, characterized in that The rust inhibitor includes one or more of triethanolamine borate, benzotriazole, citric acid, hexamethylenetetramine, and sodium metasilicate pentahydrate.

5. The cooling liquid according to claim 4, characterized in that The rust inhibitor includes hexamethylenetetramine and benzotriazole: The mass ratio of the hexamethylenetetramine to the benzotriazole is 1:(1.5-2.5); and / or, The mass percentage of the rust inhibitor in the coolant is 2-4 wt %.

6. The cooling liquid according to claim 1, characterized in that The sedimentation agent includes one or more of polyacrylamide graft copolymer, polyaluminum ferric sulfate chloride, polyaluminum chloride, amphoteric polyacrylamide copolymer, and quaternized polyacrylamide cationic sedimentation agent.

7. The cooling liquid according to claim 6, characterized in that The sedimentation agent comprises an amphoteric polyacrylamide copolymer, and the mass percentage of the sedimentation agent in the cooling liquid is 2-4wt%.

8. The cooling liquid according to claim 1, characterized in that The penetrant includes one or more of a mixture of acetylene glycol polyether and isomeric alcohol polyether, isomeric alcohol polyoxyethylene ether, and acetylene glycol ethoxylate.

9. The cooling liquid according to claim 8, characterized in that The penetrants include acetylenic glycol polyethers and isomeric alcohol polyethers: The mass ratio of the glycol polyether to the isomeric alcohol polyether is 1:(0.5-1.5); and / or, The mass percentage of the penetrant in the coolant is 2-4 wt %.

10. A method for preparing a coolant according to any one of claims 1 to 9, characterized in that: The following steps are involved: The water and the extreme pressure agent are mixed for 3 to 7 minutes, the rust inhibitor is added and mixed for 3 to 7 minutes, the sedimentation agent is added and mixed for 3 to 7 minutes, and finally the penetrant is added and mixed for 8 to 12 minutes to obtain the coolant.

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