CN115975711A - Improve dispersibility, reduce foam type diamond wire silicon chip cutting fluid and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of diamond wire silicon wafer cutting fluid and its preparation, and in particular relates to a diamond wire silicon wafer cutting fluid with improved dispersion and reduced foam and a preparation method thereof. The dispersibility-improving and foam-reducing diamond wire silicon wafer cutting fluid is composed of the following raw materials in mass fractions: 30-50% lubricant, 1-5% dispersant, 10-20% penetrant, and defoamer 0.5 to 5%, chelating agent 1 to 5%, antioxidant 0.5 to 2%, and the balance is deionized water; the dispersant is a polyethylene glycol derivative containing a quaternary ammonium salt, and its number average molecular weight is 500‑700. The invention provides a diamond wire silicon wafer cutting fluid, which belongs to a low-foam cutting fluid and has the characteristic of high dispersibility; the invention also provides a preparation method thereof.

Description

Diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming and preparation method thereof

Technical Field

The invention belongs to the technical field of diamond wire silicon wafer cutting fluid and preparation thereof, and specifically relates to a diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foam and a preparation method thereof.

Background Art

At present, there are two main methods of silicon wafer cutting: free abrasive slurry cutting and diamond wire cutting. Compared with traditional free abrasive slurry cutting, diamond wire cutting has the advantages of fast cutting speed (4-5 times the cutting speed), high wafer output rate (silicon wafer output exceeds 15-20%), energy saving (water and electricity consumption is reduced by two-thirds), and low pollution. It can greatly reduce the production cost of silicon wafer manufacturers and improve the photovoltaic installation rate of return. Therefore, the diamond wire cutting process has gradually been widely used in the industry. With the rapid development of the photovoltaic industry, the demand for silicon wafers as its basic material has also increased. The important process of silicon wafer processing is slicing. The defects such as silicon wafer stress, surface and sub-surface damage and edge collapse generated during slicing will seriously affect the conversion efficiency of photovoltaic cells, and the performance of the cutting fluid is one of the key factors affecting the efficiency and quality of silicon wafer cutting.

Diamond wire cutting fluid should have the following functions: (1) Lubrication: The cutting fluid should penetrate into the wire mesh and silicon wafer, and between the wire mesh and debris in time to form a lubricating protective film to reduce cutting resistance, thereby reducing damage, wire marks and hidden cracks caused by the diamond wire; (2) Cooling: In addition to part of the high heat generated by cutting being taken away by the cutting fluid, most of the remaining heat is absorbed by the crystalline silicon. High temperature will cause local deformation of the silicon wafer. Therefore, the cutting fluid must have good heat transfer and cooling performance; (3) Dispersion: The silicon powder chips formed by cutting need to be dispersed in time to avoid agglomeration, causing scratches on the silicon wafer or even wire mesh breakage; (4) Cleaning: The large amount of debris and silicon powder generated during the cutting process are prone to form adhesion agglomerations. Therefore, the cutting fluid is required to wrap the debris to make it easy to fall off and clean; (5) The cutting fluid should also have the ability to prevent rust and inhibit bacteria to avoid production interruptions due to corrosion during long-term use of the equipment.

As mentioned above, due to the exponential increase in the speed of the diamond wire, the amount of silicon powder cut off will also increase exponentially. If it is not moistened and dispersed in time, it will gather on the surface of the silicon wafer, causing scratches on the silicon wafer and even wire breakage. Therefore, the dispersion of the cutting fluid is required to be higher. Another important thing is that when cutting and cleaning silicon wafers, a large amount of foam is often generated, which seriously affects the cutting efficiency, resulting in excessive consumption of cutting fluid and rising costs. Over time, it will also damage mechanical equipment and reduce the life of the machinery.

Summary of the invention

The technical problem to be solved by the present invention is to provide a diamond wire silicon wafer cutting liquid, which is a low-foam cutting liquid and has the characteristic of high dispersibility; the present invention also provides a preparation method thereof.

The diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming of the present invention is composed of the following raw materials in mass fractions:

The balance is deionized water;

The dispersant is a polyethylene glycol derivative containing a quaternary ammonium salt, and the number average molecular weight thereof is 500-700, preferably 500, 600, or 700.

The lubricant is a compound of trans-block polyether polyol 1740 and trans-block polyether polyol 1720 mixed in a weight ratio of 1/2 to 2/1.

The cloud point of a 1% aqueous solution of trans-block polyether polyol 1740 is 50±2°C, and the cloud point of a 1% aqueous solution of trans-block polyether polyol 1720 is 35±2°C.

The dispersant is an intermediate generated by ring-opening polymerization of ethylene oxide with N,N'-dimethylethanolamine as an initiator under the action of potassium hydroxide as a catalyst, desalted by magnesium silicate adsorbent, and finally neutralized with acetic acid to generate a polyethylene glycol derivative containing quaternary ammonium salt. The general formula of quaternary ammonium salt is R ₁ R ₂ R ₃ NX, where R ₁ and R ₂ are both -CH ₃ structures, R ₃ is -(CH ₂ )-O-(CH ₂ -CH ₂ -O)nH structure, and X is CH ₃ CH ₂ COO ^- structure).

The penetrant is one or more of isomeric octanol polyoxyethylene ether, isomeric decanol polyoxyethylene ether, and isomeric tridecanol polyoxyethylene ether.

The defoaming agent is one or more of polyoxypropylene ether, GPES type stearate polyoxyethylene polyoxypropylene glycerol ether, and dodecyne glycol polyether.

The chelating agent is one or more of disodium EDTA, tetrasodium EDTA, and disodium citrate.

The antioxidant is a water-soluble antioxidant, including one or more of vitamin C, tea polyphenols, and disodium stannous citrate.

The method for preparing the diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming comprises the following steps:

(1) Add deionized water into the reaction kettle according to the formula ratio, and heat it to 35-40° C. while stirring;

(2) Adding a lubricant, a dispersant, a penetrant, a defoaming agent, a chelating agent and an antioxidant to the reaction kettle in order, stirring for 1 to 2 hours, and filtering to obtain a diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming.

The lubricant added to the formula of the present invention is a compound of trans-block polyether polyol 1740 and 1720 mixed in a weight ratio of 1/2 to 2/1. The compound has excellent low foaming and lubricity, and has good compatibility with other formula products. Trans-block polyether polyol 1740 is preferably produced by Shanghai Dongda Chemical Co., Ltd. Trans-block polyether polyol 1720 is preferably produced by Shanghai Dongda Chemical Co., Ltd.

The dispersant in the formula of the present invention adopts a polyethylene glycol derivative containing a quaternary ammonium salt, which is adsorbed on the surface of the cut silicon powder. Due to the electrostatic repulsion force and the steric hindrance effect, the dispersibility of the silicon powder in the cutting fluid is greatly improved, and the quaternary ammonium salt contained in the polyethylene glycol derivative not only has a highly effective bactericidal performance, but also has low toxicity and is non-irritating to human organs and skin.

The penetrant in the formula of the present invention is preferably isomeric alcohol polyoxyethylene ether, which not only has excellent permeability and emulsification, but also has lower foam height and poor foam stability compared with traditional fatty alcohol polyvinyl ether penetrants.

The defoaming agent in the formulation of the present invention is preferably polyoxypropylene ether, which can play a long-term defoaming and anti-foaming role in the formulation of the cutting fluid. The existing modified silicon polyether defoaming agent is not used in the cutting fluid because it is easy to produce silicon spots on the surface of the silicon wafer.

The chelating agent in the formula of the present invention is one or more of disodium EDTA, tetrasodium EDTA and disodium citrate, which can remove iron ions generated in the diamond wire cutting process during the use of the cutting fluid, thereby further reducing the pollution to the surface of the silicon wafer.

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

(1) The cutting fluid of the present invention uses a compound of trans-block polyether 1740/1720 as a lubricant. During the diamond wire cutting process, the cutting fluid penetrates into the cutting gap. Due to the high temperature generated by high-speed friction, 1740/1720 is precipitated and attached to the wire mesh and silicon wafer, and the wire mesh and silicon powder, and a reversible lubricating film is formed on the surface, which reduces the cutting resistance and greatly reduces the degree of damage to the cutting wire and silicon wafer. In addition, the compound lubricant has excellent low foaming and defoaming properties, and can reduce the generation of foam.

(2) The cutting fluid of the present invention uses a polyethylene glycol derivative containing a quaternary ammonium salt as a dispersant. During the cutting process, the cutting fluid quickly penetrates into the cutting gap, and the polyethylene glycol derivative is quickly adsorbed on the surface of the silicon powder by hydrogen bonds and other forces. Due to the dual effects of electrostatic repulsion and steric hindrance, the silicon powder is dispersed in time, preventing the silicon powder from agglomerating. In addition, the quaternary ammonium salt contained in the polyethylene glycol derivative not only has a highly effective bactericidal performance, but also has low toxicity and is non-irritating to human organs and skin.

(3) The isomeric alcohol polyoxyethylene ether is used as a penetrant in the cutting fluid formula of the present invention. It not only has excellent permeability and emulsification properties, but also has a lower foam height, poorer foam stability, and a faster defoaming speed than traditional fatty alcohol polyoxyethylene ether penetrants.

(4) The lubricant, penetrant, dispersant and defoamer in the cutting fluid formula of the present invention are all polyethers, which have good compatibility and the prepared cutting fluid has strong stability.

DETAILED DESCRIPTION

The present invention is further described below in conjunction with specific examples. The following raw materials and reagents are all commercially available products.

Example 1

The diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foam is composed of the following raw materials in mass fractions:

Lubricant: a mixture of trans-block polyether polyol 1740 and 1720 in a weight ratio of 1/1, 35%;

Dispersant: polyethylene glycol derivative containing quaternary ammonium salt, number average molecular weight 500, 2.5%;

Penetrant: isomeric decanol polyoxyethylene ether, 20%;

Defoaming agent: polyoxypropylene ether, 2%;

Chelating agent: disodium EDTA, 2.5%;

Antioxidant: tea polyphenols, 1.0%;

Deionized water: 37%; the total amount of each component is 100%.

The method for preparing the diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming comprises the following steps:

(1) Add deionized water into the reaction kettle according to the formula ratio, and heat it to 35°C while stirring;

(2) Add the above-mentioned lubricant, dispersant, penetrant, defoamer, chelating agent and antioxidant to the reaction kettle in order, stir for 1 hour, and filter to obtain a diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming.

Example 2

The diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foam is composed of the following raw materials in mass fractions:

Lubricant: a mixture of trans-block polyether polyol 1740 and 1720 in a weight ratio of 1/1, 40%;

Dispersant: polyethylene glycol derivative containing quaternary ammonium salt, number average molecular weight 500, 2.5%;

Penetrant: isomeric decanol polyoxyethylene ether, 16%;

Defoaming agent: polyoxypropylene ether 1%, dodecyne glycol polyether 1%;

Chelating agent: Tetrasodium EDTA, 1%;

Antioxidant: disodium stannous citrate, 2.0%;

Deionized water: 36.5%; the total amount of each component is 100%.

The method for preparing the diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming comprises the following steps:

(1) Add deionized water into the reaction kettle according to the formula ratio, and heat it to 40°C while stirring;

(2) Add the above-mentioned lubricant, dispersant, penetrant, defoamer, chelating agent and antioxidant to the reaction kettle in order, stir for 2 hours, and filter to obtain a diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming.

Example 3

The diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foam is composed of the following raw materials in mass fractions:

Lubricant: a mixture of trans-block polyether polyol 1740 and 1720 in a weight ratio of 1/1, 45%;

Dispersant: polyethylene glycol derivative containing quaternary ammonium salt, number average molecular weight 500, 3%;

Penetrant: isomeric decanol polyoxyethylene ether, 15%;

Defoaming agent: GPES type stearate polyoxyethylene polyoxypropylene glyceryl ether, 2%;

Chelating agent: disodium EDTA, 2%;

Antioxidants: Vitamin C 0.5%, tea polyphenols 0.5%, disodium stannous citrate 0.5%;

Deionized water: 31.5%; the total amount of each component is 100%.

The method for preparing the diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming comprises the following steps:

(1) Add deionized water into the reaction kettle according to the formula ratio, and heat it to 35°C while stirring;

(2) Add the above-mentioned lubricant, dispersant, penetrant, defoamer, chelating agent and antioxidant to the reaction kettle in order, stir for 1.5 hours, and filter to obtain a diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming.

Example 4

The diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foam is composed of the following raw materials in mass fractions:

Lubricant: a mixture of trans-block polyether polyol 1740 and 1720 in a weight ratio of 1/1, 50%;

Dispersant: polyethylene glycol derivative containing quaternary ammonium salt, number average molecular weight 500, 1%;

Penetrant: isomeric tridecanol polyoxyethylene ether 6%, isomeric decanol polyoxyethylene ether 6%;

Defoaming agent: polyoxypropylene ether, 2%;

Chelating agent: disodium EDTA, 2.5%;

Antioxidants: tea polyphenols, 1.5%;

Deionized water: 31%; the total amount of each component is 100%.

The method for preparing the diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming comprises the following steps:

(1) Add deionized water into the reaction kettle according to the formula ratio, and heat it to 35°C while stirring;

(2) Add the above-mentioned lubricant, dispersant, penetrant, defoamer, chelating agent and antioxidant to the reaction kettle in order, stir for 1 hour, and filter to obtain a diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming.

Example 5

The diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foam is composed of the following raw materials in mass fractions:

Lubricant: a mixture of trans-block polyether polyol 1740 and 1720 in a weight ratio of 1/1, 45%;

Dispersant: polyethylene glycol derivative containing quaternary ammonium salt, number average molecular weight 500, 5%;

Penetrant: isomeric octanol polyoxyethylene ether, 15%;

Defoaming agent: polyoxypropylene ether, 2%;

Chelating agent: disodium EDTA, 5%;

Antioxidant: tea polyphenols, 1.0%;

Deionized water: 27%; the total amount of each component is 100%.

The method for preparing the diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming comprises the following steps:

(1) Add deionized water into the reaction kettle according to the formula ratio, and heat it to 35°C while stirring;

(2) Add the above-mentioned lubricant, dispersant, penetrant, defoamer, chelating agent and antioxidant to the reaction kettle in order, stir for 1 hour, and filter to obtain a diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming.

Example 6

The diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foam is composed of the following raw materials in mass fractions:

Lubricant: a mixture of trans-block polyether polyol 1740 and 1720 in a weight ratio of 1/1, 30%;

Dispersant: polyethylene glycol derivative containing quaternary ammonium salt, number average molecular weight 700, 3%;

Penetrant: isomeric decanol polyoxyethylene ether, 10%;

Defoaming agent: polyoxypropylene ether, 5%;

Chelating agents: disodium EDTA 1%, disodium citrate 1%;

Antioxidant: tea polyphenols, 0.5%;

Deionized water: 49.5%; the total amount of each component is 100%.

The method for preparing the diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming comprises the following steps:

(1) Add deionized water into the reaction kettle according to the formula ratio, and heat it to 35°C while stirring;

(2) Add the above-mentioned lubricant, dispersant, penetrant, defoamer, chelating agent and antioxidant to the reaction kettle in order, stir for 1 hour, and filter to obtain a diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming.

Example 7

The diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foam is composed of the following raw materials in mass fractions:

Lubricant: a mixture of trans-block polyether polyol 1740 and 1720 in a weight ratio of 1/2, 45%;

Dispersant: polyethylene glycol derivative containing quaternary ammonium salt, number average molecular weight 600, 3%;

Penetrant: isomeric decanol polyoxyethylene ether, 15%;

Defoaming agent: polyoxypropylene ether, 0.5%;

Chelating agent: disodium citrate, 3.5%;

Antioxidants: tea polyphenols, 1.5%;

Deionized water: 31.5%; the total amount of each component is 100%.

The method for preparing the diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming comprises the following steps:

(1) Add deionized water into the reaction kettle according to the formula ratio, and heat it to 35°C while stirring;

(2) Add the above-mentioned lubricant, dispersant, penetrant, defoamer, chelating agent and antioxidant to the reaction kettle in order, stir for 1 hour, and filter to obtain a diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming.

Example 8

The diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foam is composed of the following raw materials in mass fractions:

Lubricant: a mixture of trans-block polyether polyol 1740 and 1720 in a weight ratio of 2/1, 35%;

Dispersant: polyethylene glycol derivative containing quaternary ammonium salt, number average molecular weight 500, 2.5%;

Penetrant: isomeric decanol polyoxyethylene ether, 18%;

Defoaming agent: polyoxypropylene ether, 2%;

Chelating agent: disodium EDTA, 2.5%;

Antioxidant: tea polyphenols, 1.0%;

Deionized water: 39%; the total amount of each component is 100%.

The method for preparing the diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming comprises the following steps:

(1) Add deionized water into the reaction kettle according to the formula ratio, and heat it to 35°C while stirring;

(2) Add the above-mentioned lubricant, dispersant, penetrant, defoamer, chelating agent and antioxidant to the reaction kettle in order, stir for 1 hour, and filter to obtain a diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foaming.

Comparative Example 1

A diamond wire silicon wafer cutting fluid, the raw materials of which are: 45% lubricant (1740 and 1720 in a mass ratio of 1/1), 3% dispersant (polyethylene glycol 500), 15% penetrant (isomeric decanol polyoxyethylene ether), 2% defoamer (polyoxypropylene ether), 2% chelating agent (EDTA disodium), 1.5% antioxidant (tea polyphenols), and 31.5% deionized water. The total amount of each component is 100%.

The preparation method is as follows:

(1) Add deionized water into the reactor in proportion and heat to 35°C while stirring;

(2) Add lubricant, dispersant, penetrant, defoamer, chelating agent and antioxidant to the reaction kettle in order, stir for 1 hour, and filter to obtain silicon wafer cutting liquid.

Comparative Example 2

A diamond wire silicon wafer cutting fluid, the raw materials of which are: 45% lubricant (1740 and 1720 in a mass ratio of 1/1), 3% dispersant (polyethylene glycol derivative containing quaternary ammonium salt, with a number average molecular weight of 500), 15% penetrant (isomeric decanol polyoxyethylene ether), 2% chelating agent (disodium EDTA), 1.5% antioxidant (tea polyphenols), and 33.5% deionized water. The total amount of each component is 100%.

The preparation method is as follows:

(1) Add deionized water into the reactor in proportion and heat to 35°C while stirring;

(2) Add lubricant, dispersant, penetrant, chelating agent and antioxidant to the reaction kettle in order, stir for 1 hour, and filter to obtain silicon wafer cutting liquid.

Comparative Example 3

A diamond wire silicon wafer cutting fluid, the raw materials of which are: 45% lubricant (1720), 3% dispersant (polyethylene glycol derivative containing quaternary ammonium salt, number average molecular weight of 500), 15% penetrant (isomeric decanol polyoxyethylene ether), 2% defoamer (polyoxypropylene ether), 2% chelating agent (disodium EDTA), 1.5% antioxidant (tea polyphenols), and 31.5% deionized water. The total amount of each component is 100%.

The preparation method is as follows:

(1) Add deionized water into the reactor in proportion and heat to 35°C while stirring;

(2) Add lubricant, dispersant, penetrant, defoamer, chelating agent and antioxidant to the reaction kettle in order, stir for 1 hour, and filter to obtain silicon wafer cutting liquid.

(I) The performance parameters of the diamond wire silicon wafer cutting fluid prepared in the above Examples 1-8 and Comparative Examples 1-4 were tested under the following test conditions:

The cutting liquid was diluted to 1% and the conductivity was tested at 25±1°C; the instrument model was S230SevenCompact conductivity meter.

Dilute the cutting fluid at 1:1000 and test its COD. The instrument model is 6B-300 water quality rapid tester

The wetting time of the cutting fluid is tested at 25±1°C with a 0.1% dilution according to the canvas sedimentation permeability test method.

The cutting fluid was diluted to 0.5% and conditioned at 23°C for 15 minutes with an initial volume of 1000 mL to measure the circulating foam height and defoaming time. The instrument model was the HCR-700 metal cutting fluid anti-foam tester.

The mass ratio of cutting fluid to silicon powder is 1:1. After 24 hours at 25±1°C, the suspension rate is measured. The dispersibility is characterized by measuring the suspension ability of the cutting fluid on the silicon powder. After the cutting fluid and silicon powder are uniformly mixed in a mass ratio of 1:1, they are allowed to stand in a 100mL stoppered measuring cylinder, and the sedimentation height h of the silicon powder in the cutting fluid is recorded. The suspension rate = (100-h)*100%/100.

The above test results are shown in Table 1.

Table 1 Test results

(ii) The diamond wire silicon wafer cutting fluid prepared in the above embodiments and comparative examples was diluted 300 times with deionized water and then used to cut silicon crystals of the same material. The test results are shown in Table 2.

Table 2 Cutting data results

As can be seen from Table 1, the cutting fluid using a polyethylene glycol derivative containing a quaternary ammonium salt as a dispersant has a better dispersion effect than the polyethylene glycol dispersant, and has a better effect in preventing silicon powder from agglomerating on the silicon wafer. The cutting fluid without a defoaming agent also has good anti-foaming and defoaming properties.

As can be seen from Table 2, the cutting fluid of the present invention has excellent penetration and lubrication properties, a very low incidence of surface defects, and a low wire breakage rate and overcutting rate; the polyethylene glycol derivative containing quaternary ammonium salt has better dispersibility than polyethylene glycol, improves cleaning efficiency, and reduces the proportion of dirt. Using 1720 as a lubricant, because its hydrophilicity is weaker than 1740, the contamination rate is slightly higher than that of the 1740/1720 mixed lubricant.

Of course, the above contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the embodiments of the present invention. The present invention is not limited to the above examples, and equal changes and improvements made by ordinary technicians in the technical field within the essential scope of the present invention should all fall within the scope of the patent coverage of the present invention.

Claims (9)

1. The cutting fluid for improving the dispersibility and reducing the foam type diamond wire silicon wafer is characterized in that: the composite material is prepared from the following raw materials in percentage by mass:

the balance of deionized water;

the dispersant is a polyethylene glycol derivative containing quaternary ammonium salt, and the number average molecular weight of the polyethylene glycol derivative is 500-700.

2. The silicon wafer cutting fluid for improving the dispersibility and reducing the foam type diamond wire according to claim 1, which is characterized in that: the lubricant is a mixed compound of trans-block polyether polyol 1740 and trans-block polyether polyol 1720 in a weight ratio of 1/2-2/1.

3. The cutting fluid for improving the dispersibility and reducing the foam type diamond wire silicon wafers according to claim 2 is characterized in that: the cloud point of a 1% aqueous solution of trans-block polyether polyol 1740 is 50. + -. 2 ℃ and the cloud point of a 1% aqueous solution of trans-block polyether polyol 1720 is 35. + -. 2 ℃.

4. The cutting fluid for improving the dispersity and reducing the foam type diamond wire silicon wafers according to claim 1 is characterized in that: the dispersant is an intermediate generated by ring-opening polymerization of N, N' -dimethylethanolamine as an initiator and ethylene oxide under the action of a catalyst, and is desalted by a magnesium silicate adsorbent and finally neutralized with acetic acid to generate the polyethylene glycol derivative containing the quaternary ammonium salt.

5. The silicon wafer cutting fluid for improving the dispersibility and reducing the foam type diamond wire according to claim 1, which is characterized in that: the penetrating agent is one or more of isomeric octanol polyoxyethylene ether, isomeric decanol polyoxyethylene ether and isomeric tridecanol polyoxyethylene ether.

6. The silicon wafer cutting fluid for improving the dispersibility and reducing the foam type diamond wire according to claim 1, which is characterized in that: the defoaming agent is one or more of polyoxypropylene ether, GPES type stearate polyoxyethylene polyoxypropylene glycerol ether and dodecene glycol polyether.

7. The silicon wafer cutting fluid for improving the dispersibility and reducing the foam type diamond wire according to claim 1, which is characterized in that: the chelating agent is one or more of disodium EDTA, tetrasodium EDTA, and disodium citrate.

8. The cutting fluid for improving the dispersity and reducing the foam type diamond wire silicon wafers according to claim 1 is characterized in that: the antioxidant is water-soluble antioxidant, and comprises one or more of vitamin C, tea polyphenols, and disodium stannous citrate.

9. The preparation method of the foam type diamond wire silicon wafer cutting fluid with improved dispersibility and reduced foam type according to any one of claims 1 to 8, which is characterized by comprising the following steps: the method comprises the following steps:

(1) Adding deionized water into a reaction kettle according to the formula proportion, and heating to 35-40 ℃ while stirring;

(2) Sequentially adding a lubricant, a dispersing agent, a penetrating agent, a defoaming agent, a chelating agent and an antioxidant into a reaction kettle, stirring for 1-2 h, and filtering to obtain the cutting fluid for improving the dispersibility and reducing the foam type diamond wire silicon wafer.