CN108559602B - A water-based diamond wire silicon wafer cutting fluid - Google Patents

Abstract

The invention belongs to the technical field of silicon crystal cutting in the photovoltaic industry, and particularly relates to a water-based diamond wire silicon wafer cutting fluid. The components of the water-based diamond wire silicon wafer cutting fluid comprise fatty acid methyl ester, polyethylene glycol 400 monolaurate, di-sec-octyl maleate sodium sulfonate, polyoxyethylene sorbitan monooleate, sodium xylene sulfonate, decyne glycol polyoxyethylene ether and deionized water.

Description

A water-based diamond wire silicon wafer cutting fluid

technical field

The invention belongs to the technical field of silicon crystal cutting in photovoltaic industry, and particularly relates to a water-based diamond wire silicon wafer cutting liquid.

Background technique

With the changes in global energy demand, clean and environmentally friendly energy has become a hot research topic. Solar energy is both primary energy and renewable energy. It is rich in resources and can be used free of charge without transportation and without any pollution to the environment. It has created a new form of life for human beings, enabling society and human beings to enter an era of saving energy and reducing pollution. Photovoltaic semiconductor wafers have emerged as the times require and have become the pillar industry of solar energy, and the demand for wafers has grown rapidly. Slicing is an important process in silicon wafer processing, and it is also one of the main processes that cause silicon wafer stress, surface and subsurface damage, and edge chipping. The wafer cutting yield directly determines the production capacity of the photovoltaic industry. The performance of the cutting fluid is one of the key factors affecting the efficiency and quality of silicon wafer cutting.

The current silicon wafer cutting process mainly uses free mortar cutting suspension and diamond wire cutting, while diamond sand wire cutting is a newer cutting process, which is still in its infancy in my country. This process mainly uses the diamond coated on the outer layer of the sand line to rub against the silicon wafer for cutting. The cutting liquid does not need to suspend the silicon carbide particles, nor does it need to have a high viscosity, and does not need to mix the silicon carbide blade material in the solution. Its cutting speed is 2 to 3 times that of steel wire in the mortar cutting process, and the sheet output rate is also higher than that of the mortar cutting method, and its water and electricity consumption is reduced by two-thirds compared with the mortar cutting technology, and the silicon powder produced after cutting can be completely Recycling, so the depreciation, labor and energy costs per unit of output will be greatly reduced, which can be described as energy saving and environmental protection.

Patent CN102321497A discloses a solar silicon wafer cutting fluid, including polyethylene glycol, surfactants, lubricants, penetrants and chelating agents, and also contains organic compounds with sulfur-oxygen double bonds. Although this patent has good performance, it belongs to the traditional free mortar cutting suspension, and this series of suspensions is currently in the elimination technology.

Patents 105695076A and 105713714A belong to the same series of products, and most of them use surfactants such as alkylphenol polyoxyethylene ether, which are prohibited by the state. In fact, although the use of styrene-butadiene rubber accelerates the agglomeration of silicon powder, the adhesion of large particles of silicon powder to the diamond wire also reduces the yield of silicon wafer cutting.

At present, the surface of the silicon wafer after being cut by the commercially available silicon wafer cutting fluid has a large TTV and has line marks. Since the silicon wafer will undergo brittle cracking or scratches during the cutting process, the roughness and warpage of the surface of the silicon wafer will be affected. There is an error in the total thickness of the silicon wafer.

The diamond wire has a short service life, and many silicon wafer cutting fluids use additives of poor quality, which are not conducive to cleaning after cutting, thus shortening the service life of the diamond wire.

During the silicon wafer cutting process, the silicon powder of the chips will release hydrogen due to the reaction with water due to the too fine particle size, and the long-term production accumulation will cause potential safety hazards.

Compared with the traditional mortar suspension cutting process and the diamond sand wire cutting process, the friction force generated by the friction between the diamond plated on the outer layer of the sand wire and the silicon wafer is much higher than that of the mortar suspension, resulting in an instantaneously stronger high temperature during cutting, cooling The effect is reduced and the sedimentation of silicon powder is not good, which leads to the existence of solid silicon fine powder that is not easy to clean on the surface of the cut silicon wafer, thereby reducing the smoothness of the product and the low yield.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is: on the premise that the traditional mortar suspension cutting liquid is eliminated, a cutting liquid for cutting silicon wafers with diamond sand wire is provided, which solves the problem of slow cutting speed, poor sedimentation of silicon powder and low yield of silicon wafers. technical issues.

In order to solve the above-mentioned technical problems, the technical solution adopted in the present invention is to provide a water-based diamond wire silicon wafer cutting fluid, the components of which include fatty acid methyl ester, polyethylene glycol 400 monolaurate, and disecondary maleate. Sodium octyl sulfonate, polyoxyethylene sorbitan monooleate, sodium xylene sulfonate, decynediol polyoxyethylene ether, and deionized water.

Specifically, the above water-based diamond wire silicon wafer cutting fluid includes the following components in parts by weight: 5-10 parts of fatty acid methyl ester, 8-15 parts of polyethylene glycol 400 monolaurate, maleic acid 5-10 parts of sodium di-secondary octyl sulfonate, 2-5 parts of polyoxyethylene sorbitan monooleate, 0.1-1 part of sodium xylene sulfonate, 1-5 parts of decynediol polyoxyethylene ether and Deionized water 60-80 parts.

Further, the water-based diamond wire silicon wafer cutting liquid includes the following components in parts by weight, preferably: 8 parts of fatty acid methyl ester, 10 parts of polyethylene glycol 400 monolaurate, and di-sec-octyl maleate 5 parts of sodium sulfonate, 4 parts of polyoxyethylene sorbitan monooleate, 0.5 parts of sodium xylene sulfonate, 2.5 parts of decynediol polyoxyethylene ether and 70 parts of deionized water.

Among them, fatty acid methyl ester has excellent anti-wear property and thermal stability. In the present invention, the anti-wear index is WS1.4≤300μm (60°C), which shows that the friction force can be significantly reduced under high temperature friction conditions, and it has good anti-friction resistance. Grinding lubrication performance. Polyethylene glycol 400 monolaurate has emulsifying, lubricating, defoaming, and solubilizing properties, especially it can tightly lock fatty acid methyl esters without delamination, ensure dehydration of fatty acid methyl esters, and promote the stability of the system. Sodium disec-octyl maleate sulfonate and polyoxyethylene sorbitan monooleate have strong wetting properties, can quickly penetrate into the contact surface of diamond wire and silicon wafer, and can lock other hydrophilic properties of the system. The water-lipophilic groups can be aligned on the surface of the solution, speed up the cutting speed and take away a lot of heat. In the present invention, sodium xylene sulfonate has the functions of sterilization, hydrotropy, homogenization, dispersion, etc., and reduces cloud point and viscosity, greatly improves the cooling effect of cutting fluid, and also sharpens emery in the present invention. , to improve cutting efficiency. The decynediol polyoxyethylene ether has a unique bimolecular structure, which is suitable for the anti-foaming wetting agent of the water-based system, and greatly improves the dynamic wetting ability of the system of the present invention to various silicon wafers and diamond wires. Static and dynamic surface tension Low, promotes flow and leveling, and reduces scratches on silicon wafers by silicon powder. And it can improve the settling speed of the silicon powder of the system, and quickly take away the silicon powder produced in the cutting process, which is the rapid solid-liquid separation of the silicon powder and the cutting fluid, ensuring that the performance of the system does not fluctuate for a long time.

The invention also provides a preparation method of the above water-based diamond wire silicon wafer cutting liquid: fatty acid methyl ester, polyethylene glycol 400 monolaurate, sodium disec-octyl maleate sulfonate, polyoxyethylene Sorbitan monooleate and decynediol polyoxyethylene ether are added to the stirring tank and stirred evenly, then deionized water is slowly added while stirring to obtain a transparent emulsion, and finally sodium xylene sulfonate is added and stirred evenly to obtain water-based diamond Line silicon wafer cutting fluid.

The beneficial effects of the present invention are as follows: the water-based diamond wire silicon wafer cutting fluid of the present invention has excellent lubrication, cooling and silicon powder sedimentation effects, and through the organic combination of various raw materials in the formula, the cutting speed of silicon wafers is fast, and the silicon wafers are good The rate is high, the silicon powder residue on the surface of the silicon wafer is small, and the diamond wire wear is small. In addition, the water-based diamond wire silicon wafer cutting fluid preparation method has simple process, easily controllable conditions, low cost, low equipment requirements, and is suitable for industrial production.

Detailed ways

Example 1

A water-based diamond wire silicon wafer cutting fluid, calculated in parts by weight as the following components: 8 parts of fatty acid methyl ester, 10 parts of polyethylene glycol 400 monolaurate, and di-sec-octyl maleate sulfonic acid 5 parts of sodium, 4 parts of polyoxyethylene sorbitan monooleate, 0.5 parts of sodium xylene sulfonate, 2.5 parts of decynediol polyoxyethylene ether and 70 parts of deionized water.

The preparation method of the water-based diamond wire silicon wafer cutting liquid in the present embodiment is:

Add fatty acid methyl ester, polyethylene glycol 400 monolaurate, sodium di-sec-octyl maleate sulfonate, polyoxyethylene sorbitan monooleate, and decynediol polyoxyethylene ether to the stirring mixture. The tank is stirred evenly, then deionized water is slowly added while stirring to obtain a translucent emulsion, and finally sodium xylene sulfonate is added and stirred evenly to obtain an aqueous diamond wire silicon wafer cutting solution.

Example 2

A water-based diamond wire silicon wafer cutting fluid, calculated in parts by weight as the following components:

10 parts of fatty acid methyl ester, 8 parts of polyethylene glycol 400 monolaurate, 5 parts of sodium di-sec-octyl maleate sulfonate, 5 parts of polyoxyethylene sorbitan monooleate, xylene sulfonic acid 1 part of sodium, 5 parts of decynediol polyoxyethylene ether and 66 parts of deionized water.

The preparation method of the water-based diamond wire silicon wafer cutting liquid in the present embodiment is:

Add fatty acid methyl ester, polyethylene glycol 400 monolaurate, sodium di-sec-octyl maleate sulfonate, polyoxyethylene sorbitan monooleate, and decynediol polyoxyethylene ether to the stirring mixture. The tank is stirred evenly, then deionized water is slowly added while stirring to obtain a translucent emulsion, and finally sodium xylene sulfonate is added and stirred evenly to obtain an aqueous diamond wire silicon wafer cutting solution.

Example 3

5 parts of fatty acid methyl ester, 15 parts of polyethylene glycol 400 monolaurate, 10 parts of sodium di-sec-octyl maleate sulfonate, 2 parts of polyoxyethylene sorbitan monooleate, xylene sulfonic acid 0.1 part of sodium, 1 part of decynediol polyoxyethylene ether and 66.9 parts of deionized water.

The preparation method of the water-based diamond wire silicon wafer cutting liquid in the present embodiment is:

Add fatty acid methyl ester, polyethylene glycol 400 monolaurate, sodium di-sec-octyl maleate sulfonate, polyoxyethylene sorbitan monooleate, and decynediol polyoxyethylene ether to the stirring mixture. The tank is stirred evenly, then deionized water is slowly added while stirring to obtain a translucent emulsion, and finally sodium xylene sulfonate is added and stirred evenly to obtain an aqueous diamond wire silicon wafer cutting solution.

After diluting the cutting fluids of the above-mentioned embodiments by 400 times with deionized water, the silicon rods of the same specification were cut by diamond sand wire. Meanwhile, the UDML200C solar wafer cutting fluid (mark A) imported from the United States was also diluted 400 times with deionized water. After doubling, the silicon rods of the same size were cut by diamond wire, and the traditional mortar suspension cutting was performed on the silicon rods of the same size by using the mortar suspension cutting fluid (marked B) produced by Liaoning Aoke Chemical Co., Ltd. The relevant experimental results are shown in Table 1:

Table 1, embodiment of the present invention and comparative example cutting data test table

From Table 1, it can be seen that the embodiments of the present invention are superior to the traditional mortar suspension cutting fluid in all aspects, and each performance index is equivalent to the imported diamond wire cutting fluid.

Finally, it should be noted that the above-mentioned embodiments are only the preferred technical solutions of the present invention, and should not be regarded as limitations of the present invention. The embodiments in this application and the features in the embodiments can be any combination with each other. The protection scope of the present invention shall take the technical solutions described in the claims, including the equivalent alternatives of the technical features in the technical solutions described in the claims, as the protection scope. That is, equivalent replacements and improvements within this scope are also within the protection scope of the present invention.

Claims (3)

1. a water-based diamond wire silicon wafer cutting liquid, is characterized in that: the component of described water-based diamond wire silicon wafer cutting liquid comprises fatty acid methyl ester, polyethylene glycol 400 monolaurate, maleic acid two Sodium sec-octyl sulfonate, polyoxyethylene sorbitan monooleate, sodium xylene sulfonate, decynediol polyoxyethylene ether and deionized water; The water-based diamond wire silicon wafer cutting liquid includes the following components in parts by weight: 5-10 parts of fatty acid methyl ester, 8-15 parts of polyethylene glycol 400 monolaurate, and two secondary maleic acid. 5-10 parts of sodium octyl sulfonate, 2-5 parts of polyoxyethylene sorbitan monooleate, 0.1-1 part of sodium xylene sulfonate, 1-5 parts of decynediol polyoxyethylene ether and deionized Water 60-80 parts. 2. The water-based diamond wire silicon wafer cutting liquid according to claim 1, wherein the water-based diamond wire silicon wafer cutting liquid comprises the following components in parts by weight: 8 parts of fatty acid methyl esters , 10 parts of polyethylene glycol 400 monolaurate, 5 parts of sodium di-sec-octyl maleate sulfonate, 4 parts of polyoxyethylene sorbitan monooleate, 0.5 parts of sodium xylene sulfonate, decyl 2.5 parts of acetylene glycol polyoxyethylene ether and 70 parts of deionized water. 3. the preparation method of water-based diamond wire silicon wafer cutting liquid as claimed in claim 1 or 2, is characterized in that: described preparation method is: fatty acid methyl ester, polyethylene glycol 400 monolaurate, maleic acid Sodium di-sec-octyl diacid sulfonate, polyoxyethylene sorbitan monooleate, and decynediol polyoxyethylene ether were added to the stirring tank and stirred evenly, and then deionized water was slowly added while stirring to obtain a transparent emulsion. Finally, sodium xylene sulfonate is added and stirred evenly to obtain the water-based diamond wire silicon wafer cutting solution.