TWI613188B - Water-soluble cutting fluid for fixed honing granule saw, cutting method using the same, and substrate for electronic material obtained therefrom - Google Patents

Abstract

The invention provides a water-soluble cutting fluid for a fixed abrasive grain wire saw with less foaming and high cutting performance, a cutting method for an ingot using the same, and an electronic material substrate obtained therefrom.

A water-soluble cutting fluid for a fixed abrasive grain wire saw, which contains (a) 2,4,7,9-tetramethyl-5-decyne-4,7-diol (2,4, 7,9-tetramethyl-5-decyne-4,7-diol) alkylene adduct. A cutting method of an ingot and a substrate for an electronic material obtained by the cutting method. The ingot cutting method uses the above-mentioned water-soluble cutting fluid for a fixed abrasive wire saw, and the ingot is cut by the fixed abrasive wire saw. A wafer as an electronic material substrate is obtained.

Description

Water-soluble cutting fluid for fixed abrasive grain wire saw, cutting method of ingot using the same, and substrate for electronic material obtained from the same

The present invention relates to a water-soluble cutting fluid for a fixed abrasive grain wire saw for cutting a silicon ingot, a cutting method for the ingot using the same, and an electronic material substrate obtained therefrom.

Previously, wafers of substrates for electronic materials were obtained by cutting with a band saw or a wire saw using free abrasive particles. However, cutting with free abrasive particles has the following problems: the slurry adheres to the cut wafer, the cleaning load in the subsequent steps is high, and it is not easy to use the liquid to free abrasive particles, sludge, and cutting Liquid separation and poor reusability.

In response to these problems, the development of fixed abrasive wire saws that use electroplating or resin adhesives to fix abrasive particles on the wire has the advantages of simplifying the cleaning step or improving the recyclability by separating the cutting fluid from the sediment. As a cutting fluid used when cutting a wafer that is a substrate for an electronic material using the fixed abrasive wire saw, water or a water-soluble cutting fluid such as those described in Patent Documents 1 and 2 has been proposed.

Patent Document 1: Japanese Patent Application Laid-Open No. 2003-82334

Patent Document 2: Japanese Patent Application Laid-Open No. 2009-57423

However, in recent years, in order to improve the quality and cutting speed, the linear speed has been gradually increased, and there is a problem that if a water-soluble cutting fluid as disclosed in Patent Documents 1 and 2 is used to cut an ingot that is a substrate for electronic materials, The water-soluble cutting fluid used will foam, and a good quality wafer cannot be obtained.

Therefore, the present invention provides a water-soluble cutting fluid for a fixed abrasive grain wire saw with low foaming and high cutting performance, a cutting method using the ingot, and a substrate for an electronic material obtained therefrom.

In order to achieve the above object, the present inventors have made repeated efforts, and as a result, found that by using (a) 2,4,7,9-tetramethyl-5-decyne-4,7-diol (2,4 , 7,9-tetramethyl-5-decyne-4,7-diol), a water-soluble cutting fluid of alkylene adducts, can be used to reduce foaming even when used to fix abrasive wire saws And cutting with high cutting performance, thereby completing the present invention. That is, the present invention relates to a water-soluble cutting fluid for a fixed abrasive wire saw, which is characterized by containing (a) 2,4,7,9-tetramethyl-5-decyne- Alkyl adduct of 4,7-diol.

(Where R represents the same or different carbon number of 1 to 4 alkylene groups, and m1 + m2 + n1 + n2 represents the total number of moles of alkylene adducts, which is an integer of 1 or more)

The present invention relates to a method for cutting an ingot and a substrate for an electronic material obtained by the method. The method for cutting an ingot is characterized in that the above-mentioned water-soluble cutting fluid for a fixed abrasive grain wire saw is used and fixed by The abrasive grain saw cuts the ingot to obtain a wafer as a substrate for electronic materials.

As described above, according to the present invention, it is possible to provide a water-soluble cutting fluid for a fixed abrasive grain wire saw with low foaming and high cutting performance, a cutting method using the ingot, and a substrate for an electronic material obtained therefrom.

The component (a) used in the water-soluble cutting fluid for a fixed abrasive grain wire saw of the present invention The fraction is an alkylene adduct of 2,4,7,9-tetramethyl-5-decyne-4,7-diol having a structure represented by the following chemical formula (1).

(Where R represents the same or different carbon number of 1 to 4 alkylene groups, and m1 + m2 + n1 + n2 represents the total number of moles of alkylene adducts, which is an integer of 1 or more)

In the above chemical formula (1), as the alkylene oxide added to 2,4,7,9-tetramethyl-5-decyne-4,7-diol, as long as it is a ring having 1 to 4 carbon atoms The oxyalkylene is sufficient, and specifically, an ethylene oxide monomer, or both ethylene oxide and propylene oxide are particularly preferable.

In addition, the added alkylene oxide is added by random polymerization. Therefore, if the 4 alkylene groups (-OR-) in the above chemical formula (1) are all alkylene groups having 1 to 4 carbon atoms, they may be the same. Or differently, it is preferred that the 4 alkylene groups are either ethylene monomers or both ethylene and propylene, and it is particularly preferred that the 4 alkylene groups are all ethylene.

In the above-mentioned chemical formula (1), the addition mole number of the alkylene adduct is 1 mole or more in total, preferably 1 to 20 moles, and more preferably 4 to 12 moles. In particular, when the added alkylene adduct is an ethylene oxide monomer, the ethylene oxide is preferably 4 to 12 moles, and more preferably 4 to 8 moles. Especially preferred is 4 to 6 moles. When the added alkylene adducts are ethylene oxide and propylene oxide, 4 to 8 moles of ethylene oxide and 2 to 4 moles of propylene oxide are preferred.

(a) The component may be used singly or in combination of two or more. The amount of the component (a) is preferably 0.01 to 5.0% by weight, and more preferably 0.05 to 2.0% by weight relative to the water-soluble cutting fluid. . If the amount of (a) is less than 0.01% by weight, the defoaming effect is small and the dynamic surface tension of the water-soluble cutting fluid is high. Therefore, it is difficult for the water-soluble cutting fluid to enter the processing site and deteriorate the cutting quality. 5.0% by weight, there is a case where it is difficult to obtain a formulation balance such as a defoaming effect with a water-soluble cutting fluid.

It is preferred that the water-soluble cutting fluid for a fixed abrasive grain wire saw of the present invention contains the components (b), (c), and (d) shown below in addition to the component (a). By containing the components (b), (c), and (d), the lubricity between the fixed abrasive grain line and the workpiece can be controlled, and the tool life of the fixed abrasive grain line can be improved.

In the present invention, the component (b) is preferably at least one of carboxylic acid, mercaptobenzothiazole, benzothiazolylthio acetic acid, and benzothiazolylthio propionic acid. More than that. The carboxylic acid may have one or more COOH groups, and examples thereof include caprylic acid, caproic acid, lauric acid, oleic acid, citric acid, maleic acid, fumaric acid, adipic acid, and Phthalic acid, malic acid, tartaric acid, dodecanedioic acid and sebacic acid. (b) A component may be used individually by 1 type, and may use 2 or more types together.

The component (c) is preferably at least one kind of amine, sodium hydroxide, and potassium hydroxide, and more preferably an amine. Examples of the amine include monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, dicyclohexylamine, and trimethylolpropane poly (propylene oxide) triamine. , N, N-bis (2hydroxyethyl) -N-cyclohexylamine and m-xylylenediamine (metaxylenediamine) alkylene adducts, etc. (c) A component may be used individually by 1 type, and may use 2 or more types together.

The component (b) and the component (c) may be contained in any ratio as long as they are both soluble in water. It is preferable that the component (c) is an amount that neutralizes the component (b) or more. The total of the component (b) and the component (c) is 5% by weight or less.

In addition, the component (d) is preferably at least one of a diol, a polyalkylene glycol, a glycol ether, a polyalkylene glycol ether, glycerol, and an alkylene adduct of glycerol. the above. The diol only needs to have two OH groups, and examples thereof include monoethylene glycol, diethylene glycol, triethylene glycol, monopropylene glycol, dipropylene glycol, tripropylene glycol, and hexanediol. As the polyalkylene dialkylene, Examples of the alcohol include polyethylene glycol, polypropylene glycol, a copolymer of polyoxyethylene polyoxypropylene, and a copolymer of polyoxyethylene polyoxybutylene. Examples of glycol ethers include diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, and diethylene glycol monohexyl ether. Examples of the polyoxyalkylene glycol ether include polyoxyethylene monomethyl ether, polyoxypropylene monomethyl ether, and monobutyl ether of a polyoxyethylene polyoxypropylene copolymer. Examples of the alkylene adducts of glycerol include ethylene adducts of glycerol, propylene adducts, and ethylene propylene copolymerization adducts. (d) A component may be used individually by 1 type, and may use 2 or more types together. The content of the component (d) is only required to be soluble in water, and is preferably 70% by weight or less.

In addition, the water-soluble cutting fluid for the fixed abrasive grain wire saw of the present invention may be added with a rust inhibitor, a preservative, a fragrance, a dye, or the like, as necessary.

By using the water-soluble cutting fluid for a fixed abrasive grain wire saw of the present invention and cutting an ingot by the fixed abrasive grain wire saw, a substrate for electronic materials with good quality can be obtained.

In the fixed abrasive wire saw used in the present invention, the wire used as the bus bar may be made of iron or stainless steel, and may also be copper-plated or platinum-plated. As abrasive particles fixed on the wire, Commercially available abrasive particles are used, preferably diamond and boron nitride. In order to fix the abrasive grains on a wire, it is preferable to use electroplating of a metal such as nickel or resin bonding using a resin.

The cutting machine used in the present invention is not particularly limited as long as it is a commercially available multi-wire saw processing machine, and it is preferably a multi-wire saw processing machine for fixed abrasive grain wire saws.

The ingot used in the present invention is not particularly limited as long as it is an ingot for manufacturing a substrate for electronic materials. For example, silicon, sapphire, crystal, quartz, silicon carbide, and lithium tantalate are preferably used. Ingots made of crystals such as gallium nitride, gallium arsenide, and gallium.

As described above, when a wafer as an electronic material copper substrate is cut from an ingot by a fixed abrasive wire saw, by using the water-soluble cutting fluid for a fixed abrasive wire saw of the present invention, foaming can be reduced, and Improves cutting performance.

Examples

Next, an example of the water-soluble cutting fluid for a fixed abrasive grain wire saw of the present invention will be described, but the present invention is not limited to this. First, according to the blending amounts of the components shown in Tables 1 and 2, these are mixed by a conventional method to obtain the water-soluble cutting fluid for fixed abrasive grain wire saws of Examples 1 to 9 and Comparative Example 1 The water-soluble cutting fluid for the fixed abrasive wire saw to Comparative Example 4.

(Foaming test)

Next, assuming foaming during cutting, 50 ml of the water-soluble cutting fluid for fixed abrasive wire saws of Examples 1 to 9 and the water-soluble cutting fluid for fixed abrasive wire saws of Comparative Examples 1 to 4 were added to In the 100ml graduated cylinder with a plug, shake it vigorously after plugging the plug, and check the initial foaming amount immediately after shaking and the defoaming time until foaming disappears. The results are shown in Table 3. In addition, the stability was determined by standing at 25 ° C for one week. ○: No separation or precipitation in 1 week, △: In 4 days Separation and precipitation occurred within 1 week, and ×: Separation and precipitation occurred within 4 days.

According to Table 3, the stability of the cutting fluid of Comparative Example 2 is poor. Comparative Example 3 And 4 of the cutting fluid foamed more, the defoaming time also exceeded 60 seconds. On the other hand, it can be seen that the water-soluble cutting fluid for the fixed abrasive grain wire saw of the present invention has less foaming and is relatively good. Furthermore, in Comparative Example 2 with poor stability, the separated (a) component adheres to the device and piping and causes contamination, or the cutting quality is deteriorated by removing the (a) component from the cutting fluid, making it difficult to use. Cutting fluid.

(Cutting test)

Next, using the water-soluble cutting fluid for fixed abrasive wire saws of Examples 1 to 9 and the water-soluble cutting fluid for fixed abrasive wire saws of Comparative Examples 1 to 4, the cutting tests were performed under the conditions shown in Table 4 to determine The bottom-most height (PV) of the profile of the sliced wafer. The results are shown in Table 5.

It can be seen from Table 5 that the cutting fluids of Comparative Examples 1 and 2 cannot cut ingots, and the cutting fluids of Comparative Examples 3 and 4 have large PV values and cannot form good cross sections. In contrast, it can be seen that the PV value of the water-soluble cutting fluid for the fixed abrasive grain wire saw in this embodiment is small, and the cutting performance is good.

Claims (4)

A water-soluble cutting fluid for a fixed abrasive grain wire saw, containing (a) 2,4,7,9-tetramethyl-5-decyne-4,7-diol (2,4) represented by the following chemical formula (1) , 7,9-tetramethyl-5-decyne-4,7-diol) alkylene adduct, (b) carboxylic acid, mercaptobenzothiazole, benzothiazolylthio acetic acid ) And at least one of benzothiazolylthio propionic acid, and (c) at least one of amine, sodium hydroxide, and potassium hydroxide, and the content of (a) is 0.01 ~ 5.0% by weight,

(Where, R represents the same or different carbon number of 1 to 4 alkylene groups, and m1 + m2 + n1 + n2 represents the total addition mole number of the alkylene adducts, which is an integer of 1 or more). For example, the water-soluble cutting fluid for fixed abrasive wire saws in the first scope of the patent application, wherein the total addition mole number of the alkylene adduct of (a) is 4-12 moles. For example, the water-soluble cutting fluid for fixed-grain abrasive wire saws for which the scope of patent application is item 1 or 2 further contains (d) glycol, polyalkylene glycol, glycol ether, and polyalkylene glycol. At least one or more of ether, glycerin, and an alkylene adduct of glycerol. A method for cutting ingots, using the fixing of any one of claims 1 to 3 The water-soluble cutting fluid for abrasive wire saws cuts an ingot by a fixed abrasive wire saw to obtain a substrate for electronic materials.