Cutting oil composition

Abstract

Disclosed is a cutting oil composition, which is vastly superior in view of layer separation, dispersibility, viscosity, ingot-cleaning time after sawing, and wafer warpage after sawing, compared to conventional cutting oil compositions, and which includes mineral oil that is highly hydrogenated, as represented by Chemical Formulas 1 to 3, bentonite clay as a thickener, and glycerol trioleate as a dispersant. A cutting method using the cutting oil composition is also provided.

Claims

1. A cutting oil composition, comprising a mixture of mineral oil represented by Chemical Formula 1, mineral oil represented by Chemical Formula 2 and mineral oil represented by Chemical Formula 3, wherein Formula 1 is R1-(CnH2n−4)a-R2, wherein Formula 2 is R3-(CnH2n−2)b-R4, wherein Formula 3 is R5-(CnH2n)c-R6, wherein n is 5 or 6, and R1, R2, R3, R4, R5 and R6 are each H or OH, and wherein a is 7 to 20 b is 39 to 52 and c is 39 to 41.

2. The cutting oil composition of claim 1, further comprising a thickener and a dispersant.

3. The cutting oil composition of claim 2, wherein the thickener is bentonite clay and the dispersant is glycerol trioleate.

4. The cutting oil composition of claim 3, comprising 65 to 93 wt % of the mixture of mineral oil, 0.7 to 3 wt % of the bentonite clay, and 5 to 35 wt % of the glycerol trioleate.

5. The cutting oil composition of claim 4, comprising 70 to 90 wt % of the mixture of mineral oil, 1 to 2 wt % of the bentonite clay, and 9 to 29 wt % of the glycerol trioleate.

Description

BEST MODE

(1) Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those typically understood by those skilled in the art to which the present invention belongs. Generally, the nomenclature used herein is well known in the art and is typical.

(2) As used herein, when any part is said to “include” any element, this does not mean that other elements are excluded, and such other elements may be further included unless otherwise specifically mentioned.

Examples

(3) In the following Examples and Comparative Examples carried out on the items A, B, C and D, evaluation was performed based on the following criteria.

(4) 1) Measurement of Viscosity:

(5) Viscosity was measured using a DV-II+ Pro model from Brookfield and Spindle No. 62 at 50 rpm. Here, a viscosity of 90 to 140 mPa.Math.s at 25° C. indicates appropriateness for a cutting oil composition.

(6) 2) Measurement of Layer Separation:

(7) Whether layer separation occurred was evaluated by mixing cutting oil with silicon carbide (SiC). Specifically, cutting oil and SiC were mixed at a weight ratio of 1:1 and allowed to stand at room temperature for 24 hr, after which whether layer separation occurred at the top of the liquid was observed with the naked eye and categorized according to whether or not layer separation occurred. Here, the absence of layer separation indicates appropriateness for a cutting oil composition.

(8) 3) Measurement of Dispersibility:

(9) Dispersibility was evaluated by mixing cutting oil with silicon carbide (SiC), and the extent of dispersion of SiC in cutting oil was observed with the naked eye and determined to be good or poor. The result evaluated to be good indicates appropriateness for a cutting oil composition.

(10) 4) Measurement of Wafer-Cleaning Time after Sawing:

(11) The wafer-cleaning time after sawing was evaluated by measuring the time taken to remove most of cutting oil and SiC from the wafer immersed in a cleaning solution after sawing. A result of 60 min or less is regarded as superior for a cutting oil composition.

(12) 5) Measurement of Wafer Warpage after Sawing:

(13) The wafer warpage after sawing was evaluated by measuring the extent of warping of the cleaned wafer using a meter. Here, the result of evaluation of wafer warpage of 10 μm or less after sawing is regarded as superior for a cutting oil composition.

MODE FOR INVENTION

A. Examples 1 to 3 and Comparative Examples 1 and 2: Evaluation of Numeric Values of a of Chemical Formula 1, b of Chemical Formula 2, and c of Chemical Formula 3

(14) In the cutting oil composition including mineral oil represented by Chemical Formulas 1 to 3 below, evaluation for determining the numeric values of a of Chemical Formula 1, b of Chemical Formula 2, and c of Chemical Formula 3 was performed. The results are shown in Table 1 below.
R1-(CnH2n-4)a-R2  [Chemical Formula 1]
R3-(CnH2n-2)b-R4  [Chemical Formula 2]
R5-(CnH2n)c-R6  [Chemical Formula 3]

(15) In Chemical Formulas 1 to 3, n is 5 or 6, and R1, R2, R3, R4, R5 and R6 are each H or OH.

(16) TABLE-US-00001 TABLE 1 Comparative Comparative Example 1 Example 2 Example 3 Example 1 Example 2 a 7 18 20 5 39 b 52 39 41 38 31 c 41 43 39 57 30 Mineral oil 90 90 90 90 90 content wt % Bentonite clay 1 1 1 1 1 content wt % Glycerol trioleate 9 9 9 9 9 content wt % Cutting No layer No layer No layer Layer No layer oil + SiC = 1:1 separation separation separation separation separation layer separation (3 mm) Dispersibility Good Good Good Poor Good Viscosity 90 100 120 70 180 (mPa .Math. s @25° C.) Wafer-cleaning  25 min  30 min  40 min   65 min   70 min time after sawing Wafer warpage 9.9 μm 7.5 μm 7.7 μm 13.8 μm 12.2 μm after sawing

(17) As is apparent from Table 1, based on the results of evaluation of layer separation, dispersibility, viscosity, wafer-cleaning time after sawing, and wafer warpage after sawing, Examples 1 to 3, in which a of Chemical Formula 1 is 7 to 20, b of Chemical Formula 2 is 39 to 52, and c of Chemical Formula 3 is 39 to 41, were vastly superior than Comparative Examples 1 and 2.

B. Examples 4 to 6 and Comparative Examples 3 and 4: Evaluation of Mineral Oil Content

(18) In the cutting oil composition including mineral oil represented by Chemical Formulas 1 to 3, the values of a of Chemical Formula 1, b of Chemical Formula 2, and c of Chemical Formula 3 were fixed, and evaluation for quantitatively determining the mineral oil content was performed. The results are shown in Table 2 below.

(19) TABLE-US-00002 TABLE 2 Comparative Comparative Example 4 Example 5 Example 6 Example 3 Example 4 a 18 18 18 18 18 b 39 39 39 39 39 c 43 43 43 43 43 Evaluated oil 90 70 80 60 99 content wt % Bentonite clay 1 1 1 1 1 content wt % Glycerol trioleate 9 29 19 39 0 content wt % Cutting No layer No layer No layer Layer Layer oil + SiC = 1:1 separation separation separation separation separation layer separation (2 mm) (5 mm) Dispersibility Good Good Good Good Fair Viscosity 100 132 115 158 88 (mPa .Math. s @25° C.)

(20) As is apparent from Table 2, based on the results of evaluation of layer separation, dispersibility and viscosity, Examples 1 to 3, using 70 to 90 wt % of mineral oil, were vastly superior than Comparative Examples 3 and 4.

C. Examples 7 and 8 and Comparative Examples 5 to 7: Evaluation of Bentonite Content

(21) In the cutting oil composition including mineral oil represented by Chemical Formulas 1 to 3, the values of a of Chemical Formula 1, b of Chemical Formula 2, and c of Chemical Formula 3 were fixed, and evaluation for quantitatively determining the bentonite content was performed. The results are shown in Table 3 below.

(22) TABLE-US-00003 TABLE 3 Comparative Comparative Comparative Example 7 Example 8 Example 5 Example 6 Example 7 A 18 18 18 18 18 B 39 39 39 39 39 C 43 43 43 43 43 Evaluated oil 90.0 89 91.0 90.5 86 content wt % Bentonite clay 1.0 2.0 0.0 0.5 5.0 content wt % Glycerol trioleate 9 9 9 9 9 content wt % Cutting No layer No layer Layer Layer No layer oil + SiC = 1:1 separation separation separation separation separation layer separation (7.5 mm) (2.0 mm) Dispersibility Good Good Poor Fair Good Viscosity 100 140 45 69 296 (mPa .Math. s @25° C.)

(23) As is apparent from Table 3, based on the results of evaluation of layer separation, dispersibility and viscosity, Examples 7 and 8, using 1 to 2 wt % of bentonite, were vastly superior than Comparative Examples 5 to 7.

D. Examples 9 to 11 and Comparative Examples 8 and 9: Evaluation of Glycerol Trioleate Content

(24) In the cutting oil composition including mineral oil represented by Chemical Formulas 1 to 3, the values of a of Chemical Formula 1, b of Chemical Formula 2, and c of Chemical Formula 3 were fixed, and evaluation for quantitatively determining the glycerol trioleate content was performed. The results are shown in Table 4 below.

(25) TABLE-US-00004 TABLE 4 Comparative Comparative Example 9 Example 10 Example 11 Example 8 Example 9 A 18 18 18 18 18 B 39 39 39 39 39 C 43 43 43 43 43 Evaluated oil 90.0 79.0 84.0 94.0 98.9 content wt % Bentonite clay 1.0 1.0 1.0 1.0 1.0 content wt % Glycerol trioleate 9.0 20.0 15.0 5.0 0.1 content wt % Cutting No layer No layer No layer No layer Layer oil + SiC = 1:1 separation separation separation separation separation layer separation (2.0 mm) Dispersibility Good Good Good Fair Fair Viscosity 100 119 108 89 74 (mPa .Math. s @25° C.)

(26) As is apparent from Table 4, based on the results of evaluation of layer separation, dispersibility and viscosity, Examples 9 to 11, using 9 to 20 wt % of glycerol trioleate, were vastly superior than Comparative Examples 8 and 9.

(27) Based on the above results, when using 70 to 90 wt % of mineral oil in which a of Chemical Formula 1 is 7 to 20, b of Chemical Formula 2 is 39 to 52 and c of Chemical Formula 3 is 39 to 41, 1 to 2 wt % of bentonite, and 9 to 20 wt % of glycerol trioleate, layer separation, dispersibility, viscosity, wafer-cleaning time after sawing, and wafer warpage after sawing were evaluated to be significantly superior.

(28) All simple modifications or variations of the present invention that may be easily performed by those skilled in the art are incorporated in the scope of the present invention.