WO2020071576A1 - Fluorine-containing grease for semiconductor equipment - Google Patents

Abstract

The present invention relates to a fluorine-containing grease for semiconductor equipment, and disclosed is a fluorine-containing grease for semiconductor equipment, at least comprising: 60-90 wt% of perfluoropolyether (PFPE)-M as a base oil; 10-40 wt% of polytetrafluoroethylene (PTFE) as a thickener; and 0.1-10 wt% of sulfurized bis(dibutylcarbamodithioato)di-μ-oxodioxodimolybdenum) as an additive.

Description

[Correction by Rule 26.11.2018] 불소 Glue containing fluorine for semiconductor equipment

The present invention relates to a fluorine-containing grease for semiconductor equipment. More specifically, fluorine-containing grease, an lubricant optimized for the characteristics of semiconductor equipment, has a short stroke distance due to the characteristics of semiconductor equipment and takes into account that the temperature rises rapidly when the equipment is loaded in a short time. It relates to a fluorine-containing grease for semiconductor equipment that can reduce and increase the central pumping performance in the case of mold equipment.

The manufacture and use of fluorine-containing greases as lubricants have been conventionally known. Fluorine-containing greases have been prepared by suspending polytetrafluoroethylene (PTFE) polymers in perfluorinated liquids such as perfluoropolyether (PFPE) (see USP 4472290).

In addition, the invention of fluorine grease disclosed in Korean Patent Publication No. 1998-080506 (published on November 25, 1998) has been disclosed.

The disclosed invention comprises: 15-50% by weight of a polytetrafluoroethylene or tetrafluoroethylene (hereinafter referred to as TFE) copolymer having predominantly or partially fluorine and other ethylenically unsaturated monomers; 30 to 84.5% by weight of a perfluoroether oil having a viscosity comprised between 20 and 4000 cst at 20 ° C; 0.5 to 10% by weight of a surfactant or dispersant having a perfluoropolyether or perfluoroalkyl chain; And 0 to 10% by weight of anti-corrosion and / or antiwear additives, wherein the (per) fluoropolymer particles based on the TFE or their totals have an average size smaller than microns, and are the same as above. It relates to a fluorine grease having a composition having a wear diameter value of at least 25% lower than that of a conventional fluorine grease having the same component of the product.

The disclosed invention may exhibit performance as a lubricant used in a general machine or the like, but when additives are used in semiconductor equipment using fatty acid oil, there are problems such as particle generation.

Accordingly, there is a need for an invention of a fluorine-containing grease that conforms to the characteristics of temperature rise in a short time and short stroke distance of semiconductor equipment, and can improve particle prevention and equipment contamination prevention.

The present invention is to solve the problems of the prior art, the object of the present invention is to meet the characteristics of the temperature rise in a short time and short stroke distance of the semiconductor equipment, it is possible to improve the prevention of particle contamination of the equipment and equipment prevention It provides a fluorine-containing grease for semiconductor equipment.

As a technical solution for achieving the object of the present invention, as a first aspect of the present invention, perfluoropolyether (perfluoropolyether: PFPE) 60% by mass to 90% by mass, polytetrafluoroethylene (polytetrafluoroethylene: PTFE ) 10% by mass to 40% by mass, sulfurized bis (dibutylcarmabodithioate) di-μ-oxodioxodiol-diol (sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum)) 0.1% by mass to 10% by mass A fluorine-containing grease for semiconductor equipment comprising at least%.

In a second aspect of the present invention, perfluoropolyether (perfluoropolyether: PFPE) 60% by mass to 90% by mass, polytetrafluoroethylene (polytetrafluoroethylene: PTFE) 10% by mass to 40% by mass, organic sulfurized bis (Dibutylcarmabodathioate) Di-μ-oxodioxodiol didenum (sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum)) 0.1% by mass to 10% by mass of fluorine-containing grease for semiconductor equipment is presented do.

In a third aspect of the present invention, perfluoropolyether (PFPE) 73 mass%, polytetrafluoroethylene (PTFE) 25 mass%, sulfurized bis (dibutyl carmathiothio) A fluorine-containing grease for semiconductor equipment comprising at least 2% by mass of di-μ-oxodioxodioldenum (sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum)) is presented.

In a fourth aspect of the present invention, perfluoropolyether (PFPE) 73 mass%, polytetrafluoroethylene (PTFE) 25 mass%, organic sulfurized bis (dibutyl carmathiothioate) ) Di-μ-oxodioxodiol fluorine-containing grease for semiconductor equipment is proposed which contains at least 2% by mass of sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum).

According to the present invention, it is possible to meet the characteristics of the temperature rise in a short time and a short stroke distance of the semiconductor equipment, improve the prevention of particle contamination of the equipment and the equipment, and consequently the life of the semiconductor equipment. It works.

As a preferred embodiment of the present invention, perfluoropolyether (perfluoropolyether: PFPE) 60% by mass to 90% by mass, polytetrafluoroethylene (polytetrafluoroethylene: PTFE) 10% by mass to 40% by mass, sulfurized bis ( A fluorine-containing grease for semiconductor equipment comprising at least 0.1% to 10% by mass of dibutyl-carmabothiothio) di-μ-oxodioxodioldiobium (sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum)) is presented. .

Hereinafter, embodiments of the present invention will be described in detail.

Semiconductor equipment is sensitive to the problem of particle and contamination due to the characteristics of the target product and the long service life of expensive equipment. It is the key to effectively reduce the wear caused by friction between parts of the equipment during operation, and it shows a lot of difference in the life of the equipment according to the performance of the grease, which is a lubricant for this.

Grease is composed of thickeners (solid powder), base oil (liquid) and additives (powder), and the degree of hardness or softness is adjusted according to the mixing ratio. Since grease is a mixture of the above three materials, it is indicated as a national grade (National Lubricants Grease Institute_Grade: NLGI_Grade) rather than a viscosity grade. The lead grade is determined by the depth at which the iron mass enters the grease for 1 minute by placing the grease in the container at room temperature (25 ° C) and placing the specified iron mass on the grease. Hard grease has a low level of depth into which the iron mass has entered the grease and soft grease has a high level of depth with which the iron mass has entered the grease. The leading grade is represented by 9 grades of "000, 00, 0, 1, 2, 3, 4, 5, 6", and the lower the grade, the softer the grease. The leading class "2" is known as the most commonly used grease.

The existing grease used in semiconductor equipment has also used the leading grade "2". However, it has been found that the temperature of the equipment rises sharply due to the short stroke time and the load applied in a short time in semiconductor equipment using the leading grade "2" grease.

In addition, the grease yields wear resistance through a four-ball test. It has been found through experiments that the wear resistance of grease influences the life of the semiconductor equipment, and the wear resistance of the grease used in the semiconductor equipment greatly depends on the lead grade, the type of base oil PFPE and the selection of additives.

In addition, the grease as a lubricant may be liquid wet grease and gel or solid dry grease. The fluorine-containing grease for semiconductor equipment of the present invention is dry grease due to the characteristics of the semiconductor equipment used. More specifically, it is a wet type lubrication, but the thickener contains the base oil PFPE, and it represents the intermediate form of the liquid and solid phases of a mechanism that repeats discharge and absorption. This state of property is called a non-Newtonian viscous fluid.

Hereinafter, the configuration of the fluorine-containing grease for semiconductor equipment of the present invention will be described in detail.

 <Thickener>

The thickener of the fluorine-containing grease for semiconductor equipment of the present invention uses polytetrafluoroethylene (PTFE).

The polytetrafluoroethylene (polytetrafluoroethylene: PTFE) is a material exhibiting very high chemical resistance, very good heat resistance, very low coefficient of friction, very low surface tension (non-adhesive), high coefficient of thermal expansion, low dielectric constant and flame retardancy Is known. However, the disadvantage is that it has a low strength.

<Base>

The base oil of the fluorine-containing grease for semiconductor equipment of the present invention uses perfluoropolyether (PFFPE).

The perfluoropolyether (PFPE) has excellent fluidity, little oxidation degradation and evaporation, maintains stable performance for a long time, and has low surface friction.

<Additive>

The additive of the fluorine-containing grease for semiconductor equipment of the present invention uses sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum). .

Sulfurized bis (dibutylcarmabodithioate) di-μ-oxodioxodioldinum (sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum)) is a dry grease for semiconductor equipment and mixed with fluorine-based materials. This is a stable material.

<Example 1>

The fluorine-containing grease for semiconductor equipment of the present invention is 60% by mass to 90% by mass of perfluoropolyether (PFPE) as a base oil, and 10% by mass to 40% by mass of polytetrafluoroethylene (PTFE) as a thickener. %, Sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum (sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum)) as an additive at least 0.1% to 10% by mass It is a composition.

<Example 2>

As another embodiment of the present invention, the fluorine-containing grease for semiconductor equipment, 73% by mass of perfluoropolyether (PFPE) as a base oil, 25% by mass of polytetrafluoroethylene (PTFE) as a thickener, additive It is a composition comprising at least 2% by mass of sulfurized bis (sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum) di-μ-oxodioxodimolybdenum.

<Example 3>

As another embodiment of the present invention, the fluorine-containing grease for semiconductor equipment is 60% by mass to 90% by mass of perfluoropolyether (PFPE) as a base oil, and polytetrafluoroethylene (PTFE) as a thickener. 10% by mass to 40% by mass, 0.1% by mass of organic sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum (di-carbodithioato) di-μ-oxodioxodimolybdenum) It is a structure containing at least 10% by mass.

<Example 4>

As another embodiment of the present invention, the fluorine-containing grease for semiconductor equipment, 73% by mass of perfluoropolyether (PFPE) as a base oil, 25% by mass of polytetrafluoroethylene (PTFE) as a thickener, It is a composition containing at least 2% by mass of organic sulfide bis (dibutylcarmabodithioate) di-μ-oxodioxodioldinum (sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum) as an additive.

The base oil of the existing fluorine-containing grease uses Fomblin ^R PFPE from Solvay, but among the "Y, M, W, and Z" types of Solvay Fomblin ^R PFPE, the medium and low-priced "Y" type is used. However, the "Y" type, which has a relatively low viscosity index (visibility index: an index of stable properties that does not spread at high temperatures and has good fluidity at low temperatures), is known to exhibit many disadvantages in terms of high temperature stability due to the characteristics of semiconductor devices when used in semiconductor equipment. , It is known to exhibit many disadvantages in the life of the lubricant, that is, durability.

The perfluoropolyether (PFPE), which is the base of the embodiments of the present invention, uses Fomblin ^R PFPE of Solvay, but of Fomblin ^R PFPE "Y, M, W, Z" type of Solvay " By using M "type, the high temperature stability of semiconductor equipment has been improved.

Comparison of the material properties of the "Y" type and the "M" type of Fomblin ^R PFPE of Solvay is shown in Table 1 below.

Fomblin PFPE type	Viscosity index	Surface friction	4 ball test
Y type (Y 45)	117	25	1.53
M type (M 30)	338	22	0.56

    In the above table, viscosity index (viscosity index: ASTM D2270), surface friction (ASTM D1331, 20 ° C (dynes / cm)), 4 ball test (ASTM D4172 B 75, 1hr, 1200RPM 40kg, average diameter (mm) It was found that the lower the value of), the better the performance as a lubricant.

It has been found that the M type perfluoropolyether (PFPE) has excellent stability at high temperature compared to the Y type, a thin lubricating film, long durability, strong pressure, and excellent lubricity.

The additive of the embodiments of the present invention has a direct relationship with the abrasion resistance of the semiconductor equipment as described above, so it can influence the life of the expensive semiconductor equipment. In addition, considering that the base oil and thickener fluorine-based material of the present invention is a stable material that is not mixed unless it is a fluorine-based system, sulfurized bis (dibutylcarmabothiothio) di-μ-oxodioxodiololidenum (sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum).

The sulfurized bis (dibutylcarmabodithioate) di-μ-oxodioxodiol-diol (sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum)) is known as molybdenum disulfide in Korean and is an inorganic lubricant. Molybdenum disulfide is used, and it shows simplicity as a dry lubricant, but inorganic molybdenum disulfide has the disadvantage of causing contamination of semiconductor equipment due to its black color and dusting problem.

In order to solve the above problem, the fluorine-containing grease for semiconductor equipment of the present invention was found to be optimized for semiconductor equipment when an organic molybdenum disulfide (yellow) was used as an additive. The organic-based molybdenum disulfide was confirmed through several experiments as being excellent in lubrication, as well as in a fluorine-based material with little heterogeneity, little equipment contamination, and optimized for wear resistance and extreme pressure environments.

The fluorine-containing grease for semiconductor equipment of the present invention is a base oil of M type perfluoropolyether (PFPE) first in a mixing container in a clean room manufacturing environment of 10,000 classes or less due to the characteristics used in semiconductor equipment. (Liquid), a polytetrafluoroethylene (PTFE) thickener (powder) and an organic molybdenum disulfide additive (powder) are added based on the composition ratios of the above-described examples, and then mixed for a period of time to pass through a gel state. It is manufactured to be manufactured by minimizing the oil separation between the thickener and the base oil by distributing the thickener at a constant rate through the first 3 mill rolling process and the second 3 mill rolling process. The manufacturing process is very simple and satisfies the requirements of ultra-low dust generation, which is the most important in the semiconductor manufacturing environment.

The fluorine-containing grease for semiconductor equipment of the present invention manufactured by the above process, when used in semiconductor equipment, forms a semi-permanent lubricating form that has a thin lubricating film thickness and strong lubricating strength through ion bonding with a metal surface.

In addition, as a leading grade of 1st grade, it has high sliding performance, excellent central pumping performance, high stability at high temperature, and excellent performance in equipment abrasion resistance. Table 2 below shows the official test results for fluorine-containing grease for semiconductor equipment of the present invention.

Test Items	unit	standard	Test result	Test Methods
Admixture degree (25 ℃)	1 / 10mm	310-340	330	KS M 2032
NLGI rating	-	One	One	-
Thickener	-	-	PTFE	-
Base oil viscosity (VG 40 ℃, 100 ℃)	cSt	-	161, 44.8	KS M 2014
Dropping point	℃	220 or more	none	KS M 2033
Copper plate corrosion (100 ℃ / 24h)	-	No color change	1a	KS M 2088
Evaporation amount (99 ℃ / 22h)	%	1.8 or less	0.11	KS M 2037
Stability (25 ℃)	1 / 10mm	340 or less	328	KS M 2051
Weaning degree (100 ℃ / 24h)	%	5.0 or less	0.08	KS M 2050
4 ball wear	mm	-	0.48	ASTM D2266

In addition, the comparison between the fluorine-containing grease for semiconductor equipment of the present invention and other products for semiconductor equipment is shown in Table 3 below.

	ASTM	KS M	Product A	Product B	Products of the invention
lead	ASTM D217		# One	#One	#One
Thickener	-	-	Li soap	Li soap	PTFE
Base oil type	Kinds	-	Phenyl Ether	Group 3	PFPE
VG 40 ℃	ASTM D445	KS M 2014	113.9	128	159
VG 100 ℃			13.91	18.45	45
Evaporation wt%	ASTM D972	KS M 2037	1.96	1.87	0.19
Reason also wt%	ASTM D1742	KS M 2050	3.4	4.6	0.13
Copper plate corrosion	ASTM D4048	KS M 2088	1a	1a	none
4 ball wear mm	ASTM D2266		0.59	1.85	0.56
4-ball extreme pressure kgf	ASTM D2596		160	127	800 or more (not measurable)
Vacuum pressure			no mark	no mark	1.4 * 10-8

As shown in Tables 2 and 3, the reason for the fluorine-containing grease for semiconductor equipment of the present invention (wt%) was 0.08 to 0.13, and it is preferable to keep it below 0.9. In addition, the 4-ball wear test value of the fluorine-containing grease for semiconductor equipment of the present invention was found to be 0.48 mm-0.56 mm, and preferably maintained at 0.8 mm or less.

The above-described embodiments of the present invention are only some of various embodiments of the present invention. As the base oil of the present invention, perfluoropolyether (PFPE), polytetrafluoroethylene (PTFE) as a thickener, and organic sulfurized bis (dibutylcarmathiothioate) di-μ- as additives It is natural that various embodiments included in the technical concept of fluorine-containing grease for semiconductor equipment including at least oxodioxodiol-denum (sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum)) fall within the protection scope of the present invention.

The present invention is a lubricant grease for semiconductor manufacturing equipment, which has a very high industrial application.

Claims (8)

1. 60% by mass to 90% by mass of perfluoropolyether (PFPE) as base oil, 10% to 40% by mass of polytetrafluoroethylene (PTFE) as a thickener, and sulfurized bis (dibutyl) as an additive Fluorine-containing grease for semiconductor equipment containing at least 0.1% to 10% by mass of carbonaceathioate) sulfurized bis (dibutylcarbamodithioatodi-μ-oxodioxodimolybdenum).
2. 73% by mass of perfluoropolyether (PFPE) as base oil, 25% by mass of polytetrafluoroethylene (PTFE) as thickener, and sulfurized bis (dithiocarmathiothioate) as additive Fluorine-containing grease for semiconductor equipment containing at least 2% by mass of μ-oxodioxodioldenum (sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum)).
3. 60% by mass to 90% by mass of perfluoropolyether (PFPE) as base oil, 10% by mass to 40% by mass of polytetrafluoroethylene (PTFE) as a thickener, and organic sulfurized bis (die) as an additive Fluorine-containing grease for semiconductor equipment containing at least 0.1% to 10% by mass of butylcarmabodithioate) sulfurized bis (dibutylcarbamodithioatodi-μ-oxodioxodimolybdenum).
4. 73% by mass of perfluoropolyether (PFPE) as base oil, 25% by mass of polytetrafluoroethylene (PTFE) as thickener, and organic sulfurized bis (dibutylcarmathiothio) as additive Fluorine-containing grease for semiconductor equipment containing at least 2% by mass of -μ-oxodioxodioldenum (sulfurized bis (dibutylcarbamodithioato) di-μ-oxodioxodimolybdenum)).
5. The method according to any one of claims 1 to 4,

   Fluorine-containing grease for semiconductor equipment, characterized in that the leading grade of grease is 1st grade.
6. The method according to any one of claims 1 to 4,

   Fluorine-containing grease for semiconductor equipment, wherein the viscosity of the base oil is VG 40 ° C (159-161), VG 100 ° C (44.8-45).
7. The method according to any one of claims 1 to 4,

   Fluorine-containing grease for semiconductor equipment, characterized in that the grease level (wt%) is less than 0.9.
8. The method according to any one of claims 1 to 4,

   Fluorine-containing grease for semiconductor equipment, characterized by less than 0.8mm as a result of 4 ball wear test of grease.