KR20020047702A - Antistatic adhesives and manufacturing method of the same - Google Patents

Abstract

PURPOSE: Provided are an antistatic adhesive containing a quaternary ammonium salt which has improved antistatic function and does not leave a residue when being detached, and a method for preparing the same. CONSTITUTION: The composition comprises a quaternary ammonium salt of formula 1. In the formula 1, £A| represents -NH-(CH2)6-NH-, R1 represents hydrogen, an acryl group or methacryl group, R2 represents hydrogen, a methyl group or an ethyl group, R3 represents hydrogen or methyl group, X represents CH3OSO3, CH3CH2OSO3, CCl3COO, CF3COO, CH3C6H5SO3, H2PO4, HCl, n is an integer of 2-12. The compound of formula 1 has a molecular weight of 500 or more. The composition is prepared by the steps of (i) reacting a photocurable, polyfunctional monomer having at least two carbon-carbon double bonds in molecule with nucleophilic primary or secondary amine compound to synthesize a photocurable tertiary amine, and treating the tertiary amine with a suitable acid to synthesize a quaternary amine, and (ii) reacting the quaternary amine with isocyanurate urethane prepolymer having mono-functional or polyfunctional group at ends thereof to synthesize an antistatic low-molecular weight polymer having a new urethane bond.

Description

Antistatic adhesive and its manufacturing method {Antistatic adhesives and manufacturing method of the same}

The present invention relates to an antistatic adhesive, and more particularly to an adhesive having an excellent antistatic function and leaving no residue when the adhesive is squeezed out.

In the late 20th and 21st centuries, as the industrial structure changed to the information technology industry, each electronic component tended to be miniaturized, and accordingly, the miniaturization process that requires the production of many circuits in a small area IC chip has been developed. With the miniaturization of circuits, many efforts have been made to reduce the production efficiency caused by pollutants such as dust, which causes pollution.

Recently, due to advances in the semiconductor manufacturing technology with the development of the information industry, efforts have been made to prevent contamination due to an increase in the degree of integration of circuits, in which many circuit elements must be put in one small chip.

In order to prevent such contamination, a clean class of about 1,000 classes is used, but countermeasures against static electricity generated in the semiconductor manufacturing process are insufficient. There was no way to remove the static electricity from the labeling process.

In general, semiconductor devices that exhibit sensitive reactions from static electricity are defined as so-called ESD sensitive items and require attention from production to after-care. For example, the static voltage generated from a label using a solvent type or an emulsion adhesive is 100,000 V to thousands of V, which is a constant voltage of at least 50 V since it becomes 0 <sensitivity <1,000 V or more, which is a level 1 level of the electric discharge sensitive items. High-density semiconductor devices that must be maintained are subject to various damages.

Among the adhesive tapes used in the semiconductor manufacturing process, tapes used for semi-fixing include wafer adhesive dicing, polishing, weak adhesive tapes used in electronic component manufacturing processes, UV curable tapes, and heat peeling tapes. In the semiconductor process, many waxes are used to fix wafers. However, since organic solvents used to clean and remove waxes after processing adversely affect the environment, in recent years, the use of organic solvent cleaners has been avoided and the use of adhesive tapes has been expanded. It is becoming.

In addition, wafers of semiconductor materials such as silicon and gallium-arsenide, in which integrated circuits are made, have a diameter of about 200 mm, and in the production process of IC chips, these large wafers are fixed to an adhesive tape called dicing tape. After a small cut, they are released from the dicing tape and released to the lead frame. In other words, the dicing tape among the adhesive products used in the semiconductor manufacturing process is used for fixing and transporting the wafer in the sawing process of cutting the wafer on which the integrated circuit is formed into a plurality of IC chips with a diamond saw. have.

The dicing tape used in the wafer manufacturing technology should have strong adhesive force with the semiconductor wafer in the process of cutting the wafer into IC chips, and the adhesive force with the IC chip should be reduced in the step of removing the small IC. The silver should have a double-sided property that should be removed immediately from the dicing tape without leaving any residue of the adhesive. In addition, since these wafers are made of fine electronic circuits, the static electricity generated from peeling when peeled off should have a very weak static electricity of less than 50 to 100 V, and the surface resistance of the adhesive to bring out static electricity of less than 50 V when peeled off. This at least 10⁷Ω / cm 3. In other words, these dicing tapes not only have a simple adhesive function, but also have no residue on the substrate when they are attached and removed. No removal residue and antistatic functions are essential.

However, conventional dicing tapes do not have sufficient antistatic function, which leads to chip removal. When picking up Many tribocharges occur, causing chip defects and failing to maintain adhesion, or after adhesion, residues on the back of the chip cause many defects during the process.

On the other hand, in the chip manufacturing process, the charging of the wafer is a cause, and a lot of defects occur during the manufacturing process, and when the wafer support is an insulator, it causes a charge blocking. In addition, charging of a manufacturing apparatus, various insulators, and a conveying container also causes a defect in the manufacturing process.

Generally, the charged surface adheres to particles charged with the opposite polarity to that of the charge. When the wafer is charged, the aerosol particles floating in the air easily adhere to the charged surface. Such adhesion of dust causes a failure such as a failure of the device or a decrease in the internal pressure. The charging of the wafer also occurs in ultrapure water cleaning, dicing, and the like. In ultrapure water cleaning, the amount of charge increases as the resistance value of water increases.

Therefore, in order to solve this problem, a lot of efforts have been made to maintain an antistatic effect on the adhesive component, a method of adding a material having a conductive component such as electrically conductive metal powder or carbon particles to the general adhesive formulation, electrostatic A method of adding an ionic substance in order to reduce the occurrence of, a method of using an antistatic tape and an alkaline earth metal salt made by applying a general adhesive to a metal-deposited film, and the like have been disclosed.

However, these techniques have their own characteristics, but there are limitations to using adhesives in emulsions and are often not applicable to the actual process of making dicing tapes. In addition, the characteristic of the dicing tape is not only an antistatic function, but also a residue of the adhesive when peeling off the cut chip should not remain on the back of the chip, but a general adhesive could not be used as a dicing tape.

The present inventors have conducted a number of studies to solve the problems of the prior art as a result of the synthesis of an antistatic oligomer containing a pressure-sensitive adhesive and a UV curable photocurable quaternary ammonium salt, and the The present invention has been completed by discovering that an antistatic pressure sensitive adhesive having an excellent antistatic function and residue are not formed, and having a surface resistance of 10 ⁷ Ω / cm 2 or less.

It is therefore an object of the present invention to provide an antistatic oligomer containing a quaternary ammonium salt that has excellent antistatic function and does not leave a residue when the adhesive is squeezed, an antistatic adhesive containing the same, and a method for producing the same.

In order to achieve the above object, the present invention provides an antistatic oligomer containing a quaternary ammonium salt represented by the following formula (I).

(Wherein

,

,

Is,

R ₁ is hydrogen, acrylic or methacryl group, R ₂ is hydrogen, methyl, or ethyl group, R ₃ is hydrogen or methyl group, X is CH ₃ OSO ₃ , CH ₃ CH ₂ OSO ₃ , CCl ₃ COO, CF ₃ COO , CH ₃ C ₆ H ₅ SO ₃ , H ₂ PO ₄ , HCl, n is an integer from 2-12)

The oligomer is obtained by synthesizing a photocurable antistatic monomer in a first step, and then a photocurable oligomer having a molecular weight of 500 or more in a second step.

The present invention also provides an antistatic adhesive containing an antistatic oligomer, an acrylic pressure sensitive adhesive, a hydroxypropyl acrylate (HPA) and a photoinitiator containing a quaternary ammonium salt represented by the above formula (I).

According to the present invention, the prepolymer can be photocured to form a three-dimensional network, thereby reducing the adhesive component of the adhesive and also solving the problem of the residue of the adhesive.

The photocurable antistatic oligomer containing the quaternary ammonium salt of the present invention is represented by the following general formula (I).

(Wherein

,

,

Is,

R ₁ is hydrogen, acrylic or methacryl group, R ₂ is hydrogen, methyl, or ethyl group, R ₃ is hydrogen or methyl group, X is CH ₃ OSO ₃ , CH ₃ CH ₂ OSO ₃ , CCl ₃ COO, CF ₃ COO , CH ₃ C ₆ H ₅ SO ₃ , H ₂ PO ₄ , HCl, n is an integer from 2-12)

The oligomer for photocurable antistatic adhesive of Formula I is prepared in the following steps.

In order to synthesize an antistatic monomer in the first step, a photocurable polyfunctional low molecular weight monomer and a nucleophilic primary or secondary amine compound are reacted to synthesize a photocurable tertiary amine, and then a quaternary ammonium salt is synthesized using a suitable acid. do.

Here, as the photocurable multifunctional low molecular weight monomer, a compound having two or more at least two carbon-carbon double bonds in a molecule is used, for example, trimethylolpropane triacrylate, tetramethyl Tetramethylolmethane tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxy pentaacrylate, dipentaerythritol hexaacrylate (dipentaerythritol hexaacrylate) ), 1,4-butylene glycol diacrylate (1,4-butylenegylcol diacrylate), polyethylene glycol diacrylate (polyethyleneglycol diacrylate) and the like.

The nucleophilic primary or secondary amine compound is a primary or secondary amine containing at least one or more hydroxy groups in the alkyl chain, for example, mono having one or two or more hydroxyl groups in the alkyl chain of 2 to 12 carbon atoms Ethanolamine, monopropanolamine, monobutanolamine, monopentanolamine, monohexanolamine, monoheptanolamine, monooctanolamine, monononanolamine, monodecanolamine, monoundecanolamine, monododecanol Primary amines such as amines or methyl or ethyl ethanolamine, methyl or ethyl propanolamine, methyl or ethyl butanolamine, methyl or ethyl pentanolamine, methyl or ethyl hexanolamine, methyl or ethyl heptanolamine, methyl or ethyl octane Secondary amines such as olamine, methyl or ethyl nonanolamine, methyl or ethyl decanolamine, methyl or ethyl undecanolamine, methyl or ethyl dodecanolamine And the like, or diethanolamine, di-propanol amine, di-butanol amine.

The reaction of the photocurable polyfunctional low molecular weight monomer and the primary or secondary amine which is a nucleophilic compound is carried out at 60 ° C. or lower.

As the acid, an inorganic acid, an organic acid, methyl sulfate, ethyl sulfate, or the like can be used. In addition, examples of the inorganic acid include HCl, HF, HBr, HI, H ₂ SO ₄ , H ₃ PO ₄ , and the like, and organic acids include p-toluenesulfonic acid, monochloroacetic acid, dichloroacetic acid and trichloroacetic acid. , Trifluoroacetic acid, trifluoromethanesulfonic acid, and the like, but the present invention is not limited thereto.

In the second step, the quaternary ammonium salt obtained in the first step and an isocyanurate urethane prepolymer having a mono- or polyfunctional group at the terminal, for example, 2,4-tolylene diisocyanate (2, 4-tolylene diisocyanate, diphenylmethane 4,4'-diisocyanate, 2,6-toluylene diisocyanate, 1,3-xylene diisocyanate Isocyanate (1,3-xylene diisocyante), 1,4-xylene diisocyante, diphenylmethane 2,4-diisocyanate, 3-methyldiphenyl 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexyl-methane-4,4'- diisocyanate (dicyclohexyl-methane 4,4'- diisocyante, isocyanuric trimmer Reactions with isocyanates such as ate trimer), etc., result in the synthesis of oligomers with photocurable antistatic functions with new urethane bonds.

Since the antistatic oligomer of the present invention synthesized as described above has a high viscosity, it may be used by diluting about 10 to 30% by weight with a photocurable diluent, wherein the diluent isooctyl acrylate, 4- 4-methyl-2-pentylacrylate, 2-methyl butylacrylate, isoamyl acrylate, sec-butyl acrylate , n-butyl acrylate (n-butylacrylate), 2-ethylhexy acrylate (2-ethylhexy acrylate) or methacrylate equivalent (methacrylate) and the like can be used. In addition, a polar substance having a hydroxy group at the terminal and having an acrylic or methacryl functional group may be used, for example, 2-hydroxyethyl acrylate or methacrylate, hydroxypropyl acrylate, caprolactam modified ethyl acrylate, or the like. Can be mentioned. It is also possible to dilute acrylates or methacrylates such as t-butyl acrylate, vinyl acetate or the like with a glass transition temperature greater than -20 ° C. into one or a mixture.

The photocurable antistatic oligomer of the formula (I) obtained as described above may obtain an anticonductive adhesive of the present invention by mixing an acrylic adhesive, hydroxypropyl acrylate and a photoinitiator.

The photoinitiator is used to be curable to UV, for example, isopropyl benzoin ether, isobutyl benzoin ether, benzopheneone, mycolide ketone ( Michler's ketone, dichlorothioxantone, dodecylthioxantone, dimethylthioxantone, acetophenone diethyl ketal, benzyldimethyl ketal, alpha-hydride Α-hydroxycyclohexyl phenylketone, 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexyl phenylketone 1-hydroxy cyclohexyl phenyl ketone). The photoinitiator may be used alone or in combination of 1 to 5% by weight.

Hereinafter, a method of preparing an antistatic adhesive of the present invention having excellent antistatic function and no residue will be described in more detail with reference to Examples.

Example 1

250g ethyl acetate, 50g n-butylacrylate, 50g n-hexylacrylate, 10g 2-hydroxyacrylate, 5g in a 2L glass reactor equipped with a strong stirrer, thermometer, dropping funnel, condenser and jacket Glycidyl methacrylate, 5 g 5-carboxypentyl acrylate and 1 g azobisisobutyronitrile are added. The polymer polymerization is carried out in a nitrogen atmosphere at 60 ° C. for 4 hours, and further reacted at 80 ° C. for 2 hours to obtain an acrylate adhesive.

Example 2

352 g of pentaerythritol tetraacrylate is placed in a 2 L glass reactor equipped with a strong stirrer, thermometer, dropping funnel, condenser and jacket, and 75 g of N-methylethanolamine is slowly dropped through the dropping funnel so that the reaction temperature does not exceed 50 ° C. Stir while stirring. After the dropwise addition is completed, the reaction temperature is maintained at 60 ° C. for 1 hour while stirring with a strong stirrer. Lower the temperature to 20 ℃ and dilute 50 g of isooctyl acrylate and slowly drop 116 g of trifluoroacetic acid to form a quaternary ammonium salt. At this time, since the reaction solution gels when the temperature exceeds 50 ° C., the temperature does not exceed 50 ° C. or more.

Example 3

When the synthesis of the quaternary ammonium salt, an antistatic monomer in Example 2, was completed, 100 g of hexamethylene diisocyanate and 100 g of ethyl acetate were slowly added dropwise to the reactor through a dropping funnel, and stirred with a strong stirrer while keeping the temperature not higher than 50 ° C give. Stir at least 3 hours to complete the reaction to obtain an antistatic oligomer.

Example 4

When the synthesis of the quaternary ammonium salt, an antistatic monomer in Example 2, was completed, 220 g of crotonate-HX (trade name of Polyurethane Co., Ltd., Japan) and 100 g of ethyl acetate were added dropwise through the reactor to the reactor. Slowly add dropwise and stir with a strong stirrer while keeping the temperature no higher than 50 ℃. Stir at least 3 hours to complete the reaction to obtain an antistatic oligomer.

Example 5

When the synthesis of the quaternary ammonium salt, an antistatic monomer in Example 2, was completed, 135 g of isophorone diisocyanate (Aldrich, Germany) and 100 g of ethyl acetate were slowly added dropwise through a funnel and the temperature was decreased. Stir with a strong stirrer while not exceeding 50 ° C. Stir at least 3 hours to complete the reaction to obtain an antistatic oligomer.

Examples 6-17

The antistatic oligomer, photoinitiator and hydroxypropyl acrylate (HPA) made in Examples 3 to 5 were combined with 100 parts of the acrylate adhesive solid component obtained in Example 1, in the amounts and components shown in Table 1 below. Stir at 50 ° C. for 2 hours. Filtration was carried out using a 50 micron filter bag to obtain an antistatic pressure sensitive adhesive. Table 1 summarizes the components and contents of each example.

Example 18

The acrylate adhesive prepared in Example 1 was applied to a 80-micron-thick polypropylene film substrate with a # 7 Meyer bar to be 10 microns thick, and then dried for 3 minutes with hot air at 80 ° C.

The pressure-sensitive adhesive coating, surface resistance and residue of the antistatic pressure sensitive adhesive obtained in Examples 6 to 18 were measured by the following method, and the results are shown in Table 2. In addition, photographs showing SEM results are shown in Tables 3 to 6.

Adhesive coating

The pressure-sensitive adhesive obtained in Examples 6 to 18 was applied directly to a 80-micron-thick polypropylene film substrate so as to be 10 microns thick, and dried for 3 minutes with hot air at 80 ° C, followed by a high-pressure mercury UV lamp (80 W / cm, irradiation interval 10 cm) for 3 seconds. The adhesive sheet thus prepared was applied to a clean glass surface having a thickness of 0.6 mm and 7 cm x 7 cm with a virtual silicon wafer, and the adhesive force between the glass plate and the adhesive sheet was measured by the Korean Industrial Standard KS A 1107 or JIS-Z-0237 method (180 °). Adhesion was measured by a peeling method, a peeling speed of 300 mm / min, a sample size of 25 mm × 25 mm, 23 ° C., 65% RH).

Measurement of surface resistance

The pressure-sensitive adhesive obtained in Examples 6 to 18 was applied directly to a 80-micron-thick polypropylene film substrate so as to be 10 microns thick, and dried for 3 minutes with hot air at 80 ° C, followed by a high-pressure mercury UV lamp (80 W / cm and an irradiation interval of 10 cm), the surface resistance value (Ω / cm 2) after 1 minute was measured by the ASTM-D257 method under a condition of 55% of humidity and an applied voltage of 500 V by using an ultra-insulating resistance meter.

Measurement of residue

The pressure-sensitive adhesive obtained in Examples 6 to 18 was applied directly to a 80-micron-thick polypropylene film substrate so as to be 10 microns thick, and dried for 3 minutes with hot air at 80 ° C, followed by a high-pressure mercury UV lamp (80 W / 3 cm x 3 cm glass plate was attached to the center of the adhesive sheet, held for 24 hours under a load of 10 kg, and the adhesive sheet was peeled off. After depositing with gold using a SEM (Scanning Electron Microscope, Model: Jeol JSM-5410LV) the surface was observed at 10,000 magnification.

SEM results in the table are shown as follows.

When you see more than 50 residues on the photo ×

When you see 50 or less residues on the picture △

When there is no residue on the picture ◎

Residual degree: X

Residual degree: X

Residual degree: △

Residual degree: ◎

As described above, the antistatic oligomer comprising the quaternary ammonium salt according to the present invention and the antistatic adhesive obtained by the combination thereof has an excellent antistatic function and forms an adhesive surface with no residue, and the surface resistance is 10 ⁷ Ω / cm 2 or less can be obtained.

Claims (14)

An antistatic oligomer containing a quaternary ammonium salt represented by the following formula (I). (Wherein , , Is, R ₁ is hydrogen, acrylic or methacryl group, R ₂ is hydrogen, methyl, or ethyl group, R ₃ is hydrogen or methyl group, X is CH ₃ OSO ₃ , CH ₃ CH ₂ OSO ₃ , CCl ₃ COO, CF ₃ COO , CH ₃ C ₆ H ₅ SO ₃ , H ₂ PO ₄ , HCl, n is an integer from 2-12) The antistatic oligomer according to claim 1, wherein the molecular weight of Formula 1 is 500 or more. After reacting a photocurable polyfunctional low molecular weight monomer having at least two carbon-carbon double bonds in a molecule with a nucleophilic primary or secondary amine compound and synthesizing it into a photocurable tertiary amine, 4 Synthesizing a quaternary ammonium salt; And Reacting the quaternary ammonium salt with an isocyanurate urethane prepolymer having a mono- or polyfunctional group at its end to synthesize an antistatic oligomer having a new urethane bond. The method of claim 3, wherein the photocurable multifunctional low molecular weight monomer is trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxy pentaacrylate, Method for producing an antistatic oligomer, characterized in that selected from dipentaerythritol hexaacrylate, 1,4-butylene glycol diacrylate, polyethylene glycol diacrylate The method of claim 3, wherein the nucleophilic primary or secondary amine compound is a primary or secondary amine or diethanolamine, dipropanolamine, dibutanolamine containing at least one or more hydroxy groups in an alkyl chain of 2 to 12 carbon atoms Method for producing an antistatic oligomer, characterized in that. The method of claim 5, wherein the primary amine is monoethanolamine, monopropanolamine, monobutanolamine, monopentanolamine, monohexanolamine, monoheptanolamine, monooctanolamine, monononanolamine, monodecane Method for producing an antistatic oligomer, characterized in that selected from olamine, monoundecanolamine, monododecanolamine. The method of claim 5, wherein the secondary amine is methyl or ethyl ethanolamine, methyl or ethyl propanolamine, methyl or ethyl butanolamine, methyl or ethyl pentanolamine, methyl or ethyl hexanolamine, methyl or ethyl heptanolamine, A method for producing an antistatic oligomer, characterized in that it is selected from methyl or ethyl octanolamine, methyl or ethyl nonanolamine, methyl or ethyl decanolamine, methyl or ethyl undecanolamine, methyl or ethyl dodecanolamine. 4. The method for producing an antistatic oligomer according to claim 3, wherein the photocurable polyfunctional low molecular weight monomer and the nucleophilic primary or secondary amine compound are reacted at 60 ° C or lower. The method of claim 3, wherein the acid is HCl, HF, HBr, HI, H ₂ SO ₄ , H ₃ PO ₄ Inorganic acid, p-toluenesulfonic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, tri A method for producing an antistatic oligomer, characterized in that it is selected from organic acids, methyl sulfate or ethyl sulfate of fluoromethanesulfonic acid. 4. The isocyanurate urethane prepolymer of claim 3 wherein the isocyanurate urethane prepolymer is 2,4-tolylene diisocyanate, diphenylmethane 4,4'-diisocyanate, 2,6-toluylene diisocyanate, 1,3-xylene di Isocyanate, 1,4-xylene diisocyanate, diphenylmethane 2,4-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexyl-methane-4,4 ' -Isocyanate, isocyanurate trimer, characterized in that the method for producing an antistatic oligomer. An antistatic pressure sensitive adhesive containing an antistatic oligomer containing a quaternary ammonium salt represented by the formula (I), an acrylic pressure sensitive adhesive, hydroxypropyl acrylate and a photoinitiator that is curable to UV. 12. The method of claim 11, wherein the photoinitiator is isopropylbenzoin ether, isobutylbenzoin ether, benzopheneone, mycules ketone, dichlorothiosanthone, dodecylthiosanthone, dimethylthiosanthone, acetophenonedi One or more selected from ethyl ketal, benzyldimethyl ketal, alpha-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropane-one, and 1-hydroxycyclohexyl phenyl ketone Antistatic pressure-sensitive adhesive, characterized in that it contains. 12. The antistatic pressure sensitive adhesive according to claim 11, wherein the content of the photoinitiator is 1 to 5% by weight. 12. The antistatic pressure sensitive adhesive according to claim 11, wherein the content of the antistatic oligomer is 30 to 60 denier relative to the total.