CN102026807A - Method for protection of surface of material to be processed, and temporary fixing method - Google Patents

Abstract

The present invention provides a surface protection method in which a protective film does not come off even when processing such as cutting is performed. The method for protecting the surface of a workpiece by laminating a protective film on the surface of the workpiece is characterized in that it includes the following steps: a lamination step of laminating a protective film made of a cured body on the surface of the workpiece, the cured body Formed from a curable composition containing (A) polyfunctional (meth)acrylate, (B) monofunctional (meth)acrylate, and (C) photopolymerization initiator; A heating step of performing heat treatment; and a processing step of processing a workpiece after the heating step. Moreover, it is preferable that the said protective film contains (D) resin which has a cyclopentadiene skeleton.

Description

Surface protection method and temporary fixing method of workpiece

technical field

The present invention relates to a surface protection method and a temporary fixing method of the workpiece when processing various materials. More specifically, when the present invention proposes to process optical members, semiconductor wafers, etc., a protective film (hereinafter also sometimes referred to as a cured body) formed by a curable composition is provided on the surface of the workpiece to protect the surface of the workpiece. The method of protecting the surface of the workpiece for the purpose of preventing the processed part from adhesion and damage of foreign matter during processing. In addition, the present invention also proposes a method for temporarily fixing a workpiece, which is characterized in that, by bonding the workpiece to a base material, after the workpiece is processed, the bonded part is immersed in warm water, and the above-mentioned protective film Take it off to recover the workpiece.

Background technique

In the processing of metal plates, molds, aluminum frames, plastic plates, semiconductor wafers, circuit boards, ceramics, glass, quartz and other engineering components and electronic and electrical components such as sensors, especially precision processing such as cutting, grinding, grinding, etc., for To prevent damage to the machined surface of the workpiece, circuits, sensor parts, etc., and foreign matter from adhering, surface protection films are widely used to temporarily protect parts. As the surface protection film, a pressure-sensitive adhesive sheet is mainly used.

For example, when thinning semiconductor wafers, optical components, etc., processing is performed by a so-called back grinding method. The so-called back grinding method is to protect the circuit surface of the wafer and the non-processed surface of the optical component with a surface protection sheet, temporarily fix these components to the substrate through the surface protection sheet, and grind the back surface opposite to the circuit surface .

However, the currently used pressure-sensitive adhesive surface protection sheet has a limit in followability to the unevenness of the circuit of the semiconductor wafer. Therefore, contamination by grinding fluid and the like entering between the wafer and the surface protective layer often becomes a problem. In addition, when a semiconductor wafer is diced, a typical semiconductor surface protection sheet cannot follow a protrusion of 100 μm or more typified by a bump, and there is a problem of contamination and scattering of debris.

Conventional surface protection sheets generally have an adhesive layer on a polymer film material as a surface protection layer, and the adhesive is designed to have a low modulus of elasticity in order to follow the unevenness of the circuit surface. However, if the elastic modulus is too low, a large stress is applied to the wafer when the sheet is peeled and removed from the wafer, resulting in breakage of the wafer.

Therefore, an energy ray easily peelable protective sheet has been developed in which the adhesive is cured by irradiating energy rays such as ultraviolet rays before the sheet is peeled off, thereby reducing the adhesive force between the wafer and the protective sheet. However, the adhesive bond layer is in an uncured state during grinding, and there is a problem that the wafer is broken during grinding because it is too soft.

Patent Document 1 discloses a wafer grinding method in which the above-mentioned energy ray easily peelable protective sheet is attached to a wafer on which a circuit is formed, the adhesive layer is cured by energy ray, and then the back surface of the wafer is ground. However, since the adhesive is not a fluid, it does not have sufficient followability to irregularities on the circuit surface of the wafer.

On the other hand, Patent Document 2 discloses a hot-melt type semiconductor surface protection sheet. A hot-melt sheet that melts by heating at 60 to 100°C and exhibits fluidity can follow the unevenness of the circuit surface and exhibit excellent grindability. However, this sheet has a property of melting every time the temperature exceeds the melting point.

In order to solve the above-mentioned problems, the present inventors proposed a resin composition containing a resin containing a specific (meth)acrylic monomer, which not only has sufficient followability to the unevenness of the circuit surface of the optical component, In addition, it has sufficient rigidity as a support during grinding (see Patent Documents 3 and 4). The above resin composition is effective for surface protection during back grinding. However, for surface protection, a resin composition that has completely cured the surface is required. This is because the surface may not be completely cured if polymerization inhibition by oxygen is received during the surface protection during grinding and dicing.

On the other hand, different from the surface protection sheet, it is studied to apply an ultraviolet-curable adhesive dissolved in a specific organic solvent on the surface of the processed object, and to make it UV-cured and coated to protect the surface from cutting chips during processing. method. However, due to the use of organic solvents, the cleaning process is complicated, and there are problems in the working environment. In addition, when there are fine unevenness, the organic solvent cannot penetrate sufficiently, and the protective film cannot be completely removed, so the appearance of the workpiece occurs. question.

As a composition that has sufficient followability to irregularities on the circuit surface of wafers, optical components, etc., and has sufficient rigidity as a support during grinding, a (meth)acrylic monomer and a resin containing a cyclopentadiene skeleton have been proposed. component resin composition (see Patent Document 5).

prior art literature

patent documents

Patent Document 1: Japanese Patent Application Laid-Open No. 11-026406

Patent Document 2: Japanese Unexamined Patent Publication No. 2000-038556

Patent Document 3: International Publication WO2007/004620 Pamphlet

Patent Document 4: International Publication WO2006/100788 Pamphlet

Patent Document 5: Japanese Patent Laid-Open No. 2007-186587

Contents of the invention

However, in the above-mentioned Patent Document 5, there is no description of a heating step in which a protective film is provided on the surface of the workpiece using the above-mentioned resin composition, and the heating process is performed at 80 to 150°C. Also, there is no description that when a heating step is provided, the protective film does not fall off during processing even if cutting is performed.

The inventors of the present invention have carried out intensive studies in order to solve the above-mentioned problems. As a result, they have found that after the protective film formed of the above-mentioned curable composition is provided on the surface of the workpiece, heat treatment of the protective film is performed, and then the workpiece is processed. The present invention has been accomplished by being able to protect the surface of the above workpiece without peeling off the protective film during processing.

That is, the present invention relates to a method for protecting the surface of a workpiece, characterized in that in the method for protecting the surface of a workpiece in which a protective film formed of a curable composition is provided on the surface of the workpiece, the surface layer of the workpiece After the protective film is combined, the process of heating the protective film is carried out, and then the workpiece is processed.

In addition, the present invention relates to a method for temporarily fixing a workpiece, which is characterized in that a protective film formed of a curable composition is provided on the surface of the workpiece, and after heat treatment, the workpiece is processed, and then dipped in 90 The protective film formed from the above-mentioned curable composition is removed from the above-mentioned workpiece with warm water below °C.

Specifically, the present invention is as follows.

The present invention relates to a method for protecting the surface of a workpiece in which a protective film is laminated on the surface of the workpiece, characterized in that it comprises the following steps: a lamination step of laminating a protective film made of a cured body on the surface of the workpiece, The cured body is formed from a curable composition containing the following (A), (B) and (C); a heating step of performing a heat treatment at 80 to 150° C. after the lamination step; The processing procedure for processing parts.

(A) Multifunctional (meth)acrylate

(B) Monofunctional (meth)acrylate

(C) Photopolymerization initiator

Moreover, it is related with the surface protection method of the workpiece of Claim 1 in which the said protective film contains (D) resin which has a cyclopentadiene skeleton.

Moreover, it is related with the surface protection method of this workpiece, wherein said (D) resin which has a cyclopentadiene skeleton contains an ester group or a hydroxyl group in a molecule|numerator.

Moreover, it is related with the surface protection method of this to-be-processed object in which all of said (A) polyfunctional (meth)acrylate and said (B) monofunctional (meth)acrylate are hydrophobic.

Moreover, it is related with the surface protection method of this workpiece|work, wherein said curable composition contains 5-50 mass parts of (A) polyfunctional (methyl) Acrylate and 50 to 95 parts by mass of (B) monofunctional (meth)acrylate, relative to the total amount of (A) and (B) 100 parts by mass, containing 0.1 to 20 parts by mass of (C) photopolymerization initiator and 0.1-50 mass parts (D) Resin which has a cyclopentadiene frame|skeleton.

In addition, it relates to a method for temporarily fixing a workpiece in which a protective film is laminated on the surface of the workpiece, and is characterized in that it includes the following steps: a lamination step of laminating a protective film made of a cured body on the surface of the workpiece, The cured body is formed from a curable composition containing the following (A), (B) and (C); after the lamination process, a heating process of heat treatment at 80 to 150 ° C is performed; after the heating process, the workpiece is processed The processing step of processing; and the removal step of immersing the workpiece in warm water of 90° C. or lower after the processing step, and removing the protective film from the workpiece.

(A) Multifunctional (meth)acrylate

(B) Monofunctional (meth)acrylate

(C) Photopolymerization initiator

The method for protecting the surface of a workpiece according to the present invention achieves the effect that the protective film does not fall off even when processing such as cutting is performed, and can prevent damage and adhesion of foreign matter to the processed surface of the workpiece, circuits, sensor parts, and the like.

Detailed ways

The invention relates to a method for protecting the surface of a workpiece, which is characterized in that: after the surface of the workpiece is provided with a protective film formed of a curable composition, the protective film is heated at 80 to 150°C, and then the workpiece is processed. processing, so as to prevent the peeling off of the protective film during processing.

From the viewpoint of maintaining the peelability of the protective film, the temperature of the heat treatment is preferably 80 to 150°C, more preferably 90 to 120°C. If it is 80° C. or higher, the effect of the heat treatment can be obtained, and if it is 150° C. or lower, the releasability is good.

The curable composition used as a protective film in the present invention preferably contains (A) polyfunctional (meth)acrylate, (B) monofunctional (meth)acrylate, (C) A photopolymerization initiator and (D) a cyclopentadiene skeleton-containing resin.

As the (A) polyfunctional (meth)acrylate used in the above-mentioned curable composition, polyfunctional (meth)acrylate oligomers/polymers/units having two or more (meth)acryloyl groups can be used. body. For example, as a multifunctional (meth)acrylate oligomer/polymer, 1,2-polybutadiene-terminated urethane (meth)acrylate (for example, manufactured by Nippon Soda Corporation, "TE -2000", "TEA-1000"), the above-mentioned hydrides (for example, "TEAI-1000" manufactured by Nippon Soda Co., Ltd.), 1,4-polybutadiene terminal urethane (meth)acrylate (e.g., "BAC-45" manufactured by Osaka Organic Chemicals Co., Ltd.), polyisoprene-terminated (meth)acrylate, urethane acrylate (e.g., "UV-7000B" manufactured by Nippon Gosei Co., Ltd.), polyester-based amino Formate (meth)acrylate (for example, "UV-3000B" manufactured by Nippon Gosei Co., Ltd.), polyether-based urethane (meth)acrylate, polyester (meth)acrylate, bisphenol A epoxy (meth)acrylate (for example, "Biscoat #540" manufactured by Osaka Organic Chemical Co., Ltd., "Biscoat VR-77" manufactured by Showa High Molecular Co., Ltd.), and the like. Among these, it is preferable to select from the group consisting of 1,2-polybutadiene-terminated urethane (meth)acrylate, urethane acrylate oligomer, and polyester-based urethane acrylic acid in that the effect of releasability is large. One or more of ester oligomers, more preferably 1,2-polybutadiene-terminated urethane (meth)acrylate.

In addition, examples of bifunctional (meth)acrylate monomers include 1,3-butylene glycol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, di(meth)acrylate ) 1,6-hexanediol acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dicyclopentyl di(meth)acrylate ( dicyclopentanyl) ester, 2-ethyl-2-butyl-propylene glycol (meth)acrylate, neopentyl glycol modified trimethylolpropane di(meth)acrylate, stearic acid modified pentaerythritol di(meth)acrylate base) acrylate, polypropylene glycol di(meth)acrylate, 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane, 2,2-bis(4-(meth) base) acryloyloxypropoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytetraethoxyphenyl)propane, etc.

Examples of the trifunctional (meth)acrylate monomer include trimethylolpropane tri(meth)acrylate, tris[(meth)acryloyloxyethyl]isocyanurate, and the like.

Examples of the (meth)acrylate monomer having four or more functions include dimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol ethoxy tetra(meth)acrylate, Dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like.

Among these, dicyclopentyl di(meth)acrylate and/or 1,6-hexanediol di(meth)acrylate are preferable, and di(methyl) Dicyclopentyl acrylate.

Among the (A) polyfunctional (meth)acrylates, it is preferable to polymerize/polymerize polyfunctional (meth)acrylate oligomers and and 2-functional (meth)acrylate monomers are used together. The effect of the mixing ratio (mass ratio) of a polyfunctional (meth)acrylate oligomer/polymer having two or more (meth)acryloyl groups and a bifunctional (meth)acrylate monomer on peelability On a larger scale, it is preferably 30-100:70-0, more preferably 50-65:50-35.

The (A) polyfunctional (meth)acrylate used in the present invention is more preferably hydrophobic. In the case of hydrophobicity, it is possible to prevent the phenomenon that often occurs in the case of water-solubility, that is, the phenomenon that the cured body of the curable composition swells during processing to cause positional displacement and poor processing accuracy. Here, the hydrophobic polyfunctional (meth)acrylate means the (meth)acrylate which does not have a hydroxyl group. For example, the above-mentioned polyfunctional (meth)acrylate etc. are mentioned. Among them, preferably selected from 1,2-polybutadiene-terminated urethane (meth)acrylate, 1,6-hexanediol di(meth)acrylate and dicyclopentane di(meth)acrylate One or two or more of base esters. Even if it is hydrophilic, it can be used as long as the cured body of the curable composition is not greatly swollen or partially dissolved by water.

(A) The usage-amount of a polyfunctional (meth)acrylate is preferably 5-50 mass parts in 100 mass parts of total amounts of (A) and the (B) monofunctional (meth)acrylate component mentioned later, More preferably, it is 20-40 mass parts. If it is 5 parts by mass or more, it is possible to prevent a decrease in peelability or to prevent the cured body of the curable composition from becoming a film, and if it is 50 parts by mass or more, there is no fear that the curing shrinkage will increase and the initial adhesiveness will decrease.

Examples of (B) monofunctional (meth)acrylate monomers used in the curable composition include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, ( Butyl methacrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, (meth)acrylic acid Stearyl ester, phenyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentene (meth)acrylate Dicyclopentenyloxyethyl (meth)acrylate, Isobornyl (meth)acrylate, Methoxylated cyclodecatriene (meth)acrylate, 2-Hydroxyethyl (meth)acrylate ester, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (meth)acrylic acid 2-Hydroxy-3-phenoxypropyl ester, glycidyl (meth)acrylate, ω-carboxy-polycaprolactone mono(meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate Ester, 3-chloro-2-hydroxypropyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, ( tert-butylaminoethyl methacrylate, ethoxycarbonylmethyl (meth)acrylate, phenol ethylene oxide modified (meth)acrylate, phenol (ethylene oxide 2 mole modified) (methyl) base) acrylate, phenol (ethylene oxide 4 mole modified) (meth)acrylate, p-cumylphenol ethylene oxide modified (meth)acrylate, nonylphenol ethylene oxide modified ( Meth)acrylate, nonylphenol (modified by 4 moles of ethylene oxide) (meth)acrylate, nonylphenol (modified by 8 moles of ethylene oxide) (meth)acrylate, nonylphenol ( Propylene oxide 2.5 mole modification) (meth)acrylate, 2-ethylhexyl carbitol (meth)acrylate, ethylene oxide modified phthalate (meth)acrylate, ethylene oxide Alkyl-modified succinic acid (meth)acrylate, trifluoroethyl (meth)acrylate, acrylic acid, methacrylic acid, maleic acid, fumaric acid, ω-carboxy-polycaprolactone mono(meth)acrylic acid ester, monohydroxyethyl (meth)acrylate phthalate, (meth)acrylic acid dimer, β-(meth)acryloyloxyethyl hydrosuccinate, n-(meth)acrylic acid Acyloxyalkylhexahydrophthalimide, 2-(1,2-cyclohexanedicarboxyimide)ethyl(meth)acrylate, and the like.

Among these, it is preferable to select from 2-(1,2-cyclohexanedicarboxyimide) ethyl (meth)acrylate, phenol oxirane 2 mole modified ( Meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, benzyl (meth)acrylate, ω-carboxy-polycaprolactone mono(meth)acrylate and (meth)acrylic acid2 - One or more of hydroxy-3-phenoxypropyl esters, more preferably 2-(1,2-cyclohexanedicarboxyimide) ethyl (meth)acrylate and/or phenol ring Oxyethane 2 mole modified (meth)acrylate. The mixing ratio (mass ratio) of 2 moles of phenol oxirane modified (meth)acrylate and 2-(1,2-cyclohexanedicarboximide) ethyl (meth)acrylate, in stripping In terms of the large effect of sex, it is preferably 20-70:80-30, more preferably 30-45:70-55.

It is preferable that (B) monofunctional (meth)acrylate is hydrophobic similarly to (A) component.

Here, hydrophobicity means (meth)acrylate which does not have a hydroxyl group. In the case of hydrophobicity, it is possible to prevent the phenomenon that often occurs in the case of water-solubility, that is, the phenomenon that the cured body of the curable composition swells during processing to cause positional displacement and poor processing accuracy. Even if it is hydrophilic, it can be used as long as the cured body of the curable composition is not greatly swollen or partially dissolved by water.

(B) The usage-amount of a monofunctional (meth)acrylate is 50-95 mass parts in 100 mass parts of total amounts of (A) component and (B) component, More preferably, it is 60-80 mass parts. If it is 50 parts by mass or more, there is no fear of a decrease in initial adhesiveness, and if it is 95 parts by mass or less, a cured body of the curable composition can be obtained in a film form without a decrease in releasability.

In addition, by further using (meth)acryloyloxyethyl acid phosphoric acid ester and dibutyl 2-(meth)acryloyloxyethyl acid phosphoric acid in combination with (A) component and (B) component of the above-mentioned composition, Dioctyl 2-(meth)acryloyloxyethyl phosphate, Diphenyl 2-(meth)acryloyloxyethyl phosphate, (meth)acryloyloxyethyl polyethylene glycol Phosphate esters having a vinyl group or a (meth)acryloyl group such as formula phosphate ester can further improve the adhesion to the metal surface.

The photopolymerization initiator (C) used in the above-mentioned curable composition is used to sensitize it with active rays such as visible rays and ultraviolet rays to accelerate photocuring of the curable composition, and various known photopolymerization initiators can be used. Specifically, benzophenone and its derivatives, benzil and its derivatives, anthraquinone and its derivatives, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, Benzoin derivatives such as benzoin isobutyl ether and benzil dimethyl ketal, acetophenone derivatives such as diethoxyacetophenone and 4-tert-butyltrichloroacetophenone, benzoic acid 2 -Dimethylaminoethyl ester, p-dimethylaminoethyl benzoate, diphenyl disulfide, thioxanthone and its derivatives, camphorquinone, 7,7-dimethyl-2,3-di Oxobicyclo[2.2.1]heptane-1-carboxylic acid, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxy-2-bromoethyl ester, 7,7-Dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxy-2-methyl ester, 7,7-dimethyl-2,3-dioxobicyclo[ 2.2.1] Camphorquinone derivatives such as heptane-1-carboxylic acid chloride, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl Base-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 and other α-aminoalkylphenone derivatives, benzoyldiphenylphosphine oxide, 2,4,6 -Trimethylbenzoyldiphenylphosphine oxide, benzoyldiethoxyphosphine oxide, 2,4,6-trimethylbenzoyldimethoxyphenylphosphine oxide, 2,4,6- Acylphosphine oxide derivatives such as trimethylbenzoyldiethoxyphenylphosphine oxide and the like. (C) The photoinitiator can use these 1 type or in combination of 2 or more types.

(C) The usage-amount of a photoinitiator is preferably 0.1-20 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component, More preferably, it is 3-10 mass parts. When it is 0.1 mass part or more, the effect of accelerating hardening can be acquired reliably, and when it is 20 mass parts or less, sufficient hardening rate can be realizable. As a more preferable aspect, by using 3 mass parts or more of (C)component, it can harden|cure independently of light irradiation amount.

The (D) resin having a cyclopentadiene skeleton used in the present invention may be any resin as long as it is a resin having a cyclopentadiene skeleton, but the softening point is preferably 50 to 200°C. In terms of solubility in the ) component, resins having a number average molecular weight (Mn) of 300 to 600 are more preferable. The softening point was measured in accordance with JIS K 2207 ring and ball method. The measurement of the number average molecular weight is based on GPC (gel permeation chromatography) polystyrene conversion value. Examples of (D) include petroleum resins produced from cyclopentadiene extracted from C5 fractions as the main raw material, specifically, "Quintone 1700", "Quintone 1500", "Quintone 1325" manufactured by Japan Zeon Corporation, etc. "wait. Among them, it is preferable to contain a hydroxyl group in terms of adhesiveness. "Quintone 1700" etc. are mentioned as a resin containing a hydroxyl group.

(D) The usage-amount of the resin which has a cyclopentadiene skeleton is preferably 0.5-50 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component, More preferably, it is 5-30 mass parts. If it is 0.5 mass parts or more, it will not remain as a paste without forming a film, and if it is 50 mass parts or less, adhesiveness will not fall.

In order to improve the storage stability of the curable composition of this invention, a small amount of polymerization inhibitor can be used. For example, as a polymerization inhibitor, methylhydroquinone, hydroquinone, 2,2-methylene-bis(4-methyl-6-tert-butylphenol), catechol, hydroquinone monomethyl ether, Mono-tert-butyl hydroquinone, 2,5-di-tert-butyl hydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, 2,5-di-tert-butyl-p-benzoquinone, picric acid, citric acid, Phenothiazine, tert-butyl catechol, 2-butyl-4-hydroxyanisole and 2,6-di-tert-butyl-p-cresol, etc.

Among these, one or more selected from 2,2-methylene-bis(4-methyl-6-tert-butylphenol), hydroquinone monomethyl ether and p-benzoquinone is preferred, more preferably 2 , 2-methylene-bis(4-methyl-6-tert-butylphenol).

The usage-amount of these polymerization inhibitors is preferably 0.001-3 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component, More preferably, it is 0.01-2 mass parts. When it is 0.001 mass part or more, storage stability is sufficient, and when it is 3 mass parts or less, reliable adhesiveness can be acquired, and there is no need to worry about uncured.

As the curable composition used in the present invention, various elastomers such as acrylic rubber, urethane rubber, acrylonitrile-butadiene-styrene rubber, and inorganic fillers that are generally used can be used within the range that does not impair the purpose of the present invention. , solvents, extenders, reinforcing materials, plasticizers, tackifiers, dyes, pigments, flame retardants, silane coupling agents and surfactants and other additives.

The present invention relates to a method for protecting the surface of a workpiece, which is characterized in that a protective film formed of the above-mentioned curable composition is provided on the surface of the workpiece, and after the protective film is heat-treated, the workpiece is processed to prevent The peeling of the protective film during processing protects the surface of the workpiece.

As a lamination step of laminating a protective film on the surface of the workpiece, it is preferable to apply a curable composition with a thickness of 20 to 200 μm, preferably 50 to 150 μm, on the surface of the workpiece to form a protective film. A step of curing under the conditions of 1000 to 4000 mJ/cm ² , preferably 1500 to 3000 mJ/cm ² .

As the heating step of performing heat treatment after the lamination step, a step of heat-treating the protective film at 80 to 150° C., preferably 80 to 120° C., for 5 to 30 minutes is preferable.

As the processing step of processing the workpiece after the heating step, the following step is preferable: at a rotation speed of 5,000 to 40,000 rpm, preferably 10,000 to 35,000 rpm, a conveying speed of 0.2 to 50 mm/sec, preferably 0.5 to 30 mm/sec, and a slice size of 0.5 to 15 mm square conditions for cutting.

In addition, the present invention relates to a temporary fixing method of a workpiece, which is characterized in that a protective film formed of a curable composition is provided on the surface of the workpiece, and after heat treatment, the workpiece is processed, and then dipped A removing step of removing the protective film formed of the above-mentioned curable composition from the above-mentioned workpiece in warm water of 70 to 90°C or lower, preferably in warm water of 75 to 85°C.

When the cured body of the above-mentioned curable composition is removed, it can be recovered from the parts in the form of a film, thereby obtaining an effect of excellent workability. In addition, as for the method of contacting the solidified body with warm water, the method of immersing the workpiece together with the warm water is recommended because it is convenient.

Example

The following examples are given to describe the present invention in more detail, but the present invention is not limited to the examples and interpreted.

In addition, Experimental Examples I-1 to I-15 are examples of the present invention, and Experimental Examples II-1 to II-5 are comparative examples.

(Experimental example I-1)

"TE-2000" (1,2-polybutadiene-terminated urethane methacrylate, hereinafter abbreviated as "TE" manufactured by Nippon Soda Co., Ltd. as (A) multifunctional (meth)acrylate -2000") 20 parts by mass, dicyclopentyl diacrylate (manufactured by Nippon Kayaku Co., Ltd., "KAYARAD R-684" hereinafter referred to as "R-684") 15 parts by mass, as (B) monofunctional (methyl 40 parts by mass of 2-(1,2-cyclohexanedicarboxyimide) ethyl acrylate (manufactured by Toagosei Co., Ltd., "Aronix M-140", hereinafter referred to as "M-140") and phenol (C) 2-Methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (manufactured by Ciba Specialty Chemicals Co., Ltd., "IRGACURE907", hereinafter referred to as "I -907") 6 parts by mass, as (D) cyclopentadiene skeleton resin (manufactured by Nippon Zeon Co., Ltd., "Quintone 1700", containing hydroxyl groups, softening point: 100°C, number average The molecular weight is 380. Hereinafter abbreviated as "Quintone1700") 10 parts by mass, 2,2-methylene-bis(4-methyl-6-tert-butylphenol) (hereinafter abbreviated as "MDP") as a polymerization inhibitor 0.1 parts by mass to prepare a curable composition. Using the obtained curable composition, the measurement of the tensile shear adhesive strength, the adhesiveness test, and the peeling test were performed by the evaluation method shown below. The results are shown in Table 1.

(Evaluation method)

Adhesive strength (tensile shear adhesive strength):

Adhesive strength (tensile shear adhesive strength) was measured in accordance with JIS K 6850. Specifically, heat-resistant Pyrex (registered trademark) glass (25 mm×25 mm×2.0 mm (length×width×thickness)) was used as a material to be adhered. The bonded part is a circle with a diameter of 8 mm, and two sheets of heat-resistant Pyrex (registered trademark) glass are bonded together with a curable composition prepared at a thickness of 100 μm. It was cured under the condition that the cumulative light intensity of the wavelength was 2000mJ/cm ² , and a tensile shear adhesive strength test piece was produced. For the produced test piece, the tensile shear adhesive strength was measured at a tensile speed of 10 mm/min in an environment with a temperature of 23° C. and a humidity of 50% using a universal testing machine.

The maintenance status of the protective film after cutting (adhesion test):

The adhesion test was performed in the environment of temperature 23 degreeC, and humidity 50%. The curable composition was applied to a thickness of 100 μm on a silicon wafer, and the curable composition was cured under the condition of a cumulative light intensity of 2000 mJ/cm at ^a wavelength of 365 nm by using a curing device manufactured by Fusion Corporation using an electrodeless discharge lamp. Make a protective film. Then, after heat-treating the protective film at 100° C. for 10 minutes, cutting was carried out under the conditions of rotation speed 30,000 rpm, conveying speed 1.0 mm/sec, and slice size 1 mm square, and whether the protective film remained after cutting was observed. The number of slices holding the protective film among the 25 slices was counted.

Peeling time in warm water at 80°C (peeling test):

After immersing in warm water (80 degreeC) about the test body which maintained the protective film after the said dicing, the time until the protective film peeled off from a silicon wafer was measured.

Observation of peeling state (peeling test):

After the test using the peeling time (peeling test) of the above-mentioned 80° C. warm water, the peeled protective film was observed.

[Table 1]

[Table 2]

(Experimental example I-2, I-3, I-11 and I-12)

Except having heat-processed at the temperature shown in Table 1, the curable composition was produced similarly to Experimental example I-1. About the obtained curable composition, it evaluated similarly to Experimental example I-1. These results are shown in Table 1.

(Experimental example I-4～I-10 and I-13～I-15)

Except having used the raw material of the kind shown in Table 1 in the composition shown in Table 1, it carried out similarly to Experimental example I-1, and produced curable composition. About the obtained curable composition, it evaluated similarly to Experimental example I-1. These results are shown in Table 1.

(used material)

QM: Dicyclopentenyloxyethyl methacrylate (manufactured by Rohm & Hass, "QM-657")

BZ: Benzyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., "Light Ester BZ")

UV-7000B: Urethane acrylate oligomer (manufactured by Nippon Synthetic Chemicals Co., Ltd., "UV-7000B")

UV-3000B: Polyester-based urethane acrylate oligomer (manufactured by Nippon Synthetic Chemicals Co., Ltd., "UV-3000B")

1,6-HX-A: 1,6-hexanediol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., "Light Acrylate 1,6-HX-A")

M-5300: ω-carboxy-polycaprolactone monoacrylate (manufactured by Toagosei Co., Ltd., "Aronix M-5300")

M-5710: 2-Hydroxy-3-phenoxypropyl acrylate (manufactured by Toagosei Co., Ltd., "Aronix M-5710")

Quintone 1500: Cyclopentadiene skeleton resin (manufactured by Nippon Zeon Co., Ltd., "Quintone 1500", contains an ester group, has a softening point of 125°C, and a number average molecular weight of 470)

BDK: benzil dimethyl ketal (manufactured by Ciba Specialty Chemicals, "IRGACURE651")

(Experimental Examples II-1 and II-2)

Except having heat-processed at the temperature shown in Table 2, the curable composition was produced similarly to Experimental example I-1. About the obtained curable composition, it evaluated similarly to Experimental example I-1. These results are shown in Table 2. In addition, "-" in the heat treatment temperature of Experimental Example II-1 means that no heat treatment was performed.

(Experimental examples II-3 to II-5)

Except having used the raw material of the kind shown in Table 2 in the composition shown in Table 2, it carried out similarly to Experimental example I-1, and produced curable composition. About the obtained curable composition, it evaluated similarly to Experimental example I-1. These results are shown in Table 2.

[table 3]

(used material)

IBX: Isobornyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., "Light Ester IB-X")

As a result, in Experimental Example II-1, since dicing was performed without heat treatment, the protective film peeled off during dicing. In addition, in Experimental Example II-2, the protective film was held without peeling during dicing, but since the temperature of the heat treatment was too high, the peelability was lowered, and then hot water peeling could not be performed.

In addition, in Experimental Example II-3, since the (A) polyfunctional (meth)acrylate was not compounded, the cured body of the curable composition became thermoplastic, and the protective film was dissolved due to the heat treatment before processing, and the protective film could not be protected. surface. Moreover, in Experimental Example II-4, since (C) photoinitiator was not mix|blended, it did not harden even after light irradiation. In Experimental Example II-5, since the (B) monofunctional (meth)acrylate was not blended, the deformation due to curing shrinkage was large, and cracks were observed on the surface of the cured body. In Experimental Example II-5, the cured body of the curable composition did not peel off from the wafer.

On the other hand, in Experimental Examples I-1 to I-14, dicing was performed after the heat treatment, so in all cases, the protective film did not come off during dicing, and the surface could be protected. In addition, in Experimental Examples I-1 to I-14, (A) polyfunctional (meth)acrylate and (B) monofunctional (meth)acrylate are mixed together with photopolymerization initiator in a balanced manner, so The adhesive strength of the curable composition after photopolymerization is sufficient, and the peeling state when the cured body of the curable composition is peeled from the silicon wafer after dicing is also good. Moreover, the surface of the cut silicon wafer is also well protected. In addition, in Experimental Example I-15, since the (D) cyclopentadiene skeleton resin was not blended, the surface was not completely cured and stickiness was observed, but the adhesive strength was good.

In the present invention, the above-mentioned protective film is provided on the surface of the workpiece, and after the protective film is heat-treated, the workpiece is processed, thereby preventing the peeling of the protective film during processing, so the surface of the workpiece can be protected from damage. ,pollute. In addition, the curable composition of the present invention has sufficient followability to irregularities on surfaces such as circuit surfaces, and can protect not only smooth surfaces but also surfaces with irregularities from damage and contamination.

The protective film of the present invention can be recovered from the workpiece in the form of a film by immersing it in warm water of 90° C. or lower after processing the workpiece, and thus has an effect of being excellent in workability. In addition, there is no need to use an organic solvent, which is essential for conventional adhesives, and an effect of reducing environmental load is obtained.

In the present invention, a protective film is provided on the surface of a workpiece using the curable composition described above. The present invention can obtain the effect that, for example, the protective film does not come off during processing even if cutting is performed under the condition of a conveying speed of 2 mm/sec or less.

In the surface protection method of the present invention, the protective film formed from the curable composition has photocurability due to its composition and can be cured by visible light and ultraviolet rays, so compared with conventional hot melt adhesives, it can save labor and energy. , Job shortening achieved significant results. In addition, after the protective film is laminated on the surface of the workpiece, the internal deformation of the protective film can be alleviated by a heat treatment process, and the peeling of the protective film can be suppressed in the subsequent processing of the workpiece. In addition, by using the above-mentioned method, the above-mentioned protective film exhibits high adhesive strength without affecting the cutting fluid etc. attached.

Since the above-mentioned effects are obtained, the present invention is useful in the processing of electronic and electrical components such as engineering components and sensors, especially in the industries of precision processing such as cutting, grinding, and grinding.

In addition, all the content of the specification, a claim, and the abstract of the Japanese patent application 2008-125321 for which it applied on May 12, 2008 are referred here, and it takes in as disclosure of the specification of this invention.

Claims (6)

1. The method for protecting the surface of a workpiece by laminating a protective film on the surface of the workpiece, comprising the steps of: laminating a protective film made of a cured body on the surface of the workpiece, the The cured body is formed from a curable composition containing the following (A), (B) and (C); a heating process of performing a heat treatment at 80 to 150° C. after the lamination process; the process of processing, (A) Multifunctional (meth)acrylate (B) Monofunctional (meth)acrylate (C) Photopolymerization initiator. 2. The method for protecting the surface of a workpiece according to claim 1, wherein the protective film contains (D) a resin having a cyclopentadiene skeleton. 3. The method for protecting the surface of a workpiece according to claim 2, wherein the (D) resin having a cyclopentadiene skeleton contains an ester group or a hydroxyl group in a molecule. 4. The surface protection method of a workpiece according to any one of claims 1 to 3, wherein the (A) multifunctional (meth)acrylate and the (B) monofunctional (methyl) Acrylates are hydrophobic. 5. The surface protection method of a workpiece according to any one of claims 2 to 4, wherein the curable composition contains 5 to 100 parts by mass of the total amount of (A) and (B). 50 parts by mass of (A) polyfunctional (meth)acrylate and 50 to 95 parts by mass of (B) monofunctional (meth)acrylate, with respect to the total amount of (A) and (B) 100 parts by mass, containing 0.1 -20 parts by mass of (C) a photopolymerization initiator and 0.1-50 parts by mass of (D) a resin having a cyclopentadiene skeleton. 6. A method for temporarily fixing a workpiece by laminating a protective film on the surface of the workpiece, comprising the following steps: a lamination step of laminating a protective film made of a cured body on the surface of the workpiece, the The cured body is formed from a curable composition containing the following (A), (B) and (C); after the lamination process, a heating process of heat treatment at 80 to 150 ° C is performed; after the heating process, the workpiece is processed a processing step of processing; and a removing step of immersing the workpiece in warm water of 90° C. or lower after the processing step to remove the protective film from the workpiece, (A) Multifunctional (meth)acrylate (B) Monofunctional (meth)acrylate (C) Photopolymerization initiator.