JP2011132354A - Ultraviolet-curing adhesive film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultraviolet-curing adhesive film which has large adhesive force, has excellent peelability after ultraviolet irradiation, and generates little residual paste at peeling. <P>SOLUTION: The ultraviolet curing adhesive film includes a base film 13, and an adhesive layer 12 formed on one principal plane of the base film 13, wherein the adhesive layer 12 contains an adhesive material, an ultraviolet curing material, and an ultraviolet polymerization initiator, and the ultraviolet curing material contains a polyfunctional thiol compound. The adhesive material is preferably an acrylic polymer. The adhesive layer 12 preferably contains 10-40 pts.wt. of a polyfunctional thiol compound based on 100 pts.wt. of an acrylic polymer. Furthermore, the adhesive layer 12 preferably contains a thermosetting material. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an adhesive film used for protecting circuit patterns and the like during semiconductor manufacturing.

  In the semiconductor manufacturing process, after a circuit pattern or the like is formed on the surface of the semiconductor wafer, a back grinding process is performed in which the back surface of the semiconductor wafer is ground to a predetermined thickness. In that case, in order to protect the circuit pattern etc. of a semiconductor wafer, the adhesive film is affixed on the surface of a semiconductor wafer. This adhesive film is peeled off from the semiconductor wafer after the back grinding process is completed.

  As a characteristic of the adhesive film that protects the semiconductor wafer, in addition to being able to reliably protect the circuit pattern of the semiconductor wafer, the adhesive does not remain on the surface of the semiconductor wafer after peeling the adhesive film (adhesive residue), It is required that grinding water used for washing away grinding scraps and cooling during grinding does not enter the surface of the semiconductor wafer, and that the thickness accuracy of the semiconductor wafer after grinding can be sufficiently maintained.

  Examples of the pressure-sensitive adhesive film include a blend-type pressure-sensitive adhesive film (see, for example, Patent Document 1) in which a pressure-sensitive adhesive layer containing a pressure-sensitive polymer and a photopolymerizable oligomer or monomer is formed on a substrate, and carbon-carbon double. There is an adduct type adhesive film (for example, refer to Patent Document 2) in which an adhesive layer containing an adhesive polymer having a bond is formed on a substrate. All of the above adhesive films are affixed to the surface of a semiconductor wafer, and after the back grinding process is completed, the adhesive power of the adhesive polymer is reduced by irradiating ultraviolet rays or the like, and then peeled off from the semiconductor wafer.

JP 60-189938 A JP 2008-60151 A

  A blend type adhesive film is one that polymerizes oligomers or monomers by irradiation with ultraviolet rays to reduce the adhesive strength of the pressure-sensitive adhesive layer. There is a problem that there are relatively many. This is presumably because oxygen present in the polymerization atmosphere inhibits polymerization of oligomers and the like.

  On the other hand, the adduct type adhesive film is one in which the adhesive polymer itself having a carbon-carbon double bond is polymerized by irradiation of ultraviolet rays and the adhesive strength of the adhesive layer is lowered. Although there are few, there exists a problem that the material cost of an adhesive rises.

  The present invention solves the above problems and provides a blend-type pressure-sensitive adhesive film with little adhesive residue at the time of peeling after ultraviolet irradiation.

  The ultraviolet curable adhesive film of the present invention is an ultraviolet curable adhesive film including a substrate and an adhesive layer formed on one main surface of the substrate, and the adhesive layer is an adhesive material. And an ultraviolet curable material and an ultraviolet polymerization initiator, wherein the ultraviolet curable material contains a polyfunctional thiol compound.

  According to the present invention, it is possible to provide an inexpensive ultraviolet curable adhesive film having a large adhesive force, excellent peelability after ultraviolet irradiation, and having little adhesive residue at the time of peeling.

It is a schematic cross section which shows an example of the ultraviolet curable adhesive film of this invention.

  First, the ultraviolet curable adhesive film of this invention is demonstrated. The ultraviolet curable adhesive film of this invention is equipped with the base material and the adhesive layer formed in one main surface of the said base material.

(Adhesive layer)
The pressure-sensitive adhesive layer includes a pressure-sensitive adhesive material, an ultraviolet curable material, and an ultraviolet polymerization initiator, and the ultraviolet curable material further includes a polyfunctional thiol compound.

  By including a polyfunctional thiol compound in the UV curable material of the pressure-sensitive adhesive layer, it is possible to suppress polymerization inhibition due to oxygen during UV irradiation, thereby reducing the residual monomer, and thus reducing the adhesive residue when peeling the pressure-sensitive adhesive film. While being able to reduce, the adhesive force of an adhesive layer can be reduced reliably and the said adhesive film can be peeled easily.

  Although it does not specifically limit as said adhesive material, It is preferable to use an acrylic polymer from points, such as the adhesiveness to a semiconductor wafer or a board | substrate, and the ease of adjustment of adhesive force.

  Examples of the acrylic polymer include acrylic polymers obtained by polymerizing or copolymerizing one or more of (meth) acrylic acid esters or derivatives thereof as monomer components. As the (meth) acrylic acid ester monomer, for example, an alkyl group having 2 to 14 carbon atoms and a glass transition temperature of −20 ° C. or lower can be used. Specifically, ethyl acrylate, butyl acrylate, Examples include hexyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate, nonyl methacrylate, dodecyl methacrylate, and the like. In addition, (meth) acrylic acid ester means acrylic acid ester and / or methacrylic acid ester.

  The acrylic polymer is preferably a copolymer of the (meth) acrylic acid ester or a derivative thereof and another monomer component in order to control adhesiveness, cohesive force and the like. Examples of the other monomer include vinyl acetate, acrylonitrile, styrene, methyl methacrylate, methyl acrylate, isobornyl acrylate, stearyl acrylate, and the like. The said other monomer can use 1 type (s) or 2 or more types.

  The amount of the other monomer used is preferably 1 to 30% by weight, more preferably 5 to 20% by weight, based on all monomer components of the acrylic polymer. By using in this range, the balance between adhesiveness and cohesiveness can be improved.

  Furthermore, in order to crosslink the acrylic polymer, a functional group-containing monomer can be used as a monomer component as necessary. The functional group-containing monomer is, for example, a monomer having a polymerizable double bond and a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, or an epoxy group in the molecule, preferably a hydroxyl group. A group-containing monomer, a carboxyl group-containing monomer, etc. can be used. Specifically, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, methacrylic acid, acrylic acid, itaconic acid, dimethylaminoethyl methacrylate, dimethylamino Examples thereof include acrylate, acrylamide, N-methylol acrylamide, glycidyl methacrylate and maleic anhydride. These functional group-containing monomers may be used alone or in combination of two or more. The amount of the functional group-containing monomer used is preferably 1 to 30% by weight, more preferably 5 to 15% by weight, based on all monomer components of the acrylic polymer.

  The acrylic polymer can be obtained by polymerizing the single monomer or a mixture of two or more monomers. The polymerization can be performed by any system such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization and the like.

  As the ultraviolet curable material, at least a polyfunctional thiol compound is used. Thereby, as mentioned above, since the polymerization inhibition by oxygen at the time of ultraviolet irradiation can be suppressed and the residual monomer can be reduced, the adhesive residue at the time of peeling of the adhesive film can be reduced.

  As the polyfunctional thiol compound, a compound having two or more thiol groups in one molecule can be used, for example, trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, Examples include dipentaerythritol hexa-3-mercaptopropionate and tetraethylene glycol bis-3-mercaptopropionate. The said polyfunctional thiol compound can use 1 type (s) or 2 or more types.

  As for the usage-amount of the said polyfunctional thiol compound, 10-40 weight part is preferable with respect to 100 weight part of said acrylic polymers, More preferably, it is 15-30 weight part. By using in this range, the balance between the adhesiveness and peelability of the pressure-sensitive adhesive layer can be improved.

  The UV curable material further contains one or more of (meth) acrylic or urethane acrylate monomers, prepolymers, oligomers and polymers having a reactive double bond in order to adjust the peelability. It may be. As for the usage-amount of the monomer etc. which have the said reactive double bond, 5-15 weight part is preferable with respect to 100 weight part of said acrylic polymers.

  Examples of the ultraviolet polymerization initiator include acetophenones, benzophenones, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, thiuram compounds, and fluoroamine compounds. Can be used. These ultraviolet polymerization initiators can be used alone or in combination of two or more. Although the usage-amount of the said ultraviolet polymerization initiator is not specifically limited, Usually, it is about 1-15 weight part with respect to 100 weight part of said ultraviolet curable materials.

  The pressure-sensitive adhesive layer preferably further contains a thermosetting material. The adhesive film can be easily peeled by somewhat increasing the cohesiveness of the acrylic polymer by curing the thermosetting material with heat.

  As said thermosetting material, an organic polyvalent isocyanate compound, an organic polyvalent epoxy compound, an organic polyvalent imine compound, a metal chelate compound, etc. can be used.

  Examples of the organic polyvalent isocyanate compound include aromatic organic polyvalent isocyanate compounds, aliphatic organic polyvalent isocyanate compounds, alicyclic organic polyvalent isocyanate compounds, and trimers of these polyvalent isocyanate compounds. And terminal isocyanate urethane prepolymers obtained by reacting these polyvalent isocyanate compounds and polyol compounds. Specific examples of the organic polyvalent isocyanate compound include, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate, Diphenylmethane-4,4′-diisocyanate, diphenylmethane-2,4′-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-di Examples thereof include isocyanate, dicyclohexylmethane-2,4′-diisocyanate, and lysine isocyanate.

  Examples of the organic polyvalent epoxy compound include bisphenol A type epoxy compound, bisphenol F type epoxy compound, 1,3-bis (N, N diglycidylaminomethyl) benzene, 1,3-bis (N, N diglycidyl). Aminomethyl) toluene, N, N, N ′, N′-tetraglycidyl-4,4-diamidylphenylmethane and the like.

  Examples of the organic polyvalent imine compound include N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri -Β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, N, N′-toluene-2,4-bis (1-aziridinecarboxyamide) triethylenemelamine, etc. It is done.

  Examples of the metal chelate compound include titanium acetylacetonate, diisopropoxytitanium bis (acetylacetonate), aluminum tris (ethylacetylacetonate), zirconium tetraacetylacetonate and the like.

  The amount of the thermosetting material used is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the acrylic polymer. By using in this range, the balance between the adhesiveness and peelability of the pressure-sensitive adhesive layer can be improved.

  Although the thickness of the said adhesive layer can be suitably set according to kinds, such as a semiconductor wafer, Usually, it is 2-200 micrometers, Preferably it is 100-200 micrometers. By setting it as the thickness of this range, moderate adhesiveness can be provided to the said adhesive layer. If the total thickness of the pressure-sensitive adhesive layer is within the above range, the pressure-sensitive adhesive layer may be formed of a plurality of layers.

(Base material)
As the substrate, a resin film capable of transmitting ultraviolet rays can be used. For example, polyester resin, polycarbonate resin, polyacrylate resin, alicyclic polyolefin resin, polystyrene resin, polychlorinated resin A resin material such as a vinyl resin, a polyvinyl acetate resin, a polyether sulfone resin, or a triacetyl cellulose resin that has been processed into a film or sheet can be used. Examples of methods for processing the resin material into a film or sheet include extrusion molding, calender molding, compression molding, injection molding, and a method in which the resin material is dissolved in a solvent and cast. The thickness of the substrate is usually about 10 to 500 μm.

  Additives such as antioxidants, flame retardants, heat resistance inhibitors, ultraviolet absorbers, lubricants and antistatic agents may be added to the substrate. Furthermore, in order to improve the adhesiveness with the pressure-sensitive adhesive layer provided thereon, an easy-adhesive layer (for example, a primer layer) is provided on the surface of the substrate, or a surface such as corona treatment, UV ozone treatment, plasma treatment, etc. Processing may be performed.

  It is preferable that the adhesive force prescribed | regulated by JISZ0237 after the ultraviolet irradiation of the ultraviolet curable adhesive film of this invention is 0.5 N / 10mm or less. This is because the adhesive film can be easily peeled off from a semiconductor wafer or the like if the adhesive strength after ultraviolet irradiation is 0.5 N / 10 mm or less. Control of the adhesive force can be easily performed by adjusting the type and blending amount of the above-mentioned pressure-sensitive adhesive layer forming material.

  On the other hand, it is preferable that the adhesive force prescribed | regulated by JISZ0237 before the ultraviolet irradiation of the ultraviolet curable adhesive film of this invention exceeds 0.5 N / 10mm. If the adhesive strength before UV irradiation exceeds 0.5 N / 10 mm, sufficient adhesion to semiconductor wafers can be obtained, so grinding used to wash away grinding scraps of semiconductor wafers and to cool them during grinding Water can be prevented from entering the surface of a semiconductor wafer or the like.

  Next, the manufacturing method of the ultraviolet curable adhesive film of this invention is demonstrated based on drawing. However, the description which overlaps with description of the ultraviolet curable adhesive film of this invention mentioned above is abbreviate | omitted. FIG. 1 is a schematic cross-sectional view showing an example of the ultraviolet curable adhesive film of the present invention.

  As shown in FIG. 1, an example of the method for producing the ultraviolet curable pressure-sensitive adhesive film of the present invention includes a step of forming a pressure-sensitive adhesive layer 12 by applying a pressure-sensitive adhesive solution on a release film 11 and drying it. And a step of laminating the base film 13 on the pressure-sensitive adhesive layer 12.

(Preparation of adhesive solution)
First, after mixing the above-mentioned adhesive material, a polymerization initiator, and a solvent, the monomer component is polymerized under predetermined conditions to prepare an adhesive material solution. Examples of the polymerization initiator include azobisisobutyronitrile, benzoyl peroxide, t-butyl hydroperoxide, methyl ethyl ketone peroxide, cumene peroxide, cyclohexane peroxide, and the like. Moreover, toluene, ethyl acetate, methyl ethyl ketone, etc. can be used as said solvent.

  Next, the above-mentioned ultraviolet curable material, an ultraviolet polymerization initiator, and, if necessary, a thermosetting material are mixed with the above-mentioned adhesive material solution to prepare an adhesive solution.

(Formation of adhesive layer)
First, the release film 11 is prepared. As the release film 11, for example, a film in which a release layer 11a is formed with a silicone resin or the like on one side of a film such as polyethylene terephthalate, polyethylene naphthalate, polyethylene, or polypropylene can be used. The thickness of the release film 11 including the release layer 11a is not particularly limited, but is usually 15 to 100 μm.

  Next, as shown in FIG. 1, the pressure-sensitive adhesive layer 12 is formed on the release layer 11 a of the release film 11 by applying the pressure-sensitive adhesive solution and drying it. The method of applying the pressure-sensitive adhesive solution is not particularly limited. For example, a coating method such as roll coating, die coating, air knife coating, blade coating, spin coating, reverse coating, gravure coating, knife coating, or gravure printing, screen printing, offset. Printing methods such as printing and ink jet printing can be used.

(Preparation of adhesive film)
Finally, the adhesive film 10 is produced by sticking the base film 13 on the adhesive layer 12.

  When the produced adhesive film 10 is bonded to a semiconductor wafer or the like, the release film 11 is peeled off, and then the adhesive layer 12 side of the adhesive film 10 is bonded to the surface of the semiconductor wafer or the like. Subsequently, after grinding the back surface of the semiconductor wafer or the like to a predetermined thickness, the adhesive film 10 is irradiated with ultraviolet rays to reduce the adhesive force of the adhesive layer 12, and finally the adhesive film 10 is peeled from the semiconductor wafer or the like.

  Although the example which applied the adhesive solution on the release film 11 was demonstrated in the said example, after applying an adhesive solution on the base film 13, you may bond the release film 11 together.

  Moreover, although the example which used the release film 11 was demonstrated in the said example, you may use as an adhesive film in the state which apply | coated the adhesive solution on the base film 13. FIG. In this case, in order to improve the handleability of the pressure-sensitive adhesive film, a release layer is formed on the surface of the base film on the side where the pressure-sensitive adhesive layer is not formed, and the tape is wound and stored. Is preferred.

  Further, in order to improve the followability to unevenness such as a circuit pattern formed on a semiconductor wafer or the like, an intermediate layer may be formed on the surface of the pressure-sensitive adhesive layer 12 on the side not in contact with the base film 13 Good. The material for forming the intermediate layer is not particularly limited, and a flexible material that can absorb the unevenness can be used. For example, an organic elastic material or a thermoplastic resin can be used. The method for forming the intermediate layer includes a so-called sequential multi-layer coating method in which an adhesive layer formed by coating is dried and then an intermediate layer material is coated on the pressure-sensitive adhesive layer and dried, and a pressure-sensitive adhesive formed by coating There is a so-called simultaneous multi-layer coating method in which an intermediate layer material is coated on the pressure-sensitive adhesive layer and dried before the layer is dried. Any method may be used. Further, the thickness of the intermediate layer is not particularly limited, and can be appropriately set according to the height of the unevenness.

  Hereinafter, the present invention will be described in detail based on examples. However, the present invention is not limited to the following examples. Unless otherwise indicated, in the following, “part” means “part by weight”.

Example 1
As a monomer component of the adhesive material, 65 parts of butyl acrylate, 10 parts of methyl methacrylate, 25 parts of hydroxyethyl acrylate, 0.4 part of azobisisobutyronitrile as a polymerization initiator, and acetic acid as a solvent 40 parts of ethyl and 60 parts of toluene are mixed and subjected to a polymerization reaction at 65 ° C. for 10 hours in a nitrogen atmosphere, and a (meth) acrylic acid ester having a glass transition temperature of −35 ° C. and a weight average molecular weight of 700,000 is obtained. A polymer solution of the polymer was prepared.

  For 100 parts of the polymer solution, 10 parts of pentaerythritol tetrakis-3-mercaptopropionate (“PEMP” manufactured by Sakai Chemical Co., Ltd.), which is a polyfunctional thiol compound, as an ultraviolet curable material, and an ultraviolet polymerization initiator, 2-methyl-1--4-[(methylthio) phenyl] -2-morpholinopropan-1-one (“Irgacure 907” manufactured by Ciba Japan) and a polyisocyanate material (Nippon Polyurethane Co., Ltd.) as a thermosetting material An adhesive solution was prepared by mixing 1 part of a 75 wt% ethyl acetate solution of “Coronate L” produced by the manufacturer.

  Further, as a release film, a polyethylene terephthalate (PET) film (thickness 38 μm) having a release layer formed by coating a silicone resin on one side was prepared.

  Next, the pressure-sensitive adhesive solution is applied to the surface of the PET film having a release layer formed thereon using a die coater so that the coating thickness after drying is 150 μm, and dried at 100 ° C. for 1 minute. An adhesive layer was formed. Thereafter, a polypropylene film having a thickness of 100 μm (“SP80” manufactured by JSR) was bonded as a base film on the pressure-sensitive adhesive layer, and then subjected to aging treatment at 40 ° C. for 72 hours. A film was prepared. The adhesive film of this example is a so-called blend type adhesive film.

  In this example, the amount of the polyfunctional thiol compound (pentaerythritol tetrakis-3-mercaptopropionate) used relative to 100 parts of the acrylic polymer solid [(meth) acrylic acid ester copolymer] is 20 parts.

(Example 2)
The polyfunctional thiol compound pentaerythritol tetrakis-3-mercaptopropionate is used in an amount of 10 parts with respect to 100 parts of the polymer solution, and dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd.) is used as an ultraviolet curable material. A pressure-sensitive adhesive film of this example was produced in the same manner as in Example 1 except that 5 parts of “KAYARAD DPHA” manufactured by the manufacturer were added.

  In this example, the amount of the polyfunctional thiol compound (pentaerythritol tetrakis-3-mercaptopropionate) used relative to 100 parts of the acrylic polymer solid [(meth) acrylic acid ester copolymer] is 20 parts.

(Example 3)
The polyfunctional thiol compound pentaerythritol tetrakis-3-mercaptopropionate is used in an amount of 10 parts with respect to 100 parts of the polymer solution, and dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd.) is used as an ultraviolet curable material. A pressure-sensitive adhesive film of this example was produced in the same manner as in Example 1 except that 2.5 parts of “KAYARAD DPHA” (manufactured by Kay) was added.

  In this example, the amount of the polyfunctional thiol compound (pentaerythritol tetrakis-3-mercaptopropionate) used relative to 100 parts of the acrylic polymer solid [(meth) acrylic acid ester copolymer] is 20 parts.

Example 4
The polyfunctional thiol compound pentaerythritol tetrakis-3-mercaptopropionate is used in an amount of 10 parts with respect to 100 parts of the polymer solution, and dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd.) is used as an ultraviolet curable material. A pressure-sensitive adhesive film of this example was produced in the same manner as in Example 1 except that 7.5 parts of “KAYARAD DPHA” (manufactured by Kay) was added.

  In this example, the amount of the polyfunctional thiol compound (pentaerythritol tetrakis-3-mercaptopropionate) used relative to 100 parts of the acrylic polymer solid [(meth) acrylic acid ester copolymer] is 20 parts.

(Comparative Example 1)
The polyfunctional thiol compound pentaerythritol tetrakis-3-mercaptopropionate is used in an amount of 0 part with respect to 100 parts of the polymer solution, and dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.) is used as an ultraviolet curable material. An adhesive film of this comparative example was produced in the same manner as in Example 1 except that 10 parts of “KAYARAD DPHA”) was added.

(Comparative Example 2)
As a monomer component of the adhesive material, 65 parts of butyl acrylate, 10 parts of methyl methacrylate, 25 parts of hydroxyethyl acrylate, 10 parts of methacryloyloxyethyl isocyanate, and azobisisobutyronitrile as a polymerization initiator were added in an amount of 0. 4 parts, 40 parts of ethyl acetate as a solvent, and 60 parts of toluene are mixed, and a polymerization reaction is performed at 65 ° C. for 10 hours under a nitrogen atmosphere. The glass transition temperature is −30 ° C., and the weight average molecular weight is 700,000. A polymer solution of a (meth) acrylic acid ester copolymer having an unsaturated bond group at the terminal was prepared.

  2 parts of 2-methyl-1--4-[(methylthio) phenyl] -2-morpholinopropan-1-one (“Irgacure 907” manufactured by Ciba Japan) as an ultraviolet polymerization initiator with respect to 100 parts of the polymer solution Then, as a thermosetting material, 1 part of a polyisocyanate material (75% by weight ethyl acetate solution of “Coronate L” manufactured by Nippon Polyurethane Co., Ltd.) was mixed to prepare an adhesive solution.

  Further, as a release film, a polyethylene terephthalate (PET) film (thickness 38 μm) having a release layer formed by coating a silicone resin on one side was prepared.

  Next, the pressure-sensitive adhesive solution is applied to the surface of the PET film having a release layer formed thereon using a die coater so that the coating thickness after drying is 150 μm, and dried at 100 ° C. for 1 minute. An adhesive layer was formed. Thereafter, a polypropylene film having a thickness of 100 μm (“SP80” manufactured by JSR) was bonded as a base film on the pressure-sensitive adhesive layer, and then subjected to an aging treatment at 40 ° C. for 72 hours. An adhesive film was prepared. The adhesive film of this comparative example is a so-called adduct type adhesive film.

  Then, the characteristic of the adhesive film of Examples 1-4 and Comparative Examples 1 and 2 was evaluated as follows.

<Initial adhesive strength>
The release film was peeled from the adhesive film, the adhesive surface was bonded to a silicon wafer, and the adhesive force of the adhesive film to the silicon wafer was measured according to JIS Z 0237. The results are shown in Table 1.

<Adhesive strength after UV irradiation>
After releasing the release film from the adhesive film and bonding the adhesive surface to the silicon wafer, the film was irradiated with ultraviolet rays under the conditions of illuminance: 220 mW / cm ² and light quantity: 440 mJ / cm ² . Thereafter, the adhesive force of the adhesive film to the silicon wafer was measured according to JIS Z 0237. The results are shown in Table 1.

<Adhesive residue>
The release film is peeled off from the adhesive film, and the probe tack tester is used with a probe tack tester under the conditions of an adhesive area: a circular area with a diameter of 5.0 mm, a load: 500 gf, a probe speed: 10 mm / second, and a pressure bonding time: 0.1 second The force was measured. The results are shown in Table 1. The larger the probe tack force, the greater the tack feeling and the greater the amount of adhesive residue.

  From Table 1, it can be seen that in the adhesive films of Examples 1 to 4, the measured value of the probe tack force is small and the adhesive residue is small. Moreover, while the adhesive film of Examples 1-4 has sufficient initial adhesive force, it can make the adhesive force after ultraviolet irradiation 0.5 N / 10mm or less. Therefore, it can be seen that the adhesive films of Examples 1 to 4 have the same characteristics as the adduct adhesive film of Comparative Example 2. On the other hand, in Comparative Example 1 in which the polyfunctional thiol compound was not used as the ultraviolet curable material, it was found that the measured value of the probe tack force was large and the adhesive residue was large.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive force is large, it is excellent in the peelability after ultraviolet irradiation, and it can provide the ultraviolet curable adhesive film with few adhesive residues at the time of peeling.

DESCRIPTION OF SYMBOLS 10 Adhesive film 11 Release film 11a Release layer 12 Adhesive layer 13 Base film

Claims (6)

A UV curable adhesive film comprising a substrate and an adhesive layer formed on one main surface of the substrate,
The adhesive layer includes an adhesive material, an ultraviolet curable material, and an ultraviolet polymerization initiator,
The ultraviolet curable adhesive film, wherein the ultraviolet curable material contains a polyfunctional thiol compound.   The ultraviolet curable adhesive film according to claim 1, wherein the adhesive material is an acrylic polymer.   The ultraviolet curable adhesive film according to claim 1, wherein the polyfunctional thiol compound has two or more thiol groups in one molecule.   The ultraviolet-sensitive adhesive film according to claim 2 or 3, wherein the pressure-sensitive adhesive layer contains 10 to 40 parts by weight of the polyfunctional thiol compound with respect to 100 parts by weight of the acrylic polymer.   The said adhesive layer is an ultraviolet curable adhesive film in any one of Claims 1-4 further containing a thermosetting material.   The ultraviolet curable pressure-sensitive adhesive film according to any one of claims 1 to 5, wherein the adhesive strength defined by JIS Z 0237 after ultraviolet irradiation is 0.5 N / 10 mm or less.

Images