JPWO2020137980A1 - Adhesive tape - Google Patents

Abstract

It is an object of the present invention to provide an adhesive tape that protects an adherend and can be peeled off without adhesive residue even when used in a process involving a high temperature treatment reaching 260 ° C. The present invention is an adhesive tape having a base film and an ultraviolet curable pressure-sensitive adhesive layer laminated on one side of the base film, and 405 nm ultraviolet rays are applied to the surface of the adhesive tape on the base film side at 3000 mJ. The gel content of the ultraviolet curable adhesive layer after irradiation at / cm2 is 90% or more, and the surface of the adhesive tape on the base film side is irradiated with ultraviolet rays of 405 nm at 3000 mJ / cm2. An adhesive tape having an Et (270) value of 1.0 × 107 Pa or more, where Et (X) is the tensile elasticity at X ° C.

Description

The present invention relates to an adhesive tape.

In the semiconductor chip manufacturing process, adhesive tapes are used to facilitate handling of wafers and semiconductor chips during processing and to prevent damage. For example, when a thick film wafer cut out from a high-purity silicon single crystal or the like is ground to a predetermined thickness to obtain a thin film wafer, grinding is performed after attaching an adhesive tape to the thick film wafer.

The adhesive composition used for such an adhesive tape has high adhesiveness enough to firmly fix an adherend such as a wafer or a semiconductor chip during a processing process, and is covered with a wafer or a semiconductor chip after the process is completed. It is required that the wafer can be peeled off without damaging it (hereinafter, also referred to as "high adhesive easy peeling").
As an adhesive composition that realizes high adhesiveness and easy peeling, Patent Document 1 discloses an adhesive tape using a photocurable adhesive that is cured by irradiating with light such as ultraviolet rays to reduce the adhesive strength. .. By using a photocurable pressure-sensitive adhesive as the pressure-sensitive adhesive, the adherend can be reliably fixed during the processing process and can be easily peeled off by irradiating with ultraviolet rays or the like.

Japanese Unexamined Patent Publication No. 5-32946

In recent years, with the thinning and miniaturization of semiconductor products, semiconductor devices in which a large number of semiconductor chips are laminated on a wafer have come to be manufactured. In the manufacture of a semiconductor device in which a large number of semiconductor chips are laminated, the semiconductor chip is fixed on the wafer or semiconductor chip by a thermocompression bonding step while the wafer or semiconductor chip is protected by an adhesive tape.
Since the heat-bonding bonding requires a high temperature of 260 ° C., which exceeds the conventional high-temperature treatment, the present inventors cannot withstand the heat of the high-temperature treatment even if the adhesive tape uses a conventional curable adhesive. It was found that the base film of No. 1 shrinks, and the shrinkage pulls the adhesive layer, so that the adhesive tape peels off. Further, in thermocompression bonding, pressure is applied in addition to high temperature, so that the adhesion of the pressure-sensitive adhesive tends to be enhanced and adhesive residue is likely to occur. Further, in wafers where the thermocompression bonding step is performed, bumps having large irregularities are often formed on the surface to which the adhesive tape is attached, and if the adhesive gets caught in the inner part of the irregularities, the adhesive is peeled off. It will be torn and the adhesive will remain.

It is an object of the present invention to provide an adhesive tape that protects an adherend and can be peeled off without adhesive residue even when used in a process involving a high temperature treatment reaching 260 ° C.

The present invention is an adhesive tape having a base film and an ultraviolet curable pressure-sensitive adhesive layer laminated on one side of the base film, and 405 nm ultraviolet rays are applied to the surface of the adhesive tape on the base film side at 3000 mJ. The gel content of the ultraviolet curable adhesive layer after irradiation with / cm ² is 90% or more, and the adhesive after irradiating the surface of the adhesive tape on the base film side with ultraviolet rays of 405 nm at 3000 mJ / cm ^2. when the tensile elastic modulus at X ° C. tapes was Et (X), is the value of Et (270) is 1.0 × ¹⁰ 7 Pa or more, an adhesive tape.
The present invention will be described in detail below.

The adhesive tape of the present invention has an ultraviolet curable adhesive layer laminated on one side of the base film.
Since the adhesive tape has an ultraviolet curable adhesive layer, it can be attached to the adherend with sufficient adhesive force to protect the adherend, and the ultraviolet curable adhesive layer is cured after the adhesive is applied to the high temperature. The adherend can be protected even when the treatment is performed. Further, after the protection becomes unnecessary, the adhesive tape can be easily peeled off without adhesive residue.

In the adhesive tape of the present invention, the gel content of the ultraviolet curable adhesive layer after irradiating the surface of the adhesive tape on the base film side with ultraviolet rays of 405 nm at 3000 mJ / cm ^{2 is 90% or more.}
Since the gel fraction of the UV-curable adhesive layer after UV irradiation is 90% or more, it is difficult for the adhesion to proceed even at high temperatures, so the adhesive tape is peeled off without adhesive residue after protection is no longer required. can do. In addition, the chemical resistance of the adhesive tape can be improved. Further, if the surface of the base film side can be irradiated with ultraviolet rays to cure the ultraviolet curable pressure-sensitive adhesive layer, the UV-curable pressure-sensitive adhesive layer can be cured after the adhesive tape is attached to the adherend. It will be possible. From the viewpoint of further improving the adhesion enhancement property and the chemical resistance of the adhesive tape, the gel fraction of the ultraviolet curable pressure-sensitive adhesive layer after irradiation with ultraviolet rays is preferably 93% or more, preferably 95% or more. More preferably, it is more preferably 97% or more.
The gel fraction of the ultraviolet curable pressure-sensitive adhesive layer after irradiation with ultraviolet rays is usually 100% or less.
When the adhesive tape of the present invention has a structure in which another layer such as an adhesive layer is laminated on another surface of the base film, the base film side is an ultraviolet curable type of the base film. Refers to the surface opposite to the surface on which the adhesive layer is laminated.

In the adhesive tape of the present invention, when the tensile elastic modulus at X ° C. of the adhesive tape after irradiating the surface of the adhesive tape on the base film side with the ultraviolet rays of 405 nm at 3000 mJ / cm ^{2 is Et (X).} the value of Et (270) is that 1.0 × ¹⁰ 7 Pa or higher.
Since the adhesive tape after irradiation with ultraviolet rays has a tensile elastic modulus in the above range at 270 ° C., the adhesive tape can be made into an adhesive tape having excellent heat resistance, and the adhesive tape softens even after high temperature treatment reaching 260 ° C. , It becomes difficult to shrink, and it is possible to suppress unintentional peeling of the adhesive tape. The preferred lower limit of Et (270) is 3.0 × 10 ⁷ Pa, the more preferable lower limit is 5.0 × 10 ⁷ Pa, and the more preferable lower limit is 1.0 × 10 ⁸ Pa. The upper limit of Et (270) is not particularly limited, but is preferably ^{1.0 × 10 9 Pa from the viewpoint of handleability of the adhesive tape.}
The tensile elastic modulus of the adhesive tape can be measured by the following method.
The ultraviolet curable pressure-sensitive adhesive layer is cured by irradiating the ultraviolet-curable pressure-sensitive adhesive layer with ultraviolet rays of 405 nm from the surface on the base film side so that the integrated intensity becomes 3000 mJ / cm ^2. Next, a 5 mm × 35 mm test piece is produced by punching with a punching blade so that the long side is the same as the flow direction at the time of tape manufacturing. The obtained test piece is immersed in liquid nitrogen, cooled to -50 ° C, and then heated at a constant rate using a viscoelastic spectrometer (DVA-200, manufactured by IT Measurement Control Co., Ltd., or an equivalent product thereof). The tensile elastic modulus is measured by raising the temperature to 300 ° C. under the conditions of a tensile mode of 10 ° C./min and a frequency of 10 Hz. The value of the tensile elastic modulus (E') at the temperature X ° C. at this time is defined as Et (X). That is, the value of the tensile elastic modulus (E') at a temperature of 270 ° C. is Et (270).

The adhesive tape of the present invention preferably has an Et (270) / Et (200) value of 0.1 or more.
Since the difference between the tensile elastic modulus at 270 ° C and the tensile elastic modulus at 200 ° C of the adhesive tape after irradiation with ultraviolet rays is small, the adhesive tape having better heat resistance can be obtained, and the adhesive tape can be more unintentionally peeled off. It can be suppressed. From the viewpoint of further suppressing the peeling, the value of Et (270) / Et (200) is more preferably 0.2 or more, further preferably 0.3 or more, and 0.5 or more. Is particularly preferred. The upper limit of the value of Et (270) / Et (200) is not particularly limited, and the closer it is to 1, the better it is, but it is usually 1 or less, preferably less than 0.8.

In the adhesive tape of the present invention, the surface of the adhesive tape on the base film side is ^{irradiated with ultraviolet rays of 405 nm at 3000 mJ / cm 2} and then heated from 25 ° C. to 280 ° C. at a rate of 5 ° C./min to raise the temperature. It is preferable that the weight loss rate when held for 10 minutes after warming is 5% or less.
Since the weight loss at a high temperature of 280 ° C. is small, that is, it is difficult for thermal decomposition to occur at a high temperature, the amount of outgas generated by the thermal decomposition is reduced, and the outgas collected at the interface between the adherend and the adhesive tape becomes the starting point. Can be prevented from peeling off. From the viewpoint of suppressing peeling under high temperature, the weight reduction rate is more preferably 4% or less, further preferably 3% or less, and usually 0% or more.
The weight loss rate can be measured by the following method.
The ultraviolet curable pressure-sensitive adhesive layer is cured by irradiating the ultraviolet-curable pressure-sensitive adhesive layer with ultraviolet rays of 405 nm from the surface on the base film side so that the integrated intensity becomes 3000 mJ / cm ^2. Next, the adhesive tape is punched into a circle having a diameter of 5 mm to prepare a measurement sample. The weight of the obtained measurement sample is measured, and the measurement is performed using a differential thermal weight simultaneous measuring device (TG-DTA; STA7200, manufactured by Hitachi High-Tech Science Co., Ltd., or an equivalent product thereof). The temperature rise rate is 5 ° C./min, the temperature is raised from 25 ° C. to 280 ° C., and the weight of the measurement sample is measured after holding the temperature at 280 ° C. for 10 minutes. The weight loss rate can be calculated from the weight before and after heating.

The base film preferably has an ultraviolet transmittance of 1% or more at 405 nm.
When the UV transmittance of the base film at 405 nm is 1% or more, the UV curable pressure-sensitive adhesive layer can be cured through the base film, and the gel fraction of the UV-curable pressure-sensitive adhesive layer after the above-mentioned UV irradiation. It becomes easier to adjust. As a result, it is possible to suppress the adhesive residue on the adherend due to the enhanced adhesion. The ultraviolet transmittance is more preferably 10% or more, further preferably 50% or more, and particularly preferably 70% or more. When the ultraviolet transmittance is at least these lower limits, the ultraviolet curable pressure-sensitive adhesive layer can be sufficiently cured without using a photosensitizer. The upper limit of the ultraviolet transmittance is not particularly limited, and the higher the upper limit, the better, usually 100% or less.
The ultraviolet transmittance can be measured using a spectrophotometer (U-3900, manufactured by Hitachi, Ltd., or an equivalent product thereof). More specifically, it is possible to measure at a scan speed of 300 nm / min and a slit spacing of 4 nm in a region of 800 to 200 nm, and to measure the transmittance at 405 nm.

The substrate film is, when the tensile modulus at X ° C. and Ef (X), it is preferable the value of Ef (270) is 5.0 × ¹⁰ 7 Pa or higher.
When the tensile elastic modulus of the base film at 270 ° C. is within the above range, it is possible to obtain an adhesive tape having more excellent heat resistance, and it is possible to suppress peeling due to heat shrinkage or softening of the base film during high temperature treatment. Can be done. The more preferable lower limit of Ef (270) is 1.0 × 10 ⁸ Pa, the more preferable lower limit is 5.0 × 10 ⁸ Pa, and the particularly preferable lower limit is 1.0 × 10 ⁹ Pa. The upper limit of Ef (270) is not particularly limited, but is preferably ^{1.0 × 10 10 Pa from the viewpoint of handleability of the adhesive tape.}
The tensile elastic modulus of the base film can be measured by the same method as the tensile elastic modulus of the adhesive tape.

The base film is not particularly limited as long as the obtained adhesive tape satisfies the tensile elastic modulus and gel fraction in the above ranges, but since it is excellent in heat resistance and strength, the base film can be made of amide, imide, ether and the like. It is preferable to contain a resin having at least one selected from the group consisting of ketones in the main chain skeleton of the repeating unit.
Examples of the resin having at least one selected from the group consisting of amides, imides, ethers and ketones in the main chain skeleton of the repeating unit include polyamides, polyimides, polyethers and polyketones. Among them, the base film preferably contains a polyamide resin because it is excellent in heat resistance and strength, and is also excellent in ultraviolet transmittance. Therefore, it is a long-chain alkyl group having 4 or more and 12 or less carbon atoms or an aromatic. It is more preferable to contain a polyamide resin having the group in the main chain skeleton of the repeating unit.
Examples of the polyamide resin having a long-chain alkyl group having 4 or more and 12 or less carbon atoms or an aromatic in the main chain skeleton of a repeating unit include nylon 9T and nylon 6T.

The thickness of the base film is not particularly limited, but a preferable lower limit is 25 μm, a more preferable lower limit is 50 μm, a preferable upper limit is 250 μm, and a more preferable upper limit is 125 μm. When the base film is in this range, it can be an adhesive tape having excellent handleability.

The pressure-sensitive adhesive constituting the UV-curable pressure-sensitive adhesive layer is not particularly limited as long as it is a UV-curable type, but for example, a UV-curable adhesive containing a polymerizable polymer as a main component and a UV polymerization initiator as a polymerization initiator. Agents are mentioned. Examples of the polymerizable polymer include (meth) acrylic polymers and urethane acrylate polymers. Among them, a (meth) acrylic polymer is preferable because it easily satisfies the gel fraction and Et (270), and a (meth) acrylic acid alkyl ester type having a radically polymerizable unsaturated bond in the molecule. It is more preferable that it is a polymerizable polymer of.
The (meth) acrylic acid alkyl ester-based polymerizable polymer is, for example, a functional group and a radical that react with the above-mentioned functional group in the molecule by synthesizing a (meth) acrylic polymer having a functional group in the molecule in advance. It can be obtained by reacting with a compound having a polymerizable unsaturated bond. Hereinafter, the "(meth) acrylic polymer having a functional group in the molecule" is referred to as a "functional group-containing (meth) acrylic polymer", and is referred to as a "functional group that reacts with the above functional group in the molecule". A compound having a radically polymerizable unsaturated bond is referred to as a "functional group-containing unsaturated compound".

The functional group-containing (meth) acrylic polymer mainly comprises an acrylic acid alkyl ester and / or a methacrylate alkyl ester in which the number of carbon atoms of the alkyl group is usually in the range of 2 to 18, and the functional group-containing monomer and the functional group-containing monomer are used as the main monomer. Further, if necessary, it can be obtained by copolymerizing these with another copolymerizable monomer for modification by a conventional method. The weight average molecular weight of the functional group-containing (meth) acrylic polymer is usually about 200,000 to 2,000,000. In the present specification, the weight average molecular weight can be usually determined by the GPC method. For example, THF is used as an eluent at 40 ° C., and HSPgel HR MB-M 6.0 × 150 mm (manufactured by Waters) is used as a column. Can be determined by the polystyrene standard.

Examples of the functional group-containing monomer include a carboxy group-containing monomer, a hydroxyl group-containing monomer, an epoxy group-containing monomer, an isocyanate group-containing monomer, and an amino group-containing monomer. Examples of the carboxy group-containing monomer include acrylic acid and methacrylic acid. Examples of the hydroxyl group-containing monomer include hydroxyethyl acrylate and hydroxyethyl methacrylate. Examples of the epoxy group-containing monomer include glycidyl acrylate and glycidyl methacrylate. Examples of the isocyanate group-containing monomer include ethyl isocyanate, ethyl methacrylate and the like. Examples of the amino group-containing monomer include aminoethyl acrylate and aminoethyl methacrylate.

Examples of the other copolymerizable monomer for modification include various monomers used in general (meth) acrylic polymers such as vinyl acetate, acrylonitrile, and styrene.

As the functional group-containing unsaturated compound to be reacted with the functional group-containing (meth) acrylic polymer, the same one as the above-mentioned functional group-containing monomer is used depending on the functional group of the functional group-containing (meth) acrylic polymer. can. For example, when the functional group of the functional group-containing (meth) acrylic polymer is a carboxy group, an epoxy group-containing monomer or an isocyanate group-containing monomer is used. When the functional group is a hydroxyl group, an isocyanate group-containing monomer is used. When the functional group is an epoxy group, a carboxy group-containing monomer or an amide group-containing monomer such as acrylamide is used. When the functional group is an amino group, an epoxy group-containing monomer is used.

Examples of the ultraviolet polymerization initiator include those that are activated by irradiating with ultraviolet rays having a wavelength of 200 to 410 nm. Examples of such an ultraviolet polymerization initiator include acetophenone derivative compounds, benzophenone ether compounds, ketal derivative compounds, phosphine oxide derivative compounds, bis (η5-cyclopentadienyl) titanosen derivative compounds, benzophenone, Michler ketone, and chloro. Examples thereof include thioxanthone, todecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexylphenyl ketone, 2-hydroxymethylphenylpropane and the like. Examples of the acetophenone derivative compound include methoxyacetophenone and the like. Examples of the benzoin ether compound include benzoin propyl ether and benzoin isobutyl ether. Examples of the ketal derivative compound include benzyldimethyl ketal, acetophenone diethyl ketal and the like. These ultraviolet polymerization initiators may be used alone or in combination of two or more.

The UV curable pressure-sensitive adhesive layer preferably contains a radically polymerizable polyfunctional oligomer or monomer. When the ultraviolet curable pressure-sensitive adhesive layer contains a radically polymerizable polyfunctional oligomer or monomer, the ultraviolet curability is improved.
The polyfunctional oligomer or monomer preferably has a weight average molecular weight of 10,000 or less, and more preferably, the weight average thereof so that the ultraviolet curable pressure-sensitive adhesive layer can be efficiently reticulated by irradiation with ultraviolet rays. The molecular weight is 5000 or less and the number of radically polymerizable unsaturated bonds in the molecule is 2 to 20. The weight average molecular weight can be determined by using, for example, a GPC measurement method.

The polyfunctional oligomer or monomer is, for example, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or the same methacrylate. Kind and the like. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and the same methacrylates as described above. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.

The ultraviolet curable pressure-sensitive adhesive layer may contain a cross-linking agent for the purpose of enhancing the cohesive force of the ultraviolet curable pressure-sensitive adhesive.
Examples of the above-mentioned cross-linking agent include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, aziridine-based cross-linking agents, metal chelate-based cross-linking agents and the like. Among them, an isocyanate-based cross-linking agent is preferable because the cohesive force of the ultraviolet curable pressure-sensitive adhesive is further increased.

The cross-linking agent is preferably contained in the pressure-sensitive adhesive layer in an amount of 0.1 to 20% by weight.
When the cross-linking agent is contained in the above range, the ultraviolet-curable pressure-sensitive adhesive can be appropriately cross-linked to further enhance the cohesive power of the UV-curable pressure-sensitive adhesive while maintaining high adhesive strength. From the viewpoint of further increasing the cohesive force of the ultraviolet curable pressure-sensitive adhesive while maintaining high adhesive strength, the more preferable lower limit of the content of the cross-linking agent is 0.5% by weight, and the more preferable lower limit is 1.0% by weight, more preferably. The upper limit is 15% by weight, and a more preferable upper limit is 10% by weight.

The UV curable pressure-sensitive adhesive layer preferably contains a silicone or a fluorine compound.
When the ultraviolet curable adhesive layer contains a silicone or a fluorine compound, the silicone or the fluorine compound bleeds out at the interface between the ultraviolet curable adhesive layer and the adherend, so that the adhesive tape can be easily applied after the treatment is completed. It can be peeled off without adhesive residue. Examples of the silicone or fluorine compound include silicone diacrylate and a polymer having a fluoroalkyl group (for example, a (meth) acrylic copolymer having a structural unit derived from fluoroacrylate).

The silicone or fluorine compound preferably has a functional group that can be crosslinked with the polymerizable polymer.
Since the silicone or the fluorine compound has a functional group capable of cross-linking with the polymerizable polymer, the silicone or the fluorine compound can chemically react with the polymerizable polymer and bond with the polymerizable polymer by a cross-linking agent or irradiation with ultraviolet rays. As a result, contamination due to adhesion of silicone or a fluorine compound to the adherend is suppressed.
The functional group that can be crosslinked with the polymerizable polymer is appropriately selected depending on the functional group contained in the polymerizable polymer. For example, a carboxy group, a radically polymerizable unsaturated bond, a hydroxyl group, an amide group, an isocyanate group, etc. Examples include an epoxy group. Of these, radically polymerizable unsaturated bonds are preferable. Since the silicone or fluorine compound has a radically polymerizable unsaturated bond as a functional group that can be crosslinked with the polymerizable polymer, the silicone or fluorine compound chemically reacts with the polymerizable polymer by ultraviolet irradiation to form a polymerizable polymer. Since it is taken in, contamination due to adhesion of silicone or a fluorine compound to the adherend is further suppressed.
The crosslinkable functional value of the silicone or fluorine compound is, for example, 2 to 6 valences, preferably 2 to 4 valences, and more preferably divalent.

The functional group that can be crosslinked with the polymerizable polymer is appropriately determined by the functional group contained in the polymerizable polymer. For example, the polymerizable polymer has a radically polymerizable unsaturated bond in the molecule (meth). ) In the case of an acrylic acid alkyl ester system, it is preferable to select a functional group capable of cross-linking with an unsaturated bond.
The functional group that can be crosslinked with the unsaturated bond is a functional group having an unsaturated double bond, and specifically, for example, a silicone containing a vinyl group, a (meth) acrylic group, an allyl group, a maleimide group, or the like. Select a fluorine compound or the like.

The content of the silicone or fluorine compound in the ultraviolet curable pressure-sensitive adhesive layer has a preferable lower limit of 2% by weight, a more preferable lower limit of 5% by weight, a further preferable lower limit of 10% by weight, and a preferable upper limit of 40% by weight. The preferred upper limit is 35% by weight, and the more preferable upper limit is 30% by weight.
When the content of the silicone or the fluorine compound is within the above range, the amount of outgas generated from the adhesive tape can be reduced, and the adhesive tape having more excellent heat resistance and adhesive residue prevention performance can be obtained.

The ultraviolet curable pressure-sensitive adhesive layer preferably contains urethane acrylate.
When the ultraviolet curable pressure-sensitive adhesive layer contains urethane acrylate, the flexibility of the pressure-sensitive adhesive tape is improved, and the obtained pressure-sensitive adhesive tape can be made difficult to tear.

The content of the urethane acrylate in the ultraviolet curable pressure-sensitive adhesive layer has a preferable upper limit of 20% by weight, a more preferable upper limit of 15% by weight, and a further preferable upper limit of 10% by weight. When the content of the urethane acrylate is in the above range, the adhesive tape having more excellent heat resistance and adhesive residue suppressing performance can be obtained. The lower limit of the content of the urethane acrylate is not particularly limited, but it is preferably 1% by weight from the viewpoint of making the adhesive tape more difficult to tear and suppressing adhesive residue.

The total content of the silicone or fluorine compound and the urethane acrylate in the ultraviolet curable pressure-sensitive adhesive layer is preferably 50% by weight or less.
When the total content of the silicone or fluorine compound and the urethane acrylate is within the above range, the amount of outgas generated by the thermal decomposition of these components can be suppressed, so that the outgas can be used while improving the heat resistance. Unintentional peeling can be suppressed. From the viewpoint of further suppressing the peeling, a more preferable upper limit of the total content of the silicone or fluorine compound and the urethane acrylate is 40% by weight, and a further preferable upper limit is 25% by weight.

The UV curable pressure-sensitive adhesive layer preferably contains a filler.
Since the elastic modulus is improved by containing the filler in the ultraviolet curable pressure-sensitive adhesive layer, the heat resistance of the pressure-sensitive adhesive tape can be improved. Examples of the filler material include silica, alumina, carbon black, calcium, boron, magnesium, and zirconia. Of these, silica is preferable because it has higher heat resistance.

The average particle size of the filler is not particularly limited, but a preferable lower limit is 0.06 μm, a more preferable lower limit is 0.07 μm, a preferable upper limit is 2 μm, and a more preferable upper limit is 1 μm. When the average particle size of the filler is in the above range, the dispersibility in the ultraviolet curable pressure-sensitive adhesive can be further improved.

The content of the filler in the ultraviolet curable pressure-sensitive adhesive layer is preferably 1% by weight, a more preferable lower limit of 3% by weight, a preferable upper limit of 18% by weight, and a more preferable upper limit of 12% by weight.
When the content of the filler is in the above range, the adhesive tape having more excellent heat resistance can be obtained.

The ultraviolet curable pressure-sensitive adhesive layer preferably contains a gas generating agent that generates a gas by stimulation.
When the ultraviolet curable pressure-sensitive adhesive layer contains a gas generating agent, a stimulus is given after the process to generate a gas, and a gap due to the gas is generated between the adherend and the adhesive tape. The adhesive tape can be easily peeled off.
The gas generating agent is not particularly limited, but is preferably a gas generating agent that generates a gas by light because it can be used in a high temperature treatment step. Among them, carboxylic acid compounds such as phenylacetic acid, diphenylacetic acid, and triphenylacetic acid or salts thereof, 1H-tetrazole, 5-phenyl-1H-tetrazole, and 5,5-azobis are excellent in resistance to treatments involving heating. A tetrazole compound such as -1H-tetrazole or a salt thereof is suitable. Such a gas generating agent has high heat resistance that does not decompose even at a high temperature of about 260 ° C. while generating a gas by irradiating with light such as ultraviolet rays.

The ultraviolet curable pressure-sensitive adhesive layer may contain a photosensitizer. By containing the photosensitizer, the ultraviolet curable pressure-sensitive adhesive layer can be sufficiently cured even when the ultraviolet transmittance of the base film at 405 nm is low. Further, since the photosensitizer has an effect of amplifying the stimulation of the gas generating agent by light, the gas can be released by irradiation with less light. In addition, the gas can be emitted by light in a wider wavelength region.
Examples of the photosensitizer include thioxanthone compounds such as 2,4-diethylthioxanthone, anthracene compounds such as dibutylanthracene and dipropylanthracene, and the like. In addition, 2,2-dimethoxy-1,2-diphenylethane-1-one, benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4'-bis (dimethylamino) benzophenone, 4-benzoyl -4'Methyldiphenyl sulfide and the like can also be mentioned. These photosensitizers may be used alone or in combination of two or more. The photosensitizer thermally decomposes at high temperature to generate outgas and foams an ultraviolet curable pressure-sensitive adhesive layer. Therefore, if it is used in a large amount, it may cause adhesive residue or unintended peeling. be. Therefore, it is preferable to use as little amount of the photosensitizer as possible.

The ultraviolet curable pressure-sensitive adhesive layer may contain known additives such as a plasticizer, a resin, a surfactant, and a wax. These additives may be used alone or in combination of two or more.

The storage elastic modulus G'before ultraviolet irradiation of the ultraviolet curable pressure-sensitive adhesive layer is not particularly limited, but the storage elastic modulus G'at 23 ° C. is 5.0 × 10 ³ Pa or more and 1.0 × 10 ⁵ Pa or less. It is preferable to have. When the storage elastic modulus G'at 23 ° C. of the ultraviolet curable pressure-sensitive adhesive layer before irradiation with ultraviolet rays is within the above range, the adherend can be protected with sufficient adhesive force. The storage elastic modulus G'at 23 ° C. of the ultraviolet curable pressure-sensitive adhesive layer before irradiation with ultraviolet rays can be adjusted by the type, type and amount of the pressure-sensitive adhesive constituting the ultraviolet-curable pressure-sensitive adhesive layer.
The storage elastic modulus G'of the ultraviolet curable pressure-sensitive adhesive layer at 23 ° C. before irradiation with ultraviolet rays is determined by using a viscoelastic spectrometer (for example, DVA-200, manufactured by IT Measurement Control Co., Ltd.) in a constant speed temperature rise shear mode. It can be obtained by measuring the storage elastic modulus under the conditions of a heating rate of 10 ° C./min and a frequency of 10 Hz.

The thickness of the ultraviolet curable pressure-sensitive adhesive layer is not particularly limited, but the lower limit is preferably 5 μm and the upper limit is preferably 100 μm. When the thickness of the ultraviolet curable pressure-sensitive adhesive layer is within the above range, the adherend can be protected with sufficient adhesive strength, and the adhesive residue at the time of peeling can be suppressed. From the viewpoint of further improving the adhesive strength and further suppressing the adhesive residue at the time of peeling, the more preferable lower limit of the thickness of the ultraviolet curable pressure-sensitive adhesive layer is 10 μm, and the more preferable upper limit is 60 μm.

The adhesive tape of the present invention preferably has an adhesive layer on the surface of the base film opposite to the surface on which the ultraviolet curable adhesive layer is laminated.
The adhesive tape of the present invention is a double-sided adhesive tape having an ultraviolet curable adhesive layer on one side of the base film and an adhesive layer on the other side. Since the support and the adherend can be adhered to each other, a process for manufacturing a semiconductor device using the support can be performed.

The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is not particularly limited, and examples thereof include acrylic pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, and urethane-based pressure-sensitive adhesives. Of these, acrylic or silicone adhesives are preferable because they have excellent heat resistance.
Further, as the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, the above-mentioned ultraviolet curable pressure-sensitive adhesive can also be used. By using the ultraviolet curable pressure-sensitive adhesive, the support can be held with sufficient adhesive strength, and when the support is a transparent support, the pressure-sensitive adhesive layer made of the UV-curable pressure-sensitive adhesive is applied after sticking. By curing, the support can be retained even when high temperature treatment is performed. In addition, the support can be easily removed after the support is no longer needed.

The pressure-sensitive adhesive layer preferably contains a gas generating agent that generates a gas by stimulation.
When the pressure-sensitive adhesive layer contains a gas generating agent, the support and the pressure-sensitive adhesive tape can be easily peeled off by stimulating and generating gas after the process is completed.
As the gas generator, the same gas generator as that of the ultraviolet curable pressure-sensitive adhesive layer can be used.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, but the lower limit is preferably 5 μm and the upper limit is preferably 30 μm. When the thickness of the pressure-sensitive adhesive layer is within the above range, it can be adhered to the support with sufficient adhesive strength. From the viewpoint of further enhancing the adhesive force with the support, the more preferable lower limit of the thickness of the pressure-sensitive adhesive layer is 10 μm, and the more preferable upper limit is 20 μm.

The pressure-sensitive adhesive layer may contain known additives such as a photosensitizer, a plasticizer, a resin, a surfactant, a wax, and a fine particle filler. These additives may be used alone or in combination of two or more.

The adhesive tape of the present invention may have an anchor layer between the base film and the ultraviolet curable adhesive layer.
When the anchor layer is provided between the base film and the UV curable pressure-sensitive adhesive layer, the silicone or the fluorine compound bleeds to the base film side when the UV-curable pressure-sensitive adhesive layer contains a silicone or a fluorine compound. It is possible to prevent the UV-curable pressure-sensitive adhesive layer from peeling off from the base film.

Examples of the anchor layer include an acrylic pressure-sensitive adhesive and a urethane-based pressure-sensitive adhesive. Among them, an acrylic adhesive is preferable because it has excellent anchoring performance.

The anchor layer may contain known additives such as an inorganic filler, a heat stabilizer, an antioxidant, an antistatic agent, a plasticizer, a resin, a surfactant, and a wax, if necessary. These additives may be used alone or in combination of two or more.

The thickness of the anchor layer is not particularly limited, but the preferred lower limit is 1 μm and the preferred upper limit is 30 μm. When the thickness of the anchor layer is within this range, the anchor force between the ultraviolet curable pressure-sensitive adhesive layer and the base film can be further improved. From the viewpoint of further improving the anchoring force between the ultraviolet curable pressure-sensitive adhesive layer and the base film, the more preferable lower limit of the thickness of the anchor layer is 3 μm, and the more preferable upper limit is 10 μm.

The method for producing the adhesive tape of the present invention is not particularly limited, and a conventionally known method can be used. For example, it can be produced by applying a solution of the above-mentioned UV-curable pressure-sensitive adhesive component on a film that has been subjected to a mold release treatment, drying it to form a UV-curable pressure-sensitive adhesive layer, and laminating it with a base film. .. When the adhesive tape of the present invention has the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is formed by the same method as the ultraviolet-curable pressure-sensitive adhesive layer using the solution of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer. It can be manufactured by laminating the base film on the surface opposite to the surface to which the ultraviolet curable pressure-sensitive adhesive layer is bonded.

The use of the adhesive tape of the present invention is not particularly limited, but it protects the adherend and can be peeled off without adhesive residue even when used in a harsh environment where high temperature and pressure are applied. It can be particularly preferably used as a protective tape for protecting a wafer, a semiconductor chip, or the like in the manufacture of parts.
As a method for manufacturing such an electronic component, for example, the following method for manufacturing an electronic component can be mentioned. That is, a substrate attaching step of attaching the adhesive tape of the present invention to a substrate from an ultraviolet curable adhesive layer, a curing step of irradiating ultraviolet rays to cure the ultraviolet curable adhesive layer, and the substrate being heated at 260 ° C. or higher. It is a method including a heat treatment step of treating at a high temperature and a peeling step of peeling the substrate from the adhesive tape of the present invention in this order.
Further, an adhesive tape having an adhesive layer on the surface opposite to the surface on which the ultraviolet curable adhesive layer of the base film is laminated, which is one embodiment of the present invention, is used as follows. There is also a method of manufacturing various electronic parts. That is, the substrate sticking step of sticking the adhesive tape from the ultraviolet curable pressure-sensitive adhesive layer to the substrate, the support sticking step of sticking the support on the pressure-sensitive adhesive layer, and the UV-curable pressure-sensitive adhesive by irradiating ultraviolet rays. It is a method including a curing step of curing the layer, a heat treatment step of treating the substrate at a high temperature of 260 ° C. or higher, and a peeling step of peeling the substrate from the adhesive tape in this order. Further, a substrate attaching step of attaching the adhesive tape to the substrate from the ultraviolet curable adhesive layer, a curing step of irradiating ultraviolet rays to cure the ultraviolet curable adhesive layer, and a support on the adhesive layer. It is a method including a support sticking step for sticking, a heat treatment step for treating the substrate at a high temperature of 260 ° C. or higher, and a peeling step for peeling the substrate from the adhesive tape in this order.

The substrate is not particularly limited, and examples thereof include silicon wafers, semiconductor wafers, and semiconductor chips.
The support is not particularly limited, and examples thereof include glass, a polyimide film, and a glass epoxy substrate.
The upper limit of the temperature of the heat treatment step for treating at a high temperature of 260 ° C. or higher is not particularly limited, and is, for example, 400 ° C., preferably 300 ° C.
The heat treatment step for treating at a high temperature of 260 ° C. or higher is not particularly limited, and examples thereof include a substrate manufacturing step, a chip mounting step, a thermocompression bonding bonding step, and a reflow step. More specifically, for example, a thermocompression bonding bonding step or a reflow step in which the adhesive tape is heated to 260 ° C. or higher for about several tens of seconds to one minute can be mentioned.

According to the present invention, it is possible to provide an adhesive tape that protects an adherend and can be peeled off without adhesive residue even when used in a step involving a high temperature treatment reaching 260 ° C.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example 1)
(Manufacturing of UV curable adhesive A)
A reactor equipped with a thermometer, a stirrer, and a cooling tube was prepared, and in this reactor, 94 parts by weight of 2-ethylhexyl acrylate as a (meth) acrylic acid alkyl ester and 6 parts by weight of hydroxyethyl methacrylate as a functional group-containing monomer were prepared. , 0.01 part by weight of lauryl mercaptan and 80 parts by weight of ethyl acetate were added, and then the reactor was heated to start reflux. Subsequently, 0.01 part by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane as a polymerization initiator was added into the reactor to initiate polymerization under reflux. rice field. Next, 0.01 parts by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added 1 hour and 2 hours after the start of the polymerization, and further, the polymerization was started. After 4 hours from the above, 0.05 part by weight of t-hexyl peroxypivalate was added to continue the polymerization reaction. Then, 8 hours after the start of the polymerization, an ethyl acetate solution of a functional group-containing (meth) acrylic polymer having a solid content of 55% by weight and a weight average molecular weight of 600,000 was obtained.
To 100 parts by weight of the resin solid content of the obtained ethyl acetate solution containing a functional group-containing (meth) acrylic polymer, 3.5 parts by weight of 2-isocyanatoethyl methacrylate was added as a functional group-containing unsaturated compound to react. A polymerizable polymer (acrylic polymer) A was obtained. Then, with respect to 100 parts by weight of the resin solid content of the obtained ethyl acetate solution of the acrylic polymer A, 20 parts by weight of the release agent (silicone), 3 parts by weight of the filler, 10 parts by weight of the urethane acrylate, and 0.2 parts by weight of the cross-linking agent. And 1 part by weight of the photopolymerization initiator were mixed to obtain an ethyl acetate solution of the ultraviolet curable pressure-sensitive adhesive A. The following mold release agents (silicone), fillers, urethane acrylates, cross-linking agents, and photopolymerization initiators were used.
Release agent (silicone): Silicone diacrylate, EBECRYL 350, manufactured by Dycel Ornex, weight average molecular weight 1000
Filler: Silica filler, Leoloseal MT-10, Urethane acrylate manufactured by Tokuyama Corporation: UN-5500, Cross-linking agent manufactured by Negami Kogyo Co., Ltd .: Isocyanate-based cross-linking agent, Coronate L, Photopolymerization initiator manufactured by Nippon Urethane Industry Co., Ltd. Made

(Manufacturing of Adhesive A for Adhesive Layer)
10 parts by weight of the release agent (silicone), 12 parts by weight of the filler, and 20 parts by weight of the urethane acrylate with respect to 100 parts by weight of the resin solid content of the ethyl acetate solution of the acrylic polymer A obtained in the production of the ultraviolet curable pressure-sensitive adhesive A. , 1.2 parts by weight of the cross-linking agent, 1 part by weight of the photopolymerization initiator, and 10 parts by weight of the gas generating agent were mixed to obtain an ethyl acetate solution of the pressure-sensitive adhesive A for the pressure-sensitive adhesive layer. The mold release agent (silicone), filler, urethane acrylate, cross-linking agent, and photopolymerization initiator used were the same as those used in the production of the ultraviolet curable pressure-sensitive adhesive. As the gas generator, a salt of a bistetrazole compound represented by the following formula (A) was used.

(Manufacturing of adhesive for anchor layer)
12 parts by weight of the filler and 5 parts by weight of the cross-linking agent were mixed with 100 parts by weight of the resin solid content of the ethyl acetate solution of the acrylic polymer to obtain an ethyl acetate solution of the pressure-sensitive adhesive for the anchor layer. The following acrylic polymers, fillers, and cross-linking agents were used.
Acrylic polymer: SK Dyne 1604N, Soken Chemical Co., Ltd. filler: Silica filler, Leoloseal MT-10, Tokuyama Corporation Cross-linking agent: Isocyanate-based cross-linking agent, Coronate L, Nippon Urethane Industry Co., Ltd.

(Manufacturing of adhesive tape)
The obtained ethyl acetate solution of the ultraviolet curable pressure-sensitive adhesive A is placed on the release-treated surface of a polyethylene terephthalate (PET) film having a thickness of 50 μm, and the thickness of the pressure-sensitive adhesive layer becomes 130 μm after drying. After coating as described above, it was dried at 100 ° C. for 10 minutes to form an ultraviolet curable pressure-sensitive adhesive layer.
On the other hand, on the release-treated surface of another PET film having a thickness of 50 μm, the obtained ethyl acetate solution of the pressure-sensitive adhesive A for the pressure-sensitive adhesive layer was dried, and the thickness of the pressure-sensitive adhesive layer was 20 μm. After coating so as to be, it was dried at 110 ° C. for 5 minutes to form an adhesive layer.
The ethyl acetate solution of the obtained adhesive for the anchor layer is placed on the release-treated surface of the PET film having another 50 μm-thickness release treatment so that the thickness of the pressure-sensitive adhesive layer becomes 10 μm after drying. After coating, it was dried at 110 ° C. for 5 minutes to form an anchor layer.
Next, a film (nylon 9T film) made of nylon 9T (Uniamide, manufactured by Unitika Ltd.) having a thickness of 25 μm and having corona treatment on both sides was prepared as a base film, and an anchor layer prepared on one side of the nylon 9T film was prepared. It was laminated and the PET film was peeled off to form an anchor layer on the base film. After that, the obtained ultraviolet curable adhesive layer was bonded onto the surface on which the anchor layer of the nylon 9T film was formed, and the adhesive obtained on the surface opposite to the surface on which the anchor layer of the nylon 9T film was formed. The layers were bonded together to obtain an adhesive tape having a structure of an ultraviolet curable adhesive layer / anchor layer / base film / adhesive layer.

(Measurement of UV transmittance of base film)
The transmittance of ultraviolet rays at 405 nm of the base film was measured using a spectrophotometer (U-3900, manufactured by Hitachi, Ltd.).

(Measurement of Ef (270))
A measurement sample was obtained by punching the base film to a size of 5 × 35 mm using a punching blade so that the long side was the same as the flow direction at the time of manufacturing the base film. The obtained measurement sample is immersed in liquid nitrogen and cooled to -50 ° C., and then, using a viscoelastic spectrometer (DVA-200, manufactured by IT Measurement Control Co., Ltd.), a constant-speed temperature rise tensile mode, temperature rise. The tensile elastic modulus was measured under the conditions of a speed of 10 ° C./min and a frequency of 10 Hz, and the tensile elastic modulus of the base film at 270 ° C. was measured.

(Measurement of storage elastic modulus G'before UV irradiation)
For the ultraviolet curable adhesive layer, a viscoelastic modulus (DVA-200, manufactured by IT Measurement Control Co., Ltd.) is used to store elastic modulus under the conditions of constant speed temperature rise shear mode, temperature rise rate 10 ° C./min, and frequency 10 Hz. Was measured, and the storage elastic modulus G'at 23 ° C. of the ultraviolet curable pressure-sensitive adhesive layer before irradiation with ultraviolet rays was determined.

(Measurement of gel fraction after UV irradiation)
Using a high-pressure mercury ultraviolet irradiation machine, the adhesive tape obtained with ultraviolet rays of 405 nm is irradiated from the base film side to the surface of the adhesive tape so that the integrated strength is 3000 mJ / cm ^2, and the ultraviolet curable adhesive layer is formed. Cross-linked and cured. Next, only 0.1 g of the cured UV-curable pressure-sensitive adhesive layer was scraped off, immersed in 50 ml of ethyl acetate, and shaken with a shaker at a temperature of 23 ° C. and 120 rpm for 24 hours (hereinafter, scraping). The UV-curable pressure-sensitive adhesive layer taken is called a pressure-sensitive adhesive composition). After shaking, a metal mesh (opening # 200 mesh) was used to absorb ethyl acetate and ethyl acetate, and the swollen pressure-sensitive adhesive composition was separated. The separated pressure-sensitive adhesive composition was dried under the condition of 110 ° C. for 1 hour. The weight of the pressure-sensitive adhesive composition containing the dried metal mesh was measured, and the gel fraction after ultraviolet irradiation was calculated using the following formula.
Gel fraction (%) = 100 × (W ₁ − W ₂ ) / W ₀
(W ₀ : Weight of initial pressure-sensitive adhesive composition, W ₁ : Weight of pressure-sensitive adhesive composition including dried metal mesh, W ₂ : Initial weight of metal mesh)

(Measurement of Et (270))
Using a high-pressure mercury ultraviolet irradiation machine, the adhesive tape obtained with ultraviolet rays of 405 nm is irradiated from the base film side to the surface of the adhesive tape so that the integrated strength is 3000 mJ / cm ^2, and the ultraviolet curable adhesive layer is formed. Cross-linked and cured. Next, a test piece having a size of 5 mm × 35 mm was produced by punching with a punching blade so that the long side was the same as the flow direction at the time of manufacturing the adhesive tape. The obtained test piece is immersed in liquid nitrogen and cooled to -50 ° C., and then, using a viscoelastic spectrometer (DVA-200, manufactured by IT Measurement Control Co., Ltd.), a constant-speed temperature rise tensile mode, temperature rise. The temperature was raised to 300 ° C. under the conditions of a speed of 10 ° C./min and a frequency of 10 Hz, and the tensile elastic modulus was measured. The value of the tensile elastic modulus (E') at the temperature X ° C. at this time was defined as Et (X). That is, the value of the tensile elastic modulus (E') at a temperature of 270 ° C. was set to Et (270).

(Calculation of Et (270) / Et (200))
With respect to the obtained adhesive tape, the tensile elastic modulus (Et (200)) of the adhesive tape at 200 ° C. was measured in the same manner as in Et (270). Et (270) / Et (200) was calculated from the obtained results of Et (270) and Et (200).

(Measurement of weight loss rate)
Using a high-pressure mercury ultraviolet irradiation machine, the adhesive tape obtained with ultraviolet rays of 405 nm is irradiated from the base film side to the surface of the adhesive tape so that the integrated strength is 3000 mJ / cm ^2, and the ultraviolet curable adhesive layer is formed. Cross-linked and cured. Next, the adhesive tape was punched into a circle having a diameter of 5 mm to obtain a measurement sample. The weight of the obtained measurement sample is measured, and the temperature is raised from 25 ° C to 280 ° C at a heating rate of 5 ° C / min using a differential thermal weight simultaneous measuring device (TG-DTA; STA7200, manufactured by Hitachi High-Tech Science Co., Ltd.). After that, the amount of weight loss when held for 10 minutes was measured. The weight loss rate was calculated from the weight before and after heating.

(Examples 2 to 10, Comparative Examples 1 to 4)
Adhesive tapes were obtained in the same manner as in Example 1 except that the material and thickness of the base film and the composition of the ultraviolet curable pressure-sensitive adhesive layer were changed as shown in Table 1, and each measurement was performed. Details of each material are shown below. In Example 5, the ultraviolet curable pressure-sensitive adhesive B shown below was used.
(1) Material of base film Expeak: Aromatic polyetheretherketone, Upirex manufactured by Clavow Co., Ltd .: Copolymer of biphenyltetracarboxylic acid dianhydride and p-phenylenediamine, Torsena manufactured by Ube Kosan Co., Ltd .: Special polyester, Clabow Capton manufactured by Toray DuPont, a copolymer of pyrrometic anhydride and diaminodiphenyl ether.

(2) UV curable adhesive B
(Manufacturing of UV curable adhesive B)
A reactor equipped with a thermometer, a stirrer, and a cooling tube was prepared, and in this reactor, 94 parts by weight of 2-ethylhexyl acrylate as a (meth) acrylic acid alkyl ester and 6 parts by weight of hydroxyethyl methacrylate as a functional group-containing monomer were prepared. , 0.01 part by weight of lauryl mercaptan and 80 parts by weight of ethyl acetate were added, and then the reactor was heated to start reflux. Subsequently, 0.01 part by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane as a polymerization initiator was added into the reactor to initiate polymerization under reflux. rice field. Next, 0.01 parts by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added 1 hour and 2 hours after the start of the polymerization, and further, the polymerization was started. After 4 hours from the above, 0.05 part by weight of t-hexyl peroxypivalate was added to continue the polymerization reaction. Then, 8 hours after the start of the polymerization, an ethyl acetate solution of a functional group-containing (meth) acrylic polymer having a solid content of 55% by weight and a weight average molecular weight of 600,000 was obtained.
To 100 parts by weight of the resin solid content of the obtained ethyl acetate solution containing a functional group-containing (meth) acrylic polymer, 1.0 part by weight of 2-isocyanatoethyl methacrylate was added as a functional group-containing unsaturated compound to react. The mixture was allowed to obtain a polymerizable polymer (acrylic polymer) B. Then, with respect to 100 parts by weight of the resin solid content of the obtained ethyl acetate solution of the acrylic polymer B, 20 parts by weight of the release agent (silicone), 3 parts by weight of the filler, 10 parts by weight of the urethane acrylate, and 0.2 parts by weight of the cross-linking agent. And 1 part by weight of the photopolymerization initiator were mixed to obtain an ethyl acetate solution of the ultraviolet curable pressure-sensitive adhesive B. The mold release agent (silicone), filler, urethane acrylate, cross-linking agent, and photopolymerization initiator used were of the same type as the ultraviolet curable pressure-sensitive adhesive A.

(3) Other photosensitizers: KAYACURE DETX-S, manufactured by Nippon Kayaku Co., Ltd.

<Evaluation>
The adhesive tapes obtained in Examples and Comparative Examples were evaluated by the following methods. The results are shown in Table 1.

(Evaluation of heat resistance)
The ultraviolet curable adhesive layer side of the adhesive tape cut into a circle having a diameter of 20 cm was attached to a silicon wafer having a diameter of 20 cm and a thickness of about 750 μm. Next, the adhesive layer side of the adhesive tape was attached to a glass wafer (Tempax, manufactured by SCHOTT) having a diameter of 20 cm and a thickness of 0.6 mm. After sticking, with the wavelength of 365 nm or less cut by a filter, ultraviolet light with a wavelength of 405 nm is irradiated from the glass wafer surface side to the ultraviolet curable adhesive layer so that the integrated intensity becomes 3000 mJ / cm ^2. The curable pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer were crosslinked and cured. The obtained silicon wafer / adhesive tape / glass wafer laminate is placed on a hot plate (NINOS ND-3H, manufactured by AS ONE) set at 280 ° C. with the silicon wafer side down, and the adhesive tape is peeled off. The time until it occurred was measured.

(Evaluation of peelability)
The UV-curable adhesive layer side of the adhesive tape is bonded to a silicon wafer having a diameter of 20 cm and a thickness of about 750 μm, and the adhesive layer side is further bonded to a glass wafer having a diameter of 20 cm and a thickness of 0.6 mm to form a laminate. Got Next, using a high-pressure mercury ultraviolet ray irradiator, the illuminance is adjusted so that the irradiation intensity of the adhesive tape on the surface of the adhesive tape is 100 mW / cm ² with ultraviolet rays of 405 nm, and the ultraviolet rays are irradiated from the glass wafer side for 30 seconds. The curable pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer were crosslinked and cured. Then, the laminate was placed on a hot plate set at 280 ° C. with the silicon wafer side down, heat-treated for 10 minutes, and allowed to cool.
After allowing to cool, the adhesive tape was peeled off from the silicon wafer. The peelability was evaluated as "○" when the adhesive tape could be easily peeled off and "x" when the adhesive tape could not be peeled off. When the adhesive tape was peeled off within 10 minutes, the heat treatment was stopped at the peeled stage, and the peelability after allowing to cool was evaluated.

(Evaluation of adhesive residue)
In the evaluation of the peelability, the silicon wafer after the adhesive tape was peeled off was observed with an optical microscope, and the case where the area where the adhesive remained was less than 5% of the entire silicon wafer was "◎", and it was 5% or more and less than 20%. The case was evaluated as "◯", the case of 20% or more and less than 50% was evaluated as "Δ", and the case of 50% or more was evaluated as "x".

(Evaluation of peelability during thermocompression bonding)
On the UV curable adhesive layer side of the adhesive tape cut into a circle with a diameter of 20 cm, bumps of a silicon wafer with bumps (bump diameter φ = 20 μm, bump distance 30 μm, bump height 45 μm) with a diameter of 20 cm and a thickness of 50 μm are formed. It was attached to the formed surface. Next, the adhesive layer side of the adhesive tape was attached to a glass wafer (Tempax, manufactured by SCHOTT) having a diameter of 20 cm and a thickness of 0.6 mm. After sticking, with the wavelength of 365 nm or less cut by a filter, ultraviolet light with a wavelength of 405 nm is irradiated from the glass wafer surface side to the ultraviolet curable adhesive layer so that the integrated intensity becomes 3000 mJ / cm ^2. The curable pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer were crosslinked and cured. The obtained silicon wafer / adhesive tape / glass wafer laminate was allowed to stand for 1 hour in an oven set at 200 ° C. with the glass wafer side facing down, and heat-treated.
A single crystal silicon thin wafer chip having a thickness of 50 μm was laminated on a laminated silicon wafer that had returned to room temperature after heat treatment using a flip chip bonder (FC6000, manufactured by Shibaura Mechatronics Co., Ltd.). Specifically, the laminate is adsorbed on the SUS stage set at 80 ° C. so that the silicon wafer surface faces up, and the single crystal silicon thin wafer chip (9.8 mm × 9.8 mm, thickness 50 μm, Wafers (with a bonding film having a surface roughness of less than 0.1 μm and a thickness of 25 μm) were laminated using a ceramic tool having a head size of 10 mm × 10 mm. The temperature of the head at the time of laminating was 280 ° C., the pressure was 300 N, and the laminating time was 90 seconds.
After laminating the single crystal silicon thin wafer chips, the adhesive tape was peeled off from the silicon wafer. The peelability at the time of thermocompression bonding was evaluated as "○" when the adhesive tape could be easily peeled off at the time of peeling and "x" when the adhesive tape could not be peeled off.

(Evaluation of adhesive residue during thermocompression bonding)
In the evaluation of the peelability during thermocompression bonding, the silicon wafer after peeling the adhesive tape was observed with an optical microscope. Of the bumps existing in the range of 500 μm square, “◎” is when the number of bumps remaining on the glue is 5% or less, “○” is when it is more than 5% and 20% or less, and more than 20% is 50. When it was less than%, it was evaluated as "Δ", and when it was more than 50%, it was evaluated as "x", and the adhesive residue during thermocompression bonding was evaluated.

According to the present invention, it is possible to provide an adhesive tape that protects an adherend and can be peeled off without adhesive residue even when used in a step involving a high temperature treatment reaching 260 ° C.

Claims (10)

An adhesive tape having a base film and an ultraviolet curable pressure-sensitive adhesive layer laminated on one side of the base film.
The gel fraction of the ultraviolet curable adhesive layer after irradiating the surface of the adhesive tape on the base film side with ultraviolet rays of 405 nm at 3000 mJ / cm ^{2 is 90% or more.}
When the tensile elastic modulus at X ° C. of the adhesive tape after irradiating the surface of the adhesive tape on the base film side with the ultraviolet rays of 405 nm at 3000 mJ / cm ² is Et (X), the value of Et (270) is Adhesive tape with 1.0 x 10 ⁷ Pa or more. The adhesive tape according to claim 1, wherein the base film has an ultraviolet transmittance of 1% or more at 405 nm. The adhesive tape according to claim 1 or 2, wherein the value of Et (270) / Et (200) is 0.1 or more. When the tensile modulus at X ° C. of the base film and Ef (X), the value of Ef (270) is that 5.0 × ¹⁰ 7 Pa or higher, according to claim 1, 2 or 3 pressure-sensitive adhesive tape according. When the surface of the adhesive tape on the base film side is ^{irradiated with the ultraviolet rays of 405 nm at 3000 mJ / cm 2} , the temperature is raised from 25 ° C. to 280 ° C. at a rate of 5 ° C./min, and the temperature is held for 10 minutes. The adhesive tape according to claim 1, 2, 3 or 4, wherein the weight loss rate of the adhesive tape is 5% or less. The base film according to claim 1, 2, 3, 4 or 5, wherein the base film contains a resin having at least one selected from the group consisting of amides, imides, ethers and ketones in the main chain skeleton of a repeating unit. Adhesive tape. The base film contains a polyamide resin having a long-chain alkyl group having 4 or more and 12 or less carbon atoms or an aromatic in the main chain skeleton of a repeating unit, according to claim 1, 2, 3, 4, 5 or 6. Adhesive tape described The ultraviolet curable pressure-sensitive adhesive layer contains a (meth) acrylic acid alkyl ester-based polymerizable polymer having a radically polymerizable unsaturated bond in the molecule, a polymerization initiator, and a functional group that can be crosslinked with the polymerizable polymer. The adhesive tape according to claim 1, 2, 3, 4, 5, 6 or 7, which has a silicone or a fluoropolymer having the same. The invention according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein the base film has an adhesive layer on a surface opposite to the surface on which the ultraviolet curable adhesive layer is laminated. Adhesive tape. The adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, which is used for manufacturing an electronic component.