KR20150127087A - Adhesive sheet - Google Patents

Abstract

Provided is a pressure-sensitive adhesive sheet capable of realizing excellent cutting precision and cutting chips when cutting small parts such as electronic parts. The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive surface whose adhesive strength is lowered by heating only on one side, and the elastic modulus of the surface opposite to the pressure-sensitive adhesive surface by the nanoindentation method is 1 MPa or more. In a preferred embodiment of the present invention, it is preferable that one surface of the pressure-sensitive adhesive layer has a pressure-sensitive adhesive region where one surface is the pressure-sensitive adhesive surface and a covering material region adjacent to the pressure- ≪ / RTI >

Description

ADHESIVE SHEET [0002]

The present invention relates to a pressure-sensitive adhesive sheet.

In the production of electronic components such as silicon wafers, multilayer capacitors, transparent electrodes, etc., a substrate obtained by making necessary functions collectively in a large area is smoothened to a desired size by cutting. A pressure-sensitive adhesive sheet for fixing a work (substrate) is used for preventing cutting accuracy from being lowered due to stress and vibration at the time of cutting. The pressure-sensitive adhesive sheet is required to have sufficient adhesive strength to the workpiece at the time of processing, and to be able to easily peel off the processed workpiece (electronic component) after processing. As such a pressure-sensitive adhesive sheet, a pressure-sensitive adhesive sheet containing heat-expandable microspheres in a pressure-sensitive adhesive is known (see, for example, Patent Document 1). The pressure-sensitive adhesive sheet containing the thermally expandable microspheres exhibits a sufficient adhesive force at the time of processing because the adhesive force of the heat-expandable microspheres is lowered by expanding or foaming the heat-expandable microspheres by heating. It can peel off.

BACKGROUND ART In recent years, light weight and miniaturization of electronic parts have progressed, and a pressure-sensitive adhesive sheet for fixing workpieces capable of realizing cutting with higher accuracy has been demanded. In addition, reduction of the processing debris (cutting chips) generated at the time of cutting is also required. It is considered that a pressure-sensitive adhesive sheet capable of achieving higher cutting accuracy and cutting chips can be obtained by thinning the pressure-sensitive adhesive constituting the pressure-sensitive adhesive sheet against such a demand. However, the pressure-sensitive adhesive sheet including the thermally expandable microspheres has the problem that the thickness of the pressure-sensitive adhesive is limited because it includes thermally expandable microspheres. More specifically, in the case of a pressure-sensitive adhesive sheet including thermally expandable microspheres, if the pressure-sensitive adhesive is made thinner, the thermally expandable microspheres protrude from the pressure-sensitive adhesive, and the adhesiveness with the substrate or the processing table is deteriorated, have.

Japanese Patent Application Laid-Open No. 2002-121510

An object of the present invention is to provide a pressure-sensitive adhesive sheet capable of realizing excellent cutting precision and cutting chips at the time of cutting small parts such as electronic parts have.

The pressure-sensitive adhesive sheet of the present invention has only one pressure-sensitive adhesive surface whose adhesive force is lowered by heating, and the elastic modulus of the surface opposite to the pressure-sensitive adhesive surface at 25 캜 according to the nanoindentation method is 1 MPa or more.

In a preferred embodiment, it is preferable that the pressure-sensitive adhesive layer has a pressure-sensitive adhesive area including the pressure-sensitive adhesive surface as a surface and a covering area adjacent to the pressure-sensitive adhesive surface on the opposite side of the pressure- Includes microspheres.

In a preferred embodiment, the thickness of the pressure sensitive adhesive region is 50 占 퐉 or less.

In a preferred embodiment, the adhesive strength when the adhesive surface side is adhered to the polyethylene terephthalate film is 0.2 N / 20 mm or more.

In a preferred embodiment, the pressure-sensitive adhesive sheet of the present invention has a ratio (a2 / a1) of the adhesive force a1 before heating to the adhesive force a2 after heating of from 0.0001 to 0.5.

In a preferred embodiment, the surface roughness (Ra) of the adhesive surface after heating is 3 占 퐉 or more.

In a preferred embodiment, a substrate is further provided on the opposite side of the adhesion surface.

According to another aspect of the present invention, a method of manufacturing an electronic component is provided. This manufacturing method includes a step of bonding an electronic component material on the adhesive sheet and then cutting the electronic component material.

According to the present invention, it is possible to realize excellent cutting precision at the time of cutting a small component such as an electronic part by having a pressure-sensitive adhesive surface whose adhesive force is lowered by heating and having a relatively high modulus of elasticity on the surface opposite to the pressure- A pressure-sensitive adhesive sheet can be obtained. More specifically, in the present invention, a pressure-sensitive adhesive region having a pressure-sensitive adhesive surface as a surface including a pressure-sensitive adhesive and a thermally expanding microsphere is formed, and a relatively high-elastic covering material region is formed on the side opposite to the pressure- It is possible to thin the pressure sensitive adhesive region in the low elastic region without the influence of the unevenness by the thermally expandable microspheres protruding from the pressure sensitive adhesive region by embedding the thermally expandable microspheres protruding from the pressure sensitive adhesive region into the covering material region, A pressure-sensitive adhesive sheet capable of realizing precision can be obtained. Further, according to the present invention, since the pressure sensitive adhesive region can be made thinner, the occurrence of cutting chips can be suppressed by cutting a small component such as an electronic component using the pressure sensitive adhesive sheet of the present invention.

1 is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to a preferred embodiment of the present invention.
2 is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to another preferred embodiment of the present invention.
Fig. 3 is a diagram showing Raman mapping obtained by measuring the thickness in the third embodiment. Fig.
4 is a cross-sectional SEM image of the pressure-sensitive adhesive sheet in Example 11. Fig.

A. Overall construction of adhesive sheet

1 is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to a preferred embodiment of the present invention. The adhesive sheet (100) has an adhesive surface (11) only on one side thereof. The adhesive sheet 100 has a surface 21 on the opposite side of the adhesive surface 11 and a surface 21 having an elastic modulus of 1 MPa or more by the nanoindentation method at 25 캜. The surface having such a modulus of elasticity can be formed, for example, by providing the covering material region 20 as follows. The adhesive sheet 100 preferably includes a thermally expandable microspheres 13 that can expand or foam by heating.

The adhesive sheet 100 has a pressure sensitive adhesive region 10 including a pressure sensitive adhesive surface 11 as a surface and a covering region 20 adjacent to the pressure sensitive adhesive surface 11 on the opposite side of the pressure sensitive adhesive region 10. The pressure sensitive adhesive region 10 preferably comprises a pressure sensitive adhesive 12 and a thermally expandable microsphere 13. The pressure sensitive adhesive region 10 refers to the area from the pressure sensitive adhesive surface 11 to the interface 1 of the material constituting the pressure sensitive adhesive 12 and the covering material region 20 constituting the pressure sensitive adhesive region 10. The covering material region 20 is a region in which the pressure sensitive adhesive 12 constituting the pressure sensitive adhesive region 10 and the surface 1 of the material constituting the covering material region 20 extend from the surface 21 opposite to the pressure sensitive adhesive surface 11 ). The thermally expandable microspheres 13 may protrude from the pressure-sensitive adhesive region 10 to the covering material region 20. The thermally expandable microspheres 13 protruding from the pressure-sensitive adhesive region 10 can be covered by the covering material region 20, and as a result, the influence of the unevenness by the thermally expandable microspheres 13 can be eliminated. The outer surface (lower surface in the illustrated example) of the covering material region 20 becomes a surface 21 having an elastic modulus of 1 MPa or more by the nanoindentation method. Although not shown, a peeling paper may be disposed outside the adhesive surface 11 to protect the adhesive surface 11 until the adhesive sheet is provided for practical use. In the illustrated example, the interface 1 is clearly shown, but the interface may be an interface that is difficult to distinguish by visual observation, microscope, or the like. The interface that is difficult to distinguish by visual observation, microscope, etc. can be discriminated by analyzing the composition of each region (details will be described later).

In the present invention, since the cover material region 20 having a moderate modulus of elasticity is formed on the opposite side of the pressure-sensitive adhesive surface 11, the thermally expandable microspheres 13 are allowed to protrude from the pressure-sensitive adhesive region 10 , So that the pressure sensitive adhesive region 10 can be made thin. If the pressure sensitive adhesive region 10, which is a low elasticity region, is thinned, it can contribute to realization of excellent cutting precision as a temporary fixing sheet for cutting an electronic component or the like. More specifically, when an electronic component or the like is cut using a thin adhesive sheet as a temporary fixing sheet, since the deformation of the adhesive sheet is small, the chips after the cutting are reattached, It is possible to prevent the chip from becoming unstable due to being oblique or S-shaped, chip cutting during cutting, and the like. Further, when a thin pressure sensitive adhesive sheet 10 is used as a temporary fixing sheet at the time of cutting an electronic component or the like, generation of cutting chips can be suppressed. INDUSTRIAL APPLICABILITY The pressure-sensitive adhesive sheet of the present invention not only exhibits the above-mentioned effect in cutting by rotary blades mostly used in the dicing step but also exerts the above effect even in cutting by flat pressing employed for reducing cutting loss , Which is particularly useful. Further, even in the case of cutting at a temperature (for example, 30 ° C to 150 ° C), cutting can be performed with high precision as described above.

In the pressure-sensitive adhesive sheet of the present invention, since the thermally expandable microspheres 13 are present on the pressure-sensitive adhesive surface 11 side (pressure-sensitive adhesive region 10), the adherend (for example, When peeling from the sheet, irregularities are generated on the adhesive surface by heating the thermally expandable microspheres 13 to a temperature at which the expandable microspheres 13 can expand or foam, thereby reducing or eliminating the adhesive force of the adhesive surface.

The adhesive strength when the adhesive surface of the pressure-sensitive adhesive sheet of the present invention is adhered to a polyethylene terephthalate film (for example, a thickness of 25 mu m) is preferably 0.2 N / 20 mm or more, more preferably 0.2 N / 20 mm to 20 N / 20 mm, and more preferably 2 N / 20 mm to 10 N / 20 mm. In such a range, a pressure-sensitive adhesive sheet useful as a temporary fixing sheet for cutting an electronic component or the like can be obtained. In this specification, the adhesive force refers to the adhesive force measured by the method according to JIS Z 0237: 2000 (measuring temperature: 23 ° C, bonding condition: 2 kg roller 1 round trip, peeling speed: 300 mm / min, peeling angle: 180 °).

The adhesive strength of the pressure-sensitive adhesive sheet of the present invention after being adhered to a polyethylene terephthalate film (for example, a thickness of 25 mu m) and heated is preferably 0.2 N / 20 mm or less, more preferably 0.1 N / Or less. In the present specification, the heating on the pressure-sensitive adhesive sheet refers to the heating at a temperature and a time at which the thermo-expandable microspheres expand or foam to lower the adhesive force. The heating is, for example, heating at 70 캜 to 270 캜 for 1 minute to 10 minutes.

The ratio of the adhesive force (that is, the adhesive force a1 before heating) and the adhesive force a2 (when the adhesive surface of the adhesive sheet of the present invention is adhered to a polyethylene terephthalate film (for example, a2 / a1) is preferably 0.5 or less, and more preferably 0.1 or less. The lower limit of (a2 / a1) is preferably 0.0001, more preferably 0.0005.

As described above, in the pressure-sensitive adhesive sheet of the present invention, irregularities are generated on the pressure-sensitive adhesive surface by heating to a predetermined temperature. The surface roughness (Ra) of the adhesive surface after heating the pressure-sensitive adhesive sheet of the present invention is preferably 3 m or more, and more preferably 5 m or more. In such a range, a pressure-sensitive adhesive sheet capable of easily peeling an adherend can be obtained because the adhesive strength is lowered or lost after heating. The surface roughness (Ra) of the adhesive surface refers to the surface roughness (Ra) of the adhesive surface of the adhesive sheet after heating in the absence of the adherend. The surface roughness (Ra) can be measured according to JIS B 0601: 1994.

2 is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to another preferred embodiment of the present invention. The adhesive sheet (200) further comprises a base material (30) on the side opposite to the adhesive surface (11). Although not shown, any appropriate pressure-sensitive adhesive layer or adhesive layer may be provided on the opposite side of the covering material region 20 of the base material 30. [ In addition, the adhesive sheet of the present invention may be provided with a release paper on the outside of the base material 30 until it is provided for practical use. When a release paper is disposed outside the base material 30, the release paper can be adhered to the base material through any suitable pressure-sensitive adhesive. 2 shows a mode in which the pressure sensitive adhesive region 10 and the covering material region 20 are formed on one side of the base material 30 but the pressure sensitive adhesive region 10 and the covering material region 20 For example, in the form of a pressure sensitive adhesive region / covering material region / substrate / covering material region / pressure sensitive adhesive region.

B. Covering area

In the pressure-sensitive adhesive sheet of the present invention, the elastic modulus of the surface opposite to the pressure-sensitive adhesive surface by the nanoindentation method at 25 DEG C is 1 MPa or more, preferably 1 MPa to 5000 MPa, more preferably 1 MPa To 3500 MPa, more preferably from 1 MPa to 1000 MPa, and particularly preferably from 10 MPa to 600 MPa. The pressure-sensitive adhesive sheet having such a surface showing the elastic modulus can be obtained, for example, by forming a covering material region formed of a material different from that of the pressure-sensitive adhesive region. The elastic modulus by the nanoindentation method of the covering material region may be equivalent to the elastic modulus by the nanoindentation method of the surface opposite to the adhesive surface. The elastic modulus according to the nanoindentation method is a method in which the load applied to the indenter and the indentation depth when the indenter is press-fitted into the sample (for example, the adhesive surface) are continuously measured during unloading when the indentation is loaded, Load - refers to the modulus of elasticity determined from the indentation depth curve. In the present specification, the elastic modulus according to the nanoindentation method refers to the elastic modulus measured as described above under the conditions of a load of 1 mN, a loading / unloading speed of 0.1 mN / s, and a holding time of 1 s.

In the present invention, it is preferable that a surface having a modulus of elasticity of 1 MPa or more by the nanoindentation method is formed on the side opposite to the pressure-sensitive adhesive surface, that is, by forming a covering material region exhibiting the modulus of elasticity, It is possible to provide a pressure-sensitive adhesive sheet which can contribute to realization of excellent cutting precision as a fixing sheet. By setting the modulus of elasticity of the covering material region by the nanoindentation method to 5,000 MPa or less, the covering material region can follow the unevenness of the thermally expandable microspheres protruding from the pressure-sensitive adhesive region, and the thermally expandable microspheres , The thermally expansible microspheres can be coated. In addition, it is possible to provide a pressure-sensitive adhesive sheet capable of contributing to realization of excellent cutting precision without damaging the flexibility required for the whole pressure-sensitive adhesive sheet (for example, flexibility that can follow the adherend).

The tensile modulus of the covering material region at 25 캜 is preferably 1 MPa or more, more preferably 1 MPa to 5,000 MPa, and still more preferably 1 MPa to 1000 MPa. With such a range, the same effects as those described above can be obtained with respect to the elastic modulus by the nanoindentation method. The tensile modulus can be measured in accordance with JIS K 7161: 2008.

The bending elastic modulus of the covering material region at 25 캜 is preferably 1 MPa or more, more preferably 1 MPa to 5,000 MPa, and still more preferably 1 MPa to 1000 MPa. With such a range, the same effects as those described above can be obtained with respect to the elastic modulus by the nanoindentation method. The bending elastic modulus can be measured in accordance with JIS K 7171: 2008.

The thickness of the covering material region may be set to any appropriate value depending on the amount (size) of the thermally expansible microspheres protruding from the pressure-sensitive adhesive region. The thickness of the covering material region is preferably such that it can cover all of the thermally expansible microspheres protruding from the pressure-sensitive adhesive region, and is, for example, 0.1 to 200 탆, preferably 0.1 to 100 탆, Is in the range of 0.1 탆 to 45 탆. 1, the thickness of the covering material region means the thickness of the coating material constituting the covering material region 20 and the thickness of the boundary between the coating material constituting the covering material region 20 and the interface 1 of the pressure sensitive adhesive 12 constituting the pressure sensitive adhesive region 10 And the surface 21 on the opposite side of the interface 1 of the covering material region. That is, the portion where the thermally expandable microspheres 13 protrude from the pressure-sensitive adhesive region 10 is not to be evaluated for the thickness of the covering material region. When the adhesive sheet is cut and the end face is visually observed, when the interface 1 is clear, the thickness of the covering material region can be measured using a normal, vernier caliper, or micrometer. In addition, the thickness of the covering material region may be measured using a microscope such as an electron microscope, an optical microscope, or an atomic force microscope. Further, the thickness of the covering material region may be measured by discriminating the interface depending on the composition of the covering material region and the pressure sensitive adhesive region. For example, spectral analysis such as Raman spectroscopy, infrared spectroscopy, and X-ray electron spectroscopy; The composition of the coating material constituting the coating material area and the composition of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive area are determined by mass analysis such as matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS) or flight time secondary ion mass spectrometry (TOF- SIMS) And the thickness of the covering material region can be measured by determining the interface according to the difference of the composition. Thus, the method of discriminating the interface by spectroscopic analysis or mass spectrometry is useful when it is difficult to discriminate the interface by visual observation or observation using a microscope.

Examples of the material constituting the covering material region include a silicone polymer, an epoxy polymer, a polycarbonate polymer, a vinyl polymer, an acrylic polymer, a urethane polymer, a polyester polymer (for example, polyethylene terephthalate) Based polymer, a polyolefin-based polymer, a polyamide-based polymer, a polyimide-based polymer, and an unsaturated hydrocarbon-based polymer. When these polymer materials are used, a covering material region having the above-mentioned elastic modulus can be easily formed by appropriately selecting monomer species, crosslinking agent, degree of polymerization and the like. In addition, the polymer material is excellent in the affinity with the heat-expandable microspheres, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive region and the substrate. These polymer materials may be used singly or in combination of two or more.

As the material constituting the covering material region, a resin material which can be hardened (high elastic modulus) by irradiation of an active energy ray may be used. When the covering material region is formed by such a material, a pressure-sensitive adhesive sheet which can be adjusted to have the above-mentioned range of elasticity can be obtained by irradiating an active energy ray with excellent flexibility, Can be obtained. Examples of the active energy ray include gamma ray, ultraviolet ray, visible ray, infrared ray (heat ray), radio wave, alpha ray, beta ray, electron ray, plasma ray, ion beam and particle ray. The coverage of the coating material composed of a resin material that can be cured by irradiation of an active energy ray has an elastic modulus in the above range after the irradiation of the active energy ray by the nanoindentation method. It is preferable that the tensile modulus of elasticity and / or the flexural modulus of elasticity of the covering material region composed of a resin material that can be cured by irradiation with an active energy ray are within the above range after irradiation with an active energy ray.

Examples of the resin material that can be cured (high elastic modulus) by the irradiation of an active energy ray include an ultraviolet curing system (published by Kato Kiyomi, Integrated Technology Center (1989)), a light curing technique ), Japanese Patent Application Laid-Open Nos. 2003-292916 and 4151850, and the like. More specifically, there can be mentioned a resin material (R1) containing a polymer to be aggregated and an active energy ray-reactive compound (monomer or oligomer), and a resin material (R2) containing an active energy ray-reactive polymer.

Examples of the polymer that can be used as the polymer include natural rubber, polyisobutylene rubber, styrene / butadiene rubber, styrene / isoprene / styrene block copolymer rubber, regenerated rubber, butyl rubber, polyisobutylene rubber, nitrile rubber ); Silicone-based polymers; Acrylic polymers and the like. These polymers may be used singly or in combination of two or more kinds.

Examples of the active energy ray-reactive compound include photoreactive monomers or oligomers having a functional group having a carbon-carbon multiple bond such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group, and an acetylene group . Specific examples of the photoreactive monomer or oligomer include trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra Acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexane diol di (meth) acrylate, dipentaerythritol monohydroxypenta (Meth) acryloyl group-containing compounds such as polyethylene glycol di (meth) acrylate; 2- to 5-mer of the corresponding (meth) acryloyl group-containing compound, and the like.

Examples of the active energy ray-reactive compound include monomers such as epoxidized butadiene, glycidyl methacrylate, acrylamide, and vinyl siloxane; Or an oligomer composed of the corresponding monomer may be used. The resin material (R1) containing these compounds can be cured by high energy rays such as ultraviolet rays and electron beams.

As the active energy ray-reactive compound, a mixture of an organic salt such as an onium salt and a compound having a plurality of heterocyclic rings in a molecule may be used. The mixture is formed by opening the organic salt by irradiation of an active energy ray (for example, ultraviolet rays, electron rays) to generate ions, which is converted into an open species to cause a ring opening reaction of a heterocyclic ring to form a three- have. Examples of the organic salts include iodonium salts, phosphonium salts, antimonium salts, sulfonium salts, borate salts and the like. Examples of the heterocycle in the compound having a plurality of heterocyclic rings in the molecule include oxirane, oxetane, oxolane, thiirane, and aziridine.

In the resin material (R1) comprising the polymer to be aggregated and the active energy ray-reactive compound, the content of the active energy ray-reactive compound is preferably from 0.1 to 500 parts by weight per 100 parts by weight of the polymer More preferably 1 part by weight to 300 parts by weight, and still more preferably 10 parts by weight to 200 parts by weight.

The resin material (R1) containing the above-mentioned polymer to be aggregated and the active energy ray-reactive compound may optionally contain any suitable additives. As the additive, for example, an active energy ray polymerization initiator, an active energy ray polymerization accelerator, a crosslinking agent, a plasticizer, a vulcanizing agent and the like can be given. As the active energy ray polymerization initiator, any suitable initiator may be used depending on the kind of active energy ray to be used. The active energy ray polymerization initiators may be used singly or in combination of two or more kinds. In the resin material (R1) containing the polymer to be aggregated and the active energy ray-reactive compound, the content of the active energy ray polymerization initiator is preferably 0.1 part by weight to 10 parts by weight More preferably 1 part by weight to 5 parts by weight.

Examples of the active energy ray-reactive polymer include a polymer having a functional group having a carbon-carbon multiple bond such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group, and an acetylene group. Specific examples of the polymer having an active energy ray-reactive functional group include a polymer composed of a polyfunctional (meth) acrylate; A photo cationic polymerizable polymer; A neomoyl group-containing polymer such as polyvinyl cinnamate; Diazotized aminovorak resins; Polyacrylamide, and the like. As the resin material (R2) containing the active energy ray-reactive polymer, a mixture of a compound having an active energy ray-reactive polymer having an allyl group and a compound having a thiol group may also be used. As long as a coating material region precursor having practically acceptable hardness (viscosity) can be formed before curing by irradiation with active energy rays (for example, when adhering an adhesive sheet), a polymer having an active energy ray- An oligomer having an active energy ray-reactive functional group may be used.

The resin material (R2) comprising the active energy ray-reactive polymer may further contain the active energy ray-reactive compound (monomer or oligomer). Further, the resin material (R2) containing the active energy ray-reactive polymer may contain any suitable additives, if necessary. Specific examples of the additive are the same as those that can be contained in the resin material (R1) containing the polymer to be aggregated and the active energy ray-reactive compound. In the resin material (R2) containing the active energy ray-reactive polymer, the content of the active energy ray polymerization initiator is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the active energy ray- Preferably 1 part by weight to 5 parts by weight.

The covering material region may further include beads. Examples of the beads include glass beads and resin beads. By adding such beads to the covering material region, the elasticity of the covering material region can be improved, and a pressure-sensitive adhesive sheet capable of processing a workpiece with higher precision can be obtained. The average particle diameter of the beads is, for example, 0.01 탆 to 50 탆. The amount of the beads to be added is, for example, 10 parts by weight to 200 parts by weight, preferably 20 parts by weight to 100 parts by weight, relative to 100 parts by weight of the entire covering material region.

C. Adhesive Area

The pressure sensitive adhesive region preferably includes a pressure sensitive adhesive and a thermally expansive microsphere.

The thickness of the pressure sensitive adhesive region is preferably 50 占 퐉 or less, more preferably 1 占 퐉 to 50 占 퐉, still more preferably 1 占 퐉 to 25 占 퐉, and particularly preferably 1 占 퐉 to 15 占 퐉. When the thickness of the pressure sensitive adhesive region is thicker than 50 占 퐉, when the electronic component or the like is used as a temporary fixing sheet for cutting, the chips after the cutting are reattached, the cut surface becomes unstable, There is a possibility that a problem such as generation of cutting chips may occur. In the present invention, since the covering material region in which the modulus of elasticity is appropriately adjusted is formed, the thermally expandable microspheres can protrude from the pressure-sensitive adhesive region, and the pressure-sensitive adhesive region can be thinned. On the other hand, when the thickness of the pressure sensitive adhesive region is less than 1 占 퐉, sufficient adhesive force may not be obtained. In the present specification, the thickness of the pressure-sensitive adhesive region means the thickness of the pressure-sensitive adhesive layer from the interface 1 of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive region 10 to the covering material constituting the covering material region 20, (11). That is, the portion where the thermally expandable microspheres 13 protrude from the pressure-sensitive adhesive region 10 is not to be evaluated for the thickness of the pressure-sensitive adhesive region. The method of discriminating the interface 1 is the same as described in the section B above.

The pressure-sensitive adhesive sheet of the present invention preferably has a modulus of elasticity by the nanoindentation method of the pressure-sensitive adhesive surface at a temperature at which the pressure-sensitive adhesive sheet is adhered is preferably less than 100 MPa, more preferably from 0.1 MPa to 50 MPa, More preferably 0.1 MPa to 10 MPa. The elastic modulus by the nanoindentation method of the pressure sensitive adhesive area corresponds to the elastic modulus by the nanoindentation method of the pressure sensitive adhesive surface. The elastic modulus of the adhesive surface by the nanoindentation method refers to the elastic modulus measured by the measuring method described in the above section B, i.e., the elastic modulus of the pressure-sensitive adhesive, by selecting a portion having no thermally expandable microspheres. The temperature at which the pressure-sensitive adhesive sheet is adhered is, for example, from 10 캜 to 80 캜 when an acrylic pressure-sensitive adhesive is used as the pressure-sensitive adhesive, and from 40 캜 to 120 캜 when a styrene-diene block copolymer pressure-

(adhesive)

It is preferable that the pressure-sensitive adhesive does not constrain expansion or foaming of the thermally expandable microspheres upon heating. Examples of the pressure sensitive adhesive include acrylic pressure sensitive adhesives, rubber pressure sensitive adhesives, vinyl alkyl ether pressure sensitive adhesives, silicone pressure sensitive adhesives, polyester pressure sensitive adhesives, polyamide pressure sensitive adhesives, urethane pressure sensitive adhesives, styrene - diene block copolymer pressure sensitive adhesives, radiation curable pressure sensitive adhesives, And a creep property improving type pressure-sensitive adhesive containing a heat-fusible resin having a temperature of about 200 ° C or lower (see, for example, Japanese Patent Application Laid-open No. 56-61468 and Japanese Patent Application Laid-Open No. 63-17981). Among them, an acrylic pressure-sensitive adhesive or a rubber pressure-sensitive adhesive is preferred. The pressure-sensitive adhesives may be used alone or in combination of two or more.

As the acrylic pressure-sensitive adhesive, for example, an acrylic pressure-sensitive adhesive using an acrylic polymer (homopolymer or copolymer) using one or two or more kinds of (meth) acrylic acid alkyl esters as a monomer component as a base polymer. Specific examples of (meth) acrylic acid alkyl esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (Meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isopropyl (meth) acrylate, (Meth) acrylate, undecyl (meth) acrylate, isodecyl (meth) acrylate, decyl (meth) acrylate, decyl (Meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate, etc. (Meth) arc of Lt; RTI ID = 0.0 > Cl-20 < / RTI > alkyl esters. Among them, (meth) acrylic acid alkyl ester having a straight chain or branched alkyl group having 4 to 18 carbon atoms can be preferably used.

The acrylic polymer may contain units corresponding to other monomer components copolymerizable with the (meth) acrylic acid alkyl ester, if necessary, for the purpose of modifying the cohesive force, heat resistance, crosslinkability and the like. Examples of such monomer components include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid and crotonic acid; Acid anhydride monomers such as maleic anhydride and itaconic anhydride; (Meth) acrylate, hydroxypropyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyhexyl ) Hydroxyl group-containing monomers such as hydroxylauryl acrylate and (4-hydroxymethylcyclohexyl) methyl methacrylate; Sulfonic acid groups such as styrenesulfonic acid, allylsulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, (meth) acrylamidopropanesulfonic acid, sulfopropyl (meth) acrylate, and (meth) acryloyloxynaphthalenesulfonic acid Containing monomer; (Meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol -Substituted) amide-based monomer; (Meth) acrylic acid aminoalkyl monomers such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate and t-butylaminoethyl (meth) acrylate; (Meth) acrylic acid alkoxyalkyl monomers such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate; Maleimide-based monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide and N-phenylmaleimide; N-diisopropylethylenediamine, N-methylethylenediamine, N-methylethylenediamine, N-methylethylenediamine, N-methylethylenediamine, N-methylethylenediamine, Itaconimide-based monomers such as N, N-lauryl itaconimide; (Meth) acryloyloxymethylenesuccinimide, N- (meth) acryloyl-6-oxyhexamethylenesuccinimide, N- (meth) acryloyl-8- Succinimide monomer; Vinyl pyrrolidone, vinyl pyrrolidone, vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinylpiperazine, vinyl pyrazine, vinyl pyrrole, vinyl imidazole, vinyl oxazole, vinyl Vinyl monomers such as morpholine, N-vinylcarboxylic acid amides, styrene,? -Methylstyrene, and N-vinylcaprolactam; Cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; An epoxy group-containing acrylic monomer such as glycidyl (meth) acrylate; Glycol acrylate monomers such as (meth) acrylic acid polyethylene glycol, (meth) acrylic acid polypropylene glycol, (meth) acrylic acid methoxyethylene glycol and (meth) acrylic acid methoxypolypropylene glycol; Acrylate monomer having a heterocycle such as tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate or silicone (meth) acrylate, halogen atoms, silicon atoms and the like; (Meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, (poly) ethylene glycol di (Meth) acrylate, trimethylol propane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy acrylate, polyester acrylate, and urethane acrylate Monomers; Olefinic monomers such as isoprene, butadiene and isobutylene; And vinyl ether-based monomers such as vinyl ether. These monomer components may be used singly or in combination of two or more kinds.

Examples of the rubber-based pressure-sensitive adhesive include natural rubber; Butadiene rubber, styrene-butadiene rubber, styrene-isoprene rubber, styrene-isoprene-styrene block copolymer (SIS) rubber, styrene-butadiene styrene block copolymer (SBS) Butadiene rubber, styrene-butadiene-styrene block copolymer (SEBS) rubber, styrene-ethylene-propylene-styrene block copolymer (SEPS) rubber, styrene-ethylene-propylene block copolymer (SEP) , Synthetic rubber such as these modified products, and the like may be mentioned.

The pressure-sensitive adhesive may contain any suitable additives, if necessary. Examples of the additives include crosslinking agents, tackifiers, plasticizers (e.g., trimellitic acid ester plasticizers, pyromellitic acid ester plasticizers), pigments, dyes, fillers, antioxidants, conductive materials, antistatic agents, ultraviolet Absorbents, light stabilizers, peel adjusters, softeners, surfactants, flame retardants, and antioxidants.

As the tackifier, any suitable tackifier is used. As the tackifier, for example, a tackifier resin is used. Specific examples of the tackifier resin include rosin-based tackifying resins (for example, unmodified rosin, modified rosin, rosin phenol-based resin, rosin ester-based resin and the like), terpene-based tackifying resins (for example, (For example, aliphatic hydrocarbon resins, aliphatic cyclic hydrocarbon resins, and aromatic hydrocarbon resins (for example, aliphatic hydrocarbon resin, aromatic hydrocarbon resin, or aromatic hydrocarbon resin), a terpene type phenolic resin, a terpene type phenolic resin, a styrene type modified terpene type resin, an aromatic modified terpene type resin, Aliphatic and alicyclic petroleum resins, aliphatic and alicyclic petroleum resins, hydrogenated hydrocarbon resins, coumarone resins, coumarone-indene resins and the like), phenolic tackifier resins (for example, styrene resins and xylene resins) For example, an alkylphenol resin, a xylene formaldehyde resin, a resole, a novolak, etc.), a ketone-based tackifying resin, a polyamide-based tackifying resin, an epoxy- Tackifying resins, and elastomer-based tackifying resins. Among them, rosin-based tackifying resin, terpene-based tackifying resin or hydrocarbon-based tackifying resin (styrene type resin, etc.) are preferable. The tackifiers may be used alone or in combination of two or more.

Commercially available products may be used as the tackifier. Specific examples of commercially available tackifiers include terpene phenol resins such as "YS POLYSTAR S145" and "MYTHES K140" available from Yasuhara Chemical Co., Ltd. and "Tamanol 901" available from Arakawa Chemical Industries, Ltd.; Sumilite Resin PR-12603 " manufactured by Sumitomo Bakelite Co., Ltd., rosin phenol resin such as " Tamanol 361 " manufactured by Arakawa Chemical Industries, Ltd., Alkylphenol resins such as "Tamanol 1010R" and "Tamanol 200N" manufactured by Arakawa Chemical Industries, Ltd.; And alicyclic saturated hydrocarbon resins such as "Alcon P-140" (trade name) manufactured by Arakawa Chemical Industries, Ltd.

The amount of the tackifier to be added is preferably 5 parts by weight to 100 parts by weight, more preferably 10 parts by weight to 50 parts by weight, based on 100 parts by weight of the base polymer.

Examples of the cross-linking agent include, in addition to an isocyanate-based cross-linking agent, an epoxy-based cross-linking agent, a melamine-based cross-linking agent and a peroxide-based cross-linking agent, urea cross-linking agents, metal alkoxide cross-linking agents, metal chelate cross-linking agents, metal salt cross- Based crosslinking agents, aziridine-based crosslinking agents, and amine-based crosslinking agents. Among them, an isocyanate crosslinking agent or an epoxy crosslinking agent is preferable.

Specific examples of the isocyanate crosslinking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; Cycloaliphatic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate; Aromatic isocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate and xylylene isocyanate; Trimethylolpropane / tolylene diisocyanate trimer adduct (trade name "Coronate L" manufactured by Nippon Polyurethane Industry Co., Ltd.), trimethylolpropane / hexamethylene diisocyanate trimer adduct (available from Nippon Polyurethane Industry Co., Ltd., Coronate HL And isocyanate adducts of hexamethylene diisocyanate (Nippon Polyurethane High Co., Ltd., trade name " Coronate HX "). The content of the isocyanate-based crosslinking agent may be set to any appropriate amount depending on the desired adhesive force, and is typically 0.1 to 20 parts by weight, more preferably 0.5 to 20 parts by weight, per 100 parts by weight of the base polymer 10 parts by weight.

Examples of the epoxy cross-linking agent include N, N, N ', N'-tetraglycidyl-m-xylenediamine, diglycidyl aniline, 1,3-bis (N, N-glycidylaminomethyl ), Cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name " Tertor C ", 1,6-hexanediol diglycidyl ether (manufactured by Kyowa Chemical Co., Ethylene glycol diglycidyl ether (trade name: "Epolite 40E" manufactured by Kyowa Chemical Co., Ltd.), propylene glycol diglycidyl ether (trade name: "Epolite 1500NP" EPICOL E-400 "), polypropylene glycol diglycidyl ether (Nichia analogue, trade name, manufactured by Nippon Kayaku Co., Ltd., product name:" Epolite 70P "), polyethylene glycol diglycidyl ether "Epiol P-200"), sorbitol polyglycidyl ether (trade name "Denacol EX-611" manufactured by Nagase Chemtex Co., Ltd.) (Trade name " Denacol EX-314 "), pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether (trade name, available from Nagase ChemteX, -512 "), sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris (2-hydroxy Ethylhexyl isocyanurate, resorcine diglycidyl ether, bisphenol-S-diglycidyl ether, epoxy resin having two or more epoxy groups in the molecule, etc. The content of the epoxy crosslinking agent It may be set to any suitable amount depending on the adhesive force, and is typically 0.01 to 10 parts by weight, more preferably 0.03 to 5 parts by weight, based on 100 parts by weight of the base polymer.

(Thermally expandable microspheres)

As the thermally expandable microspheres, any suitable thermally expandable microspheres that can be expanded or foamed by heating can be used. As the thermally expandable microspheres, for example, microspheres in which a substance that easily expands by heating is contained in a shell having elasticity can be used. Such thermally expandable microspheres can be produced by any appropriate method, for example, a coacervation method, an interfacial polymerization method, or the like.

Examples of the substance which can be easily expanded by heating include halogenated hydrocarbons such as propane, propylene, butene, normal butane, isobutane, isopentane, neopentane, n-pentane, n-hexane, isohexane, heptane, octane, Low-boiling liquids such as cargo, tetraalkylsilane and the like; And azodicarbonamide which is gasified by pyrolysis.

Examples of the material constituting the shell include nitrile monomers such as acrylonitrile, methacrylonitrile,? -Chloracrylonitrile,? -Ethoxyacrylonitrile, and fumaronitrile; Carboxylic acid monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid and citraconic acid; Vinylidene chloride; Vinyl acetate; (Meth) acrylate, isobornyl (meth) acrylate, isobornyl (meth) acrylate, isobutyl (meth) acrylate, (Meth) acrylic acid esters such as hexyl (meth) acrylate, benzyl (meth) acrylate and? -Carboxyethyl acrylate; Styrene monomers such as styrene,? -Methyl styrene and chlorostyrene; Amide monomers such as acrylamide, substituted acrylamide, methacrylamide, and substituted methacrylamide, and the like. The polymer composed of these monomers may be a homopolymer or a copolymer. Examples of the copolymer include vinylidene chloride-methyl methacrylate-acrylonitrile copolymer, methyl methacrylate-acrylonitrile-methacrylonitrile copolymer, methyl methacrylate-acrylonitrile copolymer, Acrylonitrile-methacrylonitrile-itaconic acid copolymer, and the like.

As the thermally expandable microspheres, an inorganic foaming agent or an organic foaming agent may be used. Examples of the inorganic foaming agent include ammonium carbonate, ammonium hydrogencarbonate, sodium hydrogen carbonate, ammonium nitrite, sodium borohydride, and various azides. Examples of the organic foaming agent include chlorobenzene-based compounds such as trichloromonofluoromethane and dichloromonofluoromethane; Azo compounds such as azobisisobutyronitrile, azodicarbonamide, and barium azodicarboxylate; Hydrazine compounds such as para-toluenesulfonyl hydrazide, diphenylsulfone-3,3'-disulfonylhydrazide, 4,4'-oxybis (benzenesulfonylhydrazide) and allyl bis (sulfonylhydrazide); a semicarbazide-based compound such as p-toluenesulfonyl semicarbazide, 4,4'-oxybis (benzenesulfonyl semicarbazide); Triazole-based compounds such as 5-morpholyl-1,2,3,4-thiatriazole; N-nitroso compounds such as N, N'-dinitrosopentamethylenetetramine and N, N'-dimethyl-N, N'-dinitrosoterephthalamide.

A commercially available product may be used as the thermally expandable microspheres. Specific examples of thermally expandable microspheres of commercially available products include Matsumoto Microsphere (grade: F-30, F-30D, F-36D, F-36LV, F-50, F- F-180D, F-190D, F-190D, F-260D and F-2800D manufactured by NIPPON FERRITE CO., LTD. (Grades: H750, H850, H1100, S2320D, S2640D, M330, M430, M520) manufactured by Kureha Chemical Industries, Ltd., (Grades: EML101, EMH204, EHM301, EHM302, EHM303, EM304, EHM401, EM403, and EM501) manufactured by Kakugo Kagyo Co., Ltd., and the like.

The particle size of the heat-expandable microspheres prior to heating is preferably 0.5 to 80 탆, more preferably 5 to 45 탆, further preferably 10 to 20 탆, particularly preferably 10 to 20 탆, 15 mu m. Therefore, the particle size of the heat-expandable microspheres prior to heating is preferably from 6 탆 to 45 탆, and more preferably from 15 탆 to 35 탆, in terms of the average particle diameter. The particle diameter and the average particle diameter are values obtained by the particle size distribution measurement method in the laser scattering method.

The thermally expandable microspheres preferably have an appropriate strength not ruptured until the volume expansion rate is preferably 5 times or more, more preferably 7 times or more, and even more preferably 10 times or more. When such thermally expandable microspheres are used, the adhesive force can be effectively lowered by the heat treatment.

The content of the thermally expandable microspheres in the pressure-sensitive adhesive region can be appropriately set in accordance with the lowering of the desired adhesive force and the like. The content of the thermally expandable microspheres is, for example, 1 part by weight to 150 parts by weight, preferably 10 parts by weight to 130 parts by weight, more preferably 25 parts by weight, relative to 100 parts by weight of the base polymer forming the pressure- To 100 parts by weight.

D. Substrate

Examples of the base material include a resin sheet, a nonwoven fabric, a paper, a metal foil, a woven fabric, a rubber sheet, a foamed sheet, and a laminate (particularly, a laminate including a resin sheet). Examples of the resin constituting the resin sheet include a resin such as a polyethylene terephthalate (PET), a polyethylene naphthalate (PEN), a polybutylene terephthalate (PBT), a polyethylene (PE), a polypropylene (PP), an ethylene- (EVA), polyamide (nylon), all aromatic polyamide (aramid), polyimide (PI), polyvinyl chloride (PVC), polyphenylene sulfide (PPS) Ether ether ketone (PEEK) and the like. Examples of the nonwoven fabric include nonwoven fabrics made of natural fibers having heat resistance such as nonwoven fabric including manila hemp; Nonwoven fabrics such as polypropylene resin nonwoven fabric, polyethylene resin nonwoven fabric, and ester based nonwoven fabric.

The thickness of the substrate may be set to any suitable thickness depending on the desired strength or flexibility, and the intended use. The thickness of the substrate is preferably 1000 占 퐉 or less, more preferably 1 占 퐉 to 1000 占 퐉, still more preferably 1 占 퐉 to 500 占 퐉, particularly preferably 3 占 퐉 to 300 占 퐉, 5 탆 to 250 탆.

The substrate may be subjected to a surface treatment. Examples of the surface treatment include corona treatment, chromic acid treatment, ozone exposure, flame exposure, high-voltage exposure, ionizing radiation treatment, and coating treatment with a primer. By performing such a surface treatment, the adhesion property between the covering material region and the substrate can be enhanced. Particularly, the coating treatment with the organic coating material is preferable because it enhances the adhesion and also makes it difficult for the coating material area to be destroyed at the time of heat peeling.

Examples of the organic coating material include materials described in, for example, Plastic Hard Coating Material II (CMC Publishing (2004)). Preferably, a urethane-based polymer, more preferably a polyacryl urethane, a polyester urethane or a precursor thereof is used. This is because it is easy to apply and apply the base material to the base material, and it is possible to industrially select a large number of such materials and obtain the base material at low cost. The urethane polymer is, for example, a polymer comprising a reaction mixture of an isocyanato monomer and an alcoholic hydroxyl group-containing monomer (for example, a hydroxyl group-containing acrylic compound or a hydroxyl group-containing ester compound). The organic coating material may contain, as an optional additive, a chain extender such as polyamine, an anti-aging agent, an oxidation stabilizer, and the like. The thickness of the organic coating layer is not particularly limited. For example, the thickness of the organic coating layer is suitably about 0.1 탆 to 10 탆, preferably about 0.1 탆 to 5 탆, and more preferably about 0.5 탆 to 5 탆.

E. Manufacturing method of adhesive sheet

The pressure-sensitive adhesive sheet of the present invention can be produced, for example, by (1) applying the pressure-sensitive adhesive on a release film (release paper) to form a pressure-sensitive adhesive application layer, (2) a method for forming a pressure-sensitive adhesive region-containing composition comprising the pressure-sensitive adhesive and heat-expandable microspheres on a release film; (3) a method in which the pressure-sensitive adhesive is applied on a release film to form a pressure-sensitive adhesive application layer, and then the pressure-sensitive adhesive application layer The release film is peeled off and the thermally expandable microspheres are pressed from the side (pressure-sensitive adhesive surface) side opposite to the covering material region of the pressure-sensitive adhesive application layer, A method for embedding a result, (4) to form a coating material region on a release film, to install the heat-expandable microspheres on one side, and the like can be mentioned a method of applying an adhesive on the side that the installation. In the above methods (1) to (4), by drying the pressure sensitive adhesive application layer formed by applying the pressure sensitive adhesive, the pressure sensitive adhesive region can be formed, but the drying can be performed at any appropriate timing. The drying may be performed before or after the thermally expandable microspheres are embedded. Further, it may be before or after forming the covering material region. When the thermally expandable microspheres are dried after being filled, it is preferable that the thermally expandable microspheres are dried at a temperature that is difficult to expand or foam. After the operations shown in (1) and (2) above, the release film may be peeled off, or the adhesive surface may be protected while leaving the release film until the adhesive sheet is provided for practical use.

When the adhesive sheet of the present invention is provided with a base material, the adhesive sheet is provided on a surface (opposite to the adhesive surface) opposite to the adhesive agent region of the covering material region after the operations (1) to (4) Can be obtained by adhering the substrate through any suitable adhesive or pressure-sensitive adhesive. Furthermore, a laminate of a base material and a covering material region, a laminate of a release film and a pressure-sensitive adhesive region (or a pressure-sensitive adhesive application layer) may be separately manufactured and these laminate may be bonded.

As the method of forming the covering material region, there can be mentioned (i) a method of thermally melting the polymer material or the resin material described in the above (B) to obtain a molded article in the form of a film by extrusion molding and then pressing the molded article in the pressure- (Ii) a method in which a resin solution containing the polymer material or resin material is applied to the pressure-sensitive adhesive region (or the pressure-sensitive adhesive application layer) or the substrate and then dried; (iii) A composition for forming a coating material region containing a monomer, oligomer or macromer capable of forming a resin material is applied to the pressure sensitive adhesive region (or the pressure sensitive adhesive application layer) or the substrate to polymerize the composition for forming the covering region , Heating, polymerization by irradiation with active energy rays, etc.). According to the method (iii), the amount of solvent and / or thermal energy used can be reduced. Further, in the method (ii), the resin solution may be coated on another release film, and then dried to obtain a film-shaped molded article, and then the molded article may be laminated on the pressure-sensitive adhesive area (or pressure- do. Further, in the method (iii), the composition for forming the coating material region is applied on another release film, and then dried to form a coating material region precursor, and the precursor is applied to the pressure sensitive adhesive region (or the pressure sensitive adhesive application layer) May be laminated, and then polymerized.

For example, in the method (iii), when a covering material region composed of an epoxy polymer is formed, 2,2- (4-hydroxyphenyl) propane diglycidyl ether, bis (4-hydroxy Phenyl) methane, and a suitable curing agent, followed by heating (for example, 60 to 120 ° C) may be employed.

For example, in the method of (iii), when a covering material region composed of a urethane polymer is formed, an isocyanate compound such as tolylene diisocyanate or hexamethylene diisocyanate and a polyol compound such as polyether polyol or polyester polyol (For example, 60 ° C to 120 ° C) after applying the composition for forming the coating material region containing the above-mentioned coating liquid.

For example, in the case of (iii), when a covering material region composed of a vinyl polymer is formed, a composition for forming a covering material region containing a vinyl compound such as vinyl chloride, styrene, and any suitable initiator may be used have.

The composition for forming the covering material region may contain additives such as an initiator, a catalyst, an ultraviolet absorber, and an antioxidant, if necessary. The beads may be included.

When the covering material region is made of a resin material that can be cured by irradiation of an active energy ray, an active energy ray is irradiated at any appropriate timing to obtain a pressure-sensitive adhesive sheet. The irradiation of the active energy ray is carried out after, for example, adherend (workpiece) is adhered. The irradiation of the active energy ray may be performed stepwise. For example, the adherend may be semi-cured before the adherend is adhered, and then cured after adhered. The kind and irradiation amount of the active energy ray can be set to any suitable kind and amount depending on the type of the resin material constituting the covering material region.

According to the above production method, the surface of the release film side (opposite to the covering material region) of the pressure sensitive adhesive region becomes an adhesive surface. Since the adhesive surface is formed in contact with the release film, the thermally expandable microspheres do not protrude and are flat. On the other hand, on the surface opposite to the adhesive surface of the pressure-sensitive adhesive region, the thermally expandable microspheres protrude. In the present invention, since the protruding thermo-expandable microspheres are covered by the covering material region, both sides of the pressure-sensitive adhesive sheet become flat, whereby the thickness of the pressure-sensitive adhesive region can be reduced. Such a pressure-sensitive adhesive sheet of the present invention can contribute to excellent cutting precision and reduction of cutting chips as a temporary fixing sheet when cutting electronic parts and the like.

F. Usage of adhesive sheet (manufacturing method of electronic parts)

According to another aspect of the present invention, a method of manufacturing an electronic component is provided. The method for manufacturing an electronic part of the present invention comprises adhering an electronic component material (substrate) obtained in a large area on the adhesive sheet and cutting the electronic component material.

Examples of the electronic component include a component for a semiconductor device such as a silicon wafer; Laminated capacitors: transparent electrodes, and the like.

In the above manufacturing method, first, the adhesive sheet is placed on a processing table and an electronic component material obtained in a large area is adhered on the adhesive sheet.

Thereafter, the electronic component material is cut by any appropriate method so that an electronic component can be obtained. Examples of the cutting method include a method using a blade such as a rotary blade or a flat blade, a method using a laser beam, and the like. In the case where the electronic component material is cut by forcing using a flat blade, generation of cutting chips is suppressed, and the yield is improved. In the present invention, since the pressure sensitive adhesive region can be made thinner, even if the electronic component material is cut by pressing in a planar state, chips after cutting are reattached, the cut surface becomes oblique or becomes unstable, It is possible to prevent the incidence of incisions and the like. Further, in the present invention, even when cutting is performed using a thin blade, the above effect can be obtained, and the manufacturing loss (loss due to the gap generated between chips after cutting) caused by the blade thickness can be reduced have. In the production of a more miniaturized electronic component, since the number of cut surfaces is large, the present invention capable of reducing the manufacturing loss as described above is particularly useful.

In the cutting process, cutting may be performed under heating. For example, the processing table may be heated to 30 to 150 DEG C to perform cutting processing.

(Example)

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited to these examples. The evaluation method in the examples is as follows. In the examples, " part " and "% " are by weight unless otherwise specified.

(1) Measurement of the thickness of the adhesive region and the covering material region by Raman mapping

The pressure-sensitive adhesive sheets obtained in Examples 1 to 3, 5, 6 and 12 to 15 were sectioned with a microtome to prepare measurement samples. The cross section of the measurement sample was subjected to spectral analysis by Raman spectroscopy using alpha300RSA manufactured by WITEC Co., and the peak derived from the component added only to the coating material region (for example, the peak of the active energy ray-reactive oligomer (UV1700B) 1640 cm < ^-1 >), the thicknesses of the coating material area and the pressure sensitive adhesive area were measured. As a representative example of the third embodiment, the Raman mapping in the measurement is shown in FIG. It is preferable that the surface where the abundant amount of components added to only the covering material region is clearly different is defined as the interface 1 and the distance from the adhesive surface 11 to the interface 1 is defined as the thickness of the adhesive region, The distance to the opposite surface 21 was defined as the thickness of the covering material region.

The measurement conditions of the Raman mapping measurement are as follows.

Excitation wavelength: 532 nm

Measurement wave range: 300 to 3600 cm ^-1

· Grating: 600gr / mm

· Objective lens: x100

Measurement time: 0.2 sec / 1 spectrum

· Measuring range: 20x40㎛

· Number of measurements: 100x200 points

· Detector: EMCCD

(2) Measurement of the thickness of the pressure-sensitive adhesive area and the covering material area with SEM

The pressure-sensitive adhesive sheets obtained in Examples 4, 7 to 11, 16 and 17 and Comparative Example 1 were cut with a trimming cutter in the thickness direction and subjected to Pt-Pd sputtering treatment. The cut surfaces were then subjected to S3400N low-vacuum injection by Hitachi High Technologies And the distance from the adhesive surface 11 to the interface 1 is set to be equal to the thickness of the adhesive material area and the thickness of the adhesive layer from the interface 1 to the opposite side to the adhesive surface The surface 21 was defined as the thickness of the covering material area. As a representative example of Example 11, a cross-sectional SEM image of the pressure-sensitive adhesive sheet is shown in Fig.

The measurement conditions of the SEM observation are as follows.

· Observation: ESED Award

· Acceleration voltage: 10 kV

· Magnification: 600 times

(3) Measurement of elastic modulus

The pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples were cut in the thickness direction using a microtome, and the elastic modulus of the cut surfaces was measured with a nanoindenter.

More specifically, with respect to the covering material region, the surface of the covering material region (surface opposite to the adhesive surface), which is substantially perpendicular to the cutting surface, and the cut surface surface spaced about 3 탆 from the surface were measured. The elastic modulus was obtained by numerically treating the displacement-load hysteresis curve obtained by pressing the probe (indenter) against the measurement object with the triboscan of the measuring apparatus unit. In Table 1, the modulus of elasticity measured on the surface of the cut surface 3 mu m apart from the surface (average value of three measurements) is shown.

The nanoindenter device and measurement conditions are as follows.

Device and measurement conditions

Device: Nanoindenter; Triboindenter, manufactured by Hysitron Inc

· Measurement method: Single pressure method

· Measuring temperature: 25 ℃

Pressing speed: about 1000 nm / sec

· Indentation depth: about 800 nm

· Probe: Diamond type, Berkovich type (triangular shape)

(4) Adhesion measurement

(Adhesion before heating (before expanding thermally expandable microspheres)

The pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples were cut into a size of a width of 20 mm and a length of 140 mm, and a polyethylene terephthalate film (trade name: Lumirror S-10, manufactured by Toray Co., : 25 mu m, width: 30 mm) was left in the width direction at a distance of 5 mm, and a 2 kg roller was reciprocated one by one according to JIS Z 0237: 2009 to prepare a measurement sample. The measurement sample was set in a tensile tester (product name: Shimadzu Autograph AG-120kN, manufactured by Shimadzu Seisakusho Co., Ltd.) equipped with a thermostat, and left for 30 minutes. Thereafter, the load was measured when the adherend was peeled from the adhesive sheet in the longitudinal direction under the conditions of a peeling angle of 180 ° and a peeling speed (tensile speed) of 300 mm / min. The maximum load at that time (N / 20 mm width) was obtained by dividing the peak load by the tape width. The above operation was performed in an atmosphere of a temperature of 23 占 占 폚 and a humidity of 65 占% RH.

(Adhesion after heating (after expanding or foaming the thermally expandable microspheres)

A test sample was prepared in the same manner as described above, and the test sample was introduced into a hot air dryer. After standing for 1 minute under the maximum expansion temperature (to be described later) of the thermally expandable microspheres in the hot-air dryer, the adherend was peeled off in the same manner as above, and the adhesive force was measured. The operation before and after the introduction into the hot air dryer was performed in an atmosphere of a temperature of 23 占 占 폚 and a humidity of 65 占% RH.

(5) Surface roughness measurement

With respect to the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples, the surface roughness (Ra) of the pressure-sensitive adhesive surface was measured after the thermally expandable microspheres were expanded or foamed. Expansion or foaming of the thermally expandable microspheres was carried out in a hot air drier under a condition of 1 minute at the maximum expansion temperature (to be described later) of the thermally expandable microspheres. The measurement of the surface roughness was performed with a laser microscope "OLS4000" manufactured by Olympus.

(6) Evaluation of separation of small pieces after cutting

A laminated ceramic sheet of 40 mm x 50 mm (thickness 500 mu m) was bonded to the pressure-sensitive adhesive sheet obtained in Examples and Comparative Examples. The laminated ceramic sheet on the pressure-sensitive adhesive sheet was cut into dice so as to be a piece of 1 mm x 0.5 mm with a cutting device "G-CUT8AA" manufactured by UHT. The laminated ceramic sheet on the pressure-sensitive adhesive sheet was provided along the side surface of a cylinder having a diameter of 30 mm. Heat treatment is performed at a predetermined temperature (maximum expansion temperature of the thermally expandable microspheres (described later)) in a state of being installed in a cylinder, and the thermally expandable microspheres are expanded to separate the pieces from the pressure-sensitive adhesive sheet, The number of chips not counted. The number obtained by dividing the number of chips that were not separated by the number of chips when 100% was completely separated was taken as an index of separability. The index is less than 2% ◎, the indicator is more than 2% and less than 5% ○, the indicator is more than 5% and less than 15%, and the indicator is more than 15%.

Details of the composition of the laminated ceramic sheet and the cutting conditions of the cutting apparatus are as follows.

(Laminated ceramic sheet)

100 parts of barium titanate powder, 15 parts of polyvinyl butyral resin, 6 parts of bis (2-ethylhexyl) phthalate and 2 parts of diglycerin stearate were added to a toluene solvent and mixed and dispersed in a ball mill disperser to prepare a dielectric toluene Solution. This solution was applied to the surface of a silicon release agent-treated surface of a polyethylene terephthalate film (product name: "MRF38", trade name, manufactured by Mitsubishi Polyester Film Co., Ltd., thickness: 38 μm) equipped with a silicon release agent-treated surface to a thickness of 50 μm after solvent volatilization using an applicator And dried to obtain a ceramic sheet. A plurality of the obtained ceramic sheets were laminated so as to have a thickness of 500 mu m to obtain a laminated ceramic sheet.

(Cutting condition)

Cutting temperature: 60 ° C, cutting depth (amount remaining from the table surface): about 20 μm

Cutting blade: "U-BLADE2" manufactured by UHT, blade thickness: 50 μm, blade angle: 15 °

(7) Evaluation of cut surface cut-off property

In the same manner as in (6) above, the laminated ceramic sheet was cut into dice so as to be a piece of 1 mm x 0.5 mm. Ten arbitrary cut pieces were selected, and the cut surfaces were observed with a magnifying glass having a magnification factor of 50 to confirm whether chipping (cut-out of the laminated ceramic sheet caused by the cutting process) was present or not. As the index. A score of 0 to less than 10 on the index, a score of less than 20 on the score of 10 or more, a score of less than 40 on the score of 20 or more, and a score of 40 or more.

The polymer preparation method is described below. Also, here, unless otherwise specified, the weight shall be regarded as the weight.

[Preparation Example 1] Preparation of polymer 1

100 parts of butyl acrylate, 5 parts of acrylic acid and 0.2 part of benzoyl peroxide as a polymerization initiator were added to toluene and heated to obtain a toluene solution of an acrylic copolymer (polymer 1).

[Preparation Example 2] Preparation of polymer 2

30 parts of 2-ethylhexyl acrylate, 70 parts of ethyl acrylate, 4 parts of 2-hydroxyethyl acrylate, 5 parts of N-phenylmaleimide and 0.2 parts of benzoyl peroxide as a polymerization initiator were added to toluene , And heated to obtain a toluene solution of an acrylic copolymer (polymer 2).

[Preparation Example 3] Preparation of polymer 3

30 parts of 2-ethylhexyl acrylate, 70 parts of ethyl acrylate, 4 parts of 2-hydroxyethyl acrylate, 5 parts of methyl methacrylate and 0.2 part of benzoyl peroxide as a polymerization initiator were added to toluene, And heated to obtain a toluene solution of an acrylic copolymer (polymer 3).

[Preparation Example 4] Preparation of polymer 4

50 parts of butyl acrylate, 50 parts of ethyl acrylate, 5 parts of acrylic acid, 0.1 part of 2-hydroxyethyl acrylate and 0.2 part of benzoyl peroxide as a polymerization initiator were added to toluene and heated to obtain an acrylic copolymer (Polymer 4) in toluene.

[Preparation Example 5] Preparation of polymer 5

70 parts of methyl acrylate, 30 parts of 2-ethylhexyl acrylate, 10 parts of acrylic acid, and 0.2 part of benzoyl peroxide as a polymerization initiator were added to ethyl acetate, and the mixture was heated to obtain ethyl acetate (polymer 5) Solution.

[Preparation Example 6] Preparation of polymer 6

50 moles of butyl acrylate, 50 moles of ethyl acrylate, 22 moles of 2-hydroxyethyl acrylate, and 20 g of benzoyl peroxide (butyl acrylate, ethyl acrylate and 2-hydroxyethyl acrylate 0.2 part based on 100 parts in total) was added and heated to obtain a copolymer solution. To this copolymer solution, 2-isocyanatoethyl acrylate in an amount corresponding to 80 mol% of hydroxyl groups derived from 2-hydroxyethyl acrylate in the solution was added and then heated to obtain the corresponding 2-hydroxy By adding 2-isocyanatoethyl methacrylate to the hydroxyl group derived from ethyl acrylate, a toluene solution of an acrylic copolymer (polymer 6) having a methacrylate group in its side chain was obtained.

[Preparation Example 7] Preparation of polymer 7

Into toluene, 80 moles of butyl acrylate, 30 moles of acryloylmorpholine, 20 moles of 2-hydroxyethyl acrylate, and 20 g of benzoyl peroxide (butyl acrylate, acryloylmorpholine, and 2-hydroxy Ethyl acrylate) was added, and the mixture was heated to obtain a copolymer solution. To this copolymer solution, 2-isocyanatoethyl acrylate in an amount corresponding to 50 mol% of hydroxyl groups derived from 2-hydroxyethyl acrylate in the solution was added and then heated to obtain the corresponding 2-hydroxy By adding 2-isocyanatoethyl methacrylate to the hydroxyl group derived from ethyl acrylate, a toluene solution of an acrylic copolymer (polymer 7) having a methacrylate group in its side chain was obtained.

[Example 1]

(Formation of pressure-sensitive adhesive layer precursor layer)

(Polymer 2: 100 parts) of the polymer 2 prepared in Production Example 2 and 1 part of an isocyanate crosslinking agent (trade name: Coronate L, trade name, manufactured by Nippon Polyurethane Co., Ltd.) and a terpene phenol resin Matsumoto Microsphere F-50D "manufactured by Matsumoto Yushi Co., Ltd., expansion (expansion) starting temperature: 95 ° C to 105 ° C, maximum temperature: Expansion temperature: 125 DEG C to 135 DEG C, average particle diameter 10 mu m to 18 mu m) were mixed to prepare a mixed solution. The viscosity of the mixed liquid was adjusted to the viscosity where the same solvent (toluene) as that of the solvent in the mixed liquid was further added to facilitate application. The mixed solution was applied to a polyethylene terephthalate film (product name: "MRF38", manufactured by Mitsubishi Chemical Corporation, thickness: 38 μm) with a silicon release agent-treated surface so as to have a thickness of 10 μm after solvent volatilization And then dried to form a pressure-sensitive adhesive region precursor layer on the polyethylene terephthalate film.

(Formation of coating material area precursor layer)

A mixture of dipentaerythritol penta and hexaacrylate (trade name: Aronix M404, manufactured by Toagosei Co., Ltd.) as an active energy ray-reactive oligomer 20 (polymer 1: 100 parts) , 2 parts of an isocyanate-based crosslinking agent (trade name: Coronate L, trade name, manufactured by Nippon Polyurethane Co., Ltd.) and 3 parts of an energy ray polymerization initiator (trade name: Irgacure 651, manufactured by BASF Japan) were mixed to prepare a mixed solution. The viscosity of the mixed liquid was adjusted to the viscosity where the same solvent (toluene) as that of the solvent in the mixed liquid was further added to facilitate application. (Thickness: 38 占 퐉) having a thickness of 25 占 퐉 was applied to a polyethylene terephthalate film (manufactured by Mitsubishi Kagaku Polyester Film Co., Ltd., trade name: MRF38, Thereafter, it was dried and a coating material area precursor layer was formed on the polyethylene terephthalate film.

(Formation of pressure-sensitive adhesive sheet 1)

The pressure-sensitive adhesive region precursor layer and the covering material region precursor layer were bonded. Subsequently, ultraviolet irradiation with an accumulated light quantity of 300 mJ / cm ^{2 was carried out from} the ultraviolet ray irradiator "UM810 (high pressure mercury lamp light source)" (manufactured by Nitto Seiki Co., Ltd.) from the side of the precursor layer of the coverage area. Thereafter, the polyethylene terephthalate film with the silicone release agent-treated surface was peeled off to obtain the pressure-sensitive adhesive sheet 1 (thickness of the pressure-sensitive adhesive area: 10 mu m, thickness of the covering area: 25 mu m).

[Examples 2 to 15, Comparative Example 1]

The types and blending amounts of the polymer, crosslinking agent, tackifier, and heat-expandable microspheres in forming the pressure-sensitive adhesive region precursor layer were set as shown in Table 1, and the polymer at the time of forming the coating material region precursor layer, the active energy ray- , The crosslinking agent, and the type and amount of the energy ray polymerization initiator were set as shown in Table 1, a pressure-sensitive adhesive sheet was obtained.

In Examples 2 to 5, 8, 10, 13 to 15 and Comparative Example 1, a PET film (thickness: 100 占 퐉) was used instead of a polyethylene terephthalate film having a silicone release agent- ), And a pressure-sensitive adhesive sheet having a PET film (substrate) was obtained without peeling off the PET film. In Example 4 and Comparative Example 1, a pressure-sensitive adhesive sheet was obtained without ultraviolet irradiation.

Details of the crosslinking agent, tackifier, thermoexpanding microsphere, active energy ray-reactive oligomer and energy ray polymerization initiator described in Table 1 are as follows.

<Cross-linking agent>

TETRAD C, manufactured by Mitsubishi Gas Chemical Company, trade name &quot; TETRAD C &quot;, epoxy cross-linking agent

<Tackifier>

PR51732: Sumitomo Bakelite, trade name &quot; SUMILITE RESIN PR51732 &quot;

S145: manufactured by Yasuhara Chemical Co., Ltd., trade name: YS POLYSTAR S145

U130: manufactured by Yasuhara Chemical Co., Ltd., trade name: YS POLYSTAR U130

T160: product name "YS POLYSTAR T160" manufactured by Yasuhara Chemical Co., Ltd.

<Thermally expandable microspheres>

70 to 80 占 폚, maximum expansion temperature: 110 to 120 占 폚, average particle diameter 10 to 18 占 퐉 (F-30D)

105 to 115 占 폚, a maximum expansion temperature of 145 to 155 占 폚, an average particle diameter of 12 to 18 占 퐉,

FN-180SSD: Matsumoto Microsphere FN-180SSD manufactured by Matsumoto Yushi Seiyakuse Co., Ltd., foaming (expansion) start temperature 135 占 폚 to 150 占 폚, maximum expansion temperature 165 占 폚 to 180 占 폚, average particle diameter 15 占 퐉 to 25 占 퐉

F-260D: Matsumoto Microsphere F-260D manufactured by Mitsumoto Yushi Seiyakuse Co., Ltd. Foaming (Expansion) Initiation Temperature: 190 to 200 占 폚, Maximum Expansion Temperature: 250 to 260 占 폚,

&Lt; Active energy ray reactive oligomer &

UV1700B: manufactured by NIPPON KOSEI KAGAKU, trade name &quot; Varnish UV-1700B &quot;, ultraviolet curing type urethane acrylate

UV7620EA: manufactured by NIPPON KOSEI KAGAKU, trade name &quot; Magnetizing UV-7620EA &quot;, ultraviolet curable urethane acrylate

UV3000B: manufactured by NIPPON KOSEI KAGAKU, trade name &quot; Varnish UV-3000B &quot;, ultraviolet curing type urethane acrylate

M321: Aronix M321 manufactured by Toagosei Co., trimethylol propane PO modified triacrylate (average addition mol number of propylene oxide (PO): 2 moles)

UV7630B: manufactured by NIPPON KOSEI KAGAKU, trade name &quot; Magnetical UV-7630B &quot;, ultraviolet curable urethane acrylate

<Energy ray polymerization initiator>

I184: manufactured by BASF, trade name &quot; Irgacure 184 &quot;

I2959: manufactured by BASF, trade name &quot; Irgacure 2959 &quot;

I651: manufactured by BASF, trade name "Irgacure 651"

[Example 16]

, 0.8 part of a toluene solution of the polymer 1 prepared in Preparation Example 1 (polymer 1: 100 parts), an epoxy crosslinking agent (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name: Tertor C) and a terpene phenolic resin 30 parts of a thermally expandable microspheres (trade name &quot; Matsumoto MicroSpare F-50D &quot;, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.), foaming (expansion) starting temperature: 95 to 105 ° C (trade name: YS Polystar S145, manufactured by Yasuhara Chemical Co., , Maximum expansion temperature: 125 DEG C to 135 DEG C, average particle diameter 10 mu m to 18 mu m) were mixed to prepare a mixed solution. The viscosity of the mixed liquid was adjusted to the viscosity where the same solvent (toluene) as that of the solvent in the mixed liquid was further added to facilitate application. This mixed solution was applied to a polyethylene terephthalate film (product name: "MRF38", manufactured by Mitsubishi Kagaku Polyester Film Co., Ltd., thickness: 38 μm) equipped with a silicon release agent-treated surface so as to have a thickness of 30 μm after solvent volatilization And then dried to form a pressure-sensitive adhesive region precursor layer on the polyethylene terephthalate film.

The pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer precursor layer was bonded to the matte treated surface of a polyethylene terephthalate film (manufactured by Toray Co., Ltd., trade name &quot; Lumirror Type X42 &quot;, thickness: 50 m) as a covering material region with a hand roller. Autoclave treatment ^{(40 ℃, 5Kgf / cm 2} , 10 minutes) to obtain a pressure-sensitive adhesive sheet (pressure-sensitive adhesive area (thickness: 50㎛): 30㎛) / covering area (polyethylene terephthalate, thickness).

[Example 17]

(Polymer 4: 100 parts) of Polymer 4 prepared in Production Example 4 and 0.8 part of an epoxy crosslinking agent (manufactured by Mitsubishi Gas Kagaku Co., Ltd., trade name &quot; Tertor C &quot;) and a terpene phenolic resin 5 parts of a thermally expandable microspheres (Matsumoto Microsphere F-50D, manufactured by Matsumoto Yushi Seiyaku Co., Ltd., foaming (expansion) start temperature: 95 to 105 deg. C (trade name: YS Polystar S145) , Maximum expansion temperature: 125 DEG C to 135 DEG C, average particle diameter 10 mu m to 18 mu m) were mixed to prepare a mixed solution. The viscosity of the mixed liquid was adjusted to the viscosity where the same solvent (toluene) as that of the solvent in the mixed liquid was further added to facilitate application. This mixed solution was applied to a polyethylene terephthalate film (product name: "MRF38", manufactured by Mitsubishi Kagaku Polyester Film Co., Ltd., thickness: 38 μm) equipped with a silicon release agent-treated surface so as to have a thickness of 40 μm after solvent volatilization And then dried to form a pressure-sensitive adhesive region precursor layer on the polyethylene terephthalate film.

(10th place) was added to one side of a polyethylene terephthalate film (PG-CHI (FG, thickness 200 占 퐉) manufactured by Mitsubishi Jushi Co., Ltd.) as a covering material region in a mixed solvent of ethyl acetate and dimethylformamide (Pressure-sensitive adhesive layer (pressure-sensitive adhesive layer (thickness (%)) of 1: 10 (volume%) was applied on the surface of the pressure sensitive adhesive layer to bond the adhesive surface of the pressure sensitive adhesive layer precursor layer to the applied surface with a hand roller. : 40 mu m) / covering material region (polyethylene terephthalate, thickness: 200 mu m).

As is clear from Table 1, the pressure-sensitive adhesive sheet of the present invention can lower the adhesive force by heating, and can realize excellent cutting precision when cutting an adherend.

The production method and the pressure-sensitive adhesive sheet of the present invention can be suitably used for the production of chip-shaped electronic components such as semiconductor chips.

10:
11: Adhesive face
12: Adhesive
13: Thermally expandable microsphere
20:
30: substrate
100, 200: pressure-sensitive adhesive sheet

Claims (8)

An adhesive surface whose adhesive force is lowered by heating only on one side,
And the elastic modulus by the nanoindentation method at 25 DEG C of the surface opposite to the adhesive surface is 1 MPa or more. The method according to claim 1,
A pressure sensitive adhesive layer having a pressure sensitive adhesive area including the pressure sensitive adhesive surface as a surface and a covering material area adjacent to the pressure sensitive adhesive surface opposite to the pressure sensitive adhesive surface,
Wherein the pressure sensitive adhesive region comprises a pressure sensitive adhesive and a thermally expansible microsphere. 3. The method according to claim 1 or 2,
Wherein the thickness of the pressure sensitive adhesive region is 50 占 퐉 or less. 4. The method according to any one of claims 1 to 3,
Wherein the adhesive force when the adhesive surface side is adhered to the polyethylene terephthalate film is 0.2 N / 20 mm or more. 5. The method according to any one of claims 1 to 4,
Wherein the ratio (a2 / a1) of the adhesive force (a1) before heating to the adhesive force (a2) after heating is 0.0001 to 0.5. 6. The method according to any one of claims 1 to 5,
Wherein the surface roughness (Ra) of the adhesive surface after heating is 3 占 퐉 or more. 7. The method according to any one of claims 1 to 6,
And a substrate on the side opposite to the adhesive surface. A method for producing a pressure-sensitive adhesive sheet, which comprises adhering an electronic component material onto the pressure-sensitive adhesive sheet according to any one of claims 1 to 7,
And cutting the electronic component material.

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