TWI659084B - Adhesive sheet - Google Patents

Abstract

The present invention provides an adhesive sheet that can achieve excellent cutting accuracy and reduction of cutting chips during cutting processing of small parts such as electronic parts.

The adhesive sheet of the present invention includes an adhesive layer containing a plurality of thermally expandable microspheres, and a captive layer disposed on one side of the adhesive layer, and at least one or more thermally expandable microspheres protrude from the adhesive layer. The prominent thermally expandable microspheres are buried in the captive layer. In a preferred embodiment, the adhesive layer contains thermally expandable microspheres having a particle diameter larger than the thickness of the adhesive layer.

Description

Adhesive sheet

The present invention relates to an adhesive sheet.

In the manufacture of electronic parts such as silicon wafers, multilayer capacitors, and transparent electrodes, the substrate obtained by cutting a large area and integrating the necessary functions at one time into a required size is cut down. When cutting, use an adhesive sheet for fixing the workpiece (substrate) to prevent the cutting accuracy from being reduced due to stress and vibration during processing. For this adhesive sheet, sufficient adhesion to the workpiece is required during processing, and it is required that the cut workpiece (electronic component) can be easily peeled off after processing. As such an adhesive sheet, an adhesive sheet containing heat-expandable microspheres in an adhesive is known (for example, Patent Document 1). The adhesive sheet containing heat-expandable microspheres reduces the adhesive force by expanding or expanding the heat-expandable microspheres by heating, so it can show sufficient adhesion during the above processing, and it is easy to heat it after processing. Ground the electronic parts.

In recent years, the lightness and miniaturization of electronic parts have been developed, and there is a demand for an adhesive sheet for fixing a workpiece that can be cut with higher accuracy. In addition, it is required to reduce machining chips (chips) generated during cutting. In response to these requirements, it is considered that if the adhesive constituting the adhesive sheet is made thin, an adhesive sheet that can achieve higher cutting accuracy and reduced chipping can be obtained. However, in the adhesive sheet containing thermally expandable microspheres, since the thermally expandable microspheres are contained, there is a problem that the thickness of the adhesive is limited. More specifically, in an adhesive sheet containing heat-expandable microspheres, if the adhesive is made thin, the heat-expandable microspheres protrude from the adhesive, and the practicality such as poor adhesion to a substrate or a processing table is obvious. Reduce the problem.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2002-121510

The present invention has been made in order to solve the foregoing problems, and an object thereof is to provide an adhesive sheet that can achieve excellent cutting accuracy and reduction of cutting chips during cutting processing of small parts such as electronic parts.

The adhesive sheet of the present invention includes an adhesive layer containing a plurality of thermally expandable microspheres, and a captive layer disposed on one side of the adhesive layer, and at least one or more thermally expandable microspheres protrude from the adhesive layer. The prominent thermally expandable microspheres are buried in the captive layer.

In a preferred embodiment, the adhesive layer contains thermally expandable microspheres having a particle diameter larger than the thickness of the adhesive layer.

In a preferred embodiment, a height of a portion of the thermally expandable microsphere protruding from the adhesive layer is 0.4 μm or more.

In a preferred embodiment, the length (l1) of the interface between the adhesive layer and the mooring layer and the length of the interface are observed under a cross-section of a specific area including a portion of the thermally expandable microsphere protruding from the adhesive layer. The ratio (l1 / L) of the length (L) of the projection line in the thickness direction is 1.02 or more.

In a preferred embodiment, the average particle diameter of the thermally expandable microspheres is 6 μm to 45 μm.

In a preferred embodiment, the elastic modulus of the tethered layer measured by the nanoindentation method at 25 ° C is 1 MPa or more.

In a preferred embodiment, the thickness of the adhesive layer is 20 μm or less.

In a preferred embodiment, the thermally expandable microspheres are expanded or foamed by heating. In this case, the surface roughness Ra of the surface of the adhesive layer on the side opposite to the mooring layer is 3 μm or more.

In a preferred embodiment, the elastic modulus of the adhesive layer measured by the nanoindentation method at 25 ° C is 1 MPa or less.

In a preferred embodiment, a substrate is further provided on the opposite side of the tethered layer from the adhesive layer.

According to another aspect of the present invention, a method for manufacturing an electronic component is provided. The manufacturing method includes: after attaching an electronic component material to the adhesive sheet, cutting the electronic component material.

According to the present invention, since the tether layer is disposed on one side of the adhesive layer containing the heat-expandable microspheres, the heat-expandable microspheres protruding from the adhesive layer are buried in the tether layer, which can be prevented from being caused by the heat-expandable microspheres. When the unevenness influences the thickness of the adhesive layer which is a low-elasticity region, it is possible to obtain an adhesive sheet capable of achieving excellent cutting accuracy. In addition, according to the present invention, since the adhesive layer can be made thin, if the micro-parts such as electronic parts are cut using the adhesive sheet of the present invention, generation of cutting chips can be suppressed.

1‧‧‧ interface

10‧‧‧ Adhesive layer

11‧‧‧ heat-expandable microspheres

12‧‧‧ Adhesive

20‧‧‧ Ties

30‧‧‧ substrate

100, 200‧‧‧ Adhesive sheet

H‧‧‧ height

L‧‧‧ length

l1‧‧‧ length

FIG. 1 is a schematic cross-sectional view of an adhesive sheet according to a preferred embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of an adhesive sheet according to a preferred embodiment of the present invention for explaining the interface between the adhesive layer and the tether layer.

3 is a schematic cross-sectional view of an adhesive sheet according to another preferred embodiment of the present invention.

FIG. 4 is a diagram showing a Raman image obtained by measuring the thickness in Example 3. FIG.

5 is a view showing a SEM (Scanning Electron Microscope) image of a cross section of the adhesive sheet in Example 11. FIG.

A. The overall composition of the adhesive sheet

FIG. 1 is a schematic cross-sectional view of an adhesive sheet according to a preferred embodiment of the present invention. The adhesive sheet 100 includes an adhesive layer 10 and a tether layer 20 disposed on one side of the adhesive layer 10. The adhesive layer 10 includes a plurality of thermally expandable microspheres 11. Practically, the adhesive layer 10 further includes an adhesive 12. At least one or more thermally expandable microspheres 11 protrude from the adhesive layer 10, and the protruding thermally expandable microspheres 11 are buried in the tethered layer 20 in a tethered manner. By embedding the protruding thermally expandable microspheres 11 in the mooring layer 20, the influence of the unevenness caused by the thermally expandable microspheres 11 can be eliminated. The heat-expandable microspheres 11 can be expanded or foamed by heating. Although not shown, until the adhesive sheet is put into practical use, a release paper may be disposed on the adhesive layer 10 to protect the adhesive layer 10. In the example shown in the figure, although the interface 1 between the adhesive layer 10 and the mooring layer 20 is clearly shown, the interface may be an interface that is difficult to distinguish by visual inspection, a microscope, or the like. Difficult interfaces such as visual observation and microscope can be used to identify the composition of each layer (see below for details).

In the present invention, the provision of the tethering layer 10 allows the thermally expandable microspheres 11 to protrude from the adhesive layer 10 and makes the adhesive layer 10 thin. When the adhesive layer 10 which is a low-elasticity region is thinned, it becomes a sheet | seat for temporary fixing at the time of a cutting process of an electronic component etc., and it contributes to the achievement of excellent cutting precision. More specifically, if an electronic part or the like is cut by using an adhesive sheet having a thin adhesive layer 10 as a temporary fixing sheet, since the adhesive sheet has less deformation, the following can be prevented: After the wafer is broken, the wafer is reattached; the cut surface becomes inclined or becomes S-shaped and becomes unstable; wafer defects occur during cutting. In addition, when an adhesive sheet having a relatively thin adhesive layer 10 is used as a temporary fixing sheet when cutting an electronic component or the like, generation of chips can be suppressed. The adhesive sheet of the present invention not only exerts the above-mentioned effect in the cutting by the rotary knife which is often used in the crystal cutting step, but also the cutting by the cutting by the flat knife to reduce the cutting loss. The above-mentioned effect is also exerted in the interruption, which is particularly useful. When cutting is performed under heating (for example, 30 ° C to 150 ° C), the cutting can be performed with high accuracy as described above.

Moreover, since the adhesive sheet 10 of this invention contains the thermally expansible microsphere 11, the adhesive sheet 10 contains When the adherend (for example, the wafer after the cutting process) is peeled from the adhered sheet, it is heated at a temperature at which the heat-expandable microspheres 11 can expand or foam to generate unevenness on the adhered surface, so that The adhesive force of the adhesive surface is reduced or disappeared.

The height H of the part of the thermally expandable microsphere protruding from the adhesive layer is preferably 0.4 μm or more, more preferably 0.4 μm to 80 μm, and still more preferably 0.6 μm to 80 μm. In the present invention, by providing a tethering layer, the thermally expandable microspheres can be allowed to protrude as high as described above, and the thickness of the adhesive layer can be made thin. In addition, if the height H is in the above range, it is possible to provide reduction in the strength and elastic modulus of the tether layer, and to provide a more excellent cutting as a temporary fixing sheet when cutting electronic parts and the like. Precision adhesive sheet. The height of the part of the thermally expandable microsphere protruding from the adhesive layer is preferably smaller than the thickness of the mooring layer.

The length (l1) of the interface between the adhesive layer and the mooring layer and the length (L) of the projection line in the thickness direction of the interface under the cross-sectional observation of a specific area containing the thermally expandable microspheres protruding from the adhesive layer. The ratio (l1 / L) is preferably 1.02 or more, and more preferably 1.05 to 5. In the present invention, by providing a tethering layer, the thermally expandable microspheres can be allowed to protrude in the interface shape as described above, and the thickness of the adhesive layer can be reduced. In addition, if (l1 / L) is within the above range, it can provide reduction in the strength and elastic modulus of the tether layer, and can be used as a temporary fixing sheet when cutting electronic parts and the like, which contributes to more excellent realization. Adhesive sheet with cutting accuracy. The thick solid line l1 shown in the schematic cross-sectional view of FIG. 2 is the interface between the adhesive layer and the mooring layer.

Adhesive force when the adhesive surface of the adhesive sheet of the present invention (that is, the surface of the adhesive layer on the side opposite to the mooring layer) is attached to a polyethylene terephthalate film (for example, a thickness of 25 μm) It is preferably 0.2N / 20mm or more, more preferably 0.2N / 20mm to 20N / 20mm, and still more preferably 2N / 20mm to 10N / 20mm. Within this range, an adhesive sheet useful as a sheet for temporary fixation when cutting an electronic component or the like can be obtained. In the present specification, the adhesive force refers to a method according to JIS Z 0237: 2000 (measurement temperature: 23 ° C, bonding conditions: 2 kg roller reciprocating once, peeling speed: 300mm / min, peeling angle 180 °). Measured adhesion.

The adhesive force of the adhesive surface of the adhesive sheet of the present invention after being adhered to a polyethylene terephthalate film (for example, 25 μm in thickness) is preferably 0.2N / 20mm or less, more preferably 0.1N / 20mm the following. In the present specification, the heating of the adhesive sheet refers to heating at a temperature and time for which the adhesive force is reduced by the expansion or foaming of the thermally expandable microspheres. This heating is performed, for example, at 70 ° C to 270 ° C for 1 minute to 10 minutes.

Adhesive force when the adhesive surface of the adhesive sheet of the present invention is attached to a polyethylene terephthalate film (e.g., 25 μm thick) (i.e., adhesive force before heating (a1)) and adhesive force after heating The ratio (a2 / a1) of (a2) 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, by heating the adhesive sheet of the present invention at a specific temperature, the surface of the adhesive layer opposite to the mooring layer (that is, the adhesive surface) is uneven. The surface roughness Ra of the adhesive surface after heating the adhesive sheet of the present invention is preferably 3 μm or more, and more preferably 5 μm or more. If it is such a range, the adhesive force will reduce or disappear after heating, and the adhesive sheet which can peel an adherend easily can be obtained. In addition, the surface roughness Ra of the adhesive surface refers to the surface roughness Ra of the adhesive surface of the adhesive sheet after being heated in the state where there is no adherend. The surface roughness Ra can be measured in accordance with JIS B 0601: 1994.

FIG. 2 is a schematic cross-sectional view of an adhesive sheet according to another preferred embodiment of the present invention. The adhesive sheet 200 further includes a base material 30 on the opposite side of the tether layer 20 from the adhesive layer 10. In addition, although not shown, any appropriate other adhesive layer or adhesive layer may be provided on the side of the substrate 30 opposite to the mooring layer 20. Moreover, a release paper may be arrange | positioned on the outer side of the base material 30 until the adhesive sheet of this invention is put into practical use. When a release paper is arranged on the outer side of the base material 30, the release paper can be attached to the base material through any suitable adhesive. In FIG. 2, the form in which the adhesive layer 10 and the mooring layer 20 are formed on one side of the substrate 30 is shown. The adhesive layer 10 and the mooring layer 20 may also be formed on both sides of the substrate 30, such as adhesion. Composition of agent layer / tethering layer / base material / tethering layer / adhesive layer.

B. Tethered layer

The elastic modulus of the tethered layer measured by the nanoindentation method at 25 ° C is preferably 1 MPa or more, more preferably 1 MPa to 5000 MPa, still more preferably 1 MPa to 3500 MPa, and even more preferably 1 MPa to 1000 MPa. It is preferably 10 MPa to 600 MPa. An adhesive sheet having a layer exhibiting such an elastic modulus can be obtained, for example, by forming a captive layer formed of a material different from the adhesive layer. The so-called elastic modulus measured by the nano-indentation method refers to the continuous measurement of the load weight and indentation depth applied to the indenter when the indenter is pressed into the sample (for example, the adhesive surface) at the time of loading and unloading. The modulus of elasticity obtained from the obtained load weight-pressing depth curve. In this specification, the so-called elastic modulus measured by the nanoindentation method means that the measurement conditions are set to load: 1mN, load, unloading speed: 0.1mN / s, and retention time: 1s. The resulting modulus of elasticity.

As described above, by providing a captive layer having an elastic modulus of 1 MPa or more as measured by the nano-indentation method, it is possible to provide a sheet for temporary fixation at the time of cutting and processing of electronic parts and the like, and contribute to this. Adhesive sheet for better cutting accuracy. Furthermore, by setting the elastic modulus of the tethered layer measured by the nanoindentation method to 5000 MPa or less, the tethered layer can conform to the unevenness of the thermally expandable microspheres protruding from the adhesive layer, and can be buried. Into the form of the thermally expandable microspheres, the thermally expandable microspheres are covered. In addition, it is possible to provide an adhesive sheet that contributes to achieving excellent cutting accuracy without impairing the flexibility required for the entire adhesive sheet (for example, a degree of flexibility capable of matching the adherend).

The tensile elastic modulus of the tethered layer at 25 ° C is preferably 1 MPa or more, more preferably 1 MPa to 5000 MPa, and even more preferably 1 MPa to 1000 MPa. Within this range, the same effects as described above can be obtained with respect to the elastic modulus measured by the nanoindentation method. The tensile elastic modulus can be measured in accordance with JIS K 7161: 2008.

The flexural modulus of the tethered layer at 25 ° C is preferably 1 MPa or more, more preferably 1 MPa to 5000 MPa, and even more preferably 1 MPa to 1000 MPa. Within this range, the same effects as described above can be obtained with respect to the elastic modulus measured by the nanoindentation method. The bending elastic modulus can be measured in accordance with JIS K 7171: 2008.

The thickness of the mooring layer can be set to any appropriate value according to the unevenness (the height of the protruding portion) of the thermally expandable microspheres protruding from the adhesive layer. The thickness of the tethering layer is preferably the thickness of the thermally expandable microspheres that can completely cover the protruding from the adhesive layer, for example, it is thicker than 0.4 μm and less than 200 μm, preferably 0.6 μm to 100 μm, more preferably 0.6 μm to 45 μm. Furthermore, in this specification, the thickness of the tethered layer, as shown in FIG. 1, refers to the interface between the material constituting the tethered layer 20 and the adhesive 12 constituting the adhesive layer 10 and the interface between the tethered layer and the interface. The distance to the opposite side. That is, a part of the thermally expandable microspheres 11 protruding from the adhesive layer 10 is not an evaluation target for the thickness of the tethered layer. When the adhesive sheet is cut and the cut surface is visually observed, when the interface between the material constituting the tether layer 20 and the adhesive 12 constituting the adhesive layer 10 is clear, the thickness of the tether layer may be a ruler, a vernier caliper, or a micrometer. Perform the measurement. The thickness of the tethered layer can also be measured using a microscope such as an electron microscope, an optical microscope, or an atomic force microscope. Furthermore, the interface can be discriminated and the thickness of the tethered layer can be measured based on the difference in the composition of the tethered layer and the adhesive layer. For example, spectral analysis such as Raman spectroscopy, infrared spectroscopy, and X-ray electron spectroscopy can be used; MALDI-TOFMS (Matrix-Assisted Laser Desorption Ionization-time of Flight Mass) Spectrometer) or TOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometer), etc., to analyze the composition of the materials constituting the tether layer and the adhesive constituting the adhesive layer. Based on the difference in the composition, the interface is discriminated and the thickness of the tethered layer is measured. As described above, the method of distinguishing the interface by spectral analysis or mass analysis is useful in the case where it is difficult to distinguish the interface when observing with visual observation or a microscope.

Examples of the material constituting the mooring layer include a silicone polymer, an epoxy polymer, a polycarbonate polymer, an ethylene polymer, an acrylic polymer, and a urethane polymer. Polymers, polymers such as polyesters (e.g., polyethylene terephthalate), polyolefin polymers, polyamide polymers, polyimide polymers, unsaturated hydrocarbon polymers, etc. material. If these polymer materials are used, monomer species can be appropriately selected Type, crosslinking agent, degree of polymerization, etc., to easily form a tethered layer having the above-mentioned elastic modulus. The polymer material is excellent in affinity with the heat-expandable microspheres, the adhesive constituting the adhesive layer, and the substrate. These polymer materials may be used alone or in combination of two or more.

As the material constituting the mooring layer, a resin material that can be hardened (high elastic modulus) by irradiation with active energy rays can be used. If a tethered layer is formed from such a material, the following adhesive sheet can be obtained: low elasticity, high flexibility, and excellent operability when attaching an adhesive sheet, and can be irradiated with active energy rays after attaching And adjusted to the elastic modulus of the above range. Examples of the active energy rays include gamma rays, ultraviolet rays, visible light, infrared rays (hot rays), radio frequency waves, alpha rays, beta rays, electron beams, plasma flow, free rays, and particle beams. The tethered layer containing a resin material that can be hardened by irradiation with active energy rays is preferably the above-mentioned elastic modulus measured by the nanoindentation method after irradiation with active energy rays. The tethered layer containing a resin material that can be hardened by irradiation with active energy rays is preferably such that the above-mentioned tensile elastic modulus and / or flexural elastic modulus after irradiation with active energy rays fall within the above range.

Examples of resin materials that can be cured (highly elastic modulus) by irradiating active energy rays include, for example, ultraviolet curing systems (Kato Kiyo, issued by the Comprehensive Technology Center, (1989)), and light curing technology (Technical Information) Association (2000)), Japanese Patent Laid-Open No. 2003-292916, Japanese Patent No. 4151850, and other resin materials. More specifically, a resin material (R1) containing a polymer serving as a mother agent and an active energy ray reactive compound (monomer or oligomer), and a resin material (R2) containing an active energy ray reactive polymer may be mentioned. Wait.

Examples of the polymer used as the mother agent include natural rubber, polyisobutylene rubber, styrene-butadiene rubber, styrene-isoprene-styrene block copolymer rubber, recycled rubber, and butyl rubber. , Polyisobutylene rubber, nitrile rubber (NBR) and other rubber-based polymers; silicone polymers; acrylic polymers. These polymers can be used alone or in groups Use 2 or more types together.

Examples of the active energy ray-reactive compound include photoreactive monomers having a functional group having a carbon-carbon multiple bond, such as acrylfluorenyl, methacrylfluorenyl, vinyl, allyl, and ethynyl. Or oligomers. Specific examples of the photoreactive monomer or oligomer include trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, and pentaerythritol tri (methyl) ) Acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, etc. (meth) acrylfluorenyl-containing compounds; the (meth) acrylfluorenyl-containing compounds Dimer to pentamer.

In addition, as the active energy ray reactive compound, monomers such as epoxidized butadiene, glycidyl methacrylate, acrylamide, and vinylsiloxane; or oligomers containing the monomers can also be used. The resin material (R1) containing these compounds can be hardened by high energy rays such as ultraviolet rays and electron beams.

Further, 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 heterocycles in the molecule may be used. The mixture is irradiated with active energy rays (eg, ultraviolet rays, electron beams), and the organic salt is cleaved to generate ions, which become the starting species and cause a ring-opening reaction of the heterocyclic ring to form a three-dimensional network structure. Examples of the organic salts include phosphonium salts, phosphonium salts, ammonium salts, phosphonium salts, and borate salts. Examples of the heterocyclic ring in the compound having a plurality of heterocyclic rings in the molecule include oxepane, oxetane, oxetane, thiocyclopropane, and aziridine.

In the resin material (R1) containing the polymer serving as the mother agent and the active energy ray reactive compound, the content ratio of the active energy ray reactive compound is preferably 0.1 part by weight relative to 100 parts by weight of the polymer serving as the mother agent. Parts to 500 parts by weight, more preferably 1 part to 300 parts by weight, and still more preferably 10 parts to 200 parts by weight.

Resin containing polymer as active ingredient and active energy ray reactive compound The material (R1) may contain any suitable additives as required. Examples of the additives include an active energy ray polymerization initiator, an active energy ray polymerization accelerator, a crosslinking agent, a plasticizer, and a vulcanizing agent. As the active energy ray polymerization initiator, any appropriate initiator can be used according to the kind of active energy ray used. The active energy ray polymerization initiator may be used alone or in combination of two or more. In the resin material (R1) containing the polymer serving as the mother agent and the active energy ray reactive compound, the content ratio of the active energy ray polymerization initiator relative to 100 parts by weight of the polymer serving as the mother agent, preferably 0.1 weight Parts to 10 parts by weight, more preferably 1 to 5 parts by weight.

Examples of the active energy ray-reactive polymer include polymers having a functional group having a carbon-carbon multiple bond, such as acrylfluorenyl, methacrylfluorenyl, vinyl, allyl, and ethynyl. Specific examples of the polymer containing an active energy ray-reactive functional group include a polymer containing a polyfunctional (meth) acrylate, a photocationic polymer, and a cinnamyl group containing a polyvinyl cinnamate. Polymers; diazotized amine phenolic resins; polypropylene amines, etc. As the resin material (R2) containing an active energy ray reactive polymer, a mixture of an allyl-containing active energy ray reactive polymer and a thiol group-containing compound may be used. In addition, as long as a precursor of a tether layer having a practical hardness (viscosity) can be formed before hardening by active energy ray irradiation (for example, when attaching an adhesive sheet), the active energy ray reaction is included in addition In addition to the polymer having a functional group, an oligomer containing an active energy ray-reactive functional group may be used.

The resin material (R2) containing the active energy ray reactive polymer may further contain the active energy ray reactive compound (monomer or oligomer). The resin material (R2) containing the active energy ray-reactive polymer described above may contain any appropriate additives as necessary. Specific examples of the additives are the same as the additives that can be contained in the resin material (R1) containing the polymer serving as the mother agent and the active energy ray-reactive compound. In the resin material (R2) containing the active energy ray reactive polymer, the content ratio of the active energy ray polymerization initiator is 100 parts by weight with respect to the active energy ray reactive polymer, and preferably 0.1 to 10 parts by weight , Better It is 1 to 5 parts by weight.

The mooring layer may further contain beads. Examples of the beads include glass beads and resin beads. If such beads are added to the mooring layer, an adhesive sheet can be obtained which can improve the elastic modulus of the mooring layer and can process the object more accurately. The average particle diameter of the beads is, for example, 0.01 μm to 50 μm. The added amount of the beads is, for example, 10 to 200 parts by weight, and preferably 20 to 100 parts by weight with respect to 100 parts by weight of the entire tethered layer.

C. Adhesive layer

The adhesive layer preferably contains an adhesive and thermally expandable microspheres.

The thickness of the adhesive layer is preferably 20 μm or less, more preferably 0.1 μm to 20 μm, still more preferably 1 μm to 15 μm, and even more preferably 1 μm to 10 μm. When the thickness of the adhesive layer is more than 20 μm, when it is used as a temporary fixing sheet when cutting electronic parts, the following abnormalities may occur: the wafer after cutting is reattached; cutting The cross section becomes unstable; wafer defects occur during cutting; chippings, etc. occur. In the present invention, by providing a tethering layer, the thermally expandable microspheres are allowed to protrude from the adhesive layer, and the adhesive layer can be made thin. On the other hand, when the thickness of the adhesive layer is less than 0.1 μm, sufficient adhesive force may not be obtained. Furthermore, in this specification, the thickness of the adhesive layer refers to the interface between the material constituting the tether layer 20 and the adhesive 12 constituting the adhesive layer 10 to the interface between the adhesive layer and the interface as shown in FIG. 1. The distance to the opposite side. That is, a part of the thermally expandable microspheres 11 protruding from the adhesive layer 10 is not an evaluation target of the thickness of the adhesive layer. Furthermore, the method of distinguishing the interface between the material constituting the tethered layer 20 and the adhesive 12 constituting the adhesive layer 10 is as described in the above item B.

The adhesive layer preferably contains thermally expandable microspheres having a particle diameter larger than the thickness of the adhesive layer. In other words, the thickness of the adhesive layer may be smaller than the particle diameter of the thermally expandable microspheres. In the present invention, since the adhesive layer can be made thin, it is possible to obtain an adhesive sheet that is useful as a temporary fixing sheet when cutting an electronic component or the like and contributes to excellent cutting accuracy.

The elastic modulus of the above-mentioned adhesive layer at the temperature when the adhesive sheet of the present invention is measured by the nanoindentation method is preferably less than 100 MPa, more preferably 0.1 MPa to 50 MPa, and even more preferably 0.1MPa ~ 10MPa. The so-called elastic modulus of the adhesive layer measured by the nano-indentation method refers to the elastic modulus measured by the measurement method described in item B above, which is the portion where no thermally expandable microspheres are selected, that is, the adhesive Modulus of elasticity. The temperature when the above-mentioned adhesive sheet is attached is, for example, 10 ° C. to 80 ° C. when an acrylic adhesive is used as the adhesive, and when a styrene-diene block copolymer-based adhesive is used as the adhesive. At 40 ℃ ~ 120 ℃.

(Adhesive)

The adhesive is preferably one that does not restrict the expansion or foaming of the thermally expandable microspheres during heating. Examples of the adhesive include an acrylic adhesive, a rubber adhesive, a vinyl alkyl ether adhesive, a silicone adhesive, a polyester adhesive, a polyamide adhesive, and an amine group. Improved creep properties of formate-based adhesives, styrene-diene block copolymer-based adhesives, radiation-hardening adhesives, and hot-melt resins with a melting point of about 200 ° C or less in these adhesives Type adhesive and the like (for example, refer to Japanese Patent Laid-Open No. 56-61468, Japanese Patent Laid-Open No. 63-17981, and the like). Among these, an acrylic adhesive or a rubber adhesive is preferable. In addition, the said adhesive can be used individually or in combination of 2 or more types.

Examples of the acrylic adhesive include an acrylic polymer (homopolymer or copolymer) using one or more alkyl (meth) acrylates as a monomer component as a base polymer. Acrylic adhesives. Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and (methyl) Base) butyl acrylate, isobutyl (meth) acrylate, second butyl (meth) acrylate, third butyl (meth) acrylate, amyl (meth) acrylate, hexyl (meth) acrylate , Heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, (meth) C Isononyl enoate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, (meth) acrylic acid Tridecyl ester, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, cetyl (meth) acrylate, heptadecyl (meth) acrylate, C1-20 alkyl (meth) acrylates, such as octadecyl (meth) acrylate, undecyl (meth) acrylate, and eicosyl (meth) acrylate. Among them, an alkyl (meth) acrylate having a linear or branched alkyl group having 4 to 18 carbon atoms can be preferably used.

For the purpose of improving the cohesive force, heat resistance, and cross-linking properties, the acrylic polymer may contain units corresponding to other monomer components that can be copolymerized with the alkyl (meth) acrylate, as necessary. Examples of such monomer components include carboxyl-containing compounds such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and butenoic acid. Monomers; anhydride monomers such as maleic anhydride, itaconic anhydride; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxy (meth) acrylate Hexyl ester, hydroxyoctyl (meth) acrylate, hydroxydecyl (meth) acrylate, hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl methacrylate and other monomers containing hydroxyl groups ; Styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, (meth) acrylamidopropanesulfonic acid, sulfopropyl (meth) acrylate, (Meth) acrylic acid oxynaphthalenesulfonic acid and other monomers containing sulfonic acid groups; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (methyl) ) (N-substituted) fluorenamine monomers such as acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide; (meth) acrylamine Ethyl ester, (meth) acrylic N, N-di (Aminoalkyl (meth) acrylate-based monomers such as aminoethyl ester and third butylaminoethyl (meth) acrylate; methoxyethyl (meth) acrylate, ethyl (meth) acrylate) (Meth) acrylic alkoxyalkyl ester-based monomers; N-cyclohexylcis-butenedifluoreneimide, N-isopropylcisbutenedifluoreneimine, N-laurylcis Butene difluorene imide monomers such as butene difluorene imine, N-phenylcis butylene diimide; N-methyl Ikonimine, N-ethyl Ikonimine, N-butyl Ikonimide, N-octyl Ikonimide, N-2-Ethylhexyl Ikonimide, N-Cyclohexyl Ikonimide, N-Lauryl Ikonimide Ikon 醯 imine-based monomers such as imine; N- (meth) acryloxymethylene succinimide, N- (meth) acryl 醯 -6-oxyhexamethylene succinimide Succinimide-based monomers such as imine, N- (meth) acrylfluorenyl-8-oxyoctamethylene succinimide; vinyl acetate, vinyl propionate, N-vinylpyrrolidone , Methyl vinyl pyrrolidone, vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piperidine Vinylpyridine , Vinylpyrrole, vinylimidazole, vinyl Vinyl monomers such as azole, vinylmorpholine, N-vinylcarboxamides, styrene, α-methylstyrene, N-vinyl caprolactam; cyano groups such as acrylonitrile, methacrylonitrile Acrylate monomer; epoxy-containing acrylic monomers such as glycidyl (meth) acrylate; polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, methoxyethylene glycol (Meth) acrylates, diol acrylic acrylate monomers such as methoxy polypropylene glycol (meth) acrylate; tetrahydrofurfuryl (meth) acrylate, fluorine-containing (meth) acrylate, polysiloxane ( Acrylic monomers having heterocyclic rings, halogen atoms, silicon atoms, etc. such as meth) acrylates; hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly ) Propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) Multifunctional monomers such as acrylate, dipentaerythritol hexa (meth) acrylate, epoxy acrylate, polyester acrylate, and urethane acrylate ; Olefin monomers, such as isoprene, butadiene, isobutylene; vinyl ether monomers, such as vinyl ether. These monomer components can be used alone or in combination of two or more.

Examples of the rubber-based adhesive include rubber-based adhesives based on the following polymers: natural rubber; polyisoprene rubber, styrene-butadiene (SB) rubber, and styrene-isoprene (SI) rubber, styrene-isoprene-styrene block copolymer (SIS) rubber, styrene-butadiene-styrene block copolymer (SBS) rubber, styrene-ethylene-butene -Styrene block copolymer (SEBS) rubber, styrene-ethylene-propylene-styrene block copolymer (SEPS) rubber, styrene-ethylene-propylene block copolymer (SEP) rubber, recycled rubber, Synthetic rubbers such as butyl rubber, polyisobutylene, and modified products thereof.

The above-mentioned adhesive may contain any appropriate additives as needed. Examples of the additive include a crosslinking agent, an adhesion-imparting agent, a plasticizer (for example, a trimellitate-based plasticizer, a pyromellitic-based plasticizer), a pigment, a dye, and a filler. , Anti-aging agent, conductive material, antistatic agent, ultraviolet absorber, light stabilizer, peeling adjuster, softener, surfactant, flame retardant, antioxidant, etc.

As the adhesion-imparting agent, any appropriate adhesion-imparting agent can be used. As the adhesion-imparting agent, for example, an adhesion-imparting resin can be used. Specific examples of the adhesion-imparting resin include rosin-based adhesion-imparting resin (for example, unmodified rosin, modified rosin, rosin phenol-based resin, rosin ester-based resin, etc.), and terpene-based adhesion-imparting resin (for example, terpene Ethylene resins, terpene-phenol resins, styrene-modified terpene resins, aromatic modified terpene resins, hydrogenated terpene resins, hydrocarbon-based adhesion-imparting resins (for example, aliphatic hydrocarbon resins, Aliphatic cyclic hydrocarbon resin, aromatic hydrocarbon resin (for example, styrene resin, xylene resin, etc.), aliphatic-aromatic petroleum resin, aliphatic-alicyclic petroleum resin, hydrogenated hydrocarbon resin , Lavender resin, lavender resin, etc.), phenol-based adhesion-imparting resin (for example, alkanol-based resin, xylene formaldehyde-based resin, soluble phenolic resin, phenolic resin, etc.) Polyamine-based adhesion-imparting resin, epoxy-based adhesion-imparting resin, elastic system adhesion-imparting resin, and the like. Among them, a rosin-based adhesion-imparting resin, a terpene-based adhesion-imparting resin, or a hydrocarbon-based adhesion-imparting resin (such as a styrene-based resin) is preferred. The adhesion-imparting agent can be used alone or in combination of two or more.

A commercial item can also be used for the said adhesion-imparting agent. Specific examples of the adhesion-imparting agent commercially available include terpene-phenols such as trade names "YS Polystar S145", "Mighty Ace K140" manufactured by Yasuhara Chemical, and "Tamanol 901" manufactured by Arakawa Chemical. Resins; rosin phenol resins such as "Sumilite Resin PR-12603" manufactured by Sumitomo Bakelite; "Tamanol 361" manufactured by Arakawa Chemical; and "Tamanol 1010R" and "Tamanol" manufactured by Arakawa Chemical "200N" and other alkanol-based resins; alicyclic saturated hydrocarbon resins such as "Arkon P-140" manufactured by Arakawa Chemical Company.

The added amount of the adhesion-imparting agent is preferably 5 to 100 parts by weight, and more preferably 10 to 50 parts by weight, based on 100 parts by weight of the base polymer.

Examples of the crosslinking agent include, in addition to isocyanate-based crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, and peroxide-based crosslinking agents, urea-based crosslinking agents and metal alkoxide-based crosslinking agents. Crosslinking agent, metal chelate crosslinking agent, metal salt crosslinking agent, carbodiimide crosslinking agent, An oxazoline-based crosslinking agent, an aziridine-based crosslinking agent, an amine-based crosslinking agent, and the like. Among these, an isocyanate-based crosslinking agent or an epoxy-based crosslinking agent is preferred.

Specific examples of the isocyanate-based crosslinking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; cyclopentyl diisocyanate, cyclohexyl diisocyanate, and isophorone. Cycloaliphatic isocyanates such as diisocyanate; aromatic isocyanates such as 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate; trimethylolpropane / toluene diisocyanate Terpolymer adduct (manufactured by Japan Polyurethane Industry Corporation, trade name "Coronate L"), trimethylolpropane / hexamethylene diisocyanate terpolymer adduct (manufactured by Japan Polyurethane Industry Corporation, trade name "Coronate L" HL "), isocyanurate bodies of hexamethylene diisocyanate (manufactured by Japan Polyurethane Industry Co., Ltd., trade name" Coronate HX "), and the like. The content of the isocyanate-based cross-linking agent can be set to any suitable amount according to the required adhesive force. The representative amount is 0.1 to 20 parts by weight, and more preferably 0.5 to 100 parts by weight of the base polymer. Parts ~ 10 parts by weight.

Examples of the epoxy-based crosslinking agent include N, N, N ', N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, and 1,3-bis (N, N- Glycidylaminomethyl) cyclohexane (manufactured by Mitsubishi Gas Chemical Company, trade name "Tetrad C"), 1,6-hexanediol diglycidyl ether (manufactured by Kyoeisha Chemical Company, trade name "Epolight 1600" "), Neopentyl glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name" Epolight 1500 " NP "), ethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name" Epolight 40E "), propylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name" Epolight 70P "), polyethylene Glycol diglycidyl ether (manufactured by Nippon Oil & Fats Co., Ltd. under the trade name "Epiol E-400"), polypropylene glycol diglycidyl ether (manufactured by Nippon Oil & Fats Co., Ltd. under the trade name "Epiol P-200"), sorbitol polyglycidyl ether Ether (manufactured by Nagase chemteX, trade name "Denacol EX-611"), glycerol polyglycidyl ether (manufactured by Nagase chemteX, trade name "Denacol EX-314"), pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether (Manufactured by Nagase chemteX, trade name "Denacol EX-512"), sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, diglycidyl phthalate Ester, triglycidyl-tris (2-hydroxyethyl) isocyanurate, resorcinol diglycidyl ether, bisphenol S-diglycidyl ether, a ring with two or more epoxy groups in the molecule Oxygen-based resins. The content of the epoxy-based cross-linking agent can be set to any suitable amount according to the required adhesive force. The representative amount is 0.01 to 10 parts by weight, and more preferably 0.03 to 100 parts by weight of the base polymer. Part by weight to 5 parts by weight.

(Thermally expandable microspheres)

As the thermally expandable microspheres, any suitable thermally expandable microspheres can be used as long as they are microspheres that can be expanded or expanded by heating. As the thermally expandable microspheres, for example, microspheres formed by encapsulating a substance that is easily expanded by heating in a shell having elasticity can be used. Such thermally expandable microspheres can be produced by any suitable method, such as a coacervation method and an interfacial polymerization method.

Examples of substances that can be easily expanded by heating include propane, propylene, butene, n-butane, isobutane, isopentane, neopentane, n-pentane, n-hexane, isohexane, heptane, Low boiling point liquids such as octane, petroleum ether, halides of methane, and tetraalkylsilane; azodimethoxamine gasified by thermal decomposition.

Examples of the substance constituting the shell include polymers including acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethoxyacrylonitrile, and butadienenitrile; acrylic acid; , Methacrylic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid and other carboxylic acid monomers; vinylidene chloride; vinyl acetate; methyl (meth) acrylate, (meth) ) Ethyl acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, isopropyl (meth) acrylate (Meth) acrylates such as esters, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, and β-carboxyethyl acrylate; styrene monomers such as styrene, α-methylstyrene, and chlorostyrene Body; acrylamide monomers such as acrylamide, substituted acrylamide, methacrylamide, and substituted methacrylamide. The polymer containing 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, and methyl methacrylate-acrylonitrile copolymer Compounds, acrylonitrile-methacrylonitrile-Iconic acid copolymers, 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 bicarbonate, sodium bicarbonate, ammonium nitrite, sodium borohydride, and various azides. Examples of the organic foaming agent include chlorofluoroalkane compounds such as trichloromonofluoromethane and dichloromonofluoromethane; azobisisobutyronitrile, azodimethylformamide, and azodicarboxylic acid. Azo compounds such as barium; p-toluenesulfonylhydrazine, diphenylhydrazone-3,3'-disulfazinium, 4,4'-oxobis (benzenesulfonylhydrazine), allylbis (sulfonylhydrazine) Isohydrazine-based compounds; p-toluenesulfonamide urea, 4,4'-oxybis (benzenesulfonamide) and other amine urea-based compounds; 5-morpholinyl-1,2,3,4-thiatriazole, etc. Triazole compounds; N, N'-dinitrosopentamethylenetetramine, N, N'-dimethyl-N, N'-dinitroso-p-xylylenediamine and other N-nitroso Base compounds.

As the thermally expandable microspheres, a commercially available product may be used. Specific examples of commercially available thermally expandable microspheres include the product name "Matsumoto Microsphere" (grades: F-30, F-30D, F-36D, F-36LV, F-50) manufactured by Matsumoto Oil & Fats Pharmaceutical Co., Ltd. , F-50D, F-65, F-65D, FN-100SS, FN-100SSD, FN-180SS, FN-180SSD, F-190D, F-260D, F-2800D), trade names made by Nippon Fillite Expancel "(grades: 053-40, 031-40, 920-40, 909-80, 930-120), Wu Yu Chemical Industry Company Manufacturing of "Daifoam" (grades: H750, H850, H1100, S2320D, S2640D, M330, M430, M520), Sekisui Chemical Industry Co., Ltd. manufacturing of "Advancell" (grade: EML101, EMH204, EHM301, EHM302, EHM303, EM304, EHM401, EM403 , EM501), etc.

The particle diameter of the thermally expandable microspheres before heating is preferably 0.5 μm to 80 μm, more preferably 5 μm to 45 μm, still more preferably 10 μm to 20 μm, and even more preferably 10 μm to 15 μm. Therefore, the particle size of the thermally expandable microspheres before heating is preferably 6 μm to 45 μm, and more preferably 15 μm to 35 μm. The particle diameter and the average particle diameter are values obtained by a particle size distribution measurement method in a laser scattering method.

The thermally expandable microspheres preferably have a moderate strength with a volume expansion ratio of preferably 5 times or more, more preferably 7 times or more, and even more preferably 10 times or more without breaking. When such a thermally expandable microsphere is used, the adhesive force can be efficiently reduced by heat treatment.

The content ratio of the thermally expandable microspheres in the above-mentioned adhesive layer can be appropriately set according to the required reduction of the adhesive force and the like. The content ratio of the thermally expandable microspheres is 100 parts by weight with respect to the base polymer forming the adhesive layer, for example, 1 to 150 parts by weight, preferably 10 to 130 parts by weight, and more preferably 25 parts by weight to 100 parts by weight.

D. Substrate

Examples of the substrate include a resin sheet, a non-woven fabric, paper, a metal foil, a woven fabric, a rubber sheet, a foamed sheet, a laminated body (particularly a laminated body containing a resin sheet), and the like. Examples of the resin constituting the resin sheet include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), and polyethylene ( PE), polypropylene (PP), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), polyamide (nylon), fully aromatic polyamide (aromatic polyamide), polyamide Amine (PI), polyvinyl chloride (PVC), polyphenylene sulfide (PPS), fluorine resin, polyetheretherketone (PEEK), etc. Examples of non-woven fabrics include non-woven fabrics made of natural fibers having heat resistance such as non-woven fabrics containing manila hemp; non-woven fabrics made of polypropylene resin, non-woven fabrics made of polyethylene resin, and ester-based resins. Non-woven fabrics such as synthetic resin.

The thickness of the substrate can be set to any appropriate thickness according to the required strength or flexibility, the purpose of use, and the like. The thickness of the substrate is preferably 1000 μm or less, more preferably 1 μm to 1000 μm, still more preferably 1 μm to 500 μm, even more preferably 3 μm to 300 μm, and most preferably 5 μm to 250 μm.

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 electric shock exposure, ionizing radiation treatment, and coating treatment using a primer. Such surface treatment can improve the adhesion between the mooring layer and the substrate. In particular, a coating treatment using an organic coating material is preferred because it can improve the adhesion and prevent the tethered layer from being easily damaged during heat peeling.

Examples of the organic coating material include those described in Plastic Hard Coating Material II (CMC Publication, (2004)). It is preferable to use a urethane-based polymer, and it is more preferable to use a polyacrylate urethane, a polyester urethane, or a precursor thereof. The reason for this is that the application and coating on the substrate are relatively simple, and a variety of substances can be industrially selected and can be obtained inexpensively. The urethane-based polymer is, for example, a polymer containing a reaction mixture of an isocyanate monomer and an alcoholic hydroxyl-containing monomer (for example, a hydroxyl-containing acrylic compound or a hydroxyl-containing ester compound). The organic coating material may contain a chain extender such as polyamine, an anti-aging agent, an oxidation stabilizer, and the like as any additives. The thickness of the organic coating layer is not particularly limited. For example, the thickness is preferably about 0.1 μm to 10 μm, preferably about 0.1 μm to 5 μm, and more preferably about 0.5 μm to 5 μm.

E. Manufacturing method of adhesive sheet

Examples of the method for producing the adhesive sheet of the present invention include the following methods: (1) The above-mentioned adhesive is applied to a release film (release paper) to form an adhesive coating layer, and the above is applied by pressure or the like. The thermally expandable microspheres are embedded in the adhesive coating layer to form an adhesive layer, and a (laminated) retention layer is formed on the adhesive layer; (2) the release film is coated with the above-mentioned adhesive A composition for forming an adhesive layer with heat-expandable microspheres to form an adhesive coating layer, and form a (laminated) retention layer on the adhesive coating layer; (3) apply the above-mentioned adhesive on a release film After forming the adhesive coating layer, a (laminated) tether layer is formed on the adhesive coating layer, and then the release film is peeled off from the side of the adhesive coating layer opposite to the tether layer (adhesion). The surface) side is embedded with the thermally expandable microspheres by pressure or the like; (4) A retention layer is formed on the release film, the thermally expandable microspheres are provided on one side, and an adhesive agent is applied to the installation surface. . In the methods (1) to (4) above, an adhesive layer can be formed by drying the adhesive coating layer, and the drying can be performed at any appropriate timing. This drying may be performed before embedding the thermally expandable microspheres, or may be performed after embedding. In addition, it may be performed before the captive layer is formed, or it may be performed after the formation. When the heat-expandable microspheres are buried and dried, the heat-expandable microspheres are preferably dried at a temperature at which they are not easily expanded or foamed. The release film may be peeled after the operations shown in (1) and (2) above, or the release film may be retained to protect the adhesive surface until the adhesive sheet is put to practical use.

In the case where the adhesive sheet of the present invention has a substrate, the adhesive sheet can be interposed with any suitable adhesive or adhesive after the operations of (1) to (4) above to adhere to the captive layer. The substrate is attached to the opposite side of the agent layer. Alternatively, a laminated body of the base material and the mooring layer, and a laminated body of the release film and the adhesive layer (or an adhesive coating layer) may be separately prepared, and then these laminated bodies may be bonded together.

Examples of the method for forming the mooring layer include the following: (i) The polymer material or the resin material described in the above item B is thermally melted, and a film-shaped molded body is obtained by extrusion molding, and the molded body is formed. Laminated on the above-mentioned adhesive layer (or adhesive coating layer) or substrate; (ii) applying a resin solution containing the above polymer material or resin material to the above-mentioned adhesive layer (or adhesive coating layer) or The substrate is then dried; (iii) a captive layer-forming composition containing a monomer, oligomer, or macromonomer capable of forming the polymer material or resin material is applied to the adhesive Layer (or an adhesive coating layer) or a substrate, polymerizing the composition for forming a mooring layer (for example, polymerizing by heating, active energy ray irradiation, etc.) and the like. borrow According to the method (iii), the amount of solvent and / or heat energy used can be reduced. Furthermore, in the method (ii), the resin solution may be applied to another release film, and then dried to obtain a film-shaped molded body, and the formed volume layer is then deposited on the adhesive layer. (Or adhesive coating) or on a substrate. In the method (iii), the composition for forming a captive layer may be coated on another release film, and then dried to form a captive layer precursor, and the precursor may be laminated on the aforementioned layer. An adhesive layer (or an adhesive coating layer) or a substrate is then polymerized.

For example, in the method (iii) above, when a captive layer containing an epoxy-based polymer is formed, coating with 2,2- (4-hydroxyphenyl) propane diglycidyl ether, bis A method for heating (for example, 60 ° C. to 120 ° C.) a composition for forming a captive layer of an epoxy compound such as (4-hydroxyphenyl) methane and any suitable curing agent.

For example, in the method (iii) above, when forming a retention layer containing a urethane-based polymer, coating with an isocyanate compound such as toluene diisocyanate, hexamethylene diisocyanate, and poly A method for heating (for example, 60 ° C. to 120 ° C.) a composition for forming a captive layer of a polyol compound such as an ether polyol and a polyester polyol.

For example, in the method (iii) above, when forming a captive layer containing an ethylene-based polymer, a captive layer for forming a captive layer containing an ethylene compound such as vinyl chloride, styrene, and any appropriate initiator may be used. combination.

The said composition for forming a mooring layer may contain additives, such as a starter, a catalyst, a ultraviolet absorber, and an antioxidant, as needed. The beads may also be contained.

In the case where the captive layer includes a resin material that can be hardened by irradiation with active energy rays, the active sheet may be irradiated at any appropriate timing to obtain an adhesive sheet. Irradiation of the active energy ray can be performed, for example, after the adherend (processed object) is attached. Irradiation of active energy rays can also be performed in stages. For example, the adherend may be semi-hardened before being attached, and may be formally hardened after being attached. The type and amount of the active energy ray can be set to any appropriate type and amount according to the type of the resin material constituting the tethered layer.

According to the above manufacturing method, the release film side of the adhesive layer (the side opposite to the mooring layer) The face becomes the sticky face. Since the adhesive surface is formed in a state in contact with the release film, there is no protrusion of the thermally expandable microspheres, and it is flat. On the other hand, on the side of the adhesive layer opposite to the adhesive surface, the thermally expandable microspheres protrude. In the present invention, since the protruding thermally expandable microspheres are covered by the captive layer, both sides of the adhesive sheet are flat, and therefore, the thickness of the adhesive layer can be made thin. Such an adhesive sheet of the present invention is useful as a temporary fixing sheet when cutting electronic parts and the like, and contributes to achieving excellent cutting accuracy and reduction of cutting chips.

F. How to use the adhesive sheet (manufacturing method of electronic parts)

According to another aspect of the present invention, a method for manufacturing an electronic component is provided. The method for manufacturing an electronic component of the present invention includes attaching an electronic component material (substrate) obtained in a large area on the above-mentioned 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, a multilayer capacitor, and a transparent electrode.

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

Thereafter, the electronic component material can be cut by any appropriate method to obtain an electronic component. Examples of the cutting method include a method using a rotary knife and a flat knife, and a method using laser light. In the case where the electronic component material is cut by press cutting using a flat blade, the generation of cutting chips is suppressed, and the yield is improved. In the present invention, since the adhesive layer can be made thin, even if the electronic component material is cut by using a flat knife to cut the material, the following situations can be prevented: the wafer after the cutting is reattached; the cut surface is inclined or It is S-shaped and unstable; wafer defects occur during cutting. Moreover, in the present invention, the above-mentioned effect can be obtained even when cutting with a thin blade, and the manufacturing loss due to the thickness of the blade (loss due to the gap generated between the wafers after cutting) can be reduced. ). In the manufacture of more miniaturized electronic parts, since the number of cut surfaces is large, the present invention, which can reduce manufacturing losses as described above, becomes particularly useful.

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

[Example]

Hereinafter, the present invention will be specifically described by examples, but the present invention is not limited by these examples. The evaluation methods in the examples are as follows. In the examples, unless otherwise specified, "parts" and "%" are based on weight.

(1) Determination of the thickness of the adhesive layer and the tethered layer by Raman images

The adhesive sheets obtained in Examples 1 to 3, 5, 6, and 12 to 15 were sliced with a microtome to prepare measurement samples. For the cross section of the measurement sample, spectroscopic analysis by Raman spectroscopy using alpha300RSA manufactured by WITec, based on the peaks derived from the components added only to the tethered layer (for example, active energy rays in Example 3) The peak intensity of the reactive oligomer (UV1700B) (peak of 1640 cm ^-1 ) was used to measure the thickness of the mooring layer and the adhesive layer. Taking Example 3 as a representative example, the Raman image in this measurement is shown in FIG. 4. The interface 1 is defined as only the surface where the amount of components added to the tethering layer is clearly different. The distance from the interface 1 to the surface of the adhesive layer on the side opposite to the interface 1 is defined as the thickness of the adhesive layer. The distance between the interface 1 and the surface of the tethered layer opposite to the interface is taken as the thickness of the tethered layer.

The measurement conditions for Raman image measurement are as follows.

． Excitation wavelength: 532nm

． Measuring wave number range: 300 ~ 3600cm ^-1

． Grating: 600gr / mm

． Objective lens: × 100

． Measurement time: 0.2sec / 1 spectrum

． Measurement range: 20 × 40μm

． Number of measurements: 100 × 200 points

． Detector: EMCCD (Electron Multiplying Charge Coupled Device, (Electron multiplying charge-coupled element)

(2) Measurement of thickness of adhesive layer and mooring layer by SEM

The adhesive sheet obtained in Examples 4, 7 to 11, 16, 17 and Comparative Example 1 was cut in the thickness direction with a trimming knife, and after performing Pt-Pd sputtering treatment, S3400N made by Hitachi High-Technologies was used. Vacuum scanning electron microscope (SEM) observes the cut surface to identify interface 1. The distance from interface 1 to the side of the adhesive layer opposite to the interface 1 is taken as the thickness of the adhesive layer. The distance of the surface of the retention layer opposite to the interface is taken as the thickness of the captive layer. Taking Example 11 as a representative example, a SEM image of a cross section of the adhesive sheet is shown in FIG. 5.

The measurement conditions for SEM observation are as follows.

． Observation image: ESED (Environmental Secondary Electron Detector) image

． Accelerating voltage: 10kV

． Magnification: 600 times

(3) Measurement of protruding height (H) of thermally expandable microspheres

In Examples 1 to 3, 5, 6, and 12 to 15, the same method as in the above (1) was used, and in Examples 4, 7 to 11, 16, 17, and Comparative Example 1 to the above (2) In the same method, the interface between the adhesive layer and the mooring layer (that is, the interface including the protruding surface of the protruding thermally expandable microspheres) is identified, and the height of the protruding portion of the thermally expandable microspheres from the adhesive layer is measured.

(4) Measurement of the length of the interface between the adhesive layer and the mooring layer (11) and the length (L) of the projection line in the thickness direction of the interface

In Examples 1 to 3, 5, 6, and 12 to 15, the same method as in the above (1) was used, and in Examples 4, 7 to 11, 16, 17, and Comparative Example 1 to the above (2) In the same way, the interface between the adhesive layer and the captive layer (that is, the interface containing the protruding surface of the protruding thermally expandable microspheres) is identified, and the length of the interface between the adhesive layer and the captive layer (l1) and the interface Length (L) of the projection line in the thickness direction. Table 1 shows the ratio (l1 / L) of l1 to L.

(5) Determination of elastic modulus

The adhesive sheets obtained in the examples and comparative examples were cut in the thickness direction with a microtome, and the elastic modulus was measured with a nano indenter for the cut surface.

More specifically, as the mooring layer, the surface of the mooring layer (the surface opposite to the adhesive surface) that is substantially perpendicular to the cut surface, and the surface of the cut surface about 3 μm from the surface are taken as the measurement targets. The software (triboscan) attached to the measurement device is used to numerically process the displacement-load hysteresis curve obtained by pressing the probe (indenter) against the measurement object, thereby obtaining the elastic modulus. In addition, Table 1 shows the modulus of elasticity (average of three measurements) measured on the surface of the cut surface about 3 μm from the surface.

The nanoindentation device and measurement conditions are as follows.

Device and measurement conditions

． Device: Nano indenter; Triboindenter manufactured by Hysitron Inc

． Measurement method: single indentation method

． Measurement temperature: 25 ° C

． Pressing speed: about 1000nm / sec

． Pressing depth: about 800nm

． Probe: Diamond, Berkovich (triangular cone)

(6) Determination of adhesion

(Adhesion before heating (before expanding thermally expandable microspheres))

The adhesive sheets obtained in the examples and comparative examples were cut into a size of width: 20 mm and length: 140 mm. According to JIS Z 0237: 2009, a polyethylene terephthalate film (commercial product) was used as an adherend. Named "Lumirror S-10", manufactured by Toray Co., Ltd .; thickness: 25 μm, width: 30 mm) With a length of 5 mm left and right in the width direction, a 2 kg roller is reciprocated once to attach it to the adhesive surface. Thus, a measurement sample is prepared. This measurement sample was set on a tensile tester (trade name "Shimadzu Autograph AG-120kN" manufactured by Shimadzu Corporation) with a constant temperature bath, and left for 30 minutes. Thereafter, at the peeling angle: 180 °, the peeling speed Degree (tensile speed): Under the condition of 300 mm / min, measure the load when the adherend is peeled from the adhesive sheet in the longitudinal direction, and find the maximum load at this time (the maximum load other than the peak of the initial measurement) Value), and the value obtained by dividing the maximum load by the width of the adhesive tape was taken as the adhesive force (N / 20mm width). In addition, the above operation was performed under the environment of temperature: 23 ± 3 ° C and humidity: 65 ± 5% RH.

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

A measurement sample is prepared in the same manner as described above, and the measurement sample is put into a hot air dryer. After being allowed to stand for 1 minute at the maximum expansion temperature (described below) of the thermally expandable microspheres in a hot-air dryer, the adherend was peeled in the same manner as described above, and the adhesive force was measured. In addition, the operation before and after the hot air dryer was put in was performed under the environment of temperature: 23 ± 3 ° C and humidity: 65 ± 5% RH.

(7) Surface roughness measurement

Regarding the adhesive sheets obtained in the examples and comparative examples, the thermally expandable microspheres were expanded or foamed, and then the surface roughness Ra of the adhesive surface was measured. The expansion or foaming of the heat-expandable microspheres is performed in a hot-air dryer, and allowed to stand at the maximum expansion temperature (described below) of the heat-expandable microspheres for 1 minute. The surface roughness was measured using a laser microscope "OLS4000" manufactured by Olympus.

(8) Separation evaluation of small pieces after cutting

A laminated ceramic sheet of 40 mm × 50 mm (thickness: 500 μm) was bonded to the adhesive sheets obtained in the examples and comparative examples. A cutting device "G-CUT8AA" manufactured by UHT Corporation was used to cut the laminated ceramic sheet on the adhesive sheet into small pieces of 1 mm x 0.5 mm. The laminated ceramic sheet on the adhesive sheet was set along the side of a cylinder having a diameter of 30 mm. In a state of being installed on a cylinder, heat treatment is performed at a specific temperature (the maximum expansion temperature of the thermally expandable microspheres (described below)) to expand the thermally expandable microspheres, thereby peeling the small piece from the adhesive sheet and cutting it in half. The number of unseparated wafers between wafers at the break position is counted. Divide the number of unseparated wafers by the number of 100% fully separated wafers as It is an indicator of separation. When the index is less than 2%, it is set to ◎, when the index is more than 2% and less than 5%, it is set to ￮, when the index is more than 5% and less than 15%, it is set to △, when the index is more than 15% Set to ×.

The details of the composition of the laminated ceramic sheet and the cutting conditions of the cutting device 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 diglyceryl stearate were added to the toluene solvent, and the mixture was carried out using a ball mill disperser. Mixing and dispersing to obtain a toluene solution of the dielectric. This solution was applied to a polyethylene terephthalate film (manufactured by Mitsubishi Polyester Film Co., Ltd., under the trade name "MRF38") with a silicone applicator so that the thickness of the solvent was 50 μm using an applicator. (Thickness: 38 μm) The treated surface of the polysiloxane release agent is dried to obtain a ceramic sheet. A plurality of ceramic sheets were laminated so that the thickness reached 500 μm to obtain a laminated ceramic sheet.

(Cutting conditions)

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

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

(9) Evaluation of cutability of cut surface

In the same manner as in the above (8), the laminated ceramic sheet was cut into small pieces so as to be small pieces of 1 mm × 0.5 mm. 10 pieces were randomly selected from the cut pieces, and the cut surface was observed with a 50-fold magnifying glass to confirm the presence or absence of fragments (fragments of the laminated ceramic sheet produced by the cutting process), and the total number of fragments generated from the 10 pieces The average value is used as an indicator. The case where the index is 0 to 10 places is ◎, the case where it is 10 or more and less than 20 places is ￮, the case is 20 or more and less than 40 places is △, and the case is 40 or more is set to ◎. ×.

The polymer production method is described below. In addition, as long as there is no special explanation here, the portion is Parts by weight.

[Production 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 then heated to obtain a toluene solution of an acrylic copolymer (polymer 1).

[Production Example 2] Preparation of Polymer 2

To toluene, add 30 parts of 2-ethylhexyl acrylate, 70 parts of ethyl acrylate, 4 parts of 2-hydroxyethyl acrylate, 5 parts of N-phenylcis butylene diimide, and use it as a polymerization initiator. After 0.2 parts of benzamidine oxide, heating was performed to obtain a toluene solution of an acrylic copolymer (polymer 2).

[Production Example 3] Preparation of Polymer 3

To toluene were added 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 parts of benzamidine peroxide as a polymerization initiator. Thereafter, heating was performed to obtain a toluene solution of an acrylic copolymer (polymer 3).

[Production 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 benzoamidine peroxide as a polymerization initiator were added to toluene, and then heated to obtain an acrylic system. Copolymer (Polymer 4) in toluene.

[Production 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 parts of benzamidine peroxide as a polymerization initiator were added to ethyl acetate, and then heated to obtain an acrylic copolymer ( Polymer 5) in ethyl acetate.

[Production Example 6] Preparation of Polymer 6

Toluene was added with 50 mol of butyl acrylate, 50 mol of ethyl acrylate, 22 mol of 2-hydroxyethyl acrylate, and benzamidine peroxide as a polymerization initiator (vs. butyl acrylate, ethyl acrylate, and (Total 100 parts of 2-hydroxyethyl acrylate is 0.2 parts), then add Heat to obtain a copolymer solution. To this copolymer solution was added 2-isocyanatoethyl acrylate in an amount equivalent to 80 mol% of the hydroxyl group derived from 2-hydroxyethyl acrylate in the solution, and then heating was performed to the acrylic acid-derived The hydroxy group of 2-hydroxyethyl group is added to 2-isocyanatoethyl methacrylate to obtain a toluene solution of an acrylic copolymer (polymer 6) having a methacrylate group in a side chain.

[Production Example 7] Preparation of Polymer 7

Toluene was added 80 mol of butyl acrylate, 30 mol of acrylofluorenylmorpholine, 20 mol of 2-hydroxyethyl acrylate, and benzamidine peroxide as a polymerization initiator (vs. butyl acrylate, propylene fluorene). A total of 100 parts of morpholine and 2-hydroxyethyl acrylate was 0.2 parts), and then heated to obtain a copolymer solution. To this copolymer solution was added 2-isocyanatoethyl acrylate in an amount corresponding to 50 mol% of the hydroxyl groups derived from 2-hydroxyethyl acrylate in the solution, and then heating was performed to the acrylate-derived acrylic acid. The hydroxy group of 2-hydroxyethyl group is added to 2-isocyanatoethyl methacrylate to obtain a toluene solution of an acrylic copolymer (polymer 7) having a methacrylate group in a side chain.

[Example 1]

(Formation of Adhesive Layer Precursor Layer)

A toluene solution (Polymer 2: 100 parts) of Polymer 2 prepared in Production Example 2; 1 part of an isocyanate-based crosslinking agent (manufactured by Japan Polyurethane Co., Ltd., trade name "Coronate L"); and a terpene as an adhesion-imparting agent -5 parts of phenol resin (manufactured by Sumitomo Bakelite, trade name "Sumilite Resin PR12603") and heat-expandable microspheres (manufactured by Matsumoto Oil & Gas Pharmaceutical Co., Ltd., trade name "Matsumoto Microsphere F-50D", foaming (expansion) onset temperature : 95 ° C. to 105 ° C., maximum expansion temperature: 125 ° C. to 135 ° C., average particle diameter: 10 μm to 18 μm) 40 parts were mixed to prepare a mixed solution. The same solvent (toluene) as the solvent in the mixed solution was further added to the mixed solution, and the viscosity was adjusted to a viscosity for easy application. Using an applicator, the mixed solution was coated on a polyethylene terephthalate film (Mitsubishi Chemical) with a silicone release agent-treated surface so that the thickness of the solvent was 10 μm after the solvent was evaporated (dried). Polyester Film Co., Ltd., trade name "MRF38", thickness: 38 μm), and then dried to form an adhesive layer precursor layer on the polyethylene terephthalate film.

(Formation of the captive layer of the captive layer)

A toluene solution (polymer 1: 100 parts) of the above-mentioned polymer 1 prepared in Production Example 1 and a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate as an active energy ray reactive oligomer (Toa Synthetic Corporation Manufacturing, trade name "Aronix M404") 20 parts, isocyanate-based crosslinking agent (manufactured by Japan Polyurethane Co., trade name "Coronate L") 2 parts, and energy ray polymerization initiator (manufactured by BASF Japan, trade name "Irgacure 651" ") 3 parts were mixed to prepare a mixed solution. The same solvent (toluene) as the solvent in the mixed solution was further added to the mixed solution, and the viscosity was adjusted to a viscosity for easy application. Using an applicator, apply a polyethylene terephthalate film (manufactured by Mitsubishi Chemical Polyester Film, trade name " MRF38 ″, thickness: 38 μm), and then dried to form a captive layer precursor layer on the polyethylene terephthalate film.

(Formation of Adhesive Sheet 1)

The adhesive layer precursor layer and the captive layer precursor layer are bonded together. Next, an ultraviolet irradiation machine "UM810 (high pressure mercury lamp light source)" (manufactured by Nitto Seiki Co., Ltd.) was used to irradiate ultraviolet rays with a cumulative light amount of 300 mJ / cm ² from the drive layer side before the retention layer. After that, the polyethylene terephthalate film with a polysiloxane release agent-treated surface was peeled off to obtain an adhesive sheet 1 (thickness of the adhesive layer: 10 μm, thickness of the tether layer: 25 μm).

[Examples 2 to 15, Comparative Example 1]

The types and blending amounts of polymers, crosslinkers, adhesion-imparting agents, and heat-expandable microspheres when forming the precursor layer of the adhesive layer are set as shown in Table 1. Except for the types and blending amounts of the polymer, the active energy ray reactive oligomer, the crosslinking agent, and the energy ray polymerization initiator, an adhesive sheet was obtained in the same manner as in Example 1.

Furthermore, in Examples 2 to 5, 8, 10, 13 to 15, and Comparative Example 1, when forming a captive layer precursor layer, the mixed solution was applied to a PET film (thickness: 100 μm) instead of being incidentally polymerized. On the polyethylene terephthalate film on the surface of the silicone release agent, the PET film was not peeled off to obtain an adhesive sheet having a PET film (base material). In addition, in Example 4 and Comparative Example 1, an adhesive sheet was obtained without irradiating ultraviolet rays.

The details of the crosslinking agent, adhesion-imparting agent, heat-expandable microspheres, active energy ray reactive oligomer, and energy ray polymerization initiator described in Table 1 are as follows.

<Crosslinking agent>

Tetrad C: manufactured by Mitsubishi Gas Chemical, trade name "Tetrad C", epoxy-based crosslinking agent

<Adhesion imparting agent>

PR51732: "Sumilite Resin PR51732" by Sumitomo Bakelite

S145: "YS Polystar S145" manufactured by Yasuhara Chemical Co., Ltd.

U130: "YS Polystar U130" manufactured by Yasuhara Chemical Co., Ltd.

T160: "YS Polystar T160" manufactured by Yasuhara Chemical Co., Ltd.

<Thermally expandable microspheres>

F-30D: Manufactured by Matsumoto Grease Pharmaceutical Co., Ltd., trade name "Matsumoto Microsphere F-30D", foaming (expansion) starting temperature: 70 ° C to 80 ° C, maximum expansion temperature: 110 ° C to 120 ° C, average particle size 10μm ~ 18μm

F-65D: Manufactured by Matsumoto Oil Pharmaceutical Co., Ltd., trade name "Matsumoto Microsphere F-65D", foaming (expansion) starting temperature: 105 ° C to 115 ° C, maximum expansion temperature: 145 ° C to 155 ° C, average particle size 12µm ~ 18μm

FN-180SSD: "Matsumoto Microsphere FN-180SSD" manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd., foaming (expansion) starting temperature: 135 ° C ~ 150 ° C, maximum expansion temperature: 165 ° C ~ 180 ° C, average particle size 15μm ~ 25μm

F-260D: Manufactured by Matsumoto Oil Pharmaceutical Co., Ltd., trade name "Matsumoto Microsphere F-260D", foaming (expansion) starting temperature: 190 ° C to 200 ° C, maximum expansion temperature: 250 ° C to 260 ° C, average particle size 20μm ~ 35μm

<Active energy ray reactive oligomer>

UV1700B: Made by Nippon Synthetic Chemical Co., Ltd., trade name "Purple UV-1700B", UV-curable acrylic urethane

UV7620EA: Made by Nippon Synthetic Chemical Co., Ltd., trade name "Purple UV-7620EA", UV-curable acrylic urethane

UV3000B: manufactured by Nippon Synthetic Chemical Co., Ltd., trade name "Purple UV-3000B", UV-curable acrylic urethane

M321: manufactured by Toa Synthesis, trade name "Aronix M321", trimethylolpropane PO modified triacrylate (average addition mole number of propylene oxide (PO): 2 mole)

UV7630B: Made by Nippon Synthetic Chemical Co., Ltd., trade name "Purple UV-7630B", UV-curable acrylic urethane

<Energy ray polymerization initiator>

I184: manufactured by BASF under the trade name "Irgacure 184"

I2959: "Irgacure 2959" manufactured by BASF

I651: manufactured by BASF under the trade name "Irgacure 651"

[Example 16]

A toluene solution (Polymer 1: 100 parts) of Polymer 1 prepared in Production Example 1 and 0.8 parts of an epoxy-based cross-linking agent (manufactured by Mitsubishi Gas Chemical Co., Ltd. under the trade name "Tetrad C") were used as a tackifier. 30 parts of terpene-phenol resin (manufactured by Yasuhara Chemical Co., trade name "YS Polystar S145") and thermally expandable microspheres (manufactured by Matsumoto Oil & Gas Pharmaceutical Co., Ltd., trade name "Matsumoto Microsphere F-50D", foaming (expansion)) (Starting temperature: 95 ° C. to 105 ° C., maximum expansion temperature: 125 ° C. to 135 ° C., average particle diameter 10 μm to 18 μm) 30 parts were mixed to prepare a mixed solution. To the mixed solution is further added to the mixed solution. Solvent (toluene) with the same solvent, adjust the viscosity to a viscosity that is easy to apply. Using an applicator, the mixed solution was coated on a polyethylene terephthalate film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.) with a silicone release agent-treated surface so that the thickness of the solvent after evaporation (drying) reached 30 μm. (Trade name: "MRF38", thickness: 38 µm), and then dried to form an adhesive layer precursor layer on the polyethylene terephthalate film.

Using the hand pressure roller, the adhesive surface of the above-mentioned adhesive layer precursor layer was adhered to the matte polyethylene terephthalate film (manufactured by Toray Corporation, trade name "Lumirror Type X42", thickness: 50 μm). Treatment surface. An autoclave process (40 ° C, 5 Kgf / cm ² , 10 minutes) was performed to obtain an adhesive sheet (adhesive layer (thickness: 30 μm) / tethering layer (polyethylene terephthalate, thickness: 50 μm)).

[Example 17]

A toluene solution (Polymer 4: 100 parts) of Polymer 4 prepared in Production Example 4 and 0.8 parts of an epoxy-based cross-linking agent (manufactured by Mitsubishi Gas Chemical Co., trade name "Tetrad C") were used as a tackifier. 5 parts of terpene-phenol resin (manufactured by Yasuhara Chemical Co., trade name "YS Polystar S145") and thermally expandable microspheres (manufactured by Matsumoto Oil & Gas Pharmaceutical Co., Ltd., trade name "Matsumoto Microsphere F-50D", foaming (expansion)) (Starting temperature: 95 ° C. to 105 ° C., maximum expansion temperature: 125 ° C. to 135 ° C., average particle diameter 10 μm to 18 μm) 30 parts were mixed to prepare a mixed solution. The same solvent (toluene) as the solvent in the mixed solution was further added to the mixed solution, and the viscosity was adjusted to a viscosity for easy application. Using an applicator, the mixed solution was coated on a polyethylene terephthalate film (Mitsubishi Chemical Polyester Film Co., Ltd.) with a silicone release agent-treated surface so that the thickness of the solvent was 40 μm after the solvent was evaporated (dried). (Manufactured, trade name "MRF38", thickness: 38 μm), and then dried to form an adhesive layer precursor layer on the polyethylene terephthalate film.

Using a wire rod applicator (10), a mixed solvent of ethyl acetate and dimethylformamide (ethyl acetate: dimethylformamide = 1: 10 (vol%)) was applied as a mooring Layer of polyethylene terephthalate film (Diafix (PG-CHI (FG, thickness 200 μm))) On one surface, a hand pressure roller is used to adhere the adhesive surface of the foregoing adhesive layer precursor layer to the coated surface. It dried at 80 degreeC for 3 minutes with the hot air dryer, and obtained the adhesive sheet (adhesive layer (thickness: 40 micrometers) / tethering layer (polyethylene terephthalate, thickness: 200 micrometers)).

It is clear from Table 1 that the adhesive sheet of the present invention can reduce the adhesive force by heating, and can achieve excellent cutting accuracy when cutting the adherend.

[Industrial availability]

The manufacturing method and the adhesive sheet of the present invention can be suitably used for manufacturing wafer-shaped electronic parts such as semiconductor wafers.

Claims (10)

An adhesive sheet is provided with an adhesive layer containing a plurality of thermally expandable microspheres, and a mooring layer disposed on one side of the adhesive layer. At least one or more thermally expandable microspheres protrude from the adhesive layer. The thermally expandable microspheres are embedded in a captive layer, and the elastic modulus of the captive layer measured by the nanoindentation method at 25 ° C is 1 MPa to 5000 MPa. The adhesive sheet according to claim 1, wherein the adhesive layer contains thermally expandable microspheres having a particle diameter larger than a thickness of the adhesive layer. For example, the adhesive sheet of claim 1, wherein the height of the part of the thermally expandable microspheres protruding from the adhesive layer is 0.4 μm or more. For example, the adhesive sheet of claim 1, wherein the length (11) of the interface between the adhesive layer and the mooring layer is observed under a cross-section of a specific area including the part where the thermally expandable microspheres protrude from the adhesive layer. The ratio (11 / L) of the length (L) of the projection line in the thickness direction of this interface is 1.02 or more. For example, the adhesive sheet of claim 1, wherein the average particle diameter of the thermally expandable microspheres is 6 μm to 45 μm. The adhesive sheet according to claim 1, wherein the thickness of the above-mentioned adhesive layer is 20 μm or less. For example, in the adhesive sheet of claim 1, when the thermally expandable microspheres are expanded or foamed by heating, the surface roughness Ra of the surface of the adhesive layer on the side opposite to the mooring layer is 3 μm or more. For example, the adhesive sheet of claim 1, wherein the elastic modulus of the above-mentioned adhesive layer measured by the nanoindentation method at 25 ° C does not reach 100 MPa. For example, the adhesive sheet of claim 1 further includes a base material on the side of the mooring layer opposite to the adhesive layer. An electronic component manufacturing method includes: after attaching an electronic component material to an adhesive sheet according to any one of claims 1 to 9, cutting the electronic component material.