Work handling sheet, method for manufacturing semiconductor device, and use of work handling sheet

Abstract

A workpiece handling sheet 1 comprises: a substrate 13; an interface abrasion layer 12 laminated on one side of the substrate 13, and capable of interface abrasion through irradiation with laser light; and an adhesive layer 11 laminated on the surface side of the interface abrasion layer 12 opposite to the substrate 13, and composed of a curable film-like adhesive. According to the workpiece handling sheet 1, a small workpiece with a film-like adhesive can be obtained satisfactorily.

Description

Technical Field

[0001] The present invention relates to a work handling sheet that can be used to handle a work such as a semiconductor wafer, a method for manufacturing a semiconductor device using the work handling sheet, and the use of the work handling sheet.

Background Art

[0002] A semiconductor chip is usually die-bonded to a circuit formation surface of a substrate by a film-like adhesive provided on its back surface. Thereafter, if necessary, one or more semiconductor chips are further stacked on this semiconductor chip, wire bonding is performed, and then the obtained whole is sealed with resin to produce a semiconductor package. Then, a target semiconductor device is produced using this semiconductor package.

[0003] A semiconductor chip having a film-like adhesive on its back surface is produced, for example, by dividing a semiconductor wafer having a film-like adhesive on its back surface and also cutting the film-like adhesive. As a method of dividing a semiconductor wafer into semiconductor chips in this way, for example, a method of dicing a semiconductor wafer together with the film-like adhesive using a dicing blade is widely used. In this case, the film-like adhesive before cutting is used as a dicing die bonding sheet that is laminated and integrated with a support sheet used to fix the semiconductor wafer during dicing.

[0004] After dicing, a semiconductor chip having a cut film-like adhesive on its back surface (a semiconductor chip with a film-like adhesive) is separated from the support sheet and picked up.

[0005] For example, Patent Document 1 discloses a dicing and die bonding sheet (corresponding to the dicing die bonding sheet) comprising a base material, a wire embedding layer peelably laminated on the base material, a heat-resistant insulating film laminated on the wire embedding layer, and an adhesive layer formed on the heat-resistant insulating film (corresponding to the above-mentioned film-like adhesive). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2007-53240 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, in recent years, semiconductor wafers have become extremely thin, making it easier for various problems to occur when picking up semiconductor chips with film-like adhesive. For example, if the adhesion between the film-like adhesive and the layer below it (substrate, etc.) is too high, the force required to separate the film-like adhesive semiconductor chip from the dicing die bonding sheet becomes too great, which can damage the semiconductor chip. Conversely, if the adhesion is too low, problems can arise during pickup, such as the separation of adjacent semiconductor chips or the random separation of semiconductor chips at unintended stages.

[0008] This invention has been made in view of the above circumstances, and aims to provide a work handling sheet that can successfully produce small workpieces with a film-like adhesive. [Means for solving the problem]

[0009] To achieve the above objective, firstly, the present invention provides a work handling sheet comprising a base material, an interface ablation layer laminated on one side of the base material and capable of interface ablation by irradiation with laser light, and an adhesive layer made of a curable film-like adhesive laminated on the side of the interface ablation layer opposite to the base material (Invention 1).

[0010] The work handling sheet according to the above invention (Invention 1) is equipped with the aforementioned interface ablation layer, and by irradiating the interface ablation layer with laser light, interface ablation can be caused in the interface ablation layer, thereby changing the shape of the interface ablation layer. Therefore, after obtaining small workpieces with film-like adhesive by separating the adhesive layer together with the workpiece on the work handling sheet, the above-mentioned interface ablation can be caused to create a trigger for separating the film-like adhesive (fragmented adhesive layer) from the interface ablation layer, making it possible to easily separate the small workpieces with film-like adhesive.

[0011] In the above invention (Invention 1), the interfacial ablation layer is preferably an adhesive layer (Invention 2).

[0012] In the above inventions (Inventions 1 and 2), it is preferable that the interfacial ablation layer contains at least one additive, which is an ultraviolet absorber and a photopolymerization initiator (Invention 3).

[0013] In the above inventions (Inventions 1 to 3), it is preferable that the laser light has a wavelength in the ultraviolet region (Invention 4).

[0014] In the above inventions (Inventions 1 to 4), it is preferable that a blister is formed at the location where the interface ablation occurs when interface ablation is caused in the interface ablation layer (Invention 5).

[0015] In the above inventions (Inventions 1 to 5), it is preferable that the workpiece is held on the surface of the adhesive layer opposite to the interface ablation layer, and the workpiece is fragmented together with the adhesive layer to obtain a plurality of laminates consisting of small pieces of the workpiece and small pieces of the adhesive layer, and then at least one of these laminates is used to selectively separate from the interface ablation layer by interface ablation locally generated in the interface ablation layer (Invention 6).

[0016] Secondly, the present invention provides a method for manufacturing a semiconductor device (Invention 7), characterized by comprising: a fragmentation step of obtaining a plurality of laminates consisting of small pieces of the work and small pieces of the adhesive layer by fragmenting the work together with the adhesive layer while holding the work on the adhesive layer side surface of the work handling sheet (Inventions 1 to 6); an irradiation step of irradiating the interface ablation layer with laser light at a position where at least one of the laminates is held to cause interface ablation at the irradiated position in the interface ablation layer; and a pickup step of picking up the laminate located at the position where interface ablation has occurred from the work handling sheet.

[0017] Thirdly, the present invention provides a use of the work handling sheet (Inventions 1 to 6) for manufacturing a semiconductor device, wherein the method for manufacturing the semiconductor device comprises: a framing step of obtaining a plurality of laminates consisting of small pieces of the work and small pieces of the adhesive layer by framing the work together with the adhesive layer while holding the work on the adhesive layer side surface of the work handling sheet; an irradiation step of irradiating the interface ablation layer with laser light at a position where at least one of the laminates is held to cause interface ablation at the irradiated position in the interface ablation layer; and a pickup step of picking up the laminate located at the position where interface ablation has occurred from the work handling sheet (Invention 8).

Advantages of the Invention

[0018] The work handling sheet according to the present invention can preferably obtain a work piece with a film-like adhesive.

Brief Description of the Drawings

[0019] [Figure 1] FIG. 13 is a cross-sectional view of an example of a work handling sheet according to an embodiment of the present invention. [Figure 2] FIG. 16 is a cross-sectional view of another example of a work handling sheet according to an embodiment of the present invention. [Figure 3] FIG. 19 is a cross-sectional view for explaining a method of manufacturing a semiconductor device using a work handling sheet according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described. FIGS. 1 and 2 show cross-sectional views of a work handling sheet according to an embodiment. The work handling sheet 1 shown in FIGS. 1 and 2 includes a base material 13, an interface ablation layer 12 laminated on one side of the base material 13, and an adhesive layer 11 laminated on the side of the interface ablation layer 12 opposite to the base material 13.

[0021] The work handling sheet 1 shown in FIG. 1 is drawn such that the size of the adhesive layer 11 in the lateral direction of the drawing paper is the same as those of the interface ablation layer 12 and the base material 13. In the work handling sheet 1 according to the present embodiment, the adhesive layer 11 may be configured to have substantially the same shape as the interface ablation layer 12 and the base material 13 in plan view.

[0022] On the one hand, the work handling sheet 1 shown in FIG. 2 is drawn such that the size of the adhesive layer 11 in the lateral direction of the paper surface is smaller than those of the interface ablation layer 12 and the base material 13. In the work handling sheet 1 according to the present embodiment, the adhesive layer 11 may be configured to have a shape smaller than those of the interface ablation layer 12 and the base material 13 in plan view in this way.

[0023] In the work handling sheet 1 according to the present embodiment, the interface ablation layer 12 is configured to undergo interface ablation by irradiation with laser light. That is, the interface ablation layer 12 undergoes local interface ablation in the region irradiated with the laser light.

[0024] In this specification, interface ablation refers to the evaporation or volatilization of a part of the components constituting the interface ablation layer 12 by the energy of the laser light, and the gas generated thereby accumulates at the interface between the interface ablation layer 12 and the base material 13 to form voids (blisters).

[0025] In the work handling sheet 1 according to the present embodiment, by generating the blisters, the shape of the interface ablation layer 12 can be deformed. Along with this, a separation trigger can be favorably generated at the interface between the work handling sheet 1 and the work piece (or work) attached thereto. Therefore, according to the work handling sheet 1 according to the present embodiment, even when an extremely thin work or a brittle work is used, the breakage of the work can be prevented and the work can be favorably separated from the work handling sheet 1.

[0026] In particular, because the above-described action facilitates separation, it becomes possible to design the adhesive layer 11 to have relatively high adhesion, thereby suppressing the separation of the workpiece or workpiece fragments at unintended stages, as well as the separation of adjacent workpiece fragments during pickup. Furthermore, since the above-described interface ablation can be caused locally at the location where the laser light is irradiated, selective separation of only the intended workpiece fragments can be performed effectively.

[0027] Furthermore, in the work handling sheet 1 according to this embodiment, the adhesive layer 11 is made of a curable film-like adhesive. In the work handling sheet 1 according to this embodiment, a workpiece such as a semiconductor wafer is attached to the surface on the adhesive layer 11 side, and the adhesive layer 11 is divided (diced) together with the workpiece, thereby obtaining a workpiece with a film-like adhesive, in which workpiece pieces formed from individual pieces of the workpiece and film-like adhesive formed from individual pieces of the adhesive layer 11 are laminated. Then, by performing interfacial ablation as described above, the obtained workpiece with a film-like adhesive can be easily separated from the work handling sheet 1.

[0028] Examples of workpieces that can be handled by the work handling sheet 1 according to this embodiment include semiconductor wafers, semiconductor packages, glass plates, etc. By dividing these, it is possible to obtain workpiece fragments such as semiconductor chips, divided semiconductor packages, glass fragments, etc.

[0029] Furthermore, the laser light that can be used in the work handling sheet 1 according to this embodiment is not particularly limited as long as it is capable of causing interfacial ablation, and may be a laser light having a wavelength in the ultraviolet, visible, or infrared region, with a laser light having a wavelength in the ultraviolet region being preferred.

[0030] 1.Adhesive layer The specific structure and composition of the adhesive layer 11 in this embodiment are not particularly limited, as long as it consists of a curable film-like adhesive. From the viewpoint of easily exhibiting the desired performance as an adhesive layer, it is preferable that the adhesive layer 11 in this embodiment is formed using an adhesive composition containing at least one of a thermosetting component and an active energy ray curable resin. Furthermore, it is also preferable that the adhesive composition contains at least one of the above-mentioned components, including an acrylic polymer, a curing accelerator, an inorganic filler, a coupling agent, a crosslinking agent, and a photopolymerization initiator. These components will be described below.

[0031] (1) Acrylic polymer The composition of the acrylic polymer is not particularly limited. Examples of monomers constituting the acrylic polymer include alkyl (meth)acrylates, and in particular, alkyl (meth)acrylates in which the alkyl group has 1 to 18 carbon atoms are preferred. Specifically, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, etc. are preferably used. These may be used individually or in combination of two or more. In this specification, (meth)acrylic acid ester means both acrylic acid ester and methacrylic acid ester. The same applies to other similar terms.

[0032] Furthermore, examples of monomers constituting the above-mentioned acrylic polymer include monomers containing carboxyl groups and monomers containing hydroxyl groups.

[0033] Examples of carboxyl group-containing monomers include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. These may be used individually or in combination of two or more.

[0034] Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate, which can be used individually or in combination of two or more.

[0035] Other examples of monomers include monomers with a cyclic skeleton and monomers with an epoxy group.

[0036] Preferred monomers having a cyclic skeleton include cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and (meth)acrylimide. These may be used individually or in combination of two or more.

[0037] As the monomer having the epoxy group described above, glycidyl (meth)acrylate is preferably used.

[0038] The weight-average molecular weight of the acrylic polymer is preferably 10,000 or more, particularly preferably 200,000 or more, and even more preferably 400,000 or more. Furthermore, the weight-average molecular weight is preferably 1,000,000 or less, particularly preferably 800,000 or less, and even more preferably 800,000 or less. In this specification, the weight-average molecular weight (Mw) is a value on a standard polystyrene basis measured by gel permeation chromatography (GPC).

[0039] Acrylic polymers may be used individually or in combination of two or more types.

[0040] When the adhesive composition contains an acrylic polymer, the content of the acrylic polymer in the adhesive composition is preferably 10% by mass or more, particularly preferably 12% by mass or more, and more preferably 14% by mass or more. Furthermore, the content is preferably 30% by mass or less, preferably 25% by mass or less, and more preferably 14% by mass or less. Having the acrylic polymer content within the above range results in better adhesive properties as a film-like adhesive.

[0041] (2) Thermosetting component The thermosetting component is a component that has thermosetting properties and is used to heat-cur the film-like adhesive. The thermosetting component is not limited as long as it has thermosetting properties, but for example, epoxy thermosetting resins, polyimide resins, unsaturated polyester resins, etc. are preferred. The adhesive composition may contain one thermosetting component alone or two or more components in combination.

[0042] In this embodiment, among the examples above, it is preferable to use an epoxy-based thermosetting resin consisting of an epoxy resin and a thermosetting agent as the thermosetting component. The epoxy-based thermosetting resin may be used alone or in combination of two or more types.

[0043] (2-1) Epoxy resin Examples of epoxy resins include well-known ones, such as polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenated products, o-cresol novolac type epoxy resins, dicyclopentadiene type epoxy resins, biphenyl type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenylene skeleton type epoxy resins, and other bifunctional or more epoxy compounds. In this specification, epoxy resin refers to an epoxy resin that is curable, i.e., an uncured epoxy resin.

[0044] The number average molecular weight of the epoxy resin is not particularly limited, but from the viewpoint of the curability of the film-like adhesive and the strength and heat resistance of the thermoset product of the film-like adhesive, it is preferably 300 or more, particularly preferably 400 or more, and even more preferably 500 or more. Furthermore, the number average molecular weight is preferably 30,000 or less, particularly preferably 10,000 or less, and even more preferably 3,000 or less.

[0045] The epoxy equivalent of the epoxy resin is preferably 100 g / eq or more, and particularly preferably 150 g / eq or more. Furthermore, the epoxy equivalent is preferably 1000 g / eq or less, and particularly preferably 800 g / eq or less.

[0046] Epoxy resins may be used individually or in combination of two or more types.

[0047] When using epoxy resin, the epoxy resin content in the adhesive composition is preferably 40% by mass or more, particularly preferably 46% by mass or more, and even more preferably 48% by mass or more. Furthermore, the above content is preferably 65% ​​by mass or less, particularly preferably 60% by mass or less, and even more preferably 58% by mass or less.

[0048] Furthermore, either a liquid epoxy resin at room temperature or a solid epoxy resin at room temperature may be used as the epoxy resin. When a liquid epoxy resin at room temperature is used, the content of the epoxy resin in the adhesive composition is preferably 2% by mass or more, more preferably 3% by mass or more, and even more preferably 4% by mass or more. A content of 2% by mass or more facilitates die bonding to the circuit formation surface at low temperatures. In addition, the content is preferably 20% by mass or less, more preferably 18% by mass or less, and even more preferably 16% by mass or less. A content of 20% by mass or less provides better shape stability for the film-like adhesive.

[0049] (2-2) Thermosetting agent A thermosetting agent is a curing agent for epoxy resins. The combination of epoxy resin and thermosetting agent functions as an epoxy-based thermosetting resin. Examples of thermosetting agents include compounds having two or more functional groups that can react with epoxy groups in one molecule. Examples of such functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and groups in which an acid group has been anhydroused. Among these, at least one of phenolic hydroxyl groups, amino groups, and groups in which an acid group has been anhydroused is preferred, and at least one of phenolic hydroxyl groups and amino groups is particularly preferred.

[0050] Examples of thermosetting agents that have a phenolic hydroxyl group include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins. Examples of amine-type curing agents that have an amino group include dicyandiamide (DICY).

[0051] Furthermore, the thermosetting agent may have an unsaturated hydrocarbon group. Examples of thermosetting agents having an unsaturated hydrocarbon group include compounds in which some of the hydroxyl groups of a phenolic resin are replaced with a group having an unsaturated hydrocarbon group, and compounds in which a group having an unsaturated hydrocarbon group is directly bonded to the aromatic ring of a phenolic resin.

[0052] When using a phenolic curing agent as a thermosetting agent, it is preferable to use a thermosetting agent with a high softening point or glass transition temperature, as this makes it easier to adjust the adhesive strength of the film-like adhesive.

[0053] Among the thermosetting agents, the number average molecular weight of the resin components, such as polyfunctional phenolic resins, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins, is preferably 300 or more, particularly preferably 400 or more, and even more preferably 500 or more. Furthermore, the number average molecular weight is preferably 30,000 or less, particularly preferably 10,000 or less, and even more preferably 3,000 or less.

[0054] Among the thermosetting agents, the molecular weight of non-resin components such as biphenol and dicyandiamide is not particularly limited, but is preferably, for example, 60 or more and 500 or less.

[0055] The thermosetting agent is preferably an o-cresol type novolac resin, more specifically represented by the following general formula (1).

[0056] [ka]

[0057] In general formula (1), n ​​is an integer of 1 or more, and may be, for example, 2 or more, 4 or more, or 6 or more. The upper limit of n is not particularly limited as long as it does not impair the effects of the present invention. For example, o-cresol type novolac resins in which n is 10 or less are easier to manufacture or obtain.

[0058] In general formula (1), the bonding position of the methylene group (-CH2-) linking the o-cresol-diyl groups (-C6H4(-OH)(-CH3)-) to these o-cresol-diyl groups is not particularly limited.

[0059] As a thermosetting agent, as is clear from general formula (1), it is preferable that the phenolic resin has a structure in which a methyl group is bonded to the carbon atom adjacent to the carbon atom to which the phenolic hydroxyl group is bonded (a carbon atom constituting the benzene ring skeleton), and that it has steric hindrance near the phenolic hydroxyl group. It is presumed that the reactivity of the thermosetting agent during storage is suppressed due to such steric hindrance. It is presumed that by using such a thermosetting agent, the reaction of its components, such as the curable components, during storage of the film-like adhesive is suppressed, and changes in its properties are suppressed. It is presumed that a highly reliable semiconductor package can be obtained by using such a film-like adhesive and a semiconductor chip.

[0060] Film-like adhesives using thermosetting agents represented by general formula (1) have high storage stability and can be stored at room temperature. For the same reason, adhesive compositions also have high storage stability and can be stored at room temperature.

[0061] The thermosetting agent may be used individually or in combination of two or more types.

[0062] When a thermosetting agent is used, the content of the thermosetting agent in the adhesive composition is preferably 10% by mass or more, particularly preferably 15% by mass or more, and even more preferably 20% by mass or more. A content of 10% by mass or more facilitates the curing of the film-like adhesive. Furthermore, the content is preferably 50% by mass or less, particularly preferably 45% by mass or less, and even more preferably 40% by mass or less. A content of 50% by mass or less reduces the moisture absorption rate of the film-like adhesive, thereby improving the reliability of the semiconductor package obtained using the film-like adhesive.

[0063] Furthermore, when using an epoxy-based thermosetting resin obtained by combining epoxy resin and a thermosetting agent, the content of the epoxy-based thermosetting resin in the adhesive composition is preferably 60% by mass or more, and particularly preferably 65% ​​by mass or more. A content of 60% by mass or more makes it easier to improve bonding properties. Also, the content is preferably 85% by mass or less, and particularly preferably 80% by mass or less. A content of 85% by mass or less improves storage stability.

[0064] The content of the thermosetting agent per 100 parts by mass of the acrylic polymer is preferably more than 400 parts by mass, particularly preferably 410 parts by mass or more, and even more preferably 420 parts by mass or more. This range improves the heat resistance and adhesive strength of the thermoset film adhesive, further enhancing the reliability of the semiconductor package. The upper limit of the thermosetting agent content per 100 parts by mass of the acrylic polymer may be, for example, 700 parts by mass or less, 600 parts by mass or less, or 500 parts by mass or less.

[0065] The softening point of the thermosetting agent is preferably 60°C or higher, more preferably 64°C or higher, particularly preferably 68°C or higher, even more preferably 72°C or higher, and most preferably 76°C or higher. Furthermore, the softening point of the thermosetting agent is preferably 130°C or lower, more preferably 120°C or lower, particularly preferably 110°C or lower, even more preferably 100°C or lower, and most preferably 90°C or lower.

[0066] (3) Curing accelerator Curing accelerators are components for adjusting the curing rate of adhesive compositions and film-like adhesives. Preferred curing accelerators include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms); organophosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (phosphines in which one or more hydrogen atoms are substituted with organic groups); and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

[0067] The curing accelerator may be used individually or in combination of two or more types.

[0068] When using a curing accelerator, the content of the curing accelerator is preferably 0.01 parts by mass or more, and particularly preferably 0.1 parts by mass or more, per 100 parts by mass of epoxy thermosetting resin (i.e., total content of epoxy resin and thermosetting agent). A content of 0.01 parts by mass or more allows for a more pronounced effect from using the curing accelerator. Furthermore, the content of the curing accelerator is preferably 5 parts by mass or less, and particularly preferably 2 parts by mass or less, per 100 parts by mass of epoxy thermosetting resin. A content of 5 parts by mass or less enhances the effect of suppressing, for example, the migration and segregation of highly polar curing accelerators towards the adhesive interface with the adherend in the film-like adhesive under high temperature and high humidity conditions, thereby further improving the reliability of semiconductor packages obtained using the film-like adhesive.

[0069] (4) Inorganic filler By incorporating inorganic fillers, the thermal expansion coefficient of film-type adhesives can be easily adjusted. Optimizing this thermal expansion coefficient for the object to which the film-type adhesive is applied further improves the reliability of semiconductor packages obtained using the film-type adhesive. Furthermore, the inclusion of inorganic fillers in film-type adhesives can reduce the moisture absorption rate of the thermosetting product and improve heat dissipation.

[0070] Preferred inorganic fillers include, for example, powders such as silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, and boron nitride; beads formed from these inorganic fillers in a spherical shape; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; and glass fibers.

[0071] Among these, the inorganic filler is preferably silica, alumina, or a surface-modified version thereof.

[0072] The average particle size of the inorganic filler is not particularly limited, but is preferably 10 nm or larger, more preferably 20 nm or larger, and even more preferably 30 nm or larger. Furthermore, the average particle size is preferably 300 nm or smaller, more preferably 150 nm or smaller, and even more preferably 100 nm or smaller. Having the average particle size of the inorganic filler within this range allows for the full benefit of using the inorganic filler and further enhances the storage stability of the film-like adhesive.

[0073] In this specification, unless otherwise specified, "average particle diameter" refers to the particle diameter (D50) at 50% integration in the particle size distribution curve obtained by laser diffraction scattering.

[0074] Inorganic fillers may be used individually or in combination of two or more types.

[0075] When using inorganic fillers, the ratio of the inorganic filler content to the total content of all components other than the solvent in the adhesive composition is preferably 2% by mass or more, more preferably 4% by mass or more, and even more preferably 6% by mass or more. Furthermore, the above ratio is preferably 15% by mass or less, more preferably 12% by mass or less, and even more preferably 10% by mass or less. Having the inorganic filler content within this range makes it easier to adjust the coefficient of thermal expansion.

[0076] However, to further reduce transfer defects, it is preferable to have a low inorganic filler content. From this viewpoint, the ratio of the inorganic filler content to the total content of all components other than the solvent is preferably 2% by mass or less, particularly preferably 1% by mass or less, and even more preferably substantially free of inorganic fillers. By reducing the inorganic filler content, it is possible to suppress the decrease in cohesive strength as a film-like adhesive, and as a result, the occurrence of transfer defects can be suppressed.

[0077] (5) Coupling agent The presence of a coupling agent in the film-type adhesive improves its adhesion and bonding properties to the substrate. Furthermore, the presence of a coupling agent in the film-type adhesive improves the water resistance of the thermosetting product without compromising its heat resistance. The coupling agent has a functional group that can react with inorganic or organic compounds.

[0078] The coupling agent is preferably a compound having a functional group that can react with the functional groups of an acrylic polymer, epoxy thermosetting resin, etc., and more preferably a silane coupling agent.

[0079] Preferred silane coupling agents include, for example, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, and 3-(2-aminoethylamino)propyl Examples include methyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfan, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazolesilane, oligomeric or polymeric organosiloxanes, etc.

[0080] The coupling agent may be used alone or in combination of two or more types.

[0081] When a coupling agent is used, the content of the coupling agent in the adhesive composition is preferably 0.03 parts by mass or more, particularly preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, based on 100 parts by mass of the total content of the acrylic polymer and epoxy thermosetting resin. When the content of the coupling agent is 0.03 parts by mass or more, the effects of using the coupling agent are more pronounced, such as improved dispersibility of the inorganic filler in the resin and improved adhesion of the film adhesive to the adherend. Furthermore, the content of the coupling agent is preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, based on 100 parts by mass of the total content of the acrylic polymer and epoxy thermosetting resin. When the content of the coupling agent is 20 parts by mass or less, outgassing is further suppressed.

[0082] (6) Crosslinking agents When using acrylic polymers or other materials having functional groups such as vinyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, carboxyl groups, and isocyanate groups that can bond with other compounds, the adhesive composition and the film-like adhesive may contain a crosslinking agent for crosslinking the functional groups with other compounds. By crosslinking with a crosslinking agent, the initial adhesive strength and cohesive strength of the film-like adhesive can be adjusted.

[0083] Examples of crosslinking agents include organic polyvalent isocyanate compounds, organic polyvalent imine compounds, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure), and aziridine crosslinking agents (crosslinking agents having an aziridinyl group).

[0084] Examples of the above-mentioned organic polyvalent isocyanate compounds include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, and alicyclic polyvalent isocyanate compounds (hereinafter, these compounds may be collectively abbreviated as "aromatic polyvalent isocyanate compounds, etc."); trimers, isocyanurates, and adducts of the above-mentioned aromatic polyvalent isocyanate compounds, etc.; and terminal isocyanate urethane prepolymers obtained by reacting the above-mentioned aromatic polyvalent isocyanate compounds, etc. with polyol compounds. The above-mentioned "adduct" refers to the reaction product of the above-mentioned aromatic polyvalent isocyanate compound, aliphatic polyvalent isocyanate compound, or alicyclic polyvalent isocyanate compound with a low-molecular-weight active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, or castor oil. Examples of the above-mentioned adduct include the xylylene diisocyanate adduct of trimethylolpropane, as described later. Furthermore, "terminal isocyanate urethane prepolymer" refers to a prepolymer that has urethane bonds and isocyanate groups at the ends of the molecule.

[0085] More specifically, examples of the above-mentioned organic polyvalent isocyanate compounds include, for example, 2,4-tolylene diisocyanate; 2,6-tolylene diisocyanate; 1,3-xylylene diisocyanate; 1,4-xylylene diisocyanate; diphenylmethane-4,4'-diisocyanate; diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; compounds in which one or more of tolylene diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate are added to all or some of the hydroxyl groups of polyols such as trimethylolpropane; and lysine diisocyanate.

[0086] Examples of the above-mentioned organic polyvalent imine compounds include N,N'-diphenylmethane-4,4'-bis(1-aziridinylcarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, and N,N'-toluene-2,4-bis(1-aziridinylcarboxamide)triethylenemelamine.

[0087] When using an organic polyvalent isocyanate compound as a crosslinking agent, it is preferable to use a hydroxyl group-containing polymer as the acrylic polymer. When the crosslinking agent has an isocyanate group and the acrylic polymer has a hydroxyl group, a crosslinked structure can be easily introduced into the film-like adhesive by the reaction between the crosslinking agent and the acrylic polymer.

[0088] The crosslinking agent may be used alone or in combination of two or more types.

[0089] The crosslinking agent content is preferably 0 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.2 parts by mass or more, based on the acrylic polymer content per 100 parts by mass. A crosslinking agent content of 0 parts by mass or more allows for a more pronounced effect from the use of the crosslinking agent. Furthermore, the crosslinking agent content is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 1 part by mass or less, based on the acrylic polymer content per 100 parts by mass. A crosslinking agent content of 5 parts by mass or less further improves the storage stability of the film-like adhesive.

[0090] (7) Active energy ray curable resin Active energy ray curable resins are cured by irradiation with active energy rays. Specific examples of active energy ray curable resins include polyfunctional (meth)acrylate monomers, (meth)acrylate prepolymers, and active energy ray curable polymers. Among these, polyfunctional (meth)acrylate monomers are more preferred.

[0091] Examples of polyfunctional (meth)acrylate monomers include monofunctional acrylic acid esters such as cyclohexyl (meth)acrylate and isobornyl (meth)acrylate, polyfunctional acrylic acid esters such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and dimethylol tricyclodecane di(meth)acrylate, as well as polyester oligo(meth)acrylate and polyurethane oligo(meth)acrylate.

[0092] When using an active energy ray-curable resin, the content of the active energy ray-curable resin in the adhesive composition is preferably 20% by mass or less, particularly preferably 10% by mass or less, and even more preferably 5% by mass or less. A content of 20% by mass or less of the active energy ray-curable resin makes it easier to separate the film-like adhesive (adhesive layer 11) from the interfacial ablation layer 12. Furthermore, the content of the active energy ray-curable resin in the adhesive composition may be 0.1% by mass or more, and particularly preferably 2% by mass or more. A content of 0.1% by mass or more of the active energy ray-curable resin improves the curability of the film-like adhesive.

[0093] (8) Photopolymerization initiator If the adhesive composition contains an active energy ray-curable resin, it is also preferable to include a photopolymerization initiator. This allows the film-like adhesive to cure more effectively.

[0094] The above photopolymerization initiators specifically include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, and 1-hydroxycycline. Rohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-phenyl)butan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxymethylpropanone, ethanone, 1-[9-ethyl-6-(2-methylbenzyl] Zoyl)-9H-carbazole-3-yl]-,1-(0-acetyloxime), benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethyl Examples include thioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, oligo[2-hydroxy-2-methyl-1[4-(1-methylvinyl)phenyl]propanone], 2-benzyl-2-(dimethylamino)-4'-morpholinobtyrophenone, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. These may be used individually or in combination of two or more.

[0095] Furthermore, it is preferable that the photopolymerization initiator has an absorption peak that falls outside the wavelength of the laser light used to induce interfacial ablation. This makes it easier to effectively induce interfacial ablation when irradiated with laser light.

[0096] When using a photopolymerization initiator, its content is preferably selected appropriately in accordance with the content of the active energy ray-curable resin. For example, the content of the photopolymerization initiator in the adhesive composition is preferably 0.5% by mass or more, and particularly preferably 1% by mass or more. A photopolymerization initiator content of 0.5% by mass or more allows the active energy ray-curable resin in the film-like adhesive to cure more efficiently. Furthermore, the content of the photopolymerization initiator in the adhesive composition is preferably 15% by mass or less, and particularly preferably 10% by mass or less. A photopolymerization initiator content of 15% by mass or less improves the storage stability of the film-like adhesive.

[0097] (9) Other ingredients The adhesive composition may contain components other than those described above. For example, it may contain plasticizers, antistatic agents, antioxidants, colorants (dyes, pigments), gettering agents, etc. These may be used individually or in combination of two or more.

[0098] (10) Method for preparing an adhesive composition The adhesive composition can be obtained by blending the components described above. The order in which the components are added is not particularly limited, and two or more components may be added simultaneously.

[0099] When using a solvent, the solvent may be mixed with any of the other components to pre-dilute the mixture, or the solvent may be mixed with the other components without pre-diluting them.

[0100] The method of mixing each component during formulation is not particularly limited; it can be appropriately selected from known methods such as mixing by rotating a stirring bar or impeller, mixing using a mixer, or mixing by applying ultrasonic waves.

[0101] The temperature and time during the addition and mixing of each component are not particularly limited as long as the components do not deteriorate, and can be adjusted as appropriate, but a temperature of 15 to 30°C is preferred.

[0102] The solvents mentioned above are not particularly limited, but preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone. Among these, toluene and methyl ethyl ketone are preferred because they allow for more uniform mixing of the components in the adhesive composition. These may be used individually or in combination of two or more.

[0103] (11) Thickness In this embodiment, the thickness of the adhesive layer 11 is preferably 1 μm or more, particularly preferably 2 μm or more, and even more preferably 3 μm or more. A thickness of 1 μm or more in the adhesive layer 11 makes it easier to exhibit sufficient adhesive strength to the workpiece. Alternatively, the thickness of the adhesive layer 11 is preferably 30 μm or less, particularly preferably 25 μm or less, and even more preferably 15 μm or less. A thickness of 30 μm or less in the adhesive layer 11 makes it easier to cause separation by interfacial ablation.

[0104] 2. Interface ablation layer The specific configuration and composition of the interface ablation layer 12 in this embodiment are not particularly limited, as long as interface ablation can be performed by irradiation with laser light. A preferred example of the interface ablation layer 12 is an adhesive layer. The interface ablation layer 12 is an adhesive layer, which makes it easier to fix the adhesive layer 11 well.

[0105] If the interfacial ablation layer 12 is an adhesive layer, the adhesive constituting the adhesive layer may be an adhesive that is curable by active energy rays (active energy ray curable adhesive), or it may be an adhesive that is not curable by active energy rays (non-active energy ray curable adhesive).

[0106] Furthermore, the interfacial ablation layer 12 preferably contains at least one additive, such as an ultraviolet absorber and a photopolymerization initiator, from the viewpoint of easily generating good interfacial ablation.

[0107] (1) Active energy ray curable adhesive If the interfacial ablation layer 12 is an adhesive layer composed of an active energy ray curable adhesive, irradiation with active energy rays can reduce the adhesion at the interface between the interfacial ablation layer 12 and the adhesive layer 11 (film-like adhesive). Therefore, by reducing the adhesion by irradiation with active energy rays before or simultaneously with the interfacial ablation described above, it becomes possible to reliably separate the workpiece pieces with the film-like adhesive from the interfacial ablation layer 12. It also becomes possible to reduce the amount of laser light irradiation required to achieve sufficient separation. Furthermore, since the adhesion to the adhesive layer 11 can be reduced by irradiation with active energy rays, it becomes possible to set the adhesion before irradiation with active energy rays to a higher level. This makes it easier to suppress the detachment of the adhesive layer 11 during dicing, etc.

[0108] The above-mentioned active energy ray-curable adhesive may be any of the following: acrylic adhesive, rubber adhesive, silicone adhesive, urethane adhesive, polyester adhesive, polyvinyl ether adhesive, etc. However, from the viewpoint of easily exhibiting the desired adhesive strength, an acrylic adhesive is preferred.

[0109] Furthermore, the active energy ray curable adhesive may be mainly composed of an active energy ray curable polymer, or it may be mainly composed of a mixture of an active energy ray non-curable polymer (a polymer that does not possess active energy ray curability) and a monomer and / or oligomer having at least one active energy ray curable group. Alternatively, it may be a mixture of an active energy ray curable polymer and an active energy ray non-curable polymer, or a mixture of an active energy ray curable polymer and a monomer and / or oligomer having at least one active energy ray curable group, or a mixture of all three.

[0110] First, we will explain the case where the active energy ray-curable adhesive mainly consists of a polymer that is curable by active energy rays.

[0111] The polymer having active energy ray curability is preferably a (meth)acrylic acid ester (co)polymer (A) (hereinafter sometimes referred to as "active energy ray curable polymer (A)") in which an energy ray curable functional group (active energy ray curable group) is introduced into the side chain. This active energy ray curable polymer (A) is preferably obtained by reacting an acrylic copolymer (a1) having a functional group-containing monomer unit with an unsaturated group-containing compound (a2) having a functional group that is bonded to the functional group.

[0112] The acrylic copolymer (a1) preferably contains structural units derived from functional group-containing monomers and structural units derived from (meth)acrylic acid ester monomers or their derivatives.

[0113] The functional group-containing monomer used as a constituent unit of the acrylic copolymer (a1) is preferably a monomer having a polymerizable double bond and a functional group such as a hydroxyl group, carboxyl group, amino group, substituted amino group, or epoxy group within its molecule.

[0114] Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate, which can be used individually or in combination of two or more.

[0115] Examples of carboxyl group-containing monomers include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. These may be used individually or in combination of two or more.

[0116] Examples of amino group-containing monomers or substituted amino group-containing monomers include aminoethyl (meth)acrylate and n-butylaminoethyl (meth)acrylate. These may be used individually or in combination of two or more.

[0117] As the (meth)acrylic acid ester monomer constituting the acrylic copolymer (a1), alkyl (meth)acrylates having 1 to 20 carbon atoms in the alkyl group are preferred, as well as monomers having an alicyclic structure in the molecule (alicyclic structure-containing monomers).

[0118] As alkyl (meth)acrylates, alkyl (meth)acrylates in which the alkyl group has 1 to 18 carbon atoms are particularly preferred, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. These may be used individually or in combination of two or more.

[0119] Preferred monomers containing alicyclic structures include, for example, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, adamantyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate. These may be used individually or in combination of two or more.

[0120] The acrylic copolymer (a1) contains structural units derived from the functional group-containing monomer in a proportion preferably of 1% by mass or more, particularly preferably of 5% by mass or more, and even more preferably of 10% by mass or more. Furthermore, the acrylic copolymer (a1) contains structural units derived from the functional group-containing monomer in a proportion preferably of 35% by mass or less, particularly preferably of 30% by mass or less, and even more preferably of 25% by mass or less.

[0121] Furthermore, the acrylic copolymer (a1) contains constituent units derived from (meth)acrylic acid ester monomers or their derivatives in a proportion preferably of 50% by mass or more, particularly preferably of 60% by mass or more, and even more preferably of 70% by mass or more. In addition, the acrylic copolymer (a1) contains constituent units derived from (meth)acrylic acid ester monomers or their derivatives in a proportion preferably of 99% by mass or less, particularly preferably of 95% by mass or less, and even more preferably of 90% by mass or less.

[0122] Acrylic copolymer (a1) can be obtained by copolymerizing a functional group-containing monomer as described above with a (meth)acrylic acid ester monomer or its derivative by a conventional method. In addition to these monomers, dimethylacrylamide, vinyl formate, vinyl acetate, styrene, etc., may also be copolymerized.

[0123] An active energy ray curable polymer (A) is obtained by reacting an acrylic copolymer (a1) having the above-mentioned functional group-containing monomer units with an unsaturated group-containing compound (a2) having a functional group bonded to the functional group.

[0124] The functional group of the unsaturated group-containing compound (a2) can be appropriately selected according to the type of functional group of the functional group-containing monomer unit of the acrylic copolymer (a1). For example, if the functional group of the acrylic copolymer (a1) is a hydroxyl group, an amino group, or a substituted amino group, the functional group of the unsaturated group-containing compound (a2) is preferably an isocyanate group or an epoxy group. If the functional group of the acrylic copolymer (a1) is an epoxy group, the functional group of the unsaturated group-containing compound (a2) is preferably an amino group, a carboxyl group, or an aziridinyl group.

[0125] Furthermore, the above-mentioned unsaturated group-containing compound (a2) contains at least one, preferably 1 to 6, and more preferably 1 to 4, energy-ray polymerizable carbon-carbon double bonds per molecule. Specific examples of such unsaturated group-containing compounds (a2) include, for example, 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1,1-(bisacryloyloxymethyl)ethyl isocyanate; acryloyl monoisocyanate compounds obtained by the reaction of a diisocyanate compound or polyisocyanate compound with hydroxyethyl (meth)acrylate; acryloyl monoisocyanate compounds obtained by the reaction of a diisocyanate compound or polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate; glycidyl (meth)acrylate; (meth)acrylic acid, 2-(1-aziridinyl)ethyl (meth)acrylate, 2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline, etc.

[0126] The above unsaturated group-containing compound (a2) is used in a ratio of preferably 50 mol% or more, particularly preferably 60 mol% or more, and even more preferably 70 mol% or more, relative to the number of moles of the functional group-containing monomer of the above acrylic copolymer (a1). Furthermore, the above unsaturated group-containing compound (a2) is used in a ratio of preferably 95 mol% or less, particularly preferably 93 mol% or less, and even more preferably 90 mol% or less, relative to the number of moles of the functional group-containing monomer of the above acrylic copolymer (a1).

[0127] In the reaction between the acrylic copolymer (a1) and the unsaturated group-containing compound (a2), the reaction temperature, pressure, solvent, time, presence or absence of a catalyst, and type of catalyst can be appropriately selected depending on the combination of functional groups present in the acrylic copolymer (a1) and the functional groups present in the unsaturated group-containing compound (a2). As a result, the functional groups present in the acrylic copolymer (a1) react with the functional groups in the unsaturated group-containing compound (a2), introducing unsaturated groups into the side chains of the acrylic copolymer (a1), and yielding an active energy ray-curable polymer (A).

[0128] The weight-average molecular weight (Mw) of the activated energy ray-curable polymer (A) obtained in this manner is preferably 10,000 or more, particularly preferably 100,000 or more, and even more preferably 150,000 or more. Furthermore, the weight-average molecular weight (Mw) is preferably 1,500,000 or less, particularly preferably 1,250,000 or less, and even more preferably 1,000,000 or less.

[0129] Even if the active energy ray-curable adhesive mainly consists of an active energy ray-curable polymer (A), the active energy ray-curable adhesive may further contain an energy ray-curable monomer and / or oligomer (B).

[0130] As the active energy ray curable monomer and / or oligomer (B), for example, an ester of a polyhydric alcohol and (meth)acrylic acid can be used.

[0131] Examples of such active energy ray curable monomers and / or oligomers (B) include monofunctional acrylic acid esters such as cyclohexyl (meth)acrylate and isobornyl (meth)acrylate, polyfunctional acrylic acid esters such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and dimethylol tricyclodecane di(meth)acrylate, as well as polyester oligo(meth)acrylate and polyurethane oligo(meth)acrylate.

[0132] When an active energy ray-curable polymer (A) is combined with an active energy ray-curable monomer and / or oligomer (B), the content of the active energy ray-curable monomer and / or oligomer (B) in the active energy ray-curable adhesive is preferably more than 0 parts by mass, and particularly preferably 60 parts by mass or more, per 100 parts by mass of the active energy ray-curable polymer (A). Furthermore, the content is preferably 250 parts by mass or less, and particularly preferably 200 parts by mass or less, per 100 parts by mass of the active energy ray-curable polymer (A).

[0133] Next, we will explain the case where the active energy ray-curable adhesive mainly consists of a mixture of an active energy ray-noncurable polymer component and a monomer and / or oligomer having at least one active energy ray-curable group.

[0134] As the active energy ray non-curing polymer component, for example, the same component as the acrylic copolymer (a1) described above can be used.

[0135] The monomer and / or oligomer having at least one active energy ray curable group can be the same as component (B) described above. The blending ratio of the active energy ray non-curable polymer component to the monomer and / or oligomer having at least one active energy ray curable group is preferably 1 part by mass or more of the monomer and / or oligomer having at least one active energy ray curable group per 100 parts by mass of the active energy ray non-curable polymer component, and particularly preferably 60 parts by mass or more. Furthermore, the blending ratio is preferably 200 parts by mass or less of the monomer and / or oligomer having at least one active energy ray curable group per 100 parts by mass of the active energy ray non-curable polymer component, and particularly preferably 160 parts by mass or less.

[0136] (2) Non-reactive energy ray curable adhesive If the interfacial ablation layer 12 is an adhesive layer composed of an inactive energy ray curable adhesive, the adhesive may be any of the following: acrylic adhesive, rubber adhesive, silicone adhesive, urethane adhesive, polyester adhesive, polyvinyl ether adhesive, etc. However, from the viewpoint of easily exhibiting the desired adhesive strength, an acrylic adhesive is preferred.

[0137] An example of an acrylic adhesive used as a non-active energy ray curable adhesive is an adhesive containing the active energy ray non-curable polymer component described above. The active energy ray non-curable polymer component can also be the same component as the acrylic copolymer (a1) described above. The non-active energy ray curable adhesive does not contain the active energy ray curable polymer described above, nor the monomers and / or oligomers having at least one active energy ray curable group described above.

[0138] (3) Additives As described above, the interfacial ablation 11 in this embodiment preferably contains at least one additive, such as an ultraviolet absorber and a photopolymerization initiator, from the viewpoint of facilitating interfacial ablation.

[0139] (3-1) UV absorbers The type of UV absorber in this embodiment is not particularly limited. The UV absorber in this embodiment may be an organic compound or an inorganic compound, but an organic compound is preferred from the viewpoint of easily generating good interfacial ablation.

[0140] When the UV absorber is an organic compound, preferred examples of such UV absorbers include hydroxyphenyltriazine-based UV absorbers, benzophenone-based UV absorbers, benzotriazole-based UV absorbers, benzoate-based UV absorbers, benzoxazinon-based UV absorbers, phenylsalicylate-based UV absorbers, cyanoacrylate-based UV absorbers, nickel complex salt-based UV absorbers, hydroquinone-based UV absorbers, salicylic acid-based UV absorbers, malonic acid ester-based UV absorbers, and oxalic acid-based UV absorbers. These may be used individually or in combination of two or more.

[0141] Among the UV absorbers mentioned above, it is preferable to use at least one of the following: a hydroxyphenyltriazine-based UV absorber, a benzophenone-based UV absorber, and a benzotriazole-based UV absorber, from the viewpoint of having good absorption at the third harmonic of YAG (355 nm) and readily generating good interfacial ablation. In particular, it is preferable to use a hydroxyphenyltriazine-based UV absorber.

[0142] The above hydroxyphenyltriazine-based UV absorbers include 2-[4-(octyl-2-methylethanolate)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)]-1,3,5-triazine, 2-[4-(2-hydroxy-3-dodecyloxypropyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-(2-hydroxy-3-tridecyloxypropyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine, Examples include 2-[4-(2-hydroxy-3-(2'-ethyl)hexyloxy]-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3-5-triazine, 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, and tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine. These may be used individually or in combination of two or more.

[0143] Among these, it is preferable to use at least one of tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine, 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, 2-[4-(2-hydroxy-3-dodecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2-[4-(2-hydroxy-3-tridecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine].

[0144] Furthermore, if the UV absorber is an organic compound, it is preferable that the UV absorber has one or more heterocycles as a characteristic of its chemical structure. In this case, the number of heterocycles is preferably four or less, and particularly preferably one.

[0145] Furthermore, as another characteristic of the chemical structure, it is preferable that the ultraviolet absorber in this embodiment has at least one of a carbocyclic ring and a heterocyclic ring, and that all of the carbocyclic rings and heterocyclic rings in the ultraviolet absorber are monocyclic rings.

[0146] As a further characteristic of the chemical structure, the ultraviolet absorber in this embodiment is preferably a compound having multiple aromatic rings. In this case, the number of aromatic rings is preferably two or more. Furthermore, the number of aromatic rings is preferably six or less, and particularly preferably three or less.

[0147] In the chemical structural characteristics described above, each heterocycle preferably has at least one element other than carbon selected from nitrogen, oxygen, phosphorus, sulfur, silicon, and selenium, and is particularly preferably at least one selected from nitrogen, oxygen, phosphorus, and sulfur. Furthermore, there is no particular limit to the number of atoms constituting the ring structure of the heterocycle; for example, it is preferably 3 to 9, and particularly preferably 5 to 6. Specific examples of preferred heterocycles include triazine, benzotriazole, thiophene, pyrrole, imidazole, pyridine, and pyrazine.

[0148] Furthermore, regarding the chemical structural characteristics described above, preferred examples of aromatic rings include benzene, naphthalene, anthracene, biphenyl, and triphenyl.

[0149] An example of an ultraviolet absorber having the chemical structural characteristics described above is tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine).

[0150] In this embodiment, when the interfacial ablation layer 12 contains an ultraviolet absorber, the content of the ultraviolet absorber in the interfacial ablation layer 12 is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more. A content of 1% by mass or more of ultraviolet absorber allows the interfacial ablation layer 12 to efficiently absorb laser light, thereby facilitating good interfacial ablation. Furthermore, the content of the ultraviolet absorber in the interfacial ablation layer 12 is preferably 75% by mass or less, more preferably 40% by mass or less, and even more preferably 25% by mass or less. A content of 75% by mass or less of ultraviolet absorber results in an appropriate viscosity for the material used to form the interfacial ablation layer 12, making it easier to ensure good film formation.

[0151] Furthermore, if the interfacial ablation layer 12 in this embodiment is formed from an adhesive composition described later, the ultraviolet absorber may be incorporated into this adhesive composition. In that case, the amount of ultraviolet absorber incorporated into the adhesive composition is preferably 1% by mass or more, particularly preferably 3% by mass or more, and even more preferably 5% by mass or more. By incorporating 1% by mass or more of ultraviolet absorber, the interfacial ablation layer 12 efficiently absorbs laser light, thereby facilitating good interfacial ablation. Furthermore, by incorporating 75% by mass or less of ultraviolet absorber into the adhesive composition, the resulting adhesive is more likely to exhibit the desired adhesive strength.

[0152] (3-2) Photopolymerization initiator The photopolymerization initiator in this embodiment is not particularly limited. When the interfacial ablation layer 12 is an adhesive layer composed of an active energy ray curable adhesive, it is preferable that the interfacial ablation layer 12 contains a photopolymerization initiator. In this case, efficient interfacial ablation is more easily achieved, and the interfacial ablation layer 12 hardens efficiently.

[0153] Examples of photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, and 1-hydroxycyclo Hexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-phenyl)butan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxymethylpropanone, ethanone, 1-[9-ethyl-6-(2-methylbenzo [Iyl]-9H-carbazole-3-yl]-,1-(O-acetyloxime), benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiary-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone Examples include oxantone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, oligo[2-hydroxy-2-methyl-1[4-(1-methylvinyl)phenyl]propanone], 2-benzyl-2-(dimethylamino)-4'-morpholinobylophenone, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. These may be used individually or in combination of two or more.

[0154] Among the photopolymerization initiators mentioned above, it is preferable to use at least one of the following: 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one, ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(0-acetyloxime), 2-benzyl-2-(dimethylamino)-4'-morpholinobylophenone, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and 2,2-dimethoxy-1,2-diphenylethane-1-one.

[0155] In this embodiment, when the interfacial ablation layer 12 contains a photopolymerization initiator, the content of the photopolymerization initiator in the interfacial ablation layer 12 is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more. A photopolymerization initiator content of 1% by mass or more allows the interfacial ablation layer 12 to efficiently absorb laser light, thereby facilitating good interfacial ablation. Furthermore, the photopolymerization initiator content in the interfacial ablation layer 12 is preferably 75% by mass or less, more preferably 40% by mass or less, and even more preferably 25% by mass or less. A photopolymerization initiator content of 75% by mass or less results in an appropriate viscosity for the material used to form the interfacial ablation layer 12, making it easier to ensure good film formation.

[0156] Furthermore, if the interfacial ablation layer 12 in this embodiment is formed from an adhesive composition described later, the photopolymerization initiator may be incorporated into this adhesive composition. In that case, the amount of photopolymerization initiator in the adhesive composition is preferably 1% by mass or more, particularly preferably 3% by mass or more, and even more preferably 5% by mass or more. By incorporating 1% by mass or more of the photopolymerization initiator, the interfacial ablation layer 12 efficiently absorbs laser light, thereby facilitating good interfacial ablation. Furthermore, by incorporating 75% by mass or less of the photopolymerization initiator in the adhesive composition, the amount of photopolymerization initiator is preferably 75% by mass or less, particularly preferably 40% by mass or less, and even more preferably 25% by mass or less. By incorporating 75% by mass or less of the photopolymerization initiator, the resulting adhesive is more likely to exhibit the desired adhesive strength.

[0157] (4) Other ingredients The adhesive constituting the interfacial ablation layer 12 according to this embodiment may contain other components as appropriate. Examples of other components include crosslinking agents, active energy ray non-curing polymer components, or oligomer components.

[0158] The use of a crosslinking agent is preferable from the viewpoint of easily adjusting the storage modulus of the interfacial ablation layer 12 to a desired range. As the crosslinking agent, a polyfunctional compound that has reactivity with the functional groups of the active energy ray curable polymer (A) or acrylic copolymer (a1) can be used. Examples of such polyfunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts, and reactive phenolic resins.

[0159] The amount of crosslinking agent is preferably 0.001 parts by mass or more, particularly preferably 0.1 parts by mass or more, and more preferably 0.2 parts by mass or more, per 100 parts by mass of the main component. Furthermore, the amount of crosslinking agent is preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of the main component. The above-mentioned "main component" refers to the above-mentioned active energy ray curable polymer (A) when the interfacial ablation layer 12 is composed of an active energy ray curable adhesive, and refers to the above-mentioned acrylic copolymer (a1) when the interfacial ablation layer 12 is composed of a non-active energy ray curable adhesive.

[0160] Examples of the active energy ray non-curing polymer or oligomer components mentioned above include polyacrylic acid esters, polyesters, polyurethanes, polycarbonates, and polyolefins, with polymers or oligomers having a weight-average molecular weight (Mw) of 3,000 to 2,500,000 being preferred. By incorporating these components, tackiness, release properties, adhesion to other layers, and storage stability can be improved.

[0161] (5) Thickness of the interfacial ablation layer In this embodiment, the thickness of the interface ablation layer 12 is preferably 3 μm or more, particularly preferably 20 μm or more, and even more preferably 25 μm or more. Furthermore, the thickness of the interface ablation layer 12 is preferably 100 μm or less, particularly preferably 50 μm or less, and even more preferably 40 μm or less. Having the thickness of the interface ablation layer 12 within the above range makes it easier to achieve both the retention of workpiece pieces on the interface ablation layer 12 and the separation of workpiece pieces by interface ablation.

[0162] 3. Base material The base material 13 in this embodiment is not particularly limited in terms of its composition or physical properties. From the viewpoint of making it easier for the work handling sheet 1 to perform the desired function, it is preferable that the base material 13 be made of a resin. When the base material 13 is made of a resin, examples of such resins include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resins such as polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, ethylene-norbornene copolymer, and norbornene resin; ethylene-vinyl acetate copolymer; ethylene copolymer resins such as ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate methyl copolymer, and other ethylene-(meth)acrylic acid ester copolymers; polyvinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer; (meth)acrylic acid ester copolymer; polyurethane; polyimide; polystyrene; polycarbonate; and fluororesin. Furthermore, the resin constituting the base material 13 may be a crosslinked version of the above-mentioned resins or a modified version such as an ionomer of the above-mentioned resins. Furthermore, the base material 13 may be a single-layer film made of the resin described above, or it may be a laminated film formed by laminating multiple such films. In this laminated film, the materials constituting each layer may be of the same type or different types.

[0163] In this embodiment, the surface of the substrate 13 may be subjected to surface treatment such as oxidation or embossing, or primer treatment, in order to improve adhesion to the interfacial ablation layer 12. Examples of oxidation methods include corona discharge treatment, plasma discharge treatment, chromium oxidation (wet), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment. Examples of embossing methods include sandblasting and thermal spraying.

[0164] In this embodiment, the substrate 13 may contain various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, and fillers. Furthermore, if the interfacial ablation layer 12 contains a material that hardens with active energy rays, it is preferable that the substrate 13 is permeable to active energy rays.

[0165] The method for manufacturing the base material 13 in this embodiment is not particularly limited as long as it is manufactured from a resin. For example, it can be manufactured by molding the resin into a sheet using a melt extrusion method such as a T-die method or a circular die method; a calendering method; a solution method such as a dry method or a wet method.

[0166] In this embodiment, the thickness of the base material 13 is preferably 10 μm or more, particularly preferably 30 μm or more, and even more preferably 50 μm or more. Furthermore, the thickness of the base material 13 is preferably 500 μm or less, more preferably 300 μm or less, particularly preferably 200 μm or less, even more preferably 150 μm or less, and most preferably 100 μm or less. When the thickness of the base material 13 is within the above range, the work handling sheet 1 will have a predetermined balance of rigidity and flexibility, making it easier to handle small workpieces well.

[0167] 4. Release sheet In this embodiment, if the interface ablation layer 12 includes an adhesive as one of its constituent components, a release sheet may be laminated on the surface of the interface ablation layer 12 opposite to the substrate 13 for the purpose of protecting that surface until it is attached to the workpiece.

[0168] The composition of the release sheet described above is arbitrary, and an example is a plastic film that has been treated with a release agent. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, silicone-based, fluorine-based, and long-chain alkyl-based agents can be used, and among these, silicone-based agents are preferred because they are inexpensive and provide stable performance.

[0169] There are no particular restrictions on the thickness of the release sheet mentioned above; for example, it may be between 20 μm and 250 μm.

[0170] 5. Method for manufacturing a work handling sheet The method for manufacturing the work handling sheet 1 according to this embodiment is not particularly limited. For example, a work handling sheet 1 may be obtained by first obtaining a laminate formed by forming an adhesive layer 11 on a release sheet and a laminate formed by forming an interface ablation layer 12 on a substrate 13, and then bonding the adhesive layer 11 and the interface ablation layer 12 together.

[0171] The adhesive layer 11 described above can be formed by known methods. For example, a coating solution containing an adhesive composition for forming the adhesive layer 11, and optionally a solvent or dispersion medium, can be prepared. Then, the coating solution is applied to the release surface of the release sheet (hereinafter sometimes referred to as the "release surface"). Subsequently, the adhesive layer 11 can be formed by drying the resulting coating film. Note that another release sheet may be applied to the exposed surface of the adhesive layer 11 until it is laminated onto the interfacial ablation layer 12.

[0172] The interfacial ablation layer 12 can also be formed by known methods. If an adhesive is included as one of the components constituting the interfacial ablation layer 12, for example, a coating solution containing an adhesive composition for forming the interfacial ablation layer 12, and optionally a solvent or dispersion medium, is prepared. The coating solution is then applied to the release surface of the release sheet. Subsequently, the resulting coating film is dried to form the interfacial ablation layer 12, and then the substrate 11 is attached to the surface exposed to the interfacial ablation layer 12. Alternatively, the interfacial ablation layer 12 may be formed directly on the substrate 11.

[0173] The coating solution described above can be applied by known methods, such as bar coating, knife coating, roll coating, blade coating, die coating, gravure coating, etc. The properties of the coating solution are not particularly limited as long as it can be applied, and it may contain components for forming the adhesive layer 11 and the interfacial ablation layer 12 as a solute or as a dispersed phase. Furthermore, if the adhesive layer 11 is formed on a release sheet, the release sheet may be peeled off as a process material, or it may protect the adhesive layer 11 until it is attached to the adherend.

[0174] If the adhesive composition and tacky composition described above contain the aforementioned crosslinking agent, it is preferable to promote the crosslinking reaction between the polymer component in the coating film and the crosslinking agent by changing the drying conditions (temperature, time, etc.) or by separately providing a heat treatment, thereby forming a crosslinked structure at a desired density within the adhesive layer 11 and the interfacial ablation layer 12. Furthermore, in order to allow the above-mentioned crosslinking reaction to proceed sufficiently, curing may be performed after the completion of the work handling sheet 1, for example, by leaving it undisturbed in an environment of 23°C and 50% relative humidity for several days.

[0175] 6. How to use the work handling sheet The work handling sheet 1 according to this embodiment can be suitably used for handling workpieces. One example of how to use the work handling sheet 1 according to this embodiment is to hold a workpiece on the side of the adhesive layer 11 opposite to the interfacial ablation layer 12, and then, while the workpiece is held on the side of the adhesive layer 11 opposite to the interfacial ablation layer 12, the workpiece is fragmented together with the adhesive layer 11 to obtain a plurality of laminates consisting of small pieces of the workpiece and small pieces of the adhesive layer 11. Then, at least one of these laminates is selectively separated from the interfacial ablation layer 12 by interfacial ablation locally generated in the interfacial ablation layer 12.

[0176] Alternatively, instead of separating the workpiece on the work handling sheet 1 as described above, pre-separated workpiece pieces may be attached to the adhesive layer 11 side of the work handling sheet 1. In this case, only the adhesive layer 11 will be separated to match the workpiece pieces.

[0177] As mentioned above, examples of the workpieces include semiconductor wafers, semiconductor packages, and glass plates. The workpiece handling sheet 1 according to this embodiment makes it possible to handle even extremely thin workpieces without damaging them. For example, the workpiece handling sheet 1 according to this embodiment can suitably handle workpieces with a thickness of 150 μm or less, particularly workpieces with a thickness of 100 μm or less, and even workpieces with a thickness of 50 μm or less. Workpieces with thicknesses exceeding these ranges can also be handled. Furthermore, the lower limit of the thickness is not particularly limited, but may be 150 μm or more, particularly 100 μm or more, and even 50 μm or more.

[0178] Below, a preferred method for using the work handling sheet 1 according to this embodiment, specifically a method for manufacturing a semiconductor device, will be described with reference to Figure 3. This manufacturing method includes, for example, a piece-forming step of obtaining a plurality of laminates consisting of small pieces of the work and small pieces of the adhesive layer 11 by piece-forming the work together with the adhesive layer 11 while holding the work on the adhesive layer 11 side of the work handling sheet 1 according to this embodiment; an irradiation step of irradiating a laser beam to a position in the interface ablation layer 12 where at least one of the laminates is held, thereby causing interface ablation at the irradiated position in the interface ablation layer 12; and a pickup step of picking up the laminate located at the position where interface ablation has occurred from the work handling sheet 1.

[0179] In the above-described piece-forming process, first, the workpiece 2 is attached to the adhesive layer 11 of the work handling sheet 1, as shown in Figure 3(a). Although not shown, the ring frame may also be attached to a position on the work handling sheet 1 where the workpiece 2 is not laminated. In particular, in the work handling sheet 1 shown, the adhesive layer 11 is smaller in size than the interface ablation layer 12, and as a result the interface ablation layer 12 is exposed. The ring frame can be attached to this exposed position. If the interface ablation layer 12 is an adhesive layer, the ring frame may be attached directly to the interface ablation layer 12, and if it is not an adhesive layer, the ring frame may be attached via a separate adhesive layer. Even when using the work handling sheet 1 shown in Figure 1 (where the adhesive layer 11 and the interface ablation layer 12 are substantially the same in plan view), the ring frame can still be attached.

[0180] Next, as shown in Figure 3(b), the workpiece 2 is divided together with the adhesive layer 11. Any known method can be used for this division, and dicing using a dicing blade is particularly preferred. This dicing can also be carried out by a known method. Through this division, the workpiece 2 is divided into small pieces 2', and the adhesive layer 11 is divided into film-like adhesive pieces 11'.

[0181] Subsequently, as shown in Figure 3(c), in the irradiation step, the interface ablation layer 12 is irradiated with laser light 3 to cause interface ablation. This irradiation may be performed simultaneously on multiple locations where the laminate (a laminate consisting of workpiece pieces 2' and film-like adhesive 11') exists, but from the viewpoint of facilitating selective separation of the laminate, it is preferable to irradiate only the locations where the laminate to be separated exists.

[0182] Upon irradiation with laser light 5, as shown in the figure, the region of the interface ablation layer 12 closest to the substrate 13 becomes a reaction region 12' due to the evaporation or volatilization of the components constituting that region. The gas generated by the evaporation or volatilization then accumulates between the substrate 13 and the reaction region 12', forming a blister 12''. The formation of this blister 12'' causes local deformation of the interface ablation layer 12, resulting in partial separation at the interface between the laminate (a laminate consisting of workpiece pieces 2' and film-like adhesive 11') and the interface ablation layer 12. This then facilitates the pickup of the laminate in the pickup process described later. The irradiation conditions for laser light 3 are not limited as long as they can cause interface ablation. Furthermore, known laser irradiation devices can be used for irradiation.

[0183] Finally, as shown in Figure 3(d), in the pickup process, the laminate located at the position where interfacial ablation occurred is picked up from the work handling sheet 1 using an adsorption collet 4 or the like. As described above, since there is a trigger for separation between the laminate and the interfacial ablation layer 12, the laminate can be easily picked up. Generally, when picking up, the back surface of the work handling sheet 1 is sometimes pushed up using a needle or the like, but with the work handling sheet 1 according to this embodiment, since there is already a trigger for separation, it can be easily picked up without such pushing up.

[0184] Furthermore, at any stage of the irradiation process or the pickup process, the work handling sheet 1 may be expanded to separate the laminates from each other.

[0185] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit it. Accordingly, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0186] For example, other layers may be laminated between the interface ablation layer 12 and the substrate 13 in the work handling sheet 1 according to this embodiment, or on the surface of the substrate 13 opposite to the interface ablation layer 12. A specific example of such other layer is an adhesive layer. In this case, the separation process described above can be performed with the side with the adhesive layer attached to a support base (a transparent substrate such as a glass plate). [Examples]

[0187] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0188] [Preparation example 1] (Adhesive composition 1) An acrylic polymer was obtained by polymerizing 80 parts by mass of 2-ethylhexyl acrylate and 20 parts by mass of 2-hydroxyethyl acrylate using a solution polymerization method. The weight-average molecular weight (Mw) of this acrylic polymer was measured by the method described later and was found to be 600,000.

[0189] 90.1 parts by mass (on a solid content basis, the same applies hereinafter) of the acrylic polymer obtained above, 0.9 parts by mass of trimethylolpropane-modified tolylene diisocyanate (manufactured by Tosoh Corporation, trade name "Coronate L") as a crosslinking agent, and 9 parts by mass of tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine (hydroxyphenyltriazine-based ultraviolet absorber, manufactured by BASF, product name "Tinuvin 477") as an additive were mixed in a solvent to obtain a coating solution for an adhesive composition. This adhesive composition is referred to as "Adhesive Composition 1".

[0190] The weight-average molecular weight (Mw) of the above acrylic polymer is the weight-average molecular weight in terms of polystyrene, measured using gel permeation chromatography (GPC) under the following conditions (GPC measurement). <Measurement conditions> • GPC measuring device: Tosoh Corporation, HLC-8320 • GPC column (passes through in the following order): Manufactured by Tosoh Corporation TSK Gel Super H-H TSK gel superHM-H TSK Gel Super H2000 • Measurement solvent: tetrahydrofuran ·Measurement temperature: 40℃

[0191] [Preparation example 2] (Adhesive composition 2) 80 parts by mass of 2-ethylhexyl acrylate and 20 parts by mass of 2-hydroxyethyl acrylate were polymerized by solution polymerization to obtain a (meth)acrylic acid ester polymer. Furthermore, by reacting 2-methacryloyloxyethyl isocyanate (MOI) in an amount equivalent to 80 mol% of the 2-hydroxyethyl acrylate constituting the (meth)acrylic acid ester polymer, an (meth)acrylic acid ester polymer (active energy ray curable polymer) was obtained in which active energy ray curable groups were introduced into the side chains. The weight-average molecular weight of this active energy ray curable polymer was measured by the method described above and was found to be 1 million.

[0192] 81.6 parts by mass of the active energy ray curable polymer obtained above, 2.1 parts by mass of trimethylolpropane-modified tolylene diisocyanate (manufactured by Tosoh Corporation, trade name "Coronate L") as a crosslinking agent, and 16.3 parts by mass of 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one (photopolymerization initiator, manufactured by IGM Resins, product name "Omnirad379") as an additive were mixed in a solvent to obtain a coating solution for an adhesive composition. This adhesive composition is referred to as "Adhesive Composition 2".

[0193] [Preparation example 3] (Adhesive composition 3) 90.1 parts by mass of an active energy ray-curable polymer prepared in the same manner as in Preparation Example 2, 0.8 parts by mass of trimethylolpropane-modified tolylene diisocyanate (manufactured by Tosoh Corporation, trade name "Coronate L") as a crosslinking agent, and 9.0 parts by mass of bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (photopolymerization initiator, manufactured by IGM Resins, product name "Omnirad819") as an additive were mixed in a solvent to obtain a coating solution for an adhesive composition. This adhesive composition is referred to as "Adhesive Composition 3".

[0194] [Preparation Example 4] (Adhesive Composition 1) 84 parts by mass of n-butyl acrylate, 8 parts by mass of methyl methacrylate, 3 parts by mass of acrylic acid, and 5 parts by mass of 2-hydroxyethyl acrylate were polymerized by solution polymerization to obtain an acrylic polymer (this acrylic polymer will be referred to as "acrylic polymer (1)"). The weight-average molecular weight (Mw) of this acrylic polymer (1) was measured by the method described above and was found to be 800,000.

[0195] The above-mentioned acrylic polymer (1) is used in a mixture of 18 parts by mass, 40 parts by mass of o-cresol novolac epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product name "EOCN-102S", epoxy equivalent 205-217 g / eq, softening point 55-77°C), 10 parts by mass of trishydroxyphenylmethane epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product name "EPPN-502H", epoxy equivalent 167 g / eq, softening point 54°C, molecular weight 1200), 6 parts by mass of liquid bisphenol F epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name "YL983U", epoxy equivalent 165-175 g / eq), and o-cresol novolac resin (manufactured by DIC Corporation, product name "Phenolite KA-1160", hydroxyl group equivalent 117 g / eq) as a thermosetting agent. 24 parts by mass of q (softening point 80°C, n: 6-7 in general formula (1)), 0.3 parts by mass of 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemicals, product name "Curesol 2PHZ-PW", melting point 137-147°C) as a curing accelerator, 1.0 part by mass of an oligomer-type silane coupling agent having epoxy, methyl, and methoxy groups (manufactured by Shin-Etsu Silicone, product name "X-41-1056", epoxy equivalent 280 g / eq) as a coupling agent, and 0.7 parts by mass of a trimethylolpropane tolylene diisocyanate trimer adduct (manufactured by Toyo Chem, product name "BHS8515") as a crosslinking agent were mixed in methyl ethyl ketone as a solvent at 23°C to obtain a coating solution of an adhesive composition with a solid content of 50% by mass. This adhesive composition is referred to as "Adhesive Composition 1".

[0196] [Preparation Example 5] (Adhesive Composition 2) 55 parts by mass of n-butyl acrylate, 10 parts by mass of methyl methacrylate, 20 parts by mass of glycidyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate were polymerized by solution polymerization to obtain an acrylic polymer (this acrylic polymer will be referred to as "acrylic polymer (2)"). The weight-average molecular weight (Mw) of this acrylic polymer (2) was measured by the method described above and was found to be 800,000.

[0197] An adhesive coating solution was obtained in the same manner as in Preparation Example 4, except that the acrylic polymer (2) prepared as described above was used instead of the acrylic polymer (1) mentioned above. This adhesive composition is referred to as "Adhesive Composition 2".

[0198] [Preparation Example 6] (Adhesive Composition 3) Except for changing the amount of the aforementioned acrylic polymer (1) to 17 parts by mass and adding 1 part by mass of alkylaralkyl-modified silicone oil (manufactured by Momentive Performance Materials Japan, product name "XF42-334") as a general-purpose additive, a coating solution of the adhesive composition was obtained in the same manner as in Preparation Example 4. This adhesive composition is referred to as "Adhesive Composition 3".

[0199] [Preparation Example 7] (Adhesive Composition 4) Except for changing the amount of the aforementioned acrylic polymer (1) to 15 parts by mass, adding 2.9 parts by mass of dicyclopentanyl diacrylate (manufactured by Nippon Kayaku Co., Ltd., product name "Kayarad R-684") as an active energy ray curable resin, and adding 0.1 parts by mass of 2,2-dimethoxy-1,2-diphenylethane-1-one (manufactured by IGM Resins, product name "Omnirad 651") as a photopolymerization initiator, a coating solution for the adhesive composition was obtained in the same manner as in Preparation Example 4. This adhesive composition is referred to as "Adhesive Composition 4".

[0200] [Preparation Example 8] (Adhesive Composition 5) Except for changing the amount of the aforementioned acrylic polymer (1) to 8 parts by mass, adding 9.7 parts by mass of dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., product name "Kayarad DPHA") as an active energy ray curable resin, and adding 0.3 parts by mass of 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by IGM Resins, product name "Omnirad 184") as a photopolymerization initiator, a coating solution for the adhesive composition was obtained in the same manner as in Preparation Example 4. This adhesive composition is referred to as "Adhesive Composition 5".

[0201] [Example 1] (1) Formation of an interfacial ablation layer (adhesive layer) A release sheet (Lintec Corporation, product name "SP-PET381031") (referred to as "Release Sheet A"), which has a silicone-based release agent layer formed on one side of a 38 μm thick polyethylene terephthalate film, was coated with the adhesive composition 1 obtained in Preparation Example 1, and the resulting coating film was dried by heating. This resulted in a laminate in which a 5 μm thick interfacial ablation layer (adhesive layer) formed by the drying of the coating film and Release Sheet A were laminated together.

[0202] (2) Formation of adhesive layer A release sheet (Lintec Corporation, product name "SP-PET381031") (referred to as "Release Sheet B"), which has a silicone-based release agent layer formed on one side of a 38 μm thick polyethylene terephthalate film, was coated with the adhesive composition 1 obtained in Preparation Example 4 and heated and dried at 100°C for 1 minute to form an adhesive layer with a thickness of 20 μm.

[0203] Next, the release surface of a release sheet (Lintec Corporation, product name "SP-PET382150"), which has a silicone-based release agent layer formed on one side of a 38 μm thick polyethylene terephthalate film (referred to as "Release Sheet C"), was bonded to the side of the formed adhesive layer opposite to the release sheet B. This resulted in a laminate in which release sheet B, the adhesive layer, and release sheet C were sequentially laminated.

[0204] (3) Preparation of work handling sheet The side of the laminate obtained in step (1) above, facing the interface ablation layer, was bonded to one side (glossy side) of an 80 μm thick ethylene-methacrylic acid copolymer (EMMA) film used as a substrate. Then, the release sheet A was peeled off, exposing the interface ablation layer.

[0205] Meanwhile, the release sheet C was peeled off from the laminate obtained in step (2) above, thereby exposing the adhesive layer. Then, the exposed surface of the adhesive layer and the exposed surface of the interface ablation layer exposed as described above were bonded together to obtain a work handling sheet in which the release sheet B, the adhesive layer, the interface ablation layer, and the substrate were laminated in that order.

[0206] [Examples 2-7] A work handling sheet was obtained in the same manner as in Example 1, except that the adhesive composition and bonding agent composition used were changed as shown in Table 1.

[0207] [Comparative Example 1] In the same manner as in step (2) of Example 1, a laminate was obtained in which a release sheet B, an adhesive layer, and a release sheet C were laminated in order. Then, the release sheet C was peeled off from the laminate, and one side (glossy side) of an 80 μm thick ethylene methacrylic acid copolymer (EMMA) film was bonded to the exposed surface of the exposed adhesive layer, thereby obtaining a work handling sheet in which a release sheet B, an adhesive layer, and a substrate were laminated in order.

[0208] [Test Example 1] (1) Dicing The release sheet B was peeled off from the work handling sheets manufactured in the examples and comparative examples. The exposed adhesive layer was then applied to the polished surface of a silicon wafer (200 mm in diameter, 50 μm thick) with one side being a #2000 polished surface, using a tape bonding device (Lintec Corporation, product name "Adwill RAD2500") while heating to 60°C. Simultaneously with this application, a ring frame, which is a dicing jig, was applied to the outer periphery of the silicon wafer on the exposed adhesive layer surface, via a jig adhesive layer cut to the size of the ring frame.

[0209] Next, the silicon wafer was diced together with the adhesive layer using a dicing device (DISCO Corporation, product name "DFD6361"). This resulted in obtaining multiple silicon chips with film-like adhesive, each chip consisting of a silicon chip formed from the silicon wafer and a film-like adhesive formed from the adhesive layer, each chipped to the same size.

[0210] The dicing process described above was performed so that the dimensions of the film-adhesive-coated silicon chip in plan view were 5 mm x 5 mm. The dicing blade was moved at a speed of 30 mm / s and rotated at 30,000 rpm. The dicing blade was used until the remaining thickness of the work handling sheet was 40 μm. The dicing blade used was a product named "Z05-SD2000-D1-90 CC" manufactured by Disco Corporation.

[0211] (2) Expanding and laser light irradiation Next, a work handling sheet consisting of multiple film-like adhesive-coated silicon chips was placed in a pick-up die bonding device (manufactured by Canon Machinery, product name "BESTEM D-510"), and the work handling sheet was expanded to an expansion amount of 4 mm.

[0212] Then, while maintaining the expanded state, a laser beam irradiation device (Keyence Corporation, product name "MD-U1000C") was used to irradiate the interface ablation layer with laser light through the substrate. This irradiation was performed at each location where a single film-like adhesive-coated silicon chip was stacked. This irradiation was carried out sequentially, and a total of 100 film-like adhesive-coated silicon chips were irradiated.

[0213] Specifically, the irradiation conditions involved irradiating the center of the chip with a 25 μm diameter laser spot at a frequency of 40 kHz, a scan speed of 500 mm / s, and an irradiation dose of 50 μJ / shot.

[0214] For Comparative Example 1, in which the work handling sheet does not have an interfacial ablation layer, laser irradiation was performed under the same settings and conditions as in Examples 1 to 7.

[0215] (3) Pickup and evaluation of film-type adhesive-coated silicon chips While maintaining the expanded state, the film-like adhesive-coated silicon chips located at the laser-irradiated position were picked up one by one using a suction collet. At this time, no pushing was performed from the back of the work handling sheet using a needle or the like.

[0216] The number of film-like adhesive-coated silicone chips that could be picked up was then evaluated based on the following criteria. The results are shown in Table 1. ◎...All 100 items were successfully picked up. ○...The number of items that were successfully picked up was between 80 and 100. △...The number of items that were successfully picked up was between 50 and 80. ×...The number of items picked up was less than 50, or, during the picking process, chips other than the intended ones became detached.

[0217] Furthermore, for the cases where the above evaluation was "◎", "〇", and "△", the presence or absence of adhesive residue was visually checked at the location where the film-like adhesive-coated silicone chip was removed from the work handling sheet after pickup, and the adhesive residue was evaluated based on the following criteria. The results are also shown in Table 1. ○...No residue from the adhesive layer was found. ×...We were able to confirm the presence of residue in the adhesive layer.

[0218] [Table 1]

[0219] As is clear from Table 1, the work handling sheets manufactured in the examples successfully produced film-type adhesive-coated silicon chips. [Industrial applicability]

[0220] The work handling sheet of the present invention can be suitably used in the manufacture of semiconductor devices and the like. [Explanation of symbols]

[0221] 1…Work Handling Sheet 11…Adhesive layer 11'...Film-type adhesive 12…Interfacial ablation layer 12'...Reaction region 12''...blister 13...Base material 2…Work 2'...Workpiece 3… Laser light 4… Adhesive Collet

Claims

1. Substrate and An interface ablation layer is laminated on one side of the substrate and is capable of interface ablation by irradiation with laser light, An adhesive layer, consisting of a curable film-like adhesive, is laminated on the side of the interface ablation layer opposite to the substrate. Equipped with, The substrate is a single-layer film made of resin, or a laminated film formed by stacking multiple such films. A work handling sheet characterized by the following features.

2. The work handling sheet according to claim 1, characterized in that the interface ablation layer is an adhesive layer.

3. The work handling sheet according to claim 1 or 2, characterized in that the interfacial ablation layer contains at least one additive, which is an ultraviolet absorber and a photopolymerization initiator.

4. The work handling sheet according to any one of claims 1 to 3, characterized in that the laser light has a wavelength in the ultraviolet region.

5. The work handling sheet according to any one of claims 1 to 4, characterized in that when interfacial ablation is caused in the interfacial ablation layer, a blister is formed at the location where the interfacial ablation occurs.

6. A work handling sheet according to any one of claims 1 to 5, characterized in that, while holding a workpiece on the surface of the adhesive layer opposite to the interface ablation layer, the workpiece is fragmented together with the adhesive layer to obtain a plurality of laminates consisting of small pieces of the workpiece and small pieces of the adhesive layer, and then at least one of these laminates is used to selectively separate from the interface ablation layer by interface ablation locally generated in the interface ablation layer.

7. A piece-forming step to obtain a plurality of laminates consisting of small pieces of the work and small pieces of the adhesive layer by holding a workpiece on the adhesive layer side surface of the work handling sheet according to any one of claims 1 to 6, and piece-forming the workpiece together with the adhesive layer, An irradiation step of irradiating the interface ablation layer with laser light at a position where at least one of the laminates is held, thereby causing interface ablation at the irradiated position in the interface ablation layer, A pickup step in which the laminate located at the position where interface ablation occurred is picked up from the work handling sheet. A method for manufacturing a semiconductor device, characterized by comprising the above.

8. A use of the work handling sheet according to any one of claims 1 to 6 for manufacturing a semiconductor device, The method for manufacturing the aforementioned semiconductor device is: A piece-forming step in which, while holding the workpiece on the adhesive layer side of the workpiece handling sheet, the workpiece is pieced together with the adhesive layer to obtain a plurality of laminates consisting of small pieces of the workpiece and small pieces of the adhesive layer, An irradiation step of irradiating the interface ablation layer with laser light at a position where at least one of the laminates is held, thereby causing interface ablation at the irradiated position in the interface ablation layer, A pickup step in which the laminate located at the position where interface ablation occurred is picked up from the work handling sheet. A use characterized by comprising the following features.

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