TWI898103B - Workpiece processing sheet, method for manufacturing semiconductor device, and use of workpiece processing sheet - Google Patents

Abstract

A workpiece processing sheet 1 comprises: a substrate 13; an interfacial peeling layer 12 deposited on one side of the substrate 13 and capable of undergoing interfacial peeling by laser light irradiation; and an adhesive layer 11 deposited on the surface of the interfacial peeling layer 12 opposite the substrate 13 and composed of a curable film-like adhesive. This workpiece processing sheet 1 can effectively produce small workpiece pieces coated with a film-like adhesive.

Description

Workpiece processing sheet, method for manufacturing semiconductor device, and use of workpiece processing sheet

The present invention relates to a workpiece processing sheet that can be used to handle workpieces such as semiconductor wafers, a method for manufacturing a semiconductor device using the workpiece processing sheet, and use of the workpiece processing sheet.

A semiconductor chip is typically die-bonded to the circuit-forming surface of a substrate using a thin film of adhesive applied to its backside. Subsequently, as needed, one or more semiconductor chips are stacked on top of this semiconductor chip and wire-bonded. The resulting assembly is then sealed with resin to create a semiconductor package. This semiconductor package is then used to manufacture the desired semiconductor device.

Semiconductor chips with a film adhesive on their backside are manufactured, for example, by dicing a semiconductor wafer with a film adhesive on its backside and shearing the film adhesive. A widely used method for dicing a semiconductor wafer into semiconductor chips in this manner is to use a dicing blade to cut the semiconductor wafer along with the film adhesive. In this case, the film adhesive before cutting is used as a die bonding sheet, which is laminated onto a support sheet used to secure the semiconductor wafers during dicing.

After dicing is completed, the semiconductor chip with the cut film adhesive on the back side (semiconductor chip with film adhesive) is pulled off the support sheet and picked up.

For example, Patent Document 1 discloses a dicing and die-bonding sheet (equivalent to the aforementioned die-bonding dicing sheet) comprising a substrate, a wiring embedding layer releasably deposited on the substrate, a heat-resistant insulating film deposited on the wiring embedding layer, and an adhesive layer (equivalent to the aforementioned film-like adhesive) formed on the heat-resistant insulating film. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Publication No. 2007-53240

[Identify the problem the invention is trying to solve]

However, the recent trend toward thinner semiconductor wafers has led to various problems when picking up semiconductor wafers coated with film adhesive. For example, if the film adhesive has excessive adhesion to the underlying layer (such as the substrate), the force required to pull the film adhesive-coated semiconductor wafer off the die-bonding sheet becomes excessive, potentially damaging the semiconductor wafer. Furthermore, if the adhesion is too low, adjacent semiconductor wafers can become detached during pickup, or semiconductor wafers can detach randomly at unexpected stages.

The present invention was developed in light of this practical situation, and its purpose is to provide a workpiece processing sheet that can effectively produce small workpiece pieces coated with a thin film of adhesive. [Means for Solving the Problem]

To achieve the above-mentioned objectives, first, the present invention provides a workpiece processing sheet characterized by comprising: a substrate; an interface peeling layer deposited on one side of the substrate and capable of undergoing interface peeling by irradiation with laser light; and an adhesive layer deposited on the side of the interface peeling layer opposite to the substrate and composed of a curable thin-film adhesive (Invention 1).

The workpiece processing sheet of the aforementioned invention (Invention 1) includes the aforementioned interfacial peeling layer, and thus can generate interfacial peeling in the interfacial peeling layer by irradiating the interfacial peeling layer with laser light, thereby changing the shape of the interfacial peeling layer. Therefore, after the workpiece and the adhesive layer are separated on the workpiece processing sheet to obtain small workpiece pieces with a thin film of adhesive, the generation of the above-mentioned interfacial peeling creates an opportunity for separating the thin film of adhesive (the monomerized adhesive layer) from the interfacial peeling layer, thereby easily separating the small workpiece pieces with the thin film of adhesive.

In the above invention (Invention 1), the interface peeling layer is preferably an adhesive layer (Invention 2).

In the above inventions (Inventions 1 and 2), the interface peeling layer preferably contains at least one additive selected from the group consisting of an ultraviolet absorber and a photopolymerization initiator (Invention 3).

In the above inventions (Inventions 1 to 3), the laser light preferably has a wavelength in the ultraviolet region (Invention 4).

In the above inventions (Inventions 1 to 4), preferably, when interfacial corrosion occurs in the interfacial corrosion layer, blisters are formed at locations where the interfacial corrosion occurs (Invention 5).

Among the above inventions (Inventions 1 to 5), it is preferred that the workpiece and the adhesive layer be integrated together while the workpiece is held on the surface of the adhesive layer opposite to the interface peeling layer, thereby obtaining a plurality of layered integrals consisting of small pieces of the workpiece and small pieces of the adhesive layer, and at least one of the layered integrals be selectively separated from the interface peeling layer by locally generating interface peeling in the interface peeling layer (Invention 6).

Second, the present invention provides a method for manufacturing a semiconductor device, characterized by comprising: a singulation step of singulating the workpiece and the adhesive layer together while the workpiece is held on the surface of the adhesive layer side in the workpiece processing sheet (Inventions 1 to 6), thereby obtaining a plurality of layer stacks composed of small pieces of the workpiece and small pieces of the adhesive layer; an irradiation step of irradiating a position in the interface peeling layer where at least one of the layer stacks is held by laser light, thereby generating interface erosion at the irradiated position in the interface peeling layer; and a picking step of picking up the layer stack at the position where the interface erosion has occurred from the workpiece processing sheet (Invention 7).

Thirdly, the present invention provides a method for manufacturing a semiconductor device using the aforementioned workpiece processing sheet (Inventions 1 to 6), characterized in that the method comprises: a singulation step, wherein the workpiece and the aforementioned adhesive layer are singulated together while the workpiece is held on the surface of the aforementioned adhesive layer in the aforementioned workpiece processing sheet, thereby obtaining a plurality of semiconductor devices made of the aforementioned workpiece. a step of irradiating a portion of the interface peeling layer where at least one of the aforementioned integral layers is retained with laser light, thereby causing interface erosion at the irradiated portion of the interface peeling layer; and a step of picking up the aforementioned integral layer at the portion where the interface erosion has occurred from the workpiece processing sheet (Invention 8). [Effect of the Invention]

The workpiece processing sheet of the present invention can well obtain small workpiece pieces with a thin film adhesive.

[Form used to implement the invention]

The following describes an embodiment of the present invention. Figures 1 and 2 show cross-sectional views of a workpiece processing sheet according to one embodiment. The workpiece processing sheet 1 shown in Figures 1 and 2 comprises: a substrate 13; an interfacial peeling layer 12 deposited on one side of the substrate 13; and an adhesive layer 11 deposited on the side of the interfacial peeling layer 12 opposite the substrate 13.

In the workpiece processing sheet 1 shown in FIG1 , the adhesive layer 11 is drawn with the dimensions of the interface peeling layer 12 and the substrate 13 being identical. In the workpiece processing sheet 1 of this embodiment, the adhesive layer 11 can also be configured so that, when viewed from above, it has approximately the same shape as the interface peeling layer 12 and the substrate 13.

On the other hand, in the workpiece processing sheet 1 shown in FIG2 , the adhesive layer 11 is depicted with its dimensions in the lateral direction of the paper being smaller than the interfacial peeling layer 12 and the substrate 13. In the workpiece processing sheet 1 of this embodiment, the adhesive layer 11 can also be configured so that, when viewed from above, it is smaller than the interfacial peeling layer 12 and the substrate 13.

In the workpiece processing wafer 1 of this embodiment, the interface etch layer 12 is subjected to interface etch by irradiation with laser light. In other words, the interface etch layer 12 is subjected to local interface etch in the region irradiated with the laser light.

In this specification, interfacial erosion refers to the evaporation or volatilization of a portion of the components of the interfacial erosion layer 12 due to the energy of the laser beam. The generated gas accumulates at the interface between the interfacial erosion layer 12 and the substrate 13, creating voids (bubbles).

In the workpiece processing sheet 1 of this embodiment, the aforementioned blistering can deform the shape of the interfacial exfoliation layer 12. This, in turn, creates an excellent opportunity for separation at the interface between the workpiece processing sheet 1 and the attached workpiece small piece (or workpiece). Therefore, even when using extremely thin or brittle workpieces, the workpiece can be effectively separated from the workpiece processing sheet 1 without damaging the workpiece.

In particular, because separation is facilitated by the aforementioned action, it is possible to design the workpiece so that the adhesion between the workpiece and the adhesive layer 11 is high. This can suppress the separation of the workpiece or workpiece fragments at unintended stages, as well as the separation of adjacent workpiece fragments during pickup. Furthermore, because the aforementioned interface corrosion occurs locally at the location irradiated with laser light, selective separation of only the desired workpiece fragments can be effectively performed.

Furthermore, in the workpiece processing sheet 1 of this embodiment, the adhesive layer 11 is composed of a curable film-like adhesive. With a workpiece such as a semiconductor wafer already attached to the adhesive layer 11, the workpiece and the adhesive layer 11 are separated (diced) to obtain workpiece pieces with the film-like adhesive. These pieces are formed by laminating the workpiece pieces formed by singulating the workpiece and the film-like adhesive formed by singulating the adhesive layer 11. The resulting workpiece pieces with the film-like adhesive can then be effectively separated from the workpiece processing sheet 1 by performing interface etching as described above.

In addition, as examples of workpieces that can be operated using the workpiece processing sheet 1 of this embodiment, semiconductor wafers, semiconductor packages, glass plates, etc. can be listed. By dividing these, semiconductor chips, divided semiconductor packages, glass pieces, etc. can be obtained as workpiece pieces.

Furthermore, the laser light that can be used for the workpiece processing sheet 1 of this embodiment is not particularly limited as long as it can produce interface etching. It can be laser light with any wavelength in the ultraviolet region, visible light region, and infrared region, among which laser light with a wavelength in the ultraviolet region is preferred.

1. Adhesive Layer The specific structure and composition of the adhesive layer 11 in this embodiment are not particularly limited, as long as it is composed of a curable film-like adhesive. To facilitate the performance expected of the adhesive layer, the adhesive layer 11 in this embodiment is preferably formed using an adhesive composition containing at least one of a thermosetting component and an active energy ray-curable resin. Furthermore, the adhesive composition preferably includes, in addition to the aforementioned components, at least one of an acrylic polymer, a curing accelerator, an inorganic filler, a coupling agent, a crosslinking agent, and a photopolymerization initiator. These components are described below.

(1) Acrylic polymers The composition of acrylic polymers is not particularly limited. Examples of monomers constituting the acrylic polymers include (meth)acrylic acid alkyl esters, particularly (meth)acrylic acid alkyl esters having an alkyl group with 1 to 18 carbon atoms. Specifically, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and the like are preferably used. These may be used alone or in combination of two or more. In this specification, the term "(meth)acrylate" refers to both acrylate and methacrylate. The same applies to other similar terms.

Examples of monomers constituting the acrylic polymer include carboxyl group-containing monomers and hydroxyl group-containing monomers.

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

Examples of monomers containing a hydroxy group 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. These monomers can be used alone or in combination of two or more.

Examples of other monomers include monomers having a cyclic skeleton and monomers having an epoxy group.

Preferred monomers having a cyclic skeleton include cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isoborneol (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and imide (meth)acrylate. These monomers may be used alone or in combination of two or more.

As the monomer having an epoxy group, glycidyl (meth)acrylate or the like is preferably used.

The weight average molecular weight of the acrylic polymer is preferably 10,000 or greater, particularly preferably 200,000 or greater, and even more preferably 400,000 or greater. 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. The weight average molecular weight (Mw) herein is a value calculated based on standard polystyrene as measured by gel permeation chromatography (GPC).

The acrylic polymer may be used alone or in combination of two or more.

When the adhesive composition contains an acrylic polymer, the content of the acrylic polymer in the adhesive composition is preferably 10% by mass or greater, particularly preferably 12% by mass or greater, and even more preferably 14% by mass or greater. Furthermore, the content is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 14% by mass or less. When the content of the acrylic polymer is within this range, the adhesive properties of the film-forming adhesive are further improved.

(2) Thermosetting component The thermosetting component is a component that has thermosetting properties and is used to thermally cure the film-like adhesive. The thermosetting component is not limited as long as it has thermosetting properties, but preferably includes, for example, epoxy-based thermosetting resins, polyimide resins, and unsaturated polyester resins. The adhesive composition may contain a single thermosetting component or a combination of two or more thermosetting components.

As the thermosetting component in this embodiment, among the examples mentioned above, an epoxy-based thermosetting resin composed of an epoxy resin and a thermosetting agent is preferably used. Furthermore, the epoxy-based thermosetting resin may be used alone or in combination of two or more.

(2-1) Epoxy Resins Examples of epoxy resins include known epoxy resins such as polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenates, o-cresol novolac epoxy resins, dicyclopentadiene epoxy resins, biphenyl epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, and phenylene skeleton epoxy resins, as well as epoxy compounds having two or more functional groups. In this specification, the term "epoxy resin" refers to a curable, i.e., uncured, epoxy resin.

The number average molecular weight of the epoxy resin is not particularly limited, but from the perspective of the curability of the film-form adhesive and the strength and heat resistance of the thermoset of the film-form adhesive, it is preferably 300 or greater, particularly preferably 400 or greater, and even more preferably 500 or greater. 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.

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

Epoxy resins may be used alone or in combination of two or more.

When an epoxy resin is used, the content of the epoxy resin 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 content is preferably 65% by mass or less, particularly preferably 60% by mass or less, and even more preferably 58% by mass or less.

Furthermore, as the epoxy resin, an epoxy resin that is liquid at room temperature can be used, and an epoxy resin that is solid at room temperature can also be used. When using an epoxy resin that is liquid at room temperature, the content of the epoxy resin in the adhesive composition is preferably 2% by mass or more, particularly preferably 3% by mass or more, and even more preferably 4% by mass or more. With a content of 2% by mass or more, solidification of the circuit forming surface at low temperatures becomes easier. Furthermore, the content is preferably 20% by mass or less, particularly preferably 18% by mass or less, and even more preferably 16% by mass or less. With a content of 20% by mass or less, the shape stability of the film-like adhesive becomes even better.

(2-2) Thermohardeners Thermohardeners are hardeners for epoxy resins. The combination of epoxy resin and thermohardener functions as an epoxy-based thermohardening resin. Examples of thermohardeners include compounds having two or more functional groups capable of reacting with epoxy groups within a molecule. Examples of these functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and anhydride-treated acid groups. Among these, at least one of phenolic hydroxyl groups, amino groups, and anhydride-treated acid groups is preferred, with at least one of phenolic hydroxyl groups and amino groups being particularly preferred.

Among thermosetting agents, examples of phenolic curing agents containing phenolic hydroxyl groups include polyfunctional phenolic resins, bisphenol, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins. Furthermore, examples of amine-based curing agents containing amino groups include dicyandiamide (DICY).

Furthermore, thermosetting agents may also contain unsaturated alkyl groups. Examples of thermosetting agents containing unsaturated alkyl groups include compounds in which a portion of the hydroxyl groups of phenolic resins are substituted with groups containing unsaturated alkyl groups, and compounds in which groups containing unsaturated alkyl groups are directly bonded to the aromatic rings of phenolic resins.

When using a phenolic hardener as a thermosetting agent, it is preferred that the thermosetting agent have a high softening point or glass transition temperature in order to facilitate adjustment of the adhesive strength of the film-like adhesive.

Among thermosetting agents, for example, the resin component such as a polyfunctional phenol resin, a novolac phenol resin, a dicyclopentadiene phenol resin, or an aralkyl phenol resin preferably has a number average molecular weight of 300 or greater, particularly preferably 400 or greater, and even more preferably 500 or greater. 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.

The molecular weight of the non-resin component in the thermosetting agent, such as bisphenol and dicyandiamide, is not particularly limited, but is preferably, for example, 60 or more and 500 or less.

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

[Chemistry 1]

In general formula (1), n is an integer greater than or equal to 1, and may be, for example, any of 2 or greater, 4 or greater, and 6 or greater. The upper limit of n is not particularly limited as long as it does not impair the effects of the present invention. For example, an o-cresol-type phenolic resin in which n is 10 or less is easier to produce or obtain.

In the general formula (1), the binding position of the methylene group (—CH ₂ —) linking the o-cresol-diyl groups (—C ₆ H ₄ (—OH)(—CH ₃ )—) to these o-cresol-diyl groups is not particularly limited.

As a thermosetting agent, as can be seen from general formula (1), among phenolic resins, it is preferred that a methyl group is bonded to the carbon atom (carbon atom constituting the benzene ring skeleton) next to the carbon atom to which the phenolic hydroxyl group is bonded, and that steric hindrance is provided near the phenolic hydroxyl group. It is speculated that the thermosetting agent suppresses its reactivity during storage by having such steric hindrance. Furthermore, it is speculated that by using such a thermosetting agent, the reaction of the components contained in the film-like adhesive, such as the curable component, is suppressed during storage, thereby suppressing the change in characteristics. Furthermore, it is speculated that by using such a film-like adhesive with a semiconductor chip, a highly reliable semiconductor package can be obtained.

The film-like adhesive using the thermosetting agent represented by the general formula (1) has such high storage stability that it can be stored at room temperature. For the same reason, the adhesive composition also has such high storage stability that it can be stored at room temperature.

A single heat curing agent may be used alone, or two or more heat curing agents may be used in combination.

When using a thermosetting agent, the content of the thermosetting agent in the adhesive composition is preferably 10% by mass or greater, particularly preferably 15% by mass or greater, and even more preferably 20% by mass or greater. A content of 10% by mass or greater facilitates 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, further improving the reliability of semiconductor packages using the film-like adhesive.

When using an epoxy-based thermosetting resin formed from a combination of an epoxy resin and a thermosetting agent, the content of the epoxy-based thermosetting resin in the adhesive composition is preferably 60% by mass or greater, particularly 65% by mass or greater. A content of 60% by mass or greater improves bonding properties. Furthermore, a content of 85% by mass or less is preferably 85% by mass or less, particularly 80% by mass or less. A content of 85% by mass or less improves storage stability.

The content of the thermosetting agent is preferably greater than 400 parts by mass, particularly preferably 410 parts by mass or greater, and even more preferably 420 parts by mass or greater, relative to 100 parts by mass of the acrylic polymer. Within this range, the heat resistance and adhesion of the thermoset film adhesive are improved, further enhancing the reliability of semiconductor packaging. Furthermore, the upper limit of the content of the thermosetting agent relative to 100 parts by mass of the acrylic polymer can be, for example, 700 parts by mass or less, 600 parts by mass or less, or even 500 parts by mass or less.

The softening point of the thermosetting agent is, for example, preferably 60°C or higher, more preferably 64°C or higher, particularly preferably 68°C or higher, further 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, further preferably 100°C or lower, and most preferably 90°C or lower.

(3) Curing accelerators Curing accelerators are components used to adjust the curing speed of adhesive compositions and film-forming adhesives. Preferred curing accelerators include 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 replaced by groups other than hydrogen atoms); organic phosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (phosphines in which one or more hydrogen atoms are replaced by organic groups); and tetraphenylborates such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

One hardening accelerator may be used alone or in combination of two or more.

When using a curing accelerator, the amount of the curing accelerator is preferably 0.01 parts by mass or greater, and particularly preferably 0.1 parts by mass or greater, per 100 parts by mass of the epoxy-based thermosetting resin (i.e., the total amount of the epoxy resin and the thermosetting agent). A content of 0.01 parts by mass or greater can significantly enhance the effect of the curing accelerator. Furthermore, the amount 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 the epoxy-based thermosetting resin. By setting the content to 5 parts by mass or less, for example, the effect of suppressing the migration and segregation of the highly polar curing accelerator toward the interface with the adherend in the film adhesive under high temperature and high humidity conditions is enhanced, thereby further improving the reliability of semiconductor packages obtained using the film adhesive.

(4) Inorganic fillers By containing inorganic fillers, the thermal expansion coefficient of the film adhesive can be easily adjusted, and the thermal expansion coefficient can be optimized for the object to which the film adhesive is attached, thereby further improving the reliability of the semiconductor package obtained using the film adhesive. In addition, by containing inorganic fillers in the film adhesive, the moisture absorption rate of the thermosetting film adhesive can be reduced or the heat release property can be improved.

Preferred inorganic fillers include powders of silica, aluminum oxide, talc, calcium carbonate, titanium dioxide, red iron, silicon carbide, and boron nitride; beads obtained by sphericalizing these inorganic fillers; surface-modified products of these inorganic fillers; single crystal fibers of these inorganic fillers; and glass fibers.

Among these, the inorganic filler is preferably silica, alumina, or surface-modified materials thereof.

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. By having an average particle size of the inorganic filler within this range, the effects of using the inorganic filler can be fully realized, and the storage stability of the film-form adhesive is further enhanced.

In this specification, the term "average particle size" refers to the particle size at 50% of the cumulative value (D50) in the particle size distribution curve obtained by laser diffraction scattering, unless otherwise specified.

The inorganic filler may be used alone or in combination of two or more.

When an inorganic filler is used, 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 greater, particularly preferably 4% by mass or greater, and even more preferably 6% by mass or greater. Furthermore, the above ratio is preferably 15% by mass or less, particularly preferably 12% by mass or less, and even more preferably 10% by mass or less. By keeping the inorganic filler content within this range, adjustment of the thermal expansion coefficient becomes easier.

However, to further reduce transfer failure, the inorganic filler content is preferably low. From this perspective, the inorganic filler content relative 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 no inorganic filler is contained. Reducing the inorganic filler content can suppress a decrease in the cohesive strength of the film-forming adhesive, which is believed to ultimately reduce the occurrence of transfer failure.

(5) Coupling agent The film adhesive contains a coupling agent, which improves the adhesion and adhesion to the substrate. In addition, the film adhesive contains a coupling agent, which not only does not impair the heat resistance of the thermosetting product, but also improves the water resistance. The coupling agent has a functional group that can react with an inorganic compound or an organic compound.

The coupling agent is preferably an acrylic polymer or a compound having a functional group that can react with a functional group of an epoxy-based thermosetting resin, and more preferably a silane coupling agent.

Preferred silane coupling agents include, for example, 3-glycidyl propoxy trimethoxy silane, 3-glycidyl propoxy methyl diethoxy silane, 3-glycidyl propoxy triethoxy silane, 3-glycidyl oxymethyl diethoxy silane, 2-(3,4-epoxycyclohexyl) ethyl trimethoxy silane, 3-methacryloyl propoxy trimethoxy silane, 3-aminopropyl trimethoxy silane, 3-(2-aminoethylamino) ... 3-(phenylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-acylureapropyltriethoxysilane, 3-butyltrimethoxysilane, 3-butylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazole silane, oligomeric or polymeric organosiloxanes, etc.

The coupling agents may be used alone or in combination of two or more.

When a coupling agent is used, the amount of coupling agent in the adhesive composition is preferably 0.03 parts by mass or greater, particularly preferably 0.05 parts by mass or greater, and even more preferably 0.1 parts by mass or greater, relative to 100 parts by mass of the total content of the acrylic polymer and the epoxy-based thermosetting resin. A coupling agent content of 0.03 parts by mass or greater can significantly enhance the effects of the coupling agent, such as improved dispersibility of the inorganic filler in the resin and improved adhesion of the film-form adhesive to the adherend. Furthermore, the coupling agent content 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, relative to 100 parts by mass of the total content of the acrylic polymer and the epoxy-based thermosetting resin. By setting the coupling agent content to 20 parts by mass or less, the occurrence of outgassing is further suppressed.

(6) Crosslinking Agents When using the above-mentioned acrylic polymers having functional groups such as vinyl, (meth)acryl, amino, hydroxyl, carboxyl, and isocyanate groups that can bond with other compounds, the adhesive composition and film-like adhesive may contain a crosslinking agent for bonding the above-mentioned functional groups with other compounds and crosslinking. By using a crosslinking agent and performing crosslinking, the initial adhesion and cohesive strength of the film-like adhesive can be adjusted.

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 acridine crosslinking agents (crosslinking agents having an aziridinyl group).

Examples of the organic polyvalent isocyanate compounds include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, and alicyclic polyvalent isocyanate compounds (hereinafter, these compounds may be collectively referred to as "aromatic polyvalent isocyanate compounds, etc."); trimers, isocyanurates, and adducts of the above aromatic polyvalent isocyanate compounds, etc.; and isocyanate-terminated urethane prepolymers obtained by reacting the above aromatic polyvalent isocyanate compounds, etc. with polyol compounds. The "adducts" mentioned above refer to the reaction products of the above aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, or alicyclic polyvalent isocyanate compounds with compounds containing low-molecular-weight active hydrogen, such as ethylene glycol, propylene glycol, neopentyl glycol, trihydroxymethylpropane, or castor oil. Examples of such adducts include the trihydroxymethylpropane-xylylene diisocyanate adduct described below. Furthermore, the term "isocyanate-terminated urethane prepolymer" refers to a prepolymer having a urethane bond and an isocyanate group at the terminal end of the molecule.

More specifically, the organic polyvalent isocyanate compounds include 2,4-methylenediisocyanate; 2,6-methylenediisocyanate; 1,3-xylene diisocyanate; 1,4-xylene diisocyanate; diphenylmethane-4,4'-diisocyanate; diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethyldisilazane; Methylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; compounds formed by adding one or more of methylenediisocyanate, hexamethylenediisocyanate, and xylene diisocyanate to all or part of the hydroxyl groups of a polyol such as trihydroxymethylpropane; lysine diisocyanate, etc.

Examples of the organic polyvalent imine compound include N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), trihydroxymethylpropane-tris-β-aziridinylpropionate, tetrahydroxymethylmethane-tris-β-aziridinylpropionate, and N,N'-toluene-2,4-bis(1-aziridinecarboxamide)triethylenemelamine.

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

A single crosslinking agent may be used alone, or two or more may be used in combination.

The crosslinking agent content is preferably 0 parts by mass or greater, more preferably 0.1 parts by mass or greater, and even more preferably 0.2 parts by mass or greater, per 100 parts by mass of the acrylic polymer. When the crosslinking agent content is 0 parts by mass or greater, the effect of using the crosslinking agent is more pronounced. 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, per 100 parts by mass of the acrylic polymer. When the crosslinking agent content is 5 parts by mass or less, the storage stability of the film-form adhesive is further enhanced.

(7) Active energy ray-curable resins Active energy ray-curable resins are resins that 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.

Examples of the polyfunctional (meth)acrylate monomer include monofunctional acrylates such as cyclohexyl (meth)acrylate and isoborneol (meth)acrylate; polyfunctional acrylates such as trihydroxymethylenepropane 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 dihydroxymethyltricyclodecane di(meth)acrylate; polyester oligo(meth)acrylates; and polyurethane oligo(meth)acrylates.

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 facilitates separation of the thin film adhesive (adhesive layer 11) from the interfacial peeling layer 12. Furthermore, the content of the active energy ray-curable resin in the adhesive composition can be 0.1% by mass or more, and particularly 2% by mass or more. A content of 0.1% by mass or more of the active energy ray-curable resin further improves the curability of the film adhesive.

(8) Photopolymerization initiator When the adhesive composition contains an active energy ray-curable resin, it is also preferable to further contain a photopolymerization initiator. This allows the film-like adhesive to be cured more efficiently.

Specific examples of the photopolymerization initiator 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, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2- Linoyl-propane-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, 2-dimethylamino-2-(4-methylbenzyl)-1-(4- 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-methylpropanone, ethyl ketone, 1-[9-ethyl-6-(2-methylbenzyl)-9H-carbazol-3-yl]-1-(0-acetyl oxime), diphenyl ketone, p-phenyl diphenyl ketone, 4,4'-diethylamino diphenyl ketone, dichlorodiphenyl ketone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthio Ketone, 2-ethylthio Ketone, 2-chlorothio Ketone, 2,4-dimethylthio Ketone, 2,4-diethylthio Ketone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, oligo[2-hydroxy-2-methyl-1[4-(1-methylvinyl)phenyl]propanone], 2-benzyl-2-(dimethylamino)-4'-N- Phylinobutylbenzene, bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, etc. These may be used alone or in combination of two or more.

Furthermore, it is preferred that the photopolymerization initiator have an absorption peak that is not located at the wavelength of the laser light used to cause interfacial erosion. This facilitates and effectively causes interfacial erosion during laser irradiation.

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 greater, particularly preferably 1% by mass or greater. A content of 0.5% by mass or greater allows the active energy ray-curable resin in the film-forming adhesive to cure more efficiently. Furthermore, the content of the photopolymerization initiator in the adhesive composition is preferably 15% by mass or less, particularly preferably 10% by mass or less. A content of 15% by mass or less allows the film-forming adhesive to have enhanced storage stability.

(9) Other ingredients

The adhesive composition may contain ingredients other than those listed above. For example, it may contain a plasticizer, an antistatic agent, an antioxidant, a colorant (dyes, pigments), a gettering agent, etc. These may be used alone or in combination of two or more.

(10) Preparation method of adhesive composition The adhesive composition can be obtained by blending the above-mentioned components. The order of adding the components when blending is not particularly limited, and two or more components can be added simultaneously.

When a solvent is used, the solvent may be mixed with any blending component other than the solvent and the blending component may be diluted in advance before use, or the solvent may be mixed with the blending component without diluting any blending component other than the solvent in advance.

The method for mixing the components during blending is not particularly limited and may be appropriately selected from the following known methods: a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer; a method of mixing by applying ultrasonic waves, etc.

The temperature and time during the addition and mixing of the components are not particularly limited as long as the mixed components do not deteriorate, and can be appropriately adjusted, but the temperature is preferably 15 to 30°C.

The solvent is not particularly limited, but preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutanol (2-methylpropane-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. Of these, toluene and methyl ethyl ketone are preferred because they allow for more uniform mixing of the components in the adhesive composition. These solvents may be used alone or in combination.

(11) Thickness The thickness of the adhesive layer 11 in this embodiment is preferably 1 μm or more, particularly preferably 2 μm or more, and more preferably 3 μm or more. When the thickness of the adhesive layer 11 is 1 μm or more, it is easy to exhibit sufficient bonding strength to the small workpiece. In addition, the thickness of the adhesive layer 11 is preferably 30 μm or less, particularly preferably 25 μm or less, and more preferably 15 μm or less. When the thickness of the adhesive layer 11 is 30 μm or less, separation caused by interface corrosion becomes easy to occur.

2. Interface Peeling Layer The specific structure and composition of the interface peeling layer 12 in this embodiment are not particularly limited, as long as it enables interface peeling by laser light irradiation. A preferred example of the interface peeling layer 12 is an adhesive layer. By having the interface peeling layer 12 function as an adhesive layer, it facilitates good adhesion of the adhesive layer 11.

When the interfacial peeling layer 12 is an adhesive layer, the adhesive constituting the adhesive layer may be an adhesive having active energy ray curing properties (active energy ray curing adhesive) or an adhesive not having active energy ray curing properties (non-active energy ray curing adhesive).

Furthermore, from the perspective of easily producing good interfacial corrosion, the interfacial corrosion layer 12 preferably contains at least one additive selected from the group consisting of a UV absorber and a photopolymerization initiator.

(1) Active energy ray hardening adhesive In the case where the interfacial peeling layer 12 is an adhesive layer composed of an active energy ray hardening adhesive, the adhesion at the interface between the interfacial peeling layer 12 and the adhesive layer 11 (film adhesive) can be reduced by irradiation with active energy rays. Therefore, before or simultaneously with the occurrence of the above-mentioned interfacial peeling, the adhesion is reduced by irradiation with active energy rays, thereby enabling the small piece of workpiece with the film adhesive attached to be reliably separated from the interfacial peeling layer 12. In addition, the irradiation amount of laser light required to fully produce the separation can also be reduced. Furthermore, since the adhesiveness to the adhesive layer 11 can be reduced by irradiation with active energy rays, the adhesiveness can be set high before irradiation with active energy rays. This makes it easier to prevent the adhesive layer 11 from peeling off during dicing, etc.

The active energy ray-curable adhesive may be any of acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, and polyvinyl ether adhesives. However, acrylic adhesives are preferred from the perspective of easily exerting the desired adhesive force.

Furthermore, the active energy ray-curable adhesive may be composed primarily of a polymer having active energy ray curability, or may be composed primarily of a mixture of a non-active energy ray-curable polymer (a polymer not having active energy ray curability) and a monomer and/or oligomer having at least one active energy ray-curable group. Furthermore, it may be a mixture of an active energy ray-curable polymer and a non-active energy ray-curable polymer, 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.

First, the following describes the case where the active energy ray-curable adhesive contains a polymer having active energy ray curability as a main component.

The active energy ray-curable polymer is preferably a (meth)acrylate (co)polymer (A) (hereinafter referred to as "active energy ray-curable polymer (A)") having energy ray-curable functional groups (active energy ray-curable groups) introduced into the side chains. The active energy ray-curable polymer (A) is preferably obtained by reacting an acrylic copolymer (a1) having monomer units containing functional groups with an unsaturated group-containing compound (a2) having a functional group that is bonded to the functional group.

The acrylic copolymer (a1) preferably comprises a constituent unit derived from a monomer having a functional group and a constituent unit derived from a (meth)acrylate monomer or a derivative thereof.

The functional group-containing monomer 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, a carboxyl group, an amino group, a substituted amino group, or an epoxy group in the molecule.

Examples of monomers containing a hydroxy group 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. These monomers can be used alone or in combination of two or more.

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

Examples of monomers containing amino groups or monomers containing substituted amino groups include aminoethyl (meth)acrylate and n-butylaminoethyl (meth)acrylate. These monomers may be used alone or in combination of two or more.

As the (meth)acrylate monomer constituting the acrylic copolymer (a1), in addition to (meth)acrylates having an alkyl group with 1 to 20 carbon atoms, monomers having an alicyclic structure in the molecule (monomers containing an alicyclic structure) are preferably used.

As the alkyl (meth)acrylate, particularly preferred are those having an alkyl group with 1 to 18 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. These may be used alone or in combination of two or more.

Preferred monomers containing an alicyclic structure include, for example, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, adamantyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate. These monomers may be used alone or in combination of two or more.

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

Furthermore, the acrylic copolymer (a1) preferably contains constituent units derived from a (meth)acrylate monomer or a derivative thereof in a ratio of 50% by mass or more, particularly preferably 60% by mass or more, and even more preferably 70% by mass or more. Furthermore, the acrylic copolymer (a1) preferably contains constituent units derived from a (meth)acrylate monomer or a derivative thereof in a ratio of 99% by mass or less, particularly preferably 95% by mass or less, and even more preferably 90% by mass or less.

The acrylic copolymer (a1) is obtained by copolymerizing the above-mentioned functional group-containing monomers with (meth)acrylate monomers or their derivatives by conventional methods. In addition to these monomers, dimethylacrylamide, vinyl formate, vinyl acetate, styrene, etc. may also be copolymerized.

The active energy ray-curable polymer (A) is obtained by reacting an acrylic copolymer (a1) having a monomer unit containing a functional group and a compound (a2) containing an unsaturated group having a functional group bonded to the functional group.

The functional group of the unsaturated group-containing compound (a2) can be appropriately selected depending on the type of functional group of the functional group-containing monomer unit of the acrylic copolymer (a1). For example, when 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. When 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 aziridine group.

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 in one molecule. Specific examples of such unsaturated group-containing compound (a2) include 2-methacryloyloxyethyl isocyanate, methyl-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1,1-(diacryloyloxymethyl)ethyl isocyanate; and the reaction of a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth)acrylate. Acryloyl monoisocyanate compounds obtained by reaction; Acryloyl monoisocyanate compounds obtained by the reaction of a diisocyanate compound or a polyisocyanate compound, 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.

The unsaturated group-containing compound (a2) is preferably used in a proportion of 50 mol% or more, particularly preferably 60 mol% or more, and even more preferably 70 mol% or more, based on the molar number of the functional group-containing monomer in the acrylic copolymer (a1). Furthermore, the unsaturated group-containing compound (a2) is preferably used in a proportion of 95 mol% or less, particularly preferably 93 mol% or less, and even more preferably 90 mol% or less, based on the molar number of the functional group-containing monomer in the acrylic copolymer (a1).

In the reaction between the acrylic copolymer (a1) and the unsaturated group-containing compound (a2), the reaction temperature, pressure, solvent, reaction time, presence or absence of a catalyst, and the type of catalyst can be appropriately selected according to the combination of the functional groups of the acrylic copolymer (a1) and the functional groups of the unsaturated group-containing compound (a2). Thus, the functional groups 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), thereby obtaining an active energy ray-curable polymer (A).

The weight average molecular weight (Mw) of the active 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 1.5 million or less, particularly preferably 1.25 million or less, and even more preferably 1 million or less.

Even when the active energy ray-curable adhesive contains a polymer having active energy ray curability such as an active energy ray-curable polymer (A) as a main component, the active energy ray-curable adhesive may further contain an energy ray-curable monomer and/or oligomer (B).

As the active energy ray-curable monomer and/or oligomer (B), for example, esters of polyols and (meth)acrylic acid can be used.

Examples of the active energy ray-curable monomer and/or oligomer (B) include monofunctional acrylates such as cyclohexyl (meth)acrylate and isoborneol (meth)acrylate; polyfunctional acrylates such as trihydroxymethylpropane 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 dihydroxymethyltricyclodecane di(meth)acrylate; polyester oligo(meth)acrylates, and polyurethane oligo(meth)acrylates.

When the active energy ray-curable polymer (A) is mixed 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 greater than 0 parts by mass, and particularly preferably 60 parts by mass or greater, relative to 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, relative to 100 parts by mass of the active energy ray-curable polymer (A).

Next, the following description will be made regarding the case where the active energy ray-curable adhesive comprises, as a main component, a mixture of an active energy ray non-curable polymer component and a monomer and/or oligomer having at least one active energy ray-curable group.

As the active energy ray non-hardening polymer component, for example, the same components as the above-mentioned acrylic copolymer (a1) can be used.

The monomer and/or oligomer having at least one active energy ray-curable group can be selected from the same components as those described for component (B). 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 greater, and particularly preferably 60 parts by mass or greater, 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. Furthermore, the blending ratio is preferably 200 parts by mass or less, and particularly preferably 160 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.

(2) Inactive Energy Ray Curing Adhesive In the case where the interface peeling layer 12 is an adhesive layer composed of an inactive energy ray curing adhesive, the adhesive may be any of acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, and polyvinyl ether adhesives. However, acrylic adhesives are preferred from the perspective of being able to easily exert the desired adhesive force.

Examples of acrylic adhesives that are non-active energy ray-curable adhesives include those containing the aforementioned non-active energy ray-curable polymer component. The non-active energy ray-curable polymer component may be the same as the acrylic copolymer (a1) described above. Furthermore, the non-active energy ray-curable adhesive may not contain the aforementioned polymer having active energy ray curability and the aforementioned monomer and/or oligomer having at least one active energy ray-curable group.

(3) Additives As mentioned above, from the perspective of easily generating interfacial corrosion, the interfacial corrosion inhibitor 11 in this embodiment preferably contains at least one additive selected from the group consisting of a UV absorber and a photopolymerization initiator.

(3-1) Ultraviolet Absorber The type of ultraviolet absorber in this embodiment is not particularly limited. The ultraviolet absorber in this embodiment may be an organic compound or an inorganic compound, but organic compounds are preferred from the perspective of easily producing good interfacial corrosion resistance.

When the UV absorber is an organic compound, preferred examples of the UV absorber include hydroxyphenyltriazine-based UV absorbers, diphenyl ketone-based UV absorbers, benzotriazole-based UV absorbers, benzoate-based UV absorbers, benzophenone-based UV absorbers, phenyl salicylate-based UV absorbers, cyanoacrylate-based UV absorbers, nickel cerium salt-based UV absorbers, hydroquinone-based UV absorbers, salicylic acid-based UV absorbers, malonate-based UV absorbers, and oxalic acid-based UV absorbers. These compounds may be used alone or in combination.

Among the aforementioned UV absorbers, at least one of hydroxyphenyl trisulphide-based UV absorbers, diphenyl ketone-based UV absorbers, and benzotriazole-based UV absorbers is preferred, particularly hydroxyphenyl trisulphide-based UV absorbers, due to their excellent absorption in the third harmonic wave (355 nm) of YAG and their ability to easily induce good interfacial erosion.

Examples of the hydroxyphenyl trisulphonium-based ultraviolet absorbers include 2-[4-(octyl-2-acetic acid methyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)]-1,3,5-trisulphonium, 2-[4-(2-hydroxy-3-dodecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)]-1,3,5-trisulphonium, (2,4-dimethylphenyl)-1,3,5-trisinium, 2-[4-(2-hydroxy-3-tridecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-trisinium, 2-(2,4-dihydroxyphenyl)-4,6-bis-(2,4-dimethylphenyl)-1, 3,5-trisinium, 2-[4-(2-hydroxy-3-(2'-ethyl)hexyloxy]-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-trisinium, 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3-5-trisinium, 2-( 2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-trisinium, tris[2,4,6-[2-{4-(octyl-2-acetic acid methyl)oxy-2-hydroxyphenyl}]-1,3,5-trisinium. These may be used alone or in combination of two or more.

Among these, at least one of 2,4,6-[2-{4-(octyl-2-acetate)oxy-2-hydroxyphenyl}]-1,3,5-trisinium, 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-trisinium, 2-[4-(2-hydroxy-3-dodecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-trisinium, and 2-[4-(2-hydroxy-3-tridecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-trisinium is preferably used.

When the UV absorber is an organic compound, it is preferably a compound having one or more heterocyclic rings in its chemical structure. In this case, the number of heterocyclic rings is preferably 4 or less, and particularly preferably 1.

Furthermore, as another chemical structural feature, the UV absorber in this embodiment preferably has at least one of a carbon ring and a heterocyclic ring, and all the carbon rings and heterocyclic rings possessed by the UV absorber are monocyclic.

As another chemical structural feature, the UV absorber in this embodiment is preferably a compound having multiple aromatic rings. In this case, the number of aromatic rings is preferably 2 or more. Furthermore, the number of aromatic rings is preferably 6 or less, and particularly preferably 3 or less.

In the chemical structural characteristics described above, each heterocyclic ring preferably contains at least one element selected from nitrogen, oxygen, phosphorus, sulfur, silicon, and selenium as a constituent element other than carbon, and particularly preferably contains at least one element selected from nitrogen, oxygen, phosphorus, and sulfur. Furthermore, the number of atoms constituting the heterocyclic ring structure is not particularly limited, but is, for example, 3 or more and 9 or less, and particularly preferably 5 or more and 6 or less. Specific examples of preferred heterocyclic rings include trisinium, benzotriazole, thiophene, pyrrole, imidazole, pyridine, and pyrrolidone.

Among the above-mentioned chemical structural characteristics, preferred examples of aromatic rings include benzene, naphthalene, anthracene, biphenyl, and triphenyl.

As an example of a UV absorber having the above-mentioned chemical structural characteristics, [2,4,6-[2-{4-(octyl-2-acetic acid methyl)oxy-2-hydroxyphenyl}]-1,3,5-triazine can be cited.

In this embodiment, when the interfacial peeling layer 12 contains a UV absorber, the content of the UV absorber in the interfacial peeling layer 12 is preferably 1% by mass or greater, particularly preferably 3% by mass or greater, and even more preferably 5% by mass or greater. When the UV absorber content is 1% by mass or greater, the interfacial peeling layer 12 efficiently absorbs laser light, thereby facilitating good interfacial peeling. Furthermore, the content of the UV absorber in the interfacial peeling layer 12 is preferably 75% by mass or less, particularly preferably 40% by mass or less, and even more preferably 25% by mass or less. By setting the content of the ultraviolet absorber to 75% by mass or less, the viscosity of the material used to form the interface peeling layer 12 becomes appropriate, making it easier to ensure good film forming properties.

Furthermore, in the present embodiment, when the interfacial peeling layer 12 is formed from the adhesive composition described below, a UV absorber may also be incorporated into the adhesive composition. In this case, the amount of the UV absorber incorporated into the adhesive composition is preferably 1% by mass or greater, particularly preferably 3% by mass or greater, and even more preferably 5% by mass or greater. With an amount of the UV absorber incorporated into the adhesive composition of 1% by mass or greater, the interfacial peeling layer 12 efficiently absorbs laser light, thereby facilitating good interfacial peeling. Furthermore, the amount of the UV absorber incorporated into the adhesive composition is preferably 75% by mass or less, particularly preferably 40% by mass or less, and even more preferably 20% by mass or less. By setting the blending amount of the UV absorber to 75% by mass or less, the resulting adhesive can easily exhibit the desired adhesive strength.

(3-2) Photopolymerization initiator

The photopolymerization initiator in this embodiment is not particularly limited. When the interfacial peeling layer 12 is an adhesive layer composed of an active energy ray-curable adhesive, the interfacial peeling layer 12 preferably contains a photopolymerization initiator. This facilitates efficient interfacial peeling and allows the interfacial peeling layer 12 to cure efficiently.

Specific examples of the photopolymerization initiator 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, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2- Linoyl-propane-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, 2-dimethylamino-2-(4-methylbenzyl)-1-(4- 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-methylpropanone, ethyl ketone, 1-[9-ethyl-6-(2-methylbenzyl)-9H-carbazol-3-yl]-1-(0-acetyl oxime), diphenyl ketone, p-phenyl diphenyl ketone, 4,4'-diethylamino diphenyl ketone, dichlorodiphenyl ketone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthio Ketone, 2-ethylthio Ketone, 2-chlorothio Ketone, 2,4-dimethylthio Ketone, 2,4-diethylthio Ketone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, oligo[2-hydroxy-2-methyl-1[4-(1-methylvinyl)phenyl]propanone], 2-benzyl-2-(dimethylamino)-4'-N- Phylinobutylbenzene, bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, etc. These may be used alone or in combination of two or more.

Among the above-mentioned photopolymerization initiators, 2-dimethylamino-2-(4-methylbenzyl)-1-(4- 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(0-acetyl oxime), 2-benzyl-2-(dimethylamino)-4'- At least one of phenoxybutylbenzene, bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, and 2,2-dimethoxy-1,2-diphenylethane-1-one.

In this embodiment, when the interfacial peeling layer 12 contains a photopolymerization initiator, the content of the photopolymerization initiator in the interfacial peeling layer 12 is preferably 1% by mass or greater, particularly preferably 3% by mass or greater, and even more preferably 5% by mass or greater. When the content of the photopolymerization initiator is 1% by mass or greater, the interfacial peeling layer 12 efficiently absorbs laser light, thereby facilitating good interfacial peeling. Furthermore, the content of the photopolymerization initiator in the interfacial peeling layer 12 is preferably 75% by mass or less, particularly preferably 40% by mass or less, and even more preferably 25% by mass or less. By keeping the photopolymerization initiator content at 75% by mass or less, the viscosity of the material used to form the interfacial peeling layer 12 becomes appropriate, making it easier to ensure good film-forming properties.

Furthermore, in the case where the interfacial peeling layer 12 in this embodiment is formed from the adhesive composition described below, a photopolymerization initiator may also be incorporated into this adhesive composition. In this case, the amount of the photopolymerization initiator incorporated into the adhesive composition is preferably 1% by mass or greater, particularly preferably 3% by mass or greater, and even more preferably 5% by mass or greater. By incorporating the photopolymerization initiator into the adhesive composition at an amount of 1% by mass or greater, the interfacial peeling layer 12 efficiently absorbs laser light, thereby facilitating good interfacial peeling. Furthermore, the amount of the photopolymerization initiator incorporated into the adhesive composition is preferably 75% by mass or less, particularly preferably 40% by mass or less, and even more preferably 25% by mass or less. By setting the blending amount of the photopolymerization initiator to 75% by mass or less, the resulting adhesive easily exhibits the desired adhesive strength.

(4) Other ingredients

The adhesive constituting the interfacial peeling layer 12 of this embodiment may also contain other suitable components. Examples of these other components include crosslinking agents, active energy ray non-hardening polymer components, and oligomer components.

From the perspective of easily adjusting the storage modulus of the interfacial peeling layer 12 to the desired range, it is preferable to use a crosslinking agent. As the crosslinking agent, a polyfunctional compound reactive with the functional groups of the active energy ray-curable polymer (A) and the acrylic copolymer (a1) can be used. Examples of such polyfunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, azide compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts, and reactive phenolic resins.

The amount of the crosslinking agent blended per 100 parts by mass of the main agent is preferably 0.001 parts by mass or greater, particularly preferably 0.1 parts by mass or greater, and even more preferably 0.2 parts by mass or greater. Furthermore, the amount of the crosslinking agent blended per 100 parts by mass of the main 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. Furthermore, the "main agent" referred to above refers to the aforementioned active energy ray-curable polymer (A) when the interfacial peeling layer 12 is composed of an active energy ray-curable adhesive, and refers to the aforementioned acrylic copolymer (a1) when the interfacial peeling layer 12 is composed of a non-active energy ray-curable adhesive.

Examples of the aforementioned active energy ray-resistant non-hardening polymer or oligomer components include polyacrylates, polyesters, polyurethanes, polycarbonates, and polyolefins, preferably with a weight-average molecular weight (Mw) of 3,000 to 2,500,000. By incorporating these components, adhesiveness, releasability, adhesion to other layers, and storage stability can be improved.

(5) Thickness of the Interface Peeling Layer In this embodiment, the thickness of the interface peeling layer 12 is preferably 3 μm or greater, particularly preferably 20 μm or greater, and even more preferably 25 μm or greater. Furthermore, the thickness of the interface peeling layer 12 is preferably 100 μm or less, particularly preferably 50 μm or less, and even more preferably 40 μm or less. By having the thickness of the interface peeling layer 12 within the above range, it is easy to achieve both retention of the workpiece chips on the interface peeling layer 12 and separation of the workpiece chips due to interface peeling.

3. Substrate The composition, physical properties, etc. of the substrate 13 in this embodiment are not particularly limited. To facilitate the desired function of the workpiece processing sheet 1, the substrate 13 is preferably made of a resin. When the substrate 13 is composed of a resin, examples of the resin 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-(meth)acrylic acid copolymer, ethylene-methyl (meth)acrylate copolymer, and other ethylene-(meth)acrylate copolymers; polyvinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers; (meth)acrylate copolymers; polyurethane; polyimide; polystyrene; polycarbonate; fluororesins, etc. Furthermore, the resin constituting the substrate 13 may be cross-linked with the aforementioned resins, or may be a modified ionomer of the aforementioned resins. Furthermore, the substrate 13 may be a single-layer film composed of the aforementioned resins, or a laminated film composed of multiple layers of such films. In such a laminated film, the materials constituting each layer may be the same or different.

To improve adhesion to the interfacial peeling layer 12, the surface of the substrate 13 in this embodiment may be subjected to surface treatment such as oxidation or embossing, or to a primer treatment. Examples of oxidation methods include coma discharge treatment, plasma discharge treatment, chromating (wet), flame treatment, hot air treatment, ozone, and ultraviolet irradiation. Examples of embossing methods include sandblasting and spraying.

The substrate 13 in this embodiment may contain various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, fillers, etc. Furthermore, when the interfacial peeling layer 12 comprises a material that is hardened by active energy rays, the substrate 13 is preferably permeable to the active energy rays.

The method for manufacturing the substrate 13 in this embodiment is not particularly limited as long as the substrate 13 is made of a resin. For example, the substrate 13 can be manufactured by forming the resin into a sheet using a melt extrusion method such as a T-die method or a circular die method; a calender method; or a solution method such as a dry method or a wet method.

In this embodiment, the thickness of the substrate 13 is preferably 10 μm or greater, particularly preferably 30 μm or greater, and even more preferably 50 μm or greater. Furthermore, the thickness of the substrate 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. By having the thickness of the substrate 13 within this range, the workpiece processing sheet 1 possesses a desired balance of rigidity and flexibility, making it easy to process small workpieces.

4. Peel Sheet In this embodiment, if the interfacial peeling layer 12 includes an adhesive as one of its components, a peeling sheet may be deposited on the surface of the interfacial peeling layer 12 opposite the substrate 13 to protect it before it is attached to the workpiece.

The composition of the release sheet is arbitrary, and examples thereof include plastic films that have been treated with a release agent. Specific examples of such plastic films include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; and polyolefin films such as polypropylene and polyethylene. The release agent can be a silicone-based, fluorine-based, or long-chain alkyl-based agent. Among these, silicone-based agents are preferred due to their low cost and stable performance.

The thickness of the release sheet is not particularly limited, and may be, for example, 20 μm or more and 250 μm or less.

5. Workpiece Processing Sheet Manufacturing Method The method for manufacturing the workpiece processing sheet 1 of this embodiment is not particularly limited. For example, after separately obtaining a laminate comprising an adhesive layer 11 formed on a release sheet and an interfacial peeling layer 12 formed on a substrate 13, these adhesive layer 11 and interfacial peeling layer 12 are laminated together to obtain the workpiece processing sheet 1.

The adhesive layer 11 can be formed using known methods. For example, an adhesive composition for forming the adhesive layer 11 and, if desired, a coating liquid containing a solvent or a dispersant are prepared. The coating liquid is then applied to the releasable surface of a release sheet (hereinafter referred to as the "release surface"). The resulting coating is then dried to form the adhesive layer 11. Furthermore, a separate release sheet can be attached to the exposed surface of the adhesive layer 11 before the interfacial peeling layer 12 is deposited.

The interfacial peeling layer 12 can also be formed using known methods. When an adhesive is included as one of the components constituting the interfacial peeling layer 12, for example, an adhesive composition for forming the interfacial peeling layer 12 and, if desired, a coating liquid containing a solvent or a dispersant are prepared. The coating liquid is then applied to the peeling surface of the peeling sheet. The resulting coating is then dried, and after the interfacial peeling layer 12 is formed, the substrate 11 is attached to the surface exposed by the interfacial peeling layer 12. Alternatively, the interfacial peeling layer 12 can be formed directly on the substrate 11.

The coating liquid can be applied by known methods, such as rod coating, knife coating, roll coating, blade coating, die coating, gravure coating, etc. The properties of the coating liquid are not particularly limited as long as it allows for coating. The coating liquid may contain a component used to form the adhesive layer 11 and the interfacial peeling layer 12 as a solute or a component used to form the adhesive layer 11 and the interfacial peeling layer 12 as a dispersant. Furthermore, when the adhesive layer 11 is already formed on the release sheet, the release sheet can be used as a step material for release, or it can protect the adhesive layer 11 until it is attached to the adherend.

When the aforementioned adhesive composition and adhesive composition contain the aforementioned crosslinking agent, it is preferred to modify the aforementioned drying conditions (temperature, time, etc.) or provide a separate heat treatment to promote a crosslinking reaction between the polymer components in the coating and the crosslinking agent, thereby forming a crosslinked structure at a desired density within the adhesive layer 11 and the interfacial etch layer 12. Furthermore, to ensure sufficient crosslinking, the workpiece processing sheet 1 may be left to mature for several days, for example, at 23°C and a relative humidity of 50%.

6. Method of Using the Workpiece Processing Sheet The workpiece processing sheet 1 of this embodiment is preferably used for workpiece manipulation. An example of a method of using the workpiece processing sheet 1 of this embodiment is as follows: While the workpiece is being held on the surface of the adhesive layer 11 opposite the interfacial peeling layer 12, the workpiece and the adhesive layer 11 are integrated to obtain a plurality of layers composed of small pieces of the workpiece and small pieces of the adhesive layer 11. Then, at least one of the layers is selectively separated from the interfacial peeling layer 12 by locally generating interfacial peeling in the interfacial peeling layer 12.

Furthermore, instead of singulating the workpieces on the workpiece processing sheet 1 as described above, pre-singulated workpiece pieces may be attached to the adhesive layer 11 side of the workpiece processing sheet 1. In this case, only the adhesive layer 11 is singulated together with the workpiece pieces.

As examples of the above-mentioned workpieces, as mentioned above, semiconductor wafers, semiconductor packages, glass plates, etc. can be cited. In the workpiece processing sheet 1 of this embodiment, even extremely thin workpieces can be operated without being damaged. For example, if the workpiece processing sheet 1 according to this embodiment is used, workpieces with a thickness of less than 150 μm can be preferably operated, especially workpieces with a thickness of less than 100 μm can be preferably operated, and further, workpieces with a thickness of less than 50 μm can be preferably operated. In addition, workpieces with thicknesses exceeding these ranges can also be operated. In addition, the lower limit value of the thickness is not particularly limited, and can be greater than 150 μm, especially greater than 100 μm, and further, greater than 50 μm.

Hereinafter, as a preferred method of using the workpiece processing sheet 1 of this embodiment, a method of manufacturing a semiconductor device will be specifically described based on FIG. 3 . The manufacturing method includes, for example, a singulation step, in which the workpiece and the adhesive layer 11 are singulated together while the workpiece is maintained on the surface of the adhesive layer 11 side in the workpiece processing sheet 1 of this embodiment, thereby obtaining a plurality of layer integrated by small pieces of the workpiece and small pieces of the adhesive layer 11; an irradiation step, in which laser light is irradiated to the position where at least one of the above-mentioned layer integrated is maintained in the interface peeling layer 12, thereby generating interface peeling at the irradiated position in the interface peeling layer 12; and a picking step, in which the above-mentioned layer integrated at the position where the interface peeling is generated is picked up from the workpiece processing sheet 1.

In the singulation step described above, as shown in Figure 3(a), the workpiece 2 is first attached to the adhesive layer 11 of the workpiece processing sheet 1. Furthermore, although not shown, a ring frame can be attached to locations on the workpiece processing sheet 1 where the workpiece 2 is not deposited. In particular, the illustrated workpiece processing sheet 1 is configured such that the adhesive layer 11 is smaller than the interface peeling layer 12, thereby exposing the interface peeling layer 12. The ring frame can then be attached to these exposed locations. Here, if the interfacial peeling layer 12 is an adhesive layer, the annular frame can be directly attached to the interfacial peeling layer 12. Alternatively, if it is not an adhesive layer, the annular frame can be attached through the adhesive layer. Furthermore, even when using the workpiece processing sheet 1 shown in FIG. 1 (where the adhesive layer 11 and the interfacial peeling layer 12 are substantially the same when viewed from above), the annular frame can be attached.

Next, as shown in Figure 3(b), the workpiece 2 and the adhesive layer 11 are separated. This separation can be performed using a known method, particularly preferably by dicing with a dicing blade. This dicing can also be performed using known methods. By separating, the workpiece 2 is separated into small workpiece pieces 2', and the adhesive layer 11 is separated into thin film-like adhesive 11'.

Next, as shown in Figure 3(c), in the irradiation step, laser light 3 is irradiated onto the interface etch layer 12 to produce interface etch. This irradiation can be performed simultaneously at multiple locations where the layer (composed of the workpiece chip 2' and the thin film adhesive 11') exists. However, from the perspective of facilitating the selective separation of the layer, it is preferred to irradiate only the locations where the layer to be separated exists.

As shown in the figure, laser light 5 irradiates the area of interfacial peeling layer 12 near substrate 13, causing the components in that area to evaporate or volatilize, forming a reaction zone 12'. The gases generated by this evaporation or volatilization then accumulate between substrate 13 and reaction zone 12', forming bubbles 12''. The formation of bubbles 12'' locally deforms interfacial peeling layer 12, causing partial separation between the layer located there (composed of workpiece chip 2' and thin film adhesive 11') and interfacial peeling layer 12. This facilitates the pickup of the layer in the pickup step described later. The conditions for irradiating the laser beam 3 are not limited as long as they can cause interface erosion. A known laser beam irradiation device can be used for irradiation.

Finally, as shown in Figure 3(d), in the pickup step, the layer located at the location where interfacial erosion has occurred is picked up from the workpiece processing sheet 1 using a suction clamp 4 or the like. As described above, because a separation opportunity exists between the layer and the interfacial erosion layer 12, the layer can be easily picked up. While picking up the layer typically involves lifting it up from the back of the workpiece processing sheet 1 using a needle or the like, with the workpiece processing sheet 1 of this embodiment, this separation opportunity is already present, eliminating the need for such lifting and allowing for easy picking.

Furthermore, at any stage of the irradiation step and the pickup step, the workpiece processing sheet 1 can be expanded to separate the layers from each other.

The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit the present invention. Therefore, the elements disclosed in the embodiments described above also include all design changes, equivalents, etc. that fall within the technical scope of the present invention.

For example, another layer may be deposited between the interfacial peeling layer 12 and the substrate 13 in the workpiece processing sheet 1 of this embodiment, or on the surface of the substrate 13 opposite the interfacial peeling layer 12. A specific example of such another layer is an adhesive layer. In this case, the aforementioned separation step and the like can be performed while the surface of the substrate 13, which includes the adhesive layer, is attached to a support (a transparent substrate such as a glass plate). [Example]

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

[Preparation Example 1] (Adhesive Composition 1) 80 parts by mass of 2-ethylhexyl acrylate and 20 parts by mass of 2-hydroxyethyl acrylate were polymerized by solution polymerization to obtain an acrylic polymer. The weight-average molecular weight (Mw) of this acrylic polymer was measured by the method described below and was 600,000.

90.1 parts by mass of the acrylic polymer obtained above (solids content conversion, the same applies hereinafter), 0.9 parts by mass of trihydroxymethylpropane-modified methylenediisocyanate (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-acetic acid methyl)oxy-2-hydroxyphenyl}]-1,3,5-trisinium (a hydroxyphenyltrisinium-based UV absorber, manufactured by BASF, product name "Tinuvin 477") as an additive were mixed in a solvent to obtain a coating liquid of an adhesive composition. This adhesive composition was designated "Adhesive Composition 1."

The weight-average molecular weight (Mw) of the acrylic acid-based polymer is the polystyrene-equivalent weight-average molecular weight measured using gel permeation chromatography (GPC) under the following conditions (GPC measurement). <Measurement Conditions> GPC measurement apparatus: HLC-8320, manufactured by Tosoh Corporation GPC columns (used in the following order): TSK gel superH-H, manufactured by Tosoh Corporation TSK gel superHM-H, manufactured by Tosoh Corporation TSK gel superH2000 Measurement solvent: Tetrahydrofuran Measurement temperature: 40°C

[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)acrylate polymer. Furthermore, 2-methacryloyloxyethyl isocyanate (MOI) in an amount equivalent to 80 mol% of 2-hydroxyethyl acrylate constituting the (meth)acrylate polymer was reacted to obtain a (meth)acrylate polymer having active energy ray-curable groups introduced into the side chains (active energy ray-curable polymer). The weight average molecular weight of the active energy ray-curable polymer was measured by the aforementioned method and was found to be 1,000,000.

In a solvent, 81.6 parts by mass of the active energy ray-curable polymer obtained above, 2.1 parts by mass of trihydroxymethylpropane-modified phenylene diisocyanate (manufactured by Tosoh Corporation, trade name "CORONATE L") as a crosslinking agent, and 2-dimethylamino-2-(4-methylbenzyl)-1-(4- 16.3 parts by mass of 1,2-dimethoxy-1,4-diphenyl-1-oxo-1,4-dioxo-1,4-dopamine-1,4-dopamine-1-one (a photopolymerization initiator, manufactured by IGM Resins, product name "Omnirad 379") was added to obtain a coating liquid of an adhesive composition. This adhesive composition was designated "Adhesive Composition 2."

[Preparation Example 3] (Adhesive Composition 3)

In a solvent, 90.1 parts by mass of the active energy ray-curable polymer prepared in the same manner as in Preparation Example 2, 0.8 parts by mass of trihydroxymethylpropane-modified phenylene diisocyanate (manufactured by Tosoh Corporation, trade name "CORONATE L") as a crosslinking agent, and 9.0 parts by mass of bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide (photopolymerization initiator, manufactured by IGM Resins, product name "Omnirad 819") as an additive were mixed to obtain a coating liquid of an adhesive composition. This adhesive composition was designated "Adhesive Composition 3."

[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 (hereinafter referred to as "acrylic polymer (1)"). The weight average molecular weight (Mw) of this acrylic polymer (1) was measured by the aforementioned method and was found to be 800,000.

In methyl ethyl ketone as a solvent, 18 parts by mass of the acrylic polymer (1) obtained above, 40 parts by mass of an o-cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product name "EOCN-102S", epoxy equivalent 205-217 g/eq, softening point 55-77°C) as an epoxy resin, 10 parts by mass of a phenylmethane type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product name "EPPN-502H", epoxy equivalent 167 g/eq, softening point 54°C, molecular weight 1200) as an epoxy resin, and 10 parts by mass of an epoxy resin liquid bisphenol F type epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., product name "YL983U", epoxy equivalent 165~175g/eq) 6 parts by mass, o-cresol type phenolic resin as a heat curing agent (DIC Corporation, product name "PHENOLITE KA-1160", hydroxyl equivalent 117g/eq, softening point 80℃, n in general formula (1): 6~7) 24 parts by mass, 2-phenyl-4,5-dihydroxymethylimidazole as a curing accelerator (Shikoku Chemical Co., Ltd., product name "Curezol 0.3 parts by mass of "2PHZ-PW" (melting point 137-147°C), 1.0 parts by mass of an oligomeric silane coupling agent containing epoxy, methyl, and methoxy groups (Shin-Etsu Polysilicone Co., Ltd., product name "X-41-1056," epoxy equivalent weight 280 g/eq) as a coupling agent, and 0.7 parts by mass of trihydroxymethylpropane-methylenediisocyanate trimer adduct (Toyochem Co., Ltd., product name "BHS8515") as a crosslinking agent were added to obtain a coating liquid of an adhesive composition having a solid content concentration of 50% by mass. This adhesive composition is referred to as "Adhesive Composition 1."

[Preparation Example 5] (Adhesive Composition 2)

An acrylic polymer (hereinafter referred to as "acrylic polymer (2)") was obtained by polymerizing 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 by solution polymerization. The weight average molecular weight (Mw) of the acrylic polymer (2) was measured by the aforementioned method and was 800,000.

The same procedure as in Preparation Example 4 was followed, except that the acrylic polymer (2) prepared as described above was used instead of the acrylic polymer (1), to obtain a coating liquid of an adhesive composition. This adhesive composition is referred to as "Adhesive Composition 2".

[Preparation Example 6] (Adhesive Composition 3)

A coating liquid of an adhesive composition was obtained in the same manner as in Preparation Example 4, except that the blending amount of the aforementioned acrylic polymer (1) was changed to 17 parts by mass and 1 part by mass of an alkyl-aralkyl-modified polysilicone oil (produced by Momentive Performance Materials Japan, product name "XF42-334") was added as a general-purpose additive. This adhesive composition was designated "Adhesive Composition 3."

[Preparation Example 7] (Adhesive Composition 4)

The same procedure as in Preparation Example 4 was followed except that the blending amount of the aforementioned acrylic polymer (1) was changed to 15 parts by mass, 2.9 parts by mass of dicyclopentyl diacrylate (manufactured by Nippon Kayaku Co., Ltd., product name "KAYARAD R-684") as an active energy ray-curable resin was added, and 0.1 parts by mass of 2,2-dimethoxy-1,2-diphenylethane-1-one (manufactured by IGM Resins Co., Ltd., product name "Omnirad 651") as a photopolymerization initiator was added to obtain a coating liquid of an adhesive composition. This adhesive composition was designated "Adhesive Composition 4".

[Preparation Example 8] (Adhesive Composition 5) Except that the blending amount of the aforementioned acrylic polymer (1) was changed to 8 parts by mass, 9.7 parts by mass of dipentatriol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., product name "KAYARAD DPHA") as an active energy ray-curable resin was added, and 0.3 parts by mass of 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by IGM Resins Co., Ltd., product name "Omnirad 184") as a photopolymerization initiator was added, the same procedures as in Preparation Example 4 were followed to obtain a coating liquid of an adhesive composition. This adhesive composition was designated "Adhesive Composition 5".

[Example 1] (1) Formation of an interfacial peeling layer (adhesive layer) A peeling sheet (manufactured by LINTEC, product name "SP-PET381031") (hereinafter referred to as "peeling sheet A") having a polysilicone peeling layer formed on one side of a 38 μm thick polyethylene terephthalate film was coated with a coating liquid of the adhesive composition 1 obtained in Preparation Example 1, and the resulting coating film was dried by heating. In this way, a 5μm thick interfacial peeling layer (adhesive layer) and a laminate formed by peeling sheet A are obtained. The interfacial peeling layer (adhesive layer) is formed by coating and drying.

(2) Formation of Adhesive Layer A release sheet (manufactured by LINTEC, product name "SP-PET381031") (this release sheet is referred to as "release sheet B") having a silicone release layer formed on one side of a 38 μm thick polyethylene terephthalate film was coated with a coating liquid of Adhesive Composition 1 obtained in Preparation Example 4 and dried by heating at 100°C for 1 minute to form an adhesive layer having a thickness of 20 μm.

Next, the side of the formed adhesive layer opposite to Release Sheet B was laminated to the release surface of a release sheet (LINTEC, product name "SP-PET382150") (referred to as "Release Sheet C"), which had a silicone release layer formed on one side of a 38μm-thick polyethylene terephthalate film. This resulted in a laminate consisting of Release Sheet B, Adhesive Layer, and Release Sheet C layered in this order.

(3) Preparation of workpiece processing sheet The surface of the interfacial peeling layer in the laminate obtained in step (1) above is laminated to the single side (smooth side) of an 80 μm thick ethylene-methacrylic acid copolymer (EMMA) film as a substrate. Then, the peeling sheet A is peeled off to expose the interfacial peeling layer.

On the other hand, the peeling sheet C is peeled off from the laminate obtained in the above step (2), thereby exposing the adhesive layer. Then, the exposed surface of the adhesive layer is bonded to the exposed surface of the interface peeling layer exposed as described above, thereby obtaining a workpiece processing sheet formed by sequentially stacking the peeling sheet B, the adhesive layer, the interface peeling layer and the substrate.

[Examples 2-7] Except for changing the adhesive and adhesive compositions as shown in Table 1, the same procedures as in Example 1 were followed to obtain workpiece processing sheets.

[Comparative Example 1] The same procedure as step (2) of Example 1 was followed to obtain a laminated body formed by sequentially laminating a release sheet B, an adhesive layer, and a release sheet C. The release sheet C was then peeled off from the laminated body, and a single side (smooth side) of an ethylene methacrylate copolymer (EMMA) film having a thickness of 80 μm was adhered to the exposed surface of the adhesive layer. Thus, a workpiece processing sheet formed by sequentially laminating a release sheet B, an adhesive layer, and a substrate was obtained.

[Test Example 1] (1) Cutting The peeling sheet B was peeled off from the workpiece processing sheet produced by the embodiment and the comparative example, and the exposed surface of the adhesive layer was bonded to the polished surface of a silicon wafer (diameter 200mm, thickness 50μm) with a single-side polished surface of #2000 while being heated to 60°C using an adhesive bonding device (manufactured by LINTEC, product name "Adwill RAD2500"). Simultaneously with this bonding, a dicing jig, i.e., a ring frame, was bonded to the outer periphery of the silicon wafer on the exposed surface of the adhesive layer through a jig adhesive layer punched to the size of the ring frame.

Next, the silicon wafer and the adhesive layer were diced together using a dicing device (Disco, product name "DFD6361"). This yielded a plurality of thin-film adhesive-coated silicon wafers. These wafers were formed by laminating individual silicon wafers and adhesive layers of the same size.

The dicing was performed so that the silicon wafer, coated with a thin film of adhesive, had a planar size of 5 mm x 5 mm. The dicing blade's travel speed was set to 30 mm/s, and its rotational speed was set to 30,000 rpm. The dicing blade was continuously inserted until the remaining thickness of the workpiece reached 40 μm. The dicing blade used was the "Z05-SD2000-D1-90 CC" manufactured by Disco.

(2) Expansion and laser irradiation Next, a workpiece processing sheet formed by laminating a plurality of silicon wafers with a thin film adhesive was placed in a pickup/bonding device (manufactured by Canon Machinery, product name "BESTEM D-510") and the workpiece processing sheet was expanded in such a way that the expansion amount became 4 mm.

Then, while the wafer was still expanded, a laser irradiation device (Keyence, product name "MD-U1000C") was used to irradiate the interface stripping layer through the substrate. This irradiation was performed at each location on the silicon wafer where a thin film of adhesive was applied. This irradiation was repeated sequentially, covering a total of 100 locations on the silicon wafer where a thin film of adhesive was applied.

Specific irradiation conditions were as follows: a laser beam spot with a diameter of 25 μm was irradiated at the center of the wafer at a frequency of 40 kHz, a scanning speed of 500 mm/s, and an irradiation dose of 50 μJ/shot.

Furthermore, for Comparative Example 1 in which the workpiece processing wafer does not have an interface peeling layer, laser light irradiation is performed using the same settings and conditions as in Examples 1 to 7.

(3) Picking up and evaluating silicon wafers with thin film adhesive The wafers with thin film adhesive on them are picked up one by one using a suction clamp while the wafer is expanded. At this time, the wafers are lifted up from the back of the workpiece processing sheet without using a needle or the like.

The number of silicon wafers with film-coated adhesive that could be picked up was then evaluated for pickup performance based on the following criteria. The results are shown in Table 1. ◎…All 100 wafers could be picked up satisfactorily. ○…80 or more but less than 100 wafers could be picked up satisfactorily. △…50 or more but less than 80 wafers could be picked up satisfactorily. ×…Fewer than 50 wafers could be picked up, or wafers other than the target wafers were detached during pickup.

Furthermore, for the examples rated "◎," "○," and "△," the presence of adhesive residue was visually inspected at the location on the workpiece processing sheet where the thin film adhesive had been removed. The adhesive residue was then evaluated based on the following criteria. The results are shown in Table 1. ○...No adhesive residue was observed. ×...Adhesive residue was observed.

[Table 1] Types of adhesive compositions Type of adhesive composition Reviews Pickup Residue of the follow-up agent Example 1 Adhesive composition 1 Adhesive composition 1 ◎ ○ Example 2 Adhesive composition 2 Adhesive composition 1 ◎ ○ Example 3 Adhesive composition 1 Adhesive composition 2 ◎ ○ Example 4 Adhesive composition 1 Adhesive composition 3 ◎ ○ Example 5 Adhesive composition 1 Adhesive composition 4 ○ ○ Example 6 Adhesive composition 1 Adhesive composition 5 ○ ○ Example 7 Adhesive composition 3 Adhesive composition 1 △ ○ Comparative example 1 - Adhesive composition 1 × -

As can be seen from Table 1, the workpiece processing sheet produced according to the embodiment can successfully produce silicon wafers with a thin film adhesive. [Industrial Applicability]

The workpiece processing sheet of the present invention can be suitably used in the manufacture of semiconductor devices and the like.

1: Workpiece processing sheet 11: Adhesive layer 11': Thin film adhesive 12: Interfacial peeling layer 12': Reaction area 12'': Blistering 13: Substrate 2: Workpiece 2': Small workpiece 3: Laser beam 4: Adhesive cartridge

Figure 1 is a cross-sectional view of an example of a workpiece processing sheet according to one embodiment of the present invention. Figure 2 is a cross-sectional view of another example of a workpiece processing sheet according to one embodiment of the present invention. Figure 3 is a cross-sectional view illustrating a method for manufacturing a semiconductor device using a workpiece processing sheet according to one embodiment of the present invention.

1: Workpiece processing sheet

11: Next, the agent layer

12: Interface Erosion Layer

13: Base material

Claims (7)

A workpiece processing sheet is characterized by comprising: a substrate; an interface peeling layer deposited on one side of the substrate and capable of performing interface peeling by irradiation with laser light; and an adhesive layer deposited on the side of the interface peeling layer opposite to the substrate and composed of a curable film-like adhesive. The adhesive layer is formed from a composition containing at least one of a thermosetting component and an active energy ray-curable resin, wherein the thickness of the adhesive layer is greater than 1 μm and less than 30 μm. The interfacial peeling layer contains at least one additive selected from the group consisting of a UV absorber and a photopolymerization initiator, wherein the thickness of the interfacial peeling layer is greater than 3 μm and less than 100 μm. The workpiece processing sheet as described in claim 1, wherein the aforementioned interface peeling layer is an adhesive layer. The workpiece processing sheet as described in claim 1, wherein the laser light has a wavelength in the ultraviolet region. The workpiece processing sheet as claimed in claim 1, wherein when the interface etching layer is subjected to interface etching, blisters are formed at locations where the interface etching is caused. The workpiece processing sheet as described in claim 1 is used to separate the workpiece and the aforementioned adhesive layer together while the workpiece is maintained on the surface of the aforementioned adhesive layer opposite to the aforementioned interface peeling layer, thereby obtaining a plurality of layered integrals composed of small pieces of the aforementioned workpiece and small pieces of the aforementioned adhesive layer, and then selectively separate at least one of the layered integrals from the aforementioned interface peeling layer by locally generating interface peeling in the aforementioned interface peeling layer. A method for manufacturing a semiconductor device is characterized by comprising: a singulation step, in which the workpiece and the aforementioned adhesive layer are singulated together while the workpiece is maintained on the surface of the aforementioned adhesive layer side in the workpiece processing sheet as described in any one of claims 1 to 5, thereby obtaining a plurality of layer integrated by small pieces of the aforementioned workpiece and small pieces of the aforementioned adhesive layer; an irradiation step, in which laser light is irradiated to the position in the aforementioned interface peeling layer where at least one aforementioned layer integrated is maintained, thereby generating interface peeling at the aforementioned irradiated position in the aforementioned interface peeling layer; and a picking step, in which the aforementioned layer integrated at the position where the interface peeling has been generated is picked up from the aforementioned workpiece processing sheet. A use of a workpiece processing sheet, which is a use of the workpiece processing sheet as described in any one of claims 1 to 5 for manufacturing a semiconductor device, wherein the method for manufacturing the semiconductor device comprises: a singulation step, wherein the workpiece and the adhesive layer are singulated together while the workpiece is held on the surface of the adhesive layer side of the workpiece processing sheet, thereby obtaining a plurality of an integrated body composed of a small piece of the aforementioned workpiece and a small piece of the aforementioned adhesive layer; an irradiation step of irradiating a position in the aforementioned interface peeling layer where at least one of the aforementioned integrated bodies is retained with laser light, thereby generating interface peeling in the aforementioned irradiated position in the aforementioned interface peeling layer; and a picking step of picking up the aforementioned integrated body at the position where the interface peeling has been generated from the aforementioned workpiece processing sheet.