WO2022201766A1

WO2022201766A1 - Workpiece handling sheet and device manufacturing method

Info

Publication number: WO2022201766A1
Application number: PCT/JP2022/000964
Authority: WO
Inventors: 健太古野; 彰朗福元; 洋司若山; 喜章古川
Original assignee: リンテック株式会社
Priority date: 2021-03-26
Filing date: 2022-01-13
Publication date: 2022-09-29
Also published as: TW202239036A; CN116368003A; JP7325634B2; JPWO2022201766A1; KR20230161411A

Abstract

Provided is a workpiece handling sheet 1 comprising: a substrate 11; and an boundary surface ablation layer 12 which is laminated on one surface of the substrate 11 and which can hold small workpieces and perform boundary surface ablation by irradiation with a laser beam, wherein the boundary surface ablation layer 12 contains a photoinitiator, and the workpiece handling sheet has a 355 nm wavelength light ray absorbance of 1.5 or more. This workpiece handling sheet allows for proper handling even of very small workpieces.

Description

Work handling sheet and device manufacturing method

The present invention relates to a work handling sheet that can be used to handle small work pieces such as semiconductor components and semiconductor devices, and a device manufacturing method using the work handling sheet. (Micro Electro Mechanical Systems), etc., and a device manufacturing method using the work handling sheet.

In recent years, the development of displays using micro-light-emitting diodes has progressed. In such displays, individual pixels are composed of micro-light-emitting diodes, and the light emission of each micro-light-emitting diode is independently controlled. In the manufacture of such displays, it is generally necessary to mount micro-light-emitting diodes, which are arranged on a supply substrate such as sapphire, glass, etc., onto a wiring substrate provided with wiring.

During the mounting, it is necessary to accurately place the plurality of micro light-emitting diodes arranged on the supply board at predetermined positions on the wiring board. At this time, it is necessary to selectively mount a predetermined one of the plurality of micro light emitting diodes on the wiring board, or to mount a plurality of micro light emitting diodes at the same time.

From the viewpoint of performing such mounting well, the use of laser light irradiation is being considered. For example, after holding a plurality of micro light-emitting diodes on a support via a predetermined layer, by irradiating the layer with laser light, the layer is ablated at the irradiated position, thereby supporting the layer. A method of mounting a micro light-emitting diode separated from a body (laser lift-off) on a wiring board is being studied (Patent Document 1). Since the laser beam has excellent directivity and convergence, it is easy to control the irradiation position, and selective placement can be performed satisfactorily.

Patent No. 6546278

However, further miniaturization of micro light-emitting diodes and higher density mounting of micro light-emitting diodes are being promoted. There is a need for means that can handle fine work pieces such as micro light emitting diodes.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and provides a work handling sheet capable of handling even fine work piece pieces well, and a device manufacturing method using the work handling sheet. for the purpose.

In order to achieve the above object, firstly, the present invention provides a base material, and an interface ablation layer laminated on one side of the base material, capable of holding a small work piece, and ablating the interface by laser light irradiation. wherein the interfacial ablation layer contains a photopolymerization initiator, and the work handling sheet has an absorbance of 1.5 or more for light with a wavelength of 355 nm (Invention 1).

In the work handling sheet according to the above invention (invention 1), the interfacial abrasion layer contains a photopolymerization initiator, and the absorbance of light with a wavelength of 355 nm is in the above range, so that it is effective when irradiated with laser light. can be interfacially ablated so that the work pieces can be directed toward the object and have good separation.

In the above invention (Invention 1), the photopolymerization initiator preferably has an absorption peak in a wavelength range of 200 nm or more and 400 nm or less (Invention 2).

In the above inventions (inventions 1 and 2), the interface abrasion layer is preferably an adhesive layer (invention 3).

In the above invention (invention 3), the adhesive constituting the adhesive layer is preferably an active energy ray-curable adhesive (invention 4).

In the above inventions (inventions 3 and 4), the adhesive constituting the adhesive layer is preferably an acrylic adhesive (invention 5).

In the above inventions (Inventions 1 to 5), the laser light preferably has a wavelength in the ultraviolet region (Invention 6).

In the above inventions (inventions 1 to 6), when the interface ablation is caused in the interface ablation layer, blisters are preferably formed at the positions where the interface ablation occurs (invention 7).

In the above inventions (inventions 1 to 7), among the plurality of work pieces held on the surface of the interface ablation layer opposite to the base material by the interface ablation locally generated in the interface ablation layer (Invention 8).

In the above invention (Invention 8), the work pieces are obtained by singulating a work held on a surface of the interfacial ablation layer opposite to the base material into pieces on the surface. is preferred (invention 9).

In the above inventions (inventions 8 and 9), the work pieces are preferably at least one selected from semiconductor components and semiconductor devices (invention 10).

In the above inventions (inventions 8 to 10), the work pieces are preferably light emitting diodes selected from mini light emitting diodes and micro light emitting diodes (invention 11).

A second aspect of the present invention is a workpiece comprising a base material and an interfacial ablation layer containing a photopolymerization initiator laminated on one side of the base material, and having an absorbance of 1.5 or more for light with a wavelength of 355 nm. a preparation step of preparing a stack in which a plurality of work pieces are held on the surface of the handling sheet on the interface ablation layer side; an arranging step of arranging the laminate so that the surfaces of the small pieces face each other; and irradiating a laser beam to a position where at least one of the work pieces is attached in the interface ablation layer of the laminate, causing interfacial ablation at the irradiated location on the interfacial ablation layer to separate the work piece present at the location where the interfacial ablation occurred from the work handling sheet and place the work piece on the object; (Invention 12).

In the above invention (invention 12), in the preparation step, the workpiece held on the surface of the interfacial ablation layer opposite to the substrate is singulated on the surface to obtain the workpiece pieces. (Invention 13).

In the above inventions (inventions 12 and 13), the work pieces are preferably at least one selected from semiconductor components and semiconductor devices (invention 14).

In the above inventions (inventions 12 to 14), it is preferable to manufacture a light emitting device having a plurality of the light emitting diodes by using light emitting diodes selected from mini light emitting diodes and micro light emitting diodes as the work pieces (invention 15).

In the above invention (invention 15), the light-emitting device is preferably a display (invention 16).

The work handling sheet according to the present invention can handle even fine work pieces well, and according to the device manufacturing method according to the present invention, devices with excellent performance can be manufactured.

1 is a cross-sectional view of a work handling sheet according to one embodiment of the present invention; FIG. FIG. 4 is a cross-sectional view illustrating a device manufacturing method using a work handling sheet according to one embodiment of the present invention; FIG. 4 is a cross-sectional view illustrating the state of blisters and reaction regions generated by laser light irradiation.

Embodiments of the present invention will be described below.
FIG. 1 shows a cross-sectional view of a work handling sheet according to one embodiment. The work handling sheet 1 shown in FIG. 1 comprises a substrate 12 and an interfacial ablation layer 11 laminated on one side of the substrate 12 .

In the work handling sheet 1 according to this embodiment, the interface ablation layer 11 can hold small work pieces. That is, the work handling sheet 1 according to the present embodiment can hold the small work piece laminated on the surface of the interface ablation layer 11 opposite to the substrate 12 as it is.

Although the specific mode of holding is not limited, a preferable example is holding by the interface abrasion layer 11 demonstrating adhesiveness to the small piece of work. In this case, the interfacial ablation layer 11 preferably contains an adhesive as one of its constituent components, that is, is an adhesive layer, as will be described later.

Further, the interface ablation layer 11 in this embodiment is subjected to interface ablation by laser light irradiation. That is, the interface ablation layer 11 causes local interface ablation in the region irradiated with the laser beam. The laser light is not particularly limited as long as it can cause interfacial ablation, and may be a laser light having any wavelength in the ultraviolet region, the visible light region, and the infrared region. is preferred.

In this specification, interfacial ablation means that part of the components constituting the interfacial ablation layer 11 evaporates or volatilizes due to the energy of the laser beam, and the resulting gas is the interface between the interfacial ablation layer 11 and the substrate 12. It refers to the formation of air gaps (blister). In this case, the shape of the interfacial ablation layer 11 is changed by the blister, and the small work piece is peeled off from the interfacial ablation layer 11, resulting in separation of the work piece.

The interface ablation layer 11 in this embodiment contains a photopolymerization initiator, and the work handling sheet 1 in this embodiment has an absorbance of 1.5 or more for light with a wavelength of 355 nm. Thus, the presence of the photopolymerization initiator in the interfacial ablation layer 11 and the work handling sheet 1 exhibiting the absorbance described above improve the efficiency with which the interfacial ablation layer 11 receives energy from the laser beam. As a result, interface ablation occurs effectively, and the retained piece of work can be separated satisfactorily from the interface ablation layer 11 . In particular, the amount of laser light irradiation required to cause sufficient separation of the work pieces is reduced, the operating cost of the laser light irradiation device can be reduced, and only the target work pieces are easily separated. As a result, the accuracy is improved, and damage to the device or the like due to excessive laser beam irradiation can be prevented.

From the viewpoint of further improving the efficiency of receiving energy from laser light, the absorbance is preferably 2.0 or more, more preferably 2.2 or more, and particularly preferably 2.5 or more. , and more preferably 3.0 or more. The upper limit of the absorbance is not particularly limited, and may be 6.0 or less, for example. Further, the details of the method for measuring the absorbance are as described in the test examples described later.

1. Interfacial Ablation Layer The specific configuration and composition of the interfacial ablation layer 11 in the present embodiment is such that it can hold a small work piece, has the property of interfacial ablation by laser light irradiation, and contains a photopolymerization initiator. In addition, there is no particular limitation as long as the work handling sheet 1 can achieve the above-described absorbance.

From the point of view of easily exhibiting the property of being able to hold a small work piece, the interface abrasion layer 11 preferably contains an adhesive as one of its constituent components, as described above. When the interfacial abrasion layer 11 contains an adhesive, the interfacial abrasion layer 11 preferably comprises an adhesive composition containing a photopolymerization initiator.

(1) Photopolymerization Initiator The type of photopolymerization initiator in the present embodiment is not particularly limited. Examples of preferred photoinitiators include 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-phenyl)butan-1-one, ethanone, 1-[9-ethyl-6- (2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(0-acetyloxime), 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(O- benzoyloxime), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one It is preferred to use at least one.

Other photopolymerization initiators can be used together with the above photopolymerization initiators. Examples of photoinitiators that can be used together 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 -diphenylethan-1-one, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 4-(2-hydroxyethoxy ) phenyl-2-(hydroxy-2-propyl)ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-methylpropanone, benzophenone, p-phenylbenzophenone, 4,4′-diethylamino Benzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiary-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2 , 4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, oligo[2-hydroxy-2-methyl-1[4-(1-methylvinyl)phenyl]propanone], 2,4 , 6-trimethylbenzoyl-diphenyl-phosphine oxide and the like.

The photopolymerization initiator in the present embodiment preferably has an absorption peak in the wavelength range of 200 nm or more and 400 nm or less. As a result, the interface ablation layer 11 efficiently absorbs the laser light, thereby favorably facilitating interface ablation. From such a viewpoint, the lower limit of the above range is preferably 300 nm or more, and more preferably 330 nm or more. The upper limit of the above range is preferably 380 nm or less, more preferably 370 nm or less.

The above absorption peak can be specified based on the following method. First, a photopolymerization initiator is dissolved in methanol or acetonitrile as a solvent to prepare a measurement solution having a concentration of 0.01% by mass. Subsequently, the absorbance of the measurement solution is measured with a spectrophotometer (eg, “UV-3600” manufactured by Shimadzu Corporation) to obtain an absorption spectrum. Then, the wavelength range of the absorption peak (nm) can be specified from the obtained absorption spectrum.

Further, the photopolymerization initiator in the present embodiment preferably has an absorbance of 0.5 or more, particularly preferably 0.75 or more, at a wavelength of 355 nm in a solution having a concentration of 0.01% by mass. is preferably 1.0 or more. When the absorbance is 0.5 or more, the interface ablation layer 11 efficiently absorbs the laser light, thereby making it easier to perform interface ablation. The upper limit of the absorbance is not particularly limited, and may be, for example, 4.0 or less.

Incidentally, the above absorbance is obtained by preparing a methanol solution with a photopolymerization initiator concentration of 0.01% by mass (acetonitrile solution if the photopolymerization initiator is insoluble in methanol), and the wavelength range of 200 to 500 nm in the solution. was measured using an ultraviolet-visible-near-infrared (UV-Vis-NIR) spectrophotometer (manufactured by Shimadzu Corporation, product name "UV-3600", optical path length 10 mm).

The content of the photopolymerization initiator in the interface ablation layer 11 in the present embodiment is preferably 1.8% by mass or more, particularly preferably 3.0% by mass or more, and further preferably 5.0% by mass. % or more. When the content of the photopolymerization initiator is 1.8% by mass or more, the interface ablation layer 11 efficiently absorbs the laser light, thereby favorably facilitating interface ablation. Further, the content of the photopolymerization initiator in the interface ablation layer 11 in the present embodiment is preferably 40.0% by mass or less, particularly preferably 30.0% by mass or less, and further preferably 25.0% by mass or less. It is preferably 0% by mass or less. When the content of the photopolymerization initiator is 40.0% by mass or less, the viscosity of the material for forming the interfacial ablation layer 11 becomes appropriate, and it becomes easy to ensure good film formability.

Further, when the interfacial ablation layer 11 in the present embodiment is formed from an adhesive composition which will be described later, the photopolymerization initiator may be blended into this adhesive composition. In particular, when the photopolymerization initiator is blended in the adhesive composition together with the active energy ray-curable polymer (A) described later, the amount of the photopolymerization initiator in the adhesive composition is the active energy described later. It is preferably 1.8 parts by mass or more, particularly preferably 3.0 parts by mass or more, further preferably 5.0 parts by mass or more, relative to 100 parts by mass of the linear curable polymer (A). is preferred. When the blending amount of the photopolymerization initiator is 1.8 parts by mass or more, the interface ablation layer 11 efficiently absorbs the laser light, thereby making the interface ablation easier. The amount of the photopolymerization initiator in the adhesive composition is preferably 40.0 parts by mass or less, particularly 30.0 parts by mass, per 100 parts by mass of the active energy ray-curable polymer (A). It is preferably 0 parts by mass or less, more preferably 25.0 parts by mass or less. When the blending amount of the photopolymerization initiator is 40.0 parts by mass or less, the pressure-sensitive adhesive to be obtained easily exhibits desired pressure-sensitive adhesive strength.

(2) Adhesive As described above, the interface abrasion layer 11 in this embodiment may contain an adhesive in addition to the photopolymerization initiator. In this case, the interfacial abrasion layer 11 is preferably formed from an adhesive composition containing a photopolymerization initiator.

The adhesive is not particularly limited as long as it can exhibit sufficient holding power (adhesive power) to adherends such as small pieces of work. Examples of the adhesives include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, polyvinyl ether adhesives, and the like. Among these, it is preferable to use an acrylic pressure-sensitive adhesive from the viewpoint that it is easy to exhibit the desired adhesive strength.

In addition, although the adhesive may be an adhesive that does not have active energy ray-curability, an adhesive that has active energy ray-curability (hereinafter, may be referred to as an “active energy ray-curable adhesive”. ) is preferred. When the interfacial ablation layer 11 is composed of an active energy ray-curable adhesive, the interfacial ablation layer 11 is cured by irradiation with an active energy ray to easily reduce the adhesion of the work handling sheet 1 to the adherend. be able to.

In particular, the work pieces can be easily separated from the work handling sheet 1 by combining the decrease in adhesive strength due to the irradiation of the active energy ray with the interface abrasion described above. That is, before the interfacial abrasion described above occurs, or at the same time as the interfacial abrasion described above, the work pieces are separated from the work handling sheet 1 according to the present embodiment by reducing the adhesion by irradiating the active energy ray. This can be done more reliably. In addition, it is possible to further reduce the amount of laser light irradiation required to sufficiently separate the small work pieces.

The active energy ray-curable pressure-sensitive adhesive may be composed mainly of an active energy ray-curable polymer, or an active energy ray non-curable polymer (polymer not having active energy ray-curable). and a monomer and/or oligomer having at least one active energy ray-curable group. In addition, the active energy ray-curable pressure-sensitive adhesive may be a mixture of an active energy ray-curable polymer and a monomer and/or oligomer having at least one or more active energy ray-curable groups.

The active energy ray-curable polymer is a (meth)acrylic acid ester (co)polymer (A) (hereinafter referred to as It may be referred to as "active energy ray-curable polymer (A)"). This active energy ray-curable polymer (A) comprises an acrylic copolymer (a1) having a functional group-containing monomer unit and an unsaturated group-containing compound (a2) having a functional group that binds to the functional group. It is preferably obtained by reacting. In addition, in this specification, (meth)acrylic acid ester means both acrylic acid ester and methacrylic acid ester. The same applies to other similar terms. Furthermore, the term "polymer" shall also include the concept of "copolymer".

The acrylic copolymer (a1) preferably contains structural units derived from functional group-containing monomers and structural units derived from (meth)acrylate monomers or derivatives thereof.

The functional group-containing monomer as a structural unit of the acrylic copolymer (a1) has a polymerizable double bond and a functional group such as a hydroxy group, a carboxyl group, an amino group, a substituted amino group, an epoxy group, etc. in the molecule. is preferably a monomer having

Examples of hydroxy group-containing monomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl ( meth)acrylate, 4-hydroxybutyl (meth)acrylate and the like, and these may be used alone or in combination of two or more.

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

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

Examples of (meth)acrylic acid ester monomers constituting the acrylic copolymer (a1) include alkyl (meth)acrylates in which the alkyl group has 1 to 20 carbon atoms, and, for example, an alicyclic structure in the molecule. (alicyclic structure-containing monomer) is preferably used.

Examples of alkyl (meth)acrylates include alkyl (meth)acrylates in which the alkyl group has 1 to 18 carbon atoms, such as 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 individually by 1 type, and may be used in combination of 2 or more type.

Examples of alicyclic structure-containing monomers include cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, adamantyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentenyl (meth)acrylate. , dicyclopentenyloxyethyl (meth)acrylate and the like are preferably used. These may be used individually by 1 type, and may be used in combination of 2 or more type.

The acrylic copolymer (a1) preferably contains 1% by mass or more, particularly preferably 5% by mass or more, and still more preferably 10% by mass or more of the structural units derived from the functional group-containing monomer. In addition, the acrylic copolymer (a1) preferably contains 35% by mass or less, particularly preferably 30% by mass or less, and more preferably 25% by mass or less of structural units derived from the functional group-containing monomer. do.

Furthermore, the acrylic copolymer (a1) preferably contains 50% by mass or more, particularly preferably 60% by mass or more, more preferably 70% by mass of structural units derived from a (meth)acrylic acid ester monomer or derivative thereof. It is contained in the above ratio. In addition, the acrylic copolymer (a1) preferably contains 99% by mass or less, particularly preferably 95% by mass or less, and more preferably 90% by mass of structural units derived from a (meth)acrylic acid ester monomer or derivative thereof. Contained in the following proportions.

The acrylic copolymer (a1) can be obtained by conventionally copolymerizing a functional group-containing monomer as described above and a (meth)acrylic acid ester monomer or derivative thereof. Dimethylacrylamide, vinyl formate, vinyl acetate, styrene, and the like may be copolymerized.

The acrylic copolymer (a1) having a functional group-containing monomer unit is reacted with an unsaturated group-containing compound (a2) having a functional group that binds to the functional group to obtain an active energy ray-curable polymer ( A) is obtained.

The functional group of the unsaturated group-containing compound (a2) can be appropriately selected according to the type of functional group of the functional group-containing monomer unit of the acrylic copolymer (a1). For example, when the functional group possessed by the acrylic copolymer (a1) is a hydroxy group, an amino group or a substituted amino group, the functional group possessed by the unsaturated group-containing compound (a2) is preferably an isocyanate group or an epoxy group. When the functional group possessed by the system copolymer (a1) is an epoxy group, the functional group possessed by the unsaturated group-containing compound (a2) is preferably an amino group, a carboxyl group or an aziridinyl group.

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

The unsaturated group-containing compound (a2) is preferably 50 mol% or more, particularly preferably 60 mol% or more, and still more preferably 70 mol%, based on the number of moles of functional group-containing monomers in the acrylic copolymer (a1). % or more. In addition, the unsaturated group-containing compound (a2) is preferably 95 mol% or less, particularly preferably 93 mol% or less, and more preferably It is used in a proportion of 90 mol % or less.

In the reaction between the acrylic copolymer (a1) and the unsaturated group-containing compound (a2), the functional group of the acrylic copolymer (a1) and the functional group of the unsaturated group-containing compound (a2) Depending on the combination, reaction temperature, pressure, solvent, time, the presence or absence of a catalyst, and the type of catalyst can be appropriately selected. As a result, the functional groups present in the acrylic copolymer (a1) react with the functional groups in the unsaturated group-containing compound (a2), and the unsaturated groups in the acrylic copolymer (a1) It is introduced into the side chain to obtain an active energy ray-curable polymer (A).

The weight average molecular weight (Mw) of the active energy ray-curable polymer (A) thus obtained is preferably 10,000 or more, particularly preferably 50,000 or more, further preferably 100,000 or more. It is preferable to have Also, the weight average molecular weight (Mw) is preferably 3,000,000 or less, particularly preferably 2,000,000 or less, further preferably 1,500,000 or less. In addition, the weight average molecular weight (Mw) in this specification is the value of standard polystyrene conversion measured by the gel permeation chromatography method (GPC method).

Even when the active energy ray-curable pressure-sensitive adhesive contains a polymer having active energy ray-curable properties such as the active energy ray-curable polymer (A) as a main component, the active energy ray-curable pressure-sensitive adhesive is It may further contain curable monomers and/or oligomers (B).

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

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

When blending the active energy ray-curable monomer and/or oligomer (B) with the active energy ray-curable polymer (A), the active energy ray-curable monomer and/or in the active energy ray-curable pressure-sensitive adhesive Alternatively, the content of the oligomer (B) is preferably more than 0 parts by mass, particularly preferably 60 parts by mass or more, relative to 100 parts by mass of the active energy ray-curable polymer (A). The content is preferably 250 parts by mass or less, particularly preferably 200 parts by mass or less, relative to 100 parts by mass of the active energy ray-curable polymer (A).

Next, when the active energy ray-curable pressure-sensitive adhesive is mainly composed of a mixture of a non-active energy ray-curable polymer component and a monomer and/or oligomer having at least one active energy ray-curable group, It is explained below.

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

As the monomer and/or oligomer having at least one or more active energy ray-curable groups, the same ones as those for the component (B) described above can be selected. The blending ratio of the active energy ray non-curable polymer component and the monomer and/or oligomer having at least one active energy ray curable group is at least 1 per 100 parts by mass of the active energy ray non-curable polymer component. The monomer and/or oligomer having one or more active energy ray-curable groups is preferably 1 part by mass or more, particularly preferably 60 parts by mass or more. The compounding ratio is preferably 200 parts by mass or less of monomers and/or oligomers having at least one active energy ray-curable group per 100 parts by mass of the active energy ray non-curable polymer component, In particular, it is preferably 160 parts by mass or less.

(3) Other Components The adhesive composition described above may optionally contain other components. Other components include, for example, an active energy ray non-curable polymer component or oligomer component (D), a cross-linking agent (E), and the like.

Examples of the active energy ray non-curable polymer component or oligomer component (D) include polyacrylates, polyesters, polyurethanes, polycarbonates, polyolefins, etc., and polymers or polymers having a weight average molecular weight (Mw) of 3000 to 2.5 million. Oligomers are preferred. By adding the component (D) to the energy ray-curable pressure-sensitive adhesive, it is possible to improve the adhesiveness and peelability before curing, the strength after curing, the adhesion to other layers, storage stability, and the like. The blending amount of the component (D) is not particularly limited, and is appropriately determined in the range of more than 0 parts by mass and 50 parts by mass or less with respect to 100 parts by mass of the energy ray-curable copolymer (A).

The use of the cross-linking agent (E) is preferable from the viewpoint of facilitating adjustment of the storage elastic modulus of the interfacial ablation layer 11 to a desired range. As the cross-linking agent (E), a polyfunctional compound having reactivity with the functional groups of the active energy ray-curable copolymer (A) or the like can be used. Examples of such polyfunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts, Reactive phenol resin etc. can be mentioned.

The amount of the cross-linking agent (E) is preferably 0.001 parts by mass or more, particularly 0.1 parts by mass or more, relative to 100 parts by mass of the active energy ray-curable copolymer (A). is preferred, and 0.2 parts by mass or more is preferred. In addition, the amount of the cross-linking agent (E) is preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less, relative to 100 parts by mass of the active energy ray-curable copolymer (A). , and more preferably 5 parts by mass or less.

Other components that can be blended into the adhesive composition include tackifiers, coloring materials such as dyes and pigments, flame retardants, fillers, and additives such as antistatic agents. The adhesive composition preferably does not contain a gas generating agent from the viewpoint that the work pieces are easily separated. The use of a gas generating agent may generate gas across the interfacial ablation layer 11 . In that case, it may be difficult to cause interface abrasion only at an intended position to separate only the small work pieces located there, and it may be difficult to separate the small work pieces satisfactorily.

(4) Thickness of interface ablation layer The thickness of the interface ablation layer 11 in the present embodiment is preferably 3 μm or more, particularly preferably 20 μm or more, further preferably 25 μm or more. Further, the thickness of the interfacial ablation layer 11 is preferably 100 μm or less, particularly preferably 50 μm or less, further preferably 40 μm or less. When the thickness of the interfacial ablation layer 11 is within the above range, both holding of the work piece on the interfacial ablation layer 11 and separation of the work piece by interfacial abrasion can be easily achieved.

2. Substrate The composition and physical properties of the substrate 12 in the present embodiment are not particularly limited. From the viewpoint that the work handling sheet 1 can easily exhibit the desired functions, the base material 12 is preferably made of resin. When the base material 12 is made of a resin, examples of the resin include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, and ethylene-norbornene. Polymer, polyolefin resin such as norbornene resin; ethylene-vinyl acetate copolymer; ethylene-(meth)acrylic acid copolymer, ethylene-(meth)methyl acrylate copolymer, other ethylene-(meth)acryl Ethylene-based copolymer resins such as acid ester copolymers; polyvinyl chloride-based resins such as polyvinyl chloride and vinyl chloride copolymers; (meth)acrylic acid ester copolymers; polyurethanes; polyimides; etc. Further, the resin constituting the base material 12 may be a crosslinked resin or a modified ionomer of the above resin. Further, the substrate 12 may be a single-layer film made of the resin described above, or may be a laminated film formed by laminating a plurality of such films. In this laminated film, the materials constituting each layer may be of the same type or of different types.

The surface of the substrate 12 in this embodiment may be subjected to a surface treatment such as an oxidation method or a roughening method, or a primer treatment for the purpose of improving adhesion to the interface ablation layer 11 . Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment. A thermal spraying method and the like can be mentioned.

The base material 12 in this embodiment may contain various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, and fillers. Moreover, when the interfacial ablation layer 11 contains a material that is cured by active energy rays, the substrate 12 preferably has transparency to active energy rays.

The manufacturing method of the base material 12 in this embodiment is not particularly limited as long as the base material 12 is manufactured from resin. For example, it can be produced by forming a resin into a sheet by a melt extrusion method such as a T-die method or a round die method; a calendering method; or a solution method such as a dry method or a wet method.

The thickness of the base material 12 in this embodiment is preferably 10 μm or more, particularly preferably 30 μm or more, further preferably 50 μm or more. The thickness of the base material 12 is preferably 500 μm or less, more preferably 300 μm or less, particularly preferably 200 μm or less, further preferably 150 μm or less, and 100 μm or less. is most preferred. When the thickness of the base material 12 is within the above range, the work handling sheet 1 has rigidity and flexibility in a predetermined balance, and the small work piece can be easily handled well.

3. Release sheet In the present embodiment, when the interfacial abrasion layer 11 contains an adhesive as one of its constituent components, the surface of the interfacial abrasion layer 11 opposite to the substrate 12 is adhered to the work piece. For the purpose of protecting the surface, a release sheet may be laminated on the surface.

The configuration of the release sheet is arbitrary, and examples thereof include plastic films that have undergone a release treatment using a release agent or the like. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, a silicone-based release agent, a fluorine-based release agent, a long-chain alkyl-based release agent, or the like can be used.

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

4. Other Configurations In the work handling sheet 1 according to the present embodiment, an adhesive layer may be laminated on the surface of the interface abrasion layer 11 opposite to the substrate 12 . In the sheet, a workpiece is attached to the surface of the adhesive layer opposite to the surface ablation layer 11, and the adhesive layer is diced together with the workpiece to form workpiece pieces in which the individualized adhesive layers are laminated. can be obtained. The chip can be easily fixed to the object on which the work piece is mounted by the individualized adhesive layer. Examples of the material constituting the adhesive layer include those containing a thermoplastic resin and a low-molecular-weight thermosetting adhesive component, those containing a B-stage (semi-cured) thermosetting adhesive component, and the like. It is preferable to use

In addition, in the work handling sheet 1 according to the present embodiment, a protective film-forming layer may be laminated on the surface of the interface abrasion layer 11 opposite to the substrate 12 . In such a sheet, a work is attached to the surface of the protective film-forming layer opposite to the surface of the protective film-forming layer 11, and the protective film-forming layer is diced together with the work. A laminated work piece can be obtained. As the work, one having a circuit formed on one side is preferably used. In this case, a protective film-forming layer is usually laminated on the side opposite to the side on which the circuit is formed. By curing the individualized protective film-forming layer at a predetermined timing, a protective film having sufficient durability can be formed on the work pieces. The protective film-forming layer is preferably made of an uncured curable adhesive.

5. Physical properties of the work handling sheet In the work handling sheet 1 according to the present embodiment, the adhesive force to the mirror surface of the silicon wafer is preferably 10 mN/25 mm or more, particularly preferably 100 mN/25 mm or more, and further preferably 200 mN. /25 mm or more. When the adhesive strength is 10 mN/25 mm or more, an adherend such as a small piece of work can be easily fixed to the work handling sheet 1, resulting in excellent handling properties. The adhesive strength is preferably 30000 mN/25 mm or less, particularly preferably 15000 mN/25 mm or less, and more preferably 10000 mN/25 mm or less. When the adhesive strength is 30,000 mN/25 mm or less, it becomes easier to separate the work pieces by laser light irradiation.

Further, when the interfacial abrasion layer 11 in the present embodiment is an adhesive layer composed of the active energy ray-curable adhesive described above, it is preferable that the adhesive strength after ultraviolet irradiation satisfies the following conditions. That is, the surface of the interfacial ablation layer 11 opposite to the base material 12 is attached to the mirror surface of a silicon wafer, and the interfacial ablation layer 11 is cured by irradiating the interfacial ablation layer 11 with ultraviolet rays using a high-pressure mercury lamp. The adhesive force to the mirror surface of the silicon wafer after the application is preferably 2000 mN/25 mm or less, particularly preferably 1000 mN/25 mm or less, further preferably 200 mN/25 mm or less. When the adhesive force is 2000 mN/25 mm or less, it becomes easier to separate the small work pieces by subsequent interfacial abrasion. The lower limit of the adhesive strength is not particularly limited, and may be, for example, 5 mN/25 mm or more, particularly 10 mN/25 mm or more, and further 20 mN/25 mm or more.

The details of the method for measuring these adhesive strengths are as described in the test examples described later.

6. Method for Manufacturing Work Handling Sheet A method for manufacturing the work handling sheet 1 according to the present embodiment is not particularly limited. For example, the interfacial ablation layer 11 may be directly formed on the base material 12, or the interfacial ablation layer 11 may be formed on the process sheet and then transferred onto the base material 12. .

When the interfacial ablation layer 11 contains an adhesive as one of its constituent components, the interfacial ablation layer 11 can be formed by a known method. For example, a coating liquid containing an adhesive composition for forming the interfacial ablation layer 11 and optionally a solvent or dispersion medium is prepared. Then, the above coating liquid is applied to one side of the base material or the releasable side of the release sheet (hereinafter sometimes referred to as "release side"). Subsequently, by drying the obtained coating film, the interfacial abrasion layer 11 can be formed.

The application of the coating liquid described above can be performed by a known method, for example, bar coating, knife coating, roll coating, blade coating, die coating, gravure coating, or the like. The properties of the coating liquid are not particularly limited as long as it is possible to apply the coating liquid. be. Further, when the interface abrasion layer 11 is formed on the release sheet, the release sheet may be peeled off as a process material, or may protect the interface abrasion layer 11 until it is attached to the adherend. .

When the adhesive composition for forming the interfacial ablation layer 11 contains the above-described cross-linking agent, by changing the drying conditions (temperature, time, etc.) or by separately providing heat treatment, It is preferable to promote a cross-linking reaction between the polymer component in the coating film and the cross-linking agent to form a cross-linked structure with a desired existence density in the interfacial ablation layer 11 . Furthermore, in order to allow the cross-linking reaction to proceed sufficiently, after the work handling sheet 1 is completed, it may be cured by leaving it in an environment of, for example, 23° C. and a relative humidity of 50% for several days.

7. Method of Using Work Handling Sheet The work handling sheet 1 according to this embodiment can be suitably used for handling small pieces of work. As described above, in the work handling sheet 1 according to the present embodiment, the interface ablation layer 11 is efficiently ablated by laser light irradiation. It can be separated towards a predetermined position with precision.

As an example of the method of using the work handling sheet 1 according to the present embodiment, the surface of the interface ablation layer 11 is held on the surface opposite to the substrate 12 by the interface ablation locally caused in the interface ablation layer 11. A method of use is to selectively separate an arbitrary work piece out of a plurality of work pieces from the interfacial ablation layer 11 .

In the method of use described above, the plurality of work pieces held on the interfacial ablation layer 11 are the works (materials of the work pieces) held on the surface of the interfacial ablation layer 11 opposite to the substrate 12 . It may be obtained by singulating on the surface. That is, the work piece may be obtained by dicing the work on the interface ablation layer 11 . Alternatively, the small work piece may be formed independently of the work handling sheet 1 according to the present embodiment and placed on the interfacial ablation layer 11 .

In addition, when the work handling sheet 1 according to the present embodiment includes the adhesive layer and the protective film forming layer described above, it is preferable to dice these layers and the work on the interface ablation layer 11 . As a result, it is possible to obtain workpiece pieces in which these layers are separated into individual pieces and laminated.

Although the shape and size of the work piece in the present embodiment are not particularly limited, the work piece preferably has an area of 10 μm ² or more, particularly 100 μm ² or more, when viewed from above. In addition, the work piece preferably has an area of 1 mm ² or less, particularly preferably 0.25 mm ² or less when viewed from above. As for the size of the work piece, when the work piece is rectangular, the minimum side of the work piece is preferably 2 μm or more, particularly preferably 5 μm or more, and further preferably 10 μm or more. preferable. Moreover, the minimum side is preferably 1 mm or less, and particularly preferably 0.5 mm or less. Specific examples of the dimensions of the rectangular work piece include 2 μm×5 μm, 10 μm×10 μm, 0.5 mm×0.5 mm, 1 mm×1 mm, and the like. The work handling sheet 1 according to the present embodiment can satisfactorily handle such fine work pieces, especially fine work pieces that are difficult to separate from the sheet by pushing up a needle. On the other hand, the work handling sheet 1 according to the present embodiment has a relatively large area, such as one having an area exceeding 1 mm ² (for example, 1 mm ² to 2,000 mm ² ) or having a thickness of 1 to 10,000 μm (for example, 10 to 1,000 μm). Work piece pieces of any size can also be handled well.

Examples of small work pieces include semiconductor parts and semiconductor devices, and more specifically, micro light-emitting diodes, power devices, MEMS (Micro Electro Mechanical Systems), and the like. Among these, the work pieces are preferably light emitting diodes, and particularly preferably light emitting diodes selected from mini light emitting diodes and micro light emitting diodes. In recent years, the development of devices in which mini light emitting diodes and micro light emitting diodes are densely arranged has been studied. is very suitable.

As a specific usage example of the work handling sheet 1, a device manufacturing method will be described below with reference to FIG. The device manufacturing method includes at least three steps: a preparation step (FIG. 2(a)), an arrangement step (FIG. 2(b)), and a separation step (FIGS. 2(c) and (d)).

In the preparation step, as shown in FIG. 2A, a laminate is prepared in which a plurality of small work pieces 2 are held on the surface of the work handling sheet 1 according to the present embodiment on the side of the interface ablation layer 11. . The laminate may be prepared by placing a separately prepared work piece 2 on the work handling sheet 1, or a work held on the surface of the interfacial ablation layer 11 side may be individually placed on the surface. It may be prepared by dicing (ie, dicing). The dicing can be performed by a known method.

The shape and size of the work piece 2 are not particularly limited as described above, and the preferred size is also as described above. Specific examples of the workpiece 2 also include, as described above, semiconductor components and semiconductor devices, and particularly light-emitting diodes such as mini light-emitting diodes and micro light-emitting diodes.

In the subsequent arranging step, as shown in FIG. 2B, the laminate is arranged so that the surface of the laminate on the side of the small work piece 2 faces the object 3 that can receive the small work piece 2. . Examples of the object 3 are appropriately determined according to the device to be manufactured. In particular, a wiring substrate provided with wiring is preferably used.

After that, in the separation step, first, as shown in FIG. 2(c), a laser beam is irradiated to the position where at least one work piece 2 is attached in the interface ablation layer 11 in the laminate. The irradiation may be performed simultaneously on a plurality of positions where the work pieces 2 are attached, or may be performed sequentially on those positions. The irradiation conditions of the laser light are not limited as long as it is possible to cause interfacial ablation. As a device for irradiation, a known device can be used.

The irradiation can cause interfacial ablation at the irradiated position in the interfacial ablation layer 11, as shown in FIG. 2(d). Specifically, the irradiation of the laser light evaporates or volatilizes the components forming the region in the interface ablation layer 11 in the vicinity of the base material 12 to form the reaction region 13 . Then, the gas generated by the evaporation or volatilization accumulates between the substrate 11 and the reaction area 13 to form a blister 5 . Due to the formation of the blisters 5 , the interfacial ablation layer 11 is locally deformed at the position of the work piece 2 ′, and the work piece 2 ′ separates so as to be peeled off from the interfacial ablation layer 11 . As described above, the work piece 2 ′ existing at the position where the interface abrasion has occurred can be placed on the object 3 .

Note that the reaction region 13 and the blisters 5 generated by the irradiation of the laser light usually remain even after the work pieces 2' are separated. FIG. 3 shows how the work pieces 2 are separated by sequentially irradiating laser light. The previous states (right two) are shown. As shown, the blister 5 after detachment is typically in a slightly more deflated state than the blister 5 during detachment.

When the interfacial abrasion layer 11 in the present embodiment is an adhesive layer composed of the active energy ray-curable adhesive described above, the device manufacturing method described above may further include the following curing step. . That is, for the entire interfacial ablation layer 11 in a laminate in which a plurality of work pieces 2 are held on the surface on the interfacial ablation layer 11 side, or at least one work piece in the interfacial ablation layer 11 in the laminate A curing step may be provided for curing the interfacial ablation layer 11 entirely or locally by irradiating the position where 2 is attached with an active energy ray. This curing step may be performed prior to the separation step described above, or may be performed simultaneously with the separation step described above.

As described above, by curing the interfacial ablation layer 11 wholly or locally by irradiation with active energy rays, the adhesion of the work handling sheet 1 to the work piece 2 can be reduced, and interfacial abrasion occurs. 2, it becomes easy to separate the small work piece 2 satisfactorily. Irradiation of active energy rays in the curing step may be performed using a known technique, for example, an ultraviolet irradiation device equipped with a high-pressure mercury lamp or an ultraviolet LED as a light source, or a laser light irradiation device used in the separation step. may When the curing process and the separation process are performed simultaneously, it is preferable to perform the irradiation with the laser light 4 using the laser light irradiation device in combination with the irradiation with the active energy ray.

The device manufacturing method described above may include processes other than the preparation process, placement process, curing process, and separation process. For example, grinding, die bonding, wire bonding, molding, inspection, transfer process, etc. may be performed at any timing between the preparation process and the separation process.

According to the device manufacturing method described above, various devices can be manufactured by appropriately selecting the work piece 2 and the target object 3 to be used. For example, when a light emitting diode selected from mini light emitting diodes and micro light emitting diodes is used as the work piece 2, a light emitting device comprising a plurality of such light emitting diodes can be manufactured, more specifically a display can be manufactured. In particular, it is possible to produce displays with micro LEDs as pixels and displays with a plurality of mini LEDs as backlight.

In addition, the work handling sheet 1 according to this embodiment can also be used for a method of selectively removing a predetermined small work piece 2 out of a plurality of small work pieces 2 provided on the sheet.

For example, after manufacturing a plurality of light-emitting diodes on the work handling sheet 1 according to this embodiment, the light-emitting diodes are inspected on the sheet. Therefore, only the light emitting diodes confirmed to be defective can be detached and removed from the work handling sheet 1 by causing interface abrasion.

Furthermore, it is also possible to transfer the set of good products from the work handling sheet 1 to the shipping sheet. At this time, when the interfacial ablation layer 11 is composed of the active energy ray-curable adhesive described above, by irradiating the interfacial ablation layer 11 with an active energy ray, the light emitting diodes of the work handling sheet 1 Adhesion can be reduced to allow good transfer of a set of good products to a shipping sheet. After that, by rearranging a separately manufactured non-defective product in the position where the defective product has been removed, it is possible to obtain the work handling sheet 1 on which only the non-defective product is provided.

With the above method of removing defective products by interfacial ablation, there is no need to expand the sheet or pick up defective products, so it is difficult to change the spacing of the light-emitting diodes or cause misalignment. As a result, it can be easily and satisfactorily transferred to the shipping sheet.

The embodiments described above are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiments is meant to include all design changes and equivalents that fall within the technical scope of the present invention.

For example, another layer is laminated between the interfacial ablation layer 11 and the base material 12 in the work handling sheet 1 according to the present embodiment, or on the surface of the base material 12 opposite to the interfacial ablation layer 11. good too. A specific example of the other layer is an adhesive layer. In this case, the above-described separation step and the like can be performed in a state in which the adhesive layer side surface is adhered to a support base (a transparent substrate such as a glass plate).

The adhesive that constitutes the adhesive layer is not particularly limited, but one that is difficult to absorb active energy rays and difficult to block active energy rays is preferable. In this case, when a laser beam is irradiated through the pressure-sensitive adhesive layer, the laser beam can easily reach the interface abrasion layer 11, and good interface abrasion can easily occur. Specifically, as the adhesive constituting the adhesive layer, it is preferable to use an adhesive that does not have active energy ray-curable properties, and in particular, an adhesive that does not contain an active energy ray-curable component is preferably used. preferable. By using an adhesive that does not have active energy ray curability, the adhesive layer does not harden even when irradiated with the laser beam, thereby making the work handling sheet 1 from a transparent substrate. It is also possible to prevent peeling that does not occur. Although the thickness of the pressure-sensitive adhesive layer is not particularly limited, it is preferably 5 to 50 μm, for example.

Although the present invention will be described in more detail with reference to examples and the like, the scope of the present invention is not limited to these examples and the like.

[Example 1]
(1) Preparation of Adhesive Composition 70 parts by mass of 2-ethylhexyl acrylate and 30 parts by mass of 2-hydroxyethyl acrylate were polymerized by a solution polymerization method to obtain a (meth)acrylate polymer. . This (meth)acrylic acid ester polymer is reacted with 90 mol % of methacryloyloxyethyl isocyanate (MOI) with respect to 2-hydroxyethyl acrylate to introduce an active energy ray-curable group into the side chain. A (meth)acrylic acid ester copolymer (active energy ray-curable polymer (A)) was thus obtained. When the weight average molecular weight (Mw) of this active energy ray-curable polymer (A) was measured by the method described above, it was 800,000.

100 parts by mass of the active energy ray-curable polymer (A) obtained above (in terms of solid content, hereinafter the same), and trimethylolpropane-modified tolylene diisocyanate (manufactured by Tosoh Corporation, trade name “Coronate L”) as a cross-linking agent ”) 2.5 parts by mass and ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(0-acetyloxime as a photopolymerization initiator ) (manufactured by BASF, product name “Irugacure OXE02”) and 4 parts by mass were mixed in a solvent to obtain a coating liquid of an adhesive composition having a solid content concentration of 30% by mass.

(2) Preparation of work handling sheet As a base material, the above-mentioned The coating liquid of the adhesive composition obtained in step (1) was applied, and the obtained coating film was dried by heating. As a result, an interfacial abrasion layer (adhesive layer) having a thickness of 30 μm was formed on the substrate.

Subsequently, a release sheet (manufactured by Lintec Corporation, product name "SP- PET381031”) was bonded to the release surface. As a result, a work handling sheet was obtained in which the release sheet, the interfacial abrasion layer and the substrate were laminated in this order.

(3) Measurement method of weight average molecular weight The weight average molecular weight (Mw) described above is a weight average molecular weight in terms of standard polystyrene measured using gel permeation chromatography (GPC) under the following conditions (GPC measurement).
<Measurement conditions>
・ Measuring device: HLC-8320 manufactured by Tosoh Corporation
・ GPC column (passed in the following order): TSK gel superH-H manufactured by Tosoh Corporation
TSK gel super HM-H
TSK gel super H2000
・Measurement solvent: tetrahydrofuran ・Measurement temperature: 40°C

[Examples 2-3 and Comparative Examples 1-3]
A work handling sheet was produced in the same manner as in Example 1, except that the type and content of the photopolymerization initiator were changed as shown in Table 1. Comparative Example 1 is an example in which no photopolymerization initiator was used.

[Test Example 1] (Measurement of UV absorbance)
The release sheets were peeled off from the work handling sheets produced in Examples and Comparative Examples to expose the interfacial ablation layer. For this work handling sheet, an ultraviolet / visible / near-infrared spectrophotometer (manufactured by Shimadzu Corporation, product name "UV-3600") and an attached large sample chamber (manufactured by Shimadzu Corporation, product name "MPC-3100" ) was used to measure the UV absorbance. The measurement was performed by using an integrating sphere built into the large sample chamber and irradiating a light beam with a wavelength of 355 nm with a slit width of 20 nm toward the surface on the interface ablation layer side. Table 1 shows the results.

[Test Example 2] (Measurement of adhesive strength)
The work handling sheets produced in Examples and Comparative Examples were cut into strips with a width of 25 mm. The release sheet was peeled off from the obtained strip-shaped work handling sheet, and the exposed surface of the exposed interface abrasion layer was placed against the mirror surface (mirror surface) of the mirror-finished silicon wafer at a temperature of 23 ° C. and a relative humidity. It was applied using a 2 kg rubber roller under an environment of 50%, and allowed to stand for 20 minutes to obtain a sample for adhesive strength measurement.

After that, using a universal tensile tester (manufactured by Orientec, product name "Tensilon UTM-4-100"), the work handling sheet was peeled from the silicon wafer at a peeling speed of 300 mm / min and a peeling angle of 180 °, and JIS Adhesion (mN/25 mm) to the mirror surface of the silicon wafer was measured by the 180° peeling method according to Z0237:2009. The results are shown in Table 1 as adhesive strength before ultraviolet irradiation.

In addition, an ultraviolet irradiation device equipped with a high-pressure mercury lamp as a light source (manufactured by Lintec Co., Ltd., product name "RAD-2000") was applied to the interface ablation layer in the sample for adhesion measurement obtained in the same manner as above, through the substrate. was used to irradiate ultraviolet rays (illuminance: 230 mW/cm ² , light intensity: 190 mJ/cm ² ) to cure the interface abrasion layer. Adhesive force (mN/25 mm) to the mirror surface of the silicon wafer was measured in the same manner as described above for this sample for adhesive force measurement after UV irradiation. The results are shown in Table 1 as adhesive strength after UV irradiation.

[Test Example 3] (Evaluation of suitability for laser lift-off)
(1) Chip preparation on work handling sheet (preparation process)
An adhesive surface of a dicing sheet (manufactured by Lintec, product name “D-485H”) was attached to one side of a silicon wafer (#2000, thickness: 350 μm). Subsequently, a ring frame for dicing was adhered to the periphery of the adhesive surface of the dicing sheet (the position not overlapping the silicon wafer). Furthermore, the dicing sheet was cut according to the outer diameter of the ring frame. Thereafter, the silicon wafer was diced into chips having a size of 300 μm×300 μm using a dicing machine (manufactured by Disco, product name “DFD6362”). After that, the dicing sheet was irradiated with ultraviolet light (illuminance: 230 mW/cm ² , light amount: 190 mJ/cm ² ). As a result, a laminate having a plurality of chips provided on the dicing sheet was obtained.

Subsequently, the release sheet was peeled off from the work handling sheets produced in Examples and Comparative Examples, and the exposed surface thus exposed was bonded to the surface on which the plurality of chips of the laminate obtained as described above existed. . After that, the dicing sheet was peeled off from the plurality of chips. As a result, a plurality of chips were transferred from the dicing sheet to the work handling sheet to obtain a laminate having a plurality of chips provided on the work handling sheet.

(2) Separation of chips by laser light irradiation (separation process)
For the laminate obtained in the above step (1), in which a plurality of chips are provided on the work handling sheet, the chips were irradiated with laser light through the work handling sheet using a laser light irradiation device. .

Specifically, the chip was irradiated with a laser beam with a wavelength of 355 nm through the work handling sheet using a laser beam irradiation device (manufactured by Keyence Corporation, product name "MD-U1000C"). The irradiation was performed by sequentially irradiating the center of the chip with a laser light spot so as to draw a circle. At this time, the diameter of the laser beam spot was set to 25 μm, and the inner diameter of the ring formed as the locus of irradiation was set to 65 μm. Other irradiation conditions were frequency: 40 kHz, scan speed: 500 mm/s, and irradiation amount: 50 μJ/shot. Also, 100 chips (a group of 10 chips in the vertical direction×10 chips in the horizontal direction) were selected from a plurality of chips and irradiated.

(3) Confirmation of blisters and chip separation Regarding the work handling sheet and chips irradiated as described above, the presence or absence of blisters at the interface between the base material and the interface ablation layer in the work handling sheet, and the separation of chips from the work handling sheet. The presence or absence of detachment was confirmed, and suitability for laser lift-off was evaluated based on the following criteria. Table 1 shows the results.
A: Blisters occurred at all 100 tips, and all 100 tips were detached.
◯: The number of chips on which blister formation and detachment occurred was 80 or more and less than 100.
x: The number of chips with blistering and detachment was less than 80.

Details of abbreviations and the like in Table 1 are as follows.
IrugacureOXE02: Ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(0-acetyloxime) (manufactured by BASF, product name "IrugacureOXE02")
Omnirad379: 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-phenyl)butan-1-one (manufactured by IGM Resins, product name “Omnirad379”)
Omnirad651: 2,2-dimethoxy-1,2-diphenylethan-1-one (manufactured by IGM Resins, product name “Omnirad651”)

As is clear from Table 1, the work handling sheets produced in Examples were excellent in suitability for laser lift-off.

The work handling sheet of the present invention can be suitably used for manufacturing a display or the like having micro light-emitting diodes as pixels.

REFERENCE SIGNS LIST 1 work handling sheet 11 interface ablation layer 12 substrate 13 reaction regions 2, 2' work piece 3 object 4 laser beam 5 blister 6 laser beam irradiation point

Claims

a substrate;
A work handling sheet comprising an interfacial ablation layer laminated on one side of the base material, capable of holding a small work piece, and performing interfacial ablation by irradiation with a laser beam,
the interfacial ablation layer contains a photopolymerization initiator,
A work handling sheet, wherein the work handling sheet has an absorbance of 1.5 or more for light having a wavelength of 355 nm.
The work handling sheet according to claim 1, wherein the photopolymerization initiator has an absorption peak in a wavelength range of 200 nm or more and 400 nm or less.
The work handling sheet according to claim 1 or 2, wherein the interfacial abrasion layer is an adhesive layer.
The work handling sheet according to claim 3, wherein the adhesive constituting the adhesive layer is an active energy ray-curable adhesive.
The work handling sheet according to claim 3 or 4, wherein the adhesive constituting the adhesive layer is an acrylic adhesive.
The work handling sheet according to any one of claims 1 to 5, wherein the laser light has a wavelength in the ultraviolet region.
The work handling sheet according to any one of claims 1 to 6, characterized in that when interfacial ablation is caused in the interfacial ablation layer, blisters are formed at positions where the interfacial ablation occurs.
Any of a plurality of work pieces held on the surface of the interface ablation layer opposite to the base material is removed from the interface ablation layer by the interface ablation locally generated in the interface ablation layer. The work handling sheet according to any one of claims 1 to 7, which is used for selectively separating from.
9. The work piece according to claim 8, wherein the work pieces are obtained by singulating a work held on a surface of the interfacial ablation layer opposite to the base material, on the surface of the work piece. Described work handling sheet.
The work handling sheet according to claim 8 or 9, wherein the small work piece is at least one selected from semiconductor parts and semiconductor devices.
The work handling sheet according to any one of claims 8 to 10, wherein the work pieces are light emitting diodes selected from mini light emitting diodes and micro light emitting diodes.
A work handling sheet comprising a base material and an interface ablation layer containing a photopolymerization initiator laminated on one side of the base material, and having an absorbance of 1.5 or more for light with a wavelength of 355 nm. a preparation step of preparing a laminate in which a plurality of work pieces are held on the layer side surface;
an arrangement step of arranging the laminate so that the surface of the laminate on the side of the small work piece faces an object capable of receiving the small work piece;
By irradiating a laser beam to a position on the interface ablation layer of the laminate to which at least one of the work pieces is attached to cause interface ablation at the irradiated position on the interface ablation layer. and a separating step of separating the small work piece existing at the position where the interface abrasion has occurred from the work handling sheet and placing the small work piece on the object.
12. In the preparation step, the workpiece pieces are obtained by singulating a workpiece held on a surface of the interfacial ablation layer opposite to the base material on the surface of the interface abrasion layer. The device manufacturing method described in .
The device manufacturing method according to claim 12 or 13, wherein the work piece is at least one selected from a semiconductor component and a semiconductor device.
The light-emitting device according to any one of claims 12 to 14, wherein a light-emitting diode selected from mini-light-emitting diodes and micro-light-emitting diodes is used as the work piece to manufacture a light-emitting device comprising a plurality of the light-emitting diodes. Device manufacturing method.
The device manufacturing method according to claim 15, wherein the light emitting device is a display.