KR20230161411A - Work handling sheets and device manufacturing methods - Google Patents

Abstract

A work handling sheet (1) comprising a base material (11) and an interfacial ablation layer (12) laminated on one side of the base material (11), capable of holding small work pieces and performing interfacial ablation by irradiation of laser light. ), the interfacial ablation layer 12 contains a photopolymerization initiator, and the work handling sheet 1 has an absorbance of 1.5 or more for light with a wavelength of 355 nm. This work handling sheet can handle even small, fine work pieces satisfactorily.

Description

Work handling sheets and device manufacturing methods

The present invention relates to a work handling sheet that can be used to handle small work pieces such as semiconductor components or semiconductor devices, and a device manufacturing method using the work handling sheet, and in particular to micro light emitting diodes, power devices, and MEMS (Micro Electro Mechanical Devices). It relates to a work handling sheet that can be used to handle small work pieces such as systems, and a device manufacturing method using the work handling sheet.

In recent years, the development of displays using micro light emitting diodes is in progress. In the display, each pixel is composed of micro light-emitting diodes, and the light emission of each micro light-emitting diode is independently controlled. In manufacturing the display, it is generally necessary to mount micro light emitting diodes arranged on a supply substrate such as sapphire or glass on a wiring board provided with wiring.

During the above mounting, it is necessary to accurately place the plurality of micro light emitting diodes arranged on the supply board at a predetermined position on the wiring board. At this time, it is necessary to selectively mount a predetermined number of the plurality of micro light emitting diodes on the wiring board, or it is necessary to mount the plurality of micro light emitting diodes simultaneously.

From the viewpoint of performing such mounting satisfactorily, the use of laser light irradiation is being considered. For example, after holding a plurality of micro light emitting diodes on a support with a predetermined layer interposed therebetween, laser light is irradiated to the layer to cause ablation of the layer at the irradiated position, thereby causing the layer to be separated from the support. A method of placing (laser lift-off) micro light emitting diodes on a wiring board is being studied (patent document 1). Since the laser light has excellent directivity and convergence, it is easy to control the irradiation position, and selective placement can be performed satisfactorily.

Japanese Patent No. 6546278

However, further miniaturization of micro light-emitting diodes and higher-density packaging of micro light-emitting diodes are also progressing, and in response to these, fine work pieces such as a large number of micro light-emitting diodes are more efficient than conventional methods such as Patent Document 1. A means to deal with is required.

The present invention has been made in view of these actual conditions, and its purpose is to provide a work handling sheet that can favorably handle even fine small work pieces, and a device manufacturing method using the work handling sheet.

In order to achieve the above object, firstly, the present invention provides an interfacial ablation method in which a substrate is laminated on one side of the substrate, capable of holding small work pieces, and performing interface ablation by irradiation of laser light. Provided is a work handling sheet having a layer, 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 One).

In the work handling sheet according to the invention (invention 1), the interface ablation layer contains a photopolymerization initiator and the absorbance of light with a wavelength of 355 nm is within the above range, so that the work handling sheet effectively ablates the interface when irradiated with laser light. , thereby allowing the small work pieces to be separated favorably toward the object.

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 interfacial ablation 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), it is preferable that the laser light has a wavelength in the ultraviolet range (invention 6).

In the above inventions (inventions 1 to 6), when interfacial ablation occurs in the interfacial ablation layer, it is preferable that a blister is formed at the position where the interfacial ablation occurs (invention 7).

In the above inventions (inventions 1 to 7), a plurality of work pieces are held on a surface opposite to the substrate in the interface ablation layer by interfacial ablation locally generated in the interface ablation layer. It is preferable that it is used to selectively separate any work pieces from the interface ablation layer (invention 8).

In the above invention (invention 8), it is preferable that the work pieces are obtained by dividing the work held on the surface opposite to the substrate in the interface ablation layer into pieces on this surface (invention 9).

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

In the above inventions (inventions 8 to 10), the work piece is preferably a light emitting diode selected from mini light emitting diodes and micro light emitting diodes (invention 11).

Second, the present invention is a work handling sheet comprising a substrate and an interfacial ablation layer containing a photopolymerization initiator laminated on one side of the substrate, and having an absorbance of 1.5 or more for light with a wavelength of 355 nm, wherein the interface A preparation step of preparing a laminate in which a plurality of work pieces are held on a surface on the ablation layer side, and, for an object capable of holding the work pieces, the surfaces of the laminate on the work piece side face each other. A placement step of arranging the laminate, irradiating laser light to a position in the interface ablation layer of the laminate where at least one work piece is attached, By generating an interface ablation at the irradiated position, the work piece existing at the position where the interface ablation occurred is separated from the work handling sheet, and a separation process of placing the work piece on the object is provided. A characterized device manufacturing method is provided (invention 12).

In the above invention (invention 12), in the preparation step, it is preferable to obtain the work pieces by dividing the work held on the surface opposite to the substrate in the interface ablation layer into pieces on this surface ( Invention 13).

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

In the above inventions (inventions 12 to 14), it is preferable to use light emitting diodes selected from mini light emitting diodes and micro light emitting diodes as the work pieces to manufacture a light emitting device having a plurality of the light emitting diodes (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 favorably handle even small pieces of fine work, 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.
Figure 2 is a cross-sectional view illustrating a device manufacturing method using a work handling sheet according to an embodiment of the present invention.
Figure 3 is a cross-sectional view explaining the state of blisters and reaction areas generated by irradiation of laser light.

Hereinafter, embodiments of the present invention will be described.

1 shows a cross-sectional view of a work handling sheet according to one embodiment. The work handling sheet 1 shown in FIG. 1 includes a base material 12 and an interface ablation layer 11 laminated on one side of the base material 12.

In the work handling sheet 1 according to this embodiment, the interface ablation layer 11 is capable of holding small work pieces. That is, the work handling sheet 1 according to the present embodiment can maintain the work pieces laminated on the surface of the interface ablation layer 11 opposite to the substrate 12 in that state.

Although the specific mode of the above holding is not limited, a preferred example is holding the interfacial ablation layer 11 by exerting adhesion to the work piece. In this case, as will be described later, the interfacial ablation layer 11 preferably contains an adhesive as one of its constituent components, that is, is an adhesive layer.

Additionally, the interface ablation layer 11 in this embodiment is subjected to interface ablation by irradiation of laser light. That is, the interface ablation layer 11 performs local interface ablation in the area irradiated with the laser light. Moreover, the laser light is not particularly limited as long as it is capable of generating interface ablation, and may be any laser light having a wavelength in the ultraviolet range, visible light range, and infrared range. Among these, laser light having a wavelength in the ultraviolet range may be used. This is desirable.

In this specification, interfacial ablation refers to evaporation or volatilization of a portion of the components constituting the interface ablation layer 11 by the energy of the laser light, and the resulting gas is generated between the interface ablation layer 11 and the substrate 12. ) refers to the formation of voids (blisters) at the interface. In this case, the shape of the interface ablation layer 11 changes due to blisters, and the small work pieces peel off from the interface ablation layer 11, causing the small work pieces to separate.

In addition, the interface ablation layer 11 in this embodiment contains a photopolymerization initiator, and the work handling sheet 1 according to this embodiment has an absorbance of light with a wavelength of 355 nm of 1.5 or more. In this way, the photopolymerization initiator is present in the interfacial ablation layer 11, and the work handling sheet 1 exhibits the above-mentioned absorbance, thereby increasing the efficiency of the interfacial ablation layer 11 in receiving energy from the laser light. It improves. As a result, interfacial ablation occurs effectively, and it becomes possible to properly separate the retained work pieces from the interfacial ablation layer 11. In particular, the amount of laser light irradiation required to produce sufficient separation of work pieces is reduced, thereby reducing the operating cost of the laser light irradiation device, and making it easier to separate only the targeted work pieces well, improving precision. Moreover, damage to devices, etc. due to excessive laser light 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, particularly preferably 2.5 or more, and even more preferably 3.0 or more. Additionally, the upper limit of the absorbance is not particularly limited, and may be, for example, 6.0 or less. In addition, details of the method for measuring the absorbance are as described in the test examples described later.

1. Interfacial ablation layer

The specific structure and composition of the interface ablation layer 11 in the present embodiment is capable of holding small work pieces, has the property of performing interface ablation by irradiation of laser light, and contains a photopolymerization initiator. There is no particular limitation as long as it enables the above-described light absorbency as the work handling sheet 1.

From the viewpoint of easily exhibiting the property of being able to maintain small work pieces, it is preferable that the interfacial ablation layer 11 contains an adhesive as one of the components constituting it, as described above. When the interfacial ablation layer 11 contains an adhesive, the interfacial ablation layer 11 is preferably made of an adhesive composition containing a photopolymerization initiator.

(1) Photopolymerization initiator

The type of photopolymerization initiator in this embodiment is not particularly limited. Examples of preferred photopolymerization initiators 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-morpholinopropane It is preferable to use at least one type of -1-one.

In addition to the photopolymerization initiator, other photopolymerization initiators may be used in combination. Examples of photopolymerization initiators that can be used in combination 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-Hydroxycyclohexylphenylketone, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, 1-[4-(2-hydroxyethoxy)-phenyl]- 2-Hydroxy-methylpropanone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butyl Anthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenone Dimethyl ketal, p-dimethylaminobenzoic acid ester, oligo[2-hydroxy-2-methyl-1[4-(1-methylvinyl)phenyl]propanone], 2,4,6-trimethylbenzoyl-diphenyl-phos Pin oxide, etc. can be mentioned.

The photopolymerization initiator in this embodiment preferably has an absorption peak in a wavelength range of 200 nm or more and 400 nm or less. Accordingly, the interfacial ablation layer 11 efficiently absorbs the laser light, thereby making it easy to perform good interfacial ablation. From this viewpoint, the lower limit of the above range is particularly preferably 300 nm or more, and more preferably 330 nm or more. In addition, the upper limit of the above range is particularly preferably 380 nm or less, and more preferably 370 nm or less.

Additionally, the absorption peak can be specified based on the following method. First, the photopolymerization initiator is dissolved in methanol or acetonitrile as a solvent, and a measurement solution with a concentration of 0.01% by mass is prepared. Subsequently, the absorbance of the measurement solution is measured using a spectrophotometer (for example, “UV-3600” manufactured by Shimadzu Corporation), and an absorption spectrum is obtained. And, from the obtained absorption spectrum, the wavelength range of the absorption peak (nm) can be specified.

In addition, the photopolymerization initiator in this embodiment preferably has an absorbance at a wavelength of 355 nm in a solution with a concentration of 0.01 mass% of 0.5 or more, particularly preferably 0.75 or more, and more preferably 1.0 or more. When the absorbance is 0.5 or more, the interfacial ablation layer 11 efficiently absorbs the laser light, thereby facilitating interfacial ablation. Additionally, the upper limit of the absorbance is not particularly limited, and may be, for example, 4.0 or less.

In addition, the absorbance is determined by preparing a methanol solution with a concentration of 0.01% by mass of the photopolymerization initiator (if the photopolymerization initiator is insoluble in methanol, an acetonitrile solution) and measuring the wavelength in the range of 200 to 500 nm in the solution. The absorbance 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 this embodiment is preferably 1.8% by mass or more, particularly preferably 3.0% by mass or more, and more preferably 5.0% by mass or more. When the content of the photopolymerization initiator is 1.8% by mass or more, the interfacial ablation layer 11 absorbs the laser light efficiently, thereby making it easy to perform interfacial ablation favorably. Furthermore, the content of the photopolymerization initiator in the interface ablation layer 11 in this embodiment is preferably 40.0% by mass or less, particularly preferably 30.0% by mass or less, and more preferably 25.0% 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 interface ablation layer 11 becomes appropriate, and it becomes easy to ensure good film forming properties.

In addition, when the interface ablation layer 11 in this embodiment is formed from the adhesive composition described later, a photopolymerization initiator may be blended in this adhesive composition. In particular, when the photopolymerization initiator is blended into 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 based on 100 parts by mass of the active energy ray-curable polymer (A) described later. , it is preferably 1.8 parts by mass or more, especially preferably 3.0 parts by mass or more, and even more preferably 5.0 parts by mass or more. When the amount of the photopolymerization initiator is 1.8 parts by mass or more, the interfacial ablation layer 11 absorbs the laser light efficiently, thereby making it easy to perform good interfacial ablation. In addition, the amount of the photopolymerization initiator in the adhesive composition is preferably 40.0 parts by mass or less, especially 30.0 parts by mass or less, and more preferably 25.0 parts by mass or less, based on 100 parts by mass of the active energy ray-curable polymer (A). It is desirable. When the amount of the photopolymerization initiator is 40.0 parts by mass or less, the resulting adhesive easily exhibits the desired adhesive strength.

(2) Adhesive

As described above, the interfacial ablation layer 11 in this embodiment may contain an adhesive in addition to the photopolymerization initiator. In this case, the interfacial ablation layer 11 is preferably formed of an adhesive composition containing a photopolymerization initiator.

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

In addition, the adhesive may be an adhesive that does not have active energy ray curing properties, but is preferably an adhesive that has active energy ray curing properties (hereinafter sometimes referred to as “active energy ray curable adhesive”). When the interfacial ablation layer 11 is composed of an active energy ray-curable adhesive, the interfacial ablation layer 11 is hardened by irradiation of active energy rays to facilitate the adhesion of the work handling sheet 1 to the adherend. It can be seriously degraded.

In particular, by combining the reduction of adhesion by irradiation of active energy rays with the above-described interface ablation, separation of small work pieces from the work handling sheet 1 becomes easy. That is, separation of small work pieces from the work handling sheet 1 according to the present embodiment is achieved by reducing adhesion by irradiation of active energy rays before generating the above-mentioned interface ablation or simultaneously with the above-mentioned interface ablation. It becomes possible to act more reliably. Additionally, it becomes possible to further reduce the amount of laser light required to cause sufficient separation of work pieces.

The active energy ray curable adhesive may be one containing a polymer having active energy ray curing properties as a main component, and may have an active energy ray non-curing polymer (polymer without active energy ray curing property) and at least one active energy ray curing group. It may be one whose main component is a mixture of monomers and/or oligomers. Additionally, the active energy ray-curable adhesive may be a mixture of a polymer having active energy ray-curable properties and a monomer and/or oligomer having at least one active energy ray-curable group.

The polymer having active energy ray curability is a (meth)acrylic acid ester (co)polymer (A) (hereinafter referred to as “active energy ray curable polymer (A)” into which a functional group (active energy ray curable group) having energy ray curability is introduced into the side chain. )”, it is preferable. This active energy ray-curable polymer (A) is preferably obtained by reacting an acrylic copolymer (a1) having a functional group-containing monomer unit with an unsaturated group-containing compound (a2) having a functional group bonded to the functional group. In addition, in this specification, (meth)acrylic acid ester means both acrylic acid ester and methacrylic acid ester. The same goes for other similar terms. In addition, “polymer” shall also include the concept of “copolymer.”

The acrylic copolymer (a1) preferably contains a structural unit derived from a functional group-containing monomer and a structural unit derived from a (meth)acrylic acid ester monomer or a derivative thereof.

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

Examples of hydroxy group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate. Acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc. are mentioned, and these are used individually or in combination of two or more types.

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

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

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

As alkyl (meth)acrylate, especially alkyl (meth)acrylate whose alkyl group has 1 to 18 carbon atoms, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n -Butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, etc. are preferably used. These may be used individually or in combination of two or more types.

Examples of monomers containing an alicyclic structure include cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, adamantyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentenyl (meth)acrylate. , dicyclopentenyloxyethyl (meth)acrylate, etc. are preferably used. These may be used individually or in combination of two or more types.

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

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

The acrylic copolymer (a1) is obtained by copolymerizing the above-mentioned functional group-containing monomer and a (meth)acrylic acid ester monomer or a derivative thereof by a conventional method. In addition to these monomers, dimethylacrylamide, vinyl formate, vinyl acetate, Styrene and the like may be copolymerized.

An active energy ray-curable polymer (A) is obtained by reacting the acrylic copolymer (a1) having the functional group-containing monomer unit with an unsaturated group-containing compound (a2) 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 hydroxy group, amino group, or substituted amino group, the functional group of the unsaturated group-containing compound (a2) is preferably an isocyanate group or an epoxy group, and the functional group of the acrylic copolymer (a1) is preferably an isocyanate group or an epoxy group. When the functional group is an epoxy group, the functional group of the unsaturated group-containing compound (a2) is preferably an amino group, a carboxyl group, or an aziridinyl group.

In addition, the unsaturated group-containing compound (a2) contains at least one, preferably 1 to 6, more preferably 1 to 4 energy ray polymerizable carbon-carbon double bonds per molecule. Specific examples of such unsaturated group-containing compound (a2) include, for example, 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1 ,1-(bisacryloyloxymethyl)ethyl isocyanate; An acryloyl monoisocyanate compound obtained by reaction of a diisocyanate compound or polyisocyanate compound and hydroxyethyl (meth)acrylate; An acryloyl monoisocyanate compound obtained by reaction of a diisocyanate compound or 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 50 mol% or more, particularly preferably 60 mol% or more, and more preferably 70 mol% or more relative to the mole number of functional group-containing monomers of the acrylic copolymer (a1). It is used as a ratio. In addition, the unsaturated group-containing compound (a2) is preferably 95 mol% or less, particularly preferably 93 mol% or less, and more preferably 90 mol%, relative to the mole number of functional group-containing monomers of the acrylic copolymer (a1). It is used at a ratio of % or less.

In the reaction between the acrylic copolymer (a1) and the unsaturated group-containing compound (a2), the temperature of the reaction depends on the combination of the functional group of the acrylic copolymer (a1) with the functional group of the unsaturated group-containing compound (a2), Pressure, solvent, time, presence or absence of catalyst, and type of catalyst can be appropriately selected. Accordingly, the functional group present in the acrylic copolymer (a1) reacts with the functional group in the unsaturated group-containing compound (a2), and the unsaturated group is introduced into the side chain of the acrylic copolymer (a1), forming an active energy ray-curable polymer (A). is obtained.

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, and more preferably 100,000 or more. Furthermore, the weight average molecular weight (Mw) is preferably 3 million or less, especially 2 million or less, and more preferably 1.5 million or less. In addition, the weight average molecular weight (Mw) in this specification is a standard polystyrene conversion value measured by gel permeation chromatography (GPC method).

Even if the active energy ray-curable adhesive is mainly composed of a polymer having active energy ray-curable properties such as the active energy ray-curable polymer (A), the active energy ray-curable adhesive is composed of an energy ray-curable monomer and/or oligomer (B). It may contain more.

As the active energy ray-curable monomer and/or oligomer (B), for example, ester of a 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, and trimethylolpropane tri(meth)acrylate. ) Acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6 -Multifunctional acrylic acid esters such as hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, dimethylol tricyclodecane di(meth)acrylate, polyester oligo(meth)acrylate, polyurethane oligo (meth)acrylate, etc. can be mentioned.

When mixing an 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 oligomer (B) in the active energy ray curable adhesive The content is preferably more than 0 parts by mass, and is especially preferably 60 parts by mass or more, based on 100 parts by mass of the active energy ray-curable polymer (A). Furthermore, the content is preferably 250 parts by mass or less, and especially preferably 200 parts by mass or less, based on 100 parts by mass of the active energy ray-curable polymer (A).

Next, the case where the active energy ray-curable adhesive mainly contains 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 will be described below.

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

As the monomer and/or oligomer having at least one active energy ray-curable group, the same ones as the component (B) described above can be selected. The mixing 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 one active energy ray curable group per 100 parts by mass of the active energy ray non-curable polymer component. It is preferable that the monomer and/or oligomer it has is 1 part by mass or more, and it is especially preferable that it is 60 parts by mass or more. In addition, the mixing ratio is preferably 200 parts by mass or less of the monomer and/or oligomer having at least one active energy ray-curable group, based on 100 parts by mass of the active energy ray non-curable polymer component, and is particularly preferably 160 parts by mass or less. .

(3) Other ingredients

Other components may be appropriately added to the adhesive composition described above. Other components include, for example, an active energy ray non-curable polymer component or oligomer component (D), a crosslinking agent (E), etc.

Examples of the active energy ray non-curable polymer component or oligomer component (D) include polyacrylic acid ester, polyester, polyurethane, polycarbonate, polyolefin, etc., and have a weight average molecular weight (Mw) of 30 million to 2.5 million. Polymers or oligomers are preferred. By mixing the component (D) into an energy-ray curable adhesive, the adhesiveness and peelability before curing, the strength after curing, adhesion to other layers, storage stability, etc. can be improved. The mixing 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 a crosslinking agent (E) is preferable from the viewpoint that it is easy to adjust the storage elastic modulus of the interfacial ablation layer 11 to a desired range. As the crosslinking agent (E), a polyfunctional compound that has reactivity with the functional group of the active energy ray-curable copolymer (A) or the like can be used. Examples of such multifunctional 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 resins, etc. can be mentioned.

The compounding amount of the crosslinking agent (E) is preferably 0.001 parts by mass or more, especially 0.1 parts by mass or more, and more preferably 0.2 parts by mass or more, based on 100 parts by mass of the active energy ray-curable copolymer (A). Moreover, the compounding amount of the crosslinking agent (E) is preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, with respect to 100 parts by mass of the active energy ray-curable copolymer (A). do.

Additionally, other components that can be mixed in the adhesive composition include additives such as tackifiers, coloring materials such as dyes and pigments, flame retardants, fillers, and antistatic agents. In addition, the adhesive composition preferably does not contain a gas generating agent from the viewpoint of easily causing separation of work pieces. When a gas generating agent is used, gas may be generated throughout the interface ablation layer 11. In that case, there are cases where interface ablation occurs only at the intended location, making it difficult to separate only the small work pieces located there, making it difficult to separate the small work pieces satisfactorily.

(4) Thickness of interfacial ablation layer

The thickness of the interface ablation layer 11 in this embodiment is preferably 3 μm or more, particularly preferably 20 μm or more, and more preferably 25 μm or more. Additionally, the thickness of the interface ablation layer 11 is preferably 100 μm or less, especially 50 μm or less, and more preferably 40 μm or less. When the thickness of the interface ablation layer 11 is within the above range, it is easy to achieve both maintenance of the small work pieces on the interface ablation layer 11 and separation of the work pieces by the interface ablation.

2. Description

The base material 12 in this embodiment is not particularly limited in terms of its composition or physical properties. From the viewpoint that the work handling sheet 1 can easily exhibit the desired function, the base material 12 is preferably made of resin. When the base material 12 is made of 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-based copolymer resins such as ethylene-(meth)acrylic acid copolymer, ethylene-methyl (meth)acrylate copolymer, and other ethylene-(meth)acrylic acid ester copolymers; Polyvinyl chloride-based resins such as polyvinyl chloride and vinyl chloride copolymer; (meth)acrylic acid ester copolymer; Polyurethane; polyimide; polystyrene; polycarbonate; Fluororesin, etc. can be mentioned. In addition, the resin constituting the base material 12 may be a crosslinked product of the above-mentioned resin or a modified product such as an ionomer of the above-mentioned resin. In addition, the base material 12 may be a single-layer film made of the above-mentioned resin, or may be a laminated film in which a plurality of the above films are laminated. In this laminated film, the materials constituting each layer may be of the same type or may be of different types.

The surface of the substrate 12 in this embodiment may be subjected to surface treatment using an oxidation method, 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 process), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment, and examples of the roughening method include sand blasting. Examples include methods of spraying and spraying.

The base material 12 in this embodiment may contain various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, and fillers. Additionally, 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, melt extrusion methods such as the T die method and the ring die method; calendar method; It can be manufactured by molding the resin into a sheet shape using 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, and more preferably 50 μm or more. Additionally, the thickness of the substrate 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 most preferably 100 μm or less. When the thickness of the base material 12 is within the above range, the work handling sheet 1 has a predetermined balance of rigidity and flexibility, making it easy to handle small work pieces well.

3. Release sheet

In the present embodiment, when the interfacial ablation layer 11 contains an adhesive as one of its constituent components, the surface of the interfacial ablation layer 11 opposite to the substrate 12 is attached to a small work piece. For the purpose of protecting the surface during this period, a release sheet may be laminated on the surface.

The configuration of the release sheet is arbitrary, and an example is one in which a plastic film has been subjected to 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, silicone-based, fluorine-based, long-chain alkyl-based, etc. can be used, and among these, silicone-based is preferable because it is inexpensive and provides stable performance.

There is no particular limitation on the thickness of the release sheet, and for example, it may be 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 ablation layer 11 opposite to the substrate 12. In the above sheet, a work is attached to the side of the adhesive layer opposite to the interface ablation layer 11, and the adhesive layer is diced together with the work to obtain small work pieces in which the separated adhesive layers are laminated. You can. The chip can be easily fixed to the object on which the work piece is mounted by this separate adhesive layer. As the material constituting the above-mentioned adhesive layer, it is preferable to use a material containing a thermoplastic resin and a low molecular weight thermosetting adhesive component, or a material containing a B stage (semi-cured burn) thermosetting adhesive component.

Additionally, 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 ablation 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 interface ablation layer 11, and the protective film forming layer is diced together with the work to obtain small work pieces in which the separate protective film forming layers are laminated. You can. As the work, it is preferable to use one on which a circuit is formed on one side, and 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 separated protective film forming layer at a predetermined timing, a protective film with sufficient durability can be formed on a small piece of work. The protective film forming layer is preferably made of an uncured curable adhesive.

5. Physical properties of work handling sheets

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, especially 100 mN/25 mm or more, and more preferably 200 mN/25 mm or more. desirable. When the adhesive force is 10 mN/25 mm or more, it becomes easy to secure adherends such as small work pieces to the work handling sheet 1, resulting in more excellent handling properties. Additionally, the adhesive force is preferably 30,000 mN/25 mm or less, especially 15,000 mN/25 mm or less, and more preferably 10,000 mN/25 mm or less. When the adhesive force is 30000 mN/25 mm or less, it becomes easier to separate work pieces by irradiating laser light more effectively.

In addition, when the interfacial ablation layer 11 in this embodiment is a pressure-sensitive adhesive layer composed of the above-mentioned active energy ray-curable pressure-sensitive adhesive, it is preferable to satisfy the following conditions regarding the adhesive strength after ultraviolet irradiation. That is, the surface of the interface ablation layer 11 opposite to the substrate 12 is attached to the mirror surface of a silicon wafer, and ultraviolet rays are irradiated to the interface ablation layer 11 using a high-pressure mercury lamp to form an interface. The adhesion to the mirror surface of the silicon wafer after curing the ablation layer 11 is preferably 2000 mN/25 mm or less, particularly preferably 1000 mN/25 mm or less, and more preferably 200 mN/25 mm or less. . When the adhesive force is 2000 mN/25 mm or less, it becomes easy to separate the work pieces well by subsequent interface ablation. In addition, the lower limit of the adhesive strength is not particularly limited, and may be, for example, 5 mN/25 mm or more, especially 10 mN/25 mm or more, and furthermore, 20 mN/25 mm or more.

In addition, the details of the method for measuring these adhesive forces are as described in the test examples described later.

6. Manufacturing method of work handling sheet

The manufacturing method of the work handling sheet 1 according to this embodiment is not particularly limited. For example, the interfacial ablation layer 11 may be formed directly on the substrate 12, or the interfacial ablation layer 11 may be formed on a process sheet and then the interfacial ablation layer 11 may be applied to the substrate. (12) It may be transferred onto the image.

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, an adhesive composition for forming the interfacial ablation layer 11 and a coating liquid further containing a solvent or dispersion medium as desired are prepared. Then, the above-mentioned coating liquid is applied to one side of the substrate or the releasable side of the release sheet (hereinafter sometimes referred to as “release surface”). Subsequently, the interfacial ablation layer 11 can be formed by drying the obtained coating film.

Application of the above-mentioned coating liquid can be performed by a known method, for example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, or a gravure coating method. In addition, the properties of the coating liquid are not particularly limited as long as it can be applied. In some cases, it contains a component for forming the interface ablation layer 11 as a solute or as a dispersoid. There is also. In addition, when the interfacial ablation layer 11 is formed on the release sheet, the release sheet may be peeled off as a process material, and may protect the interface ablation layer 11 until it is attached to the adherend. good night.

When the adhesive composition for forming the interfacial ablation layer 11 contains the above-mentioned crosslinking agent, the polymer component in the coating film is removed by changing the drying conditions (temperature, time, etc.) described above or by separately providing heat treatment. It is preferable to proceed with the crosslinking reaction between the crosslinking agent and the crosslinking agent to form a crosslinked structure at a desired density within the interfacial ablation layer 11. In addition, in order to sufficiently advance the above-mentioned crosslinking reaction, after completion of the work handling sheet 1, curing may be performed, for example, by leaving it to stand in an environment of 23° C. and 50% relative humidity for several days.

7. How to use the work handling sheet

The work handling sheet 1 according to this embodiment can be suitably used for handling small work pieces. As described above, in the work handling sheet 1 according to the present embodiment, the interface ablation layer 11 is one that efficiently performs interface ablation by irradiation of laser light, so that the interface ablation layer 11 is The held work pieces can be separated toward a predetermined position with high precision.

As an example of a method of using the work handling sheet 1 according to the present embodiment, the substrate 12 in the interface ablation layer 11 is removed by interfacial ablation locally generated in the interface ablation layer 11. One possible use method is to selectively separate any work piece from the plurality of work pieces held on the opposite side from the interface ablation layer 11.

In the above usage method, the plurality of work pieces held on the interface ablation layer 11 are works held on the surface opposite to the substrate 12 in the interface ablation layer 11 (material of the work pieces). It may be obtained by reorganizing) into pieces on the above-mentioned surface. That is, the work pieces may be obtained by dicing the work on the interface ablation layer 11. Alternatively, the work piece may be formed independently from the work handling sheet 1 according to the present embodiment and placed on the interface ablation layer 11.

Additionally, when the work handling sheet 1 according to the present embodiment is provided with the adhesive layer or protective film forming layer described above, it is preferable to dice these layers and the work on the interface ablation layer 11. Accordingly, it is possible to obtain small workpieces in which these layers are separated and laminated.

There is no particular limitation on the shape or size of the small work piece in this embodiment, but with regard to size, the small work piece preferably has an area of 10 ㎛ ² or more when viewed in plan view, and especially 100 ㎛ ² or more. It is desirable. Additionally, the area of the small work piece when viewed in plan view is preferably 1 mm2 or less, and especially preferably 0.25 mm2 or less. Additionally, as for the size of the work piece, when the work piece is rectangular, the smallest side of the work piece is preferably 2 μm or more, particularly preferably 5 μm or more, and more preferably 10 μm or more. In addition, the minimum one side is preferably 1 mm or less, and particularly preferably 0.5 mm or less. Specific examples of the dimensions of the small rectangular work pieces include 2 μm × 5 μm, 10 μm × 10 μm, 0.5 mm × 0.5 mm, and 1 mm × 1 mm. The work handling sheet 1 according to the present embodiment can favorably handle such fine work pieces, especially fine work pieces that are difficult to separate from the sheet by pushing up the needle. On the other hand, the work handling sheet 1 according to the present embodiment has an area exceeding 1 mm2 (for example, 1 mm2 to 2000 mm2) or a thickness of 1 to 10000 μm (for example, 10000 μm). Even small workpieces of relatively large sizes (~1000㎛) can be handled well.

Small work pieces include semiconductor components and semiconductor devices, and more specifically, micro light emitting diodes, power devices, and MEMS (Micro Electro Mechanical Systems). Among these, the work piece is preferably a light emitting diode, and is particularly preferably a light emitting diode 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 arranged at high density have been studied, and in the manufacture of such devices, a work handling sheet (1) according to this embodiment that can handle these light-emitting diodes with high precision is used. ) is very suitable.

Below, as a specific example of use of the work handling sheet 1, a device manufacturing method will be explained based on FIG. 2. The device manufacturing method includes at least three processes: a preparation process ((a) in Figure 2), a batch process ((b) in Figure 2), and a separation process ((c) and (d) in Figure 2). do.

In the preparation process, as shown in Figure 2 (a), a plurality of 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. Prepare a laminate consisting of The laminate may be prepared by placing separately manufactured work pieces 2 on the work handling sheet 1, or the work held on the surface on the interface ablation layer 11 side may be reorganized on this surface. You can prepare it by mashing it (i.e. dicing it). The dicing can be performed by a known method.

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

In the subsequent arrangement process, as shown in (b) of FIG. 2, the work pieces 2 are stacked so that the surfaces of the work pieces 2 in the laminate face each other with respect to the object 3 that can accommodate the work pieces 2. Place the sieve. Examples of the object 3 are appropriately determined depending on the device to be manufactured, but when the work piece 2 is a light emitting diode, specific examples of the object 3 include a board, sheet, reel, etc., especially wiring. This provided wiring board is preferably used.

Thereafter, in the separation process, as shown in FIG. 2(c), the position where at least one work piece 2 is attached in the interfacial ablation layer 11 of the laminate is as follows: Irradiate laser light. The above irradiation may be performed simultaneously on a plurality of positions where the work piece 2 is attached, or may be performed sequentially on these positions. Conditions for irradiation of the laser light are not limited as long as it is possible to generate interfacial ablation. As a device for irradiation, a known device can be used.

By the above irradiation, as shown in FIG. 2(d), interface ablation can be generated at the irradiated position in the interface ablation layer 11. Specifically, by irradiation of the laser light, the components constituting the region are evaporated or volatilized in the region proximal to the substrate 12 in the interface ablation layer 11, forming a reaction region 13. ) becomes. Then, the gas generated by the evaporation or volatilization collects between the substrate 11 and the reaction region 13, forming a blister 5. By forming the blister 5, the interface ablation layer 11 is locally deformed at the position of the work piece 2', and the work piece 2' is peeled off from the interface ablation layer 11. This is separated. As a result of the above, the work piece 2' existing at the position where the interface ablation occurred can be placed on the object 3.

Additionally, the reaction area 13 and blisters 5 generated by irradiation of the laser light usually remain even after the work piece 2' is separated. Figure 3 shows the separation of work pieces 2 by sequential irradiation of laser light, in particular the state after separation (two on the left), the state during separation (center), and the state before separation (two on the right). dog) appears. As shown, the blister 5 after separation is usually in a slightly collapsed state compared to the blister 5 during separation.

In addition, when the interface ablation layer 11 in the present embodiment is an adhesive layer composed of the above-described active energy ray-curable adhesive, the above-described device manufacturing method may further include the following curing process. That is, for the entire interface ablation layer 11 in a laminate formed by holding a plurality of work pieces 2 on the surface on the interface ablation layer 11 side, or for the interface ablation layer in the laminate. A curing process is provided to cure the interfacial ablation layer 11 overall or locally by irradiating active energy rays to the position in the ablation layer 11 where at least one work piece 2 is attached. It's okay to do it. This curing process may be performed before the separation process described above, or may be performed simultaneously with the separation process described above.

As described above, by curing the interfacial ablation layer 11 overall or locally by irradiation of active energy rays, the adhesion of the work handling sheet 1 to the work piece 2 can be reduced, When interfacial ablation occurs, it becomes easy to separate the work pieces 2 in a good manner. Irradiation of active energy rays in the curing process may be performed using a known method, for example, an ultraviolet irradiation device equipped with a high-pressure mercury lamp or ultraviolet LED as a light source, or a laser light irradiation device also used in the separation process. You may use it. When performing the curing process and the separation process simultaneously, it is preferable to perform irradiation of the laser light 4 using a laser beam irradiation device as a combination of irradiation of active energy rays.

The device manufacturing method described above may include processes other than a preparation process, a batch process, a curing process, and a separation process. For example, grinding, die bonding, wire bonding, molding, inspection, transfer processes, 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 or 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 having a plurality of such light emitting diodes can be manufactured, and more specifically, a display can be manufactured. can do. In particular, a display including micro light-emitting diodes as pixels or a display including a plurality of mini light-emitting diodes as backlights can be manufactured.

Additionally, the work handling sheet 1 according to the present embodiment can also be used for a method of selectively removing a given work piece 2 from among a plurality of work pieces 2 provided on the sheet.

For example, after manufacturing a plurality of light emitting diodes, etc. on the work handling sheet 1 according to this embodiment, the light emitting diodes are inspected on the sheet. Only the light emitting diodes confirmed to be defective products can be removed by causing interface ablation to cause them to detach from the work handling sheet 1.

Additionally, a collection of these good products can be transferred from the work handling sheet 1 to a shipping sheet. At this time, when the interfacial ablation layer 11 is composed of the above-described active energy ray-curable adhesive, the light emitting diode of the work handling sheet 1 is irradiated with active energy rays to the interfacial ablation layer 11. By reducing the adhesion to the product, a set of good products can be successfully transferred to a shipping sheet. Thereafter, the work handling sheet 1 with only good products can be obtained by rearranging separately manufactured good products in the position from which the defective products were removed.

In the method of removing defective products by interfacial ablation as described above, there is no need to expand the sheet and pick up the defective products, so it is difficult to change the spacing or misalignment of the light emitting diodes. Therefore, it becomes easy to transfer it well to a shipping sheet.

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

For example, between the interfacial ablation layer 11 and the substrate 12 in the work handling sheet 1 according to the present embodiment, or on the side opposite to the interfacial ablation layer 11 of the substrate 12. Other layers may be laminated on the surface. Specific examples of the other layers include an adhesive layer. In this case, the above-mentioned separation process, etc. can be performed with the surface on the adhesive layer side affixed to a support (transparent substrate such as a glass plate).

The adhesive constituting the adhesive layer is not particularly limited, but is preferably one that is difficult to absorb active energy rays and difficult to block active energy rays. In this case, when laser light is irradiated through the adhesive layer, the laser light easily reaches the interface ablation layer 11, making it easy to generate good interface ablation. Specifically, as the adhesive constituting the adhesive layer, it is preferable to use an adhesive that does not have active energy ray curing properties, and it is especially preferable to use an adhesive that does not contain an active energy ray curing component. By using an adhesive that does not have active energy ray curing properties, the adhesive layer does not harden even when irradiated with the laser light, thereby preventing unintentional peeling of the work handling sheet 1 from the transparent substrate. It becomes possible. The thickness of the adhesive layer is not particularly limited, but is preferably 5 to 50 μm, for example.

Example

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

[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 solution polymerization to obtain a (meth)acrylic acid ester polymer. For this (meth)acrylic acid ester polymer, 90 mol% of methacryloyloxyethyl isocyanate (MOI) is reacted with 2-hydroxyethyl acrylate to produce (meth)acrylic acid with an active energy ray curable group introduced into the side chain. An ester copolymer (active energy ray-curable polymer (A)) was obtained. The weight average molecular weight (Mw) of this active energy ray-curable polymer (A) was measured by the method described above and was found to be 800,000.

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

(2) Production of work handling sheets

Regarding the easily adhesive treated side of a polyethylene terephthalate film (manufactured by TOYOBO CO., LTD., product name "COSMOSHINE A4100", thickness: 50 ㎛) on which one side has been subjected to an easily adhesive treatment as a substrate, the above process (1) ) was applied, and the obtained coating film was dried by heating. Accordingly, an interfacial ablation layer (adhesive layer) with a thickness of 30 μm was formed on the substrate.

Subsequently, a release sheet (manufactured by LINTEC Corporation, product name "SP-PET381031") in which a silicone-based release agent layer is formed on the side opposite to the substrate in the interfacial ablation layer and on one side of a polyethylene terephthalate film with a thickness of 38 μm. ) were bonded together. Accordingly, a work handling sheet was obtained in which a release sheet, an interface ablation layer, and a base material were laminated in that order.

(3) Method for measuring weight average molecular weight

The above-mentioned weight average molecular weight (Mw) is the weight average molecular weight in terms of standard polystyrene measured (GPC measurement) using gel permeation chromatography (GPC) under the following conditions.

<Measurement conditions>

·Measurement device: manufactured by TOSOH CORPORATION, HLC-8320

·GPC column (passed in the following order): manufactured by TOSOH CORPORATION

TSK gel superH-H

TSK gel superHM-H

TSK gel superH2000

·Measurement solvent: tetrahydrofuran

·Measurement temperature: 40℃

[Examples 2 to 3 and Comparative Examples 1 to 3]

A work handling sheet was manufactured 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. In addition, Comparative Example 1 is an example in which no photopolymerization initiator was used.

[Test Example 1] (Measurement of ultraviolet ray absorbance)

The release sheet was peeled from the work handling sheets manufactured in Examples and Comparative Examples, and the interfacial ablation layer was exposed. For this work handling sheet, ultraviolet rays were measured using an ultraviolet, visible, and near-infrared spectrophotometer (product name “UV-3600” manufactured by Shimadzu Corporation) and an attached large sample chamber (product name “MPC-3100” manufactured by Shimadzu Corporation). Absorbance was measured. The measurement was performed by irradiating light with a wavelength of 355 nm toward the surface on the interface ablation layer side with a slit width of 20 nm using an integrating sphere built into the large sample chamber. The results are shown in Table 1.

[Test Example 2] (Measurement of adhesive force)

The work handling sheets manufactured in the examples and comparative examples were cut into strips with a width of 25 mm. The release sheet is peeled off from the obtained single-shaped work handling sheet, and the exposed surface of the exposed interface ablation layer is mirror-finished, with respect to the mirror surface of the silicon wafer, temperature 23°C, relative humidity. In a 50% environment, it was attached using a 2 kg rubber roller and left to stand for 20 minutes to serve as a sample for measuring adhesive force.

Afterwards, using a universal tensile tester (manufactured by Orientec Inc., 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 The adhesive force (mN/25 mm) to the mirror surface of the silicon wafer was measured using the 180° peeling method according to Z0237:2009. The results are shown in Table 1 as adhesive strength before ultraviolet irradiation.

Additionally, for the interface ablation layer in the sample for adhesion measurement obtained in the same manner as above, an ultraviolet irradiation device (manufactured by LINTEC Corporation, product name "RAD-2000") equipped with a high-pressure mercury lamp as a light source was used through the substrate. Then, ultraviolet rays were irradiated (illuminance: 230 mW/cm2, light quantity: 190 mJ/cm2), and the interfacial ablation layer was cured. For this sample for measuring adhesive force after irradiation with ultraviolet rays, the adhesive force (mN/25 mm) to the mirror surface of the silicon wafer was measured in the same manner as above. The results are shown in Table 1 as adhesive strength after ultraviolet irradiation.

[Test Example 3] (Evaluation of Laser Lift-Off Aptitude)

(1) Preparation of chips on the work handling sheet (preparation process)

The adhesive side of a dicing sheet (manufactured by LINTEC Corporation, product name “D-485H”) was attached to one side of a silicon wafer (#2000, thickness: 350 μm). Subsequently, a ring frame for dicing was attached to the peripheral portion of the adhesive surface of the dicing sheet (a position that does not overlap with the silicon wafer). Additionally, the dicing sheet was cut to match 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 device (manufactured by DISCO CORPORATION, product name “DFD6362”). After that, the dicing sheet was irradiated with ultraviolet rays (illuminance 230 mW/cm2, light quantity 190 mJ/cm2). Accordingly, a laminate in which a plurality of chips were provided on a dicing sheet was obtained.

Subsequently, the release sheet was peeled from the work handling sheet manufactured in the examples and comparative examples, and the exposed surface thus exposed was bonded to the surface of the laminate obtained as above where a plurality of chips were present. After that, the dicing sheet was peeled from the plurality of chips. Accordingly, a plurality of chips were transferred from the dicing sheet to a work handling sheet, and a laminate in which a plurality of chips were provided on the work handling sheet was obtained.

(2) Separation of chips by laser light irradiation (separation process)

The laminate obtained in step (1) above, in which a plurality of chips are provided on a work handling sheet, was irradiated with laser light to the chips through the work handling sheet using a laser light irradiation device.

Specifically, laser light with a wavelength of 355 nm was irradiated to the chip through the work handling sheet using a laser light irradiation device (manufactured by KEYENCE CORPORATION, product name "MD-U1000C"). The above irradiation was performed by sequentially irradiating the laser light spot to the center of the chip as if drawing a circle. At this time, the diameter of the laser beam spot was set to 25 ㎛, and the inner diameter of the ring formed as the irradiation trace was 65 ㎛. Other irradiation conditions were frequency: 40 kHz, scan speed: 500 mm/s, and irradiation amount: 50 μJ/shot. Additionally, the survey was conducted on 100 chips (matching 10 chips vertically and 10 horizontally) from a plurality of chips.

(3) Confirmation of blisters and chip separation

Regarding the work handling sheet and chips that were investigated above, the presence or absence of blisters at the interface between the substrate in the work handling sheet and the interfacial ablation layer was confirmed, and the presence or absence of chips from the work handling sheet was confirmed. Laser lift-off aptitude was evaluated based on the following criteria. The results are shown in Table 1.

◎ … Blisters occurred at the locations of all 100 chips, and all 100 chips were detached.

○ … The number of chips that blistered and fell off was 80 to 100.

×… The number of chips that blistered and fell off was less than 80.

In addition, details such as abbreviations listed in Table 1 are as follows.

IrugacureOXE02: Ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(0-acetyloxime) (manufactured by BASF Corporation, 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”)

[Table 1]

As is clear from Table 1, the work handling sheets manufactured in Examples had excellent laser lift-off aptitude.

The work handling sheet of the present invention can be suitably used in the manufacture of displays including micro light-emitting diodes as pixels.

1: Work handling seat
11: Interfacial ablation layer
12: Description
13: reaction area
2, 2': Work small piece
3: object
4: Laser light
5: Blister
6: Laser light irradiation point

Claims (16)

With equipment,
A work handling sheet that is laminated on one side of the substrate and has an interfacial ablation layer that is capable of holding small work pieces and performs interfacial ablation by irradiation of laser light,
The interfacial ablation layer contains a photopolymerization initiator,
The work handling sheet is characterized in that the absorbance of light with a wavelength of 355 nm is 1.5 or more. According to paragraph 1,
A work handling sheet, characterized in that the photopolymerization initiator has an absorption peak in a wavelength range of 200 nm to 400 nm. According to claim 1 or 2,
A work handling sheet, wherein the interfacial ablation layer is an adhesive layer. According to paragraph 3,
A work handling sheet, characterized in that the adhesive constituting the adhesive layer is an active energy ray-curable adhesive. According to clause 3 or 4,
A work handling sheet, characterized in that the adhesive constituting the adhesive layer is an acrylic adhesive. According to any one of claims 1 to 5,
A work handling sheet, characterized in that the laser light has a wavelength in the ultraviolet range. According to any one of claims 1 to 6,
A work handling sheet, wherein when interfacial ablation occurs in the interfacial ablation layer, a blister is formed at the location where the interfacial ablation occurred. According to any one of claims 1 to 7,
By the interfacial ablation locally generated in the interface ablation layer, any work piece among the plurality of work pieces held on the surface opposite to the substrate in the interface ablation layer is subjected to the interface ablation. A work handling sheet, characterized in that it is used for selective separation from a layer. According to clause 8,
A work handling sheet, characterized in that the work pieces are obtained by dividing a work held on a side opposite to the substrate in the interface ablation layer into pieces on this side. According to clause 8 or 9,
A work handling sheet, characterized in that the work piece is at least one type selected from semiconductor components and semiconductor devices. According to any one of claims 8 to 10,
A work handling sheet, wherein the work piece is a light emitting diode selected from mini light emitting diodes and micro light emitting diodes. A work handling sheet 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, the surface on the side of the interfacial ablation layer A preparation process for preparing a laminate formed by holding a plurality of work pieces on a bed,
A placement step of arranging the laminate so that surfaces on the work piece side of the laminate face each other with respect to an object capable of holding the work piece,
Laser light is irradiated to a position in the interface ablation layer of the laminate where at least one work piece is attached, and interfacial ablation is generated at the irradiated position in the interface ablation layer. A device manufacturing method comprising a separation step of separating the work piece present at a position where the interface ablation occurs from the work handling sheet and placing the work piece on the object. According to clause 12,
A device manufacturing method characterized in that, in the preparation step, the work held on a side opposite to the substrate in the interfacial ablation layer is separated into pieces on the side to obtain the work pieces. According to claim 12 or 13,
A device manufacturing method, wherein the work piece is at least one type selected from semiconductor components and semiconductor devices. According to any one of claims 12 to 14,
A device manufacturing method characterized by manufacturing a light-emitting device having a plurality of light-emitting diodes by using light-emitting diodes selected from mini light-emitting diodes and micro light-emitting diodes as the work pieces. According to clause 15,
A device manufacturing method, wherein the light-emitting device is a display.