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

Abstract

[Problem] To provide a workpiece handling sheet with which it is possible to favorably handle even a very small workpiece item. [Solution] A workpiece handling sheet 1 is provided with a base material 11 and an interface ablation layer 12 that is laminated on one surface side of the base material 11, able to hold a small workpiece item, and undergoes interface ablation through irradiation with laser light. When the workpiece handling sheet 1 that has been subjected to first ultraviolet irradiation to perform irradiation with ultraviolet rays having a wavelength of 365 nm with a light amount of 190 mJ / cm2 is further subjected to second ultraviolet irradiation to perform irradiation with ultraviolet rays having a wavelength of 365 nm with a light amount of 950 mJ / cm2, the conversion efficiency with which the interface ablation layer 12 converts the light energy of the ultraviolet rays during the second ultraviolet irradiation into thermal energy is 60% or more.

Description

[Technical Field]

[0001] The present invention relates to a work handling sheet usable for handling small workpieces such as semiconductor components and semiconductor devices, a method for handling small workpieces using the work handling sheet, a method for manufacturing devices, and the use of the work handling sheet, and more particularly to a work handling sheet usable for handling small workpieces such as micro light-emitting diodes, power devices, and MEMS (Micro Electro Mechanical Systems). [Background technology]

[0002] In recent years, the development of displays using micro-light-emitting diodes (LEDs) has been progressing. In these displays, each pixel is composed of a micro-light-emitting diode, and the light emission of each micro-LED is controlled independently. In the manufacture of these displays, it is generally necessary to mount the micro-light-emitting diodes, which are placed on a supply substrate such as sapphire or glass, onto a wiring board with wiring.

[0003] During the above implementation, it is necessary to precisely mount multiple micro-light-emitting diodes (LEDs) placed on the supply board to their designated positions on the wiring board. At this time, it may be necessary to selectively mount specific LEDs from among the multiple LEDs onto the wiring board, or to mount multiple LEDs simultaneously.

[0004] From the perspective of successfully implementing such a method, the use of laser irradiation is being considered. For example, a method is being considered in which multiple microlight-emitting diodes are held on a support via a predetermined layer, and then laser light is irradiated onto the layer to cause ablation of the layer at the irradiated location, thereby separating the microlight-emitting diodes from the support (laser lift-off) and placing them on a wiring board (Patent Document 1). Because laser light has excellent directivity and focusing properties, the irradiation position can be easily controlled, and selective placement can be performed effectively.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, further miniaturization of micro light-emitting diodes and higher-density mounting of micro light-emitting diodes have also been advanced. In order to cope with these, means capable of more efficiently handling a large number of fine workpiece pieces such as micro light-emitting diodes compared to conventional methods such as Patent Document 1 are required.

[0007] The present invention has been made in view of such a situation, and an object thereof is to provide a work handling sheet that can handle even fine workpiece pieces well.

Means for Solving the Problems

[0008] To achieve the above object, first, the present invention provides a work handling sheet including a base material and an interfacial ablation layer laminated on one side of the base material, capable of holding a workpiece piece and undergoing interfacial ablation by irradiation with laser light. When the work handling sheet irradiated with first ultraviolet irradiation with ultraviolet light having a wavelength of 365 nm at a light amount of 190 mJ / cm<00,00090>, <00,00091>, <00,00089>is further irradiated with second ultraviolet irradiation with ultraviolet light having a wavelength of 365 nm at a light amount of 950 mJ / cm<00,00002>the conversion efficiency when the interfacial ablation layer converts the light energy of the ultraviolet light in the second ultraviolet irradiation into thermal energy is 60% or more. A work handling sheet is provided (Invention 1).

[0009] The work handling sheet according to the above invention (Invention 1) can effectively perform interfacial ablation when irradiated with laser light by the interfacial ablation layer exhibiting the above-described conversion efficiency, thereby enabling good separation of the work pieces toward the object.

[0010] In the above invention (Invention 1), it is preferable that the interfacial ablation layer is an adhesive layer composed of an active energy ray curable adhesive or a non-active energy ray curable adhesive (Invention 2).

[0011] In the above invention (Inventions 1 and 2), it is preferable that the interfacial ablation layer contains at least one additive such as an ultraviolet absorber and a photoinitiator (Invention 3).

[0012] In the above invention (Inventions 1 to 3), it is preferable that the laser light has a wavelength in the ultraviolet region (Invention 4).

[0013] In the above invention (Inventions 1 to 4), when interfacial ablation is caused in the interfacial ablation layer, it is preferable that blisters are formed at the position where the interfacial ablation has occurred (Invention 5).

[0014] In the above invention (Inventions 1 to 5), by curing the interfacial ablation layer entirely or locally by irradiation with active energy rays and causing local interfacial ablation in the interfacial ablation layer by irradiation with the laser light, any one of the plurality of work pieces held on the surface of the interfacial ablation layer opposite to the base material is preferably used for selectively separating from the interfacial ablation layer (Invention 6).

[0015] Secondly, the present invention provides a method for handling workpieces, comprising: a preparation step of preparing a laminate in which a plurality of workpieces are held on the surface of the interfacial ablation layer of the workpiece handling sheet (Inventions 1 to 6); a placement step of arranging the laminate on an object capable of receiving the workpieces such that the surfaces of the laminate on which the workpieces are held face to each other; and a separation step of irradiating a laser beam to a position on the interfacial ablation layer of the laminate where at least one of the workpieces is attached, thereby causing interfacial ablation at the irradiated position in the interfacial ablation layer, separating the workpieces located at the position where the interfacial ablation has occurred from the workpiece handling sheet, and placing the workpieces on the object (Invention 7).

[0016] Thirdly, the present invention provides a device manufacturing method (Invention 8) comprising: a preparation step of preparing a laminate in which a plurality of workpieces are held on the surface of the work handling sheet (Inventions 1 to 6) on the surface facing the interface ablation layer; a placement step of arranging the laminate on an object capable of receiving the workpieces such that the surfaces of the laminate on the workpieces face each other; and a separation step of irradiating a laser beam to a position on the interface ablation layer of the laminate where at least one of the workpieces is attached, thereby causing interface ablation at the irradiated position in the interface ablation layer, separating the workpieces located at the position where interface ablation has occurred from the work handling sheet, and placing the workpieces on the object.

[0017] Fourthly, the present invention provides a use for the work handling sheet (Inventions 1-6) for handling small pieces of work (Invention 9). [Effects of the Invention]

[0018] The work handling sheet according to the present invention can handle even minute workpieces effectively. [Brief explanation of the drawing]

[0019] [Figure 1] This is a cross-sectional view of a work handling sheet according to one embodiment of the present invention. [Figure 2] This is a cross-sectional view illustrating a method for handling workpieces and a device manufacturing method using a work handling sheet according to one embodiment of the present invention. [Figure 3] This is a cross-sectional view illustrating the state of the blister and reaction region created by laser light irradiation. [Modes for carrying out the invention]

[0020] Embodiments of the present invention will be described below. Figure 1 shows a cross-sectional view of a work handling sheet according to one embodiment. The work handling sheet 1 shown in Figure 1 comprises a base material 12 and an interface ablation layer 11 laminated on one side of the base material 12.

[0021] In the work handling sheet 1 according to this embodiment, the interface ablation layer 11 is capable of holding workpieces. That is, the work handling sheet 1 according to this embodiment can hold workpieces laminated on the surface of the interface ablation layer 11 opposite to the substrate 12 in that state.

[0022] Although the specific manner of retention described above is not limited, a preferred example is retention by the interfacial ablation layer 11 exhibiting adhesiveness to the workpiece piece. In this case, it is preferable that the interfacial ablation layer 11 contains an adhesive as one of its constituent components, as will be described later, i.e., it is an adhesive layer.

[0023] Furthermore, the interface ablation layer 11 in this embodiment undergoes interface ablation by irradiation with laser light. That is, the interface ablation layer 11 undergoes localized interface ablation in the region irradiated with the laser light. The laser light is not particularly limited as long as it is capable of causing interface ablation, and may have wavelengths in the ultraviolet, visible, or infrared regions, with a laser light having a wavelength in the ultraviolet region being preferred.

[0024] In this specification, interfacial ablation refers to the process in which some of the components constituting the interfacial ablation layer 11 evaporate or volatilize due to the energy of the laser light, and the resulting gas accumulates at the interface between the interfacial ablation layer 11 and the substrate 12, creating a void (blister). In this case, the shape of the interfacial ablation layer 11 changes due to the blister, causing the workpiece fragments to peel off from the interfacial ablation layer 11 and separate.

[0025] Furthermore, in the work handling sheet 1 according to this embodiment, ultraviolet light with a wavelength of 365 nm is emitted at a light intensity of 190 mJ / cm². 2 The work handling sheet 1, which had undergone a first ultraviolet irradiation using the method described above, was further irradiated with ultraviolet light at a wavelength of 365 nm at a rate of 950 mJ / cm². 2 When a second ultraviolet irradiation is performed with the specified light intensity, the conversion efficiency of the interface ablation layer 11 in converting the ultraviolet light energy from the second ultraviolet irradiation into thermal energy is 60% or more.

[0026] In the work handling sheet 1 according to this embodiment, by satisfying the above conversion efficiency, interface ablation occurs efficiently, making it possible to effectively separate the held workpiece fragments from the interface ablation layer 11. In particular, the amount of laser light required to achieve sufficient separation of the workpiece fragments is reduced, which reduces the operating cost of the laser light irradiation device, improves accuracy by making it easier to effectively separate only the target workpiece fragments, and also prevents damage to the device and workpiece fragments due to excessive laser light irradiation.

[0027] 1. Interface ablation layer The specific configuration and composition of the interface ablation layer 11 in this embodiment are not particularly limited, as long as they can hold the workpiece and satisfy the conversion efficiency described above.

[0028] As described above, the interface ablation layer 11 is preferably an adhesive layer, and in particular, the interface ablation layer 11 is preferably an adhesive layer composed of an adhesive having active energy ray curability (active energy ray curable adhesive) or an adhesive not having active energy ray curability (non-active energy ray curable adhesive).

[0029] Furthermore, from the viewpoint of easily satisfying the conversion efficiency described above, the interfacial ablation 11 preferably contains at least one additive, such as an ultraviolet absorber and a photopolymerization initiator.

[0030] (1) Active energy ray curable adhesive If the interface ablation layer 11 is an adhesive layer composed of an active energy ray curable adhesive, the adhesion between the work handling sheet 1 and the workpiece according to this embodiment can be reduced by irradiation with active energy rays. Therefore, by reducing the adhesion by irradiation with active energy rays before or simultaneously with the interface ablation described above, it becomes possible to reliably separate the workpiece from the work handling sheet 1 according to this embodiment. Furthermore, it becomes possible to further reduce the amount of laser light irradiation required to achieve sufficient separation of the workpiece. In addition, since the adhesion to the workpiece is reduced by irradiation with active energy rays in the work handling sheet 1 according to this embodiment, it is also possible to set the adhesion to a higher level before irradiation with active energy rays. As a result, when transferring workpieces from other sheets, etc. to the work handling sheet 1 according to this embodiment, it becomes possible to prevent the residue of workpieces on the other sheets, etc., and to perform a good transfer.

[0031] The above-mentioned active energy ray-curable adhesive may be any of the following: acrylic adhesive, rubber adhesive, silicone adhesive, urethane adhesive, polyester adhesive, polyvinyl ether adhesive, etc. However, from the viewpoint of easily exhibiting the desired adhesive strength, an acrylic adhesive is preferred.

[0032] Furthermore, the active energy ray curable adhesive may be mainly composed of an active energy ray curable polymer, or it may be mainly composed of a mixture of an active energy ray non-curable polymer (a polymer that does not possess active energy ray curability) and a monomer and / or oligomer having at least one active energy ray curable group. Alternatively, it may be a mixture of an active energy ray curable polymer and an active energy ray non-curable polymer, or a mixture of an active energy ray curable polymer and a monomer and / or oligomer having at least one active energy ray curable group, or a mixture of all three.

[0033] First, we will explain the case where the active energy ray-curable adhesive mainly consists of a polymer that is curable by active energy rays.

[0034] The polymer having active energy ray curability is preferably a (meth)acrylic acid ester (co)polymer (A) (hereinafter sometimes referred to as "active energy ray curable polymer (A)") in which an energy ray curable functional group (active energy ray curable group) is introduced into the side chain. This active energy ray curable polymer (A) is preferably obtained by reacting an acrylic copolymer (a1) having a functional group-containing monomer unit with an unsaturated group-containing compound (a2) having a functional group bonded to that functional group. In this specification, (meth)acrylic acid ester means both acrylic acid ester and methacrylic acid ester. The same applies to other similar terms.

[0035] The acrylic copolymer (a1) preferably contains structural units derived from functional group-containing monomers and structural units derived from (meth)acrylic acid ester monomers or their derivatives.

[0036] The functional group-containing monomer used as a constituent unit of the acrylic copolymer (a1) is preferably a monomer having a polymerizable double bond and a functional group such as a hydroxyl group, carboxyl group, amino group, substituted amino group, or epoxy group within its molecule.

[0037] Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate, which can be used individually or in combination of two or more.

[0038] Examples of carboxyl group-containing monomers include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. These may be used individually or in combination of two or more.

[0039] Examples of amino group-containing monomers or substituted amino group-containing monomers include aminoethyl (meth)acrylate and n-butylaminoethyl (meth)acrylate. These may be used individually or in combination of two or more.

[0040] As the (meth)acrylic acid ester monomer constituting the acrylic copolymer (a1), alkyl (meth)acrylates having 1 to 20 carbon atoms in the alkyl group are preferred, as well as monomers having an alicyclic structure in the molecule (alicyclic structure-containing monomers).

[0041] As alkyl (meth)acrylates, alkyl (meth)acrylates in which the alkyl group has 1 to 18 carbon atoms are particularly preferred, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. These may be used individually or in combination of two or more.

[0042] Preferred monomers containing alicyclic structures include, for example, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, adamantyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate. These may be used individually or in combination of two or more.

[0043] The acrylic copolymer (a1) contains structural units derived from the functional group-containing monomer in a proportion preferably of 1% by mass or more, particularly preferably of 5% by mass or more, and even more preferably of 10% by mass or more. Furthermore, the acrylic copolymer (a1) contains structural units derived from the functional group-containing monomer in a proportion preferably of 35% by mass or less, particularly preferably of 30% by mass or less, and even more preferably of 25% by mass or less.

[0044] Furthermore, the acrylic copolymer (a1) contains constituent units derived from (meth)acrylic acid ester monomers or their derivatives in a proportion preferably of 50% by mass or more, particularly preferably of 60% by mass or more, and even more preferably of 70% by mass or more. In addition, the acrylic copolymer (a1) contains constituent units derived from (meth)acrylic acid ester monomers or their derivatives in a proportion preferably of 99% by mass or less, particularly preferably of 95% by mass or less, and even more preferably of 90% by mass or less.

[0045] Acrylic copolymer (a1) can be obtained by copolymerizing a functional group-containing monomer as described above with a (meth)acrylic acid ester monomer or its derivative by a conventional method. In addition to these monomers, dimethylacrylamide, vinyl formate, vinyl acetate, styrene, etc., may also be copolymerized.

[0046] An active energy ray curable polymer (A) is obtained by reacting an acrylic copolymer (a1) having the above-mentioned functional group-containing monomer units with an unsaturated group-containing compound (a2) having a functional group bonded to the functional group.

[0047] The functional group of the unsaturated group-containing compound (a2) can be appropriately selected according to the type of functional group of the functional group-containing monomer unit of the acrylic copolymer (a1). For example, if the functional group of the acrylic copolymer (a1) is a hydroxyl group, an amino group, or a substituted amino group, the functional group of the unsaturated group-containing compound (a2) is preferably an isocyanate group or an epoxy group. If the functional group of the acrylic copolymer (a1) is an epoxy group, the functional group of the unsaturated group-containing compound (a2) is preferably an amino group, a carboxyl group, or an aziridinyl group.

[0048] Furthermore, the above-mentioned unsaturated group-containing compound (a2) contains at least one, preferably 1 to 6, and more preferably 1 to 4, energy-ray polymerizable carbon-carbon double bonds per molecule. Specific examples of such unsaturated group-containing compounds (a2) include, for example, 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1,1-(bisacryloyloxymethyl)ethyl isocyanate; acryloyl monoisocyanate compounds obtained by the reaction of a diisocyanate compound or polyisocyanate compound with hydroxyethyl (meth)acrylate; acryloyl monoisocyanate compounds obtained by the reaction of a diisocyanate compound or polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate; glycidyl (meth)acrylate; (meth)acrylic acid, 2-(1-aziridinyl)ethyl (meth)acrylate, 2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline, etc.

[0049] The above unsaturated group-containing compound (a2) is used in a ratio of preferably 50 mol% or more, particularly preferably 60 mol% or more, and even more preferably 70 mol% or more, relative to the number of moles of the functional group-containing monomer of the above acrylic copolymer (a1). Furthermore, the above unsaturated group-containing compound (a2) is used in a ratio of preferably 95 mol% or less, particularly preferably 93 mol% or less, and even more preferably 90 mol% or less, relative to the number of moles of the functional group-containing monomer of the above acrylic copolymer (a1).

[0050] In the reaction between the acrylic copolymer (a1) and the unsaturated group-containing compound (a2), the reaction temperature, pressure, solvent, time, presence or absence of a catalyst, and type of catalyst can be appropriately selected depending on the combination of functional groups present in the acrylic copolymer (a1) and the functional groups present in the unsaturated group-containing compound (a2). As a result, the functional groups present in the acrylic copolymer (a1) react with the functional groups in the unsaturated group-containing compound (a2), introducing unsaturated groups into the side chains of the acrylic copolymer (a1), and yielding an active energy ray-curable polymer (A).

[0051] The weight-average molecular weight (Mw) of the activated energy ray-curable polymer (A) obtained in this manner is preferably 10,000 or more, particularly preferably 100,000 or more, and even more preferably 150,000 or more. Furthermore, the weight-average molecular weight (Mw) is preferably 1,500,000 or less, particularly preferably 1,250,000 or less, and even more preferably 1,000,000 or less. In this specification, the weight-average molecular weight (Mw) is a value on a standard polystyrene basis measured by gel permeation chromatography (GPC).

[0052] Even if the active energy ray-curable adhesive mainly consists of an active energy ray-curable polymer (A), the active energy ray-curable adhesive may further contain an energy ray-curable monomer and / or oligomer (B).

[0053] As the active energy ray curable monomer and / or oligomer (B), for example, an ester of a polyhydric alcohol and (meth)acrylic acid can be used.

[0054] Examples of such active energy ray curable monomers and / or oligomers (B) include monofunctional acrylic acid esters such as cyclohexyl (meth)acrylate and isobornyl (meth)acrylate, polyfunctional acrylic acid esters such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and dimethylol tricyclodecane di(meth)acrylate, as well as polyester oligo(meth)acrylate and polyurethane oligo(meth)acrylate.

[0055] When an active energy ray-curable polymer (A) is combined with an active energy ray-curable monomer and / or oligomer (B), the content of the active energy ray-curable monomer and / or oligomer (B) in the active energy ray-curable adhesive is preferably more than 0 parts by mass, and particularly preferably 60 parts by mass or more, per 100 parts by mass of the active energy ray-curable polymer (A). Furthermore, the content is preferably 250 parts by mass or less, and particularly preferably 200 parts by mass or less, per 100 parts by mass of the active energy ray-curable polymer (A).

[0056] Next, we will explain the case where the active energy ray-curable adhesive mainly consists of a mixture of an active energy ray-noncurable polymer component and a monomer and / or oligomer having at least one active energy ray-curable group.

[0057] As the active energy ray non-curing polymer component, for example, the same component as the acrylic copolymer (a1) described above can be used.

[0058] The monomer and / or oligomer having at least one active energy ray curable group can be the same as component (B) described above. The blending ratio of the active energy ray non-curable polymer component to the monomer and / or oligomer having at least one active energy ray curable group is preferably 1 part by mass or more of the monomer and / or oligomer having at least one active energy ray curable group per 100 parts by mass of the active energy ray non-curable polymer component, and particularly preferably 60 parts by mass or more. Furthermore, the blending ratio is preferably 200 parts by mass or less of the monomer and / or oligomer having at least one active energy ray curable group per 100 parts by mass of the active energy ray non-curable polymer component, and particularly preferably 160 parts by mass or less.

[0059] (2) Non-reactive energy ray curable adhesive If the interfacial ablation layer 11 is an adhesive layer composed of an inactive energy ray curable adhesive, the adhesive may be any of the following: acrylic adhesive, rubber adhesive, silicone adhesive, urethane adhesive, polyester adhesive, polyvinyl ether adhesive, etc. However, from the viewpoint of easily exhibiting the desired adhesive strength, an acrylic adhesive is preferred.

[0060] An example of an acrylic adhesive used as a non-active energy ray curable adhesive is an adhesive containing the active energy ray non-curable polymer component described above. The active energy ray non-curable polymer component can also be the same component as the acrylic copolymer (a1) described above. The non-active energy ray curable adhesive does not contain the active energy ray curable polymer described above, nor the monomers and / or oligomers having at least one active energy ray curable group described above.

[0061] (3) Additives As described above, the interfacial ablation 11 in this embodiment preferably contains at least one additive, such as an ultraviolet absorber and a photopolymerization initiator, from the viewpoint of easily satisfying the aforementioned conversion efficiency.

[0062] (3-1) UV absorbers The type of UV absorber in this embodiment is not particularly limited. The UV absorber in this embodiment may be an organic compound or an inorganic compound, but an organic compound is preferred from the viewpoint of easily generating good interfacial ablation.

[0063] When the UV absorber is an organic compound, preferred examples of such UV absorbers include hydroxyphenyltriazine-based UV absorbers, benzophenone-based UV absorbers, benzotriazole-based UV absorbers, benzoate-based UV absorbers, benzoxazinon-based UV absorbers, phenylsalicylate-based UV absorbers, cyanoacrylate-based UV absorbers, nickel complex salt-based UV absorbers, hydroquinone-based UV absorbers, salicylic acid-based UV absorbers, malonic acid ester-based UV absorbers, and oxalic acid-based UV absorbers. These may be used individually or in combination of two or more.

[0064] Among the UV absorbers mentioned above, it is preferable to use at least one of the following: a hydroxyphenyltriazine-based UV absorber, a benzophenone-based UV absorber, and a benzotriazole-based UV absorber, from the viewpoint of having good absorption at the third harmonic of YAG (355 nm) and readily generating good interfacial ablation. In particular, it is preferable to use a hydroxyphenyltriazine-based UV absorber.

[0065] The above hydroxyphenyltriazine-based UV absorbers include 2-[4-(octyl-2-methylethanolate)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)]-1,3,5-triazine, 2-[4-(2-hydroxy-3-dodecyloxypropyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-(2-hydroxy-3-tridecyloxypropyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine, Examples include 2-[4-(2-hydroxy-3-(2'-ethyl)hexyloxy]-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3-5-triazine, 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, and tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine. These may be used individually or in combination of two or more.

[0066] Among these, it is preferable to use at least one of tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine, 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, 2-[4-(2-hydroxy-3-dodecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2-[4-(2-hydroxy-3-tridecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine].

[0067] Furthermore, if the UV absorber is an organic compound, it is preferable that the UV absorber has one or more heterocycles as a characteristic of its chemical structure. In this case, the number of heterocycles is preferably four or less, and particularly preferably one.

[0068] Furthermore, as another characteristic of the chemical structure, it is preferable that the ultraviolet absorber in this embodiment has at least one of a carbocyclic ring and a heterocyclic ring, and that all of the carbocyclic rings and heterocyclic rings in the ultraviolet absorber are monocyclic rings.

[0069] As a further characteristic of the chemical structure, the ultraviolet absorber in this embodiment is preferably a compound having multiple aromatic rings. In this case, the number of aromatic rings is preferably two or more. Furthermore, the number of aromatic rings is preferably six or less, and particularly preferably three or less.

[0070] In the chemical structural characteristics described above, each heterocycle preferably has at least one element other than carbon selected from nitrogen, oxygen, phosphorus, sulfur, silicon, and selenium, and is particularly preferably at least one selected from nitrogen, oxygen, phosphorus, and sulfur. Furthermore, there is no particular limit to the number of atoms constituting the ring structure of the heterocycle; for example, it is preferably 3 to 9, and particularly preferably 5 to 6. Specific examples of preferred heterocycles include triazine, benzotriazole, thiophene, pyrrole, imidazole, pyridine, and pyrazine.

[0071] Furthermore, regarding the chemical structural characteristics described above, preferred examples of aromatic rings include benzene, naphthalene, anthracene, biphenyl, and triphenyl.

[0072] An example of an ultraviolet absorber having the chemical structural characteristics described above is tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine).

[0073] In this embodiment, when the interfacial ablation layer 11 contains an ultraviolet absorber, the content of the ultraviolet absorber in the interfacial ablation layer 11 is preferably 1% by mass or more, particularly preferably 3% by mass or more, and even more preferably 5% by mass or more. A content of 1% by mass or more of ultraviolet absorber allows the interfacial ablation layer 11 to efficiently absorb laser light, thereby facilitating good interfacial ablation. Furthermore, the content of the ultraviolet absorber in the interfacial ablation layer 11 is preferably 75% by mass or less, particularly preferably 40% by mass or less, and even more preferably 25% by mass or less. A content of 75% by mass or less of ultraviolet absorber results in an appropriate viscosity for the material used to form the interfacial ablation layer 11, making it easier to ensure good film-forming properties.

[0074] Furthermore, if the interfacial ablation layer 11 in this embodiment is formed from an adhesive composition described later, the ultraviolet absorber may be incorporated into this adhesive composition. In that case, the amount of ultraviolet absorber incorporated into the adhesive composition is preferably 1% by mass or more, particularly preferably 3% by mass or more, and even more preferably 5% by mass or more. By incorporating 1% by mass or more of ultraviolet absorber, the interfacial ablation layer 11 efficiently absorbs laser light, thereby facilitating good interfacial ablation. Furthermore, by incorporating 75% by mass or less of ultraviolet absorber into the adhesive composition, the resulting adhesive is more likely to exhibit the desired adhesive strength.

[0075] (3-2) Photopolymerization initiator The photopolymerization initiator in this embodiment is not particularly limited. When the interfacial ablation layer 11 is an adhesive layer composed of an active energy ray curable adhesive, it is preferable that the interfacial ablation layer 11 contains a photopolymerization initiator. In this case, efficient interfacial ablation is more easily achieved, and the interfacial ablation layer 11 hardens efficiently.

[0076] Examples of photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, and 1-hydroxycyclo Hexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-phenyl)butan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxymethylpropanone, ethanone, 1-[9-ethyl-6-(2-methylbenzo [Iyl]-9H-carbazole-3-yl]-,1-(O-acetyloxime), benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiary-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone Examples include oxantone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, oligo[2-hydroxy-2-methyl-1[4-(1-methylvinyl)phenyl]propanone], 2-benzyl-2-(dimethylamino)-4'-morpholinobylophenone, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. These may be used individually or in combination of two or more.

[0077] Among the photopolymerization initiators mentioned above, it is preferable to use at least one of the following: 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one, ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(0-acetyloxime), 2-benzyl-2-(dimethylamino)-4'-morpholinobylophenone, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and 2,2-dimethoxy-1,2-diphenylethane-1-one.

[0078] In this embodiment, when the interfacial ablation layer 11 contains a photopolymerization initiator, the content of the photopolymerization initiator in the interfacial ablation layer 11 is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more. A photopolymerization initiator content of 1% by mass or more allows the interfacial ablation layer 11 to efficiently absorb laser light, thereby facilitating good interfacial ablation. Furthermore, the photopolymerization initiator content in the interfacial ablation layer 11 is preferably 75% by mass or less, more preferably 40% by mass or less, and even more preferably 25% by mass or less. A photopolymerization initiator content of 75% by mass or less results in an appropriate viscosity for the material used to form the interfacial ablation layer 11, making it easier to ensure good film formation.

[0079] Furthermore, if the interfacial ablation layer 11 in this embodiment is formed from an adhesive composition described later, the photopolymerization initiator may be incorporated into this adhesive composition. In that case, the amount of photopolymerization initiator in the adhesive composition is preferably 1% by mass or more, particularly preferably 3% by mass or more, and even more preferably 5% by mass or more. By incorporating 1% by mass or more of the photopolymerization initiator, the interfacial ablation layer 11 efficiently absorbs laser light, thereby facilitating good interfacial ablation. Furthermore, by incorporating 75% by mass or less of the photopolymerization initiator in the adhesive composition, the amount of photopolymerization initiator is preferably 75% by mass or less, particularly preferably 40% by mass or less, and even more preferably 25% by mass or less. By incorporating 75% by mass or less of the photopolymerization initiator, the resulting adhesive is more likely to exhibit the desired adhesive strength.

[0080] (4) Other ingredients The adhesive constituting the interfacial ablation layer 11 according to this embodiment may contain other components as appropriate. Examples of other components include crosslinking agents, active energy ray non-curing polymer components, or oligomer components.

[0081] The use of a crosslinking agent is preferable from the viewpoint of easily adjusting the storage modulus of the interfacial ablation layer 11 to a desired range. As the crosslinking agent, a polyfunctional compound that has reactivity with the functional groups of the active energy ray curable polymer (A) or acrylic copolymer (a1) can be used. Examples of such polyfunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts, and reactive phenolic resins.

[0082] The amount of crosslinking agent is preferably 0.001 parts by mass or more, particularly preferably 0.1 parts by mass or more, and more preferably 0.2 parts by mass or more, per 100 parts by mass of the main component. Furthermore, the amount of crosslinking agent is preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of the main component. The above-mentioned "main component" refers to the above-mentioned active energy ray curable polymer (A) when the interfacial ablation layer 11 is composed of an active energy ray curable adhesive, and refers to the above-mentioned acrylic copolymer (a1) when the interfacial ablation layer 11 is composed of a non-active energy ray curable adhesive.

[0083] Examples of the active energy ray non-curing polymer or oligomer components mentioned above include polyacrylic acid esters, polyesters, polyurethanes, polycarbonates, and polyolefins, with polymers or oligomers having a weight-average molecular weight (Mw) of 3,000 to 2,500,000 being preferred. By incorporating these components, tackiness, release properties, adhesion to other layers, and storage stability can be improved.

[0084] (5) Thickness of the interfacial ablation layer In this embodiment, the thickness of the interface ablation layer 11 is preferably 3 μm or more, particularly preferably 20 μm or more, and even more preferably 25 μm or more. Furthermore, the thickness of the interface ablation layer 11 is preferably 100 μm or less, particularly preferably 50 μm or less, and even more preferably 40 μm or less. Having the thickness of the interface ablation layer 11 within the above range makes it easier to achieve both the retention of workpiece pieces on the interface ablation layer 11 and the separation of workpiece pieces by interface ablation.

[0085] 2. Base material The base material 12 in this embodiment is not particularly limited in terms of its composition or physical properties. From the viewpoint of making it easier for the work handling sheet 1 to perform the desired function, it is preferable that the base material 12 be made of a resin. When the base material 12 is made of a resin, examples of such resins include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resins such as polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, ethylene-norbornene copolymer, and norbornene resin; ethylene-vinyl acetate copolymer; ethylene copolymer resins such as ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate copolymer, and other ethylene-(meth)acrylic acid ester copolymers; polyvinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer; (meth)acrylic acid ester copolymer; polyurethane; polyimide; polystyrene; polycarbonate; and fluororesin. Furthermore, the resin constituting the base material 12 may be a crosslinked version of the above-mentioned resins or a modified version such as an ionomer of the above-mentioned resins. Furthermore, the base material 12 may be a single-layer film made of the resin described above, or it may be a laminated film formed by laminating multiple such films. In this laminated film, the materials constituting each layer may be of the same type or different types.

[0086] In this embodiment, the surface of the substrate 12 may be subjected to surface treatment such as oxidation or embossing, or primer treatment, in order to improve adhesion to the interfacial ablation layer 11. Examples of oxidation methods include corona discharge treatment, plasma discharge treatment, chromium oxidation (wet), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment. Examples of embossing methods include sandblasting and thermal spraying.

[0087] In this embodiment, the substrate 12 may contain various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, and fillers. Furthermore, if the interfacial ablation layer 11 contains a material that hardens with active energy rays, it is preferable that the substrate 12 is permeable to active energy rays.

[0088] The method for manufacturing the base material 12 in this embodiment is not particularly limited as long as it is manufactured from a resin. For example, it can be manufactured by forming the resin into a sheet using a melt extrusion method such as a T-die method or a circular die method; a calendering method; a solution method such as a dry method or a wet method.

[0089] In this embodiment, the thickness of the base material 12 is preferably 10 μm or more, particularly preferably 30 μm or more, and even more preferably 50 μm or more. Furthermore, the thickness of the base material 12 is preferably 500 μm or less, more preferably 300 μm or less, particularly preferably 200 μm or less, even more preferably 150 μm or less, and most preferably 100 μm or less. When the thickness of the base material 12 is within the above range, the work handling sheet 1 will have a predetermined balance of rigidity and flexibility, making it easier to handle small workpieces well.

[0090] 3. Release sheet In this embodiment, if the interface ablation layer 11 includes an adhesive as one of its constituent components, a release sheet may be laminated on the surface of the interface ablation layer 11 opposite to the substrate 12 for the purpose of protecting that surface until it is attached to the workpiece.

[0091] The composition of the release sheet described above is arbitrary, and an example is a plastic film that has been treated with a release agent. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, silicone-based, fluorine-based, and long-chain alkyl-based agents can be used, and among these, silicone-based agents are preferred because they are inexpensive and provide stable performance.

[0092] There are no particular restrictions on the thickness of the release sheet mentioned above; for example, it may be between 20 μm and 250 μm.

[0093] 4. Other configurations In the work handling sheet 1 according to this embodiment, an adhesive layer may be laminated on the side of the interface ablation layer 11 opposite to the substrate 12. In this sheet, a workpiece can be attached to the side of the adhesive layer opposite to the interface ablation layer 11, and by dicing the adhesive layer together with the workpiece, a workpiece piece can be obtained in which individualized adhesive layers are laminated. The chip can be easily fixed to the object on which the workpiece piece is mounted by these individualized adhesive layers. As the material constituting the adhesive layer described above, it is preferable to use one that contains a thermoplastic resin and a low molecular weight thermosetting adhesive component, or one that contains a B-stage (semi-cured) thermosetting adhesive component.

[0094] Furthermore, in the work handling sheet 1 according to this embodiment, a protective film forming layer may be laminated on the side of the interface ablation layer 11 opposite to the substrate 12. In such a sheet, a workpiece can be attached to the side of the protective film forming layer opposite to the interface ablation layer 11, and the protective film forming layer can be diced together with the workpiece to obtain workpiece pieces with laminated individual protective film forming layers. Preferably, a workpiece with a circuit formed on one side is used, and in this case, the protective film forming layer is usually laminated on the side opposite to the side with the circuit. By curing the individual protective film forming layers at a predetermined timing, a protective film with sufficient durability can be formed on the workpiece pieces. Preferably, the protective film forming layer is made of an uncured curable adhesive.

[0095] 5. Physical properties of work handling sheets (1) Conversion efficiency In the work handling sheet 1 according to this embodiment, as described above, ultraviolet light with a wavelength of 365 nm is used at a light intensity of 190 mJ / cm². 2 The work handling sheet 1, which had undergone a first ultraviolet irradiation using the method described above, was further irradiated with ultraviolet light at a wavelength of 365 nm at a rate of 950 mJ / cm². 2 When a second ultraviolet irradiation is performed with a light intensity of , the conversion efficiency of the interface ablation layer 11 in converting the light energy of the ultraviolet in the second ultraviolet irradiation into thermal energy (hereinafter sometimes referred to as "conversion efficiency after ultraviolet irradiation") is 60% or more. This makes it possible to efficiently generate interface ablation and to separate the held workpiece pieces well from the interface ablation layer 11. From the viewpoint of enabling better separation, the above conversion efficiency is preferably 65% ​​or more, and particularly preferably 75% or more. The upper limit of the above conversion efficiency is not particularly limited, and may be, for example, 99% or less, particularly 97% or less, and even 95% or less.

[0096] In addition, in the work handling sheet 1 according to the present embodiment, (without performing the above-described first ultraviolet irradiation), when irradiated with ultraviolet light having a wavelength of 365 nm at a light amount of 950 mJ / cm 2 the conversion efficiency (hereinafter, may be referred to as "conversion efficiency before ultraviolet irradiation") when the interface ablation layer 11 converts the light energy of the above ultraviolet light into thermal energy is preferably 70% or more, particularly preferably 75% or more, and more preferably 80% or more. Thereby, it becomes easier to adjust the conversion efficiency after ultraviolet irradiation to the above-described range. Note that the upper limit value of the conversion efficiency before ultraviolet irradiation is not particularly limited, and may be, for example, 100% or less, particularly 97% or less, and more preferably 95% or less.

[0097] In addition, in the work handling sheet 1 according to the present embodiment, (without performing the above-described first ultraviolet irradiation), when irradiated with ultraviolet light having a wavelength of 365 nm at a light amount of 950 mJ / cm 2 the conversion efficiency (hereinafter, may be referred to as "conversion efficiency of the work handling sheet 1") when the work handling sheet 1 converts the light energy of the above ultraviolet light into thermal energy is preferably 70% or more, particularly preferably 80% or more, and more preferably 85% or more. Thereby, it becomes easier for the conversion efficiency after ultraviolet irradiation to satisfy the above-described range. Note that the upper limit value of the conversion efficiency of the work handling sheet 1 is not particularly limited, and may be, for example, 99% or less, particularly 97% or less, and more preferably 95% or less.

[0098] Note that the details of the above conversion efficiency measurement method are as described in the test examples described later.

[0099] (2) Heat generation amount In the work handling sheet 1 according to the present embodiment, with respect to the work handling sheet 1 that has been subjected to the first ultraviolet irradiation by irradiating ultraviolet light having a wavelength of 365 nm at a light amount of 190 mJ / cm 2 further, ultraviolet light having a wavelength of 365 nm is irradiated at 950 mJ / cm 2When a second ultraviolet irradiation is performed with a light intensity of 500 mJ / cm², the heat generated by the work handling sheet 1 is 500 mJ / cm². 2 Preferably, it is 600 mJ / cm² or higher, and especially 600 mJ / cm². 2 Preferably, it should be above 700 mJ / cm², and more preferably 700 mJ / cm². 2 The above is preferable. This allows for efficient interfacial ablation and enables better separation of the held workpiece fragments from the interfacial ablation layer 11. The upper limit of the heat generation is not particularly limited, for example, 2000 mJ / cm². 2 The following may be the case, especially 1500 mJ / cm² 2 The following may be true, and furthermore, 1000 mJ / cm² 2 The following is acceptable:

[0100] Furthermore, in the work handling sheet 1 according to this embodiment, ultraviolet light with a wavelength of 365 nm is emitted at a rate of 950 mJ / cm² (without performing the first ultraviolet irradiation described above). 2 When irradiated with this light intensity, the heat generated by the work handling sheet 1 is 600 mJ / cm². 2 Preferably, it should be above 700 mJ / cm², and especially 700 mJ / cm². 2 Preferably, it should be above 800 mJ / cm², and even more preferably 800 mJ / cm². 2 The above is preferable. This allows for efficient interfacial ablation and enables better separation of the held workpiece fragments from the interfacial ablation layer 11. The upper limit of the heat generation is not particularly limited, for example, 2000 mJ / cm². 2 The following may be the case, especially 1500 mJ / cm² 2 The following may be true, and furthermore, 1000 mJ / cm² 2 The following is acceptable:

[0101] Furthermore, in the work handling sheet 1 according to this embodiment, the substrate 12 alone is exposed to ultraviolet light with a wavelength of 365 nm at a rate of 950 mJ / cm² (without performing the first ultraviolet irradiation described above). 2 When irradiated with a light intensity of 1 mJ / cm², the amount of heat generated by the substrate 12 is 1 mJ / cm². 2It is preferable that it be greater than or equal to 5 mJ / cm², and particularly 5 mJ / cm². 2 Preferably, it should be 10 mJ / cm² or higher, and even more preferably 10 mJ / cm². 2 It is preferable that the above conditions are met. It is also preferable that the substrate 12 exhibits such a heat generation, as this contributes to efficient interfacial ablation. The upper limit of the heat generation is not particularly limited, for example, 100 mJ / cm². 2 The following may be the case, especially 90 mJ / cm² 2 It may be less than or equal to 80 mJ / cm², and furthermore 80 mJ / cm². 2 The following is acceptable:

[0102] Further details regarding the method for measuring the heat output are described in the test examples below.

[0103] (3) Absorbance The work handling sheet 1 according to this embodiment preferably has an absorbance of 0.5 or higher, more preferably 2.0 or higher, particularly preferably 2.5 or higher, and even more preferably 3.0 or higher, when it emits light with a wavelength of 355 nm. An absorbance of 0.5 or higher when it emits light with a wavelength of 355 nm reduces the amount of ultraviolet light reaching the workpiece during laser irradiation, effectively suppressing surface damage to the workpiece while separating it. The upper limit of the absorbance is not particularly limited and may be, for example, 6.0 or lower. Details of the method for measuring the absorbance are described in the test examples below.

[0104] 6. Method for manufacturing a work handling sheet The method for manufacturing the work handling sheet 1 according to this embodiment is not particularly limited. For example, the interface ablation layer 11 may be formed directly on the substrate 12, or the interface ablation layer 11 may be formed on a process sheet and then transferred onto the substrate 12.

[0105] If the interfacial ablation layer 11 contains an adhesive as one of its constituent components, the formation of the interfacial ablation layer 11 can be carried out by known methods. For example, a coating solution containing an adhesive composition for forming the interfacial ablation layer 11, and optionally a solvent or dispersion medium, can be prepared. Then, the coating solution can be applied to one side of the substrate or the release surface of the release sheet (hereinafter sometimes referred to as the "release surface"). Subsequently, the resulting coating film can be dried to form the interfacial ablation layer 11.

[0106] The coating solution described above can be applied by known methods, such as bar coating, knife coating, roll coating, blade coating, die coating, gravure coating, etc. The properties of the coating solution are not particularly limited as long as it can be applied, and it may contain components for forming the interface ablation layer 11 as a solute or as a dispersed phase. Furthermore, if the interface ablation layer 11 is formed on a release sheet, the release sheet may be peeled off as a process material, or it may protect the interface ablation layer 11 until it is attached to the adherend.

[0107] If the adhesive composition for forming the interfacial ablation layer 11 contains the aforementioned crosslinking agent, it is preferable to promote the crosslinking reaction between the polymer components in the coating film and the crosslinking agent by changing the drying conditions (temperature, time, etc.) or by separately performing a heat treatment, thereby forming a crosslinked structure with a desired density within the interfacial ablation layer 11. Furthermore, in order to allow the above-mentioned crosslinking reaction to proceed sufficiently, curing may be performed after the completion of the work handling sheet 1, for example, by leaving it undisturbed in an environment of 23°C and 50% relative humidity for several days.

[0108] 7. How to use the work handling sheet The work handling sheet 1 according to this embodiment can be suitably used for handling small workpieces. As described above, in the work handling sheet 1 according to this embodiment, the interface ablation layer 11 is efficiently subjected to interface ablation by irradiation with laser light, so that small workpieces held on the interface ablation layer 11 can be separated to predetermined positions with high precision.

[0109] One example of how to use the work handling sheet 1 according to this embodiment is to selectively separate any work piece from the interface ablation layer 11 by locally generated interface ablation in the interface ablation layer 11, which is held on the surface of the interface ablation layer 11 opposite to the substrate 12.

[0110] In the above method of use, the multiple workpiece pieces held on the interface ablation layer 11 may be obtained by dicing a workpiece (the material for the workpiece pieces) held on the surface of the interface ablation layer 11 opposite to the substrate 12 on that surface. That is, the workpiece pieces may be obtained by dicing a workpiece on the interface ablation layer 11. Alternatively, the workpiece pieces may be formed independently of the workpiece handling sheet 1 according to this embodiment and placed on the interface ablation layer 11.

[0111] Furthermore, if the work handling sheet 1 according to this embodiment includes the aforementioned adhesive layer and protective film forming layer, it is preferable to dic these layers and the workpiece on the interface ablation layer 11. This makes it possible to obtain workpiece pieces in which these layers are individually separated and laminated.

[0112] The shape and size of the workpiece pieces in this embodiment are not particularly limited, but in terms of size, the workpiece pieces have an area of ​​10 μm when viewed from above. 2 Preferably, it is 100 μm or more, and especially 100 μm2 It is preferable that the above conditions are met. Furthermore, the workpiece piece has an area of ​​1 mm when viewed from above. 2 Preferably the following, and especially 0.25 mm 2 The following is preferable. Furthermore, regarding the dimensions of the workpiece, if the workpiece is rectangular, the smallest side of the workpiece is preferably 2 μm or more, particularly preferably 5 μm or more, and even more preferably 10 μm or more. Furthermore, the smallest side is preferably 1 mm or less, particularly preferably 0.5 mm or less. Specific examples of the dimensions of a rectangular workpiece include 2 μm × 5 μm, 10 μm × 10 μm, 0.5 mm × 0.5 mm, 1 mm × 1 mm, etc. The workpiece handling sheet 1 according to this embodiment can handle such fine workpieces well, especially fine workpieces that are difficult to separate from the sheet by needle thrusting. On the other hand, the workpiece handling sheet 1 according to this embodiment has an area of ​​1 mm 2 Anything exceeding (for example, 1 mm) 2 ~2000mm 2 It can also handle relatively large workpieces, such as those with a thickness of 1 to 10,000 μm (for example, 10 to 1,000 μm), with good performance.

[0113] Examples of workpiece 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 workpiece piece is preferably a light-emitting diode, and in particular, it is 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 has been considered, and in the manufacture of such devices, the workpiece handling sheet 1 according to this embodiment, which can handle these light-emitting diodes with high precision, is very suitable.

[0114] Below, as a specific example of the use of Work Handling Sheet 1, a method for handling workpieces and a method for manufacturing devices will be described based on Figure 2. These methods comprise at least four steps: a preparation step (Figure 2(a)), a placement step (Figure 2(b)), a curing step (Figure 2(c)), and a separation step (Figures 2(d) and (e)).

[0115] In the preparation step, as shown in Figure 2(a), a laminate is prepared in which a plurality of workpiece pieces 2 are held on the surface of the work handling sheet 1 according to this embodiment, on the side facing the interface ablation layer 11. This laminate may be prepared by placing separately prepared workpiece pieces 2 on the work handling sheet 1, or by dicing the workpieces held on the surface facing the interface ablation layer 11. This dicing can be carried out by known methods.

[0116] As mentioned above, there are no particular limitations on the shape or size of the workpiece 2, and the preferred size is also as mentioned above. Specific examples of workpiece 2 include semiconductor components and semiconductor devices, as mentioned above, and in particular, light-emitting diodes such as miniature and microature light-emitting diodes.

[0117] In the subsequent arrangement step, as shown in Figure 2(b), the laminate is positioned so that the side of the laminate facing the workpiece 2 is facing the object 3 capable of receiving the workpiece 2. The object 3 is determined appropriately depending on the device to be manufactured, but when the workpiece 2 is a light-emitting diode, specific examples of the object 3 include substrates, sheets, reels, etc., and a wiring board with wiring is particularly preferred.

[0118] Subsequently, in the curing process, as shown in Figure 2(c), the entire interface ablation layer 11 in the laminate is irradiated with active energy rays 4 to cure the interface ablation layer 11 as a whole. As a result, the interface ablation layer 11 becomes a cured interface ablation layer 11'. Although Figure 2(c) depicts the irradiation of the entire interface ablation layer 11 with active energy rays 4, the irradiation may be performed only on the interface ablation layer 11 at the location where at least one workpiece 2 is attached, thereby curing the interface ablation layer 11 locally.

[0119] The irradiation with the activated energy rays 4 described above may be carried out using known methods. 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, which is also used in the separation process described later, may be used.

[0120] Subsequently, in the separation process, as shown in Figure 2(d), laser light 5 is first irradiated onto the location where at least one workpiece 2 is attached in the hardened interface ablation layer 11' of the laminate. This irradiation may be performed simultaneously on multiple locations where workpiece 2 is attached, or it may be performed sequentially on those locations. The irradiation conditions for the laser light 5 are not limited as long as they are capable of causing interface ablation. Known laser irradiation devices can be used for irradiation.

[0121] Furthermore, when both the irradiation with the active energy ray 4 in the curing process and the irradiation with the laser light 5 in the separation process are performed using the laser light irradiation device described above, the curing process and the separation process may be performed simultaneously. That is, the irradiation with the laser light 5 in the separation process may also serve as the irradiation with the active energy ray 4 in the curing process, thereby simultaneously performing local curing and interface ablation of the interface ablation layer 11. In this case, the peak wavelength of the irradiated laser light 5 is preferably 300 nm or more, particularly preferably 310 nm or more, and even more preferably 350 nm or more. In addition, the peak wavelength is preferably 400 nm or less, particularly preferably 390 nm or less, and even more preferably 380 nm or less. Irradiating with laser light 5 having such a wavelength makes it easier to promote good curing and interface ablation of the interface ablation layer 11.

[0122] On the other hand, as shown in Figure 2, when the curing process and the separation process are carried out as independent processes, the active energy rays 4 irradiated from the ultraviolet irradiation device (particularly a device equipped with an ultraviolet LED as a light source, and a laser light irradiation device) used in the curing process preferably have a peak wavelength of 300 nm or more, more preferably 310 nm or more, and even more preferably 320 nm or more. Furthermore, the peak wavelength is preferably 400 nm or less, particularly preferably 390 nm or less, and even more preferably 380 nm or less. Similarly, the laser light 5 irradiated from the laser light irradiation device used in the separation process preferably has a peak wavelength of 300 nm or more, particularly preferably 310 nm or more, and even more preferably 320 nm or more. Furthermore, the peak wavelength is preferably 400 nm or less, particularly preferably 390 nm or less, and even more preferably 380 nm or less. By irradiating the surface with the active energy rays 4 and laser light 5 having the peak wavelengths described above during the curing and separation processes, respectively, the curing and ablation of the interface ablation layer 11 can be easily facilitated in each process.

[0123] As shown in Figure 2(e), irradiation with the laser light 5 described above can cause interfacial ablation at the irradiated location in the hardened interfacial ablation layer 11'. Specifically, irradiation with the laser light 5 causes the components constituting the region of the hardened interfacial ablation layer 11' proximal to the substrate 12 to evaporate or volatilize, forming a reaction region 13. The gas generated by the evaporation or volatilization then accumulates between the substrate 12 and the reaction region 13, forming a blister 6. The formation of the blister 6 causes the hardened interfacial ablation layer 11' to deform locally at the location of the workpiece 2', causing the workpiece 2' to separate as it peels off from the hardened interfacial ablation layer 11'. As a result, the workpiece 2' located at the location where the interfacial ablation occurred can be placed on the object 3.

[0124] The reaction region 13 and blister 6 generated by the irradiation of the laser light 5 usually remain even after the separation of the workpiece 2'. Figure 3 shows the process of separating the workpiece 2 by sequentially irradiating it with laser light, and in particular, the state after separation (two on the left), the state during separation (center), and the state before separation (two on the right) are shown. As shown in the figure, the blister 6 after separation is usually somewhat deflated compared to the blister 6 during separation.

[0125] According to the method described above, various devices can be manufactured by appropriately selecting the workpiece 2 and object 3 to be used. For example, if a light-emitting diode selected from mini light-emitting diodes and micro light-emitting diodes is used as the workpiece 2, a light-emitting device equipped with multiple such light-emitting diodes can be manufactured, and more specifically, a display can be manufactured. In particular, a display equipped with micro light-emitting diodes as pixels, or a display equipped with multiple mini light-emitting diodes as a backlight can be manufactured.

[0126] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit it. Accordingly, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0127] For example, other layers may be laminated between the interface ablation layer 11 and the substrate 12 in the work handling sheet 1 according to this embodiment, or on the surface of the substrate 12 opposite to the interface ablation layer 11. A specific example of such other layer is an adhesive layer. In this case, the separation process described above can be performed with the side with the adhesive layer attached to a support base (a transparent substrate such as a glass plate). [Examples]

[0128] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0129] [Example 1] (1) Preparation of adhesive composition 80 parts by mass of 2-ethylhexyl acrylate and 20 parts by mass of 2-hydroxyethyl acrylate were polymerized by solution polymerization to obtain a (meth)acrylic acid ester polymer. The weight-average molecular weight (Mw) of this acrylic polymer was measured by the method described above and was found to be 600,000.

[0130] 100 parts by mass (based on solid content, the same applies hereafter) of the acrylic polymer obtained above, 0.94 parts by mass of trimethylolpropane-modified tolylene diisocyanate (manufactured by Tosoh Corporation, trade name "Coronate L") as a crosslinking agent, and 10 parts by mass of tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine (hydroxyphenyltriazine-based ultraviolet absorber, manufactured by BASF, product name "Tinuvin 477") as an additive were mixed in a solvent to obtain a coating solution for an adhesive composition.

[0131] (2) Formation of an interfacial ablation layer (adhesive layer) A release sheet (Lintec Corporation, product name "SP-PET381031"), which has a silicone-based release agent layer formed on one side of a 38 μm thick polyethylene terephthalate film, was coated with the adhesive composition solution obtained in step (1) above, and the resulting coating film was dried by heating. This resulted in a laminate in which a 5 μm thick interfacial ablation layer formed by the drying of the coating film and the release sheet were laminated together.

[0132] (3) Preparation of work handling sheet By bonding the interfacial ablation layer side of the laminate obtained in step (2) above to one side of a polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, product name "T-910 WM19", thickness: 50 μm) as a base material, a work handling sheet with a release sheet attached was obtained.

[0133] Here, the weight-average molecular weight (Mw) mentioned above is the weight-average molecular weight on a standard polystyrene basis, measured using gel permeation chromatography (GPC) under the following conditions (GPC measurement). <Measurement conditions> • Measuring device: Tosoh Corporation, HLC-8320 • GPC column (passes through in the following order): Manufactured by Tosoh Corporation TSK Gel Super H-H TSK gel superHM-H TSK Gel Super H2000 • Measurement solvent: tetrahydrofuran ·Measurement temperature: 40℃

[0134] [Examples 2-4] Work handling sheets were manufactured in the same manner as in Example 1, except that the type and content of additives, as well as the thickness of the interfacial ablation layer (adhesive layer), were changed as shown in Table 1.

[0135] [Example 5] 80 parts by mass of 2-ethylhexyl acrylate and 20 parts by mass of 2-hydroxyethyl acrylate were polymerized by solution polymerization to obtain a (meth)acrylic acid ester polymer. This (meth)acrylic acid ester polymer was reacted with 80 mol% of methacryloyloxyethyl isocyanate (MOI) relative to the 2-hydroxyethyl acrylate to obtain an acrylic polymer (active energy ray curable component) in which active energy ray curable groups were introduced into the side chains. The weight-average molecular weight (Mw) of this acrylic polymer was measured by the method described above and was found to be 1 million.

[0136] The above-mentioned acrylic polymer, in which active energy ray curable groups were introduced into the side chains, was mixed in a solvent with 100 parts by mass (based on solid content, the same applies hereafter), 2.5 parts by mass of trimethylolpropane-modified tolylene diisocyanate (manufactured by Tosoh Corporation, trade name "Coronate L") as a crosslinking agent, and 20 parts by mass of 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one (photopolymerization initiator, manufactured by IGM Resins, product name "Omnirad379") as an additive to obtain a coating solution for an adhesive composition.

[0137] A work handling sheet was manufactured in the same manner as in Example 1, except that the above-mentioned adhesive composition was used and the thickness of the interfacial ablation layer was changed as shown in Table 1.

[0138] [Examples 6-7 and Comparative Example 1] Work handling sheets were manufactured in the same manner as in Example 5, except that the crosslinking agent content and the types and contents of additives were changed as shown in Table 1.

[0139] [Comparative Example 2] A work handling sheet was manufactured in the same manner as in Example 1, except that no additives were used and the thickness of the interfacial ablation layer was changed as shown in Table 1.

[0140] [Test Example 1] (Measurement of Conversion Efficiency) (1) First UV irradiation (curing of the interfacial ablation layer) The release sheet was peeled off from the work handling sheets manufactured in the examples and comparative examples to expose the interface ablation layer. Then, ultraviolet (UV) light was irradiated onto the exposed surface of the interface ablation layer of the work handling sheet using an ultraviolet irradiation device (Lintec Corporation, product name "RAD-2000") equipped with a high-pressure mercury lamp as a light source (illuminance: 230 mW / cm²). 2 ,Light amount: 190mJ / cm 2 (Hereafter, this UV irradiation may be referred to as "the first UV irradiation.") This resulted in obtaining a work handling sheet "after UV irradiation."

[0141] In addition, in the work handling sheets of Examples 5-7 and Comparative Example 1, where the interfacial ablation layer is an adhesive layer composed of an active energy ray curable adhesive, the interfacial ablation layer was cured by the first ultraviolet irradiation described above.

[0142] (2) Second ultraviolet irradiation and measurement of heat quantity The work handling sheet that has undergone the first ultraviolet irradiation described above has an area of ​​0.126 cm². 2 The sample was cut in the manner described. The resulting sample was then placed in the measurement section of a differential scanning calorimeter (DSC) equipped with an ultraviolet irradiation device. Details of the ultraviolet irradiation device and differential scanning calorimeter used are as follows.

[0143] <Ultraviolet irradiation device> Product name "REX-250" manufactured by Asahi Spectroscopic Co., Ltd. Lamp: High-pressure mercury lamp 250W Interference filter: Bandpass filter LX0365 Output wavelength: 240nm~440nm

[0144] <Differential Scanning Calorimeter> Perkinelmer product name "DSC8500"

[0145] The ambient temperature of the differential scanning calorimeter was then adjusted to 30°C, and after the temperature and heat quantity stabilized, measurement of the sample was started. The measurement was performed in the following three steps. The measurement was carried out under a nitrogen gas atmosphere while supplying nitrogen gas to the measurement unit. In addition, ultraviolet light was irradiated so that it struck the side surface of the interface ablation layer perpendicularly. Step 1: Maintain the set ambient temperature of 30°C for 1 minute. Step 2: Set ambient temperature to 30°C and UV irradiance to 380mW / cm² 2 , Light intensity: 950mJ / cm 2 The device was irradiated for 0.3 minutes (hereafter, this UV irradiation may be referred to as the "second UV irradiation"). Step 3: Maintain the set ambient temperature of 30°C for 0.7 minutes.

[0146] Furthermore, as a reference, measurements were performed in the same manner as above, without placing a sample in the measurement unit.

[0147] Then, using the software attached to the differential scanning calorimeter, the measurement data obtained from the reference was subtracted from the measurement data obtained from the sample to obtain the calorific value data of the sample only (DSC curve with horizontal axis: time, vertical axis: heat generation per unit time). Next, the total heat generation of the work handling sheet after UV irradiation (mJ / cm²) was calculated as the integral value of the heat generation per unit time from the start to the end of the measurement in the said DSC curve. 2 The results were obtained. The results are shown in Table 2.

[0148] Furthermore, the work handling sheet after UV irradiation is replaced with the work handling sheet before UV irradiation (i.e., the work handling sheet that has not undergone the first UV irradiation described above), and the total heat generated by the work handling sheet before UV irradiation (mJ / cm²) is calculated in the same manner as above. 2 ) was obtained. The results are shown in Table 2.

[0149] Furthermore, by replacing the work handling sheet after UV irradiation with only the substrate used in the examples and comparative examples, the heat generated by the substrate (mJ / cm²) was measured in the same manner as above. 2 ) was obtained. The results are shown in Table 2.

[0150] (3) Calculation of conversion efficiency Next, using analysis software (Perkinelmer, product name "Pyris"), the conversion efficiency (%) of light energy to thermal energy due to the second UV irradiation was calculated based on the total heat generated by the work handling sheet before UV irradiation. The results are shown in Table 2 as the conversion efficiency (%) of the entire work handling sheet before UV irradiation. Note that this conversion efficiency is calculated based on the heat generated per unit area (mJ / cm²). 2 This is calculated by dividing () by the amount of ultraviolet light irradiated per unit area.

[0151] Furthermore, the amount of heat generated by the interfacial ablation layer was calculated by subtracting the amount of heat generated by the substrate alone from the total heat generated by the work handling sheet before UV irradiation. Based on this amount of heat generated by the interfacial ablation layer, the efficiency (%) of the conversion of light energy to thermal energy by the second UV irradiation was calculated in the same manner as above. The results are shown in Table 2 as the conversion efficiency (%) of the interfacial ablation layer before UV irradiation.

[0152] Furthermore, the amount of heat generated by the interfacial ablation layer was calculated by subtracting the amount of heat generated by the substrate alone from the total amount of heat generated by the work handling sheet after UV irradiation. Based on this amount of heat generated by the interfacial ablation layer, the conversion efficiency (%) of light energy to thermal energy by the second UV irradiation was calculated in the same manner as above. The results are shown in Table 2 as the conversion efficiency (%) of the interfacial ablation layer after UV irradiation.

[0153] [Test Example 2] (Measurement of UV absorbance) The release sheets were peeled off from the work handling sheets manufactured in the examples and comparative examples to expose the interface ablation layer. The ultraviolet absorbance of these work handling sheets was measured using a UV-Vis-Near-Infrared spectrophotometer (Shimadzu Corporation, product name "UV-3600") and its attached large sample chamber (Shimadzu Corporation, product name "MPC-3100"). This measurement was performed by using the integrating sphere built into the spectrophotometer to irradiate the surface with a wavelength of 355 nm light with a slit width of 20 nm, directed toward the surface facing the interface ablation layer. The results are shown in Table 2.

[0154] [Test Example 3] (Evaluation of suitability for laser lift-off) (1) Preparation of the chip on the work handling sheet (preparation process) An adhesive side of a dicing sheet (Lintec Corporation, product name "D-485H") was attached to one side of an 8-inch silicon wafer (#2000, thickness: 350 μm). Next, a dicing ring frame was attached to the periphery of the adhesive side of the dicing sheet (a position that does not overlap with the silicon wafer). Furthermore, the dicing sheet was cut to match the outer diameter of the ring frame. Then, using a dicing device (Disco Corporation, product name "DFD6362"), the silicon wafer was diced into chips measuring 300 μm x 300 μm. Finally, the dicing sheet was exposed to ultraviolet light (illuminance 230 mW / cm²) using an ultraviolet irradiation device (Lintec Corporation, product name "RAD2000"). 2 , light intensity 190mJ / cm 2 The adhesive layer of the dicing sheet was cured by irradiating it with a light source. This resulted in obtaining a laminate in which multiple chips were provided on the dicing sheet.

[0155] Next, the release sheet was peeled off from the work handling sheet manufactured in the examples and comparative examples, and the exposed surface was bonded to the surface of the laminate obtained as described above where the multiple chips were located. After that, the dicing sheet was peeled off from the multiple chips. This transferred the multiple chips from the dicing sheet to the work handling sheet, and a laminate was obtained in which the multiple chips were provided on the work handling sheet.

[0156] (2) Separation of chips by laser irradiation (separation process) In the laminate obtained in step (1) above, in which multiple chips are provided on a work handling sheet, laser light was irradiated onto the chips through the work handling sheet using a laser light irradiation device.

[0157] Here, all of the manufactured Examples 1-7 and Comparative Examples 1-2 were irradiated with laser light under Condition 1, which will be described later. In addition, for Comparative Example 2 only, (a sheet prepared separately from the sheet tested under Condition 1) laser light was also irradiated under Condition 2, which will be described later.

[0158] (2-1) Condition 1 Laser irradiation device (YAG third harmonic (wavelength 355 nm) with pulse width 20 ns and light intensity 700 mJ / cm²) 2 Using a work handling sheet, laser light was shone onto the chip. This irradiation was performed on a 270 μm × 270 μm area in the center of the chip. Other irradiation conditions were frequency: 30 kHz and irradiation dose: 50 μJ / shot. In addition, 100 chips (groups of 10 chips vertically × 10 chips horizontally) were selected from multiple chips and the irradiation was performed on them.

[0159] (2-2) Condition 2 A laser beam was irradiated onto the chip through a 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 beam spot in a circular motion. The diameter of the laser beam spot was set to 25 μm, and the inner diameter of the ring resulting from the irradiation trajectory was set to 65 μm. Other irradiation conditions were frequency: 40 kHz, scan speed: 500 mm / s, and irradiation dose: 50 μJ / shot. Irradiation was performed on 100 chips (groups of 10 chips vertically x 10 chips horizontally) selected from a group of chips.

[0160] Furthermore, condition 2 is a condition under which laser liftoff is more likely to occur compared to condition 1.

[0161] (3) Confirmation of blister and chip separation For the work handling sheets and tips subjected to the above irradiation, the presence or absence of blistering at the interface between the substrate and the interface ablation layer on the work handling sheet, and the presence or absence of detachment of the tip from the work handling sheet were checked for each condition, and the suitability for laser lift-off was evaluated based on the following criteria. The results are shown in Table 2. ◎...Blistering occurred at the location of all 100 chips, and all 100 chips detached. ○...The number of chips that developed blisters or detached was between 80 and 100. ×...The number of chips that developed blisters or detached was less than 80.

[0162] Further details regarding the abbreviations and other terms listed in Tables 1 and 2 are as follows: [UV absorber] Tinuvin477: Tris[2,4,6-[2-{4-(octyl-2-methylethanol)oxy-2-hydroxyphenyl}]-1,3,5-triazine (hydroxyphenyltriazine-based UV absorber, manufactured by BASF, product name "Tinuvin477") CYASORB UV-24: 2,2'-Dihydroxy-4-methoxybenzophenone (benzophenone-based UV absorber, manufactured by SOLVAY, product name "CYASORB UV-24") [Photopolymerization initiator] Omnirad379: 2-Dimethylamino-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one (manufactured by IGM Resins, product name "Omnirad379") IrugacureOXE02: Ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(0-acetyloxime) (manufactured by BASF, product name "IrugacureOXE02") Omnirad651: 2,2-dimethoxy-1,2-diphenylethane-1-one (manufactured by IGM Resins, product name "Omnirad651") Omnirad184: 1-Hydroxycyclohexylphenyl ketone (manufactured by IGM Resins, product name "Omnirad184")

[0163] [Table 1]

[0164] [Table 2]

[0165] As is clear from Table 1, the work handling sheets manufactured in the examples exhibited excellent laser lift-off suitability. In contrast, the work handling according to Comparative Example 2 performed poorly in terms of laser lift-off evaluation, even under condition 2, which is more prone to laser lift-off. [Industrial applicability]

[0166] The work handling sheet of the present invention can be suitably used in the manufacture of displays and the like that which are equipped with micro-light-emitting diodes as pixels. [Explanation of symbols]

[0167] 1…Work Handling Sheet 11,11'...Interfacial ablation layer 12...Base material 13…Reaction region 2,2'...Workpiece 3…Object 4…Activated energy rays 5… Laser light 6…Blister

Claims

1. Substrate and The substrate is laminated on one side, capable of holding a small workpiece, and undergoes interface ablation by irradiation with laser light. A work handling sheet equipped with, The substrate is a single-layer film made of resin, or a laminated film formed by stacking multiple such films. Ultraviolet light with a wavelength of 365 nm at a light intensity of 190 mJ / cm² ２ The work handling sheet, which has undergone the first ultraviolet irradiation using the above method, is further exposed to ultraviolet light with a wavelength of 365 nm at a rate of 950 mJ / cm². ２ When a second ultraviolet irradiation is performed with a light intensity of [specified], the conversion efficiency of the interface ablation layer in converting the ultraviolet light energy in the second ultraviolet irradiation into thermal energy is 60% or more. A work handling sheet characterized by the following features.

2. The work handling sheet according to claim 1, characterized in that the interfacial ablation layer is an adhesive layer composed of an active energy ray curable adhesive or a non-active energy ray curable adhesive.

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

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

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

6. A work handling sheet according to any one of claims 1 to 5, characterized in that it is used to selectively separate any work piece from the interface ablation layer from the interface ablation layer by curing the interface ablation layer whole or locally by irradiation with an active energy ray, and by causing localized interface ablation in the interface ablation layer by irradiation with a laser beam.

7. A preparation step of preparing a laminate in which a plurality of workpiece pieces are held on the surface on the interface ablation layer side of the work handling sheet according to any one of claims 1 to 6, A positioning step of arranging the laminate such that the side of the laminate facing the workpiece is facing an object capable of receiving the workpiece, A separation step is to irradiate the interface ablation layer in the laminate with laser light at a position where at least one of the workpiece pieces is attached, thereby causing interface ablation at the irradiated position in the interface ablation layer, thereby separating the workpiece piece located at the position where interface ablation has occurred from the work handling sheet, and placing the workpiece piece on the object. A method for handling small workpieces, characterized by comprising the following:

8. A preparation step of preparing a laminate in which a plurality of workpiece pieces are held on the surface on the interface ablation layer side of the work handling sheet according to any one of claims 1 to 6, A positioning step of arranging the laminate such that the side of the laminate facing the workpiece is facing an object capable of receiving the workpiece, A separation step is to irradiate the interface ablation layer in the laminate with laser light at a position where at least one of the workpiece pieces is attached, thereby causing interface ablation at the irradiated position in the interface ablation layer, thereby separating the workpiece piece located at the position where interface ablation has occurred from the work handling sheet, and placing the workpiece piece on the object. A device manufacturing method characterized by comprising the following:

9. Use of the work handling sheet according to any one of claims 1 to 6 for handling small pieces of work.

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