Workpiece processing sheet, workpiece processing method, device manufacturing method, and application of workpiece processing sheet

Abstract

The present application provides a workpiece processing sheet capable of processing even a fine workpiece piece. A workpiece processing sheet 1 provided with a base material 12 and an interface exfoliation layer 11 stacked on one face side of the base material 12, the interface exfoliation layer 11 capable of holding a workpiece piece while performing interface exfoliation by irradiation of laser light, the workpiece processing sheet 1 characterized in that: in the case where the workpiece processing sheet 1 subjected to first ultraviolet light irradiation of ultraviolet light of a wavelength of 365 nm with a light quantity of 190 mJ / cm 2 is further subjected to second ultraviolet light irradiation of ultraviolet light of a wavelength of 365 nm with a light quantity of 950 mJ / cm 2 , a conversion efficiency of the interface exfoliation layer 11 at the time of conversion of light energy of the ultraviolet light in the second ultraviolet light irradiation into heat energy is 60% or more.

Description

Technical Field

[0001] This invention relates to a workpiece processing sheet that can be used to process small workpiece pieces such as semiconductor components and semiconductor devices, a method for processing small workpiece pieces using the workpiece processing sheet and a method for manufacturing devices, and applications of the workpiece processing sheet, particularly to a workpiece processing sheet that can be used to process small workpiece pieces such as micro light-emitting diodes, power devices, and microelectromechanical systems (MEMS). Background Technology

[0002] In recent years, the development of displays using micro light-emitting diodes (micro LEDs) has been underway. In such displays, each pixel is composed of a micro LED, and the emission of each micro LED is independently controlled. The manufacturing process typically involves mounting micro LEDs, which are disposed on substrates such as sapphire or glass, onto a wiring substrate.

[0003] During the above installation, multiple miniature light-emitting diodes (LEDs) configured on the supply substrate need to be precisely placed at predetermined positions on the wiring substrate. At this time, it is necessary to selectively place predetermined miniature LEDs from among the multiple LEDs onto the wiring substrate, or to place multiple miniature LEDs simultaneously.

[0004] From the perspective of performing this installation effectively, the use of laser irradiation is being investigated. For example, a method is being investigated in which multiple miniature light-emitting diodes are held on a support through a predetermined layer, and then a laser is irradiated onto that layer, causing the layer to be etched at the irradiated location, thereby placing the miniature light-emitting diodes separated from the support (laser stripping) onto a wiring substrate (Patent Document 1). Due to the excellent directionality and focusing of lasers, the irradiation position is easily controlled, allowing for good selective placement.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 6546278 Summary of the Invention

[0008] The technical problem to be solved by the present invention

[0009] However, further miniaturization of micro LEDs and higher density mounting of micro LEDs are also underway. Correspondingly, efforts are being made to find a means to process small pieces of workpieces such as multiple micro LEDs more efficiently and effectively than conventional methods such as those in Patent Document 1.

[0010] The present invention was made in view of this practical situation, and its object is to provide a workpiece processing plate that can effectively process even tiny workpiece pieces.

[0011] Technical means to solve technical problems

[0012] To achieve the above objectives, firstly, the present invention provides a workpiece processing sheet comprising a substrate and an interface etching layer, wherein the interface etching layer is stacked on one side of the substrate, the interface etching layer is capable of holding the workpiece piece while simultaneously performing interface etching through laser irradiation, the workpiece processing sheet being characterized in that it has undergone interface etching at 190 mJ / cm 2 The workpiece is further subjected to a first ultraviolet irradiation with a wavelength of 365 nm, using 950 mJ / cm² light. 2 When the light intensity is irradiated by a second ultraviolet light with a wavelength of 365nm, the interface etched layer has a conversion efficiency of more than 60% when converting the light energy of the second ultraviolet light into heat energy (Invention 1).

[0013] The interface erosion layer of the workpiece processing piece of the above-mentioned invention (Invention 1) exhibits the above-mentioned conversion efficiency, and therefore can effectively perform interface erosion when irradiated with laser, thereby enabling the small workpiece piece to be well separated from the object.

[0014] In the above invention (Invention 1), it is preferred that the interface erosion layer is an adhesive layer composed of an active energy ray curable adhesive or an inactive energy ray curable adhesive (Invention 2).

[0015] In the above inventions (Inventions 1 and 2), it is preferred that the interface erosion layer contains at least one additive selected from ultraviolet absorbers and photopolymerization initiators (Invention 3).

[0016] In the above inventions (Inventions 1 to 3), it is preferable that the laser has a wavelength in the ultraviolet region (Invention 4).

[0017] In the above inventions (Inventions 1 to 4), it is preferable that when the interface erosion layer produces interface erosion, bubbles are formed at the location where the interface erosion occurs (Invention 5).

[0018] In the above inventions (Inventions 1-5), the workpiece processing sheet is preferably used for the following purpose: the interface erosion layer is solidified entirely or partially by irradiation with active energy rays, and interface erosion is locally generated in the interface erosion layer by irradiation with the laser, thereby selectively separating any one of the plurality of workpiece pieces held on the opposite side of the interface erosion layer from the interface erosion layer (Invention 6).

[0019] Second, the present invention provides a method for processing small workpiece pieces, characterized by comprising: a preparation step, wherein a laminate is prepared by holding a plurality of small workpiece pieces on the surface of the workpiece processing sheet (Inventions 1-6) on the side of the interface erosion layer; a configuration step, wherein the laminate is configured such that the surface of the laminate on the side of the small workpiece pieces faces an object capable of receiving the small workpiece pieces; and a separation step, wherein a laser is irradiated at least one position of the interface erosion layer in the laminate where the small workpiece pieces are attached, causing interface erosion at the irradiated position in the interface erosion layer, thereby separating the small workpiece pieces present at the position where the interface erosion occurs from the workpiece processing sheet, and placing the small workpiece pieces on the object (Invention 7).

[0020] Third, the present invention provides a device manufacturing method, characterized by comprising: a preparation step, wherein a laminate is prepared by holding a plurality of workpiece pieces on the surface of the workpiece processing sheet (Inventions 1-6) on the side of the interface erosion layer; a configuration step, wherein the laminate is configured such that the surface of the laminate on the side of the workpiece pieces faces an object capable of receiving the workpiece pieces; and a separation step, wherein a laser is irradiated at at least one position of the interface erosion layer in the laminate where the workpiece pieces are attached, causing interface erosion at the irradiated position in the interface erosion layer, thereby separating the workpiece pieces present at the position where the interface erosion occurs from the workpiece processing sheet, and placing the workpiece pieces on the object (Invention 8).

[0021] Fourth, the present invention provides the application of the workpiece processing sheet (Invention 1-6) in processing small workpiece pieces (Invention 9).

[0022] Invention Effects

[0023] Even for tiny pieces of workpiece, the workpiece processing sheet of the present invention can process them well. Attached Figure Description

[0024] Figure 1 This is a cross-sectional view of a workpiece processing sheet according to one embodiment of the present invention.

[0025] Figure 2 This is a cross-sectional view illustrating a method for processing a small piece of workpiece using a workpiece processing sheet according to one embodiment of the present invention, and a method for manufacturing a device.

[0026] Figure 3 A cross-sectional view illustrating the state of bubbles and reaction zones generated by laser irradiation. Detailed Implementation

[0027] The following describes the embodiments of the present invention.

[0028] Figure 1 A cross-sectional view of a workpiece processing sheet according to one embodiment is shown. Figure 1 The workpiece processing sheet 1 shown has a substrate 12 and an interface stripping layer 11 stacked on one side of the substrate 12.

[0029] In the workpiece processing sheet 1 of this embodiment, the interface etch layer 11 can hold the workpiece piece. That is, the workpiece processing sheet 1 of this embodiment can maintain the workpiece piece stacked on the surface opposite to the substrate 12 of the interface etch layer 11 in this state.

[0030] The specific method for maintaining the workpiece is not limited. As a preferred example, a method of maintaining the workpiece by making the interface etched layer 11 adhere to the interface etched layer is listed. In this case, as described later, the interface etched layer 11 preferably contains an adhesive as one of its components, that is, the interface etched layer 11 is preferably an adhesive layer.

[0031] Furthermore, the interface erosion layer 11 in this embodiment undergoes interface erosion due to laser irradiation. That is, the interface erosion layer 11 undergoes localized interface erosion in the area irradiated by the aforementioned laser. In addition, the aforementioned laser is not particularly limited as long as it can produce interface erosion, and can be a laser with a wavelength in any region of the ultraviolet, visible, and infrared regions, among which a laser with a wavelength in the ultraviolet region is preferred.

[0032] In this specification, interface erosion refers to the process where some components constituting the interface erosion layer 11 evaporate or volatilize due to the energy of the laser, and the resulting gas accumulates at the interface between the interface erosion layer 11 and the substrate 12, creating voids (bubbles). At this time, the shape of the interface erosion layer 11 changes due to the bubbles, and the workpiece piece peels off from the interface erosion layer 11 to separate the workpiece piece.

[0033] Furthermore, in the workpiece processing piece 1 of this embodiment, the workpiece was subjected to a process with a flow rate of 190 mJ / cm². 2 The workpiece treatment piece 1 was further subjected to first ultraviolet irradiation with ultraviolet light of wavelength 365nm at a concentration of 950mJ / cm. 2 When the light intensity is irradiated by a second ultraviolet light with a wavelength of 365nm, the conversion efficiency of the interface etched layer 11 in converting the light energy of the second ultraviolet light into heat energy is more than 60%.

[0034] The workpiece processing piece 1 of this embodiment can effectively generate interface erosion by satisfying the above-mentioned conversion efficiency, and can effectively separate the held workpiece pieces from the interface erosion layer 11. In particular, it can reduce the amount of laser irradiation required to achieve sufficient separation of the workpiece pieces and reduce the operating cost of the laser irradiation device. At the same time, it can easily and effectively separate only the target workpiece pieces, thereby improving accuracy, and can further prevent damage to the device and workpiece pieces caused by excessive laser irradiation.

[0035] 1. Interface erosion layer

[0036] As long as the workpiece can be maintained and the above-mentioned conversion efficiency can be met, there are no particular limitations on the specific structure and composition of the interface erosion layer 11 in this embodiment.

[0037] As described above, the interface erosion layer 11 is preferably an adhesive layer, and it is particularly preferred that the interface erosion layer 11 is an adhesive layer composed of an adhesive with active energy ray curing properties (active energy ray curing adhesive) or an adhesive without active energy ray curing properties (inactive energy ray curing adhesive).

[0038] Furthermore, from the perspective of easily achieving the aforementioned conversion efficiency, the interface etch layer 11 preferably contains at least one additive selected from ultraviolet absorbers and photopolymerization initiators.

[0039] (1) Active energy radiation curing adhesive

[0040] When the interface etch layer 11 is an adhesive layer composed of an adhesive that is cured by active energy rays, irradiation with active energy rays can reduce the adhesion between the workpiece processing sheet 1 and the workpiece piece in this embodiment. Therefore, the adhesion can be reduced by irradiating with active energy rays before or during the aforementioned interface etch, thereby reliably separating the workpiece piece from the workpiece processing sheet 1 in this embodiment. Furthermore, the amount of laser irradiation required to achieve sufficient separation of the workpiece piece can be further reduced. In addition, since irradiation with active energy rays in the workpiece processing sheet 1 of this embodiment leads to a decrease in the adhesion of the workpiece piece, the adhesion before irradiation with active energy rays can be set to a higher level. As a result, when transferring the workpiece piece from other sheets to the workpiece processing sheet 1 of this embodiment, it is possible to prevent the workpiece piece from remaining on the other sheets, thereby achieving good transfer.

[0041] The aforementioned active energy ray curable adhesive can be any of the following adhesives: acrylic adhesive, rubber adhesive, silicone adhesive, urethane adhesive, polyester adhesive, polyvinyl ether adhesive, etc. However, from the perspective of easily achieving the desired adhesive force, acrylic adhesive is preferred.

[0042] Furthermore, the active energy radiation-curable adhesive can have a polymer with active energy radiation curability as its main component, or it can have a mixture of an inactive energy radiation-curable polymer (a polymer without active energy radiation curability) and monomers and / or oligomers having at least one or more active energy radiation-curable groups as its main component. Alternatively, it can be a mixture of a polymer with active energy radiation curability and an inactive energy radiation-curable polymer, a mixture of a polymer with active energy radiation curability and monomers and / or oligomers having at least one or more active energy radiation-curable groups, or a mixture of all three.

[0043] First, the following explains the case where the active energy ray curable adhesive uses a polymer with active energy ray curability as the main component.

[0044] The polymer with active energy-curable properties is preferably a (meth)acrylate (copolymer) polymer (A) with an energy-curable functional group (active energy-curable group) introduced into its side chain (hereinafter sometimes also referred to as "active energy-curable polymer (A)"). This active energy-curable polymer (A) is preferably obtained by reacting an acrylic copolymer (a1) having a functional group monomer unit with a compound (a2) having an unsaturated group bonded to that functional group. Furthermore, in this specification, (meth)acrylate refers to both acrylate and methacrylate. Other similar terms are also used.

[0045] The acrylic copolymer (a1) preferably contains structural units derived from functionalized monomers and structural units derived from (meth)acrylate monomers or their derivatives.

[0046] The functionalized monomers used as structural units of acrylic copolymers (a1) are preferably monomers with polymerizable double bonds and functional groups such as hydroxyl, carboxyl, amino, substituted amino, and epoxy groups within the molecule.

[0047] Examples of hydroxyl-containing monomers include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxybutyl methacrylate, and 4-hydroxybutyl methacrylate. These hydroxyl-containing monomers can be used alone or in combination of two or more.

[0048] Examples of carboxyl-containing monomers include acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid, among other olefinic unsaturated carboxylic acids. These carboxyl-containing monomers can be used alone or in combination of two or more.

[0049] Examples of amino-containing or substituted amino monomers include aminoethyl (meth)acrylate and n-butylaminoethyl (meth)acrylate. These amino-containing or substituted amino monomers can be used alone or in combination of two or more.

[0050] As the (meth)acrylate monomer constituting the acrylic copolymer (a1), in addition to (meth)acrylate alkyl esters with alkyl carbon atoms of 1 to 20, monomers having an intramolecular alicyclic structure (monomers containing alicyclic structure) are preferably used.

[0051] Alkyl methacrylates are particularly preferred as alkyl methacrylates, with the alkyl group having 1 to 18 carbon atoms, such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, and 2-ethylhexyl methacrylate. These alkyl methacrylates can be used alone or in combination of two or more.

[0052] As alicyclic monomers, cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, adamantyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyl oxyethyl (meth)acrylate are preferred examples. These alicyclic monomers can be used alone or in combination of two or more.

[0053] The acrylic copolymer (a1) preferably contains the aforementioned structural units derived from the functionalized monomer at a proportion of 1% by mass or more, particularly preferably at a proportion of 5% by mass or more, and even more preferably at a proportion of 10% by mass or more. Furthermore, the acrylic copolymer (a1) preferably contains the aforementioned structural units derived from the functionalized monomer at a proportion of 35% by mass or less, particularly preferably at a proportion of 30% by mass or less, and even more preferably at a proportion of 25% by mass or less.

[0054] Furthermore, the acrylic copolymer (a1) preferably contains structural units derived from (meth)acrylate monomers or their derivatives in a proportion of 50% by mass or more, particularly preferably in a proportion of 60% by mass or more, and even more preferably in a proportion of 70% by mass or more. Additionally, the acrylic copolymer (a1) preferably contains structural units derived from (meth)acrylate monomers or their derivatives in a proportion of 99% by mass or less, particularly preferably in a proportion of 95% by mass or less, and even more preferably in a proportion of 90% by mass or less.

[0055] Acrylic copolymers (a1) can be obtained by copolymerizing the functionalized monomers described above with (meth)acrylate monomers or their derivatives using conventional methods. In addition to these monomers, they can also be copolymerized from dimethacrylamide, vinyl formate, vinyl acetate, styrene, etc.

[0056] By reacting the acrylic copolymer (a1) having a functional group monomer unit with a compound (a2) having an unsaturated group bonded to the functional group, an active energy ray-curable polymer (A) can be obtained.

[0057] The functional groups of the unsaturated group compound (a2) can be appropriately selected according to the type of functional groups of the functional group monomer units of the acrylic copolymer (a1). For example, when the functional group of the acrylic copolymer (a1) is hydroxyl, amino, or substituted amino, the functional group of the unsaturated group compound (a2) is preferably isocyanate or epoxy group. When the functional group of the acrylic copolymer (a1) is epoxy group, the functional group of the unsaturated group compound (a2) is preferably amino, carboxyl, or aziridinyl.

[0058] Furthermore, the above-mentioned compound (a2) containing unsaturated groups contains at least one energy-ray polymerizable carbon-carbon double bond in one molecule, preferably one to six energy-ray polymerizable carbon-carbon double bonds in one molecule, and more preferably one to four energy-ray polymerizable carbon-carbon double bonds in one molecule. Specific examples of such compounds containing unsaturated groups (a2) include 2-methacryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1,1-(bisacryloyloxymethyl)ethyl isocyanate; acryloyl monoisocyanate compounds obtained by reacting diisocyanate compounds or polyisocyanate compounds with hydroxyethyl (meth)acrylate; acryloyl monoisocyanate compounds obtained by reacting diisocyanate compounds or polyisocyanate compounds with polyol compounds 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.

[0059] Relative to the molar number of functionalized monomers in the aforementioned acrylic copolymer (a1), the aforementioned compound containing unsaturated groups (a2) is preferably used at a proportion of 50 mol% or more, particularly preferably at a proportion of 60 mol% or more, and even more preferably at a proportion of 70 mol% or more. Furthermore, relative to the molar number of functionalized monomers in the aforementioned acrylic copolymer (a1), the aforementioned compound containing unsaturated groups (a2) is preferably used at a proportion of 95 mol% or less, particularly preferably at a proportion of 93 mol% or less, and even more preferably at a proportion of 90 mol% or less.

[0060] In the reaction of an acrylic copolymer (a1) with a compound containing unsaturated groups (a2), the reaction temperature, pressure, solvent, time, presence or absence of a catalyst, and type of catalyst can be appropriately selected based on the combination of functional groups possessed by the acrylic copolymer (a1) and the compound containing unsaturated groups (a2). Thus, the functional groups present in the acrylic copolymer (a1) react with the functional groups in the compound containing unsaturated groups (a2), and the unsaturated groups are introduced into the side chains of the acrylic copolymer (a1), yielding an active energy radiation-curable polymer (A).

[0061] The weight-average molecular weight (Mw) of the thus obtained active energy radiation-curable polymer (A) is preferably 10,000 or more, particularly preferably 100,000 or more, and even more preferably 150,000 or more. Furthermore, this 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. Additionally, the weight-average molecular weight (Mw) in this specification is a converted value of standard polystyrene determined by gel permeation chromatography (GPC).

[0062] Even when the active energy ray-curable adhesive is mainly composed of a polymer with active energy ray curability, such as an active energy ray-curable polymer (A), the active energy ray-curable adhesive may further contain energy ray-curable monomers and / or oligomers (B).

[0063] As monomers and / or oligomers (B) that can be cured by active energy rays, for example, polyols and esters of (meth)acrylic acid can be used.

[0064] Monofunctional acrylates such as cyclohexyl methacrylate and isobornyl methacrylate (B) that can be cured by active energy rays include: 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 dimethyloltricyclodecane di(meth)acrylate; polyester oligo(meth)acrylates, polyurethane oligo(meth)acrylates, etc.

[0065] When an active energy radiation-curable polymer (A) is infused with an active energy radiation-curable monomer and / or oligomer (B), the content of the active energy radiation-curable monomer and / or oligomer (B) in the active energy radiation-curable adhesive is preferably greater than 0 parts by mass relative to 100 parts by mass of the active energy radiation-curable polymer (A), and particularly preferably 60 parts by mass or more. Furthermore, this content is preferably 250 parts by mass or less relative to 100 parts by mass of the active energy radiation-curable polymer (A), and particularly preferably 200 parts by mass or less.

[0066] Secondly, the following describes the case where the active energy ray-curable adhesive is mainly composed of a mixture of an inactive energy ray-curable polymer component and a monomer and / or oligomer having at least one active energy ray-curable group.

[0067] As a component of an inactive energy ray-curable polymer, for example, the same component as the acrylic copolymer (a1) described above can be used.

[0068] As monomers and / or oligomers having at least one active energy-curable group, for example, the same monomers and / or oligomers as component (B) described above can be selected. Regarding the blending ratio of the inactive energy-curable polymer component to the monomers and / or oligomers having at least one active energy-curable group, relative to 100 parts by mass of the inactive energy-curable polymer component, the monomers and / or oligomers having at least one active energy-curable group are preferably 1 part by mass or more, particularly preferably 60 parts by mass or more. Furthermore, regarding this blending ratio, relative to 100 parts by mass of the inactive energy-curable polymer component, the monomers and / or oligomers having at least one active energy-curable group are preferably 200 parts by mass or less, particularly preferably 160 parts by mass or less.

[0069] (2) Non-reactive energy radiation curing adhesive

[0070] When the interface etch layer 11 is an adhesive layer composed of an adhesive that is cured by non-active energy rays, 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 perspective of easily achieving the desired adhesive force, an acrylic adhesive is preferred.

[0071] Specific examples of acrylic adhesives that are non-reactive energy-curable adhesives include adhesives containing the aforementioned non-reactive energy-curable polymer components. The same components as the aforementioned acrylic copolymer (a1) can also be used as the non-reactive energy-curable polymer components. Furthermore, the non-reactive energy-curable adhesive does not contain the aforementioned polymers with active energy-curable properties, nor the aforementioned monomers and / or oligomers having at least one or more active energy-curable groups.

[0072] (3) Additives

[0073] As mentioned above, from the perspective of easily satisfying the above-mentioned conversion efficiency, it is preferable that the interface etch layer 11 of this embodiment contains at least one additive selected from ultraviolet absorber and photopolymerization initiator.

[0074] (3-1) Ultraviolet absorber

[0075] The type of ultraviolet absorber in this embodiment is not particularly limited. The ultraviolet absorber in this embodiment can be an organic compound or an inorganic compound, but from the perspective of easily generating good interfacial erosion, an organic compound is preferred.

[0076] When the ultraviolet absorber is an organic compound, preferred examples include: hydroxyphenyltriazine ultraviolet absorbers, benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, benzoate ultraviolet absorbers, benzoxazinone ultraviolet absorbers, phenyl salicylate ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, nickel complex salt ultraviolet absorbers, hydroquinone ultraviolet absorbers, salicylic acid ultraviolet absorbers, malonic acid ultraviolet absorbers, and oxalic acid ultraviolet absorbers. These ultraviolet absorbers can be used alone or in combination of two or more.

[0077] Among the above-mentioned ultraviolet absorbers, from the perspective of having good absorption at the third harmonic (355nm) of YAG and being able to easily generate good interfacial erosion, at least one of hydroxyphenyltriazine ultraviolet absorbers, benzophenone ultraviolet absorbers and benzotriazole ultraviolet absorbers is preferred, and hydroxyphenyltriazine ultraviolet absorbers are particularly preferred.

[0078] Examples of hydroxyphenyl triazine-based ultraviolet absorbers include: 2-[4-(octyl-2-methylacetate)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)]-1,3,5-triazine, 2-[4-(2-hydroxy-3-dodecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-(2-hydroxy-3-tetaneoxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis- ... These include hydroxyphenyl triazine ultraviolet absorbers such as 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-methylacetate)oxy-2-hydroxyphenyl}]-1,3,5-triazine. These hydroxyphenyl triazine ultraviolet absorbers can be used alone or in combination of two or more.

[0079] Preferably, at least one of the following is used: tris[2,4,6-[2-{4-(octyl-2-methylacetate)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-tetrateoxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine].

[0080] Furthermore, when the ultraviolet absorber is an organic compound, it is preferable that the ultraviolet absorber has one or more heterocyclic rings as a characteristic of its chemical structure. In this case, the number of heterocyclic rings is preferably four or less, and particularly preferably one.

[0081] Furthermore, as other chemical structural features, the ultraviolet absorber of this embodiment preferably has at least one of a carbon ring and a heterocycle, and all the carbon rings and heterocycles in the ultraviolet absorber are monocyclic.

[0082] As a further feature of the chemical structure, the ultraviolet absorber of 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.

[0083] Among the aforementioned features of the chemical structure, it is preferable that each heterocycle, other than carbon, comprises at least one element selected from nitrogen, oxygen, phosphorus, sulfur, silicon, and selenium, and particularly preferably at least one element selected from nitrogen, oxygen, phosphorus, and sulfur. Furthermore, the number of atoms constituting the ring structure of the heterocycle is not particularly limited, for example, it is 3 or more and 9 or less, and particularly preferably 5 or more and 6 or less. Specific examples of preferred heterocycles include triazine, benzotriazole, thiophene, pyrrole, imidazole, pyridine, and pyrazine.

[0084] Furthermore, among the aforementioned chemical structural features, preferred examples of aromatic rings include benzene, naphthalene, anthracene, biphenyl, and terphenyl.

[0085] As a specific example of an ultraviolet absorber having the aforementioned chemical structural characteristics, tris[2,4,6-[2-{4-(octyl-2-methylacetate)oxy-2-hydroxyphenyl}]-1,3,5-triazine can be cited.

[0086] In this embodiment, when the interface etched layer 11 contains an ultraviolet absorber, the content of the ultraviolet absorber in the interface etched 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. By making the content of the ultraviolet absorber 11 1% by mass or more, the interface etched layer 11 effectively absorbs laser light, thereby facilitating good interface etching. Furthermore, the content of the ultraviolet absorber in the interface etched 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. By making the content of the ultraviolet absorber 75% by mass or less, the viscosity of the material used to form the interface etched layer 11 becomes appropriate, making it easy to ensure good film formation.

[0087] Furthermore, when the interface etched layer 11 in this embodiment is formed from the adhesive composition described later, an ultraviolet absorber may also be incorporated into the adhesive composition. In this 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 making the amount of ultraviolet absorber incorporated at 1% by mass or more, the interface etched layer 11 effectively absorbs laser light, thereby facilitating good interface etching. Furthermore, the amount of ultraviolet absorber incorporated into the above-mentioned adhesive composition is preferably 75% by mass or less, particularly preferably 40% by mass or less, and even more preferably 20% by mass or less. By making the amount of ultraviolet absorber incorporated at 75% by mass or less, the resulting adhesive readily exhibits the desired adhesive strength.

[0088] (3-2) Photopolymerization initiator

[0089] The photopolymerization initiator in this embodiment is not particularly limited. When the interface erosion layer 11 is an adhesive layer composed of an active energy ray-curable adhesive, the interface erosion layer 11 preferably contains a photopolymerization initiator. In this case, effective interface erosion is easily achieved, and the interface erosion layer 11 is effectively cured.

[0090] As photopolymerization initiators, specific examples 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-diphenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinyl-propane-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholinyl-phenyl)butane-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-methylpropane ketone, 1-[9-ethyl-6-(2- [Methylbenzoyl]-9H-carbazole-3-yl]acetone 1-(O-acetyloxime), benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, oligomeric [2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone], 2-benzyl-2-(dimethylamino)-4'-morpholinophenylbutanone, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, etc. These photopolymerization initiators can be used alone or in combination of two or more.

[0091] Among the above-mentioned photopolymerization initiators, at least one of 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-phenyl)butane-1-one, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]acetophenone-1-(O-acetyl oxime), 2-benzyl-2-(dimethylamino)-4'-morpholinophenylbutanone, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and 2,2-dimethoxy-1,2-diphenylacetophenone is preferred.

[0092] In this embodiment, when the interface etched layer 11 contains a photopolymerization initiator, the content of the photopolymerization initiator in the interface etched 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. By making the content of the photopolymerization initiator 11 1% by mass or more, the interface etched layer 11 effectively absorbs the laser, thereby facilitating good interface etching. Furthermore, the content of the photopolymerization initiator in the interface etched 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. By making the content of the photopolymerization initiator 75% by mass or less, the viscosity of the material used to form the interface etched layer 11 becomes appropriate, making it easy to ensure good film formation.

[0093] Furthermore, when the interface etched layer 11 in this embodiment is formed from the adhesive composition described later, a photopolymerization initiator may also be incorporated into the adhesive composition. In this case, the amount of photopolymerization initiator 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 making the amount of photopolymerization initiator 1% by mass or more, the interface etched layer 11 effectively absorbs the laser, thereby facilitating good interface etched action. Furthermore, the amount of photopolymerization initiator incorporated into the above-mentioned adhesive composition is preferably 75% by mass or less, particularly preferably 40% by mass or less, and even more preferably 25% by mass or less. By making the amount of photopolymerization initiator 75% by mass or less, the resulting adhesive readily exhibits the desired adhesive strength.

[0094] (4) Other ingredients

[0095] Other components may be appropriately incorporated into the adhesive constituting the interface etched layer 11 of this embodiment. Examples of such other components include crosslinking agents, inactive energy ray-curable polymer components, or oligomer components.

[0096] From the perspective of easily adjusting the storage modulus of the interface etched layer 11 to the desired range, a crosslinking agent is preferred. As a crosslinking agent, a multifunctional compound having functional groups that are reactive with the functional groups of the active energy ray-curable polymer (A) or acrylic copolymer (a1) 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, and reactive phenolic resins.

[0097] The amount of crosslinking agent incorporated relative to 100 parts by weight of the main agent is preferably 0.001 parts by weight or more, particularly preferably 0.1 parts by weight or more, and even more preferably 0.2 parts by weight or more. Furthermore, the amount of crosslinking agent incorporated relative to 100 parts by weight of the main agent is preferably 20 parts by weight or less, particularly preferably 10 parts by weight or less, and even more preferably 5 parts by weight or less. Additionally, when the interface etched layer 11 is composed of an active energy ray-curable adhesive, the aforementioned "main agent" refers to the aforementioned active energy ray-curable polymer (A); when the interface etched layer 11 is composed of an inactive energy ray-curable adhesive, the aforementioned "main agent" refers to the aforementioned acrylic copolymer (a1).

[0098] Examples of non-reactive energy ray-curable polymer or oligomer components include polyacrylates, polyesters, polyurethanes, polycarbonates, and polyolefins, with polymers or oligomers having a weight-average molecular weight (Mw) of 30 million to 2.5 million being preferred. Incorporating this component can improve adhesion, peelability, bonding with other layers, and storage stability.

[0099] (5) Thickness of the interface erosion layer

[0100] In this embodiment, the thickness of the interface etched 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 etched layer 11 is preferably 100 μm or less, particularly preferably 50 μm or less, and even more preferably 40 μm or less. By keeping the thickness of the interface etched layer 11 within the above range, it is easy to balance the retention of the workpiece pieces on the interface etched layer 11 with the separation of the workpiece pieces based on interface etching.

[0101] 2. Substrate

[0102] The composition and physical properties of the substrate 12 in this embodiment are not particularly limited. From the perspective of easily enabling the workpiece processing sheet 1 to perform the desired function, the substrate 12 is preferably made of resin. When the substrate 12 is made of 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 copolymers such as ethylene-(meth)acrylate copolymer, ethylene-(meth)acrylate copolymer, and other ethylene-(meth)acrylate copolymers; polyvinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer; (meth)acrylate copolymers; polyurethane; polyimide; polystyrene; polycarbonate; fluoropolymers, etc. In addition, the resin constituting the substrate 12 may be a resin formed by crosslinking the above resins, or a modified resin such as an ionomer of the above resins. Furthermore, the substrate 12 can be a single-layer film formed from the aforementioned resin, or it can be a laminated film composed of multiple such films. In this laminated film, the materials constituting each layer can be of the same type or different types.

[0103] To improve the adhesion of the interface etched layer 11, the surface of the substrate 12 in this embodiment can be treated with a surface treatment based on oxidation, texturing, or a primer treatment. Examples of oxidation methods include corona discharge treatment, plasma discharge treatment, wet chromium oxidation treatment, flame treatment, hot air treatment, ozone treatment, and ultraviolet irradiation treatment. Examples of texturing methods include sandblasting and thermal spraying.

[0104] The substrate 12 in this embodiment may contain various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, and fillers. Furthermore, if the interface etch layer 11 contains a material that is cured by active energy rays, the substrate 12 preferably has transmittance to active energy rays.

[0105] The method of manufacturing the substrate 12 in this embodiment is not particularly limited as long as the substrate 12 is made of resin. For example, it can be manufactured by using melt extrusion methods such as T-die method and circular die method; calendering method; solution method such as dry method and wet method to form the resin into a sheet.

[0106] The thickness of the substrate 12 in this embodiment 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 substrate 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. By ensuring the thickness of the substrate 12 is within the above-mentioned range, the workpiece processing sheet 1 possesses a predetermined balance of rigidity and flexibility, facilitating efficient processing of small workpiece pieces.

[0107] 3. Peeling sheet

[0108] In the case where the interface etch layer 11 of this embodiment contains an adhesive as one of its components, before attaching the workpiece piece to the side of the interface etch layer 11 opposite to the substrate 12, a release sheet can be laminated on that side for the purpose of protecting that side.

[0109] The composition of the release sheet is arbitrary, and examples include release sheets after peeling plastic films using a release agent or the like. Specific examples of such plastic films include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, as well as polyolefin films such as polypropylene and polyethylene. As the release agent, silicone, fluorine, long-chain alkyl, etc., can be used; among these, inexpensive silicone agents that provide stable performance are preferred.

[0110] The thickness of the aforementioned stripping sheet is not particularly limited; for example, it can be above 20 μm and below 250 μm.

[0111] 4. Other structures

[0112] In the workpiece processing sheet 1 of this embodiment, an adhesive layer can be laminated on the side of the interface etch layer 11 opposite to the substrate 12. In this workpiece processing sheet, a workpiece is attached to the side of the adhesive layer opposite to the interface etch layer 11, and the workpiece and adhesive layer are cut together, thereby obtaining a small workpiece piece with a monolithized adhesive layer. The chip can be easily fixed to an object on which the small workpiece piece is mounted using the monolithized adhesive layer. As the material constituting the adhesive layer, materials containing thermoplastic resin and low molecular weight thermosetting adhesive components, or materials containing B-stage (semi-cured) thermosetting adhesive components, are preferably used.

[0113] Furthermore, in the workpiece processing sheet 1 of this embodiment, a protective film forming layer may also be laminated on the side of the interface etch layer 11 opposite to the substrate 12. In this workpiece processing sheet, a workpiece is attached to the side of the protective film forming layer opposite to the interface etch layer 11, and the workpiece and the protective film forming layer are cut together, thereby obtaining a small workpiece piece with a monolithized protective film forming layer laminated on it. Preferably, a workpiece with a circuit formed on one surface is used as the workpiece, in which case the protective film forming layer is typically laminated on the side opposite to the surface with the circuit formed. By curing the monolithized protective film forming layer at a predetermined time, a protective film with sufficient durability can be formed on the small workpiece piece. The protective film forming layer is preferably formed from an uncured curable adhesive.

[0114] 5. Physical properties of workpiece processing sheets

[0115] (1) Conversion efficiency

[0116] In the workpiece processing piece 1 of this embodiment, as described above, after processing at 190 mJ / cm 2 The workpiece treatment piece 1 was further subjected to first ultraviolet irradiation with ultraviolet light of wavelength 365nm at a concentration of 950mJ / cm. 2 When the interface etched layer 11 is irradiated with a second ultraviolet light source with a wavelength of 365 nm, the conversion efficiency (hereinafter sometimes referred to as "conversion efficiency after ultraviolet irradiation") of the interface etched layer 11 in converting the light energy of the second ultraviolet light into heat energy is 60% or more. This allows for effective interface etching and enables good separation of the held workpiece pieces from the interface etched layer 11. From the perspective of achieving better separation, the conversion efficiency is preferably 65% ​​or more, and particularly preferably 75% or more. Furthermore, the upper limit of the conversion efficiency is not particularly limited; for example, it can be 99% or less, particularly 97% or less, and further, 95% or less.

[0117] Furthermore, in the workpiece processing sheet 1 of this embodiment, at a temperature of 950 mJ / cm² (without the aforementioned first ultraviolet irradiation)... 2 When the light intensity is irradiated with ultraviolet light of wavelength 365 nm, the conversion efficiency (hereinafter sometimes referred to as "conversion efficiency before ultraviolet irradiation") of the interface etched layer 11 in converting the light energy of the ultraviolet light into heat energy is preferably 70% or more, particularly preferably 75% or more, and even more preferably 80% or more. Therefore, it is easy to adjust the conversion efficiency after ultraviolet irradiation to the above range. Furthermore, the upper limit of the conversion efficiency before ultraviolet irradiation is not particularly limited; for example, it can be 100% or less, particularly 97% or less, and even more preferably 95% or less.

[0118] Furthermore, in the workpiece processing sheet 1 of this embodiment, at a temperature of 950 mJ / cm² (without the aforementioned first ultraviolet irradiation)... 2 When the workpiece processing sheet irradiates ultraviolet light with a wavelength of 365 nm, the conversion efficiency (hereinafter sometimes referred to as "conversion efficiency of workpiece processing sheet 1") of converting the light energy of the ultraviolet light into heat energy is preferably 70% or more, particularly preferably 80% or more, and even more preferably 85% or more. This makes it easy to ensure that the conversion efficiency after ultraviolet irradiation meets the above range. Furthermore, the upper limit of the conversion efficiency of workpiece processing sheet 1 is not particularly limited; for example, it can be 99% or less, particularly 97% or less, and even more preferably 95% or less.

[0119] Furthermore, the detailed method for determining the conversion efficiency described above is as described in the experimental examples below.

[0120] (2) Heat generation

[0121] In the workpiece processing piece 1 of this embodiment, after processing at 190 mJ / cm 2 The workpiece treatment piece 1 was further subjected to first ultraviolet irradiation with ultraviolet light of wavelength 365nm at a concentration of 950mJ / cm. 2 Under the condition of irradiation with a second ultraviolet light of 365nm wavelength, the heat generated by the workpiece processing sheet 1 is preferably 500mJ / cm². 2 The above, especially preferred, is 600 mJ / cm. 2 The above is further optimized to 700 mJ / cm. 2 The above describes the process. This effectively generates interfacial erosion and allows the retained workpiece pieces to separate well from the eroded interfacial layer 11. Furthermore, the upper limit of the aforementioned heat generation is not particularly limited; for example, it can be 2000 mJ / cm². 2 The following, in particular, can be 1500mJ / cm 2 The following can be further expressed as 1000 mJ / cm 2 the following.

[0122] Furthermore, in the workpiece processing sheet 1 of this embodiment, at a temperature of 950 mJ / cm² (without the aforementioned first ultraviolet irradiation)... 2 When irradiated with ultraviolet light at a wavelength of 365 nm, the heat generated by the workpiece processing sheet 1 is preferably 600 mJ / cm². 2 The above, especially preferred, is 700 mJ / cm. 2 The above is further optimized to 800 mJ / cm. 2The above describes the process. This effectively generates interfacial erosion and allows the retained workpiece pieces to separate well from the eroded interfacial layer 11. Furthermore, the upper limit of the aforementioned heat generation is not particularly limited; for example, it can be 2000 mJ / cm². 2 The following, in particular, can be 1500mJ / cm 2 The following can be further expressed as 1000 mJ / cm 2 the following.

[0123] Furthermore, in the workpiece processing sheet 1 of this embodiment, the substrate 12 is treated only with 950 mJ / cm² (without the aforementioned first ultraviolet irradiation). 2 When irradiated with ultraviolet light at a wavelength of 365 nm, the heat generation of the substrate 12 is preferably 1 mJ / cm². 2 The above is particularly preferred, with 5mJ / cm². 2 The above is further optimized to 10 mJ / cm 2 The above is true. From the perspective of facilitating effective interface erosion, the substrate 12 preferably exhibits such heat generation. Furthermore, the upper limit of the aforementioned heat generation is not particularly limited; for example, it can be 100 mJ / cm³. 2 The following, in particular, can be 90 mJ / cm 2 The following can be further expressed as 80 mJ / cm 2 the following.

[0124] In addition, the detailed method for measuring calorific value described above is as described in the experimental examples below.

[0125] (3) Absorbance

[0126] The absorbance of the workpiece processing piece 1 to light with a wavelength of 355 nm in this embodiment is preferably 0.5 or more, more preferably 2.0 or more, particularly preferably 2.5 or more, and even more preferably 3.0 or more. By making the absorbance to light with a wavelength of 355 nm 0.5 or more, the amount of light reaching the ultraviolet region of the workpiece piece when irradiated with laser can be reduced, and the workpiece piece can be separated while effectively suppressing surface damage. In addition, the upper limit of the above absorbance is not particularly limited, for example, it can be 6.0 or less. Furthermore, the details of the above absorbance measurement method are described in the experimental examples described later.

[0127] 6. Manufacturing method of workpiece processing sheet

[0128] The manufacturing method of the workpiece processing sheet 1 in this embodiment is not particularly limited. For example, the interface etching layer 11 can be formed directly on the substrate 12, or the interface etching layer 11 can be formed on the process sheet and then transferred to the substrate 12.

[0129] When the interface etched layer 11 contains an adhesive as one of its constituent components, the interface etched layer 11 can be formed using known methods. For example, a coating liquid containing an adhesive composition for forming the interface etched layer 11, and further containing a solvent or dispersant as needed, is prepared. The coating liquid is then applied to one side of the substrate or the peelable side of the release liner (hereinafter sometimes referred to as the "release surface"). Next, the interface etched layer 11 can be formed by drying the resulting coating film.

[0130] The coating of the aforementioned coating liquid can be carried out using known methods, such as bar coating, blade coating, roller coating, squeegee coating, die coating, gravure coating, etc. Furthermore, the properties of the coating liquid are not particularly limited as long as it can be coated; it may contain components for forming the interface etched layer 11 as a solute, or it may contain components for forming the interface etched layer 11 as a dispersed phase. Moreover, when forming the interface etched layer 11 on the release sheet, the release sheet can be used as a process material for peeling off, or it can be used to protect the interface etched layer 11 until it adheres to the substrate.

[0131] When the adhesive composition used to form the interface etched layer 11 contains the aforementioned crosslinking agent, it is preferable to change the aforementioned drying conditions (temperature, time, etc.) or to additionally provide a heat treatment, thereby causing the polymer components in the coating film to undergo a crosslinking reaction with the crosslinking agent, forming a crosslinked structure within the interface etched layer 11 at the desired density. Furthermore, to ensure that the aforementioned crosslinking reaction proceeds sufficiently, after obtaining the workpiece treatment sheet 1, it can be cured by, for example, standing in an environment at 23°C and 50% relative humidity for several days.

[0132] 7. How to use the workpiece treatment plate

[0133] The workpiece processing sheet 1 of this embodiment can be used for processing small workpiece pieces. As described above, in the workpiece processing sheet 1 of this embodiment, since the interface etch layer 11 is effectively etched by laser irradiation, the small workpiece piece held on the interface etch layer 11 can be separated with high precision toward a predetermined position.

[0134] As an example of the method of using the workpiece processing piece 1 in this embodiment, a method of selectively separating any one of a plurality of workpiece pieces held on the opposite side of the substrate 12 of the interface etch layer 11 from the interface etch layer 11 by locally generated interface etch in the interface etch layer 11.

[0135] In the above-described method of use, the plurality of workpiece pieces held on the interface etch layer 11 can be obtained by individually processing a workpiece (as the material of the workpiece piece) held on the surface of the interface etch layer 11 opposite to the substrate 12. That is, the workpiece pieces can be obtained by cutting a workpiece on the interface etch layer 11. Alternatively, workpiece pieces formed independently of the workpiece processing sheet 1 of this embodiment can be placed on the interface etch layer 11.

[0136] Furthermore, in the case where the workpiece processing sheet 1 of this embodiment has the aforementioned adhesive layer and protective film forming layer, it is preferable to cut these layers and the workpiece on the interface etch layer 11. This allows for the preparation of small workpiece sheets with these monolithically stacked layers.

[0137] Although the shape and size of the workpiece piece in this embodiment are not particularly limited, the area of ​​the workpiece piece when viewed from above is preferably 10 μm. 2 The above, especially preferred, is 100μm. 2 That's all. Furthermore, the area of ​​the small workpiece piece when viewed from above is preferably 1 mm². 2 The following is particularly preferred: 0.25mm 2 Furthermore, regarding the size of the workpiece piece, when the workpiece piece is rectangular, the smallest side of the workpiece piece is preferably 2 μm or more, particularly preferably 5 μm or more, and even more preferably 10 μm or more. Moreover, the aforementioned smallest side is preferably 1 mm or less, particularly preferably 0.5 mm or less. Specific examples of rectangular workpiece piece sizes include 2 μm × 5 μm and 10 μm.

[0138] ×10μm, 0.5mm×0.5mm, 1mm×1mm, etc. Even for such tiny workpiece pieces, especially those that are difficult to separate from the sheet based on the upward movement of the needle, the workpiece processing sheet 1 of this embodiment can process them well. On the other hand, even for workpieces with an area exceeding 1mm², 2 Small pieces of workpiece (e.g., 1mm) 2 ~2000mm 2 The workpiece processing piece 1 of this embodiment can also process relatively large workpiece pieces with a thickness of 1 to 10,000 μm (e.g., 10 to 1,000 μm).

[0139] Examples of workpiece pieces include semiconductor components and semiconductor devices; more specifically, examples include miniature light-emitting diodes (LEDs), power devices, and microelectromechanical systems (MEMS). Among these, LEDs are particularly suitable as workpiece pieces, especially those selected from sub-millimeter LEDs and miniature LEDs. In recent years, research has been conducted on the development of devices with high-density configurations of sub-millimeter LEDs and miniature LEDs. In the manufacture of such devices, the workpiece processing piece 1 of this embodiment, capable of handling these LEDs with high precision, is highly suitable.

[0140] In the following text, as a specific example of the use of workpiece processing piece 1, based on Figure 2 The processing methods for small workpieces and the manufacturing methods for components are described. These methods include at least a preparation process ( Figure 2 (a) of, configuration process ( Figure 2 (b) and curing process ( Figure 2 (c) and separation process ( Figure 2 (d) and Figure 2 These four processes (e)

[0141] In the preparation process, such as Figure 2 As shown in (a), a stack of multiple workpiece pieces 2 is prepared to be held on the surface of the workpiece processing sheet 1 on the interface etch layer 11 side in this embodiment. This stack can be prepared by placing separately manufactured workpiece pieces 2 onto the workpiece processing sheet 1, or by individually cutting (i.e., dicing) the workpieces held on the surface of the interface etch layer 11 side. This cutting can be performed using known methods.

[0142] As described above, the shape and size of the workpiece piece 2 are not particularly limited, and the preferred size is also as described above. Specific examples of the workpiece piece 2, as mentioned above, include semiconductor components, semiconductor devices, etc., and in particular, light-emitting diodes such as sub-millimeter light-emitting diodes and miniature light-emitting diodes.

[0143] like Figure 2 As shown in (b), in the subsequent configuration process, the laminate is configured such that the surface of the workpiece piece 2 facing the object 3 that can accommodate the workpiece piece 2 is arranged. Although examples of the object 3 are appropriately determined according to the device to be manufactured, when the workpiece piece 2 is a light-emitting diode, specific examples of the object 3 can be listed as substrates, sheets, reels, etc., and wiring substrates with wiring are particularly suitable.

[0144] Then, in the curing process, such as Figure 2As shown in (c), the entire interface etched layer 11 in the laminate is solidified by irradiating it with active energy rays 4. Thus, the interface etched layer 11 becomes the solidified interface etched layer 11'. Furthermore, although Figure 2 (c) describes the case where the entire interface etched layer 11 is irradiated with active energy rays 4, but the irradiation can also be performed only on at least one location in the interface etched layer 11 where the workpiece piece 2 is attached, thereby causing the interface etched layer 11 to be locally solidified.

[0145] The irradiation by the aforementioned active energy ray 4 can be carried out using known methods, such as an ultraviolet irradiation device with a high-pressure mercury lamp or an ultraviolet LED as the light source, or a laser irradiation device used in the separation process described later.

[0146] Then, in the separation process, such as Figure 2 As shown in (d), at least one location of the cured interface etched layer 11' of the above-mentioned laminate, where the workpiece piece 2 is attached, is irradiated with laser 5. This irradiation can be performed simultaneously on multiple locations where the workpiece piece 2 is attached, or it can be performed sequentially on these locations. The irradiation conditions for laser 5 are not limited as long as interface etched material can be produced. Known devices can be used as the laser irradiation apparatus.

[0147] Furthermore, when the aforementioned laser irradiation device is used to simultaneously irradiate the active energy ray 4 in the curing process and the laser 5 in the separation process, both the curing and separation processes can be performed concurrently. That is, the irradiation of the laser 5 in the separation process can be combined with the irradiation of the active energy ray 4 in the curing process, thereby simultaneously performing localized curing and interface etching of the interface etched layer 11. In this case, the peak wavelength of the laser 5 used for irradiation is preferably 300 nm or more, particularly preferably 310 nm or more, and even more preferably 350 nm or more. Furthermore, the aforementioned peak wavelength is preferably 400 nm or less, particularly preferably 390 nm or less, and even more preferably 380 nm or less. By irradiating with a laser 5 having this wavelength, the curing and interface etching of the interface etched layer 11 can be easily and effectively performed.

[0148] On the other hand, such as Figure 2As shown, when the curing and separation processes are performed as independent processes, the peak wavelength of the active energy ray 4 emitted from the ultraviolet irradiation device (especially a device equipped with an ultraviolet LED as a light source, and a laser irradiation device) used in the curing process is preferably 300 nm or more, particularly preferably 310 nm or more, and even more preferably 320 nm or more. Furthermore, the aforementioned peak wavelength is preferably 400 nm or less, particularly preferably 390 nm or less, and even more preferably 380 nm or less. The peak wavelength of the laser 5 emitted from the laser irradiation device used in the separation process is preferably 300 nm or more, particularly preferably 310 nm or more, and even more preferably 320 nm or more. Furthermore, the aforementioned 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 curing and separation processes with active energy rays 4 and laser 5 having the peak wavelengths described above, respectively, the curing and interface etching of the interface etched layer 11 can be easily and effectively performed in each process.

[0149] like Figure 2 As shown in (e), by irradiation with the laser 5 described above, interface erosion can be generated at the irradiated location in the cured interface erosion layer 11'. Specifically, by irradiation with the laser 5, the components constituting the region near the substrate 12 in the cured interface erosion layer 11' evaporate or volatilize, forming a reaction region 13. Then, the gas generated by the evaporation or volatilization accumulates between the substrate 12 and the reaction region 13, forming bubbles 6. Due to the formation of these bubbles 6, the cured interface erosion layer 11' undergoes local deformation at the location of the workpiece piece 2', and the workpiece piece 2' separates from the cured interface erosion layer 11' by peeling off. In summary, the workpiece piece 2' located at the location where the interface erosion occurs can be placed on the object 3.

[0150] In addition, the reaction zone 13 and bubbles 6 generated by the irradiation of the laser 5 usually remain after the separation of the workpiece piece 2'. Figure 3 The diagram illustrates the separation of workpiece pieces 2 by sequential laser irradiation, specifically showing the states after separation (two on the left), during separation (middle), and before separation (two on the right). As shown, typically, the separated bubbles 6 are slightly shrunken compared to the bubbles during separation.

[0151] Based on the method described above, various devices can be manufactured by appropriately selecting the workpiece piece 2 and the object 3. For example, when using a light-emitting diode selected from sub-millimeter light-emitting diodes and micro light-emitting diodes as the workpiece piece 2, a light-emitting device having multiple such light-emitting diodes can be manufactured; more specifically, a display can be manufactured. In particular, a display having micro light-emitting diodes as pixels and a display having multiple sub-millimeter light-emitting diodes as backlights can be manufactured.

[0152] The embodiments described above are for the purpose of facilitating understanding of the present invention and are not intended to limit the present invention. Therefore, the essence of the elements disclosed in the above embodiments is that they also include all design changes or equivalents that fall within the scope of the present invention.

[0153] For example, other layers may be stacked between the interface etch layer 11 and the substrate 12 in the workpiece processing sheet 1 of this embodiment, or on the side of the substrate 12 opposite to the interface etch layer 11. An adhesive layer is a specific example of such other layer. In this case, the aforementioned separation process can be performed with the adhesive layer side attached to a support table (a transparent substrate such as a glass plate).

[0154] Example

[0155] The present invention will be further described in detail below through examples, etc., but the scope of the present invention is not limited by these examples, etc.

[0156] [Example 1]

[0157] (1) Preparation of adhesive composition

[0158] The (meth)acrylate polymer was obtained by solution polymerization of 80 parts by mass of 2-ethylhexyl acrylate and 20 parts by mass of 2-hydroxyethyl acrylate. The weight-average molecular weight (Mw) of this acrylic polymer was determined using the above method and was found to be 600,000.

[0159] A coating solution of an adhesive composition is obtained by mixing 100 parts by weight (solid composition conversion, the same below) of the above-obtained acrylic polymer, 0.94 parts by weight of trimethylolpropane-modified toluene diisocyanate (manufactured by TOSOH CORPORATION, trade name "Coronate L") as a crosslinking agent, and 10 parts by weight of tris[2,4,6-[2-{4-(octyl-2-methylacetate)oxy-2-hydroxyphenyl}]-1,3,5-triazine (hydroxyphenyl triazine UV absorber, manufactured by BASF, product name "Tinuvin 477") as an additive.

[0160] (2) Formation of the interface erosion layer (adhesive layer)

[0161] A coating solution of the adhesive composition obtained in step (1) was applied to the release surface of a release sheet (manufactured by LINTEC Corporation, product name "SP-PET38131") on one side of a polyethylene terephthalate film with an organosilicon release agent layer formed thereon. The resulting coating film was dried by heating. As a result, a laminate consisting of an interface etched layer with a thickness of 5 μm formed by drying the coating film and the release sheet was obtained.

[0162] (3) Fabrication of workpiece processing sheet

[0163] The surface of the interfacial stripping layer of the laminate obtained in step (2) is bonded to one side of the polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, product name "T-910WM19", thickness: 50μm) which serves as the substrate, thereby obtaining a workpiece processing sheet in a state with a release sheet attached.

[0164] The weight-average molecular weight (Mw) mentioned above is the weight-average molecular weight converted from standard polystyrene determined by gel permeation chromatography (GPC) under the following conditions (GPC determination).

[0165] <Measurement Conditions>

[0166] Measuring apparatus: Manufactured by TOSOH CORPORATION, HLC-8320

[0167] GPC column (passes through in the following order): manufactured by TOSOH CORPORATION

[0168] TSK gel super HH

[0169] TSK gel super HM-H

[0170] TSK gel super H2000

[0171] Determination solvent: Tetrahydrofuran

[0172] Measurement temperature: 40℃

[0173] [Examples 2-4]

[0174] As shown in Table 1, the type, content, and thickness of the interface etch layer (adhesive layer) of the additives were changed, but the workpiece treatment sheet was manufactured in the same manner as in Example 1.

[0175] [Example 5]

[0176] 80 parts by mass of 2-ethylhexyl acrylate and 20 parts by mass of 2-hydroxyethyl acrylate were polymerized by solution polymerization to obtain a (meth)acrylate polymer. This (meth)acrylate polymer was then reacted with methacryloyloxyethyl isocyanate (MOI) at 80 mol% relative to the 2-hydroxyethyl acrylate content to obtain an acrylic polymer (reactive energy radiation curable component) with active energy radiation curable groups incorporated into its side chains. The weight-average molecular weight (Mw) of this acrylic polymer was determined using the above method and found to be 1 million.

[0177] A coating solution of an adhesive composition is obtained by mixing 100 parts by weight (solid component conversion, the same below) of the above-obtained acrylic polymer with active energy ray curable groups introduced into the side chain, 2.5 parts by weight of trimethylolpropane-modified toluene diisocyanate (manufactured by TOSOH CORPORATION, trade name "Coronate L") as a crosslinking agent, and 20 parts by weight of 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholinyl-phenyl)butane-1-one (photopolymerization initiator, manufactured by IGM Resins, product name "Omnirad 379") as an additive.

[0178] Using the above-described adhesive composition, and varying the thickness of the interface etched layer as shown in Table 1, the workpiece processing sheet was manufactured in the same manner as in Example 1.

[0179] [Examples 6-7 and Comparative Example 1]

[0180] The content of the crosslinking agent, the type and content of the additives were changed as shown in Table 1. Otherwise, the workpiece treatment sheet was manufactured in the same manner as in Example 5.

[0181] [Comparative Example 2]

[0182] Without using additives, and with the thickness of the interface etched layer varied as shown in Table 1, the workpiece processing sheet was manufactured in the same manner as in Example 1.

[0183] [Experimental Example 1] (Determination of Conversion Efficiency)

[0184] (1) First ultraviolet irradiation (curing of the interface erosion layer)

[0185] The stripping sheet was peeled off from the workpiece processing sheet manufactured in the examples and comparative examples, exposing the interface etched layer. Then, ultraviolet (UV) light (illuminance: 230 mW / cm²) was irradiated onto the exposed surface of the interface etched layer in the workpiece processing sheet using an ultraviolet irradiation device (manufactured by LINTEC Corporation, product name "RAD-2000") equipped with a high-pressure mercury lamp as the light source.2 Light intensity: 190 mJ / cm 2 (In the following text, this ultraviolet irradiation is sometimes referred to as "first ultraviolet irradiation"). This results in a workpiece treated "after UV irradiation".

[0186] In addition, in the workpiece processing sheets of Examples 5 to 7 and Comparative Example 1, where the interface etched layer is an adhesive layer composed of an active energy ray curable adhesive, the interface etched layer is cured by the above-mentioned first ultraviolet irradiation.

[0187] (2) Measurement of the second ultraviolet radiation and heat

[0188] To make the area 0.126 cm² 2 The workpiece sheet that has undergone the first ultraviolet irradiation is cut in the manner described above. The resulting measurement sample is placed in the measurement section of a differential scanning calorimeter (DSC) equipped with an ultraviolet irradiation device. Details of the ultraviolet irradiation device and the differential scanning calorimeter used are described below.

[0189] <Ultraviolet Irradiation Device>

[0190] Asahi Spectra Co., Ltd. manufactures product named "REX-250".

[0191] Lamp: 250W high-pressure mercury lamp

[0192] Interference filter: Bandpass filter LX0365

[0193] Emission wavelength: 240nm~440nm

[0194] Differential Scanning Calorimeter

[0195] Perkinelmer manufactures the product named "DSC 8500".

[0196] Then, the atmosphere temperature of the differential scanning calorimeter was adjusted to 30°C. After the temperature and heat stabilized, the measurement of the sample was started. The measurement was performed according to the following three steps. In addition, nitrogen gas was supplied to the measurement unit while the measurement was carried out in a nitrogen atmosphere. Furthermore, ultraviolet light was irradiated so that it was perpendicular to the surface of the interface etched layer.

[0197] Step 1: Maintain the atmosphere at the set temperature of 30°C for 1 minute.

[0198] Step 2: At a set ambient temperature of 30℃ and an illuminance of 380mW / cm² 2 Light intensity: 950 mJ / cm 2Irradiate with ultraviolet light for 0.3 minutes (in the following text, this ultraviolet irradiation is sometimes referred to as "second ultraviolet irradiation").

[0199] Step 3: Maintain the atmosphere at the set temperature of 30°C for 0.7 minutes.

[0200] In addition, for reference, the measurement was performed in the same manner as described above when the sample for measurement was not placed in the empty measuring section.

[0201] Then, using the software accompanying 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 data of the sample itself (a DSC curve with time on the horizontal axis and heat generation per unit time on the vertical axis). Next, the integral value of the heat generation per unit time from the start to the end of the measurement was calculated in the DSC curve, and the overall calorific value (mJ / cm²) of the UV-irradiated workpiece was obtained in the form of this integral value. 2 ).

[0202] The results are shown in Table 2.

[0203] Furthermore, the workpiece treatment sheet after UV irradiation is replaced with the workpiece treatment sheet before UV irradiation (i.e., the workpiece treatment sheet that has not undergone the first ultraviolet irradiation described above), and the overall heat generation (mJ / cm²) of the workpiece treatment sheet before UV irradiation is obtained in the same manner as described above. 2 The results are also shown in Table 2.

[0204] In addition, the UV-irradiated workpiece was replaced with the substrate used in the examples and comparative examples, and the heat generation of the substrate (mJ / cm²) was obtained in the same manner as described above. 2 The results are also shown in Table 2.

[0205] (3) Calculation of conversion efficiency

[0206] Then, using analysis software (manufactured by Perkinelmer, product name "Pyris"), the conversion efficiency (%) of light energy to heat energy based on the overall heat generation of the workpiece before UV irradiation was calculated. The results are presented in Table 2 as the overall conversion efficiency (%) of the workpiece before UV irradiation. Additionally, the heat generation per unit area (mJ / cm²) was also calculated. 2 The conversion efficiency is calculated by dividing the amount of ultraviolet light irradiating a unit area by the amount of ultraviolet light irradiating that area.

[0207] Furthermore, the heat generated by the interface etched layer is calculated by subtracting the heat generated by the substrate alone from the total heat generated by the workpiece before UV irradiation. Then, based on this heat generated by the interface etched layer, the conversion efficiency (%) of light energy to heat energy based on the second ultraviolet irradiation is calculated in the same manner as above. The results are shown in Table 2 as the conversion efficiency (%) of the interface etched layer before UV irradiation.

[0208] In addition, the heat generated by the interface etched layer is calculated by subtracting the heat generated by the substrate alone from the total heat generated by the workpiece after UV irradiation. Then, based on the heat generated by the interface etched layer, the conversion efficiency (%) of light energy to heat energy based on the second ultraviolet irradiation is calculated in the same manner as above. The results are shown in Table 2 as the conversion efficiency (%) of the interface etched layer after UV irradiation.

[0209] [Experimental Example 2] (Determination of Ultraviolet Absorbance)

[0210] The stripping sheet was peeled off from the workpiece processing sheet manufactured in the examples and comparative examples, exposing the interface etched layer. For this workpiece processing sheet, the ultraviolet absorbance was measured using a UV-Vis-NIR spectrophotometer (manufactured by Shimadzu Corporation, product name "UV-3600") and an attached large sample chamber (manufactured by Shimadzu Corporation, product name "MPC-3100"). This measurement was performed by irradiating a surface with a wavelength of 355 nm towards the interface etched layer side with a slit width of 20 nm using an integrating sphere built into the spectrophotometer. The results are shown in Table 2.

[0211] [Experimental Example 3] (Evaluation of Laser Abrasion Suitability)

[0212] (1) Preparation of chips on the workpiece processing chip (preparation process)

[0213] The adhesive side of a dicing die (manufactured by LINTEC Corporation, product name "D-485H") is attached to one side of an 8-inch silicon wafer (#2000, thickness: 350μm). Next, a dicing ring frame is attached to the periphery of the adhesive side of the dicing die (the portion not overlapping with the silicon wafer). The dicing die is then cut according to the outer diameter of the ring frame. The silicon wafer is then diced into 300μm × 300μm chips using a dicing apparatus (manufactured by DISCO CORPORATION, product name "DFD6362"). Finally, the dicing die is irradiated with ultraviolet light (230mW / cm²) using an ultraviolet irradiation device (manufactured by LINTEC Corporation, product name "RAD2000"). 2The light intensity is 190 mJ / cm² 2 This process cures the adhesive layer of the dicing die. This results in a laminate with multiple chips disposed on the dicing die.

[0214] Next, the release liner is peeled off from the workpiece processing sheet manufactured in the embodiments and comparative examples, and the exposed surface is bonded to the surface of the laminate with multiple chips as described above. Then, the dicing liner is peeled off from the multiple chips. Thus, the multiple chips are transferred from the dicing liner to the workpiece processing sheet, resulting in a laminate with multiple chips disposed on the workpiece processing sheet.

[0215] (2) Chip separation based on laser irradiation (separation process)

[0216] For the stacked body with multiple chips on the workpiece processing sheet obtained in the above process (1), a laser irradiation device is used to irradiate the chips with laser through the workpiece processing sheet.

[0217] Here, Examples 1-7 and Comparative Examples 1-2 were irradiated with laser under Condition 1 described later. In addition, Comparative Example 2 (a sheet prepared separately from the sheet tested under Condition 1) was further irradiated with laser under Condition 2 described later.

[0218] (2-1) Condition 1

[0219] The laser irradiation device used was a YAG third harmonic laser (wavelength 355nm) with a pulse width of 20ns and a light intensity of 700mJ / cm. 2 A laser is used to irradiate the chip through the workpiece processing wafer. This irradiation is performed on a 270μm × 270μm area in the center of the chip. Other irradiation conditions are set as follows: frequency: 30kHz, irradiation dose: 50μJ / shot. Furthermore, 100 chips (a group of 10 chips vertically × 10 chips horizontally) are selected from multiple chips and irradiated.

[0220] (2-2) Condition 2

[0221] Using a laser irradiation device (manufactured by KEYENCE CORPORATION, product name "MD-U1000C"), the chip is irradiated with a laser through the workpiece. The laser spot is irradiated sequentially towards the center of the chip in a circular motion. The diameter of the laser spot is set to 25 μm, and the inner diameter of the resulting loop (the irradiation trajectory) is 65 μm. Other irradiation conditions are set as follows: frequency: 40 kHz, scanning speed: 500 mm / s, irradiation dose: 50 μJ / shot. Furthermore, 100 chips (a group of 10 chips x 10 chips) are selected from multiple chips and irradiated.

[0222] In addition, condition 2 is a condition that makes laser ablation easier to achieve compared to condition 1.

[0223] (3) Confirmation of bubble and chip separation

[0224] For the workpiece wafers and chips subjected to the above irradiation, it was determined whether bubbles were generated at the interface between the substrate and the interface etched layer in the workpiece wafer under each condition, and whether the chip detached from the workpiece wafer. The suitability of laser ablation was evaluated based on the following criteria. The results are shown in Table 2.

[0225] ◎… Bubbles were generated at all 100 chip locations, and all 100 chips detached.

[0226] ○…The number of chips that generate bubbles and detach is more than 80 but less than 100.

[0227] ×… The number of chips that generate bubbles and detach is less than 80.

[0228] In addition, the details of the abbreviations, etc., recorded in Tables 1 and 2 are as follows.

[0229] UV absorber

[0230] Tinuvin 477: Tris[2,4,6-[2-{4-(octyl-2-methylacetate)oxy-2-hydroxyphenyl}]-1,3,5-triazine (hydroxyphenyltriazine UV absorber, manufactured by BASF, product name "Tinuvin 477")

[0231] CYASORB UV-24: 2,2'-Dihydroxy-4-methoxybenzophenone (benzophenone-based ultraviolet absorber, manufactured by SOLVAY, product name "CYASORB UV-24")

[0232] [Photopolymerization initiator]

[0233] Omnirad 379: 2-Dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-phenyl)butane-1-one (manufactured by IGM Resins, product name "Omnirad 379")

[0234] Irgacure OXE02: 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]acetone 1-(O-acetyl oxime) (manufactured by BASF, product name "Irgacure OXE02")

[0235] Omnirad 651: 2,2-Dimethoxy-1,2-diphenylethyl ketone (manufactured by IGM Resins, product name "Omnirad 651")

[0236] Omnirad 184: 1-Hydroxy-cyclohexyl-phenyl-one (manufactured by IGM Resins, product name "Omnirad 184")

[0237]

[0238]

[0239] As shown in Table 1, the workpiece processing sheets manufactured in the examples exhibit excellent laser ablation suitability. Furthermore, even under condition 2, which makes laser ablation more likely, the laser ablation evaluation results for the workpiece processing sheets of Comparative Example 2 are poor.

[0240] Industrial applicability

[0241] The workpiece processing sheet of the present invention can be applied to the manufacture of displays and the like, which have miniature light-emitting diodes as pixels.

[0242] Explanation of reference numerals in the attached figures

[0243] 1: Workpiece processing sheet; 11, 11': Interface etch layer; 12: Substrate; 13: Reaction area; 2, 2': Small workpiece piece; 3: Object; 4: Active energy ray; 5: Laser; 6: Bubble.

Claims

1. A workpiece processing sheet, comprising: Substrate; and An interface etching layer, which is stacked on one side of the substrate, can hold the small workpiece piece while performing interface etching through laser irradiation. The interface erosion layer is a single-layer adhesive layer composed of an active energy ray-cured adhesive or an inactive energy ray-cured adhesive. The workpiece processing sheet is characterized in that... The interface erosion layer contains at least one additive selected from ultraviolet absorbers and photopolymerization initiators. The ultraviolet absorber is at least one of tris[2,4,6-[2-{4-(octyl-2-methylacetate)oxy-2-hydroxyphenyl}]-1,3,5-triazine and 2,2'-dihydroxy-4-methoxybenzophenone. The photopolymerization initiator is at least one selected from 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholinyl-phenyl)butane-1-one, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]acetophenone-1-(O-acetyloxime) and 2,2-dimethoxy-1,2-diphenylacetophenone. The content of the ultraviolet absorber or the photopolymerization initiator in the interface erosion layer is more than 5% by mass and less than 25% by mass. The test was conducted at 190 mJ / cm 2 The workpiece is further subjected to a first ultraviolet irradiation with a wavelength of 365 nm, using 950 mJ / cm² light. 2 When the light intensity is irradiated by a second ultraviolet light with a wavelength of 365nm, the conversion efficiency of the interface etched layer in converting the light energy of the second ultraviolet light into heat energy is above 60%.

2. The workpiece processing sheet according to claim 1, characterized in that, The substrate is a single-layer film formed of resin, or a laminated film composed of multiple such films.

3. The workpiece processing sheet according to claim 1, characterized in that, The laser has a wavelength in the ultraviolet region.

4. The workpiece processing sheet according to claim 1, characterized in that, When interfacial erosion occurs in the interfacial erosion layer, bubbles are formed at the location where the interfacial erosion occurs.

5. The workpiece processing sheet according to claim 1, characterized in that, The workpiece processing sheet is used for the following purposes: to cure the interface erosion layer as a whole or partially by irradiation with active energy rays, and to locally generate interface erosion in the interface erosion layer by irradiation with the laser, thereby selectively separating any one of a plurality of workpiece pieces held on the opposite side of the interface erosion layer from the interface erosion layer.

6. A method for processing small pieces of workpieces, characterized in that, have: The preparation process includes preparing a laminate formed by holding a plurality of small workpiece pieces on the surface of the workpiece processing sheet on the interface etch layer side as described in any one of claims 1 to 5. In the configuration process, the laminate is configured such that the surface of the laminate facing the workpiece piece faces the object capable of receiving the workpiece piece; and In the separation process, a laser is irradiated at least one location of the interface erosion layer in the laminate to which the workpiece piece is attached, causing interface erosion at the irradiated location in the interface erosion layer, thereby separating the workpiece piece at the location where the interface erosion occurs from the workpiece processing sheet, and placing the workpiece piece on the object.

7. A method for manufacturing a device, characterized in that, have: The preparation process includes preparing a laminate formed by holding a plurality of small workpiece pieces on the surface of the workpiece processing sheet on the interface etch layer side as described in any one of claims 1 to 5. The configuration process includes arranging the laminated body such that the surface of the laminated body facing the object capable of receiving the workpiece piece; and In the separation process, a laser is irradiated at least one location of the interface erosion layer in the laminate to which the workpiece piece is attached, causing interface erosion at the irradiated location in the interface erosion layer, thereby separating the workpiece piece at the location where the interface erosion occurs from the workpiece processing sheet, and placing the workpiece piece on the object.

8. The application of the workpiece processing sheet according to any one of claims 1 to 5 in processing small workpiece pieces.

Images