Workpiece processing sheet and device manufacturing method

Abstract

Provided is a workpiece processing sheet 1 including a base material 12, and an interfacial ablation layer 11 that is laminated on one side of the base material 12, can hold a workpiece chip, and generates interfacial ablation by irradiation of laser light. The interfacial ablation layer 11 contains a photosensitizer, and the absorbance of light at 365 nm of a solution in which the photosensitizer is dissolved in an organic solvent at a concentration of 10 ppm is 0.3 or greater. The workpiece processing sheet 1 can process workpiece chips of various sizes and thicknesses.

Description

Technical Field

[0001] This invention relates to a workpiece processing wafer that can be used to process small pieces of workpieces such as semiconductor components and semiconductor devices, and a device manufacturing method using the workpiece processing wafer. Background Technology

[0002] Semiconductor wafers such as silicon and gallium arsenide, as well as various packages, are manufactured in large-diameter form. After being cut into small component pieces (semiconductor chips) and then individually peeled off, they are transferred to the subsequent process, namely the mounting process. At this time, the semiconductor wafers and other workpieces are attached to semiconductor processing wafers with substrate and adhesive layers, and undergo back-side grinding, cutting, cleaning, drying, expansion, picking, and mounting processes.

[0003] In the aforementioned pick-up and mounting process, a suction nozzle is used to remove the semiconductor chips from the semiconductor processing wafer one by one and place them in designated positions. At this time, a push pin is also used to lift the semiconductor chips from the back of the semiconductor processing wafer, expanding the semiconductor processing wafer and thus spacing the semiconductor chips apart.

[0004] In recent years, the development of displays using micro LEDs has included research on using laser irradiation to mount each micro LED onto a substrate. For example, Patent Document 1 describes a method where multiple micro LEDs are held on a support via a defined layer, and then a laser is irradiated onto that layer, causing it to ablate at the irradiated location. This process allows the micro LEDs, separated from the support (laser lift-off), to be mounted onto a wiring substrate. Because lasers have excellent directivity and focusing, the irradiation position can be easily controlled, enabling selective mounting. Existing technical documents Patent documents

[0005] Patent Document 1: Japanese Patent No. 6546278 Summary of the Invention (a) Technical problems to be solved

[0006] However, the further miniaturization of micro LEDs and the higher density packaging of micro LEDs are also advancing. In order to cope with this situation, there is a need for a method that can process a large number of micro LEDs, such as tiny workpieces, more efficiently than the existing method in Patent Document 1.

[0007] However, the semiconductor chips obtained by dicing semiconductor wafers are typically larger than miniature light-emitting diodes. Therefore, even if the laser lift-off method described above is used to replace the picking and mounting of semiconductor wafers, the problem of not being able to effectively separate the semiconductor chips still exists.

[0008] The present invention was implemented in view of the above-mentioned actual situation, and its object is to provide a workpiece processing sheet that can effectively process small workpiece pieces of various sizes and thicknesses, and a device manufacturing method using the workpiece processing sheet. (II) Technical Solution

[0009] To achieve the above objectives, in a first aspect, the present invention provides a workpiece processing sheet having a substrate and an interface ablation layer, wherein the interface ablation layer is stacked on one side of the substrate and is capable of holding the workpiece piece and undergoing interface ablation by irradiation with a laser. The workpiece processing sheet is characterized in that the interface ablation layer contains a photosensitizer, and the absorbance of light at a wavelength of 365 nm measured for a solution of the photosensitizer dissolved in an organic solvent at a concentration of 10 ppm is 0.3 or more (Invention 1).

[0010] By including a photosensitizer in the interface ablation layer that meets the above-mentioned absorbance conditions, the workpiece processing sheet of the above invention (Invention 1) can effectively undergo interface ablation when irradiated with a laser, thereby enabling the small workpiece piece to be well separated from the object. Therefore, regardless of the size or thickness of the processed workpiece piece, good laser ablation can be performed.

[0011] In the above invention (Invention 1), the photosensitizer is preferably a compound having a heterocyclic ring (Invention 2).

[0012] In the above inventions (Inventions 1 and 2), the photosensitizer is preferably at least one of coumarin-based photosensitizers and pyrazoline-based photosensitizers (Invention 3).

[0013] In the above inventions (Inventions 1 to 3), it is preferred that the content of the photosensitizer in the interface ablation layer is 0.1% or more and 10% or less (Invention 4).

[0014] In the above inventions (Inventions 1-4), it is preferred that the content of the ultraviolet absorber in the interface ablation layer is 10% or less (Invention 5).

[0015] In the above inventions (Inventions 1 to 5), it is preferred that the laser has a wavelength in the ultraviolet region (Invention 6).

[0016] In the above inventions (Inventions 1 to 6), it is preferable that when the interface ablation layer undergoes interface ablation, bubbles are formed at the location where the interface ablation occurs (Invention 7).

[0017] In the above inventions (Inventions 1-7), the workpiece processing piece is preferably used to: selectively separate any one of the plurality of workpiece pieces held on the surface of the interface ablation layer opposite to the substrate from the interface ablation layer by utilizing the interface ablation that occurs locally in the interface ablation layer (Invention 8).

[0018] In the above inventions (Inventions 1-7), the interface ablation layer preferably contains an active energy ray curing component (Invention 9).

[0019] In the above invention (Invention 9), the workpiece processing sheet is preferably used to: cure the interface ablation layer as a whole or in part by irradiation with active energy rays, and to locally ablate the interface ablation layer by the irradiation laser, thereby selectively separating any workpiece piece among a plurality of workpiece pieces held on the surface of the interface ablation layer opposite to the substrate from the interface ablation layer (Invention 10).

[0020] In a second aspect, the present invention provides a device manufacturing method, characterized by comprising: a preparation step for preparing a laminate formed by holding a plurality of workpiece pieces on the surface of the interface ablation layer side of the workpiece processing sheet (Inventions 1-8); a configuration step for arranging the laminate with the workpiece piece side of the laminate facing an object that can accommodate the workpiece pieces; and a separation step (Invention 11) for irradiating a laser at a position in the laminate where at least one workpiece piece is attached to the interface ablation layer, causing interface ablation at the irradiated position of the interface ablation layer, thereby separating the workpiece piece present at the position where interface ablation occurs from the workpiece processing sheet, and placing the workpiece piece on the object.

[0021] In a third aspect, the present invention provides a device manufacturing method, characterized by comprising: a preparation step for preparing a laminate consisting of a plurality of workpiece pieces held on the surface of the interface ablation layer side of the workpiece processing sheet (Invention 9, 10); a configuration step for arranging the laminate with the workpiece piece side of the laminate facing an object that can accommodate the workpiece pieces; a curing step for irradiating the entire interface ablation layer in the laminate, or the location of the interface ablation layer in the laminate where at least one workpiece piece is attached, with an active energy ray, thereby curing the interface ablation layer entirely or partially; and a separation step (Invention 12) for irradiating the location of the interface ablation layer in the laminate where at least one workpiece piece is attached with a laser, causing interface ablation of the irradiated location of the interface ablation layer, thereby separating the workpiece piece present at the location where interface ablation occurred from the workpiece processing sheet and placing the workpiece piece on the object.

[0022] In the above invention (Invention 12), it is preferable to perform the separation process (Invention 13) after the curing process is completed.

[0023] In the above inventions (Inventions 12, 13), it is preferable to implement the separation process by irradiating the laser with the active energy rays in the curing process, thereby simultaneously implementing local curing of the interface ablation layer and interface ablation (Invention 14). (III) Beneficial Effects

[0024] The workpiece processing sheet of the present invention can effectively process small workpiece pieces of various sizes and thicknesses, and the device manufacturing method of the present invention can manufacture devices with excellent performance. Attached Figure Description

[0025] Figure 1 This is a cross-sectional view of a workpiece processing sheet according to one embodiment of the present invention. Figure 2 A cross-sectional view illustrating a device manufacturing method using a workpiece processing sheet according to one embodiment of the present invention. Figure 3 A cross-sectional view illustrating another example of a device manufacturing method using a workpiece processing sheet according to one embodiment of the present invention. Figure 4 A cross-sectional view illustrating the state of the bubbling and reaction zone caused by laser irradiation. Detailed Implementation

[0026] The following describes the embodiments of the present invention. Figure 1 The figure shows a cross-sectional view of a workpiece processing sheet according to one embodiment. Figure 1 The workpiece processing sheet 1 shown includes: a substrate 12 and an interface ablation layer 11 stacked on one side of the substrate 12.

[0027] In the workpiece processing sheet 1 of this embodiment, the interface ablation layer 11 is able to retain the workpiece piece. That is, the workpiece processing sheet 1 of this embodiment can retain the workpiece piece on the surface opposite to the substrate 12 that is stacked on the interface ablation layer 11 in its original state.

[0028] The specific form of retention described above is not limited, but as a preferred example, the interface ablation layer 11 retains the workpiece piece by exerting its adhesiveness. In this case, the interface ablation layer 11 preferably contains an adhesive as one of its components, as described below, i.e., it is preferably an adhesive layer.

[0029] Furthermore, in this embodiment, the interface ablation layer 11 undergoes interface ablation by irradiating a laser. That is, the interface ablation layer 11 will locally undergo interface ablation in the area irradiated by the laser. In addition, the laser is not particularly limited as long as it can cause interface ablation, and can be any laser with a wavelength in the ultraviolet region, the visible light region, and the infrared region, wherein a laser with a wavelength in the ultraviolet region is preferred.

[0030] In this specification, interface ablation refers to the evaporation or volatilization of some components constituting the interface ablation layer 11 due to the energy of the laser, resulting in gas remaining at the interface between the interface ablation layer 11 and the substrate 12, thus creating voids (bubbles). In this case, the interface ablation layer 11 deforms due to the bubbles, and the workpiece piece peels off from the interface ablation layer 11, causing the workpiece piece to separate.

[0031] Furthermore, the interface ablation layer 11 in this embodiment contains a photosensitizer. Moreover, regarding this photosensitizer, the absorbance of light at a wavelength of 365 nm, measured with respect to a solution of the photosensitizer dissolved in an organic solvent at a concentration of 10 ppm, is 0.3 or higher.

[0032] In this embodiment, the interface ablation layer 11, due to the presence of a photosensitizer exhibiting the aforementioned absorbance, has increased energy absorption efficiency from the laser. In conventional laser ablation, the laser used has a dominant peak around 365 nm; by using the aforementioned photosensitizer, energy efficiency can be significantly improved compared to using other photosensitizers. As a result, interface ablation can occur effectively, allowing for good separation of the held workpiece piece from the interface ablation layer 11. In particular, considering the size and thickness of the workpiece piece to be separated, as well as the laser irradiation method, the workpiece processing sheet 1 of this embodiment can effectively separate the workpiece piece, even under conditions where separation is difficult with existing workpiece processing sheets.

[0033] Furthermore, in addition to the aforementioned photosensitizer, the interface ablation layer 11 in this embodiment preferably contains an active energy ray curing component.

[0034] Since the interface ablation layer 11 in this embodiment contains a component that can be cured by active energy rays, the adhesion between the workpiece processing sheet and the workpiece piece can be reduced by irradiation with active energy rays. Therefore, by reducing adhesion before or during the aforementioned interface ablation, the workpiece piece can be reliably separated from the workpiece processing sheet of this embodiment by irradiation with active energy rays. Furthermore, the amount of laser irradiation required to fully separate the workpiece piece can be reduced. Furthermore, since the adhesion to the workpiece piece decreases due to irradiation with active energy rays, the adhesion before irradiation with active energy rays can be set to a slightly higher level. Therefore, when transferring the workpiece piece from other sheets to the workpiece processing sheet of this embodiment, the workpiece piece can be prevented from remaining on those other sheets, and a good transfer can be performed.

[0035] 1. Interface ablation layer Regarding the specific structure and composition of the interface ablation layer 11 in this embodiment, there are no particular limitations as long as it can maintain the small piece of workpiece, has the property of interface ablation due to laser irradiation, and contains a photosensitizer that meets the absorbance conditions.

[0036] In this embodiment, the interface ablation layer 11 is preferably an adhesive layer as described above. The adhesive constituting this adhesive layer can 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 strength, an acrylic adhesive is preferred. In this case, when the interface ablation layer 11 is composed of an acrylic adhesive, it is preferably formed from an adhesive composition containing the aforementioned photosensitizer and acrylic polymer.

[0037] (1) Acrylic polymers Regarding the aforementioned acrylic polymers, there are no particular limitations as long as the interface ablation layer 11 (adhesive layer) can exhibit the specified adhesive properties. For example, the acrylic polymer preferably comprises structural units derived from functionalized monomers, structural units derived from (meth)acrylate monomers, or derivatives thereof. Furthermore, in this specification, (meth)acrylate refers to both acrylates and methacrylates. The same applies to other similar terms.

[0038] The aforementioned functionalized monomers are preferably monomers that have polymerizable double bonds, hydroxyl, carboxyl, amino, substituted amino, epoxy, and other functional groups within the molecule.

[0039] 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. Two or more of these hydroxyl-containing monomers can be used alone or in combination.

[0040] Examples of carboxyl-containing monomers include acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citric acid, among other olefinic unsaturated carboxylic acids. These carboxyl-containing monomers can be used alone or in combination of two or more.

[0041] Examples of amino-containing or substituted amino monomers include ethyl amino(meth)acrylate and ethyl n-butylamino(meth)acrylate. These amino-containing or substituted amino monomers can be used alone or in combination of two or more.

[0042] As the above-mentioned (meth)acrylate monomers, in addition to (meth)acrylate alkyl esters with 1 to 20 carbon atoms in the alkyl group, monomers having an intramolecular alicyclic structure (monomers containing an alicyclic structure) are preferred.

[0043] Alkyl methacrylates, particularly those with alkyl groups having 1 to 18 carbon atoms, are preferred, for example, 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.

[0044] As monomers containing an alicyclic structure, cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, adamantyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate are preferred examples. These alicyclic monomers can be used individually or in combination of two or more.

[0045] The acrylic polymer preferably contains structural units derived from the aforementioned functionalized monomers at a rate of 1% or more by mass, particularly preferably 5% or more by mass, and even more preferably 10% or more by mass. Furthermore, the acrylic polymer preferably contains structural units derived from the aforementioned functionalized monomers at a rate of 35% or less by mass, particularly preferably 30% or less by mass, and even more preferably 25% or less by mass.

[0046] Furthermore, the acrylic polymer preferably contains structural units derived from (meth)acrylate monomers or their derivatives in a proportion of 50% or more by mass, particularly preferably 60% or more by mass, and even more preferably 70% or more by mass. Additionally, the acrylic polymer preferably contains structural units derived from (meth)acrylate monomers or their derivatives in a proportion of 99% or less by mass, particularly preferably 95% or less by mass, and even more preferably 90% or less by mass.

[0047] Acrylic polymers can be obtained by copolymerizing the above-mentioned functionalized monomers with (meth)acrylate monomers or their derivatives using conventional methods. However, in addition to these monomers, dimethacrylamide, vinyl formate, vinyl acetate, styrene, etc. can also be copolymerized.

[0048] The weight-average molecular weight (Mw) of the acrylic polymer obtained by the above method 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 1.5 million or less, particularly preferably 1.25 million or less, and even more preferably 1 million or less. Additionally, the weight-average molecular weight (Mw) in this specification is a value converted from standard polystyrene determined by gel permeation chromatography (GPC).

[0049] (2) Active energy ray curing components As mentioned above, the interface ablation layer 11 in this embodiment preferably contains, in addition to the aforementioned photosensitizer, an active energy ray curable component. There are no particular limitations on the active energy ray curable component, as long as it can be cured by irradiation with active energy rays. In the case where the interface ablation layer 11 in this embodiment contains an active energy ray curable component, the interface ablation layer 11 is preferably formed from an adhesive composition containing the active energy ray curable component and the aforementioned photosensitizer.

[0050] Furthermore, the active energy ray curable component can use a polymer with active energy ray curability as the main component, or it can use a mixture of an inactive energy ray curable polymer (a polymer without active energy ray curability) and monomers and / or oligomers having at least one active energy ray curable group as the main component. Alternatively, it can be a mixture of a polymer with active energy ray curability and an inactive energy ray curable polymer, a mixture of a polymer with active energy ray curability and monomers and / or oligomers having at least one active energy ray curable group, or a mixture of all three.

[0051] First, the following explains the case where the active energy ray curable component uses a polymer with active energy ray curable properties as the main component.

[0052] The polymer with active energy-curable properties is preferably a (meth)acrylate (co)polymer (A) with an energy-curable functional group (active energy-curable group) introduced into its side chain (hereinafter, sometimes 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 having a functional group bonded to it.

[0053] Furthermore, the active energy ray-curable polymer (A) is the same as the acrylic polymer described in item (1) above, and can also exhibit the specified adhesive properties. Therefore, when forming the interfacial ablation layer 11 by using an adhesive composition containing the active energy ray-curable polymer (A), the adhesive composition may not contain the acrylic polymer described in item (1) above.

[0054] The acrylic copolymer (a1) preferably comprises structural units derived from functionalized monomers and structural units derived from (meth)acrylate monomers or their derivatives. The functionalized monomers and (meth)acrylate monomers used here may be the same monomers used as structural units in the acrylic polymer described in item (1) above. Furthermore, the content of these monomers in the acrylic copolymer (a1) is preferably the same as that in the acrylic polymer described in item (1) above.

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

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

[0057] The functional groups of the compound (a2) containing unsaturated groups can be appropriately selected based on the type of functional groups of the monomer units containing functional groups in the acrylic copolymer (a1). For example, if the functional group of the acrylic copolymer (a1) is hydroxyl, amino, or substituted amino, then isocyanate or epoxy groups are preferred as functional groups in the compound (a2) containing unsaturated groups. If the functional group of the acrylic copolymer (a1) is epoxy, then amino, carboxyl, or aziridinium groups are preferred as functional groups in the compound (a2) containing unsaturated groups.

[0058] Furthermore, the aforementioned compound (a2) containing unsaturated groups contains at least one, preferably one to six, and more preferably one to four energy-ray polymerizable carbon-carbon double bonds per molecule. Specific examples of such compounds (a2) containing unsaturated groups include, for instance, 2-methacrylate isocyanate, α,α-dimethyl-m-isopropenylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1,1-(bisacryloyloxymethyl)ethyl isocyanate; acryloyl monoisocyanate compounds obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth)acrylate; acryloyl monoisocyanate compounds obtained by reacting a diisocyanate compound or a polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate; glycidyl (meth)acrylate; (meth)acrylic acid, 2-(1-aziridinyl)(meth)acrylate ethyl ester, 2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline, etc.

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

[0060] In the reaction between an acrylic copolymer (a1) and a compound (a2) containing unsaturated groups, the reaction temperature, pressure, solvent, time, whether to add a catalyst, and the type of catalyst can be appropriately selected based on the combination of functional groups possessed by the acrylic copolymer (a1) and the compound (a2) containing unsaturated groups. Thus, the functional groups present in the acrylic copolymer (a1) react with the functional groups in the compound (a2) containing unsaturated groups, thereby introducing unsaturated groups 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 active energy radiation-curable polymer (A) obtained by the above method is preferably 10,000 or more, particularly preferably 100,000 or more, and even more preferably 150,000 or more. Furthermore, the weight-average molecular weight (Mw) is preferably 1,500,000 or less, particularly preferably 1,250,000 or less, and even more preferably 1,000,000 or less.

[0062] Even when the active energy ray curable component is a polymer with active energy ray curable properties (A) as the main component, the active energy ray curable component 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] As monomers and / or oligomers (B) that can be cured by this active energy ray, examples include monofunctional acrylates such as cyclohexyl methacrylate and isobornyl methacrylate, polyfunctional acrylates such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, polyester oligo(meth)acrylate, and polyurethane oligo(meth)acrylate.

[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] Next, the following describes the case where the active energy ray curable component uses 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 as the main component.

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

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

[0069] (3) Photosensitizer The photosensitizer in this embodiment is not particularly limited as long as it meets the following condition: the absorbance of light at a wavelength of 365 nm measured for a solution of the photosensitizer dissolved in an organic solvent at a concentration of 10 ppm is 0.3 or higher.

[0070] From the perspective of more easily improving the efficiency of self-laser energy reception, the absorbance of the photosensitizer in this embodiment is more preferably 0.4 or more, particularly preferably 0.5 or more, and even more preferably 0.8 or more. Furthermore, the organic solvent used for measuring the absorbance can be selected according to each photosensitizer, taking into account factors such as the solubility of the photosensitizer. Different organic solvents have very little effect on the measured absorbance. Regarding the above absorbance, the photosensitizer is dissolved in an organic solvent to prepare a 10 ppm solution, and the absorption spectrum at wavelengths of 200-800 nm is measured using a spectrophotometer, with the absorbance read at 365 nm.

[0071] From the perspective of easily satisfying the above-mentioned absorbance conditions, the photosensitizer in this embodiment is preferably a compound containing heterocyclic rings. The compound may contain one or more heterocyclic rings. Furthermore, the compound may also contain both heterocyclic rings and carbocyclic rings.

[0072] The aforementioned heterocycle preferably has at least one element selected from nitrogen, oxygen, phosphorus, sulfur, silicon, and selenium, and particularly preferably has at least one element selected from nitrogen, oxygen, phosphorus, and sulfur as an element other than carbon constituting its heterocycle.

[0073] Furthermore, the number of atoms constituting the ring structure of the above-mentioned heterocycle is not particularly limited, for example, it is 3 or more and 9 or less, and is particularly preferred to be 5 or more and 6 or less.

[0074] From the perspective of easily achieving the above-mentioned absorbance and thus easily achieving good interface ablation, the photosensitizer in this embodiment is preferably at least one of a coumarin-based photosensitizer having a coumarin skeleton and a pyrazoline-based photosensitizer having a pyrazoline skeleton.

[0075] The content of the photosensitizer in the interface ablation layer 11 is preferably 0.1% or more, particularly preferably 0.5% or more, and even more preferably 0.9% or more. Furthermore, this content is preferably 10% or less, particularly preferably 8% or less, and even more preferably 6% or less. By keeping the photosensitizer content within these ranges, efficient interface ablation can easily occur.

[0076] (4) Crosslinking agent The adhesive composition preferably contains a crosslinking agent. By using a crosslinking agent, the storage modulus of the interfacial ablation layer 11 can be easily adjusted to a desired range. As a crosslinking agent, a multifunctional compound that is reactive with the functional groups of acrylic polymers or active energy radiation-curable polymers (A) 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.

[0077] The amount of crosslinking agent in the adhesive composition is preferably 0.001 parts by mass or more, particularly preferably 0.1 parts by mass or more, and even more preferably 0.2 parts by mass or more, relative to 100 parts by mass of the acrylic polymer or the active energy radiation-curable polymer (A). Furthermore, the amount of crosslinking agent is preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, relative to 100 parts by mass of the acrylic polymer or the active energy radiation-curable polymer (A).

[0078] (5) Photopolymerization initiator In this embodiment, when the interface ablation layer 11 contains a component that can be cured by active energy rays, the adhesive composition preferably contains a photopolymerization initiator. This photopolymerization initiator is not particularly limited. By including a photopolymerization initiator in the interface ablation layer 11 in this embodiment, especially when ultraviolet light is used as the active energy ray, the polymerization and curing time and light irradiation amount of the interface ablation layer 11 can be reduced, while the interface ablation layer 11 can be effectively cured.

[0079] Specific examples of photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-diethoxy-1,2-diphenylethane-1-one, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, and 2-methyl-1-[4-(methylthiophene)] 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propanoyl)-benzyl]phenyl}-2-methyl-propanoyl-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-phenyl)butan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-morpholino-1-propan-1- ...hydroxy-1-{4-[4-[4-(2-hydroxyethoxy)-1-propan-1-one]-2-methyl-propanoyl-1-one, 2-hydroxy-1-{4-[4-[4-(2-hydroxyethoxy)-1-propan-1-one]-2-methyl-propanoyl-1-one, 2-hydroxy-1-{4-[4-[4-(2-hydroxyethoxy)-1-propan-1-one]-2-methyl-propanoyl-1-one, 2-hydroxy-1-{4-[4-[4-(2-hydroxy-2-methyl-propanoyl)-benzyl]-2-methyl-propanoyl-1-one, 2-hydroxy-1-{4-[4-[4-(2-hydroxy-2-methyl-propanoyl)-benzyl]-2-methyl-propanoyl-1-one, 2-hydroxy-1-{4-[4-[4-[4-(2-hydroxy-2-methyl-propanoyl)-benzyl]-2-methyl-propanoyl-1-one, 2-hydroxy-1-{4-[4-[4-[4-[4-[4 ]-2-Hydroxy-methylacetone, ethyl ketone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(0-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 acetal, acetophenone dimethyl acetal, 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.

[0080] Among the above-mentioned photopolymerization initiators, at least one of 1-hydroxycyclohexylphenyl ketone and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methyl-1-propanone is preferred.

[0081] The content of the photopolymerization initiator in the adhesive composition is preferably 0.1 parts by mass or more, particularly preferably 0.3 parts by mass or more, and even more preferably 0.5 parts by mass or more, relative to 100 parts by mass of the active energy ray curable component. Furthermore, the content of the above-mentioned active energy ray curable component relative to 100 parts by mass is preferably 20 parts by mass or less, particularly preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less. By keeping the content of the photopolymerization initiator within the above range, the interfacial ablation layer 11 can be easily and effectively cured.

[0082] (6) Other ingredients The interface ablation layer 11 may also contain other components besides those mentioned above. Examples of such other components include ultraviolet absorbers. By including an ultraviolet absorber in the interface ablation layer 11, it is sometimes expected that the efficiency of the interface ablation layer 11 in receiving laser energy will increase. However, depending on the type and amount of photosensitizer, sometimes good interface ablation may occur more easily when the interface ablation layer 11 does not contain an ultraviolet absorber or when its amount is extremely small. Therefore, even when using an ultraviolet absorber, the content of the ultraviolet absorber in the interface ablation layer 11 is preferably less than 10%, particularly preferably less than 5%, and even more preferably less than 1%. Furthermore, when the interface ablation layer 11 contains an ultraviolet absorber, its content is preferably 0.1% or more.

[0083] 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 facilitating good interfacial ablation, an organic compound is preferred.

[0084] When the ultraviolet absorber is an organic compound, preferred examples include hydroxyphenyl triazine-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, benzoic acid ester-based ultraviolet absorbers, benzoxazinone-based ultraviolet absorbers, phenyl salicylate-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, nickel complex salt-based ultraviolet absorbers, hydroquinone-based ultraviolet absorbers, salicylic acid-based ultraviolet absorbers, malonate-based ultraviolet absorbers, and oxalic acid-based ultraviolet absorbers. These organic compounds can be used alone or in combination of two or more.

[0085] Among the aforementioned ultraviolet absorbers, from the perspective of having good absorption of the third harmonic (355nm) of YAG and being able to easily undergo good interfacial ablation, it is preferable to use at least one of the following: hydroxyphenyl triazine ultraviolet absorbers, benzophenone ultraviolet absorbers, and benzotriazole ultraviolet absorbers, with hydroxyphenyl triazine ultraviolet absorbers being particularly preferred.

[0086] (7) Thickness of the interface ablation layer In this embodiment, the thickness of the interface ablation layer 11 is preferably 3 μm or more, particularly preferably 20 μm or more, and even more preferably 25 μm or more. Furthermore, the thickness of the interface ablation layer 11 is preferably 100 μm or less, particularly preferably 50 μm or less, and even more preferably 40 μm or less. By keeping the thickness of the interface ablation layer 11 within the above range, it is easy to balance the retention of the workpiece piece on the interface ablation layer 11 with the separation of the workpiece piece achieved by interface ablation.

[0087] 2. Substrate The composition and 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)acrylic acid copolymer, ethylene-(meth)acrylic acid methyl copolymer, and other ethylene-(meth)acrylic acid copolymers; polyvinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer; (meth)acrylic acid copolymers; polyurethane; polyimide; polystyrene; polycarbonate; fluoropolymers, etc. In addition, the resin constituting the substrate 12 may also be a resin formed by crosslinking the above-mentioned resins, or a modified resin such as an ionic copolymer of the above-mentioned resins. Furthermore, the substrate 12 can be a single-layer film formed from the aforementioned resin, or it can be a laminated film formed by stacking multiple layers of the aforementioned film. In this laminated film, the materials constituting each layer can be the same or different.

[0088] To improve the adhesion of the ablation layer 11 to the interface, the surface of the substrate 12 in this embodiment can be subjected to surface treatment or primer treatment based on oxidation, texturing, or other methods. 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 solvent spraying.

[0089] The substrate 12 in this embodiment may also contain various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, and fillers. Furthermore, when the interface ablation layer 11 contains a material cured by active energy rays, it is preferable that the substrate 12 is transmissive to active energy rays.

[0090] The manufacturing method of the substrate 12 in this embodiment is not particularly limited as long as it is a method of manufacturing the substrate 12 from resin. For example, it can be manufactured by the following methods: melt extrusion method such as T-die method or circular die method; calendering method; solution method such as dry method or wet method, etc., to form the resin into a sheet.

[0091] In this embodiment, the thickness of the substrate 12 is preferably 10 μm or more, particularly preferably 30 μm or more, and even more preferably 50 μm or more. Furthermore, the thickness of the 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 keeping the thickness of the substrate 12 within the above range, the workpiece processing sheet 1 achieves a predetermined balance between rigidity and flexibility, facilitating the proper processing of small workpiece pieces.

[0092] 3. Peeling sheet In this embodiment, when the interface ablation layer 11 contains an adhesive as one of its components, a release liner may be laminated on the surface of the interface ablation layer 11 opposite to the substrate 12 before the surface is attached to the workpiece piece for the purpose of protecting the surface.

[0093] The composition of the release sheet is arbitrary; examples include release sheets obtained by peeling a plastic film 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, and polyolefin films such as polypropylene and polyethylene. As the release agent, silicone-based, fluorine-based, and long-chain alkyl-based agents can be used; among these, silicone-based agents, which are inexpensive and provide stable performance, are preferred.

[0094] There are no particular limitations on the thickness of the aforementioned release sheet; for example, it can be above 20 μm and below 250 μm.

[0095] 4. Other components In the workpiece processing sheet 1 of this embodiment, an adhesive layer can be laminated on the surface of the interface ablation layer 11 opposite to the substrate 12. By attaching the sheet to the surface of the adhesive layer opposite to the interface ablation layer 11 and cutting the adhesive layer and the workpiece together, a small workpiece piece with a laminated adhesive layer can be obtained. The chip can be easily fixed to the object on which the small workpiece piece is to be mounted by the laminated adhesive layer. As the material constituting the adhesive layer, it is preferable to use a material containing a thermoplastic resin and a low molecular weight thermosetting adhesive component, or a material containing a B-stage (semi-cured) thermosetting adhesive component, etc.

[0096] Furthermore, in the workpiece processing sheet 1 of this embodiment, a protective film forming layer may also be laminated on the surface of the interface ablation layer 11 opposite to the substrate 12. By attaching a workpiece to such a sheet on the surface of the protective film forming layer opposite to the interface ablation layer 11, and cutting the protective film forming layer together with the workpiece, a small workpiece piece with a laminated, individually formed protective film forming layer can be obtained. Preferably, a workpiece with a circuit formed on one side is used as the workpiece; in this case, the protective film forming layer is typically laminated on the surface opposite to the surface where the circuit is formed. By curing the individually formed protective film forming layer at a predetermined time point, 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.

[0097] 5. Manufacturing method of workpiece processing sheet The manufacturing method of the workpiece processing sheet 1 in this embodiment is not particularly limited. For example, the interface ablation layer 11 can be formed directly on the substrate 12, or the interface ablation layer 11 can be formed on the process sheet and then transferred to the substrate 12.

[0098] When the interface ablation layer 11 contains an adhesive as one of its constituent components, the interface ablation layer 11 can be formed by known methods. For example, a coating liquid containing an adhesive composition for forming the interface ablation layer 11 and a solvent or dispersion medium as desired 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"). The resulting coating is then dried, thereby forming the interface ablation layer 11.

[0099] The coating of the aforementioned coating liquid can be carried out by 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; sometimes the components used to form the interface ablation layer 11 are contained as solutes, and sometimes they are contained as dispersion media. In addition, when the interface ablation layer 11 is formed on a release sheet, the release sheet can be used as a process material for peeling, or the interface ablation layer 11 can be protected until it is adhered to the substrate.

[0100] When the adhesive composition used to form the interface ablation layer 11 contains the aforementioned crosslinking agent, it is preferable to change the aforementioned drying conditions (temperature, time, etc.) or to perform a heat treatment to allow the polymer components in the coating to undergo a crosslinking reaction with the crosslinking agent, thereby forming a crosslinked structure within the interface ablation layer 11 at a desired density. Furthermore, to ensure the crosslinking reaction is fully carried out, after the workpiece processing sheet 1 is completed, it can be cured, for example, by standing it for several days at 23°C and 50% relative humidity.

[0101] 6. How to use the workpiece treatment plate The workpiece processing piece 1 of this embodiment is suitable for processing small workpiece pieces. As mentioned above, for the workpiece processing piece 1 of this embodiment, since the interface ablation layer 11 can be effectively ablated by irradiation with a laser, the small workpiece piece held on the interface ablation layer 11 can be separated from the workpiece piece at a specified position with high precision.

[0102] As an example of the method of using the workpiece processing piece 1 in this embodiment, a method of selectively separating any workpiece piece among a plurality of workpiece pieces held on the surface of the interface ablation layer 11 opposite to the substrate 12 from the interface ablation layer 11 by utilizing the interface ablation that occurs locally in the interface ablation layer 11.

[0103] In the above-described method of use, the plurality of workpiece pieces held on the interface ablation layer 11 can be obtained by individually processing the workpiece (the material that becomes the workpiece piece) held on the surface opposite to the substrate 12 of the interface ablation layer 11 on that surface. That is, the workpiece pieces can be obtained by cutting the workpiece on the interface ablation layer 11. Alternatively, regarding the workpiece pieces, industrial pieces formed independently of the workpiece processing piece 1 of this embodiment can also be placed on the interface ablation layer 11.

[0104] Furthermore, when the workpiece processing sheet 1 in 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 ablation layer 11. This allows for the acquisition of a small workpiece sheet formed by stacking these layers.

[0105] The shape and size of the workpiece piece in this embodiment are not particularly limited. However, regarding size, when the workpiece piece is rectangular, the smallest side is preferably 0.3 mm or more, particularly preferably 1 mm or more, and even more preferably 1.5 mm or more. Furthermore, the smallest side is preferably 50 mm or less, particularly preferably 20 mm or less, and even more preferably 10 mm or less. On the other hand, it can also effectively handle areas smaller than 0.09 mm². 2 Small pieces of workpiece (e.g., 10μm) 2 ~0.09mm 2 This embodiment of the workpiece processing sheet can effectively process small industrial pieces of various sizes and thicknesses, ranging from 1 to 10,000 μm (e.g., 5 to 500 μm).

[0106] Examples of workpiece pieces include semiconductor components and semiconductor devices; more specifically, examples include miniature light-emitting diodes (LEDs), power devices, and MEMS (Micro Electro Mechanical Systems). Among these, LEDs are particularly suitable for use with miniature LEDs and micro-LEDs. In recent years, devices with high-density configurations of miniature LEDs and micro-LEDs have been researched and developed. For the manufacture of such devices, the workpiece processing piece 1 of this embodiment, which can process these LEDs with high precision, is very suitable.

[0107] The following is a specific usage example of workpiece processing piece 1, based on Figure 2 The device manufacturing method is described. This device manufacturing method includes at least a preparation step (…). Figure 2 (a) of, configuration process ( Figure 2 (b) and separation process ( Figure 2 The three processes are (c) and (d).

[0108] In the preparation process, such as Figure 2 As shown in (a), a laminate consisting of multiple workpiece pieces 2 held on the surface of the workpiece processing sheet 1 on the interface ablation layer 11 side is prepared according to this embodiment. This laminate 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 ablation layer 11 side. This cutting can be performed using known methods.

[0109] The shape and size of the workpiece piece 2 are as described above, without any particular limitation, and the preferred size is also as described above. Specific examples of the workpiece piece 2, as described above, include semiconductor components, semiconductor devices, and in particular, miniature light-emitting diodes and micro-light-emitting diodes.

[0110] In the subsequent configuration process, such as Figure 2 As shown in (b), the above-mentioned laminate is arranged such that the surface of the workpiece piece 2 faces the object 3 that can accommodate the workpiece piece 2. Examples of the object 3 are appropriately determined according to the manufactured device, but 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 it is particularly suitable for wiring substrates with wiring.

[0111] Then, in the separation process, firstly as follows Figure 2As shown in (c), laser 4 is irradiated at the location on the interface ablation layer 11 where at least one workpiece piece 2 is attached. This irradiation can be performed simultaneously at multiple locations where the workpiece piece 2 is attached, or it can be performed sequentially on these locations. There are no limitations on the irradiation conditions for laser 4, as long as interface ablation can occur. Known laser irradiation devices can be used as the laser irradiation apparatus.

[0112] When irradiated by the aforementioned laser 4, such as Figure 2 As shown in (d), interface ablation can occur at the irradiated location of the interface ablation layer 11. Specifically, by irradiation with laser 4, the components constituting the region of the cured interface ablation layer 11 near the substrate 12 evaporate or volatilize, forming a reaction region 13. Subsequently, the gas generated by the evaporation or volatilization remains between the substrate 12 and the reaction region 13, thereby forming bubbles 5. By forming these bubbles 5, the interface ablation layer 11 is locally deformed at the location of the workpiece piece 2', causing the workpiece piece 2' to peel off from the interface ablation layer 11. Thus, the workpiece piece 2' present at the location where the interface ablation occurs can be placed on the object 3.

[0113] In addition, the reaction zone 13 and bubbles 5 generated by the laser 4 will usually remain after the workpiece pieces 2' are separated. Figure 4 The image shows the morphology of the workpiece pieces 2 separated one by one by the laser irradiation, specifically showing the state after separation (the two on the left), the state during separation (the center), and the state before separation (the two on the right). As shown in the figure, the bubbles 5 after separation are typically slightly smaller than the bubbles during separation.

[0114] The above-described device manufacturing method may also include steps other than preparation, configuration, and separation. For example, grinding, die bonding, wire bonding, molding, inspection, and transfer processes can be performed at any point between the preparation and separation processes.

[0115] In this embodiment, the workpiece processing sheet 1, when having an interface ablation layer 11 containing active energy ray curing components, preferably adopts... Figure 3 The device manufacturing method shown includes at least a preparation step ( Figure 3 (a) of, configuration process ( Figure 3 (b) and curing process ( Figure 3 (c) and separation process ( Figure 3 The four processes are (d) and (e).

[0116] Figure 3 The preparation and configuration steps in the device manufacturing method shown can be compared with... Figure 2 The device manufacturing method shown is implemented in the same manner.

[0117] In the curing process following the preparation and configuration processes, such as Figure 3 As shown in (c), the entire interface ablation layer 11 in the laminate is irradiated with active energy rays 6, thereby solidifying the entire interface ablation layer 11. Thus, the interface ablation layer 11 becomes the solidified interface ablation layer 11'. Furthermore, although... Figure 3 (c) depicts the morphology of the active energy ray 6 irradiating the entire interface ablation layer 11, but the irradiation can also be performed only on the position of the interface ablation layer 11 where at least one workpiece piece 2 is attached, thereby allowing the interface ablation layer 11 to be locally solidified.

[0118] The irradiation of the aforementioned active energy ray 6 can also be carried out using known methods, such as using an ultraviolet irradiation device equipped with a high-pressure mercury lamp, an ultraviolet LED as a light source, or a laser irradiation device used in the separation process described later.

[0119] Then, in the separation process, firstly, as... Figure 3 As shown in (d), the laser 4 is irradiated at the position where at least one workpiece piece 2 is attached to the cured interface ablation layer 11' of the above-mentioned laminate. This irradiation can be performed simultaneously on multiple positions where the workpiece piece 2 is attached, or it can be performed sequentially on these positions. The irradiation conditions for the laser 4 are not limited as long as interface ablation can occur. A known laser irradiation device can be used as the laser irradiation device.

[0120] When irradiated by the aforementioned laser 4, such as Figure 3 As shown in (e), interface ablation can occur at the irradiated location of the cured interface ablation layer 11'. Specifically, by irradiating with laser 4, the components constituting the region of the cured interface ablation layer 11' near the substrate 12 evaporate or volatilize, forming a reaction region 13. Subsequently, the gas generated by the evaporation or volatilization remains between the substrate 12 and the reaction region 13, forming bubbles 5. By forming these bubbles 5, the cured interface ablation layer 11' is locally deformed at the location of the workpiece piece 2', and the workpiece piece 2' separates from the cured interface ablation layer 11'. Thus, the workpiece piece 2' present at the location where interface ablation occurs can be placed on the object 3.

[0121] Furthermore, the reaction zone 13 and bubbles 5 generated by irradiating the laser 4 typically remain after the separation of the workpiece fragment 2'. That is, with... Figure 4 The situation is the same as shown. Typically, the separated bubble 5 is slightly shrunken compared to the separated bubble 5.

[0122] Furthermore, when the laser irradiation device described above is used for both the irradiation of the active energy ray 6 in the curing process and the irradiation of the laser 4 in the separation process, the curing and separation processes can be performed simultaneously. That is, the irradiation of the laser 4 in the separation process can be performed simultaneously as the irradiation of the active energy ray 6 in the curing process, and the local curing and interface ablation of the interface ablation layer 11 can be performed simultaneously. In this case, the peak wavelength of the irradiated laser 4 is preferably 300 nm or more, particularly preferably 310 nm or more, and even more preferably 350 nm or more. In addition, the peak wavelength is preferably 400 nm or less, particularly preferably 390 nm or less, and even more preferably 380 nm or less. By irradiating with the laser 4 having this wavelength, the curing and interface ablation of the interface ablation layer 11 can be easily and effectively performed.

[0123] On the other hand, such as Figure 3 As shown, when the curing and separation processes are performed as independent processes, the peak wavelength of the active energy ray 6 irradiated by 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. Similarly, the peak wavelength of the laser 4 irradiated by 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. In both the curing and separation processes, by irradiating the active energy ray 6 and the laser 4, which respectively have the peak wavelengths described above, the curing and interface ablation of the interface ablation layer 11 can be easily and effectively performed in each process.

[0124] The above Figure 3 The device manufacturing method shown can also include steps other than the preparation, configuration, curing, and separation steps. For example, grinding, die bonding, wire bonding, molding, inspection, and transfer processes can be performed at any point between the preparation and separation steps.

[0125] Based on the device manufacturing 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 miniature 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 or a display having multiple miniature light-emitting diodes as backlights can be manufactured.

[0126] The embodiments described above are provided for the purpose of understanding the present invention and are not intended to limit the present invention. Therefore, the elements disclosed in the above embodiments include all design changes, equivalents, etc., that fall within the technical scope of the present invention.

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

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

[0129] [Example 1-1] (1) Preparation of adhesive composition 80 parts by mass of 2-ethylhexyl acrylate and 20 parts by mass of 2-hydroxyethyl acrylate were polymerized by solution polymerization to obtain a (meth)acrylate polymer. Isoethyl methacrylate (MOI), at 80 mol% relative to the 2-hydroxyethyl acrylate in this (meth)acrylate polymer, was then reacted with the (meth)acrylate polymer to obtain an acrylic polymer (active energy radiation curable component) with active energy radiation curable groups introduced into its side chains. The weight-average molecular weight (Mw) of this acrylic polymer, determined by the method described later, was 1 million.

[0130] A coating liquid of an adhesive composition was obtained by mixing 100 parts by weight (solid component conversion, the same below) of the above-obtained acrylic polymer with active energy-curable groups introduced into the side chain, 3 parts by weight of 1-hydroxycyclohexylphenyl ketone (manufactured by IGM Resins, product name "Omnirad 184") as a photopolymerization initiator, and 3 parts by weight of NF-CO01 (coumarin-based photosensitizer, absorbance at 365 nm of 10 ppm dimethylformamide solution (measured by spectrophotometer): 0.97) manufactured by NIPPON CHEMICAL WORKS CO., LTD. as a photosensitizer.

[0131] (2) Formation of the interface ablation layer (adhesive layer) A release sheet (manufactured by LINTEC CO., LTD., product name "SP-PET381031"), formed by forming a silicone-based release agent layer on one side of a 38 μm thick polyethylene terephthalate film, was coated with the adhesive composition obtained in step (1) above. The resulting coating was then dried by heating. As a result, a laminate consisting of a 5 μm thick interface ablation layer formed by the dried coating and the release sheet was obtained.

[0132] (3) Fabrication of workpiece processing sheet By bonding the surface of the interfacial ablation layer of the laminate obtained in the above process (2) to one side of the polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, product name "T-910 WM19", thickness: 50μm) as the substrate, a workpiece processing sheet with a release liner attached is obtained.

[0133] The weight-average molecular weight (Mw) is the weight-average molecular weight converted from standard polystyrene, determined using gel permeation chromatography (GPC) under the following conditions (GPC determination). <Measurement Conditions> • Measuring device: HLC-8320, manufactured by Tosoh Corporation • GPC column (passes in the following order): Manufactured by Tosoh Corporation TSK gel superH-H TSK gel superHM-H TSK gel superH2000 • Solvent for determination: Tetrahydrofuran • Measurement temperature: 40℃

[0134] [Examples 1-2 and Comparative Example 1-1] Except for changing the content of photopolymerization initiator and photosensitizer as shown in Table 1, the workpiece processing sheet with the release liner attached was obtained in the same manner as in Example 1-1.

[0135] [Examples 1-3] (1) Preparation of adhesive composition The (meth)acrylate polymer (acrylic polymer) was obtained by solution polymerization of 90 parts by weight of 2-ethylhexyl acrylate, 1.75 parts by weight of acryloylmorpholine, 3.5 parts by weight of 2-hydroxyethyl acrylate, 3.5 parts by weight of 4-hydroxybutyl acrylate, and 0.2 parts by weight of acrylic acid. The weight-average molecular weight (Mw) of this acrylic polymer, as determined by the aforementioned method, was 1 million.

[0136] A coating solution of an adhesive composition is obtained by mixing 100 parts by weight of the above-obtained acrylic polymer, 2 parts by weight of hexamethylene diisocyanate (manufactured by Tosoh Corporation, product name "Coronate HL") as a crosslinking agent, and 3 parts by weight of NF-CO01 (manufactured by NIPPON CHEMICAL WORKS CO., LTD., product name "NF-CO01") (coumarin-based photosensitizer, absorbance at 365 nm of 10 ppm dimethylformamide solution (measured by spectrophotometer): 0.97) as a photosensitizer in a solvent.

[0137] In addition to using the obtained adhesive composition, a workpiece processing sheet with a release liner attached was obtained in the same manner as in Examples 1-1.

[0138] [Examples 1-4 to 1-15 and Comparative Examples 1-2] Except for changing the content of crosslinking agent, photosensitizer, and the thickness of the interface ablation layer as shown in Table 1, the workpiece processing sheet with the attached release sheet was obtained in the same manner as in Examples 1-3.

[0139] [Experimental Example 1-1] (Laser Peeling Test) (1) Preparation of chips on the workpiece processing chip (preparation process) A dicing die (manufactured by LINTEC CO.,LTD., product name "D-485H") is attached to the polished surface of a silicon wafer that has been polished to #2000 on one side. Next, a dicing ring frame is attached to the periphery of the aforementioned attachment surface of the dicing die (the portion that does not overlap with the silicon wafer). Further, the dicing die is cut according to the outer diameter of the ring frame. Then, the silicon wafer is diced into chips using a dicing apparatus (manufactured by DISCO Corporation, product name "DFD6362"). The thickness of the silicon wafer used and the dimensions of the diced chips are shown in Table 1.

[0140] Next, a release sheet is peeled off from the workpiece processing sheet manufactured in the embodiments and comparative examples, thereby bonding the exposed surface to the surface of the laminate containing multiple chips obtained in the above manner. Then, a dicing sheet is peeled off from the multiple chips. Thus, the multiple chips are transferred from the dicing sheet to the workpiece processing sheet, resulting in a laminate with multiple chips disposed on the workpiece processing sheet.

[0141] (2) Configuration of laminated bodies (configuration process) Next, the laminate obtained above is configured such that the chip-side surface faces the horizontally mounted support plate. At this time, the laminate is configured so that it is parallel to the support and a small gap is left between them.

[0142] (3) Chip separation based on laser irradiation (separation process) Next, a laser irradiation device (YAG third harmonic (wavelength 355nm) with a pulse width of 20ns and a light intensity of 700mJ / cm²) was used. 2 The laser is used to irradiate the chip through the workpiece processing wafer. The irradiation conditions are set as follows: frequency: 40kHz, irradiation dose: 50μJ / pulse.

[0143] Regarding the illumination at this time, the point-like lasers are irradiated sequentially, with their trajectories forming multiple parallel lines. Furthermore, the area formed by these multiple linear trajectories is irradiated in the center of the chip. The irradiation sequence of the point-like lasers is as follows: starting from one end of a trajectory and irradiating sequentially towards the other, for adjacent trajectories, irradiating sequentially from one end on the same side towards the other, and this operation is repeated.

[0144] Here, irradiation is performed with an irradiation mark diameter of 20 μm and adjacent irradiation marks on the same track spaced 5 μm apart. Further, irradiation is performed with the track spacing shown in Table 1.

[0145] In addition, 100 chips (a group of 10 chips vertically × 10 chips horizontally) are selected from multiple chips, and each of them is irradiated as described above.

[0146] (4) Evaluation For laser stripping performed in the above manner, it was confirmed whether the chip detached from the workpiece wafer, and the adaptability of laser stripping was evaluated based on the following criteria. The results are shown in Table 1. ◎…The proportion of chips that detached well was over 55%. ○…The proportion of chips that are well detached is greater than 0% and less than 55%. The proportion of chips that successfully detached was 0%.

[0147] In addition, the details of the abbreviations, etc., recorded in Table 1 are shown below. 2EHA: 2-Ethylhexyl acrylate HEA: 2-Hydroxyethyl acrylate MOI: Ethyl isocyanate methacrylate ACMO: Acryloylmorpholine 4HBA: 4-Hydroxybutyl acrylate AAc: Acrylic acid

[0148] [Table 1]

[0149] As shown in Table 1, for the workpiece processing wafer in the embodiment, the chip detaches well.

[0150] [Example 2-1] (1) Preparation of adhesive composition 80 parts by mass of 2-ethylhexyl acrylate and 20 parts by mass of 2-hydroxyethyl acrylate were polymerized by solution polymerization to obtain a (meth)acrylate polymer. Isoethyl methacrylate (MOI), with an 80 mol% relative to the 2-hydroxyethyl acrylate content of the (meth)acrylate polymer, was reacted with the (meth)acrylate polymer to obtain an acrylic polymer (active energy radiation curable component) with active energy radiation curable groups introduced into its side chains. The weight-average molecular weight (Mw) of this acrylic polymer, determined by the aforementioned method, was 1 million.

[0151] In a solvent, 100 parts by weight (solid component conversion, the same below) of the above-obtained acrylic polymer with active energy-curable groups introduced into the side chain, 4.69 parts by weight of trimethylolpropane-modified toluene diisocyanate (manufactured by Mitsui Chemicals, Inc., product name "Takenate D-101E") as a crosslinking agent, 3 parts by weight of 1-hydroxycyclohexylphenyl ketone (manufactured by IGM Resins, product name "Omnirad184") as a photopolymerization initiator, and 3 parts by weight of NF-CO01 (coumarin-based photosensitizer, absorbance at 365 nm of 10 ppm dimethylformamide solution (measured by spectrophotometer): 0.97) manufactured by NIPPON CHEMICAL WORKS CO., LTD. were mixed to obtain a coating liquid of adhesive composition.

[0152] (2) Formation of the interface ablation layer (adhesive layer) A release sheet (manufactured by LINTEC CO., LTD., product name "SP-PET381031"), formed by forming a silicone-based release agent layer on one side of a 38 μm thick polyethylene terephthalate film, was coated with the adhesive composition obtained in step (1) above. The resulting coating was then dried by heating. As a result, a laminate consisting of a 5 μm thick interface ablation layer formed by the dried coating and the release sheet was obtained.

[0153] (3) Fabrication of workpiece processing sheet By bonding the surface of the interfacial ablation layer of the laminate obtained in the above process (2) to one side of the polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, product name "T-910 WM19", thickness: 50μm) as the substrate, a workpiece processing sheet with a release liner attached is obtained.

[0154] [Examples 2-2 to 2-16, Examples 2-18 to 2-26, Comparative Examples 2-1 and 2-3 to 2-4] Except for changing the composition of the acrylic polymer, the type and amount of crosslinking agent, the type and amount of photopolymerization initiator, the type and amount of photosensitizer, the amount of ultraviolet absorber, and the thickness of the interface ablation layer as shown in Table 2, a workpiece processing sheet with a release liner attached was obtained in the same manner as in Example 2-1.

[0155] In addition, tris[2,4,6-[2-{4-(octyl-2-methylethyl acetate)oxy-2-hydroxyphenyl}]-1,3,5-triazine (hydroxyphenyltriazine is a UV absorber, manufactured by BASF, product name "Tinuvin477").

[0156] In addition, the details of the abbreviations, etc., recorded in Table 2 are shown below. [Acrylic polymers] 2EHA: 2-Ethylhexyl acrylate HEA: 2-Hydroxyethyl acrylate MOI: Ethyl isocyanate methacrylate ACMO: Acryloylmorpholine MA: Methacrylic acid AA: Acrylic acid [Cross-linking agent] Takenate D-101E: Trimethylolpropane-modified toluene diisocyanate (manufactured by Mitsui Chemicals, Inc., product name "Takenate D-101E") Coronate HL: Hexamethylene diisocyanate (manufactured by Tosoh Corporation, product name "Coronate HL") [Photopolymerization initiator] Omnirad184: 1-Hydroxycyclohexylphenyl ketone (manufactured by IGM Resins, product name "Omnirad184") Omnirad127: 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methyl-1-propanone (manufactured by IGM Resins, product name "Omnirad127") [Photosensitizer] Coumarin-based: Product name "NF-CO01" manufactured by NIPPON CHEMICAL WORKS CO., LTD. (Coumarin-based photosensitizer, absorbance at 365 nm of 10 ppm dimethylformamide solution (measured by spectrophotometer): 0.97) Pyrazoline-based: Product name "NF-PY02" manufactured by NIPPON CHEMICAL WORKS CO., LTD. (Pyrazoline-based photosensitizer, absorbance at 365 nm of 10 ppm ethanol solution (measured by spectrophotometer): 0.53).

[0157] [Example 2-17] The (meth)acrylate polymer was obtained by solution polymerization of 40 parts by weight of 2-ethylhexyl acrylate, 50 parts by weight of methacrylic acid, and 10 parts by weight of acrylic acid. The weight-average molecular weight (Mw) of the acrylic polymer was determined to be 1 million by the aforementioned method.

[0158] 100 parts by weight (solid composition conversion, the same below) of the above-obtained acrylic polymer, 40 parts by weight of 10-functional urethane acrylate (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., product name "UV-5806", weight average molecular weight: 1740) as an active energy ray curable oligomer, 4.69 parts by weight of trimethylolpropane-modified toluene diisocyanate (manufactured by Mitsui Chemicals, Inc., product name "Takenate D-101E") as a crosslinking agent, and 1.5 parts by weight of NF-CO01 (coumarin-based photosensitizer, absorbance at 365 nm of 10 ppm dimethylformamide solution (measured by spectrophotometer): 0.97) manufactured by NIPPON CHEMICAL WORKS CO.,LTD. as a photosensitizer were mixed in a solvent to obtain a coating liquid of adhesive composition.

[0159] Except for using the adhesive composition obtained above and changing the thickness of the interface ablation layer as shown in Table 2, a workpiece processing sheet with a release sheet attached was obtained in the same manner as in Example 2-1.

[0160] [Comparative Example 2-2] Except for changing the content of the crosslinking agent as shown in Table 2, not using the photosensitizer, and changing the thickness of the interface ablation layer as shown in Table 2, the workpiece processing sheet with the release sheet attached was obtained in the same manner as in Examples 2-17.

[0161] [Experimental Example 2-1] (Laser Peeling Test) (1) Preparation of chips on the workpiece processing chip (preparation process) Following the same preparation process as in Example 1-1, a laminate consisting of multiple chips disposed on the workpiece wafer was obtained. The thickness of the silicon wafer used and the dimensions of the diced chips are shown in Table 2.

[0162] (2) Configuration of laminated bodies (configuration process) The stacked body was configured in the same manner as in Test Example 1-1, with the chip-side surface of the stacked body facing the horizontally mounted support plate.

[0163] (3) Irradiation by active energy rays (curing process) Subsequently, an ultraviolet irradiation device (manufactured by LINTEC CO., LTD., product name "RAD-2000") equipped with a high-pressure mercury lamp as a light source was used to irradiate the workpiece-side surface of the aforementioned laminate with ultraviolet light (illuminance: 230mW / cm²). 2 Light intensity: 380 mJ / cm 2 This process solidifies the entire interface ablation layer in the workpiece processing sheet.

[0164] (4) Separation of chips based on laser irradiation (separation process) The chip was irradiated with a laser through the workpiece processing wafer in the same manner as the separation process in Example 1-1. The irradiation trajectories were spaced apart as shown in Table 2.

[0165] (5) Evaluation The evaluation was conducted in the same manner as in Experiment 1-1. The results are shown in Table 2.

[0166] [Table 2]

[0167] As shown in Table 2, for the workpiece processing wafer in the embodiment, the chip detaches well. Industrial applicability

[0168] The workpiece processing sheet of the present invention is suitable for processing various small workpiece pieces such as miniature light-emitting diodes and semiconductor components. Explanation of reference numerals in the attached figures

[0169] 1: Workpiece processing sheet; 11, 11': Interface ablation layer; 12: Substrate; 13: Reaction field; 2, 2': Small workpiece piece; 3: Object; 4: Laser; 5: Bubble; 6: Active energy ray.

Claims

1. A workpiece processing sheet, which is a workpiece processing sheet provided with a base material and an interface ablation layer, wherein, The interface ablation layer is stacked on one side of the substrate and can hold the small workpiece piece, allowing it to undergo interface ablation by laser irradiation. The workpiece piece is characterized by... The interface ablation layer contains a photosensitizer. The absorbance of light at a wavelength of 365 nm, measured for a solution of the photosensitizer dissolved in an organic solvent at a concentration of 10 ppm, is 0.3 or higher.

2. The workpiece processing sheet according to claim 1, characterized in that, The photosensitizer is a heterocyclic compound.

3. The workpiece processing sheet according to claim 1, characterized in that, The photosensitizer is at least one of coumarin-based and pyrazoline-based photosensitizers.

4. The workpiece processing sheet according to claim 1, characterized in that, The content of the photosensitizer in the interface ablation layer is more than 0.1% and less than 10%.

5. The workpiece processing sheet according to claim 1, characterized in that, The content of the ultraviolet absorber in the interface ablation layer is less than 10%.

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

7. The workpiece processing sheet according to claim 1, characterized in that... When the interface ablation layer undergoes interface ablation, bubbles are formed at the location where the interface ablation occurs.

8. The workpiece processing sheet according to claim 1, characterized in that, It is used to: selectively separate any one of a plurality of workpiece pieces held on the opposite side of the interface ablation layer from the interface ablation layer by utilizing the interface ablation that occurs locally in the interface ablation layer.

9. The workpiece processing sheet according to claim 1, characterized in that, The interface ablation layer contains active energy ray curing components.

10. The workpiece processing sheet according to claim 9, characterized in that, It is used to: solidify the interface ablation layer entirely or partially by irradiation with active energy rays, and to locally ablate the interface ablation layer by irradiation with the laser, thereby selectively separating any workpiece piece from the interface ablation layer among a plurality of workpiece pieces held on the surface opposite to the substrate of the interface ablation layer.

11. A method for manufacturing a device, characterized in that, have: A preparation process for preparing a laminate consisting of multiple small workpiece pieces held on the surface of the workpiece processing sheet on the interface ablation layer side as described in any one of claims 1 to 8; The configuration process of arranging the laminate with the workpiece piece side of the laminate facing the object that can accommodate the workpiece piece; and A separation process in which a laser is irradiated at the location where at least one workpiece piece is attached to the interface ablation layer in the laminate, causing interface ablation at the irradiated location of the interface ablation layer, thereby separating the workpiece piece at the location where interface ablation occurs from the workpiece processing sheet, and placing the workpiece piece on the object.

12. A method for manufacturing a device, characterized in that, have: A preparation process for holding a stack of multiple small workpiece pieces on the surface of the workpiece processing sheet on the interface ablation layer side as described in claim 9 or 10. The configuration process of arranging the laminate with the workpiece piece side of the laminate facing the object that can accommodate the workpiece piece; A curing process in which the entire interface ablation layer in the laminate, or the location where at least one workpiece piece is attached to the interface ablation layer in the laminate, is irradiated with active energy rays, thereby curing the entire or partial interface ablation layer; and A laser is irradiated at the location where at least one workpiece piece is attached to the interface ablation layer in the laminate, causing interface ablation at the irradiated location of the interface ablation layer, thereby separating the workpiece piece at the location where interface ablation occurs from the workpiece processing sheet, and placing the workpiece piece on the object in a separation process.

13. The device manufacturing method according to claim 12, characterized in that, After the curing process is completed, the separation process is performed.

14. The device manufacturing method according to claim 12, characterized in that, The laser irradiation in the separation process is also used as the irradiation of the active energy rays in the curing process, thereby simultaneously performing local curing of the interface ablation layer and interface ablation.

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