Work handling sheet and device manufacturing method

Abstract

This workpiece handling sheet 1 is provided with a substrate 12 and an interface ablation layer 11 which is laminated on one surface of the substrate 12 and which can hold small workpieces 2 and perform interface ablation by irradiation with a laser, wherein the interface ablation layer 11 is characterized by containing a UV absorbing agent. This workpiece handling sheet allows favorably handling even fine workpieces.

Description

[Technical Field]

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

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

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

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

[0005] [Patent Document 1] Patent No. 6546278 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, further miniaturization of micro-light-emitting diodes and higher-density mounting of micro-light-emitting diodes are progressing, and in order to address these, there is a need for a means that can handle a large number of micro-light-emitting diodes and other minute workpieces more efficiently than conventional methods such as those described in Patent Document 1.

[0007] This invention has been made in view of the above circumstances, and aims to provide a work handling sheet that can handle even minute workpieces well, and a device manufacturing method using the work handling sheet. [Means for solving the problem]

[0008] To achieve the above objective, firstly, the present invention provides a work handling sheet comprising a base material and an interface ablation layer laminated on one side of the base material, capable of holding small workpieces, and subjected to interface ablation by irradiation with laser light, wherein the interface ablation layer contains an ultraviolet absorber (Invention 1).

[0009] The work handling sheet according to the above invention (Invention 1) has an interface ablation layer containing an ultraviolet absorber, which effectively ablates the interface when irradiated with laser light, thereby enabling good separation of workpiece pieces toward the target object.

[0010] In the above invention (Invention 1), the ultraviolet absorber is preferably an organic compound (Invention 2).

[0011] In the above inventions (Inventions 1 and 2), the ultraviolet absorber is preferably a compound having one or more heterocycles (Invention 3).

[0012] In the above inventions (Inventions 1 to 3), the ultraviolet absorber preferably has at least one of a carbocyclic ring and a heterocyclic ring, and all of the carbocyclic rings and heterocyclic rings in the ultraviolet absorber are monocyclic rings (Invention 4).

[0013] In the above inventions (Inventions 1 to 4), the ultraviolet absorber is preferably a compound having a plurality of aromatic rings (Invention 5).

[0014] In the above inventions (Inventions 1 to 5), the content of the ultraviolet absorber in the interfacial ablation layer is preferably 1% by mass or more and 75% by mass or less (Invention 6).

[0015] In the above inventions (Inventions 1 to 6), it is preferable that the work handling sheet has an absorbance of 2.0 or higher for light with a wavelength of 355 nm (Invention 7).

[0016] In the above inventions (Inventions 1 to 7), it is preferable that the work handling sheet has a transmittance of 1.0% or less for light with a wavelength of 355 nm (Invention 8).

[0017] In the above inventions (Inventions 1 to 8), the interfacial ablation layer is preferably an adhesive layer (Invention 9).

[0018] In the above invention (Invention 9), the adhesive constituting the adhesive layer is preferably an acrylic adhesive (Invention 10).

[0019] In the above inventions (Inventions 1 to 10), it is preferable that the laser light has a wavelength in the ultraviolet region (Invention 11).

[0020] In the above inventions (Inventions 1 to 11), when interfacial ablation is caused in the interfacial ablation layer, it is preferable that blisters are formed at the position where the interfacial ablation has occurred (Invention 12).

[0021] In the above inventions (Inventions 1 to 12), by the locally caused interfacial ablation in the interfacial ablation layer, any one of a plurality of work pieces held on the surface of the interfacial ablation layer opposite to the base material in the interfacial ablation layer is used to selectively separate from the interfacial ablation layer, which is preferable (Invention 13).

[0022] In the above invention (Invention 13), it is preferable that the work piece is obtained by fragmenting the work held on the surface of the interfacial ablation layer opposite to the base material on that surface (Invention 14).

[0023] In the above inventions (Inventions 13 and 14), it is preferable that the work piece is at least one selected from semiconductor components and semiconductor devices (Invention 15).

[0024] In the above inventions (Inventions 13 to 15), it is preferable that the work piece is a light-emitting diode selected from mini light-emitting diodes and micro light-emitting diodes (Invention 16).

[0025] Secondly, the present invention provides a device manufacturing method comprising: a preparation step of preparing a laminate in which a plurality of workpieces are held on the surface of a work handling sheet having a base material and an interface ablation layer containing an ultraviolet absorber laminated on one side of the base material; a placement step of arranging the laminate on an object capable of receiving the workpieces such that the surfaces of the laminate on which the workpieces are held face to each other; and a separation step of irradiating a laser beam to a position on the interface ablation layer of the laminate to which at least one of the workpieces is attached, thereby causing interface ablation at the irradiated position in the interface ablation layer, separating the workpieces located at the positions where interface ablation has occurred from the work handling sheet, and placing the workpieces on the object (Invention 17).

[0026] In the above invention (Invention 17), in the preparation step, it is preferable to obtain the workpiece pieces by separating the workpiece held on the surface of the interface ablation layer opposite to the substrate on that surface (Invention 18).

[0027] In the above inventions (Inventions 17, 18), it is preferable that the workpiece is at least one selected from semiconductor components and semiconductor devices (Invention 19).

[0028] In the above inventions (inventions 17 to 19), it is preferable to use a light-emitting diode selected from mini light-emitting diodes and micro light-emitting diodes as the workpiece to manufacture a light-emitting device comprising a plurality of such light-emitting diodes (invention 20).

[0029] In the above invention (Invention 20), the light-emitting device is preferably a display (Invention 21). [Effects of the Invention]

[0030] The work handling sheet according to the present invention can handle even minute workpieces well, and the device manufacturing method according to the present invention can manufacture devices with excellent performance. [Brief explanation of the drawing]

[0031] [Figure 1] This is a cross-sectional view of a work handling sheet according to one embodiment of the present invention. [Figure 2] This is a cross-sectional view illustrating a device manufacturing method using a work handling sheet according to one embodiment of the present invention. [Figure 3] This is a cross-sectional view illustrating the state of the blister and reaction area created by laser light irradiation. [Modes for carrying out the invention]

[0032] Embodiments of the present invention will be described below. Figure 1 shows a cross-sectional view of a work handling sheet according to one embodiment. The work handling sheet 1 shown in Figure 1 comprises a base material 12 and an interface ablation layer 11 laminated on one side of the base material 12.

[0033] In the work handling sheet 1 according to this embodiment, the interface ablation layer 11 is capable of holding workpieces. That is, the work handling sheet 1 according to this embodiment can hold workpieces laminated on the surface of the interface ablation layer 11 opposite to the substrate 12 in that state.

[0034] Although the specific manner of retention described above is not limited, a preferred example is retention by the interfacial ablation layer 11 exhibiting adhesiveness to the workpiece piece. In this case, it is preferable that the interfacial ablation layer 11 contains an adhesive as one of its constituent components, as will be described later, i.e., it is an adhesive layer.

[0035] Furthermore, the interface ablation layer 11 in this embodiment undergoes interface ablation by irradiation with laser light. That is, the interface ablation layer 11 undergoes localized interface ablation in the region irradiated with the laser light. The laser light is not particularly limited as long as it is capable of causing interface ablation, and may have wavelengths in the ultraviolet, visible, or infrared regions, with a laser light having a wavelength in the ultraviolet region being preferred.

[0036] In this specification, interfacial ablation refers to the process in which some of the components constituting the interfacial ablation layer 11 evaporate or volatilize due to the energy of the laser light, and the resulting gas accumulates at the interface between the interfacial ablation layer 11 and the substrate 12, creating a void (blister). In this case, the shape of the interfacial ablation layer 11 changes due to the blister, causing the workpiece fragments to peel off from the interfacial ablation layer 11 and separate.

[0037] Furthermore, the interface ablation layer 11 in this embodiment contains an ultraviolet absorber. The presence of the ultraviolet absorber in the interface ablation layer 11 improves the efficiency of the interface ablation layer 11 in receiving energy from the laser light. As a result, interface ablation occurs effectively, and it becomes possible to separate the held workpiece pieces well from the interface ablation layer 11. In particular, the amount of laser light required to achieve sufficient separation of the workpiece pieces is reduced, which reduces the operating cost of the laser light irradiation device, improves accuracy by making it easier to separate only the target workpiece pieces well, and also prevents damage to the device due to excessive laser light irradiation.

[0038] 1. Interfacial ablation layer The specific configuration and composition of the interface ablation layer 11 in this embodiment are not particularly limited, as long as it is capable of holding workpiece pieces, has the property of undergoing interface ablation by laser irradiation, and contains an ultraviolet absorber.

[0039] From the viewpoint of easily exhibiting the property of being able to hold small workpieces, it is preferable that the interface ablation layer 11 contains an adhesive as one of its constituent components, as described above. When the interface ablation layer 11 contains an adhesive, it is preferable that the interface ablation layer 11 is made of an adhesive composition containing an ultraviolet absorber.

[0040] (1) UV absorbers The type of UV absorber in this embodiment is not particularly limited. The UV absorber in this embodiment may be an organic compound or an inorganic compound, but an organic compound is preferred from the viewpoint of easily generating good interfacial ablation.

[0041] When the UV absorber is an organic compound, preferred examples of such UV absorbers include hydroxyphenyltriazine-based UV absorbers, benzophenone-based UV absorbers, benzotriazole-based UV absorbers, benzoate-based UV absorbers, benzoxazinon-based UV absorbers, phenylsalicylate-based UV absorbers, cyanoacrylate-based UV absorbers, nickel complex salt-based UV absorbers, hydroquinone-based UV absorbers, salicylic acid-based UV absorbers, malonic acid ester-based UV absorbers, and oxalic acid-based UV absorbers. These may be used individually or in combination of two or more.

[0042] Among the UV absorbers mentioned above, it is preferable to use at least one of the following: a hydroxyphenyltriazine-based UV absorber, a benzophenone-based UV absorber, and a benzotriazole-based UV absorber, from the viewpoint of having good absorption at the third harmonic of YAG (355 nm) and readily generating good interfacial ablation. In particular, it is preferable to use a hydroxyphenyltriazine-based UV absorber.

[0043] The above hydroxyphenyltriazine-based UV absorbers include 2-[4-(octyl-2-methylethanolate)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)]-1,3,5-triazine, 2-[4-(2-hydroxy-3-dodecyloxypropyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-(2-hydroxy-3- [Tridecyloxypropyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-(2-hydroxy-3-(2'-ethyl)hexyloxy]-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine, 2, Examples include 4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3-5-triazine, 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, and tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine. These may be used individually or in combination of two or more. Among these, it is preferable to use at least one of tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine and 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine.

[0044] Furthermore, if the UV absorber is an organic compound, it is preferable that the UV absorber has one or more heterocycles as a characteristic of its chemical structure. In this case, the number of heterocycles is preferably four or less, and particularly preferably one.

[0045] Furthermore, as another characteristic of the chemical structure, it is preferable that the ultraviolet absorber in this embodiment has at least one of a carbocyclic ring and a heterocyclic ring, and that all of the carbocyclic rings and heterocyclic rings in the ultraviolet absorber are monocyclic rings.

[0046] As a further characteristic of the chemical structure, the ultraviolet absorber in this embodiment is preferably a compound having multiple aromatic rings. In this case, the number of aromatic rings is preferably two or more. Furthermore, the number of aromatic rings is preferably six or less, and particularly preferably three or less.

[0047] In the chemical structural characteristics described above, each heterocycle preferably has at least one element other than carbon selected from nitrogen, oxygen, phosphorus, sulfur, silicon, and selenium, and is particularly preferably at least one selected from nitrogen, oxygen, phosphorus, and sulfur. Furthermore, there is no particular limit to the number of atoms constituting the ring structure of the heterocycle; for example, it is preferably 3 to 9, and particularly preferably 5 to 6. Specific examples of preferred heterocycles include triazine, benzotriazole, thiophene, pyrrole, imidazole, pyridine, and pyrazine.

[0048] Furthermore, regarding the chemical structural characteristics described above, preferred examples of aromatic rings include benzene, naphthalene, anthracene, biphenyl, and triphenyl.

[0049] An example of an ultraviolet absorber having the chemical structural characteristics described above is the ultraviolet absorber having the structure of formula (1) below (tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine).

[0050] [ka]

[0051] In this embodiment, the content of the ultraviolet absorber in the interfacial ablation layer 11 is preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 3% by mass or more, and even more preferably 5% by mass or more. A content of 1% by mass or more of ultraviolet absorber allows the interfacial ablation layer 11 to efficiently absorb laser light, thereby facilitating good interfacial ablation. Furthermore, in this embodiment, the content of the ultraviolet absorber in the interfacial ablation layer 11 is preferably 75% by mass or less, more preferably 60% by mass or less, particularly preferably 50% by mass or less, and even more preferably 20% by mass or less. A content of 75% by mass or less of ultraviolet absorber results in an appropriate viscosity for the material used to form the interfacial ablation layer 11, making it easier to ensure good film-forming properties.

[0052] Furthermore, if the interfacial ablation layer 11 in this embodiment is formed from an adhesive composition described later, the ultraviolet absorber may be incorporated into this adhesive composition. In that case, the amount of ultraviolet absorber incorporated into the adhesive composition is preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 3% by mass or more, and even more preferably 5% by mass or more. When the amount of ultraviolet absorber is 1% by mass or more, the interfacial ablation layer 11 efficiently absorbs laser light, thereby making it easier to perform interfacial ablation. Furthermore, when the amount of ultraviolet absorber incorporated into the adhesive composition is preferably 75% by mass or less, more preferably 60% by mass or less, particularly preferably 50% by mass or less, and even more preferably 20% by mass or less. When the amount of ultraviolet absorber is 75% by mass or less, the resulting adhesive is more likely to exhibit the desired adhesive strength.

[0053] (2) Adhesive As described above, the interfacial ablation layer 11 in this embodiment may contain an adhesive in addition to the ultraviolet absorber. In this case, it is preferable that the interfacial ablation layer 11 is formed from an adhesive composition containing an ultraviolet absorber.

[0054] The adhesive described above is not particularly limited, as long as it can exert sufficient holding power (adhesion) to the adherend, such as a small piece of workpiece. Examples of such adhesives include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, and polyvinyl ether adhesives. Among these, acrylic adhesives are preferred because they easily exhibit the desired adhesive strength.

[0055] The above-mentioned acrylic adhesive is an acrylic adhesive that uses an acrylic polymer (A) as the base polymer. The weight-average molecular weight (Mw) of the acrylic polymer (A) is preferably 10,000 or more, and particularly preferably 100,000 or more. Furthermore, the weight-average molecular weight (Mw) is preferably 2,000,000 or less, and more preferably 1,500,000 or less. A weight-average molecular weight of 10,000 or more for the acrylic polymer (A) makes it easier to increase the cohesive force of the resulting adhesive strength and makes it easier to suppress adhesive residue on separated workpiece pieces. Furthermore, a weight-average molecular weight of 2,000,000 or less makes it easier to obtain a coating film with a stable interfacial ablation layer. Note that the weight-average molecular weight (Mw) in this specification is a value on a standard polystyrene basis measured by gel permeation chromatography (GPC).

[0056] Furthermore, the glass transition temperature (Tg) of the acrylic polymer (A) is preferably -70°C or higher, and particularly preferably -60°C or higher. Also, the glass transition temperature (Tg) is preferably 20°C or lower, and particularly preferably 10°C or lower. Having the glass transition temperature (Tg) of the acrylic polymer (A) within the above range makes it easier to achieve the desired adhesive strength while simultaneously achieving the desired cohesive strength.

[0057] The above-mentioned acrylic polymer (A) preferably contains at least a (meth)acrylic acid ester monomer as a constituent monomer, and preferably has a functional group that can react with the functional group of the crosslinking agent (B) described later (hereinafter also referred to as a "reactive functional group").

[0058] The above (meth)acrylic acid ester monomers specifically include alkyl(meth)acrylates with 1 to 18 carbon atoms in the alkyl group, such as methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, pentyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, isooctyl(meth)acrylate, n-octyl(meth)acrylate, n-nonyl(meth)acrylate, isononyl(meth)acrylate, decyl(meth)acrylate, and lauryl(meth)acrylate; cycloalkyl(meth)acrylates with approximately 1 to 18 carbon atoms in the cycloalkyl group, benzyl(meth)acrylate, isobornyl(meth)acrylate, etc. Examples include acrylates, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and imide (meth)acrylate; hydroxyl group-containing (meth)acrylates such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate; and epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, (3,4-epoxycyclohexyl)methyl (meth)acrylate, and 3-epoxycyclo-2-hydroxypropyl (meth)acrylate.

[0059] Furthermore, monomers other than (meth)acrylic acid ester monomers, such as acrylic acid, methacrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide, may be copolymerized. These may be used individually or in combination of two or more.

[0060] The acrylic polymer (A), by containing reactive functional groups, reacts with the functional groups of the crosslinking agent (B), described later, to form a three-dimensional network structure, thereby increasing the cohesiveness of the interfacial ablation layer. Examples of reactive functional groups in the acrylic polymer (A) include carboxyl groups, amino groups, epoxy groups, and hydroxyl groups, but it is preferable to include hydroxyl groups because they react selectively with organic polyvalent isocyanate compounds, which are preferably used as crosslinking agents, as described later.

[0061] Reactive functional groups can be introduced into acrylic polymer (A) by constructing an acrylic polymer (A) using monomers having reactive functional groups, such as the hydroxyl group-containing (meth)acrylate and acrylic acid mentioned above.

[0062] The proportion of monomers having reactive functional groups (hereinafter also referred to as reactive group-containing monomers) in the total constituent monomers of the acrylic polymer (A) is preferably 0.3% by mass or more, and particularly preferably 0.5% by mass or more. Furthermore, the above proportion is preferably 40% by mass or less, and particularly preferably 20% by mass or less. By including reactive group-containing monomers within this range, it becomes easier to achieve the desired adhesive strength while also achieving the desired cohesive strength.

[0063] Furthermore, the acrylic polymer (A) preferably contains the above-mentioned alkyl (meth)acrylate as a constituent monomer, more preferably alkyl (meth)acrylate having 1 to 10 carbon atoms in the alkyl group, and particularly preferably alkyl (meth)acrylate having 4 to 8 carbon atoms in the alkyl group. When the acrylic polymer (A) contains the above-mentioned alkyl (meth)acrylate, the proportion of alkyl (meth)acrylate in the total constituent monomers of the acrylic polymer (A) is preferably 30% by mass or more, and particularly preferably 35% by mass or more. Moreover, the above proportion is preferably 99% by mass or less, and particularly preferably 95% by mass or less. By including alkyl (meth)acrylate within this range, it becomes easier to achieve the desired adhesive strength while achieving the desired cohesive strength.

[0064] The use of a crosslinking agent (B) is preferable from the viewpoint of easily adjusting the storage modulus of the interfacial ablation layer 11 to a desired range. As the crosslinking agent (B), a polyfunctional compound that has reactivity with reactive functional groups of the acrylic polymer (A) or the like can be used. Examples of such polyfunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts, and reactive phenolic resins.

[0065] The amount of crosslinking agent (B) is preferably 0.001 parts by mass or more, particularly preferably 0.1 parts by mass or more, and more preferably 0.2 parts by mass or more, per 100 parts by mass of acrylic polymer (A). Furthermore, the amount of crosslinking agent (B) is preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of acrylic polymer (A).

[0066] The adhesive constituting the interfacial ablation layer 11 may be an adhesive that is curable by active energy rays. Such an active energy ray-curable adhesive can be one of known types; for example, the one disclosed in International Publication No. 2018 / 084021 can be used.

[0067] In addition to the components described above, other additives may be added to the adhesive composition for forming the interfacial ablation layer 11. Examples of such additives include tackifiers, coloring materials such as dyes and pigments, flame retardants, fillers, and antistatic agents. From the viewpoint of facilitating good separation of workpiece fragments, it is preferable that the adhesive composition does not contain a gas generating agent. If a gas generating agent is used, gas may be generated throughout the interfacial ablation layer 11. In that case, it may become difficult to cause interfacial ablation only at the intended location and separate only the workpiece fragments located there, making it difficult to achieve good separation of workpiece fragments.

[0068] (3) Thickness of the interfacial ablation layer In this embodiment, the thickness of the interface ablation layer 11 is preferably 3 μm or more, particularly preferably 20 μm or more, and even more preferably 25 μm or more. Furthermore, the thickness of the interface ablation layer 11 is preferably 100 μm or less, particularly preferably 50 μm or less, and even more preferably 40 μm or less. Having the thickness of the interface ablation layer 11 within the above range makes it easier to achieve both the retention of workpiece pieces on the interface ablation layer 11 and the separation of workpiece pieces by interface ablation.

[0069] 2. Base material The base material 12 in this embodiment is not particularly limited in terms of its composition or physical properties. From the viewpoint of making it easier for the work handling sheet 1 to perform the desired function, it is preferable that the base material 12 be made of a resin. When the base material 12 is made of a resin, examples of such resins include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resins such as polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, ethylene-norbornene copolymer, and norbornene resin; ethylene-vinyl acetate copolymer; ethylene copolymer resins such as ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate copolymer, and other ethylene-(meth)acrylic acid ester copolymers; polyvinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer; (meth)acrylic acid ester copolymer; polyurethane; polyimide; polystyrene; polycarbonate; and fluororesin. Furthermore, the resin constituting the base material 12 may be a crosslinked version of the above-mentioned resins or a modified version such as an ionomer of the above-mentioned resins. Furthermore, the base material 12 may be a single-layer film made of the resin described above, or it may be a laminated film formed by laminating multiple such films. In this laminated film, the materials constituting each layer may be of the same type or different types.

[0070] In this embodiment, the surface of the substrate 12 may be subjected to surface treatment such as oxidation or embossing, or primer treatment, in order to improve adhesion to the interfacial ablation layer 11. Examples of oxidation methods include corona discharge treatment, plasma discharge treatment, chromium oxidation (wet), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment. Examples of embossing methods include sandblasting and thermal spraying.

[0071] In this embodiment, the substrate 12 may contain various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, and fillers. Furthermore, if the interfacial ablation layer 11 contains a material that hardens with active energy rays, it is preferable that the substrate 12 is permeable to active energy rays.

[0072] The method for manufacturing the base material 12 in this embodiment is not particularly limited as long as it is manufactured from a resin. For example, it can be manufactured by forming the resin into a sheet using a melt extrusion method such as a T-die method or a circular die method; a calendering method; a solution method such as a dry method or a wet method.

[0073] In this embodiment, the thickness of the base material 12 is preferably 10 μm or more, particularly preferably 30 μm or more, and even more preferably 50 μm or more. Furthermore, the thickness of the base material 12 is preferably 500 μm or less, more preferably 300 μm or less, particularly preferably 200 μm or less, even more preferably 150 μm or less, and most preferably 100 μm or less. When the thickness of the base material 12 is within the above range, the work handling sheet 1 will have a predetermined balance of rigidity and flexibility, making it easier to handle small workpieces well.

[0074] 3. Release sheet In this embodiment, if the interface ablation layer 11 includes an adhesive as one of its constituent components, a release sheet may be laminated on the surface of the interface ablation layer 11 opposite to the substrate 12 for the purpose of protecting that surface until it is attached to the workpiece.

[0075] The composition of the release sheet described above is arbitrary, and an example is a plastic film that has been treated with a release agent. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, silicone-based, fluorine-based, and long-chain alkyl-based agents can be used, and among these, silicone-based agents are preferred because they are inexpensive and provide stable performance.

[0076] There are no particular restrictions on the thickness of the release sheet mentioned above; for example, it may be between 20 μm and 250 μm.

[0077] 4. Other configurations In the work handling sheet 1 according to this embodiment, an adhesive layer may be laminated on the side of the interface ablation layer 11 opposite to the substrate 12. In this sheet, a workpiece can be attached to the side of the adhesive layer opposite to the interface ablation layer 11, and by dicing the adhesive layer together with the workpiece, a workpiece piece can be obtained in which individualized adhesive layers are laminated. The chip can be easily fixed to the object on which the workpiece piece is mounted by these individualized adhesive layers. As the material constituting the adhesive layer described above, it is preferable to use one that contains a thermoplastic resin and a low molecular weight thermosetting adhesive component, or one that contains a B-stage (semi-cured) thermosetting adhesive component.

[0078] Furthermore, in the work handling sheet 1 according to this embodiment, a protective film forming layer may be laminated on the side of the interface ablation layer 11 opposite to the substrate 12. In such a sheet, a workpiece can be attached to the side of the protective film forming layer opposite to the interface ablation layer 11, and the protective film forming layer can be diced together with the workpiece to obtain workpiece pieces with laminated individual protective film forming layers. Preferably, a workpiece with a circuit formed on one side is used, and in this case, the protective film forming layer is usually laminated on the side opposite to the side with the circuit. By curing the individual protective film forming layers at a predetermined timing, a protective film with sufficient durability can be formed on the workpiece pieces. Preferably, the protective film forming layer is made of an uncured curable adhesive.

[0079] 5. Physical properties of work handling sheets The work handling sheet according to this embodiment preferably has an absorbance of 2.0 or higher, more preferably 2.5 or higher, particularly preferably 3.0 or higher, and even more preferably 3.5 or higher, when it comes to light with a wavelength of 355 nm. An absorbance of 2.0 or higher when light with a wavelength of 355 nm reduces the amount of ultraviolet light reaching the workpiece during laser irradiation, effectively suppressing surface damage to the workpiece while separating it. The upper limit of the absorbance is not particularly limited and may be, for example, 6.0 or lower. Details of the method for measuring the absorbance are described in the test examples below.

[0080] The work handling sheet according to this embodiment preferably has a transmittance of 1.0% or less, more preferably 0.5% or less, particularly preferably 0.3% or less, and even more preferably 0.1% or less, for light with a wavelength of 355 nm. By having a transmittance of 0.3% or less for light with a wavelength of 355 nm, the amount of ultraviolet light reaching the workpiece can be reduced when laser light is irradiated, making it possible to separate the workpiece while effectively suppressing damage to the surface of the workpiece. The lower limit of the above transmittance is not particularly limited and may be, for example, 0.00001% or more, and particularly preferably 0.0001% or more. Furthermore, the details of the method for measuring the above transmittance are as described in the test examples below.

[0081] In the work handling sheet according to this embodiment, the adhesive force to the mirror surface of the silicon wafer is preferably 10 mN / 25 mm or more, particularly preferably 100 mN / 25 mm or more, and even more preferably 200 mN / 25 mm or more. An adhesive force of 90 mN / 25 mm or more makes it easier to securely fix adherends such as workpiece pieces to the work handling sheet, resulting in superior handling performance. Furthermore, an adhesive force of 30,000 mN / 25 mm or less is preferable, particularly preferably 15,000 mN / 25 mm or less, and even more preferably 10,000 mN / 25 mm or less. An adhesive force of 30,000 mN / 25 mm or less makes it easier to separate workpiece pieces by laser irradiation.

[0082] 6. Method for manufacturing a work handling sheet The method for manufacturing the work handling sheet 1 according to this embodiment is not particularly limited. For example, the interface ablation layer 11 may be formed directly on the substrate 12, or the interface ablation layer 11 may be formed on a process sheet and then transferred onto the substrate 12.

[0083] If the interfacial ablation layer 11 contains an adhesive as one of its constituent components, the formation of the interfacial ablation layer 11 can be carried out by known methods. For example, a coating solution containing an adhesive composition for forming the interfacial ablation layer 11, and optionally a solvent or dispersion medium, can be prepared. Then, the coating solution can be applied to one side of the substrate or the release surface of the release sheet (hereinafter sometimes referred to as the "release surface"). Subsequently, the resulting coating film can be dried to form the interfacial ablation layer 11.

[0084] The coating solution described above can be applied by known methods, such as bar coating, knife coating, roll coating, blade coating, die coating, gravure coating, etc. The properties of the coating solution are not particularly limited as long as it can be applied, and it may contain components for forming the interface ablation layer 11 as a solute or as a dispersed phase. Furthermore, if the interface ablation layer 11 is formed on a release sheet, the release sheet may be peeled off as a process material, or it may protect the interface ablation layer 11 until it is attached to the adherend.

[0085] If the adhesive composition for forming the interfacial ablation layer 11 contains the aforementioned crosslinking agent, it is preferable to promote the crosslinking reaction between the polymer components in the coating film and the crosslinking agent by changing the drying conditions (temperature, time, etc.) or by separately performing a heat treatment, thereby forming a crosslinked structure with a desired density within the interfacial ablation layer 11. Furthermore, in order to allow the above-mentioned crosslinking reaction to proceed sufficiently, curing may be performed after the completion of the work handling sheet 1, for example, by leaving it undisturbed in an environment of 23°C and 50% relative humidity for several days.

[0086] 7. How to use the work handling sheet The work handling sheet 1 according to this embodiment can be suitably used for handling small workpieces. As described above, in the work handling sheet 1 according to this embodiment, the interface ablation layer 11 is efficiently subjected to interface ablation by irradiation with laser light, so that small workpieces held on the interface ablation layer 11 can be separated to predetermined positions with high precision.

[0087] One example of how to use the work handling sheet 1 according to this embodiment is to selectively separate any work piece from the interface ablation layer 11 by locally generated interface ablation in the interface ablation layer 11, which is held on the surface of the interface ablation layer 11 opposite to the substrate 12.

[0088] In the above method of use, the multiple workpiece pieces held on the interface ablation layer 11 may be obtained by dicing a workpiece (the material for the workpiece pieces) held on the surface of the interface ablation layer 11 opposite to the substrate 12 on that surface. That is, the workpiece pieces may be obtained by dicing a workpiece on the interface ablation layer 11. Alternatively, the workpiece pieces may be formed independently of the workpiece handling sheet 1 according to this embodiment and placed on the interface ablation layer 11.

[0089] Furthermore, if the work handling sheet 1 according to this embodiment includes the aforementioned adhesive layer and protective film forming layer, it is preferable to dic these layers and the workpiece on the interface ablation layer 11. This makes it possible to obtain workpiece pieces in which these layers are individually separated and laminated.

[0090] The shape and size of the workpiece pieces in this embodiment are not particularly limited, but in terms of size, the workpiece pieces have an area of ​​10 μm when viewed from above. 2 Preferably, it is 100 μm or more, and especially 100 μm2 It is preferable that the above conditions are met. Furthermore, the workpiece piece has an area of ​​1 mm when viewed from above. 2 Preferably the following, and especially 0.25 mm 2 The following is preferable. Furthermore, regarding the dimensions of the workpiece, if the workpiece is rectangular, the smallest side of the workpiece is preferably 2 μm or more, particularly preferably 5 μm or more, and even more preferably 10 μm or more. Furthermore, the smallest side is preferably 1 mm or less, particularly preferably 0.5 mm or less. Specific examples of the dimensions of a rectangular workpiece include 2 μm × 5 μm, 10 μm × 10 μm, 0.5 mm × 0.5 mm, 1 mm × 1 mm, etc. The workpiece handling sheet 1 according to this embodiment can handle such fine workpieces well, especially fine workpieces that are difficult to separate from the sheet by needle thrusting. On the other hand, the workpiece handling sheet 1 according to this embodiment has an area of ​​1 mm 2 Anything exceeding (for example, 1 mm) 2 ~2000mm 2 It can also handle relatively large workpieces, such as those with a thickness of 1 to 10,000 μm (for example, 10 to 1,000 μm), with good performance.

[0091] Examples of workpiece pieces include semiconductor components and semiconductor devices, and more specifically, micro light-emitting diodes, power devices, and MEMS (Micro Electro Mechanical Systems). Among these, the workpiece piece is preferably a light-emitting diode, and in particular, it is preferably a light-emitting diode selected from mini light-emitting diodes and micro light-emitting diodes. In recent years, the development of devices in which mini light-emitting diodes and micro light-emitting diodes are arranged at high density has been considered, and in the manufacture of such devices, the workpiece handling sheet 1 according to this embodiment, which can handle these light-emitting diodes with high precision, is very suitable.

[0092] Below, a device manufacturing method will be described as a specific example of the use of Work Handling Sheet 1, based on Figure 2. This device manufacturing method comprises at least three steps: a preparation step (Figure 2(a)), a placement step (Figure 2(b)), and a separation step (Figures 2(c) and (d)).

[0093] In the preparation step, as shown in Figure 2(a), a laminate is prepared in which a plurality of workpiece pieces 2 are held on the surface of the work handling sheet 1 according to this embodiment, on the side facing the interface ablation layer 12. This laminate may be prepared by placing separately prepared workpiece pieces 2 on the work handling sheet 1, or by dicing (i.e., separating) the workpiece held on the surface facing the interface ablation layer 11. This dicing can be carried out by known methods.

[0094] As mentioned above, there are no particular limitations on the shape or size of the workpiece 2, and the preferred size is also as mentioned above. Specific examples of workpiece 2 include semiconductor components and semiconductor devices, as mentioned above, and in particular, light-emitting diodes such as miniature and microature light-emitting diodes.

[0095] In the subsequent arrangement step, as shown in Figure 2(b), the laminate is positioned so that the side of the laminate facing the workpiece 2 is facing the object 3 capable of receiving the workpiece 2. The object 3 is determined appropriately depending on the device to be manufactured, but when the workpiece 2 is a light-emitting diode, specific examples of the object 3 include substrates, sheets, reels, etc., and a wiring board with wiring is particularly preferred.

[0096] Subsequently, in the separation process, as shown in Figure 2(c), laser light is first irradiated onto the interface ablation layer 11 of the laminate where at least one workpiece 2 is attached. This irradiation may be performed simultaneously on multiple locations where workpiece 2 is attached, or it may be performed sequentially on those locations. The irradiation conditions for the laser light are not limited as long as they are capable of causing interface ablation. Known equipment can be used for irradiation.

[0097] As shown in Figure 2(d), the above irradiation can cause interfacial ablation to occur at the irradiated location in the interfacial ablation layer 11. Specifically, the irradiation of laser light causes the components constituting the region of the interfacial ablation layer 11 proximal to the substrate 12 to evaporate or volatilize, forming a reaction region 13. The gas generated by the evaporation or volatilization then accumulates between the substrate 11 and the reaction region 13, forming a blister 5. The formation of the blister 5 causes the interfacial ablation layer 11 to deform locally at the location of the workpiece 2', and the workpiece 2' separates as if peeled off from the interfacial ablation layer 11. As a result, the workpiece 2' located at the location where the interfacial ablation occurred can be placed on the object 3.

[0098] The reaction region 13 and blister 5 generated by the laser irradiation usually remain even after the separation of the workpiece 2'. Figure 3 shows the process of separating the workpiece 2' by sequentially irradiating it with laser light, and in particular, the state after separation (two on the left), the state during separation (center), and the state before separation (two on the right) are shown. As shown in the figure, the blister 5 after separation is usually somewhat deflated compared to the blister 5 during separation.

[0099] If the interfacial ablation layer 11 contains an active energy ray curable adhesive as one of its constituent components, the interfacial ablation layer 11 may be cured by irradiation with the laser light described above. This curing may reduce the adhesive force of the interfacial ablation layer 11 to the workpiece 2, and in combination with the effect of the interfacial ablation described above, good separation of the workpiece 2' may occur. Alternatively, the interfacial ablation layer 11 may be subjected to active energy ray irradiation different from the laser light irradiation described above, thereby reducing the adhesive force to the workpiece 2. Such active energy ray irradiation may be performed before or after the laser light irradiation. Furthermore, the active energy ray irradiation may be performed locally on the interfacial ablation layer 11, or on the entire surface of the interfacial ablation layer 11. The irradiation conditions and irradiation apparatus for the active energy ray irradiation described above are not particularly limited, and known conditions and known apparatus can be used.

[0100] The device manufacturing method described above may include steps other than the preparation, placement, and separation steps. For example, grinding, die bonding, wire bonding, molding, inspection, transfer, etc., may be performed at any time between the preparation and separation steps.

[0101] According to the device manufacturing method described above, various devices can be manufactured by appropriately selecting the workpiece 2 and target object 3 to be used. For example, if a light-emitting diode selected from mini light-emitting diodes and micro light-emitting diodes is used as the workpiece 2, a light-emitting device equipped with multiple such light-emitting diodes can be manufactured, and more specifically, a display can be manufactured. In particular, a display equipped with micro light-emitting diodes as pixels, or a display equipped with multiple mini light-emitting diodes as a backlight can be manufactured.

[0102] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit it. Accordingly, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0103] For example, other layers may be laminated between the interface ablation layer 11 and the substrate 12 in the work handling sheet 1 according to this embodiment, or on the surface of the substrate 12 opposite to the interface ablation layer 11. A specific example of such other layer is an adhesive layer. In this case, the separation process described above can be performed with the side with the adhesive layer attached to a support base (a transparent substrate such as a glass plate).

[0104] The adhesive constituting the above adhesive layer is not particularly limited, but it is preferable that it does not easily absorb or block active energy rays. In this case, when laser light is irradiated through the adhesive layer, the laser light can easily reach the interface ablation layer 11, making it easier to produce good interface ablation. Specifically, it is preferable to use an adhesive that does not have active energy ray curability as the adhesive constituting the above adhesive layer, and it is particularly preferable to use an adhesive that does not contain an active energy ray curability component. By using an adhesive that does not have active energy ray curability, the adhesive layer will not harden even when irradiated with the above laser light, thereby preventing unintended peeling of the work handling sheet 1 from the transparent substrate. The thickness of the above adhesive layer is not particularly limited, but for example, it is preferably 5 to 50 μm. [Examples]

[0105] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0106] [Example 1] (1) Preparation of adhesive composition An acrylic polymer was obtained by polymerizing 80 parts by mass of 2-ethylhexyl acrylate and 20 parts by mass of 2-hydroxyethyl acrylate using a solution polymerization method. The weight-average molecular weight (Mw) of this acrylic polymer was measured by the method described later and was found to be 600,000.

[0107] 100 parts by mass (based on solid content, the same applies hereafter) of the acrylic polymer obtained above, 0.94 parts by mass of trimethylolpropane-modified tolylene diisocyanate (manufactured by Tosoh Corporation, trade name "Coronate L") as a crosslinking agent, and 2.0 parts by mass of tris[2,4,6-[2-{4-(octyl-2-methylethanol)oxy-2-hydroxyphenyl}]-1,3,5-triazine (hydroxyphenyltriazine-based ultraviolet absorber, manufactured by BASF, product name "Tinuvin 477") as an ultraviolet absorber were mixed in a solvent to obtain a coating solution for an adhesive composition.

[0108] (2) Formation of an interfacial ablation layer (adhesive layer) A release sheet (Lintec Corporation, product name "SP-PET381031"), which has a silicone-based release agent layer formed on one side of a 38 μm thick polyethylene terephthalate film, was coated with the adhesive composition solution obtained in step (1) above, and the resulting coating film was dried by heating. As a result, a laminate was obtained in which a 30 μm thick interfacial ablation layer formed by the drying of the coating film and the release sheet were laminated together.

[0109] (3) Preparation of work handling sheet By bonding the interfacial ablation layer side of the laminate obtained in step (2) above to one side of a polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, product name "T-910 WM19", thickness: 50 μm) as a base material, a work handling sheet with a release sheet attached was obtained.

[0110] Here, the weight-average molecular weight (Mw) mentioned above is the weight-average molecular weight on a standard polystyrene basis, measured using gel permeation chromatography (GPC) under the following conditions (GPC measurement). <Measurement conditions> • Measuring device: Tosoh Corporation, HLC-8320 • GPC column (passes through in the following order): Manufactured by Tosoh Corporation TSK Gel Super H-H TSK gel superHM-H TSK Gel Super H2000 • Measurement solvent: tetrahydrofuran ·Measurement temperature: 40℃

[0111] [Examples 2-14 and Comparative Examples 1-2] Work handling sheets were manufactured in the same manner as in Example 1, except that the crosslinking agent content and the type and content of the ultraviolet absorber were changed as shown in Table 1.

[0112] [Example 15] A work handling sheet was manufactured in the same manner as in Example 1, except that a resin composition containing an ethylene-methacrylic acid copolymer (manufactured by Mitsui DuPont Polychemicals, product name "Nucrel NH903C") was used as the base material, and an 80 μm thick base material (polyolefin base material) was obtained by extruding it using a small T-die extruder (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name "Laboplastmill"), and the content of the ultraviolet absorber was changed as shown in Table 1.

[0113] [Test Example 1] (Evaluation of suitability for laser lift-off) (1) Preparation of the chip on the work handling sheet (preparation process) (1-1) Examples 1-13 and 15 and Comparative Examples 1-2 On one side of a silicon wafer (#2000, thickness: 350 μm), the adhesive surface of a dicing sheet (manufactured by Lintec Corporation, product name "D-485H") was attached. Subsequently, a dicing ring frame was attached to the peripheral portion of the adhesive surface in the dicing sheet (a position that does not overlap with the silicon wafer). Furthermore, the dicing sheet was cut according to the outer diameter of the ring frame. Then, using a dicing device (manufactured by DISCO Corporation, product name "DFD6362"), the silicon wafer was diced into chips having a size of 300 μm × 300 μm. Thereafter, ultraviolet rays (irradiance 230 mW / cm 2 , light quantity 190 mJ / cm 2 ) were irradiated. As a result, a laminate in which a plurality of chips were provided on the dicing sheet was obtained.

[0114] Subsequently, the release sheet was peeled off from the work handling sheets manufactured in the examples and comparative examples, and the exposed surface thereby exposed was bonded to the surface on which the plurality of chips in the laminate obtained as described above were present. Then, the dicing sheet was peeled off from the plurality of chips. As a result, the plurality of chips were transferred from the dicing sheet to the work handling sheet, and a laminate in which a plurality of chips were provided on the work handling sheet was obtained.

[0115] (1-2) Example 14 The release sheet was peeled off from the work handling sheet manufactured in Example 14, and the exposed surface thereby exposed was attached to one side of a silicon wafer (#2000, thickness: 350 μm). Subsequently, a dicing ring frame was attached to the peripheral portion of the exposed surface in the work handling sheet (a position that does not overlap with the silicon wafer). Furthermore, the work handling sheet was cut according to the outer diameter of the ring frame. Then, using a dicing device (manufactured by DISCO Corporation, product name "DFD6362"), the silicon wafer was diced into chips having a size of 300 μm × 300 μm. As a result, a laminate in which a plurality of chips were provided on the work handling sheet was obtained.

[0116] (2) Separation of chips by laser irradiation (separation process) In the laminate obtained in step (1) above, in which multiple chips are provided on a work handling sheet, laser light was irradiated onto the chips through the work handling sheet using a laser light irradiation device. This irradiation was performed using two types of laser light irradiation devices. For Examples 1 to 3 and 5 to 15 and Comparative Example 1, the first type of laser light irradiation device (indicated as "Type 1" in Table 1) was used, and for Example 4 and Comparative Example 2, the second type of laser light irradiation device (indicated as "Type 2" in Table 1) was used.

[0117] (2-1) Examples 1-3 and 5-15 and Comparative Example 1 Laser irradiation device (YAG third harmonic (wavelength 355 nm) with pulse width 20 ns and light intensity 700 mJ / cm²) 2 Using a work handling sheet, laser light was shone onto the chip. This irradiation was performed on a 270 μm × 270 μm area in the center of the chip. Other irradiation conditions were frequency: 30 kHz and irradiation dose: 50 μJ / shot. In addition, 100 chips (groups of 10 chips vertically × 10 chips horizontally) were selected from multiple chips and the irradiation was performed on them.

[0118] (2-2) Example 4 and Comparative Example 2 A laser beam was irradiated onto the chip through a work handling sheet using a laser beam irradiation device (manufactured by Keyence Corporation, product name "MD-U1000C"). The irradiation was performed by sequentially irradiating the center of the chip with a laser beam spot in a circular motion. The diameter of the laser beam spot was set to 25 μm, and the inner diameter of the ring resulting from the irradiation trajectory was set to 65 μm. Other irradiation conditions were frequency: 40 kHz, scan speed: 500 mm / s, and irradiation dose: 50 μJ / shot. Irradiation was performed on 100 chips (groups of 10 chips vertically x 10 chips horizontally) selected from a group of chips.

[0119] (3) Confirmation of blister and chip separation For the work handling sheets and tips subjected to the above irradiation, the presence or absence of blistering at the interface between the substrate and the interface ablation layer in the work handling sheet, and the presence or absence of detachment of the tip from the work handling sheet were checked, and the suitability for laser lift-off was evaluated based on the following criteria. The results are shown in Table 1. ◎...Blistering occurred at the location of all 100 chips, and all 100 chips detached. ○...The number of chips that developed blisters or detached was between 80 and 100. ×...The number of chips that developed blisters or detached was less than 80.

[0120] [Test Example 2] (Measurement of UV absorbance and UV transmittance) The release sheets were peeled off from the work handling sheets manufactured in the examples and comparative examples to expose the interface ablation layer. The ultraviolet absorbance and ultraviolet transmittance (%) of these work handling sheets were measured using a UV-Vis-Near Infrared Spectrophotometer (Shimadzu Corporation, product name "UV-3600") and its attached large sample chamber (Shimadzu Corporation, product name "MPC-3100"). This measurement was performed by using the integrating sphere built into the spectrophotometer, irradiating the surface with a wavelength of 355 nm light through a 20 nm slit width, towards the interface ablation layer side. The results are shown in Table 1.

[0121] [Test Example 3] (Evaluation of chip protection) In Test Example 1, all chips detached from the work handling sheet by laser irradiation were visually inspected at 100x magnification using a digital microscope (Keyence product name "VHX-7000") to check for the presence or absence of laser irradiation marks on the laser irradiation surface, and the chip protection was evaluated according to the following criteria. The results are shown in Table 1. ◎...No traces of laser light irradiation were found. ○...In cases where the traces of the incident laser irradiation pattern were unclear and the irradiation pattern could not be determined. ×...In the case of incident laser irradiation patterns, it was determined that the irradiation pattern could be clearly identified as a trace.

[0122] [Test Example 4] (Evaluation of chip visibility through tape) In Test Example 1, for multiple chips transferred onto a work handling sheet, we checked whether the surface of the chips could be visually seen through the work handling sheet and evaluated the visibility of the chips through the tape according to the following criteria. ○...It was visible. ×...Could not be seen.

[0123] Further details regarding the abbreviations and other terms listed in Table 1 are as follows: Tinuvin477: Tris[2,4,6-[2-{4-(octyl-2-methylethanol)oxy-2-hydroxyphenyl}]-1,3,5-triazine (hydroxyphenyltriazine-based UV absorber, manufactured by BASF, product name "Tinuvin477") Tinuvin479: 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine (hydroxyphenyltriazine-based UV absorber, manufactured by BASF, product name "Tinuvin479") Tinuvin326: 2-(5-chloro-2H-benzotriazol-2-yl)-6-(1,1-dimethylethyl)-4-methylphenol (benzotriazole-based UV absorber, manufactured by BASF, product name "Tinuvin326") CYASORB UV-24: 2,2'-dihydroxy-4-methoxybenzophenone (benzophenone-based UV absorber, manufactured by SOLVAY, product name "CYASORB UV-24") PET: Polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, product name "T-910 WM19", thickness: 50 μm) PO: Polyolefin film (a film with a thickness of 80 μm obtained by extruding a resin composition containing an ethylene-methacrylic acid copolymer (manufactured by Mitsui DuPont Polychemicals, product name "Nucrel NH903C") using a small T-die extruder (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name "Laboplastmill")).

[0124] [Table 1]

[0125] As is clear from Table 1, the work handling sheets manufactured in the examples exhibited excellent laser lift-off suitability. Furthermore, the work handling sheets manufactured in the examples showed a sufficiently reduced ultraviolet transmittance, as well as excellent chip protection and chip visibility through the tape. [Industrial applicability]

[0126] The work handling sheet of the present invention can be suitably used in the manufacture of displays and the like that which are equipped with micro-light-emitting diodes as pixels. [Explanation of symbols]

[0127] 1…Work Handling Sheet 11…Interfacial ablation layer 12...Base material 13…Reaction region 2,2'...Workpiece 3…Object 4… Laser light 5…Blister 6… Laser beam irradiation point

Claims

1. Substrate and The substrate is laminated on one side, capable of holding a small workpiece, and undergoes interface ablation by irradiation with laser light. A work handling sheet equipped with, The aforementioned substrate is a resin film, The interface ablation layer contains an ultraviolet absorber. A work handling sheet characterized by the following features.

2. The work handling sheet according to claim 1, characterized in that the ultraviolet absorber is an organic compound.

3. The work handling sheet according to claim 1 or 2, characterized in that the ultraviolet absorber is a compound having one or more heterocycles.

4. The UV absorber comprises at least one of a carbon ring and a heterocycle, All of the carbon rings and heterocycles in the UV absorber are monocycles. A work handling sheet according to any one of claims 1 to 3.

5. The work handling sheet according to any one of claims 1 to 4, characterized in that the ultraviolet absorber is a compound having a plurality of aromatic rings.

6. The work handling sheet according to any one of claims 1 to 5, characterized in that the ultraviolet absorber is at least one of tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine, 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, 2-(5-chloro-2H-benzotriazole-2-yl)-6-(1,1-dimethylethyl)-4-methylphenol and 2,2'-dihydroxy-4-methoxybenzophenone.

7. The work handling sheet according to any one of claims 1 to 6, characterized in that the content of the ultraviolet absorber in the interfacial ablation layer is 1% by mass or more and 75% by mass or less.

8. The work handling sheet is characterized in that the absorbance of light with a wavelength of 355 nm is 2.0 or higher, as described in any one of claims 1 to 7.

9. The work handling sheet according to any one of claims 1 to 8, characterized in that the transmittance of light with a wavelength of 355 nm is 1.0% or less.

10. The work handling sheet according to any one of claims 1 to 9, characterized in that the interfacial ablation layer is an adhesive layer.

11. The work handling sheet according to claim 10, characterized in that the adhesive constituting the adhesive layer is an acrylic adhesive.

12. The work handling sheet according to any one of claims 1 to 11, characterized in that the thickness of the interface ablation layer is 3 μm or more and 100 μm or less.

13. The work handling sheet according to any one of claims 1 to 12, characterized in that the thickness of the substrate is 10 μm or more and 500 μm or less.

14. The work handling sheet according to any one of claims 1 to 13, characterized in that the laser light has a wavelength in the ultraviolet region.

15. The work handling sheet according to any one of claims 1 to 14, characterized in that when interfacial ablation is caused in the interfacial ablation layer, a blister is formed at the location where the interfacial ablation occurs.

16. A work handling sheet according to any one of claims 1 to 15, characterized in that it is used to selectively separate any work piece from the interface ablation layer, which is held on the surface of the interface ablation layer opposite to the substrate, by interface ablation locally generated in the interface ablation layer.

17. The workpiece handling sheet according to claim 16, characterized in that the workpiece pieces are obtained by fragmenting a workpiece held on the surface opposite to the substrate in the interface ablation layer on that surface.

18. The workpiece handling sheet according to claim 16 or 17, characterized in that the workpiece is at least one selected from semiconductor components and semiconductor devices.

19. The workpiece handling sheet according to any one of claims 16 to 18, characterized in that the workpiece is a light-emitting diode selected from mini light-emitting diodes and micro light-emitting diodes.

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

21. The device manufacturing method according to claim 20, characterized in that, in the preparation step, the workpiece held on the surface opposite to the substrate in the interfacial ablation layer is fragmented on that surface to obtain the workpiece fragments.

22. The device manufacturing method according to claim 20 or 21, characterized in that the workpiece is at least one selected from semiconductor components and semiconductor devices.

23. A device manufacturing method according to any one of claims 20 to 22, characterized in that a light-emitting device comprising a plurality of light-emitting diodes is manufactured using light-emitting diodes selected from mini light-emitting diodes and micro light-emitting diodes as the workpiece.

24. The device manufacturing method according to claim 23, characterized in that the light-emitting device is a display.

Images