WO2022153745A1

WO2022153745A1 - Workpiece handling sheet and device manufacturing method

Info

Publication number: WO2022153745A1
Application number: PCT/JP2021/045507
Authority: WO
Inventors: 健太古野; 彰朗福元; 洋司若山; 征太郎山口
Original assignee: リンテック株式会社
Priority date: 2021-01-13
Filing date: 2021-12-10
Publication date: 2022-07-21
Also published as: TW202240759A

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

Work handling sheet and device manufacturing method

The present invention relates to a work handling sheet that can be used for handling small workpieces such as semiconductor parts and semiconductor devices, and a device manufacturing method using the work handling sheet, and in particular, a micro light emitting diode, a power device, and a MEMS. It relates to a work handling sheet that can be used for handling small pieces of work such as (Micro Electro Mechanical Systems), and a device manufacturing method using the work handling sheet.

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

At the time of the above mounting, it is necessary to accurately mount a plurality of micro light emitting diodes arranged on the supply board at a predetermined position on the wiring board. At this time, it is necessary to selectively mount a predetermined one from a plurality of micro light emitting diodes on the wiring board, or it is also necessary to mount a plurality of micro light emitting diodes at the same time.

From the viewpoint of performing such mounting well, the use of laser light irradiation is being considered. For example, after holding a plurality of micro light emitting diodes on a support via a predetermined layer, the layer is irradiated with laser light to cause ablation of the layer at the irradiated position, thereby supporting the layer. A method of mounting a micro light emitting diode separated from the body (laser lift-off) on a wiring substrate has been studied (Patent Document 1). Since the laser beam is excellent in directivity and convergence, it is easy to control the irradiation position, and selective placement can be performed satisfactorily.

Patent No. 6546278

However, further miniaturization of micro light emitting diodes and higher density mounting of micro light emitting diodes are being promoted, and in dealing with these, a large number of micro light emitting diodes are more efficiently used than conventional methods such as Patent Document 1. There is a need for a means capable of handling fine workpiece pieces such as micro light emitting diodes.

The present invention has been made in view of such an actual situation, and provides a work handling sheet capable of satisfactorily handling even a fine work piece, and a device manufacturing method using the work handling sheet. The purpose is.

In order to achieve the above object, firstly, the present invention comprises a base material and an interfacial ablation layer which is laminated on one side of the base material, can hold a small piece of work, and ablates the interface by irradiation with laser light. Provided is a work handling sheet comprising the above, wherein the interfacial ablation layer contains an ultraviolet absorber (Invention 1).

In the work handling sheet according to the above invention (Invention 1), since the interfacial ablation layer contains an ultraviolet absorber, the interfacial ablation is effectively performed when irradiated with laser light, thereby targeting small pieces of work as an object. Can be separated well towards.

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

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

In the above inventions (Inventions 1 to 3), the ultraviolet absorber has at least one carbon ring and a heterocycle, and all the carbon rings and the heterocycle contained in the ultraviolet absorber are monocyclic rings, respectively. It is preferable that there is (Invention 4).

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

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).

In the above inventions (Inventions 1 to 6), the work handling sheet preferably has an absorbance of light rays having a wavelength of 355 nm of 2.0 or more (Invention 7).

In the above inventions (Inventions 1 to 7), the work handling sheet preferably has a transmittance of light rays having a wavelength of 355 nm of 1.0% or less (Invention 8).

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

In the above invention (Invention 9), the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is preferably an acrylic pressure-sensitive adhesive (Invention 10).

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

In the above inventions (Inventions 1 to 11), when interfacial ablation is generated in the interfacial ablation layer, it is preferable that a blister is formed at the position where the interfacial ablation occurs (Invention 12).

In the above inventions (Inventions 1 to 12), among a plurality of work pieces held on a surface opposite to the base material in the interface ablation layer by the interface ablation locally generated in the interface ablation layer. It is preferable that any piece of the work piece of the above is used for selectively separating from the interfacial ablation layer (Invention 13).

In the above invention (Invention 13), the work piece is obtained by individualizing a work held on a surface of the interface ablation layer opposite to the base material on the surface. Is preferable (Invention 14).

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

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

Secondly, the present invention relates to a plurality of work handling sheets including a base material and an interfacial ablation layer containing an ultraviolet absorber laminated on one side of the base material on the surface on the interfacial ablation layer side. A preparatory step for preparing a laminate in which the work pieces are held, and an arrangement in which the laminate is arranged so that the surfaces on the work piece side of the laminate face each other with respect to an object that can accept the work pieces. Laser light is irradiated to the step and the position where at least one piece of the work piece is attached in the interfacial ablation layer in the laminated body to generate interfacial ablation at the irradiated position in the interfacial ablation layer. The device is manufactured by comprising a separation step of separating the work piece existing at the position where the interface ablation occurs from the work handling sheet and placing the work piece on the object. A method is provided (Invention 17).

In the above invention (Invention 17), in the preparatory step, the work piece is obtained by individualizing the work held on the surface of the interface ablation layer opposite to the base material on the surface. It is preferable (Invention 18).

In the above inventions (Inventions 17 and 18), it is preferable that the work piece is at least one selected from semiconductor parts and semiconductor devices (Invention 19).

In the above inventions (Inventions 17 to 19), it is preferable to manufacture a light emitting device including a plurality of the light emitting diodes by using a light emitting diode selected from a mini light emitting diode and a micro light emitting diode as the work piece (Invention 20). ..

In the above invention (invention 20), the light emitting device is preferably a display (invention 21).

The work handling sheet according to the present invention can handle even fine pieces of work satisfactorily, and according to the device manufacturing method according to the present invention, a device having excellent performance can be manufactured.

It is sectional drawing of the work handling sheet which concerns on one Embodiment of this invention. It is sectional drawing explaining the device manufacturing method using the work handling sheet which concerns on one Embodiment of this invention. It is sectional drawing explaining the state of a blister and a reaction region generated by irradiation of a laser beam.

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

In the work handling sheet 1 according to the present embodiment, the interface ablation layer 11 can hold a small piece of work. That is, the work handling sheet 1 according to the present embodiment can hold the work pieces laminated on the surface of the interface ablation layer 11 opposite to the base material 12 in that state.

Although the specific mode of the above holding is not limited, a preferable example is that the interface ablation layer 11 holds the work piece by exhibiting adhesiveness to the work piece. In this case, as will be described later, the interface ablation layer 11 preferably contains a pressure-sensitive adhesive as one of the components constituting the interface ablation layer 11, that is, a pressure-sensitive adhesive layer.

Further, the interfacial ablation layer 11 in the present embodiment is interfacial ablated by irradiation with laser light. That is, the interface ablation layer 11 locally ablates the interface in the region irradiated with the laser beam. The laser light is not particularly limited as long as it can cause interfacial ablation, and may be a laser light having any wavelength in the ultraviolet region, the visible light region, and the infrared region, and among them, the ultraviolet region. Laser light having the wavelength of is preferable.

In the present specification, the interfacial ablation means that a part of the components constituting the interfacial ablation layer 11 is evaporated or volatilized by the energy of the laser beam, and the gas generated thereby is the interface between the interfacial ablation layer 11 and the base material 12. It means that a gap (blister) is generated by accumulating in. In this case, the shape of the interface ablation layer 11 is changed by the blister, the work pieces are peeled off from the interface ablation layer 11, and the work pieces are separated.

Then, the interface ablation layer 11 in the present embodiment contains an ultraviolet absorber. The presence of the UV absorber in the interfacial ablation layer 11 improves the efficiency with which the interfacial ablation layer 11 receives energy from the laser beam. As a result, interfacial ablation is effectively generated, and the held work pieces can be well separated from the interfacial ablation layer 11. In particular, the amount of laser light irradiation required to cause sufficient separation of the work pieces can be reduced, the operating cost of the laser light irradiation device can be reduced, and only the target work pieces can be easily separated satisfactorily. As a result, the accuracy is improved, and further, damage to the device or the like due to excessive laser light irradiation can be prevented.

1. 1. Interface ablation layer The specific configuration and composition of the interface ablation layer 11 in the present embodiment has the property of being able to hold small pieces of work, having the property of interfacial ablation by irradiation with laser light, and containing an ultraviolet absorber. As long as it does, it is not particularly limited.

As described above, the interface ablation layer 11 preferably contains an adhesive as one of the constituents thereof, from the viewpoint that the property of being able to hold small pieces of work can be easily exhibited. When the interface ablation layer 11 contains a pressure-sensitive adhesive, the interface ablation layer 11 is preferably made of a pressure-sensitive composition containing an ultraviolet absorber.

(1) Ultraviolet absorber The type of ultraviolet absorber in the present embodiment is not particularly limited. The ultraviolet absorber in the present embodiment may be an organic compound or an inorganic compound, but is preferably an organic compound from the viewpoint of easily causing good interfacial ablation.

When the UV absorber is an organic compound, preferred examples of the UV absorber are hydroxyphenyltriazine-based UV absorbers, benzophenone-based UV absorbers, benzotriazole-based UV absorbers, benzoate-based UV absorbers, and benzooxadinone. UV absorbers, phenylsalicylate UV absorbers, cyanoacrylate UV absorbers, nickel complex salt UV absorbers, hydroquinone UV absorbers, salicylic acid UV absorbers, malonic acid ester UV absorbers, oxalic UV absorbers Examples include compounds such as absorbers. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Among the above-mentioned UV absorbers, hydroxyphenyltriazine-based UV absorbers and benzophenone-based UV absorbers have good absorbency at the third harmonic of YAG (355 nm) and are likely to cause good interfacial ablation. It is preferable to use at least one of an ultraviolet absorber and a benzotriazole-based ultraviolet absorber, and it is particularly preferable to use a hydroxyphenyltriazine-based ultraviolet absorber.

Examples of the hydroxyphenyltriazine-based ultraviolet absorber include 2- [4- (octyl-2-methylethanoate) oxy-2-hydroxyphenyl] -4,6- [bis (2,4-dimethylphenyl)] -1. , 3,5-Triazine, 2- [4- (2-Hydroxy-3-dodecyloxy-propyl) oxy-2-hydroxyphenyl] -4,6- [bis (2,4-dimethylphenyl) -1,3 5-Triazine, 2- [4- (2-hydroxy-3-tridecyloxy-propyl) 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, 2,4-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, tris [2,4,6- [2- {4- (octyl-2-methylethanoate) oxy-2-hydroxyphenyl}]] -1,3,5- Examples thereof include triazine. One of these may be used alone, or two or more thereof may be used in combination. Among these, 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 It is preferable to use at least one of (4-phenylphenyl) -1,3,5-triazine.

When the ultraviolet absorber is an organic compound, the ultraviolet absorber is preferably a compound having one or more heterocycles as a characteristic of its chemical structure. In this case, the number of heterocycles is preferably 4 or less, and particularly preferably 1.

Further, as another chemical structural feature, the ultraviolet absorber in the present embodiment has at least one carbon ring and a heterocycle, and all the carbon rings and the heterocycle contained in the ultraviolet absorber are monocyclic rings, respectively. Is also preferable.

As a further chemical structural feature, it is also preferable that the ultraviolet absorber in the present embodiment is a compound having a plurality of aromatic rings. In this case, the number of aromatic rings is preferably two or more. The number of aromatic rings is preferably 6 or less, and particularly preferably 3 or less.

In the above-mentioned chemical structural characteristics, each heterocycle preferably has at least one selected from nitrogen, oxygen, phosphorus, sulfur, silicon and selenium as an element other than carbon constituting them, particularly. , Nitrogen, oxygen, phosphorus and sulfur, preferably having at least one selected from. The number of atoms constituting the ring structure of the heterocycle is not particularly limited, and is, for example, 3 or more and 9 or less, and particularly preferably 5 or more and 6 or less. Specific examples of the preferred heterocycle include triazine, benzotriazole, thiophene, pyrrole, imidazole, pyridine, pyrazine and the like.

Further, in the above-mentioned chemical structural characteristics, preferable examples of the aromatic ring include benzene, naphthalene, anthracene, biphenyl, triphenyl and the like.

As an example of the ultraviolet absorber having the above-mentioned chemical structural characteristics, an ultraviolet absorber having the structure of the following formula (1) (Tris [2,4,6-[2- {4- (octyl-2-)) Methylethanoate) oxy-2-hydroxyphenyl}]-1,3,5-triazine).

The content of the ultraviolet absorber in the interface ablation layer 11 in the present embodiment is preferably 1% by mass or more, more preferably 2% by mass or more, and particularly preferably 3% by mass or more. Further, it is preferably 5% by mass or more. When the content of the ultraviolet absorber is 1% by mass or more, the interfacial ablation layer 11 efficiently absorbs the laser beam, thereby facilitating good interfacial ablation. Further, the content of the ultraviolet absorber in the interface ablation layer 11 in the present embodiment is preferably 75% by mass or less, more preferably 60% by mass or less, and particularly preferably 50% by mass or less. It is preferable, and more preferably 20% by mass or less. When the content of the ultraviolet absorber is 75% by mass or less, the viscosity of the material for forming the interface ablation layer 11 becomes appropriate, and it becomes easy to secure good film-forming property.

Further, when the interface ablation layer 11 in the present embodiment is formed from the adhesive composition described later, the ultraviolet absorber may be blended in this adhesive composition. In that case, the blending amount of the ultraviolet absorber in the adhesive composition is preferably 1% by mass or more, more preferably 2% by mass or more, and particularly preferably 3% by mass or more. Further, it is preferably 5% by mass or more. When the blending amount of the ultraviolet absorber is 1% by mass or more, the interfacial ablation layer 11 efficiently absorbs the laser light, thereby facilitating good interfacial ablation. Further, the blending amount of the ultraviolet absorber in 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 further. Is preferably 20% by mass or less. When the blending amount of the ultraviolet absorber is 75% by mass or less, the obtained pressure-sensitive adhesive can easily exhibit the desired adhesive strength.

(2) Adhesive As described above, the interface ablation layer 11 in the present embodiment may contain an adhesive in addition to the ultraviolet absorber. In this case, the interface ablation layer 11 is preferably formed from an adhesive composition containing an ultraviolet absorber.

The above-mentioned adhesive is not particularly limited as long as it can exhibit sufficient holding power (adhesive power) for an adherend such as a small piece of work. Examples of the above-mentioned adhesives include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, polyvinyl ether adhesives and the like. Among these, it is preferable to use an acrylic pressure-sensitive adhesive from the viewpoint of easily exerting a desired adhesive strength.

Examples of the acrylic pressure-sensitive adhesive include an acrylic pressure-sensitive adhesive using the acrylic polymer (A) as a 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. The weight average molecular weight (Mw) is preferably 2 million or less, and more preferably 1.5 million or less. When the weight average molecular weight of the acrylic polymer (A) is 10,000 or more, it becomes easy to increase the cohesive force of the obtained adhesive force, and it becomes easy to suppress the adhesive residue on the separated work pieces. Further, when the weight average molecular weight is 2 million or less, it becomes easy to obtain a stable coating film of the interface ablation layer. The weight average molecular weight (Mw) in the present specification is a standard polystyrene-equivalent value measured by a gel permeation chromatography method (GPC method).

The glass transition temperature (Tg) of the acrylic polymer (A) is preferably −70 ° C. or higher, and particularly preferably −60 ° C. or higher. The glass transition temperature (Tg) is preferably 20 ° C. or lower, and particularly preferably 10 ° C. or lower. When the glass transition temperature (Tg) of the acrylic polymer (A) is in the above range, it becomes easy to achieve a desired adhesive force while achieving a desired cohesive force.

The acrylic polymer (A) preferably contains at least a (meth) acrylic acid ester monomer as a constituent monomer, and a functional group capable of reacting with a functional group of the cross-linking agent (B) described later (hereinafter referred to as a functional group). , Also referred to as "reactive functional group").

Specific examples of the (meth) acrylic acid ester monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, and 2-ethylhexyl (. The number of carbon atoms of alkyl groups such as meta) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, and lauryl (meth) acrylate. Alkyl (meth) acrylate of 1 to 18; cycloalkyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate having a cycloalkyl group having about 1 to 18 carbon atoms. , Dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, (meth) acrylate having a cyclic skeleton such as imide (meth) acrylate; hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate , 2-Hydroxypropyl (meth) acrylate and other hydroxyl group-containing (meth) acrylates; glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, (3,4-epoxycyclohexyl) methyl (meth) acrylate, 3-epoxy Examples thereof include epoxy group-containing (meth) acrylates such as cyclo-2-hydroxypropyl (meth) acrylates.

Further, a monomer other than the (meth) acrylic acid ester monomer such as acrylic acid, methacrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide may be copolymerized. These may be used alone or in combination of two or more.

Since the acrylic polymer (A) contains a reactive functional group, it reacts with the functional group of the cross-linking agent (B) described later to form a three-dimensional network structure, and it becomes easy to enhance the cohesiveness of the interface ablation layer. .. Examples of the reactive functional group of the acrylic polymer (A) include a carboxyl group, an amino group, an epoxy group, a hydroxyl group and the like, and as described later, it is selectively selected from an organic polyvalent isocyanate compound preferably used as a cross-linking agent. It is preferable to contain a hydroxyl group because it easily reacts with.

The reactive functional group is an acrylic polymer (A) by forming an acrylic polymer (A) using the above-mentioned monomer having a reactive functional group such as a hydroxyl group-containing (meth) acrylate or acrylic acid. ) Can be introduced.

The ratio of the monomer having a reactive functional group (hereinafter, also referred to as a reactive group-containing monomer) to the total constituent monomers of the acrylic polymer (A) is preferably 0.3% by mass or more, and particularly 0. It is preferably 5% by mass or more. Further, the above ratio is preferably 40% by mass or less, and particularly preferably 20% by mass or less. By containing the reactive group-containing monomer in this range, it becomes easy to achieve the desired adhesive force while achieving the desired cohesive force.

Further, the acrylic polymer (A) preferably contains the above-mentioned alkyl (meth) acrylate as a constituent monomer, more preferably an alkyl (meth) acrylate having an alkyl group having 1 to 10 carbon atoms, and particularly preferably. Preferably contains an 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 the alkyl (meth) acrylate in the total constituent monomers of the acrylic polymer (A) may be 30% by mass or more. It is preferable, and it is particularly preferable that it is 35% by mass or more. Further, the above ratio is preferably 99% by mass or less, and particularly preferably 95% by mass or less. By containing the alkyl (meth) acrylate in this range, it becomes easy to achieve the desired adhesive force while achieving the desired cohesive force.

The use of the cross-linking agent (B) is preferable from the viewpoint that the storage elastic modulus of the interface ablation layer 11 can be easily adjusted to a desired range. As the cross-linking agent (B), a polyfunctional compound having reactivity with a reactive functional group 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, etc. Reactive phenolic resin and the like can be mentioned.

The blending amount of the cross-linking agent (B) is preferably 0.001 part by mass or more, particularly preferably 0.1 part by mass or more, and further preferably 0.1 part by mass or more with respect to 100 parts by mass of the acrylic polymer (A). Is preferably 0.2 parts by mass or more. The amount of the cross-linking agent (B) to be blended is preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less, and further 5 by mass with respect to 100 parts by mass of the acrylic polymer (A). It is preferably parts by mass or less.

The pressure-sensitive adhesive constituting the interface ablation layer 11 may be a pressure-sensitive adhesive having active energy ray curability. As such an active energy ray-curable pressure-sensitive adhesive, known ones can be used, and for example, those disclosed in International Publication No. 2018/084021 can be used.

In addition to the above-mentioned components, other additives may be added to the adhesive composition for forming the interfacial ablation layer 11. Examples of the additive include tackifiers, coloring materials such as dyes and pigments, flame retardants, fillers, antistatic agents and the like. The adhesive composition preferably does not contain a gas generating agent from the viewpoint that the separation of the work pieces is likely to occur satisfactorily. When a gas generating agent is used, gas may be generated in the entire interface ablation layer 11. In that case, it may be difficult to cause interfacial ablation only at the intended position and separate only the work pieces located there, and it may be difficult to separate the work pieces satisfactorily.

(3) Thickness of Interface Ablation Layer The thickness of the interface ablation layer 11 in the present embodiment is preferably 3 μm or more, particularly preferably 20 μm or more, and further preferably 25 μm or more. The thickness of the interface ablation layer 11 is preferably 100 μm or less, particularly preferably 50 μm or less, and further preferably 40 μm or less. When the thickness of the interface ablation layer 11 is within the above range, it becomes easy to achieve both the holding of the work pieces on the interface ablation layer 11 and the separation of the work pieces by the interface ablation.

2. Base material The base material 12 in the present embodiment is not particularly limited in composition and physical properties. From the viewpoint that the work handling sheet 1 easily exerts a desired function, the base material 12 is preferably made of a resin. When the base material 12 is composed of a resin, examples of the resin include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; both polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, and ethylene-norbornene. Polyethylene-based resins such as polymers and norbornene resins; ethylene-vinyl acetate copolymers; ethylene- (meth) acrylic acid copolymers, ethylene- (meth) methyl acrylate copolymers, and other ethylene- (meth) acrylics. Ethylene copolymer resin such as acid ester copolymer; polyvinyl chloride resin such as polyvinyl chloride and vinyl chloride copolymer; (meth) acrylic acid ester copolymer; polyurethane; polyimide; polystyrene; polycarbonate; fluororesin And so on. Further, the resin constituting the base material 12 may be a crosslinked resin of the above-mentioned resin or a modified resin such as the ionomer of the above-mentioned resin. Further, the base material 12 may be a single-layer film made of the above-mentioned resin, or may be a laminated film in which a plurality of the films are laminated. In this laminated film, the materials constituting each layer may be the same type or different types.

The surface of the base material 12 in the present embodiment may be surface-treated by an oxidation method, an unevenness method, or a primer treatment for the purpose of improving the adhesion to the interface ablation layer 11. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment, and examples of the unevenness method include sandblasting and sandblasting. Examples include a thermal spraying method.

The base material 12 in the present embodiment may contain various additives such as a colorant, a flame retardant, a plasticizer, an antistatic agent, a lubricant, and a filler. Further, when the interface ablation layer 11 contains a material that is cured by the active energy rays, it is preferable that the base material 12 has transparency to the active energy rays.

The method for producing the base material 12 in the present embodiment is not particularly limited as long as the base material 12 is produced from the resin. For example, it can be produced by molding a resin into a sheet by a melt extrusion method such as a T-die method or a round die method; a calendar method; a solution method such as a dry method or a wet method.

The thickness of the base material 12 in the present embodiment is preferably 10 μm or more, particularly preferably 30 μm or more, and further preferably 50 μm or more. 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, further preferably 150 μm or less, and preferably 100 μm or less. Is the most preferable. When the thickness of the base material 12 is within the above range, the work handling sheet 1 has rigidity and flexibility in a predetermined balance, and it becomes easy to perform good handling of the work small pieces.

3. 3. Peeling sheet When the interface ablation layer 11 contains an adhesive as one of its constituent components in the present embodiment, until the surface of the interface ablation layer 11 opposite to the base material 12 is attached to the work piece. , A release sheet may be laminated on the surface for the purpose of protecting the surface.

The configuration of the release sheet is arbitrary, and an example is one in which a plastic film is peeled off with a release agent or the like. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, a silicone type, a fluorine type, a long chain alkyl type or the like can be used, and among these, a silicone type which can obtain stable performance at a low cost is preferable.

The thickness of the release sheet is not particularly limited, and may be, for example, 20 μm or more and 250 μm or less.

4. Other Configurations In the work handling sheet 1 according to the present embodiment, an adhesive layer may be laminated on the surface of the interface ablation layer 11 opposite to the base material 12. In the sheet, a work piece is attached to the surface of the adhesive layer opposite to the interface ablation layer 11, and the adhesive layer is diced together with the work piece to laminate a piece of work in which individualized adhesive layers are laminated. Can be obtained. The chip is easily fixed to the object on which the work piece is mounted by the individualized adhesive layer. As the material constituting the adhesive layer described above, a material containing a thermoplastic resin and a low molecular weight thermosetting adhesive component, a material containing a B stage (semi-curable) thermosetting adhesive component, and the like are used. It is preferable to use it.

Further, in the work handling sheet 1 according to the present embodiment, the protective film forming layer may be laminated on the surface of the interface ablation layer 11 opposite to the base material 12. In such a sheet, a work is attached to the surface of the protective film forming layer opposite to the interface ablation layer 11, and the protective film forming layer is diced together with the work to obtain an individualized protective film forming layer. Stacked work pieces can be obtained. As the work, it is preferable to use a work having a circuit formed on one surface, and in this case, a protective film forming layer is usually laminated on a surface opposite to the surface on which the circuit is formed. By curing the individualized protective film forming layer at a predetermined timing, a protective film having sufficient durability can be formed on the work piece. The protective film forming layer is preferably made of an uncured curable adhesive.

5. Physical Properties of Work Handling Sheet The work handling sheet according to the present embodiment preferably has an absorbance of light rays having a wavelength of 355 nm of 2.0 or more, more preferably 2.5 or more, and particularly 3.0 or more. It is preferably present, and more preferably 3.5 or more. When the absorbance of light rays having a wavelength of 355 nm is 2.0 or more, it is possible to reduce the amount of ultraviolet rays reaching the work pieces when irradiated with laser light, effectively damaging the surface of the work pieces. It is possible to separate the work pieces while suppressing them. The upper limit of the absorbance is not particularly limited, and may be, for example, 6.0 or less. The details of the method for measuring the absorbance are as described in Test Examples described later.

In the work handling sheet according to the present embodiment, the transmittance of light rays having a wavelength of 355 nm is preferably 1.0% or less, more preferably 0.5% or less, and particularly 0.3% or less. It is preferably 0.1% or less. When the transmittance of light rays having a wavelength of 355 nm is 0.3% or less, it is possible to reduce the amount of ultraviolet rays reaching the work pieces when irradiated with laser light, which is effective in damaging the surface of the work pieces. It is possible to separate the work pieces while suppressing the work. The lower limit of the transmittance is not particularly limited, and may be, for example, 0.0001% or more, and particularly 0.0001% or more. The details of the method for measuring the transmittance are as described in Test Examples described later.

In the work handling sheet according to the present embodiment, the adhesive force of the silicon wafer to the mirror surface is preferably 10 mN / 25 mm or more, particularly preferably 100 mN / 25 mm or more, and further 200 mN / 25 mm or more. Is preferable. When the adhesive strength is 90 mN / 25 mm or more, it becomes easy to satisfactorily fix an adherend such as a work piece to the work handling sheet, and the handleability becomes excellent. The adhesive strength is preferably 30,000 mN / 25 mm or less, particularly preferably 15,000 mN / 25 mm or less, and further preferably 10,000 mN / 25 mm or less. When the adhesive strength is 30,000 mN / 25 mm or less, it becomes easier to better separate the work pieces by laser irradiation.

6. Manufacturing Method of Work Handling Sheet The manufacturing method of the work handling sheet 1 according to the present embodiment is not particularly limited. For example, the interface ablation layer 11 may be directly formed on the base material 12, or the interface ablation layer 11 may be transferred onto the base material 12 after the interface ablation layer 11 is formed on the process sheet. ..

When the interface ablation layer 11 contains an adhesive as one of the constituents thereof, the interface ablation layer 11 can be formed by a known method. For example, a tacky composition for forming the interfacial ablation layer 11 and, if desired, a coating solution further containing a solvent or dispersion medium are prepared. Then, the coating liquid is applied to one side of the base material or the peelable surface of the release sheet (hereinafter, may be referred to as "peeling surface"). Subsequently, the interface ablation layer 11 can be formed by drying the obtained coating film.

The above-mentioned coating liquid can be applied by a known method, for example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, or the like. The properties of the coating liquid are not particularly limited as long as it can be coated, and the coating liquid may contain a component for forming the interface ablation layer 11 as a solute or a dispersoid. be. Further, when the interface ablation layer 11 is formed on the release sheet, the release sheet may be peeled off as a process material, or the interface ablation layer 11 may be protected until it is attached to the adherend. ..

When the adhesive composition for forming the interface ablation layer 11 contains the above-mentioned cross-linking agent, by changing the above-mentioned drying conditions (temperature, time, etc.) or by separately providing a heat treatment. It is preferable to proceed the cross-linking reaction between the polymer component in the coating film and the cross-linking agent to form a cross-linked structure in the interface ablation layer 11 at a desired abundance density. Further, in order to allow the above-mentioned cross-linking reaction to proceed sufficiently, after the work handling sheet 1 is completed, it may be cured by allowing it to stand in an environment of, for example, 23 ° C. and a relative humidity of 50% for several days.

7. How to use the work handling sheet The work handling sheet 1 according to the present embodiment can be suitably used for handling small pieces of work. As described above, in the work handling sheet 1 according to the present embodiment, since the interface ablation layer 11 efficiently ablates the interface by irradiation with laser light, the small pieces of work held on the interface ablation layer 11 are high. It can be separated toward a predetermined position with accuracy.

As an example of the method of using the work handling sheet 1 according to the present embodiment, the work handling sheet 1 is held on the surface of the interface ablation layer 11 opposite to the base material 12 by the interface ablation locally generated in the interface ablation layer 11. A method of selectively separating any work piece from the plurality of work pieces from the interfacial ablation layer 11 can be mentioned.

In the above method of use, the plurality of work pieces held on the interface ablation layer 11 are the work (material of the work pieces) held on the surface of the interface ablation layer 11 opposite to the base material 12. It may be obtained by individualizing on the surface. That is, the work piece may be obtained by dicing the work on the interface ablation layer 11. Alternatively, the work piece may be one formed independently of the work handling sheet 1 according to the present embodiment and placed on the interface ablation layer 11.

When the work handling sheet 1 according to the present embodiment includes the above-mentioned adhesive layer and protective film forming layer, it is preferable to dice these layers and the work on the interface ablation layer 11. As a result, it is possible to obtain a work piece in which these layers are individualized and laminated.

Although the shape and size of the work pieces in the present embodiment are not particularly limited, the area of the work pieces in a plan view is preferably 10 μm ² or more, and particularly preferably 100 μm ² or more. Further, the work piece preferably has an area of 1 mm ² or less when viewed in a plan view, and particularly preferably 0.25 mm ² or less. Further, as for the dimensions of the work pieces, when the work pieces are rectangular, the minimum side of the work pieces is preferably 2 μm or more, particularly preferably 5 μm or more, and further preferably 10 μm or more. preferable. The minimum side is preferably 1 mm or less, and particularly preferably 0.5 mm or less. Specific examples of the dimensions of the rectangular workpiece pieces include 2 μm × 5 μm, 10 μm × 10 μm, 0.5 mm × 0.5 mm, 1 mm × 1 mm, and the like. The work handling sheet 1 according to the present embodiment can satisfactorily handle such fine work pieces, particularly even fine work pieces that are difficult to separate from the sheet by pushing up the needle. On the other hand, the work handling sheet 1 according to the present embodiment is relatively large, such as one having an area of more than 1 mm ² (for example, 1 mm ² to 2000 mm ² ) and one having a thickness of 1 to 10000 μm (for example, 10 to 1000 μm). It can handle small pieces of work of a size well.

Examples of small workpieces include semiconductor parts and semiconductor devices, and more specifically, micro light emitting diodes, power devices, MEMS (Micro Electro Mechanical Systems), and the like. Among these, the work piece is preferably a light emitting diode, and particularly preferably a light emitting diode selected from a mini light emitting diode and a micro light emitting diode. In recent years, the development of a device in which mini light emitting diodes and micro light emitting diodes are arranged at a high density has been studied, and in the manufacture of such a device, the present embodiment capable of handling these light emitting diodes with high accuracy. The work handling sheet 1 according to the above is very suitable.

Below, as a specific use example of the work handling sheet 1, a device manufacturing method will be described with reference to FIG. The device manufacturing method includes at least three steps of a preparation step (FIG. 2 (a)), a placement step (FIG. 2 (b)), and a separation step (FIGS. 2 (c) and (d)).

In the preparatory step, as shown in FIG. 2A, a laminated body in which a plurality of work pieces 2 are held on the surface of the work handling sheet 1 according to the present embodiment on the interface ablation layer 12 side is prepared. .. The laminated body may be prepared by placing a separately prepared work piece 2 on the work handling sheet 1, or a work held on the surface on the interface ablation layer 11 side is individually formed on the surface. It may be prepared by ablation (ie, dicing). The dicing can be performed by a known method.

The shape and size of the work piece 2 are not particularly limited as described above, and the preferred size is also as described above. As a specific example of the work piece 2, as described above, semiconductor parts, semiconductor devices, and the like can be mentioned, and in particular, light emitting diodes such as mini light emitting diodes and micro light emitting diodes can be mentioned.

In the subsequent arrangement step, as shown in FIG. 2B, the laminate is arranged so that the surfaces of the laminate 2 on the work fragment 2 side face each other with respect to the object 3 that can accept the workpiece 2. .. An example of the object 3 is appropriately determined according to the device to be manufactured, but when the work piece 2 is a light emitting diode, specific examples of the object 3 include a substrate, a sheet, a reel, and the like. In particular, a wiring board provided with wiring is preferably used.

After that, in the separation step, first, as shown in FIG. 2C, the laser beam is irradiated to the position of the interface ablation layer 11 in the laminated body to which at least one work piece 2 is attached. The irradiation may be performed simultaneously on a plurality of positions to which the work pieces 2 are attached, or may be sequentially performed on those positions. The irradiation conditions of the laser beam are not limited as long as it is possible to cause interfacial ablation. As a device for irradiation, a known device can be used.

By the above irradiation, as shown in FIG. 2D, interfacial ablation can be generated at the irradiated position in the interfacial ablation layer 11. Specifically, by irradiation with laser light, in the region proximal to the base material 12 in the interface ablation layer 11, the components constituting the region evaporate or volatilize to become the reaction region 13. Then, the gas generated by the evaporation or volatilization accumulates between the base material 11 and the reaction region 13, and the blister 5 is formed. Due to the formation of the blister 5, the interface ablation layer 11 is locally deformed at the position of the work piece 2', and the work piece 2'is separated so as to be peeled off from the interface ablation layer 11. As described above, the work piece 2'existing at the position where the interface ablation has occurred can be placed on the object 3.

The reaction region 13 and the blister 5 generated by the irradiation of the laser light usually remain even after the work piece 2'is separated. FIG. 3 shows how the work pieces 2 are separated by sequentially irradiating the laser beam, and in particular, the state after separation (two on the left), the state during separation (center), and the separation. The previous state (two on the right) is shown. As shown, the separated blister 5 is usually in a slightly deflated state as compared with the separated blister 5.

When the interface ablation layer 11 contains an active energy ray-curable pressure-sensitive adhesive as one of its constituent components, the interface ablation layer 11 may be cured by irradiation with the above-mentioned laser light. Then, the hardening may reduce the adhesive force of the interface ablation layer 11 to the work piece 2 and, in combination with the above-mentioned action by the interface ablation, may cause good separation of the work piece 2'. Alternatively, the interface ablation layer 11 may be irradiated with active energy rays different from the above-mentioned irradiation of laser light, thereby reducing the adhesive force to the work piece 2. Such activation energy ray irradiation may be performed before or after irradiation with laser light. Further, the activation energy ray irradiation may be performed locally on the interface ablation layer 11 or may be performed on the entire surface of the interface ablation layer 11. The irradiation conditions and the irradiation device for the above-mentioned active energy ray irradiation are not particularly limited, and known conditions and known devices can be used.

The device manufacturing method described above may include steps other than the preparation step, the placement step, and the separation step. For example, grind, die bonding, wire bonding, molding, inspection, transfer step, and the like may be performed at an arbitrary timing between the preparation step and the separation step.

According to the device manufacturing method described above, various devices can be manufactured by appropriately selecting the work piece 2 and the object 3 to be used. For example, when a light emitting diode selected from a mini light emitting diode and a micro light emitting diode is used as the work piece 2, a light emitting device including a plurality of such light emitting diodes can be manufactured, and more specifically, a display. Can be manufactured. In particular, it is possible to manufacture a display having a micro light emitting diode as a pixel and a display having a plurality of mini light emitting diodes as a backlight.

The embodiments described above are described for facilitating the understanding of the present invention, not for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

For example, another layer is laminated between the interface ablation layer 11 and the base material 12 in the work handling sheet 1 according to the present embodiment, or on the surface of the base material 12 opposite to the interface ablation layer 11. May be good. Specific examples of the other layer include an adhesive layer. In this case, the above-mentioned separation step or the like can be performed with the surface on the pressure-sensitive adhesive layer side attached to a support base (transparent substrate such as a glass plate).

The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is not particularly limited, but preferably one that is difficult to absorb the active energy ray and is difficult to block the active energy ray. In this case, when the laser beam is irradiated through the pressure-sensitive adhesive layer, the laser beam easily reaches the interface ablation layer 11, and good interface ablation is likely to occur. Specifically, as the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, it is preferable to use a pressure-sensitive adhesive having no active energy ray-curable component, and in particular, a pressure-sensitive adhesive containing no active energy ray-curable component may be used. preferable. By using a pressure-sensitive adhesive that does not have active energy ray curability, the pressure-sensitive adhesive layer does not cure even when irradiated with the laser beam, whereby the intention of the work handling sheet 1 from the transparent substrate 1 It is also possible to prevent peeling that does not occur. The thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably 5 to 50 μm, for example.

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope of the present invention is not limited to these Examples and the like.

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

100 parts by mass of the acrylic polymer obtained above (solid content equivalent, the same applies hereinafter) and 0.94 parts by mass of trimethylol propane-modified tolylene diisocyanate (manufactured by Toso Co., Ltd., trade name "Coronate L") as a cross-linking agent. And Tris as an ultraviolet absorber [2,4,6- [2- {4- (octyl-2-methylethanoate) oxy-2-hydroxyphenyl}]-1,3,5-triazine (hydroxyphenyltriazine) A coating solution of an adhesive composition was obtained by mixing 2.0 parts by mass of a UV absorber, product name "Tinuvin 477") manufactured by BASF, in a solvent.

(2) Formation of interfacial ablation layer (adhesive layer) A release sheet (manufactured by Lintec Corporation, product name "SP-PET38131") in which a silicone-based release agent layer is formed on one side of a 38 μm-thick polyethylene terephthalate film. The coating liquid of the adhesive composition obtained in the above step (1) was applied to the peeled surface, and the obtained coating film was dried by heating. As a result, a laminate obtained by laminating an interface ablation layer having a thickness of 30 μm, which is obtained by drying the coating film, and a release sheet.

(3) Preparation of Work Handling Sheet The surface of the laminate obtained in the above step (2) on the interface ablation layer side and the polyethylene terephthalate film as the base material (manufactured by Mitsubishi Chemical Corporation, product name "T-910 WM19", By laminating one side with a thickness of 50 μm), a work handling sheet with a release sheet attached was obtained.

Here, the above-mentioned weight average molecular weight (Mw) is a standard polystyrene-equivalent weight average molecular weight measured under the following conditions (GPC measurement) using gel permeation chromatography (GPC).
<Measurement conditions>
-Measuring device: HLC-8320 manufactured by Tosoh Corporation
-GPC column (passed in the following order): TSK gel superH-H manufactured by Tosoh Corporation
TSK gel superHM-H
TSK gel superH2000
-Measurement solvent: tetrahydrofuran-Measurement temperature: 40 ° C

[Examples 2 to 14 and Comparative Examples 1 to 2]
A work handling sheet was produced in the same manner as in Example 1 except that the content of the cross-linking agent and the type and content of the ultraviolet absorber were changed as shown in Table 1.

[Example 15]
As a base material, a resin composition containing an ethylene-methacrylic acid copolymer (manufactured by Mitsui DuPont Polychemical Co., Ltd., product name "Nucrel NH903C") is used as a small T-die extruder (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name "Lab"). Example 1 except that a base material (polyolefin-based base material) having a thickness of 80 μm obtained by extrusion molding with a plastic mill ”) is used and the content of the ultraviolet absorber is changed as shown in Table 1. A work handling sheet was manufactured in the same manner as above.

[Test Example 1] (Evaluation of laser lift-off suitability)
(1) Tip preparation on the work handling sheet (preparation process)
(1-1) Examples 1 to 13 and 15 and Comparative Examples 1 to 2.
An adhesive surface of a dicing sheet (manufactured by Lintec Corporation, product name "D-485H") was attached to one side of a silicon wafer (# 2000, thickness: 350 μm). Subsequently, a dicing ring frame was attached to the peripheral edge of the adhesive surface (position not overlapping the silicon wafer) of the dicing sheet. Further, the dicing sheet was cut according to the outer diameter of the ring frame. Then, a silicon wafer was diced into a chip having a size of 300 μm × 300 μm using a dicing apparatus (manufactured by Disco Corporation, product name “DFD6362”). Then, the dicing sheet was irradiated with ultraviolet rays (illuminance 230 mW / cm ² , light intensity 190 mJ / cm ² ). As a result, a laminated body in which a plurality of chips were provided on the dicing sheet was obtained.

Subsequently, the release sheet was peeled off from the work handling sheets produced in Examples and Comparative Examples, and the exposed exposed surface was bonded to the surface of the laminate obtained as described above in which a plurality of chips exist. .. Then, the dicing sheet was peeled off from the plurality of chips. As a result, a plurality of chips were transferred from the dicing sheet to the work handling sheet, and a laminated body in which the plurality of chips were provided on the work handling sheet was obtained.

(1-2) Example 14
The release sheet was peeled off from the work handling sheet produced in Example 14, and the exposed exposed surface was attached to one side of a silicon wafer (# 2000, thickness: 350 μm). Subsequently, a dicing ring frame was attached to the peripheral edge of the exposed surface of the work handling sheet (position not overlapping the silicon wafer). Further, the work handling sheet was cut according to the outer diameter of the ring frame. Then, a silicon wafer was diced into a chip having a size of 300 μm × 300 μm using a dicing apparatus (manufactured by Disco Corporation, product name “DFD6362”). As a result, a laminated body in which a plurality of chips were provided on the work handling sheet was obtained.

(2) Separation of chips by laser irradiation (separation step)
The laminate obtained in the above step (1), in which a plurality of chips are provided on the work handling sheet, was irradiated with laser light on the chips through the work handling sheet using a laser light irradiation device. .. The irradiation is performed using two types of laser light irradiation devices, and the first type of laser light irradiation device for Examples 1 to 3 and 5 to 15 and Comparative Example 1 (denoted as "Type 1" in Table 1). In Example 4 and Comparative Example 2, a second type of laser light irradiation device (denoted as “Type 2” in Table 1) was used.

(2-1) Examples 1 to 3 and 5 to 15 and Comparative Example 1
A laser beam irradiator (YAG third harmonic (wavelength 355 nm), pulse width 20 ns, light intensity 700 mJ / cm ² ) was used to irradiate the chip with laser light through the work handling sheet. The irradiation was performed on a region of 270 μm × 270 μm in the center of the chip. Other irradiation conditions were frequency: 30 kHz and irradiation amount: 50 μJ / shot. In addition, irradiation was performed by selecting 100 chips (a group of 10 vertical × 10 horizontal chips) from a plurality of chips.

(2-2) Example 4 and Comparative Example 2
The chip was irradiated with laser light through the work handling sheet using a laser light irradiation device (manufactured by KEYENCE, product name "MD-U1000C"). The irradiation was performed by sequentially irradiating the center of the chip with laser light spots in a circular motion. At this time, the diameter of the laser beam spot was set to 25 μm, and the inner diameter of the ring generated as the irradiation locus was set to 65 μm. Other irradiation conditions were frequency: 40 kHz, scan speed: 500 mm / s, and irradiation amount: 50 μJ / shot. Further, the irradiation was performed by selecting 100 chips (a group of 10 vertical × 10 horizontal chips) from a plurality of chips and performing the irradiation on them.

(3) Confirmation of separation of blister and insert Regarding the work handling sheet and chip that have been irradiated as described above, the presence or absence of blister at the interface between the base material and the interface ablation layer on the work handling sheet, and the presence or absence of blister from the work handling sheet. The presence or absence of detachment was confirmed, and the laser lift-off suitability was evaluated based on the following criteria. The results are shown in Table 1.
⊚ ... Blister was generated at the positions of all 100 chips, and all 100 chips were detached.
◯ ... The number of chips in which blisters were generated and detached was 80 or more and less than 100.
X ... The number of chips in which blisters were generated and detached was less than 80.

[Test Example 2] (Measurement of UV absorbance and UV transmittance)
The release sheet was peeled off from the work handling sheets produced in Examples and Comparative Examples to expose the interfacial ablation layer. For this work handling sheet, use an ultraviolet / visible / near-infrared spectrophotometer (manufactured by Shimadzu Corporation, product name "UV-3600") and an attached large sample chamber (manufactured by Shimadzu Corporation, product name "MPC-3100"). UV absorbance and UV transmittance (%) were measured using. The measurement was carried out by irradiating a light beam having a slit width of 20 nm and a wavelength of 355 nm toward the surface on the interface ablation layer side using an integrating sphere built in the spectrophotometer. The results are shown in Table 1.

[Test Example 3] (Evaluation of chip protection)
In Test Example 1, for all the chips detached from the work handling sheet by laser light irradiation, a digital microscope (manufactured by Keyence, product name "VHX-7000") was used to check the presence or absence of laser light irradiation marks on the laser light irradiation surface. It was visually confirmed at a magnification of 100 times, and the chip protection was evaluated according to the following criteria. The results are shown in Table 1.
◎… There was no trace of laser light irradiation.
○… It was judged that the trace was unclear with respect to the irradiation pattern of the incident laser and the irradiation pattern could not be determined. ×… It was judged that the irradiation pattern could be clearly identified as a trace with respect to the irradiation pattern of the incident laser.

[Test Example 4] (Evaluation of chip visibility through tape)
With respect to the plurality of chips transferred to the work handling sheet in Test Example 1, it was confirmed whether the surface of the chips could be visually visually recognized through the work handling sheet, and the chip visibility through the tape was evaluated according to the following criteria.
○… I was able to see it.
× ... I couldn't see it.

Details of the abbreviations and the like shown in Table 1 are as follows.
Tinuvin477: Tris [2,4,6-[2- {4- (octyl-2-methylethanoate) oxy-2-hydroxyphenyl}]] -1,3,5-triazine (hydroxyphenyltriazine UV absorber, Made by BASF, product name "Tinuvin 477")
Tinuvin 479: 2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl) -4,6-bis (4-phenylphenyl) -1,3,5-triazine (hydroxyphenyltriazine UV absorber, Made by BASF, product name "Tinuvin 479")
Tinuvin 326: 2- (5-chloro-2H-benzotriazole-2-yl) -6- (1,1-dimethylethyl) -4-methylphenol (benzotriazole UV absorber, manufactured by BASF, product name "Tinuvin 326"")
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-based film (resin composition containing ethylene-methacrylic acid copolymer (manufactured by Mitsui DuPont Polychemical Co., Ltd., product name "Nucrel NH903C"), small T-die extruder (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name) 80 μm thick film obtained by extrusion molding with “Laboplast Mill”)

As is clear from Table 1, the work handling sheet manufactured in the examples was excellent in laser lift-off suitability. Further, in the work handling sheet produced in the examples, the ultraviolet transmittance is sufficiently lowered, and the chip protection and the chip visibility through the tape are excellent.

The work handling sheet of the present invention can be suitably used for manufacturing a display or the like provided with a micro light emitting diode as a pixel.

1 ... Work handling sheet 11 ... Interfacial ablation layer 12 ... Base material 13 ... Reaction area 2, 2'... Work small pieces 3 ... Object 4 ... Laser light 5 ... Blister 6 ... Laser light irradiation point

Claims

With the base material
A work handling sheet laminated on one side of the base material, capable of holding small pieces of work, and provided with an interfacial ablation layer that ablates the interface by irradiation with laser light.
A work handling sheet in which the interfacial ablation layer contains an ultraviolet absorber.
The work handling sheet according to claim 1, wherein the ultraviolet absorber is an organic compound.
The work handling sheet according to claim 1 or 2, wherein the ultraviolet absorber is a compound having one or more heterocycles.
The ultraviolet absorber has at least one of a carbon ring and a heterocycle, and has
The work handling sheet according to any one of claims 1 to 3, wherein all the carbon rings and the heterocycles contained in the ultraviolet absorber are monocyclic rings.
The work handling sheet according to any one of claims 1 to 4, wherein the ultraviolet absorber is a compound having a plurality of aromatic rings.
The work handling sheet according to any one of claims 1 to 5, wherein the content of the ultraviolet absorber in the interface ablation layer is 1% by mass or more and 75% by mass or less.
The work handling sheet according to any one of claims 1 to 6, wherein the work handling sheet has an absorbance of light rays having a wavelength of 355 nm of 2.0 or more.
The work handling sheet according to any one of claims 1 to 7, wherein the work handling sheet has a transmittance of light rays having a wavelength of 355 nm of 1.0% or less.
The work handling sheet according to any one of claims 1 to 8, wherein the interface ablation layer is an adhesive layer.
The work handling sheet according to claim 9, wherein the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive.
The work handling sheet according to any one of claims 1 to 10, wherein the laser light has a wavelength in the ultraviolet region.
The work handling sheet according to any one of claims 1 to 11, wherein a blister is formed at a position where the interfacial ablation occurs when the interfacial ablation is generated in the interfacial ablation layer.
By the interfacial ablation locally generated in the interfacial ablation layer, any work piece among a plurality of work pieces held on the surface of the interfacial ablation layer opposite to the base material can be subjected to the interfacial ablation layer. The work handling sheet according to any one of claims 1 to 12, characterized in that it is used for selectively separating from.
13. The work piece is obtained by individualizing a work held on a surface of the interface ablation layer opposite to the base material on the surface. Described work handling sheet.
The work handling sheet according to claim 13 or 14, wherein the work piece is at least one selected from a semiconductor component and a semiconductor device.
The work handling sheet according to any one of claims 13 to 15, wherein the work piece is a light emitting diode selected from a mini light emitting diode and a micro light emitting diode.
A plurality of work pieces are held on the surface on the interface ablation layer side of the work handling sheet including the substrate and the interface ablation layer containing an ultraviolet absorber laminated on one side of the substrate. The preparatory process for preparing the laminate and
An arrangement step of arranging the laminated body so that the surfaces on the work piece side of the laminated body face each other with respect to an object that can accept the work small pieces.
By irradiating a position in the interfacial ablation layer of the laminated body to which at least one piece of the work is attached with laser light to cause interfacial ablation at the irradiated position in the interfacial ablation layer. A device manufacturing method comprising a separation step of separating the work piece existing at a position where the interface ablation occurs from the work handling sheet and placing the work piece on the object.
17. The preparatory step is characterized in that a work piece held on a surface opposite to the base material in the interface ablation layer is individualized on the surface to obtain the work piece. The device manufacturing method described in.
The device manufacturing method according to claim 17 or 18, wherein the work piece is at least one selected from a semiconductor component and a semiconductor device.
The invention according to any one of claims 17 to 19, wherein a light emitting device including a plurality of the light emitting diodes is manufactured by using a light emitting diode selected from a mini light emitting diode and a micro light emitting diode as the work piece. Device manufacturing method.
The device manufacturing method according to claim 20, wherein the light emitting device is a display.