TWI918831B - Manufacturing method of workpiece processing sheet and device - Google Patents

Abstract

This invention provides a workpiece processing sheet that can be effectively handled even with tiny working pieces, and a method for manufacturing an apparatus using this workpiece processing sheet. The solution is a workpiece processing sheet 1 comprising: a substrate 12, and an interface ablation layer 11 deposited on one side of the substrate 12 for holding the small working piece and subject to interface ablation by laser irradiation. The interface ablation layer 11 contains a photopolymerization initiator. The workpiece processing sheet 1 has an absorbance of 1.5 or higher for light with a wavelength of 355 nm.

Description

Method for manufacturing workpiece processing discs and devices

This invention relates to a workpiece processing chip that can be used to operate small workpieces such as semiconductor components and semiconductor devices, and a method for manufacturing an apparatus using the workpiece processing chip. In particular, it relates to a workpiece processing chip that can be used to operate small workpieces such as micro light emitting diodes, power devices, and MEMS (Micro Electro Mechanical Systems), and a method for manufacturing an apparatus using the workpiece processing chip.

In recent years, the development of displays using microlight-emitting diodes (LEDs) has been progressing. These displays consist of individual pixels composed of LEDs, each with its own independently controlled light emission. In the manufacturing process, generally, LEDs mounted on a feed substrate made of materials such as sapphire or glass must be assembled onto a wiring substrate with wiring provided.

During the above assembly, the plurality of micro-light-emitting diodes disposed on the supply substrate must be correctly placed at specific positions on the wiring substrate. At this time, a specific one must be selected from the plurality of micro-light-emitting diodes and placed on the wiring substrate, and the plurality of micro-light-emitting diodes must be placed simultaneously.

From the perspective of performing this type of assembly effectively, the use of laser light irradiation has been studied. For example, a method has been studied in which multiple micro-light-emitting diodes (LEDs) are maintained on a support through a specific layer, and then laser light is irradiated onto that layer, causing ablation at the irradiated location. This process separates the LEDs from the support (laser lift-off) and places them onto a wiring substrate (Patent 1). Laser light, due to its excellent directivity and convergence, allows for easy control of the irradiation position and enables selective placement. [Prior Art Documents] [Patent Documents]

Patent Document 1: Japanese Patent No. 6546278

[The problem the invention aims to solve]

However, as microluminescent diodes are further miniaturized and their assembly density increases, there is a growing demand for methods that can operate multiple microluminescent diodes and other tiny workpieces more efficiently than past methods such as those described in Patent 1.

This invention was made in view of this situation, and its purpose is to provide a workpiece processing plate that can be handled well even with tiny workpiece pieces, and a method for manufacturing an apparatus using this workpiece processing plate. [Means for solving the problem]

To achieve the above objectives, firstly, the present invention provides a workpiece processing sheet comprising: a substrate, and an interface ablation layer deposited on one side of the substrate for holding a small workpiece piece and for interface ablation by laser light irradiation, the interface ablation layer containing a photopolymerization initiator, and the absorbance of light with a wavelength of 355 nm of the workpiece processing sheet being 1.5 or more (Invention 1).

The workpiece processing sheet related to the above invention (Invention 1) contains a photopolymerization initiator in the interface ablation layer. When the light absorbance of light with a wavelength of 355nm is within the above range, interface ablation is effectively performed when irradiated with laser light, thereby allowing the small workpiece sheet to be well separated from the object.

In the above invention (Invention 1), the above photopolymerization initiator preferably has an absorption peak in the wavelength range of 200 nm to 400 nm (Invention 2).

In the above inventions (Inventions 1 and 2), it is preferable to use the above-mentioned interface ablation layer as the adhesive layer (Invention 3).

In the above invention (Invention 3), it is preferable that the adhesive constituting the adhesive layer is an active energy line hardening adhesive (Invention 4).

In the above inventions (Inventions 3 and 4), it is preferable that the adhesive constituting the adhesive layer is an acrylic adhesive (Invention 5).

Of the above inventions (Inventions 1 to 5), the laser light having a wavelength in the ultraviolet region is preferred (Invention 6).

In the above inventions (Inventions 1 to 6), when interface ablation occurs in the above interface ablation layer, it is preferable to form a blister at the location where interface ablation occurs (Invention 7).

In the above inventions (Inventions 1 to 7), it is preferable to selectively separate any one of the plurality of workpiece pieces on the opposite side of the substrate in the interface ablation layer by locally causing interface ablation in the interface ablation layer (Invention 8).

In the above invention (Invention 8), it is preferable that the workpiece piece is a workpiece that is maintained on the surface opposite to the substrate in the above interface ablation layer, and that it can be obtained by pieceping on that surface (Invention 9).

In the above inventions (Inventions 8 and 9), the workpiece piece is preferably selected from at least one of semiconductor components and semiconductor devices (Invention 10).

In the above inventions (Inventions 8-10), the small workpiece piece is preferably a light-emitting diode selected from mini light-emitting diodes and micro light-emitting diodes (Invention 11).

Second, the present invention provides a method for manufacturing an apparatus, comprising: preparing a substrate and an interface ablation layer containing a photopolymerization initiator deposited on one side of the substrate, a workpiece processing sheet having an absorbance of 1.5 or more for light at a wavelength of 355 nm, and maintaining a laminate consisting of a plurality of small workpiece pieces on the surface of the interface ablation layer; and for an object capable of accommodating the small workpiece pieces, facing the side of the small workpiece pieces in the laminate. The above-mentioned laminate is configured in a surface manner; laser light is irradiated at the position where at least one of the workpiece pieces is attached in the interface ablation layer of the above-mentioned laminate, and by causing interface ablation at the irradiated position in the interface ablation layer, the workpiece piece present at the position where interface ablation occurs is separated from the workpiece processing piece, and the workpiece piece is placed on the object (Invention 12).

In the above invention (Invention 12), it is preferable to obtain small pieces of the workpiece by individually processing the workpiece on the surface opposite to the substrate in the above preparation step on that surface.

In the above inventions (Inventions 12, 13), it is preferable that the workpiece piece is selected from at least one of semiconductor components and semiconductor devices (Invention 14).

In the above inventions (Inventions 12-14), it is preferable to use a light-emitting diode selected from miniature light-emitting diodes and micro light-emitting diodes as the workpiece piece to manufacture a light-emitting device having a plurality of the above-mentioned light-emitting diodes (Invention 15).

In the above invention (Invention 15), the light-emitting device is preferably used as a display (Invention 16). [Invention Benefits]

The workpiece processing plate of this invention can be operated well even for tiny workpiece pieces. Furthermore, according to the device manufacturing method of this invention, a device with excellent performance can be manufactured.

[The form in which the invention is implemented]

The embodiments of the present invention will now be described. Figure 1 shows a cross-sectional view of a workpiece processing sheet according to one embodiment. The workpiece processing sheet 1 shown in Figure 1 includes: a substrate 12, and an interface ablation layer 11 deposited on one side of the substrate 12.

In the workpiece processing sheet 1 of this embodiment, the interface ablation layer 11 can be used to maintain the workpiece piece. That is, the workpiece processing sheet 1 of this embodiment is a workpiece piece deposited on the surface opposite to the substrate 12 in the interface ablation layer 11, and can maintain its original state.

While the specific form of maintenance described above is not limited, as a preferred example, the interface ablation layer 11 is maintained by exhibiting adhesion to the workpiece piece. In this case, the interface ablation layer 11 is preferably composed of an adhesive, i.e., an adhesive layer.

Furthermore, in this embodiment, the interface ablation layer 11 is a type of interface ablation performed by laser light irradiation. That is, the interface ablation layer 11 is a type of interface ablation that occurs locally on the area irradiated by the aforementioned laser light. Moreover, the aforementioned laser light is not particularly limited as long as it can cause interface ablation, and can be any laser light with wavelengths in the ultraviolet, visible, and infrared regions, with laser light with wavelengths in the ultraviolet region being preferred.

In this specification, interface ablation refers to the evaporation or volatilization of a portion of the components constituting the interface ablation layer 11 using the energy of the aforementioned laser light. The resulting gas is trapped at the interface between the interface ablation layer 11 and the substrate 12, creating voids (bubbles). At this time, the shape of the interface ablation layer 11 changes due to the expansion of bubbles, and the workpiece piece peels off from the interface ablation layer 11, thus separating the workpiece piece.

Then, in this embodiment, the interface ablation layer 11 contains a photopolymerization initiator, and the absorbance of the workpiece processing sheet 1 with a wavelength of 355 nm is 1.5 or higher. Thus, by having a photopolymerization initiator in the interface ablation layer 11 and the workpiece processing sheet 1 exhibiting the aforementioned absorbance, the efficiency of the interface ablation layer 11 in receiving energy from laser light is improved. This allows for effective interface ablation, enabling the maintained workpiece piece to be well separated from the interface ablation layer 11. In particular, the amount of laser light required to fully separate small workpiece pieces is reduced, which can reduce the operating cost of the laser irradiation device. At the same time, the accuracy of easily separating the target small workpiece pieces is improved. Furthermore, damage to the device and other equipment caused by excessive laser light irradiation can be prevented.

From the viewpoint of further improving the efficiency of receiving energy from laser light, the aforementioned absorbance is preferably 2.0 or higher, more preferably 2.2 or higher, especially 2.5 or higher, and even more preferably 3.0 or higher. Furthermore, there is no particular limitation on the upper limit of the aforementioned absorbance; for example, it can be 6.0 or lower. In addition, details of the method for measuring the aforementioned absorbance are described in the following experimental examples.

1. Interface Ablation Layer The specific structure and composition of the interface ablation layer 11 in this embodiment are not particularly limited, as long as it can be used to maintain the workpiece piece, has the property of performing interface ablation by laser irradiation, contains a photopolymerization initiator, and can achieve the aforementioned absorbance as the workpiece processing piece 1.

From the viewpoint of easily and effectively utilizing the properties that can be used to maintain small pieces of workpieces, the interface ablation layer 11 preferably 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 formed of an adhesive composition containing a photopolymerization initiator.

(1) Photopolymerization Initiator The type of photopolymerization initiator in this embodiment is not particularly limited. Examples of preferred photopolymerization initiators include at least one of 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholinyl-phenyl)butane-1-one, acetone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl],1-(0-acetoxime), 1,2-octanedione, 1-[4-(phenylthio)phenyl],2-(ortho-benzoxime), 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropane-1-one.

In addition to the aforementioned photopolymerization initiators, other photopolymerization initiators can be used in conjunction. Examples of photopolymerization initiators that can be used in conjunction include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-hydroxycyclohexylphenyl ketone, and 4-(2-hydroxyethoxy)phenyl-2-(hydroxyacetophenone). Examples of benzophenones include: 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxymethylacetone, benzophenone, p-phenyl diphenyl ketone, 4,4'-diethylamino diphenyl ketone, dichloro diphenyl ketone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-trimethylbutylanthraquinone, 2-aminoanthraquinone, 2-methylthiatonone, 2-ethylthiatonone, 2-chlorothiatonone, 2,4-dimethylthiatonone, 2,4-diethylthiatonone, benzil dimethyl ketal, acetobenzo dimethyl ketal, p-dimethylamino benzoate, oligomeric [2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone], and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

In this embodiment, the photopolymerization initiator preferably has an absorption peak in the wavelength range of 200 nm to 400 nm. This allows the interface ablation layer 11 to efficiently absorb laser light, thereby facilitating effective interface ablation. From this perspective, the lower limit of the aforementioned range is particularly preferably 300 nm or higher, and more preferably 330 nm or higher. Furthermore, the upper limit of the aforementioned range is particularly preferably 380 nm or lower, and more preferably 370 nm or lower.

Furthermore, the aforementioned absorption peak can be specified using the following method. First, the photopolymerization initiator is dissolved in methanol or acetonitrile as a solvent to prepare a test solution with a concentration of 0.01% by mass. Next, the absorbance of this test solution is measured using a spectrophotometer (e.g., Shimadzu Corporation, "UV-3600") to obtain an absorption spectrum. Then, from the obtained absorption spectrum, the wavelength range of the absorption peak (nm) can be specified.

Furthermore, the photopolymerization initiator in this embodiment preferably has an absorbance of 0.5 or higher at a wavelength of 355 nm in a solution with a concentration of 0.01% by mass, particularly 0.75 or higher, and even more preferably 1.0 or higher. With an absorbance of 0.5 or higher, the interfacial ablation layer 11 efficiently absorbs laser light, thereby facilitating effective interfacial ablation. While the upper limit of the absorbance is not particularly limited, it can, for example, be 4.0 or lower.

Furthermore, the absorbance mentioned above is the absorbance in the wavelength range of 200 to 500 nm in a methanol solution with a concentration of 0.01% by mass of the photopolymerization initiator (when the photopolymerization initiator is insoluble in methanol, it is an acetonitrile solution), measured using a UV-Vis-NIR spectrophotometer (manufactured by Shimadzu Corporation, product name "UV-3600", 10 mm optical path).

In this embodiment, the content of the photopolymerization initiator in the interface ablation layer 11 is preferably 1.8% by mass or more, particularly 3.0% by mass or more, and even more preferably 5.0% by mass or more. By having a photopolymerization initiator content of 1.8% by mass or more, the interface ablation layer 11 efficiently absorbs laser light, thereby facilitating good interface ablation. Furthermore, in this embodiment, the content of the photopolymerization initiator in the interface ablation layer 11 is preferably 40.0% by mass or less, particularly 30.0% by mass or less, and even more preferably 25.0% by mass or less. By using a photopolymerization initiator content of 40.0% by mass or less, the viscosity of the material used to form the interfacial ablation layer 11 becomes suitable, making it easy to ensure good film-forming properties.

Furthermore, when the interfacial ablation layer 11 in this embodiment is formed from the following adhesive composition, a photopolymerization initiator can also be incorporated into this adhesive composition. In particular, when the photopolymerization initiator is incorporated into the adhesive composition along with the following active energy line-curing polymer (A), the amount of photopolymerization initiator in the adhesive composition is preferably 1.8 parts by mass or more, especially 3.0 parts by mass or more, and further preferably 5.0 parts by mass or more, relative to 100 parts by mass of the following active energy line-curing polymer (A). With a photopolymerization initiator amount of 1.8 parts by mass or more, the interfacial ablation layer 11 efficiently absorbs laser light, thereby facilitating good interfacial ablation. Furthermore, the amount of photopolymerization initiator in the aforementioned adhesive composition is preferably 40.0 parts by weight or less, especially 30.0 parts by weight or less, and even more preferably 25.0 parts by weight or less, relative to 100 parts by weight of the active energy line curing polymer (A). By using 40.0 parts by weight or less of photopolymerization initiator, the resulting adhesive becomes one that easily exhibits the desired adhesive force.

(2) Adhesive As mentioned above, the interfacial ablation layer 11 in this embodiment, along with the photopolymerization initiator, may also contain an adhesive. In this case, it is preferable that the interfacial ablation layer 11 is formed from an adhesive composition containing a photopolymerization initiator.

As for the aforementioned adhesives, there are no particular limitations as long as they can exert sufficient holding force (adhesive force) on the adhered material, such as small pieces 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 from the viewpoint of easily achieving the desired adhesive force.

Furthermore, while the aforementioned adhesive may be an adhesive without active energy line curing properties, it is preferable to use an adhesive with active energy line curing properties (hereinafter, sometimes referred to as an "active energy line curing adhesive"). When the interface ablation layer 11 is composed of an active energy line curing adhesive, the interface ablation layer 11 is hardened by irradiation with active energy lines, which can easily reduce the adhesion of the workpiece treatment sheet 1 to the adhered object.

In particular, by reducing adhesion through irradiation with active energy lines, and in conjunction with the aforementioned interface ablation, it becomes easier to separate the workpiece piece from the workpiece processing sheet 1. In other words, by reducing adhesion through irradiation with active energy lines before or simultaneously with the aforementioned interface ablation, the separation of the workpiece piece from the workpiece processing sheet 1 associated with this embodiment can be reliably achieved. Furthermore, the amount of laser light required for sufficient separation of the workpiece piece can be further reduced.

As the aforementioned active energy line curable adhesive, it may be a polymer with active energy line curability as the main component, or it may be a mixture of an active energy line non-curable polymer (polymer without active energy line curability) and a monomer and/or oligomer having at least one active energy line curable group as the main component. Furthermore, the active energy line curable adhesive may be a mixture of a polymer with active energy line curability and a monomer and/or oligomer having at least one active energy line curable group.

The aforementioned polymer with active energy line hardening properties is preferably a (meth)acrylate (co)polymer (A) (hereinafter sometimes referred to as "active energy line hardening polymer (A)") in which energy line hardening functional groups (active energy line hardening groups) are introduced into the side chains. This active energy line hardening polymer (A) is preferably obtained by reacting an acrylic copolymer (a1) having functionalized monomer units with unsaturated groups (a2) having functional groups bonded to these functional groups. Furthermore, in this specification, the term (meth)acrylate refers to both acrylate and methacrylate. Other similar terms are also the same. Moreover, "polymer" also includes the concept of "copolymer".

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

As a constituent unit of acrylic copolymer (a1), the monomer containing functional groups is preferably a monomer with polymerizable double bonds in the molecule, and functional groups such as hydroxyl, carboxyl, amino, substituted amino, epoxy, etc.

Examples of hydroxyl-containing monomers include, for example, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, etc., which can be used alone or in combination of two or more.

Examples of carboxyl-containing monomers include, for instance, vinyl unsaturated carboxylic acids such as acrylic acid, methacrylic acid, butenoic acid, maleic acid, itaconic acid, and leuconic acid. These can be used alone or in combination of two or more.

Examples of monomers containing an amino group or a substituted amino group include, for example, (meth)acrylate aminoethyl ester and (meth)acrylate n-butylaminoethyl ester. These can be used alone or in combination of two or more.

As a (meth)acrylate monomer constituting an acrylic copolymer (a1), in addition to alkyl (meth)acrylates with 1 to 20 carbon atoms in the alkyl group, monomers having an intramolecular alicyclic structure (monomers containing an alicyclic structure) are preferably also used.

As alkyl methacrylates, especially alkyl methacrylates with 1 to 18 carbon atoms, it is preferable to use, for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, etc. These can be used alone or in combination of two or more.

As monomers containing an alicyclic structure, preferably include, for example, cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, tetraalkyl (meth)acrylate, isocamphenyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyl oxyethyl (meth)acrylate. These can be used alone or in combination of two or more.

The acrylic copolymer (a1) contains a proportion of constituent units derived from the aforementioned functionalized monomers, preferably 1% by mass or more, particularly 5% by mass or more, and even more than 10% by mass. Furthermore, the acrylic copolymer (a1) contains a proportion of constituent units derived from the aforementioned functionalized monomers, preferably 35% by mass or less, particularly 30% by mass or less, and even more than 25% by mass or less.

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

Acrylic copolymers (a1) can be obtained by copolymerizing the functionalized monomers as described above with (meth)acrylate monomers or their derivatives using conventional methods. However, dimethacrylamide, vinyl formate, vinyl acetate, styrene, and other monomers other than these can also be copolymerized.

By reacting the acrylic copolymer (a1) having a functionalized monomer unit with a compound (a2) having an unsaturated group bonded thereto, an active energy line hardening polymer (A) can be obtained.

The functional groups of the compound (a2) containing unsaturated groups can be appropriately selected to correspond to the types of functional groups of the monomer units containing functional groups in the acrylic copolymer (a1). For example, when the functional group of the acrylic copolymer (a1) is hydroxyl, amino, or substituted amino, isocyanate or epoxy groups are preferred as functional groups in the compound (a2) containing unsaturated groups. When the functional group of the acrylic copolymer (a1) is epoxy, amino, carboxyl, or aziridinyl groups are preferred as functional groups in the compound (a2) containing unsaturated groups.

Furthermore, among the aforementioned compounds (a2) containing unsaturated groups, it is preferable that each molecule contains at least one energy-line polymerizable carbon-carbon double bond, more preferably 1 to 6, and even more preferably 1 to 4. Specific examples of such compounds (a2) containing unsaturated groups include, for instance, 2-methacryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1,1-(bisacryloyloxymethyl)ethyl isocyanate; diisocyanate compounds or polyisocyanate compounds, and the reaction of these compounds with hydroxyethyl (meth)acrylate. Acrylic monoisocyanate compounds obtained; diisocyanate compounds or polyisocyanate compounds, acrylic monoisocyanate compounds obtained by reaction with polyol compounds, and hydroxyethyl (meth)acrylate; glycidyl (meth)acrylate; (meth)acrylic acid, 2-(1-aziridinyl)ethyl (meth)acrylate, 2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline, etc.

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

In the reaction of an acrylic copolymer (a1) with a compound (a2) containing unsaturated groups, the reaction temperature, pressure, solvent, time, presence or absence of a catalyst, and type of catalyst can be appropriately selected according to the combination of functional groups possessed by the acrylic copolymer (a1) and the compound (a2) containing unsaturated groups. In this way, the functional groups present in the acrylic copolymer (a1) react with the functional groups in the compound (a2) containing unsaturated groups, introducing unsaturated groups into the side chains of the acrylic copolymer (a1), thus obtaining an active energy line-curing polymer (A).

The weight-average molecular weight (Mw) of the obtained active energy line-curing polymer (A) is preferably 10,000 or higher, especially 50,000 or higher, and further preferably 100,000 or higher. Furthermore, the weight-average molecular weight (Mw) is preferably 3 million or lower, especially 2 million or lower, and further preferably 1.5 million or lower. Moreover, the weight-average molecular weight (Mw) in this specification is a converted value for standard polystyrene determined by gel osmosis chromatography (GPC).

Even when the active energy line curing adhesive uses a polymer with active energy line curing properties, such as an active energy line curing polymer (A), as the main component, the active energy line curing adhesive may further contain energy line curing monomers and/or oligomers (B).

As monomers and/or oligomers (B) that are active energy line hardening agents, for example, polyols and esters of (meth)acrylic acid can be used.

Examples of related active energy line hardening monomers and/or oligomers (B) include, for example, monofunctional acrylates such as cyclohexyl methacrylate and isoborneol methacrylate; polyfunctional acrylates such as trihydroxypropane tri(meth)acrylate, neopentyltetra(meth)acrylate, neopentyltetra(meth)acrylate, dinepentyltetra(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, dihydroxymethyltricyclodecane di(meth)acrylate, polyester oligo(meth)acrylate, polyurethane oligo(meth)acrylate, etc.

When formulating the active energy line-curing polymer (A) and the active energy line-curing monomer and/or oligomer (B), the content of the active energy line-curing monomer and/or oligomer (B) in the active energy line-curing adhesive is preferably more than 0 parts by weight relative to 100 parts by weight of the active energy line-curing polymer (A), and especially more than 60 parts by weight. Furthermore, this content is preferably 250 parts by weight or less relative to 100 parts by weight of the active energy line-curing polymer (A), and especially less than 200 parts by weight.

Next, regarding the active energy line curable adhesive, the case where the main component is a mixture of an active energy line non-curable polymer component and a monomer and/or oligomer having at least one active energy line curable group will be explained below.

As a non-hardening polymer component for active energy lines, for example, the same component as the acrylic copolymer (a1) described above can be used.

The monomer and/or oligomer having at least one active energy line curing group can be the same as component (B) described above. The mixing ratio of the active energy line non-curing polymer component to the monomer and/or oligomer having at least one active energy line curing group is preferably 1 part by weight or more, particularly 60 parts by weight or more, relative to 100 parts by weight of the active energy line non-curing polymer component. Furthermore, this mixing ratio is preferably 200 parts by weight or less, particularly 160 parts by weight or less, relative to 100 parts by weight of the active energy line non-curing polymer component.

(3) Other Components Other suitable components may also be incorporated into the above adhesive composition. Examples of other components include, for instance, the non-hardening polymer or oligomer component of the active energy line (D), crosslinking agents (E), etc.

Examples of non-curing polymer or oligomer components (D) for active energy lines include, for example, polyacrylates, polyesters, polyurethanes, polycarbonates, and polyolefins, preferably polymers or oligomers with a weight average molecular weight (Mw) of 30 million to 2.5 million. By incorporating this component (D) into energy line curing adhesives, the adhesion and peelability before curing, the strength after curing, the adhesion to other layers, and the storage stability can be improved. The amount of this component (D) is not particularly limited, but it is appropriate to determine a range of more than 0 parts by weight and less than 50 parts by weight relative to 100 parts by weight of the energy line curing copolymer (A).

From the viewpoint of easily adjusting the storage modulus of the interfacial ablation layer 11 to the desired range, it is preferable to use a crosslinking agent (E). As the crosslinking agent (E), a multifunctional compound reactive with the functional groups of active energy line hardening copolymers (A) can be used. Examples of such multifunctional compounds include isocyanate compounds, epoxide 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.

The amount of crosslinking agent (E) is preferably 0.001 parts by weight or more, especially 0.1 parts by weight or more, and further preferably 0.2 parts by weight or more, relative to 100 parts by weight of the active energy line hardening copolymer (A). Furthermore, the amount of crosslinking agent (E) is preferably 20 parts by weight or less, especially 10 parts by weight or less, and further preferably 5 parts by weight or less, relative to 100 parts by weight of the active energy line hardening copolymer (A).

Furthermore, other components that can be incorporated into the aforementioned adhesive composition include tackifiers, coloring materials such as dyes and pigments, flame retardants, fillers, and antistatic agents. Moreover, from the viewpoint of facilitating the separation of small workpiece pieces, the aforementioned adhesive composition is preferably free of gas generators. When a gas generator is used, gas is generated throughout the entire interface ablation layer 11. In this case, it is difficult to cause interface ablation only at the desired location, and it is difficult to separate only the small workpiece piece located at that location; thus, the separation of the small workpiece piece cannot proceed effectively.

(4) Thickness of the Interface Ablation Layer In this embodiment, the thickness of the interface ablation layer 11 is preferably 3 μm or more, particularly 20 μm or more, and even more than 25 μm. Furthermore, the thickness of the interface ablation layer 11 is preferably 100 μm or less, particularly 50 μm or less, and even more preferably 40 μm or less. By having the thickness of the interface ablation layer 11 within the above range, it becomes easier to balance the maintenance of the workpiece pieces on the interface ablation layer 11 and the separation of the workpiece pieces through interface ablation.

2. Substrate The composition and physical properties of the substrate 12 in this embodiment are not particularly limited. From the viewpoint of easily performing the desired functions of the workpiece processing sheet 1, the substrate 12 is preferably made of resin. When the substrate 12 is composed of resin, examples of such resins include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resins such as polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, ethylene-norbornene copolymers, and norbornene resins; ethylene-vinyl acetate copolymers; ethylene-(meth)acrylate copolymers, ethylene-(meth)acrylate copolymers, and other ethylene-(meth)acrylate copolymers; polyvinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers; (meth)acrylate copolymers; polyurethane; polyimide; polystyrene; polycarbonate; and fluororesins. Furthermore, the resin constituting the substrate 12 can be a crosslinked resin or a modified ionomer of the resin. Additionally, the substrate 12 can be a monolayer film formed from the resin, or a laminated film formed by stacking multiple layers of the resin. In this laminated film, the materials constituting each layer can be the same or different.

To improve the adhesion of the interface ablation layer 11, surface treatments such as oxidation and texturing, or primer treatments, can be applied to the surface of the substrate 12 in this embodiment. Examples of oxidation methods include corona discharge treatment, plasma discharge treatment, wet chromate treatment, flame treatment, hot air treatment, ozone treatment, and ultraviolet irradiation treatment. Examples of texturing methods include sandblasting and melt-blowing.

The substrate 12 in this embodiment may also contain various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, and fillers. Furthermore, when the interface etch layer 11 contains a material that is hardened by active energy lines, it is preferable that the substrate 12 is permeable to the active energy lines.

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

In this embodiment, the thickness of the substrate 12 is preferably 10 μm or more, especially 30 μm or more, and further preferably 50 μm or more. Furthermore, the thickness of the substrate 12 is preferably 500 μm or less, more preferably 300 μm or less, especially 200 μm or less, further preferably 150 μm or less, and most preferably 100 μm or less. By using the thickness of the substrate 12 within the above-mentioned range, the workpiece processing sheet 1 achieves a specific balance between rigidity and flexibility, thus becoming a good material for processing small workpiece pieces.

3. Peeling In this embodiment, when the interface ablation layer 11 contains an adhesive as one of its components, the layer can be peeled off on the surface of the interface ablation layer 11 opposite to the substrate 12 until the workpiece piece is attached, with the aim of protecting that surface.

The composition of the aforementioned release sheet can be arbitrary; for example, it can be a plastic film that has undergone a release treatment using a release agent. Specific examples of such plastic films include polyester films made of polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, as well as polyolefin films made of polypropylene and polyethylene. As the aforementioned release agent, silicone-based, fluorine-based, and long-chain alkyl-based agents can be used; among these, silicone-based agents, which are inexpensive and offer stable performance, are preferred.

There are no particular limitations on the thickness of the above-mentioned peeling sheet; for example, it can be above 20μm and below 250μm.

4. Other Compositions The workpiece processing sheet 1 of this embodiment may also have an adhesive layer on the area opposite to the substrate 12 in the interface etched layer 11. By attaching a workpiece to the surface of the adhesive layer opposite to the interface etched layer 11 and cutting the workpiece along with the adhesive layer, a small workpiece piece with a laminated adhesive layer can be obtained. This laminated adhesive layer makes it easier to fix the chip to an object on which the small workpiece piece is mounted. As the material constituting the adhesive layer, it is preferable to use materials containing thermoplastic resin and low molecular weight thermosetting adhesive components, or materials containing B-stage (semi-cured) thermosetting adhesive components.

Furthermore, in the workpiece processing sheet 1 of this embodiment, a protective film forming layer can also be deposited on the surface of the interface ablation layer 11 opposite to the substrate 12. By attaching the surface of the protective film forming layer opposite to the interface ablation layer 11 to a workpiece and cutting the workpiece along with the protective film forming layer, a small workpiece piece with a sheet-like protective film forming layer can be obtained. It is preferable to use this workpiece where a circuit is formed on one side; in this case, a protective film forming layer is usually deposited on the surface opposite to the side with the circuit. By hardening the sheet-like protective film forming layer at a specific time, a sufficiently durable protective film can be formed on the small workpiece piece. The protective film layer is preferably formed by an uncured curable adhesive.

5. Physical Properties of the Workpiece Processing Sheet The workpiece processing sheet 1 of this embodiment preferably has an adhesion force of 10 mN/25 mm or more to the mirror surface of a silicon wafer, particularly 100 mN/25 mm or more, and even more than 200 mN/25 mm. With an adhesion force of 10 mN/25 mm or more, it is easy to firmly fix the workpiece piece or similar attachment onto the workpiece processing sheet 1, resulting in excellent operability. Furthermore, the adhesion force is preferably 30,000 mN/25 mm or less, particularly 15,000 mN/25 mm or less, and even more preferably 10,000 mN/25 mm or less. With an adhesion force of 30,000 mN/25 mm or less, it is easy to effectively separate the workpiece piece by laser irradiation.

Furthermore, when the interface ablation layer 11 in this embodiment is an adhesive layer composed of the aforementioned active energy line hardening adhesive, the adhesion after ultraviolet irradiation is preferably such that it meets the following conditions. In other words, when the side of the interface ablation layer 11 opposite to the substrate 12 is attached to the mirror surface of the silicon wafer, and the interface ablation layer 11 is irradiated with ultraviolet light using a high-pressure mercury lamp to harden it, the adhesion to the mirror surface of the silicon wafer is preferably 2000 mN/25 mm or less, especially 1000 mN/25 mm or less, and even more preferably 200 mN/25 mm or less. With an adhesion force of 2000 mN/25 mm or less, subsequent interfacial ablation facilitates the easy and effective separation of small workpiece pieces. Furthermore, the lower limit of the adhesion force is not particularly limited; for example, it can be 5 mN/25 mm or more, especially 10 mN/25 mm or more, and even 20 mN/25 mm or more.

Furthermore, the details of the methods for measuring such adhesive forces are described in the following experimental examples.

6. Manufacturing Method of the Workpiece Processing Sheet The manufacturing method of the workpiece processing sheet 1 in this embodiment is not particularly limited. For example, the interface ablation layer 11 can be formed directly on the substrate 12, or the interface ablation layer 11 can be formed on a processing sheet and then transferred onto the substrate 12.

When the interface ablation layer 11 contains an adhesive as one of its constituent components, the formation of the interface ablation layer 11 can be carried out by known methods. For example, a coating solution containing an adhesive composition for forming the interface ablation layer 11 and a solvent or dispersion medium as needed is prepared. Then, the coating solution is applied to one side of the substrate or the peelable side of the peel (hereinafter sometimes referred to as the "peelable surface"). Next, the interface ablation layer 11 can be formed by drying the obtained coating film.

The coating of the aforementioned coating liquid can be carried out by known methods, such as rod coating, blade coating, roller coating, wing coating, mold coating, gravure coating, etc. Furthermore, the properties of the coating liquid are not particularly limited as long as it is coatable; the components used to form the interface ablation layer 11 are sometimes contained as a solute and sometimes as a dispersed phase. In addition, when forming the interface ablation layer 11 on a release sheet, the release sheet can also be used as a process material for peeling, and the interface ablation layer 11 can be protected during the period until it is attached to the substrate.

When the adhesive composition used to form the interface ablation layer 11 contains the aforementioned crosslinking agent, it is preferable to form a crosslinked structure in the interface ablation layer 11 at a desired density by changing the drying conditions (temperature, time, etc.) or by additionally providing a heating treatment, so that the crosslinking reaction between the polymer component and the crosslinking agent in the coating film can proceed. Furthermore, in order to ensure that the aforementioned crosslinking reaction proceeds sufficiently, after the workpiece processing sheet 1 is completed, for example, it can be left to stand in an environment of 23°C and 50% relative humidity for several days to carry out so-called curing.

7. Method of Using the Workpiece Processing Sheet The workpiece processing sheet 1 of this embodiment is suitable for handling small workpiece pieces. As described above, the workpiece processing sheet 1 of this embodiment, since the interface ablation layer 11 is efficiently ablated by laser light irradiation, allows for high-precision separation of small workpiece pieces held on the interface ablation layer 11 at specific locations.

As an example of the method of using the workpiece processing piece 1 related to this embodiment, a method can be listed such as selectively separating any one of the plurality of workpiece pieces on the opposite side of the substrate 12 in the interface ablation layer 11 from the interface ablation layer 11 by causing interface ablation locally.

In the above-described method of use, the plurality of workpiece pieces held on the interface ablation layer 11 can be obtained by individually sheeting the workpiece (the material that becomes the workpiece piece) held on the surface opposite to the substrate 12 in the interface ablation layer 11. In other words, the workpiece pieces can also be obtained by cutting the workpiece on the interface ablation layer 11. Alternatively, the workpiece pieces can also be formed independently of the workpiece processing piece 1 associated with this embodiment and then placed on the interface ablation layer 11.

Furthermore, when the workpiece processing sheet 1 of this embodiment has the aforementioned adhesive layer and protective film forming layer, it is preferable to cut these layers and the workpiece on the interface ablation layer 11. In this way, a small workpiece sheet formed by stacking these layers can be obtained.

While the shape and size of the workpiece piece in this embodiment are not particularly limited, regarding size, it is preferable that the area of the workpiece piece when viewed from the side is 10 ^μm² or more, and more preferably 100 ^μm² or more. Furthermore, it is preferable that the area of the workpiece piece when viewed from the side is 1 ^mm² or less, and more preferably 0.25 ^mm² or less. In addition, as for the dimension of the workpiece piece, when the workpiece piece is rectangular, it is preferable that the smallest side of the workpiece piece is 2 μm or more, and more preferably 5 μm or more, and even more preferably 10 μm or more. Furthermore, it is preferable that the smallest side is 1 mm or less, and more preferably 0.5 mm or less. Specific examples of the dimension of a rectangular workpiece piece include 2 μm × 5 μm, 10 μm × 10 μm, 0.5 mm × 0.5 mm, 1 mm × 1 mm, etc. The workpiece processing sheet 1 of this embodiment can handle small workpiece pieces well, especially small workpiece pieces that are not easily separated from sheets as small as needle tips. On the other hand, the workpiece processing sheet 1 of this embodiment can also handle larger workpiece pieces with an area exceeding 1 ^mm² (e.g., 1 ^mm² to 2000 ^mm² ) and a thickness of 1 to 10000 μm (e.g., 10 to 1000 μm).

Examples of workpiece pieces include semiconductor components and semiconductor devices; more specifically, they include micro-light-emitting diodes (LEDs), power devices, and MEMS (Micro Electro Mechanical Systems). Among these, using workpiece pieces as light-emitting diodes is suitable, especially those selected from miniature LEDs and micro-LEDs. In recent years, research has focused on the development of devices with high-density configurations of miniature LEDs and micro-LEDs. In the manufacture of such devices, the workpiece processing piece 1 related to this embodiment, which allows for high-precision operation of these LEDs, is highly suitable.

The following describes the device manufacturing method with reference to FIG2 as a specific example of the use of the workpiece processing piece 1. The device manufacturing method includes at least three steps: a preparation step (FIG. 2(a)), a configuration step (FIG. 2(b)), and a separation step (FIG. 2(c) and (d)).

In the preparation step, as shown in FIG. 2(a), in the workpiece processing sheet 1 of this embodiment, a laminate consisting of a plurality of workpiece pieces 2 held on the surface of the interface ablation layer 11 is prepared. This laminate can be prepared by placing separately manufactured workpiece pieces 2 onto the workpiece processing sheet 1, or by individually cutting (i.e., dicing) the workpieces held on the surface of the interface ablation layer 11. This cutting can be performed using known methods.

The shape and size of the workpiece piece 2 are as described above and are not particularly limited, and the preferred size is also as described above. Specific examples of the workpiece piece 2 are as described above, such as semiconductor components, semiconductor devices, etc., and in particular, light-emitting diodes such as miniature light-emitting diodes and micro light-emitting diodes.

In the subsequent configuration steps, as shown in FIG2(b), the object 3 that can accommodate the workpiece piece 2 is configured such that the surface of the laminate faces the side of the workpiece piece 2 in the laminate. Although the example of the object 3 is appropriately determined according to the manufacturing device, specific examples of the object 3 for the workpiece piece 2 being a light-emitting diode include substrates, sheets, reels, etc., and wiring substrates with wiring are particularly suitable.

Subsequently, in the separation step, firstly, as shown in FIG. 2(c), laser light is irradiated onto the interface ablation layer 11 in the aforementioned laminate, at the location where at least one workpiece piece 2 is attached. This irradiation can also be performed simultaneously on multiple locations where workpiece pieces 2 are attached, or sequentially on these locations. The irradiation conditions for the laser light are not limited as long as they enable interface ablation to occur. Known devices can be used as the irradiation apparatus.

As shown in FIG. 2(d), interface ablation can occur at the irradiated location in the interface ablation layer 11 by the aforementioned irradiation. Specifically, by laser irradiation, the components constituting the region of the interface ablation layer 11 near the substrate 12 evaporate or volatilize, forming a reaction region 13. Then, the gas generated by the aforementioned evaporation or volatilization remains between the substrate 11 and the reaction region 13, forming a bubble 5. By forming the bubble 5, the interface ablation layer 11 is locally deformed at the location of the workpiece piece 2', so that the workpiece piece 2' is separated from the interface ablation layer 11 by peeling off. Based on the above, the workpiece piece 2' located at the interface ablation site can be placed on the object 3.

Furthermore, the reaction area 13 and the bubbles 5 generated by laser irradiation usually remain after the separation of the workpiece piece 2'. Figure 3 shows the separation of the workpiece piece 2 by sequential laser irradiation, especially the state after separation (two on the left), the state during separation (center), and the state before separation (two on the right). As shown, the bubbles 5 after separation are usually slightly deflated compared to the bubbles 5 during separation.

Furthermore, when the interface ablation layer 11 in this embodiment is an adhesive layer composed of an active energy line hardening adhesive, the aforementioned device manufacturing method can also include the subsequent hardening step. In other words, it can also include a hardening step by irradiating the entire interface ablation layer 11 in a laminate consisting of a plurality of workpiece pieces 2 maintained on the side surface of the interface ablation layer 11, or by irradiating an active energy line on a location in the interface ablation layer 11 in the laminate where at least one workpiece piece 2 is attached, thereby hardening the entire or partial interface ablation layer 11. This hardening step can be performed before the aforementioned separation step, or it can be performed simultaneously with the aforementioned separation step.

As described above, by irradiating the interface ablation layer 11 with active energy lines, the adhesion force between the workpiece piece 1 and the workpiece piece 2 can be reduced, making it easier to separate the workpiece piece 2 when interface ablation occurs. The irradiation with active energy lines in the hardening step can be performed using known methods, such as using a high-pressure mercury lamp or an ultraviolet LED irradiation device, or a laser irradiation device that can also be used in the separation step. When performing both the hardening and separation steps simultaneously, it is preferable to use the laser light 4 from the laser irradiation device as a combined irradiation with the active energy line irradiation.

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

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

Furthermore, the workpiece processing sheet 1 of this embodiment can also be used in a method for selectively removing specific workpiece pieces 2 from among a plurality of workpiece pieces 2 disposed on the sheet.

For example, after manufacturing a plurality of light-emitting diodes on the workpiece processing sheet 1 related to this embodiment, the light-emitting diodes are inspected on the sheet. At this point, interface ablation can be performed only on the light-emitting diodes that are identified as defective, thereby removing them from the workpiece processing sheet 1.

Furthermore, the assembly of these good products can be transferred from the workpiece processing sheet 1 to the transport sheet. At this time, when the interface ablation layer 11 is composed of the aforementioned active energy line hardening adhesive, by irradiating the interface ablation layer 11 with active energy lines, the adhesion of the workpiece processing sheet 1 to the light-emitting diode is reduced, allowing for a good transfer of the assembly of good products to the transport sheet. Afterwards, by placing another manufactured good product at the location where the defective product was removed, a workpiece processing sheet 1 containing only good products can be obtained.

As mentioned above, the method of removing defective products by interface ablation eliminates the need for sheet stretching and defective product collection, thus minimizing changes in the spacing or displacement of the light-emitting diodes. Therefore, it is easy to transfer the image onto transport sheets.

The embodiments described above are for the purpose of facilitating understanding of the present invention and are not intended to limit the scope of the present invention. Therefore, the elements disclosed in the above embodiments encompass all design variations and equivalents within the technical field to which the present invention pertains.

For example, other layers may be deposited between the interface ablation layer 11 and the substrate 12 in the workpiece processing sheet 1 of this embodiment, or on the surface of the substrate 12 opposite to the interface ablation layer 11. Specific examples of such other layers include an adhesive layer. In this case, the separation steps described above can be performed with the adhesive layer side attached to a support (a transparent substrate such as a glass plate).

The adhesive used to form the adhesive layer is not particularly limited, but it is preferable to use one that does not easily absorb or block active energy lines. In this case, when laser light is irradiated through the adhesive layer, the laser light can easily reach the interface ablation layer 11, effectively causing interface ablation. Specifically, it is preferable to use an adhesive that does not have active energy line curing properties, especially an adhesive that does not contain active energy line curing components. By using an adhesive that does not have active energy line curing properties, the adhesive layer will not harden even when irradiated with laser light, thus preventing unintended peeling of the workpiece processing sheet 1 from the transparent substrate. While not particularly limited in thickness, the thickness of the adhesive layer described above is preferably, for example, 5 to 50 μm. [Example]

The present invention will be further explained below by means of embodiments, etc., but the scope of the present invention is not limited to these embodiments.

[Example 1] (1) Preparation of the adhesive composition 70 parts by weight of 2-ethylhexyl acrylate and 30 parts by weight of 2-hydroxyethyl acrylate were polymerized by solvent polymerization to obtain a (meth)acrylate polymer. This (meth)acrylate polymer was then reacted with 90 moles of methacryloyloxyethyl isocyanate (MOI) relative to this 2-hydroxyethyl acrylate to obtain a (meth)acrylate copolymer with active energy line-curing groups introduced on the side chains (active energy line-curing polymer (A)). The weight average molecular weight (Mw) of this active energy line-curing polymer (A) was determined by the above method and was 800,000.

100 parts by weight (solids conversion, the same below) of the active energy line hardening polymer (A) obtained as described above, 2.5 parts by weight of trihydroxymethylpropane-modified methylphenyl diisocyanate (manufactured by Tosoh Corporation, trade name "Coronate L") as a crosslinking agent, and 4 parts by weight of acetone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(0-acetyloxime) (manufactured by BASF Corporation, trade name "Irugacure OXE02") as a photopolymerization initiator were mixed in a solvent to obtain a coating solution of an adhesive composition with a solids concentration of 30% by weight.

(2) Fabrication of the workpiece treatment sheet On the easily bonded surface of a single-sided easily bonded polyethylene terephthalate film (Toyoshoku, product name "COSMOSHINE A4100", thickness: 50μm), which serves as the substrate, a coating liquid of the adhesive composition obtained in step (1) above is applied. The obtained coating film is then dried by heating. This forms a 30μm thick interfacial ablation layer (adhesive layer) on the substrate.

Next, the side of the interface ablation layer opposite to the substrate is bonded to the release surface of a 38μm thick polyethylene terephthalate film formed by a silicone-based release agent layer on one side (manufactured by LINTEC Corporation, product name "SP-PET381031"). In this way, a workpiece processing sheet is obtained, which is formed by sequentially stacking the release sheet, the interface ablation layer, and the substrate.

(3) Determination of Weight-Average Molecular Weight The weight-average molecular weight (Mw) mentioned above is the converted standard polystyrene weight-average molecular weight determined using gel osmosis chromatography (GPC) under the following conditions (GPC determination). <Determination Conditions> • Measurement Apparatus: Tosoh Corporation, HLC-8320 • GPC Column (passed in the following order): Tosoh Corporation TSK gel super H-H TSK gel super HM-H TSK gel super H2000 • Measurement Solvent: Tetrahydrofuran • Measurement Temperature: 40℃

[Examples 2-3 and Comparative Examples 1-3] The workpiece treatment sheets were manufactured in the same manner as in Example 1, except that the type and content of the photopolymerization initiator were changed as shown in Table 1. Comparative Example 1 is an example in which no photopolymerization initiator was used.

[Experimental Example 1] (Determination of Ultraviolet Absorbance) The workpieces manufactured in the Embodiment and Comparative Examples were peeled off to expose the interface ablation layer. For this workpiece, the ultraviolet absorbance was measured using a UV-Vis-NIR spectrophotometer (Shimadzu Corporation, product name "UV-3600") and its associated large sample chamber (Shimadzu Corporation, product name "MPC-3100"). The measurement was performed by irradiating the surface of the interface ablation layer with light of 355nm through a 20nm slit using the integrating sphere built into the large sample chamber. The results are shown in Table 1.

[Experimental Example 2] (Determination of Adhesion) The workpiece preparation sheets manufactured in the Embodiment and Comparative Examples were cut into short strips 25 mm wide. The peeling sheet was removed from the obtained short strips of workpiece preparation sheet, and the exposed surface of the etched interface layer was applied to the mirror surface of a mirror-finished silicon wafer using a 2 kg rubber roller in an environment of 23°C and 50% relative humidity. The sample was left to stand for 20 minutes as a sample for adhesion determination.

Subsequently, using a universal tensile testing machine (manufactured by ORIENTEC Corporation, product name "TENSILON UTM-4-100"), the workpiece was peeled from the silicon wafer at a peeling speed of 300 mm/min and a peeling angle of 180°. The adhesion force (mN/25 mm) to the mirror surface of the silicon wafer was measured using the 180° peeling method based on JIS Z0237:2009. The results are presented in Table 1 as the adhesion force before UV irradiation.

Furthermore, for the interface ablation layer in the same adhesive strength test sample obtained as described above, an ultraviolet irradiation device (manufactured by LINTEC Corporation, product name "RAD-2000") equipped with a high-pressure mercury lamp as a light source was used to irradiate the interface ablation layer with ultraviolet light (illuminance: 230mW/ ^cm² , light intensity: 190mJ/ ^cm² ) in between, causing the interface ablation layer to harden. The adhesive strength (mN/25mm) to the mirror surface of the silicon wafer was measured for this ultraviolet-irradiated sample in the same manner as described above. These results are presented as adhesive strength after ultraviolet irradiation in Table 1.

[Experimental Example 3] (Evaluation of Laser Peeling Suitability) (1) Preparation of Wafers on the Workpiece Processing Wafer (Preparation Steps) On one side of a silicon wafer (#2000, thickness: 350μm), attach the adhesive side of a dicing blade (manufactured by LINTEC Corporation, product name "D-485H"). Next, attach a dicing ring frame to the periphery of the aforementioned adhesive side of the dicing blade (the area not overlapping with the silicon wafer). Further, cut the dicing blade according to the outer diameter of the ring frame. Then, using a dicing device (manufactured by Disco Corporation, product name "DFD6362"), dic the silicon wafer into wafers with dimensions of 300μm × 300μm. Then, the diced wafer is irradiated with ultraviolet light (illuminance 230mW/ ^cm2 , light intensity 190mJ/ ^cm2 ) to obtain a stack consisting of multiple wafers disposed on the diced wafer.

Next, a peeling sheet is peeled off from the workpiece sheet manufactured in the embodiments and comparative examples, and the exposed surface is then bonded to the surface of the laminate obtained as described above, where a plurality of wafers exist. Then, a dicing sheet is peeled off from the plurality of wafers. In this way, the plurality of wafers are transferred from the dicing sheet to the workpiece sheet, resulting in a laminate on the workpiece sheet containing a plurality of wafers.

(2) Separation of wafers irradiated by laser light (separation step) For the laminate obtained in step (1) above, consisting of a plurality of wafers disposed on a workpiece wafer, a laser light irradiation device is used to irradiate the wafers with laser light through the workpiece wafer.

Specifically, a laser irradiation device (manufactured by KEYENCE Corporation, product name "MD-U1000C") is used to irradiate the wafer with a wavelength of 355nm through the workpiece. The irradiation is performed by sequentially irradiating the center of the wafer with a laser spot in a circular pattern. The laser spot diameter is 25μm, and the inner diameter of the ring formed by the irradiation trajectory is 65μm. Other irradiation conditions are: frequency: 40kHz, scan speed: 500mm/s, irradiation dose: 50μJ/shot. Furthermore, the irradiation is performed on 100 wafers selected from a plurality of wafers (a total of 10 wafers x 10 wafers).

(3) Confirmation of Bubble Formation and Wafer Separation For the workpiece wafers and wafers subjected to the above irradiation, confirm whether bubbling occurred at the interface between the substrate and the interface ablation layer in the workpiece wafer, and whether wafers detached from the workpiece wafer. Evaluate the suitability of laser peeling according to the following criteria. The results are shown in Table 1. ◎…Bubble formation occurred at all 100 wafer locations, and all 100 wafers detached. ○…The number of bubbling and detached wafers is 80 or more, but less than 100. ×…The number of bubbling and detached wafers is less than 80.

Furthermore, details of the abbreviations, etc., recorded in Table 1 are as follows: IrugacureOXE02: Ethyl ketone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(0-acetyloxime) (Manufactured by BASF, product name "IrugacureOXE02") Omnirad379: 2-Dimethylamino-2-(4-methylbenzyl)-1-(4-morpholinyl-phenyl)butane-1-one (Manufactured by IGM Resins, product name "Omnirad379") Omnirad651: 2,2-Dimethoxy-1,2-diphenylethane-1-one (Manufactured by IGM Resins, product name "Omnirad651")

[Table 1] Photopolymerization initiator Ultraviolet absorbance Adhesion force (mN/25mm) Laser exfoliation suitability Kind Content (parts by mass) Before UV irradiation After ultraviolet radiation Implementation Example 1 Irugacure OXE02 4 2.40 2300 30 ○ Implementation Example 2 Irugacure OXE02 8 3.36 2200 30 ◎ Implementation Example 3 Omnirad 379 20 3.21 2100 30 ◎ Comparative example 1 - - 0.10 2200 2200 × Comparative example 2 Omnirad 651 20 1.08 1700 30 × Comparative example 3 Irugacure OXE02 0.5 0.44 2200 30 ×

As clearly shown in Table 1, the workpiece processing disc manufactured in the embodiment exhibits excellent suitability for laser peeling. [Industrial Applicability]

The workpiece processing sheet of this invention can be appropriately used in the manufacture of displays and the like that have micro-light-emitting diodes as pixels.

1: Workpiece processing sheet 11: Interface ablation layer 12: Substrate 13: Reaction area 2,2’: Small workpiece piece 3: Object 4: Laser light 5: Bubble expansion 6: Laser light irradiation point

[Figure 1] is a cross-sectional view of a workpiece processing sheet according to an embodiment of the present invention. [Figure 2] is a cross-sectional view illustrating a method for manufacturing an apparatus using a workpiece processing sheet according to an embodiment of the present invention. [Figure 3] is a cross-sectional view illustrating the state of the bubbles and reaction zones generated by laser irradiation.

1: Workpiece processing sheet

11: Interface Burn-in Layer

12: Substrate

Claims (16)

A workpiece processing sheet comprising: a substrate, and an interface ablation layer deposited on one side of the substrate for holding a small workpiece piece and subject to interface ablation by laser light irradiation, characterized in that: the interface ablation layer contains a photopolymerization initiator but does not contain a gas generator, and the absorbance of light with a wavelength of 355 nm of the workpiece processing sheet is 1.5 or more. The workpiece processing sheet as described in claim 1, wherein the aforementioned photopolymerization initiator has an absorption peak in the wavelength range of 200 nm to 400 nm. The workpiece processing sheet as described in claim 1, wherein the aforementioned interface ablation layer is an adhesive layer. The workpiece processing sheet as described in claim 3, wherein the adhesive constituting the adhesive layer is an active energy line hardening adhesive. The workpiece processing sheet as described in claim 3, wherein the adhesive constituting the adhesive layer is an acrylic adhesive. The workpiece processing sheet as described in claim 1, wherein the laser light is of a wavelength having an ultraviolet region. The workpiece processing sheet as described in claim 1, wherein when interface ablation occurs in the aforementioned interface ablation layer, a bubble is formed at the location where the interface ablation occurs. The workpiece processing sheet as described in claim 1, wherein it is used to selectively separate any one of a plurality of workpiece pieces on the opposite side of the substrate in the interface ablation layer by causing localized interface ablation on the interface ablation layer. The workpiece processing sheet as described in claim 8, wherein the aforementioned workpiece piece is obtained by individually processing a workpiece held in the interface ablation layer on the surface opposite to the aforementioned substrate on that surface. The workpiece processing piece as described in claim 8, wherein the workpiece piece is selected from at least one of semiconductor components and semiconductor devices. The workpiece processing piece as described in claim 8, wherein the aforementioned workpiece piece is a light-emitting diode selected from miniature light-emitting diodes and micro light-emitting diodes. A method for manufacturing an apparatus, characterized by comprising: a preparation step of preparing a laminate having a substrate and an interface ablation layer containing a photopolymerization initiator and not containing a gas generator, deposited on one side of the substrate, and a workpiece processing sheet having an absorbance of 1.5 or more for light at a wavelength of 355 nm, and maintaining a plurality of workpiece pieces on the surface of the interface ablation layer; a configuration step of arranging the laminate with the workpiece pieces facing the surface of the laminate, for an object capable of accommodating the workpiece pieces; and a further configuration step of arranging the laminate with the workpiece pieces facing the surface of the laminate; and A laser beam is irradiated at a location in the interface ablation layer of the aforementioned laminate where at least one of the aforementioned workpiece pieces is attached. By causing interface ablation at the irradiated location in the interface ablation layer, the aforementioned workpiece piece present at the interface ablation location is separated from the aforementioned workpiece processing sheet, and the aforementioned workpiece piece is placed on the aforementioned object in a separation step. The device manufacturing method as described in claim 12, wherein, in the preparation step described above, a workpiece maintained on the surface opposite to the substrate in the interface ablation layer is individually sheeted on that surface to obtain the workpiece piece. The method of manufacturing the device as described in claim 12, wherein the aforementioned workpiece piece is selected from at least one of semiconductor components and semiconductor devices. The method of manufacturing the device as described in claim 12, wherein a light-emitting device having a plurality of the aforementioned light-emitting diodes is manufactured by using a light-emitting diode selected from miniature light-emitting diodes and micro light-emitting diodes as the aforementioned workpiece piece. The method of manufacturing the device as described in claim 15, wherein the light-emitting device is a display.