WO2022201767A1

WO2022201767A1 - Workpiece handling sheet and device manufacturing method

Info

Publication number: WO2022201767A1
Application number: PCT/JP2022/000965
Authority: WO
Inventors: 健太古野; 彰朗福元; 洋司若山; 喜章古川
Original assignee: リンテック株式会社
Priority date: 2021-03-26
Filing date: 2022-01-13
Publication date: 2022-09-29
Also published as: TW202239021A; JPWO2022201767A1

Abstract

Provided is a workpiece handling sheet 1 comprising: a substrate 12; and a resin layer 11 which is laminated on one surface of the substrate 12 and which can hold small workpieces, wherein the resin layer 11 contains 10 mass% or more of a laser beam absorbing component having absorbing properties relative to laser beam wavelengths, and the resin layer 11 performs full ablation by laser beam irradiation. This workpiece handling sheet allows for proper handling even of very small workpieces.

Description

Work handling sheet and device manufacturing method

The present invention relates to a work handling sheet that can be used to handle small work pieces such as semiconductor components and semiconductor devices, and a device manufacturing method using the work handling sheet. (Micro Electro Mechanical Systems), etc., and a device manufacturing method using the work handling sheet.

In recent years, the development of displays using micro-light-emitting diodes has progressed. In such displays, individual pixels are composed of micro-light-emitting diodes, and the light emission of each micro-light-emitting diode is independently controlled. In the manufacture of such displays, it is generally necessary to mount micro-light-emitting diodes, which are arranged on a supply substrate such as sapphire, glass, etc., onto a wiring substrate provided with wiring.

During the mounting, it is necessary to accurately place the plurality of micro light-emitting diodes arranged on the supply board at predetermined positions on the wiring board. At this time, it is necessary to selectively mount a predetermined one of the plurality of micro light emitting diodes on the wiring board, or 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, by irradiating the layer with laser light, the layer is ablated at the irradiated position, thereby supporting the layer. A method of mounting a micro light-emitting diode separated from a body (laser lift-off) on a wiring board is being studied (Patent Document 1). Since the laser beam has excellent 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. There is a need for means that can handle fine work pieces such as micro light emitting diodes.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and provides a work handling sheet capable of handling even fine work piece pieces well, and a device manufacturing method using the work handling sheet. for the purpose.

In order to achieve the above object, firstly, the present invention provides a work handling sheet comprising a base material and a resin layer laminated on one side of the base material and capable of holding a small work piece, wherein the resin A work handling sheet, wherein the layer contains 10% by mass or more of a laser light-absorbing component that absorbs the wavelength of the laser light, and the resin layer is fully ablated by the irradiation of the laser light. Provide (Invention 1).

In the work handling sheet according to the above invention (invention 1), the resin layer contains the above-mentioned amount of a laser light absorbing component that has an absorptivity to the wavelength of the laser light, so that it is effective when irradiated with a laser light. Full ablation can be achieved in a targeted manner, thereby providing good separation of the work piece towards the object.

A second aspect of the present invention is a work handling sheet comprising a base material and a resin layer laminated on one side of the base material and capable of holding a small work piece, wherein the resin layer is adapted to the wavelength of laser light. When the content of the laser light absorbing component in the resin layer is X mass % and the thickness of the resin layer is Y μm, X is Y Provided is a work handling sheet characterized in that the divided value (X/Y) is 2.0 or more (Invention 2).

In the work handling sheet according to the above invention (invention 2), the resin layer contains a laser light absorbing component having an absorptivity to the wavelength of the laser light, satisfying the above-described conditions regarding the thickness of the resin layer. , effective full ablation when irradiated with a laser beam, so that the work piece can be directed to the object and separated well.

In the above inventions (Inventions 1 and 2), the laser light absorbing component is preferably at least one of an ultraviolet absorber and a photopolymerization initiator (Invention 3).

In the above invention (invention 3), the ultraviolet absorber is preferably an organic compound (invention 4).

In the above inventions (inventions 3 and 4), the ultraviolet absorber is preferably a compound having one or more heterocycles (invention 5).

In the above inventions (inventions 3 to 5), the ultraviolet absorber has at least one of a carbocyclic ring and a heterocyclic ring, and all the carbocyclic rings and heterocyclic rings of the ultraviolet absorbent are monocyclic. It is preferable that there is (Invention 6).

In the above inventions (inventions 3 to 6), the ultraviolet absorber is preferably a compound having a plurality of aromatic rings (invention 7).

In the above inventions (Inventions 1 to 7), the resin layer is preferably an adhesive layer (Invention 8).

In the above invention (invention 8), the adhesive constituting the adhesive layer is preferably an acrylic adhesive (invention 9).

In the above inventions (inventions 1 to 9), the laser light preferably has a wavelength in the ultraviolet region (invention 10).

In the above inventions (inventions 1 to 10), any of a plurality of work pieces held on the surface of the resin layer opposite to the substrate by full abrasion locally generated in the resin layer (Invention 11).

In the above invention (invention 11), the work pieces are obtained by singulating a work held on a surface of the resin layer opposite to the base material on the surface. Preferred (Invention 12).

In the above inventions (inventions 11 and 12), the work pieces are preferably at least one selected from semiconductor components and semiconductor devices (invention 13).

In the above inventions (inventions 11 to 13), the work pieces are preferably light emitting diodes selected from mini light emitting diodes and micro light emitting diodes (invention 14).

The third aspect of the present invention is the work handling sheet (inventions 1 to 14), wherein a preparation step of preparing a laminate in which a plurality of small work pieces are held on the surface on the resin layer side; an arrangement step of arranging the laminate so that the surface of the laminate on the side of the small work piece faces a possible object; By irradiating a laser beam to the position where the resin layer is exposed to cause full ablation at the irradiated position, the work piece present at the position where the full ablation has occurred is removed from the work handling sheet and a separation step of separating and placing the work pieces on the object (Invention 15).

In the above invention (invention 15), in the preparation step, the workpiece held on the surface of the resin layer opposite to the base material is singulated on the surface to obtain the workpiece pieces. is preferred (Invention 16).

In the above inventions (inventions 15 and 16), the work pieces are preferably at least one selected from semiconductor components and semiconductor devices (invention 17).

In the above inventions (Inventions 15 to 17), it is preferable to manufacture a light emitting device comprising a plurality of the light emitting diodes by using a light emitting diode selected from mini light emitting diodes and micro light emitting diodes as the work piece (Invention 18). .

In the above invention (invention 18), the light-emitting device is preferably a display (invention 19).

The work handling sheet according to the present invention can handle even fine work pieces well, and according to the device manufacturing method according to the present invention, devices with excellent performance can be manufactured.

1 is a cross-sectional view of a work handling sheet according to one embodiment of the present invention; FIG. FIG. 4 is a cross-sectional view illustrating a device manufacturing method using a work handling sheet according to one embodiment of the present invention;

Embodiments of the present invention will be described below.
FIG. 1 shows a cross-sectional view of a work handling sheet according to one embodiment. A work handling sheet 1 shown in FIG. 1 includes a substrate 12 and a resin layer 11 laminated on one side of the substrate 12 .

In the work handling sheet 1 according to this embodiment, the resin layer 11 can hold small work pieces. That is, the work handling sheet 1 according to the present embodiment can hold the small work piece laminated on the surface of the resin layer 11 opposite to the base material 12 as it is.

Although the specific mode of holding is not limited, a preferable example is that the resin layer 11 exhibits adhesiveness to the small piece of work to hold it. In this case, as will be described later, the resin layer 11 preferably contains an adhesive as one of its constituent components, that is, it is an adhesive layer.

In the work handling sheet 1 according to the present embodiment, the resin layer 11 contains 10% by mass or more of a laser light-absorbing component having an absorptivity to the wavelength of the laser light, and is fully absorbed by the irradiation of the laser light. Ablation is preferred (these conditions may be hereinafter referred to as "Condition 1").

In addition, in the work handling sheet 1 according to the present embodiment, the resin layer 11 contains a laser light-absorbing component that absorbs the wavelength of the laser light, and the laser light-absorbing component in the resin layer 11 When the content is X mass % and the thickness of the resin layer 11 is Y μm, the value obtained by dividing X by Y (X/Y) is preferably 2.0 or more (hereinafter, these conditions is sometimes referred to as "condition 2").

The work handling sheet 1 according to the present embodiment satisfies at least one of the

conditions

1 and 2 described above, so that it can be satisfactorily fully ablated when irradiated with a laser beam.

In this specification, full ablation means that the components constituting the resin layer 11 evaporate or volatilize due to the energy of the laser light, and as a result, the portion of the resin layer 11 irradiated with the laser light disappears. At the time of disappearance, decomposition of the components constituting the resin layer 11 may or may not occur. Then, the small work pieces that existed at the disappeared position lose their existence to hold them and are separated from the work handling sheet 1 according to the present embodiment.

As a conventional work handling sheet, there is a sheet that separates small work pieces by creating a gap at the interface between the base material and the resin layer by irradiating a laser beam, thereby expanding the resin layer. On the other hand, in the work handling sheet 1 according to the present embodiment, it is possible to separate the small work pieces without causing such swelling of the resin layer. It is possible to bring the distance to the receiving target closer. Therefore, the positional accuracy is extremely high when separating the small work piece from the object.

Furthermore, the work handling sheet 1 according to the present embodiment contains a laser light absorbing component while satisfying Condition 1 or Condition 2, thereby improving the efficiency with which the resin layer 11 receives energy from the laser light. As a result, full ablation is effectively generated, and the retained work pieces can be separated satisfactorily from the resin layer 11 . In particular, the amount of laser light irradiation required to cause sufficient separation of the work pieces is reduced, the operating cost of the laser light irradiation device can be reduced, and only the target work pieces are easily separated. In addition, it is possible to prevent damage to the device and small pieces of work due to excessive laser light irradiation.

The laser light is not particularly limited as long as it can cause full ablation, and may be a laser light having any wavelength in the ultraviolet region, the visible light region, and the infrared region. is preferred.

1. Resin Layer The specific configuration and composition of the resin layer 11 in the present embodiment are not particularly limited as long as they can hold the work pieces and satisfy at least one of the

conditions

1 and 2.

From the standpoint of easily exhibiting the property of being able to hold a small work piece, the resin layer 11 preferably contains an adhesive as one of its constituent components, as described above. When the resin layer 11 contains an adhesive, the resin layer 11 is preferably made of an adhesive composition containing a laser light absorbing component.

(1) Laser light-absorbing component The laser light-absorbing component is not particularly limited as long as it is a component that absorbs the wavelength of the laser light, but it is preferably at least one of an ultraviolet absorber and a photopolymerization initiator. .

(1-1) Ultraviolet Absorber The type of ultraviolet absorber is not particularly limited. The ultraviolet absorber in this embodiment may be an organic compound or an inorganic compound, but an organic compound is preferable from the viewpoint of facilitating good full ablation.

When the ultraviolet absorber is an organic compound, preferred examples of the ultraviolet absorber include hydroxyphenyltriazine-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, benzoate-based ultraviolet absorbers, and benzoxazinone. UV absorber, phenyl salicylate UV absorber, cyanoacrylate UV absorber, nickel complex UV absorber, hydroquinone UV absorber, salicylic acid UV absorber, malonic acid ester UV absorber, oxalic acid UV absorber Compounds such as absorbents can be mentioned. 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, from the viewpoint of having good absorption in the third harmonic (355 nm) of YAG and easily causing good full ablation, hydroxyphenyltriazine-based UV absorbers, benzophenone-based UV absorbers, It is preferable to use at least one of ultraviolet absorbers and benzotriazole-based ultraviolet absorbers, and it is particularly preferable to use hydroxyphenyltriazine-based ultraviolet absorbers.

As the hydroxyphenyltriazine-based UV absorber, 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- and triazine, etc. These may be used singly or in combination of two or more. Octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine and 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis It is preferred to use at least one of (4-phenylphenyl)-1,3,5-triazines.

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

In addition, as another chemical structural feature, the ultraviolet absorber in the present embodiment has at least one of a carbocyclic ring and a heterocyclic ring, and all the carbocyclic rings and heterocyclic rings possessed by the ultraviolet absorbent are monocyclic It is also preferable that

As a further chemical structural feature, the ultraviolet absorber in this embodiment is preferably 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, particularly preferably 3 or less.

In the chemical structural features described above, each heterocyclic ring preferably has at least one element selected from nitrogen, oxygen, phosphorus, sulfur, silicon and selenium as an element other than carbon, particularly , nitrogen, oxygen, phosphorus and sulfur. Moreover, the number of atoms constituting the ring structure of the heterocyclic ring 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 preferred heterocycles include triazine, benzotriazole, thiophene, pyrrole, imidazole, pyridine, pyrazine and the like.

In addition, in the chemical structural features described above, preferable examples of aromatic rings include benzene, naphthalene, anthracene, biphenyl, and triphenyl.

Examples of UV absorbers having the above-described chemical structural features include UV absorbers having the structure of the following formula (1) (tris[2,4,6-[2-{4-(octyl-2- methyl ethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine).

The ultraviolet absorber in this embodiment preferably has an absorption peak in the wavelength range of 250 nm or more and 400 nm or less. This makes it easier to produce good full ablation.

In addition, the ultraviolet absorber in the present embodiment preferably has an absorbance of light having a wavelength of 355 nm of 0.5 or more, particularly preferably 1.0 or more, and further preferably 1.2 or more. preferable. This makes it easier to produce good full ablation. The upper limit of the absorbance is not particularly limited, and may be 6.0 or less, for example.

The absorption peak and the absorbance of the ultraviolet absorber were obtained by preparing an acetonitrile solution with a concentration of 0.01% by mass, and attaching a large sample chamber (for example, manufactured by Shimadzu Corporation, product name "MPC-3100"). It can be measured using a spectrophotometer (eg, “UV-3600” manufactured by Shimadzu Corporation).

(1-2) Photopolymerization Initiator The type of photopolymerization initiator is not particularly limited. Examples of preferred photoinitiators include 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-phenyl)butan-1-one, ethanone, 1-[9-ethyl-6- (2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(0-acetyloxime), 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(O- benzoyloxime), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one It is preferred to use at least one.

Other photopolymerization initiators can be used together with the above photopolymerization initiators. Examples of photoinitiators that can be used together 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 -diphenylethan-1-one, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 4-(2-hydroxyethoxy ) phenyl-2-(hydroxy-2-propyl)ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-methylpropanone, benzophenone, p-phenylbenzophenone, 4,4′-diethylamino Benzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiary-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2 , 4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, oligo[2-hydroxy-2-methyl-1[4-(1-methylvinyl)phenyl]propanone], 2,4 , 6-trimethylbenzoyl-diphenyl-phosphine oxide and the like.

The photopolymerization initiator in the present embodiment preferably has an absorption peak in the wavelength range of 200 nm or more and 400 nm or less. As a result, the resin layer 11 efficiently absorbs the laser beam, thereby facilitating full ablation. From such a viewpoint, the lower limit of the above range is preferably 300 nm or more, and more preferably 330 nm or more. The upper limit of the above range is preferably 380 nm or less, more preferably 370 nm or less.

The above absorption peak can be specified based on the following method. First, a photopolymerization initiator is dissolved in methanol or acetonitrile as a solvent to prepare a measurement solution having a concentration of 0.01% by mass. Subsequently, the absorbance of the measurement solution is measured with a spectrophotometer (eg, “UV-3600” manufactured by Shimadzu Corporation) to obtain an absorption spectrum. Then, the wavelength range of the absorption peak (nm) can be specified from the obtained absorption spectrum.

Further, the photopolymerization initiator in the present embodiment preferably has an absorbance of 0.5 or more, particularly preferably 0.75 or more, at a wavelength of 355 nm in a solution having a concentration of 0.01% by mass. is preferably 1.0 or more. When the absorbance is 0.5 or more, the resin layer 11 efficiently absorbs the laser light, thereby making it easier to perform full ablation. The upper limit of the absorbance is not particularly limited, and may be, for example, 4.0 or less.

Incidentally, the above absorbance is obtained by preparing a methanol solution with a photopolymerization initiator concentration of 0.01% by mass (acetonitrile solution if the photopolymerization initiator is insoluble in methanol), and the wavelength range of 200 to 500 nm in the solution. was measured using an ultraviolet-visible-near-infrared (UV-Vis-NIR) spectrophotometer (manufactured by Shimadzu Corporation, product name "UV-3600", optical path length 10 mm).

(1-3) Blending amount of laser light absorbing component As described above, the work handling sheet 1 according to the present embodiment preferably satisfies at least one of Condition 1 and Condition 2 regarding the blending amount of the laser light absorbing component.

That is, when the condition 1 is satisfied, the content of the laser light absorbing component in the resin layer 11 is 10% by mass or more, preferably 13% by mass or more, and further preferably 16% by mass or more. is preferred. When the content of the laser light absorbing component is in such a range, the resin layer 11 efficiently absorbs the laser light, thereby favorably facilitating full ablation. Also, the content of the laser light absorbing component is preferably 60% by mass or less, particularly preferably 50% by mass or less, and further preferably 40% by mass or less. As a result, it becomes easier to secure the amount of components other than the laser light absorbing component (for example, an adhesive to be described later), and it becomes easier to obtain the work handling sheet 1 having desired performance.

Regarding condition 1, when the laser light absorbing component is blended in the adhesive composition described later, the content of the laser light absorbing component in the adhesive composition is the acrylic polymer (A) 100 described later. It is preferably 12 parts by mass or more, particularly preferably 16 parts by mass or more, further preferably 20 parts by mass or more. When the content of the laser light absorbing component is in such a range, the resin layer 11 efficiently absorbs the laser light, thereby favorably facilitating full ablation. In addition, the content of the laser light absorbing component in the adhesive composition is preferably 72 parts by mass or less, particularly 60 parts by mass or less, relative to 100 parts by mass of the acrylic polymer (A) described later. is preferred, and more preferably 48 parts by mass or less. As a result, it becomes easier to secure the amount of components other than the laser light absorbing component (for example, an adhesive to be described later), and it becomes easier to obtain the work handling sheet 1 having desired performance.

Further, when the condition 2 is satisfied, the value obtained by dividing X by Y (X /Y) is 2.0 or more, preferably 2.2 or more, and more preferably 2.3 or more. When the above value (X/Y) is within these ranges, the resin layer 11 efficiently absorbs the laser light, thereby making it easier to favorably perform full ablation. The value (X/Y) is preferably 60 or less, more preferably 40 or less, particularly preferably 10 or less, and further preferably 5 or less. As a result, it becomes easier to secure the amount of components other than the laser light absorbing component (for example, an adhesive to be described later), and it becomes easier to obtain the work handling sheet 1 having desired performance.

(2) Adhesive As described above, the resin layer 11 in this embodiment may contain an adhesive in addition to the laser light absorbing component. In this case, the resin layer 11 is preferably formed from an adhesive composition containing a laser light absorbing component.

The adhesive is not particularly limited as long as it can exhibit sufficient holding power (adhesive power) to adherends such as small pieces of work. Examples of the 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 that it is easy to exhibit the desired adhesive strength.

Examples of the acrylic pressure-sensitive adhesive include acrylic pressure-sensitive adhesives having an acrylic polymer (A) as a base polymer. The weight average molecular weight (Mw) of the acrylic polymer (A) is preferably 10,000 or more, particularly preferably 100,000 or more. Also, the weight average molecular weight (Mw) is preferably 2,000,000 or less, and more preferably 1,500,000 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 adhesive force to be obtained, and it becomes easy to suppress the adhesive residue on the separated work pieces. Further, when the weight average molecular weight is 2,000,000 or less, it becomes easier to obtain a stable coating film of the resin layer 11 . In addition, the weight average molecular weight (Mw) in this specification is the value of standard polystyrene conversion measured by the gel permeation chromatography method (GPC method).

Further, the glass transition temperature (Tg) of the acrylic polymer (A) is preferably -70°C or higher, and particularly preferably -60°C or higher. Also, the glass transition temperature (Tg) is preferably 20° C. or lower, particularly preferably 10° C. or lower. When the glass transition temperature (Tg) of the acrylic polymer (A) is within the above range, it becomes easy to achieve desired cohesive strength and desired adhesive strength.

The acrylic polymer (A) preferably contains at least a (meth)acrylic acid ester monomer as a constituent monomer, and has a functional group (hereinafter referred to as , also referred to as a “reactive functional group”).

Specific examples of the (meth)acrylate monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, 2-ethylhexyl ( Number of carbon atoms in alkyl groups such as meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, etc. Alkyl (meth)acrylates having 1 to 18 carbon atoms; Cycloalkyl (meth)acrylates having 1 to 18 carbon atoms in the cycloalkyl group, benzyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate , dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, imide (meth)acrylate and other (meth)acrylates having a cyclic skeleton; 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 include epoxy group-containing (meth)acrylates such as cyclo-2-hydroxypropyl (meth)acrylate.

Further, monomers other than (meth)acrylic acid ester monomers such as acrylic acid, methacrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide may be copolymerized. These may be used individually by 1 type, and may use 2 or more types together.

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, thereby making it easier to increase the cohesion of the resin layer 11. . Examples of the reactive functional group of the acrylic polymer (A) include carboxyl group, amino group, epoxy group, and hydroxyl group. Since it is easy to react with , it preferably contains a hydroxyl group.

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

The proportion of the monomer having a reactive functional group (hereinafter also referred to as a reactive group-containing monomer) in the total monomers constituting the acrylic polymer (A) is preferably 0.3% by mass or more, particularly 0.3% by mass or more. It is preferably 5% by mass or more. Moreover, 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 within this range, it becomes easier to achieve the desired adhesive strength while achieving the desired cohesive strength.

In addition, the acrylic polymer (A) preferably contains the above 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 an alkyl (meth)acrylate. preferably contains an alkyl (meth)acrylate having 4 to 8 carbon atoms in the alkyl group. When the acrylic polymer (A) contains the alkyl (meth)acrylate described above, the proportion of the alkyl (meth)acrylate in the total constituent monomers of the acrylic polymer (A) is 30% by mass or more. It is preferably 35% by mass or more, and particularly preferably 35% by mass or more. Moreover, the above ratio is preferably 99% by mass or less, and particularly preferably 95% by mass or less. By containing the alkyl (meth)acrylate within this range, it becomes easier to achieve the desired adhesive strength while achieving the desired cohesive strength.

The use of the cross-linking agent (B) is preferable from the viewpoint of facilitating adjustment of the storage elastic modulus of the resin layer 11 within a desired range. As the cross-linking agent (B), a polyfunctional compound having reactivity with the reactive functional groups of the acrylic polymer (A) or the like can be used. Examples of such polyfunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts, Reactive phenol resin etc. can be mentioned.

The amount of the cross-linking agent (B) is preferably 0.001 parts by mass or more, particularly preferably 0.1 parts by mass or more, relative to 100 parts by mass of the acrylic polymer (A). is preferably 0.2 parts by mass or more. In addition, the amount of the cross-linking agent (B) is preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less, and further preferably 5 parts by mass with respect to 100 parts by mass of the acrylic polymer (A). It is preferably no more than parts by mass.

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

In addition to the components described above, other additives may be added to the adhesive composition for forming the resin layer 11 . Examples of such additives 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 work pieces are easily separated. When a gas generating agent is used, gas may be generated over the entire resin layer 11 . In that case, it may be difficult to cause full ablation only at the intended position and separate only the small work pieces located there, and it may be difficult to separate the small work pieces satisfactorily.

(3) Thickness of Resin Layer The thickness of the resin layer 11 in the present embodiment is preferably 1 μm or more, particularly preferably 2 μm or more, further preferably 3 μm or more. When the thickness of the resin layer 11 is 1 μm or more, it becomes easy to cause good full abrasion. Also, the thickness of the resin layer 11 is preferably 60 μm or less, particularly preferably 40 μm or less, further preferably 20 μm or less. When the thickness of the resin layer 11 is 60 μm or less, the condition 2 described above can be easily satisfied.

2. Substrate The composition and physical properties of the substrate 12 in the present embodiment are not particularly limited. From the viewpoint that the work handling sheet 1 can easily exhibit the desired functions, the base material 12 is preferably made of resin. When the base material 12 is made of a resin, examples of the resin include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, and ethylene-norbornene. Polymer, polyolefin resin such as norbornene resin; ethylene-vinyl acetate copolymer; ethylene-(meth)acrylic acid copolymer, ethylene-(meth)methyl acrylate copolymer, other ethylene-(meth)acryl Ethylene-based copolymer resins such as acid ester copolymers; polyvinyl chloride-based resins such as polyvinyl chloride and vinyl chloride copolymers; (meth)acrylic acid ester copolymers; polyurethanes; polyimides; etc. Further, the resin constituting the base material 12 may be a crosslinked resin or a modified ionomer of the above resin. Further, the substrate 12 may be a single-layer film made of the resin described above, or may be a laminated film formed by laminating a plurality of such films. In this laminated film, the materials constituting each layer may be of the same type or of different types.

For the purpose of improving adhesion to the resin layer 11, the surface of the base material 12 in this embodiment may be subjected to surface treatment such as an oxidation method or roughening method, or a primer treatment. 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. A thermal spraying method and the like can be mentioned.

The base material 12 in this embodiment may contain various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, and fillers. Moreover, when the resin layer 11 contains a material that is cured by active energy rays, the substrate 12 preferably has transparency to the active energy rays.

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

The thickness of the base material 12 in this embodiment is preferably 10 μm or more, particularly preferably 30 μm or more, 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 100 μm or less. is most preferred. 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 the small work piece can be easily handled well.

3. Release sheet In the present embodiment, when the resin layer 11 contains an adhesive as one of its constituent components, the surface of the resin layer 11 opposite to the base material 12 is adhered 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 examples thereof include plastic films that have undergone a release treatment using 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-based release agent, a fluorine-based release agent, a long-chain alkyl-based release agent, or the like can be used.

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 resin layer 11 opposite to the substrate 12 . In the sheet, a workpiece is attached to the surface of the adhesive layer opposite to the resin layer 11, and the adhesive layer is diced together with the workpiece to obtain small workpieces laminated with the individualized adhesive layers. Obtainable. The chip can be easily fixed to the object on which the work piece is mounted by the individualized adhesive layer. Examples of the material constituting the adhesive layer include those containing a thermoplastic resin and a low-molecular-weight thermosetting adhesive component, those containing a B-stage (semi-cured) thermosetting adhesive component, and the like. It is preferable to use

In addition, in the work handling sheet 1 according to the present embodiment, a protective film-forming layer may be laminated on the surface of the resin layer 11 opposite to the substrate 12 . In such a sheet, a work is attached to the surface of the protective film-forming layer opposite to the resin layer 11, and the protective film-forming layer is diced together with the work, so that the individualized protective film-forming layers are laminated. A hardened work piece can be obtained. As the work, one having a circuit formed on one side is preferably used. In this case, a protective film-forming layer is usually laminated on the side opposite to the side 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 pieces. The protective film-forming layer is preferably made of an uncured curable adhesive.

5. Method for Manufacturing Work Handling Sheet A method for manufacturing the work handling sheet 1 according to the present embodiment is not particularly limited. For example, the resin layer 11 may be directly formed on the substrate 12, or the resin layer 11 may be formed on a process sheet and then transferred onto the substrate 12.

When the resin layer 11 contains an adhesive as one of its constituent components, the resin layer 11 can be formed by a known method. For example, a coating liquid containing an adhesive composition for forming the resin layer 11 and optionally a solvent or a dispersion medium is prepared. Then, the above coating liquid is applied to one side of the base material or the releasable side of the release sheet (hereinafter sometimes referred to as "release side"). Subsequently, the resin layer 11 can be formed by drying the obtained coating film.

The application of the coating liquid described above can be performed by a known method, for example, bar coating, knife coating, roll coating, blade coating, die coating, gravure coating, or the like. The properties of the coating liquid are not particularly limited as long as it can be applied, and the coating liquid may contain components for forming the resin layer 11 as solutes or dispersoids in some cases. . Further, when the resin layer 11 is formed on the release sheet, the release sheet may be released as a process material, or may protect the resin layer 11 until it is attached to an adherend.

When the adhesive composition for forming the resin layer 11 contains the above-described cross-linking agent, the drying conditions (temperature, time, etc.) described above may be changed, or heat treatment may be performed separately. It is preferable to promote a cross-linking reaction between the polymer component in the film and the cross-linking agent to form a cross-linked structure with a desired existence density in the resin layer 11 . Furthermore, in order to allow the cross-linking reaction to proceed sufficiently, after the work handling sheet 1 is completed, it may be cured by leaving it in an environment of, for example, 23° C. and a relative humidity of 50% for several days.

6. Method of Using Work Handling Sheet The work handling sheet 1 according to this 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, the resin layer 11 is efficiently fully ablated by laser light irradiation, so that the small work piece held on the resin layer 11 can be removed with high precision. It can be separated towards a predetermined position.

As an example of a method of using the work handling sheet 1 according to the present embodiment, a plurality of ablation held on the surface of the resin layer 11 opposite to the base material 12 by full abrasion locally generated in the resin layer 11 A method of use is to selectively separate any one of the small work pieces from the resin layer 11 .

In the method of use described above, the plurality of small work pieces held on the resin layer 11 are arranged so that the work (material of the small work pieces) held on the surface of the resin layer 11 opposite to the base material 12 is placed on the surface of the resin layer 11. It may be obtained by singulating in. That is, the work piece may be obtained by dicing the work on the resin layer 11 . Alternatively, the work piece may be formed independently of the work handling sheet 1 according to the present embodiment and placed on the resin layer 11 .

In addition, when the work handling sheet 1 according to the present embodiment includes the adhesive layer and the protective film forming layer described above, it is preferable to dice these layers and the work on the resin layer 11 . As a result, it is possible to obtain workpiece pieces in which these layers are separated into individual pieces and laminated.

Although the shape and size of the work piece in the present embodiment are not particularly limited, the work piece preferably has an area of 10 μm ² or more, particularly 100 μm ² or more, when viewed from above. In addition, the work piece preferably has an area of 1 mm ² or less, particularly preferably 0.25 mm ² or less when viewed from above. As for the size of the work piece, when the work piece is rectangular, the minimum side of the work piece is preferably 2 μm or more, particularly preferably 5 μm or more, and further preferably 10 μm or more. preferable. Moreover, 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 work piece 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, especially fine work pieces that are difficult to separate from the sheet by pushing up a needle. On the other hand, the work handling sheet 1 according to the present embodiment has a relatively large area, such as one having an area exceeding 1 mm ² (for example, 1 mm ² to 2,000 mm ² ) or having a thickness of 1 to 10,000 μm (for example, 10 to 1,000 μm). Work piece pieces of any size can also be handled well.

Examples of small work pieces 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 pieces are preferably light emitting diodes, and particularly preferably light emitting diodes selected from mini light emitting diodes and micro light emitting diodes. In recent years, the development of devices in which mini light emitting diodes and micro light emitting diodes are densely arranged has been studied. is very suitable.

As a specific usage example of the work handling sheet 1, a device manufacturing method will be described below with reference to FIG. The device manufacturing method includes at least three steps: a preparation step (FIG. 2(a)), an arrangement step (FIG. 2(b)), and a separation step (FIGS. 2(c) and (d)).

In the preparation process, as shown in FIG. 2(a), a laminate is prepared in which a plurality of small work pieces 2 are held on the resin layer 11 side surface of the work handling sheet 1 according to the present embodiment. The laminate may be prepared by placing a separately prepared work piece 2 on the work handling sheet 1, or a work held on the surface of the resin layer 11 side may be individually separated on the surface. may be prepared by slicing (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. Specific examples of the workpiece 2 also include, as described above, semiconductor components and semiconductor devices, and particularly light-emitting diodes such as mini light-emitting diodes and micro light-emitting diodes.

In the subsequent arranging step, as shown in FIG. 2B, the laminate is arranged so that the surface of the laminate on the side of the small work piece 2 faces the object 3 that can receive the small work piece 2. . Examples of the object 3 are appropriately determined according to the device to be manufactured. In particular, a wiring substrate provided with wiring is preferably used.

After that, in the separation step, first, as shown in FIG. 2(c), the position of the resin layer 11 of the laminate to which at least one work piece 2 is attached is irradiated with a laser beam. The irradiation may be performed simultaneously on a plurality of positions where the work pieces 2 are attached, or may be performed sequentially on those positions. The laser light irradiation conditions are not limited as long as full ablation can be caused. As a device for irradiation, a known device can be used.

The above irradiation can cause full ablation at the irradiated position in the resin layer 11, as shown in FIG. 2(d). Specifically, the laser light irradiation evaporates or volatilizes the components constituting the resin layer 11, and the resin layer 11 at the irradiated position disappears. As a result, there is nothing to hold the small work piece 2 on the side of the work handling sheet 1 , and the small work piece 2 falls toward the object 3 . As a result, the work piece 2 ′ existing at the position where the full ablation has occurred can be placed on the object 3 .

In addition, when the resin layer 11 in this embodiment is an adhesive layer composed of the active energy ray-curable adhesive described above, the device manufacturing method described above may further include the following curing step. That is, at least one work piece 2 is attached to the entire resin layer 11 in the laminate in which a plurality of work pieces 2 are held on the surface on the resin layer 11 side, or in the resin layer 11 in the laminate. A curing step may be provided in which the resin layer 11 is wholly or locally cured by irradiating active energy rays to the positions where the resin layer 11 is formed. This curing step may be performed prior to the separation step described above, or may be performed simultaneously with the separation step described above.

Irradiation of active energy rays in the curing step may be performed using a known technique, for example, an ultraviolet irradiation device equipped with a high-pressure mercury lamp or an ultraviolet LED as a light source, or a laser light irradiation device used in the separation step. may When the curing process and the separation process are performed simultaneously, it is preferable to perform the irradiation with the laser light 4 using the laser light irradiation device in combination with the irradiation with the active energy ray.

The device manufacturing method described above may include processes other than the preparation process, placement process, curing process, and separation process. For example, grinding, die bonding, wire bonding, molding, inspection, transfer process, etc. may be performed at any timing between the preparation process and the separation process.

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

In addition, the work handling sheet 1 according to this embodiment can also be used for a method of selectively removing a predetermined small work piece 2 out of a plurality of small work pieces 2 provided on the sheet.

For example, after manufacturing a plurality of light-emitting diodes on the work handling sheet 1 according to this embodiment, the light-emitting diodes are inspected on the sheet. Therefore, only the light-emitting diodes confirmed to be defective can be detached and removed from the work handling sheet 1 by causing full abrasion.

Furthermore, it is also possible to transfer the set of good products from the work handling sheet 1 to the shipping sheet. At this time, when the resin layer 11 is composed of the active energy ray-curable adhesive described above, by irradiating the resin layer 11 with an active energy ray, the adhesive strength of the work handling sheet 1 to the light-emitting diode is increased. can be reduced to allow good collections to transfer well to shipping sheets. After that, by rearranging a separately manufactured non-defective product in the position where the defective product has been removed, it is possible to obtain the work handling sheet 1 on which only the non-defective product is provided.

With the above method of removing defective products by full ablation, there is no need to expand the sheet or pick up defective products, so it is difficult to change the spacing of the light-emitting diodes or cause misalignment. As a result, it can be easily and satisfactorily transferred to the shipping sheet.

The embodiments described above are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiments is meant to include all design changes and equivalents that fall within the technical scope of the present invention.

For example, another layer may be laminated between the resin 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 resin layer 11. . A specific example of the other layer is an adhesive layer. In this case, the above-described separation step and the like can be performed in a state in which the adhesive layer side surface is adhered to a support base (a transparent substrate such as a glass plate).

The adhesive that constitutes the adhesive layer is not particularly limited, but one that is difficult to absorb active energy rays and difficult to block active energy rays is preferable. In this case, when laser light is irradiated through the pressure-sensitive adhesive layer, the laser light easily reaches the resin layer 11, and good full abrasion is likely to occur. Specifically, as the adhesive constituting the adhesive layer, it is preferable to use an adhesive that does not have active energy ray-curable properties, and in particular, an adhesive that does not contain an active energy ray-curable component is preferably used. preferable. By using an adhesive that does not have active energy ray curability, the adhesive layer does not harden even when irradiated with the laser beam, thereby making the work handling sheet 1 from a transparent substrate. It is also possible to prevent peeling that does not occur. Although the thickness of the pressure-sensitive adhesive layer is not particularly limited, it is preferably 5 to 50 μm, for example.

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

[Example 1]
(1) Preparation of Adhesive Composition 70 parts by mass of 2-ethylhexyl acrylate and 30 parts by mass of 2-hydroxyethyl acrylate were polymerized by a solution polymerization method to obtain an acrylic polymer. When the weight average molecular weight (Mw) of this acrylic polymer was measured by the method described later, it was 800,000.

100 parts by mass of the acrylic polymer obtained above (in terms of solid content, hereinafter the same), and 1.5 parts by mass of trimethylolpropane-modified tolylene diisocyanate (manufactured by Tosoh Corporation, trade name "Coronate L") as a cross-linking agent and tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine (hydroxyphenyl 5 parts by mass of a triazine-based ultraviolet absorber, manufactured by BASF, product name "Tinuvin 477") were mixed in a solvent to obtain a coating liquid of an adhesive composition.

(2) Preparation of work handling sheet As a base material, the above-mentioned The coating liquid of the adhesive composition obtained in step (1) was applied, and the obtained coating film was dried by heating. Thereby, a resin layer (adhesive layer) having a thickness of 2 μm was formed on the substrate.

Subsequently, a release sheet (manufactured by Lintec Co., Ltd., product name "SP-PET381031 ”). As a result, a work handling sheet was obtained in which the release sheet, the resin layer and the substrate were laminated in order.

The calculated content of the laser light absorbing component in the formed resin layer was 4.69% by mass. Further, when the content of the laser light absorbing component in the resin layer is X mass % and the thickness of the resin layer is Y μm, the value obtained by dividing X by Y (X/Y) is calculated for this example. , 2.35.

(3) Measurement method of weight average molecular weight The weight average molecular weight (Mw) described above is a weight average molecular weight in terms of standard polystyrene measured using gel permeation chromatography (GPC) under the following conditions (GPC measurement).
<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 super HM-H
TSK gel super H2000
・Measurement solvent: tetrahydrofuran ・Measurement temperature: 40°C

[Examples 2-3 and Comparative Examples 1-2]
A work handling sheet was produced in the same manner as in Example 1 except that the content of the cross-linking agent, the content of the laser light absorbing component, and the thickness of the resin layer were changed as shown in Table 1. Comparative Example 1 is an example in which no laser light absorbing component was used.

Table 1 shows the content (% by mass) of the laser light absorbing component in the resin layer and the content of the laser light absorbing component in the resin layer for Examples 2 and 3 and Comparative Examples 1 and 2. A value obtained by dividing X by Y (X/Y) is also shown, where X mass % is defined as the thickness of the resin layer and Y μm is defined as the thickness of the resin layer.

[Test example] (Evaluation of suitability for laser lift-off)
(1) Chip preparation on work handling sheet (preparation process)
An adhesive surface of a dicing sheet (manufactured by Lintec, product name “D-485H”) was attached to one side of a silicon wafer (#2000, thickness: 350 μm). Subsequently, a ring frame for dicing was adhered to the periphery of the adhesive surface of the dicing sheet (the position not overlapping the silicon wafer). Furthermore, the dicing sheet was cut according to the outer diameter of the ring frame. Thereafter, the silicon wafer was diced into chips having a size of 300 μm×300 μm using a dicing machine (manufactured by Disco, product name “DFD6362”). After that, the dicing sheet was irradiated with ultraviolet light (illuminance: 230 mW/cm ² , light amount: 190 mJ/cm ² ). As a result, a laminate having a plurality of chips 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 surface thus exposed was bonded to the surface on which the plurality of chips of the laminate obtained as described above existed. . After that, 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 to obtain a laminate having a plurality of chips provided on the work handling sheet.

(2) Separation of chips by laser light irradiation (separation process)
For the laminate in which a plurality of chips are provided on the work handling sheet obtained in the above step (1), a laser beam is applied to each chip through the work handling sheet using a laser light irradiation device. was irradiated.

Specifically, the chip was irradiated with a laser beam with a wavelength of 355 nm through the work handling sheet using a laser beam irradiation device (manufactured by Keyence Corporation, product name "MD-U1000C"). The irradiation was carried out by spirally scanning the laser light spot from the periphery of the chip toward the center so that the entire surface of the chip was irradiated. At this time, the diameter of the laser light spot was 20 μm, the frequency was 40 kHz, the scanning speed was 500 mm/s, and the irradiation amount was 50 μJ/shot. Also, 100 chips (a group of 10 vertical chips by 10 horizontal chips) were selected from a plurality of chips and irradiated.

(3) Confirmation of Disappearance of Resin Layer and Chip Separation Whether or not the resin layer was dissipated was confirmed using a laser microscope for the positions irradiated as described above. Then, disappearance of the resin layer was evaluated based on the following criteria. Table 1 shows the results.
◯: Sufficiently disappeared at all positions.
×: There was a portion where the disappearance was insufficient.

Furthermore, the presence or absence of detachment of the chip from the work handling sheet was confirmed, and laser lift-off aptitude was evaluated based on the following criteria. Table 1 shows the results.
Good: Detachment occurred for all 100 chips.
x: The number of chips where detachment occurred was less than 100.

As is clear from Table 1, the work handling sheets produced in Examples were excellent in suitability for laser lift-off.

The work handling sheet of the present invention can be suitably used for manufacturing a display or the like having micro light-emitting diodes as pixels.

REFERENCE SIGNS LIST 1 work handling sheet 11 resin layer 12 base material 2, 2' work piece 3 object 4 laser beam

Claims

A work handling sheet comprising a base material and a resin layer laminated on one side of the base material and capable of holding a small work piece,
The resin layer contains 10% by mass or more of a laser light absorbing component having an absorptive property with respect to the wavelength of the laser light,
A work handling sheet, wherein the resin layer is fully ablated by irradiation with the laser beam.
A work handling sheet comprising a base material and a resin layer laminated on one side of the base material and capable of holding a small work piece,
The resin layer contains a laser light absorbing component having an absorptive property with respect to the wavelength of the laser light,
When the content of the laser light absorbing component in the resin layer is X mass % and the thickness of the resin layer is Y μm, the value obtained by dividing X by Y (X/Y) is 2.0 or more. A work handling sheet characterized by:
The work handling sheet according to claim 1 or 2, wherein the laser light absorbing component is at least one of an ultraviolet absorber and a photopolymerization initiator.
The work handling sheet according to claim 3, wherein the ultraviolet absorber is an organic compound.
The work handling sheet according to claim 3 or 4, wherein the ultraviolet absorber is a compound having one or more heterocycles.
The ultraviolet absorber has at least one of a carbocyclic ring and a heterocyclic ring,
6. The work handling sheet according to any one of claims 3 to 5, wherein all of the carbon rings and heterocycles of the ultraviolet absorber are monocyclic rings.
The work handling sheet according to any one of claims 3 to 6, 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 7, wherein the resin layer is an adhesive layer.
The work handling sheet according to claim 8, wherein the adhesive constituting the adhesive layer is an acrylic adhesive.
The work handling sheet according to any one of claims 1 to 9, wherein the laser light has a wavelength in the ultraviolet region.
An arbitrary work piece out of a plurality of work pieces held on a surface of the resin layer opposite to the base material is selectively removed from the resin layer by full ablation locally generated in the resin layer. The work handling sheet according to any one of claims 1 to 10, which is used for separating into.
12. The work piece according to claim 11, wherein the work piece is obtained by singulating a work held on a surface of the resin layer opposite to the base material on the surface of the resin layer. work handling sheet.
The work handling sheet according to claim 11 or 12, wherein the small work pieces are at least one selected from semiconductor parts and semiconductor devices.
The work handling sheet according to any one of claims 11 to 13, wherein the work pieces are light emitting diodes selected from mini light emitting diodes and micro light emitting diodes.
A preparation step of preparing a laminate in which a plurality of small work pieces are held on the resin layer side surface of the work handling sheet according to any one of claims 1 to 14;
an arrangement step of arranging the laminate so that the surface of the laminate on the side of the small work piece faces an object capable of receiving the small work piece;
By irradiating a laser beam to a position where at least one of the work pieces is attached in the resin layer of the laminate to cause full ablation at the irradiated position in the resin layer, the and a separation step of separating the small work piece existing at a position where full ablation has occurred from the work handling sheet and placing the small work piece on the object.
16. The work piece according to claim 15, wherein in the preparation step, the work piece held on the surface of the resin layer opposite to the base material is singulated on the surface to obtain the work pieces. A method for manufacturing the described device.
The device manufacturing method according to claim 15 or 16, wherein the work piece is at least one selected from semiconductor parts and semiconductor devices.
The light-emitting device according to any one of claims 15 to 17, wherein a light-emitting diode selected from mini-light-emitting diodes and micro-light-emitting diodes is used as the work piece to manufacture a light-emitting device comprising a plurality of the light-emitting diodes. Device manufacturing method.
The device manufacturing method according to claim 18, wherein the light emitting device is a display.