JP2023097043A - Work handling sheet and device manufacturing method - Google Patents

Abstract

To provide a work handling sheet capable of satisfactorily handling even a relatively large workpiece piece, and a device manufacturing method using the work handling sheet.SOLUTION: A work handling sheet 1 includes: a base material 12; and an interface ablation layer 11 that is laminated on one surface side of the base material 12, capable of holding a work piece, and performs interface ablation by irradiation with a laser beam. A surface opposite to the base material 12 of the interface ablation layer 11 is an uneven surface having unevenness.SELECTED DRAWING: Figure 1

Description

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.

Semiconductor wafers made of silicon, gallium arsenide, etc., and various types of packages are manufactured in a state of large diameter. is transferred to the mounting process, which is the process of . At this time, the workpiece such as a semiconductor wafer is subjected to processing such as back grinding, dicing, cleaning, drying, expanding, picking up, and mounting while being attached to a semiconductor processing sheet having a base material and an adhesive layer. done.

In the above-described pick-up and mounting steps, the semiconductor chips on the semiconductor processing sheet are individually picked up using a suction collet and arranged at predetermined positions. At this time, the semiconductor chips may be separated from each other by pushing up the semiconductor chips from the back surface of the semiconductor processing sheet using a needle or by expanding the semiconductor processing sheet.

By the way, in recent years, in the development of displays using micro light-emitting diodes, the use of laser light irradiation for arranging individual micro light-emitting diodes on a substrate has been studied. For example, in Patent Document 1, a plurality of micro light-emitting diodes are held on a support via a predetermined layer, and then the layer is irradiated with laser light to ablate the layer at the irradiated position. is produced, and a method of mounting micro-light-emitting diodes separated (laser lift-off) from a support on a wiring substrate is being studied. 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

In general, semiconductor chips obtained by dicing a semiconductor wafer are larger in size than micro light emitting diodes. Therefore, even if the laser lift-off technique described above is used as a substitute for picking up and mounting semiconductor wafers, there is a problem that the semiconductor chips cannot be separated satisfactorily.

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 a relatively large piece of work well, and a device manufacturing method using the work handling sheet. intended to

In order to achieve the above object, firstly, the present invention provides a base material, and an interface ablation layer laminated on one side of the base material, capable of holding a small work piece, and ablating the interface by laser light irradiation. , wherein the surface of the interfacial ablation layer opposite to the base material is an uneven surface having unevenness (Invention 1).

In the work handling sheet according to the above invention (invention 1), the surface of the interfacial abrasion layer is uneven, so that the unevenness of the uneven surface acts as a starting point for separating the work pieces during interfacial abrasion. It works well and allows good separation even with relatively large work pieces.

In the above invention (invention 1), the uneven surface is preferably a matte surface (invention 2).

In the above invention (Invention 2), it is preferable that the ratio (Rp/Ra) of the maximum peak height Rp to the arithmetic mean roughness Ra of the matte surface is 5 or more (Invention 3).

In the above invention (invention 1), it is preferable that the uneven surface is a surface having a plurality of grooves formed in a grid pattern (invention 4).

In the above invention (invention 4), the width of the groove is 10 μm or more and 120 μm or less, the depth of the groove is 5 μm or more and 50 μm or less, and two adjacent grooves in the group of parallel grooves are arranged in parallel. The center-to-center distance of the grooves is preferably 50 μm or more and 700 μm or less (Invention 5).

In the above inventions (Inventions 1 to 5), the work handling sheet includes a release sheet laminated on the surface of the interfacial ablation layer opposite to the base material, and the surface of the release sheet on the interfacial ablation layer side is: It is preferable to have unevenness corresponding to the uneven surface of the interface ablation layer (Invention 6).

In the above inventions (inventions 1 to 6), the interface abrasion layer is preferably an adhesive layer (invention 7).

In the above inventions (inventions 1 to 7), the interface abrasion layer preferably contains an ultraviolet absorber (invention 8).

In the above inventions (inventions 1 to 8), the laser light preferably has a wavelength in the ultraviolet region (invention 9).

In the above inventions (inventions 1 to 9), it is preferable that when the interface ablation is caused in the interface ablation layer, a blister is formed at the position where the interface ablation occurs (invention 10).

In the above inventions (inventions 1 to 10), by interfacial ablation locally generated in the interfacial ablation layer, one of the plurality of work pieces held on the surface of the interfacial ablation layer opposite to the base material It is preferably used to selectively separate any work pieces from the interfacial ablation layer (invention 11).

In the above invention (invention 11), the work pieces are obtained by singulating a work held on a surface of the interfacial ablation layer opposite to the base material into pieces on the surface. is preferred (Invention 12).

Secondly, the present invention provides a work handling sheet comprising a base material and an interface ablation layer laminated on one side of the base material and having an uneven surface on the opposite side of the base material. a preparation step of preparing a laminate in which a plurality of small work pieces are held on a surface facing the ablation layer; and irradiating a laser beam to a position where at least one of the work pieces is attached in the interfacial ablation layer of the laminate, so that the ablation layer in the interfacial ablation layer a separation step of causing interfacial ablation at the irradiated position to separate the work piece present at the position where the interfacial ablation occurred from the work handling sheet and placing the work piece on the object; (Invention 13).

In the above invention (invention 13), in the preparation step, the workpiece held on the surface of the interfacial ablation layer opposite to the substrate is singulated on the surface to obtain the workpiece pieces. (Invention 14).

The work handling sheet according to the present invention can handle even relatively large pieces of work satisfactorily, and according to the device manufacturing method according to the present invention, devices having 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; FIG. 4 is a cross-sectional view illustrating the state of blisters and reaction regions generated by laser light irradiation. FIG. 4 is an enlarged view showing how a work piece is separated from a work handling sheet by interface abrasion.

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. The work handling sheet 1 shown in FIG. 1 comprises a substrate 12 and an interfacial ablation layer 11 laminated on one side of the substrate 12 .

In the work handling sheet 1 according to this embodiment, the interface ablation 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 interface ablation layer 11 opposite to the substrate 12 as it is.

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

Further, the interface ablation layer 11 in this embodiment is subjected to interface ablation by irradiation with laser light. That is, the interface ablation layer 11 is locally ablated at the interface in the region irradiated with the laser beam. The laser light is not particularly limited as long as it can cause interfacial ablation, and may be a laser light having any wavelength in the ultraviolet region, the visible light region, and the infrared region. is preferred.

In this specification, interfacial ablation means that part of the components constituting the interfacial ablation layer 11 evaporates or volatilizes due to the energy of the laser beam, and the resulting gas is the interface between the interfacial ablation layer 11 and the substrate 12. It refers to the formation of air gaps (blister). In this case, the shape of the interfacial ablation layer 11 is changed by the blister, and the small work piece is peeled off from the interfacial ablation layer 11, resulting in separation of the work piece.

In the work handling sheet 1 according to this embodiment, the surface of the interface abrasion layer 11 opposite to the substrate 12 is an uneven surface having unevenness. FIG. 1 depicts a state in which a plurality of grooves 13 are provided on the surface of the interface ablation layer 11 opposite to the substrate 12 as an example of unevenness. In the work handling sheet 1 according to the present embodiment, the surface in contact with the small work piece is uneven, so that the small work piece can be separated satisfactorily when interfacial abrasion occurs.

The reason why the work pieces can be separated well by the uneven surface is considered as follows. However, this does not exclude possibilities other than the following reasons. When the surface in contact with the work piece is an uneven surface, as shown in FIG. 4A, the end of the work piece (in FIG. In (a), there is a high possibility that it will overlap with the groove 13). It is considered that the adhesion between the work piece and the interfacial ablation layer 11 is locally low at the end overlapping with the unevenness. Then, in this state, when interfacial ablation is generated to generate a force to separate the small work piece, as shown in FIG. This triggers separation of the entire work pieces.

In general, the larger the size of the work piece, the larger the contact area between the work piece and the interfacial ablation layer 11, which tends to make it more difficult for the work piece to separate due to interfacial abrasion. However, in the work handling sheet 1 according to the present embodiment, since the work handling sheet 1 has the uneven surface as described above, the small work piece is effectively separated from the end portion overlapping the unevenness. Therefore, with the work handling sheet 1 according to this embodiment, even if the small work pieces are relatively large, they can be separated satisfactorily.

1. Interfacial Ablation Layer The interfacial ablation layer 11 in this embodiment is capable of holding a work piece, and has the property of being interfacially ablated by laser light irradiation, and the surface opposite to the base material 12 has unevenness. As long as it has an uneven surface, its specific configuration and composition are not particularly limited.

(1) Unevenness The unevenness on the uneven surface may be regular or irregular. Examples of the uneven surface include a matte surface formed by matte finish, a surface having a plurality of grooves 13, and the like. An example of the surface having a plurality of grooves 13 is a surface having a plurality of grooves 13 formed in a grid pattern.

When the uneven surface is a matte surface, the ratio of the maximum peak height Rp to the arithmetic mean roughness Ra (Rp/Ra) is preferably 5 or more, particularly preferably 6 or more. When the ratio (Rp/Ra) is 5 or more, it becomes easier to effectively separate the work pieces by interfacial ablation. The ratio (Rp/Ra) is preferably 10 or less, particularly preferably 8 or less, and more preferably 7 or less. When the ratio (Rp/Ra) is 10 or less, the adhesion between the interface ablation layer 11 and the small work pieces is facilitated, and separation of the work pieces at an unintended stage is easily suppressed. The details of the method for measuring the arithmetic mean roughness Ra and the maximum peak height Rp are as described in the Examples section below.

The arithmetic mean roughness Ra is preferably 0.04 μm or more, particularly preferably 0.05 μm or more, and further preferably 0.06 μm or more. The arithmetic mean roughness Ra is preferably 0.3 μm or less, particularly preferably 0.15 μm or less, and further preferably 0.1 μm or less. When the arithmetic mean roughness Ra is within the above range, the range of the ratio (Rp/Ra) described above can be easily satisfied.

The maximum peak height Rp is preferably 0.1 μm or more, particularly preferably 0.3 μm or more. Also, the maximum peak height Rp is preferably 1.0 μm or less, particularly preferably 0.8 μm or less. When the maximum peak height Rp is within the above range, it becomes easy to satisfy the range of the ratio (Rp/Ra) described above.

When the uneven surface is a surface having a plurality of grooves 13, the width of the grooves 13 is preferably 10 μm or more, particularly preferably 20 μm or more. Moreover, the width of the groove 13 is preferably 120 μm or less, particularly preferably 50 μm or less.

Further, the depth of the grooves 13 is preferably 5 μm or more, particularly preferably 10 μm or more. Moreover, the depth of the groove 13 is preferably 50 μm or less, particularly preferably 30 μm or less.

Furthermore, when the above-described surface having a plurality of grooves 13 is a surface having a plurality of grooves 13 formed in a grid pattern, the center-to-center distance between two adjacent grooves 13 in a group of parallel grooves 13 is , preferably 50 μm or more, particularly preferably 100 μm or more. Also, the center-to-center distance is preferably 700 μm or less, particularly preferably 300 μm or less.

When the width and depth of the grooves 13 and the center-to-center distance between two adjacent grooves 13 are within the above ranges, it becomes easier to effectively separate the work pieces by interface abrasion. The details of the method for measuring the width, depth, and center-to-center distance described above are as described in the Examples section below.

Moreover, the cross-sectional shape of the groove 13 is not limited to the inverted triangle shown in FIG. 1, and may be rectangular, semicircular, or the like.

(2) Adhesive With respect to the composition of the interface abrasion layer 11, from the viewpoint that it is easy to exhibit the property of being able to hold a small piece of work, as described above, an adhesive is included as one of the constituent components. is preferred.

The adhesive is not particularly limited as long as it can exert sufficient holding power (adhesive power) to an adherend such as a work piece. 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 easy to obtain a stable coating film of the interface abrasion layer. 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).

The glass transition temperature (Tg) of the acrylic polymer (A) is preferably −70° C. or higher, 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 monomer 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 below to form a three-dimensional network structure, which facilitates enhancing the cohesiveness of the interfacial abrasion layer. . 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 modulus of the interfacial ablation layer 11 to 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 interfacial abrasion 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.

(3) Ultraviolet absorber The interface ablation layer 11 preferably contains an ultraviolet absorber. The presence of the ultraviolet absorber in the interfacial ablation layer 11 improves the efficiency with which the interfacial ablation layer 11 receives energy from laser light. This effectively causes interfacial ablation and facilitates better separation of the retained work piece from the interfacial ablation 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. As a result, the accuracy is improved, and damage to the device or the like due to excessive laser beam irradiation can be prevented.

When the interfacial abrasion layer 11 contains an ultraviolet absorber together with the adhesive described above, the interfacial abrasion layer 11 is preferably made of an adhesive composition containing the ultraviolet absorber.

The type of ultraviolet absorber in this embodiment is not particularly limited. The ultraviolet absorber in the present embodiment may be an organic compound or an inorganic compound, but from the viewpoint of facilitating good interfacial abrasion, it is preferably an organic compound.

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 UV absorbers described above, hydroxyphenyltriazine-based UV absorbers and benzophenone-based UV absorbers have good absorbency in the third harmonic (355 nm) of YAG and are likely to cause good interfacial abrasion. 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.

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

Moreover, when the interfacial abrasion layer 11 in this embodiment is formed from an adhesive composition, which will be described later, the ultraviolet absorber may be blended in this adhesive composition. In that case, the amount of the ultraviolet absorber in the adhesive composition is preferably 1% by mass or more, more preferably 2% by mass or more, and particularly preferably 3% by mass or more, Furthermore, it is preferably 5% by mass or more. When the blending amount of the ultraviolet absorber is 1% by mass or more, the interfacial ablation layer 11 efficiently absorbs the laser light, thereby facilitating good interfacial abrasion. In addition, the amount of the ultraviolet absorber in the adhesive composition is preferably 75% by mass or less, more preferably 60% by mass or less, particularly preferably 50% by mass or less, and further is preferably 20% by mass or less. When the blending amount of the ultraviolet absorber is 75% by mass or less, the pressure-sensitive adhesive to be obtained easily exhibits the desired pressure-sensitive adhesive strength.

(4) Photopolymerization Initiator The interface ablation layer 11 preferably contains a photopolymerization initiator. The presence of the photopolymerization initiator in the interfacial ablation layer 11 also improves the efficiency with which the interfacial ablation layer 11 receives energy from laser light. This effectively causes interfacial ablation and facilitates better separation of the retained work piece from the interfacial ablation 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. As a result, the accuracy is improved, and damage to the device or the like due to excessive laser beam irradiation can be prevented.

When the interfacial abrasion layer 11 contains a photopolymerization initiator together with the adhesive described above, the interfacial abrasion layer 11 preferably comprises an adhesive composition containing the photopolymerization initiator.

The type of photopolymerization initiator in this embodiment 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.

The content of the photopolymerization initiator in the interface ablation layer 11 in the present embodiment is preferably 1.8% by mass or more, particularly preferably 3.0% by mass or more, and further preferably 5.0% by mass. % or more. When the content of the photopolymerization initiator is 1.8% by mass or more, the interface ablation layer 11 efficiently absorbs the laser light, thereby favorably facilitating interface ablation. Further, the content of the photopolymerization initiator in the interface ablation layer 11 in this embodiment is preferably 40.0% by mass or less, particularly preferably 30.0% by mass or less, and further preferably 25.0% by mass or less. It is preferably 0% by mass or less. When the content of the photopolymerization initiator is 40.0% by mass or less, the viscosity of the material for forming the interfacial ablation layer 11 becomes appropriate, and it becomes easy to ensure good film formability.

Moreover, when the interfacial abrasion layer 11 in the present embodiment is formed from an adhesive composition, which will be described later, the photopolymerization initiator may be blended into this adhesive composition. In that case, the amount of the photopolymerization initiator in the adhesive composition is preferably 1.8% by mass or more, particularly preferably 3.0% by mass or more, and further preferably 5.0% by mass. % or more. When the blending amount of the photopolymerization initiator is 1.8% by mass or more, the interface ablation layer 11 efficiently absorbs the laser light, thereby favorably facilitating interface ablation. The amount of the photopolymerization initiator in the adhesive composition is preferably 40.0% by mass or less, particularly preferably 30.0% by mass or less, and further preferably 25.0% by mass. The following are preferable. When the blending amount of the photopolymerization initiator is 40.0% by mass or less, the pressure-sensitive adhesive to be obtained easily exhibits desired pressure-sensitive adhesive strength.

(5) Thickness of interface ablation layer The thickness of the interface ablation layer 11 in the present embodiment is preferably 3 µm or more, particularly preferably 20 µm or more, further preferably 25 µm or more. When the thickness of the interfacial ablation layer 11 is 3 μm or more, when interfacial ablation is caused, it becomes easy to suppress rupture or breakage of the interfacial ablation layer 13 due to blisters, and it is easy to separate the work pieces satisfactorily. Become. Further, the thickness of the interfacial ablation layer 11 is preferably 100 μm or less, particularly preferably 50 μm or less, further preferably 40 μm or less. When the thickness of the interfacial ablation layer 11 is 100 μm or less, the interfacial ablation layer 11 is easily deformed when the interfacial ablation is caused, and as a result, it becomes easy to separate the workpiece pieces satisfactorily. .

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.

The surface of the base material 12 in this embodiment may be subjected to a surface treatment such as an oxidation method or roughening method, or a primer treatment for the purpose of improving adhesion to the interface ablation layer 11 . Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment. 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 interfacial ablation layer 11 contains a material that is cured by active energy rays, the substrate 12 preferably has transparency to active energy rays.

A method for manufacturing the base material 12 in the present 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 substrate 12 in the present 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 The work handling sheet 1 according to the present embodiment may include a release sheet laminated on the surface of the interface abrasion layer 11 opposite to the substrate 12 . In particular, when the interfacial abrasion layer 11 contains an adhesive as one of its constituent components, a release sheet is laminated for the purpose of protecting the interfacial abrasion layer 11 until it is attached to the work piece. is preferred.

When the work handling sheet 1 according to the present embodiment includes a release sheet, the surface of the release sheet on the interface abrasion layer 11 side preferably has unevenness corresponding to the uneven surface of the interface abrasion layer 11 described above. As a result, the shape of the uneven surface of the interfacial ablation layer 11 can be maintained well until the work piece is laminated on the interfacial ablation layer 11 . Further, as will be described later, when the interfacial ablation layer 11 is formed on a release sheet, it is also possible to form the uneven surface of the interfacial ablation layer 11 by utilizing the uneven shape of the release sheet.

The configuration of the release sheet is arbitrary, and examples thereof include paper or plastic films subjected to release treatment with a release agent or the like. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, a silicone-based release agent, a fluorine-based release agent, a long-chain alkyl-based release agent, or the like can be used.

The unevenness of the release sheet can be formed by a known method. For example, after melt-extrusion laminating a resin on the surface of paper or a plastic film, the resin is passed through a cooling roll having unevenness on the surface to transfer the unevenness of the cooling roll to the surface of the resin layer formed by curing the resin. be able to. A release sheet can be obtained by subjecting the thus-obtained base material having surface irregularities to the release treatment described above, if necessary.

In addition, a release sheet having unevenness can be obtained by performing embossing treatment after performing release treatment on a predetermined base material.

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

4. Other Configurations In the work handling sheet 1 according to the present embodiment, an adhesive layer may be laminated on the surface of the interface abrasion layer 11 opposite to the substrate 12 . In the sheet, a workpiece is attached to the surface of the adhesive layer opposite to the surface ablation layer 11, and the adhesive layer is diced together with the workpiece to form workpiece pieces in which the individualized adhesive layer is laminated. can be obtained. 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

Further, in the work handling sheet 1 according to the present embodiment, a protective film-forming layer may be laminated on the surface of the interface abrasion 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 surface of the protective film-forming layer 11, and the protective film-forming layer is diced together with the work. A laminated 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 interfacial ablation layer 11 may be directly formed on the base material 12, or the interfacial ablation layer 11 may be formed on a release sheet or a process sheet and then transferred onto the base material 12. may However, from the viewpoint that the uneven surface of the interfacial ablation layer 11 is easy to form, the interfacial ablation layer 11 is formed on a release sheet or a process sheet having unevenness corresponding to the uneven surface, and the interfacial ablation layer 11 is used as the base material. 12 is preferred.

When the interfacial ablation layer 11 contains an adhesive as one of its constituent components, the interfacial ablation layer 11 can be formed by a known method. For example, a coating liquid containing an adhesive composition for forming the interfacial ablation layer 11 and optionally a solvent or 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, by drying the obtained coating film, the interfacial abrasion layer 11 can be formed.

The application of the coating liquid described above can be performed by a known method such as a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, or the like. The properties of the coating liquid are not particularly limited as long as it is possible to apply the coating liquid. be. Further, when the interface abrasion layer 11 is formed on the release sheet, the release sheet may be peeled off as a process material, or may protect the interface abrasion layer 11 until it is attached to the adherend. .

When the adhesive composition for forming the interfacial ablation layer 11 contains the above-described cross-linking agent, by changing the drying conditions (temperature, time, etc.) or by separately providing heat treatment, It is preferable to promote a cross-linking reaction between the polymer component in the coating film and the cross-linking agent to form a cross-linked structure with a desired existence density in the interfacial ablation 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, for example, by leaving it in an environment of 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 interface ablation layer 11 is efficiently ablated by laser light irradiation. It can be separated towards a predetermined position with precision.

As an example of the method of using the work handling sheet 1 according to the present embodiment, the surface of the interface ablation layer 11 is held on the surface opposite to the substrate 12 by the interface ablation locally caused in the interface ablation layer 11. A method of use is to selectively separate an arbitrary work piece out of a plurality of work pieces from the interfacial ablation layer 11 .

In the method of use described above, the plurality of work pieces held on the interfacial ablation layer 11 are the works (materials of the work pieces) held on the surface of the interfacial ablation layer 11 opposite to the substrate 12 . It may be obtained by singulating on the surface. That is, the work piece may be obtained by dicing the work on the interfacial ablation layer 11 . Alternatively, the small work piece may be formed independently of the work handling sheet 1 according to the present embodiment and placed on the interfacial ablation layer 11 .

In addition, when the work handling sheet 1 according to this embodiment includes the adhesive layer and the protective film forming layer described above, it is preferable to dicing these layers and the work on the interface ablation 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 0.025 mm ² or more, particularly 0.01 mm ² or more, when viewed from above. is preferred. In addition, the work piece preferably has an area of 10000 mm ² or less, particularly preferably 2000 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 25 μm or more, particularly preferably 30 μm or more, and further preferably 50 μm or more. preferable. Also, the minimum side is preferably 100 mm or less, particularly preferably 90 mm or less. Specific examples of the dimensions of the rectangular work pieces include 20 mm×50 mm, 10 mm×10 mm, 5 mm×5 mm, and 1 mm×1 mm.

As described above, in the work handling sheet 1 according to the present embodiment, the surface of the interface ablation layer 11 is uneven, so that even relatively large work pieces as described above can be separated satisfactorily. It can be performed.

Examples of small work pieces include semiconductor members such as semiconductor wafers and semiconductor packages, and glass members such as glass plates. Also, the work piece may be a semiconductor component or semiconductor device such as a micro light emitting diode, a mini light emitting diode, a power device, MEMS (Micro Electro Mechanical Systems), a controller chip, or the like.

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 step, as shown in FIG. 2A, a laminate is prepared in which a plurality of small work pieces 2 are held on the surface of the work handling sheet 1 according to the present embodiment on the side of the interface ablation layer 12. . 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 interfacial ablation layer 11 side may be individually placed on the surface. It may be prepared by dicing (ie, dicing). The dicing can be performed by a known method.

As described above, the shape and size of the work piece 2 are not particularly limited, and the preferred sizes are also as described above. Specific examples of the work pieces 2 include those described above, and particularly semiconductor members such as semiconductor wafers and semiconductor packages.

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 board provided with wiring is preferably used.

Then, in the separation step, first, as shown in FIG. 2(c), a laser beam is irradiated to the position where at least one work piece 2 is attached in the interface ablation layer 11 of the laminate. 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 irradiation conditions of the laser light are not limited as long as it is possible to cause interfacial ablation. As a device for irradiation, a known device can be used.

The irradiation can cause interfacial ablation at the irradiated locations in the interfacial ablation layer 11, as shown in FIG. 2(d). Specifically, the irradiation of the laser light evaporates or volatilizes the components forming the region in the interface ablation layer 11 in the vicinity of the substrate 12 to form the reaction region 14 . Then, the gas generated by the evaporation or volatilization accumulates between the substrate 11 and the reaction area 14 to form the blister 5 . Due to the formation of the blisters 5 , the interfacial ablation layer 11 is locally deformed at the position of the work piece 2 ′, and the work piece 2 ′ separates so as to be peeled off from the interfacial ablation layer 11 . As described above, the work piece 2 ′ existing at the position where the interface abrasion has occurred can be placed on the object 3 .

Incidentally, the reaction region 14 and the blisters 5 generated by the irradiation of the laser light usually remain even after the work pieces 2' are separated. FIG. 3 shows how the work pieces 2 are separated by sequentially irradiating laser light. The previous states (right two) are shown. As shown, the blister 5 after detachment is typically in a slightly more deflated state than the blister 5 during detachment.

When the interfacial abrasion layer 11 contains an active energy ray-curable adhesive as one of its constituent components, the interfacial abrasion layer 11 may be cured by irradiation with the laser beam described above. The curing reduces the adhesion of the interfacial ablation layer 11 to the work piece 2, and combined with the above-described interfacial ablation action, the work piece 2' may be separated satisfactorily. Alternatively, the interface ablation layer 11 may be irradiated with an active energy ray different from the irradiation with the laser beam described above, thereby reducing the adhesive force to the work piece 2 . Such active energy ray irradiation may be performed before or after laser light irradiation. The active energy ray irradiation may be performed locally on the interface ablation layer 11 or may be performed on the entire surface of the interface ablation layer 11 . The irradiation conditions and irradiation apparatus for the active energy ray irradiation described above are not particularly limited, and known conditions and known apparatuses can be used.

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.

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 embodiment is meant to include all design changes and equivalents that fall within the technical scope of the present invention.

For example, another layer is laminated between the interfacial ablation layer 11 and the base material 12 in the work handling sheet 1 according to the present embodiment, or on the surface of the base material 12 opposite to the interfacial ablation layer 11. good too. 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).

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

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

[Preparation Example 2]
80 parts by mass of 2-ethylhexyl acrylate and 20 parts by mass of 2-hydroxyethyl acrylate were polymerized by a solution polymerization method to obtain an acrylic polymer. Subsequently, 2-methacryloyloxyethyl isocyanate (MOI) is added in an amount corresponding to 80 mol% with respect to 2-hydroxyethyl acrylate constituting the acrylic polymer, and dibutyltin dilaurate as a tin-containing catalyst. (DBTDL) was added in an amount of 0.025 parts by mass based on 100 parts by mass of the acrylic polymer. After that, reaction was carried out at 50° C. for 24 hours to obtain an acrylic polymer in which an active energy ray-curable group was introduced into the side chain. When the weight average molecular weight of the acrylic polymer was measured by the method described above, it was 600,000. Let the said acrylic polymer be the acrylic polymer B.

[Example 1]
(1) Preparation of release sheet After melt-extrusion lamination of polyethylene resin (manufactured by Tosoh Corporation, product name “Petrothene 217”) on both sides of high-quality paper with a basis weight of 110 g / m ² , the surface is continuously roughened. A polyethylene layer (thickness: 30 μm) with a rough surface (mat surface), fine paper, and a polyethylene layer with a flat surface ( A laminate having a thickness of 30 μm) was obtained.

A coating liquid of a release agent composition containing a silicone-based release component was applied onto the matte surface of the obtained laminate to form a coating film. Then, the coating film was heated at 140° C. for 1 minute to form a release agent layer with a thickness of 0.5 μm. As a result, a release sheet having an uneven release surface (mat surface) was obtained.

(2) Preparation of adhesive composition Acrylic polymer A 100 parts by mass (in terms of solid content, the same applies hereinafter) obtained in Preparation Example 1 above, and trimethylolpropane-modified tolylene diisocyanate (manufactured by Tosoh Corporation, 0.94 parts by mass (trade name “Coronate L”) and tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}] as an ultraviolet absorber. -1,3,5-triazine (hydroxyphenyltriazine-based UV absorber, manufactured by BASF, product name "Tinuvin477") 2.0 parts by mass were mixed in a solvent to obtain a coating liquid of an adhesive composition. . The interfacial abrasion layer (adhesive layer) formed using the coating liquid of the adhesive composition does not contain an acryloyl group-containing component, and therefore does not have active energy ray curability.

(3) Formation of interfacial abrasion layer (adhesive layer) The coating solution of the adhesive composition obtained in step (2) is applied to the release surface of the release sheet prepared in step (1) above, The resulting coating film was dried by heating. As a result, a laminate was obtained in which an interface abrasion layer having a thickness of 30 μm formed by drying the coating film and a release sheet were laminated.

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

When the release sheet was peeled off from the obtained work handling sheet, the exposed surface of the interface abrasion layer became a matte surface corresponding to the release surface of the release sheet. The arithmetic mean roughness Ra (μm) and the maximum peak height Rp (μm) of the matte surface were measured using a stylus-type surface roughness meter (manufactured by Mitutoyo, product name "Surftest SV3000"). They were 0.08 μm and 0.50 μm, respectively. From these measurement results, the ratio of the maximum peak height Rp to the arithmetic mean roughness Ra (Rp/Ra) was calculated to be 6.25.

Here, the weight average molecular weight (Mw) described above is a weight average molecular weight in terms of standard polystyrene measured under the following conditions using gel permeation chromatography (GPC).
<Measurement conditions>
・ Measuring device: HLC-8320 manufactured by Tosoh Corporation
・ GPC column (passed in the following order): TSK gel superH-H manufactured by Tosoh Corporation
TSK gel super HM-H
TSK gel super H2000
・Measurement solvent: tetrahydrofuran ・Measurement temperature: 40°C

[Example 2]
A work handling sheet was obtained in the same manner as in Example 1, except that the content of the ultraviolet absorber was changed.

[Example 3]
2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-phenyl)butan-1-one (manufactured by IGM Resins Co., Ltd., A work handling sheet was obtained in the same manner as in Example 1, except that a coating solution of an adhesive composition prepared by further adding 3.0 parts by mass of product name "Omnirad 379") was used.

The interface ablation layer (adhesive layer) formed using the coating liquid of the adhesive composition also does not contain an acryloyl group-containing component, and therefore does not have active energy ray curability.

[Example 4]
A mixture obtained by mixing the acrylic polymer A obtained in Preparation Example 1 and the acrylic polymer B obtained in Preparation Example 2 at a solid content mass ratio of 1:2 was added to the acrylic polymer. A work handling sheet was obtained in the same manner as in Example 1, except that it was used in place of Union A.

In addition, the interface ablation layer (adhesive layer) in the work handling sheet contains a component containing an acryloyl group (acrylic polymer B), but does not contain a photopolymerization initiator, thereby improving active energy ray curability. It does not have.

[Example 5]
2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-phenyl)butane as a photopolymerization initiator for 100 parts by mass of the mixture of acrylic polymer A and acrylic polymer B -1-one (manufactured by IGM Resins, product name "Omnirad 379") 3.0 parts by mass was further added to use a coating liquid of an adhesive composition prepared in the same manner as in Example 4. Got a handling sheet.

In addition, since the interfacial abrasion layer (adhesive layer) formed using the coating liquid of the adhesive composition contains an acryloyl group-containing component (acrylic polymer B) and a photopolymerization initiator, the active energy It has linear curability.

[Example 6]
A work handling sheet was obtained in the same manner as in Example 1, except that the acrylic polymer B obtained in Preparation Example 2 was used in place of the acrylic polymer A.

In addition, the interface ablation layer (adhesive layer) in the work handling sheet contains a component containing an acryloyl group (acrylic polymer B), but does not contain a photopolymerization initiator, thereby improving active energy ray curability. It does not have.

[Example 7]
2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-phenyl)butan-1-one (manufactured by IGM Resins Co., Ltd., A work handling sheet was obtained in the same manner as in Example 6, except that a coating solution of an adhesive composition prepared by further adding 3.0 parts by mass of product name "Omnirad 379") was used.

In addition, since the interfacial abrasion layer (adhesive layer) formed using the coating liquid of the adhesive composition contains an acryloyl group-containing component (acrylic polymer B) and a photopolymerization initiator, the active energy It has linear curability.

[Example 8]
A work handling sheet was obtained in the same manner as in Example 3, except that no ultraviolet absorber was used.

The interfacial abrasion layer (adhesive layer) formed using the coating liquid of the adhesive composition does not contain an acryloyl group-containing component, and therefore does not have active energy ray curability.

[Example 9]
A work handling sheet was obtained in the same manner as in Example 5, except that no ultraviolet absorber was used.

In addition, since the interfacial abrasion layer (adhesive layer) formed using the coating liquid of the adhesive composition contains an acryloyl group-containing component (acrylic polymer B) and a photopolymerization initiator, the active energy It has linear curability.

[Example 10]
A work handling sheet was obtained in the same manner as in Example 8, except that no ultraviolet absorber was used.

In addition, since the interfacial abrasion layer (adhesive layer) formed using the coating liquid of the adhesive composition contains an acryloyl group-containing component (acrylic polymer B) and a photopolymerization initiator, the active energy It has linear curability.

[Examples 11 to 20]
A release sheet (manufactured by Zhejiang Doming New Materials Co., Ltd., product name: "Transparent mesh release film P1S1 , thickness: 50 μm), work handling sheets according to Examples 11 to 20 were obtained in the same manner as in Examples 1 to 10.

When the release sheet is peeled off from the work handling sheet, the exposed surface of the interface abrasion layer is the surface corresponding to the release surface of the release sheet described above, that is, the surface having a plurality of grooves formed in a grid pattern. became. The groove width was 100 μm and the groove depth was 20 μm. In addition, the center-to-center distance between two adjacent grooves in the group of parallel grooves was 600 μm. These widths, depths and distances were measured using a digital microscope (manufactured by Keyence Corporation, product name "VHX-7000").

[Examples 21 to 30]
After melt-extrusion lamination of polyethylene resin (manufactured by Tosoh Corporation, product name “Petrothene 217”) on one side of high-quality paper with a basis weight of 110 g/m ² , it is passed between a cooling roll with a smooth surface and a pressure roll. , forming a polyethylene layer (thickness 30 μm). Further, a coating liquid of a release agent composition containing a silicone-based release component is applied to the surface of the polyethylene layer to form a coating film, and then the coating film is heated at 140° C. for 1 minute. Thus, a release agent layer having a thickness of 0.5 μm was formed. As a result, a laminate was obtained in which the woodfree paper, the polyethylene layer, and the release agent layer were laminated in this order. Subsequently, the obtained laminate was embossed to obtain a release sheet having a plurality of lattice-shaped projections on the release surface.

Work handling sheets according to Examples 21 to 30 were obtained in the same manner as in Examples 1 to 10, except that the above release sheets were used.

When the release sheet is peeled off from the work handling sheet, the exposed surface of the interface abrasion layer is the surface corresponding to the release surface of the release sheet described above, that is, the surface having a plurality of grooves formed in a grid pattern. became. The width of the groove was 35 μm and the depth of the groove was 17 μm. In addition, the center-to-center distance between two adjacent grooves in the group of parallel grooves was 200 μm. These widths, depths and distances were measured using a digital microscope (manufactured by Keyence Corporation, product name "VHX-7000").

[Comparative Example 1]
Except for using a release sheet (manufactured by Lintec, product name "SP-PET381031", the release surface is not uneven) in which a silicone-based release agent layer is formed on one side of a polyethylene terephthalate film with a thickness of 38 μm. obtained a work handling sheet in the same manner as in Example 1.

In addition, when the release sheet is peeled off from the obtained work handling sheet, the arithmetic mean roughness Ra (μm) and the maximum peak height Rp (μm) of the exposed surface of the exposed interface abrasion layer are measured as stylus type surface roughness. When measured using a meter (manufactured by Mitutoyo, product name "Surftest SV3000"), they were 0.03 µm and 0.05 µm, respectively. From these measurement results, the ratio of the maximum peak height Rp to the arithmetic mean roughness Ra (Rp/Ra) was calculated to be 1.67.

[Comparative Example 2]
A work handling sheet was obtained in the same manner as in Example 3 except that the release sheet used in Comparative Example 1 was used.

[Comparative Example 3]
A work handling sheet was obtained in the same manner as in Example 9 except that the release sheet used in Comparative Example 1 was used.

[Comparative Example 4]
A work handling sheet was obtained in the same manner as in Example 10, except that the release sheet used in Comparative Example 1 was used.

[Comparative Example 5]
A work handling sheet was obtained in the same manner as in Example 8 except that the release sheet used in Comparative Example 1 was used.

In addition, when the release sheet is peeled off from the obtained work handling sheet, the arithmetic mean roughness Ra (μm) and the maximum peak height Rp (μm) of the exposed surface of the exposed interface abrasion layer are measured as stylus type surface roughness. When measured using a meter (manufactured by Mitutoyo, product name "Surftest SV3000"), they were 0.03 µm and 0.1 µm, respectively. From these measurement results, the ratio of the maximum peak height Rp to the arithmetic mean roughness Ra (Rp/Ra) was calculated to be 3.33.

[Test Example 1] (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 2500 μm×2500 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 obtained in the above step (1), in which a plurality of chips are provided on the work handling sheet, the chips were irradiated with laser light through the work handling sheet using a laser light irradiation device. .

Specifically, the chip was irradiated with a laser beam through a work handling sheet using a laser beam irradiation device (manufactured by KEYENCE CORPORATION, product name “MD-U1000C”). The irradiation was carried out so as to fill a 2000 μm×2000 μm region in the center of the chip. At this time, the diameter of the laser beam spot was set to 25 μm, and the inner diameter of the ring formed as the locus of irradiation was set to 65 μm. Irradiation was performed on 10 chips (a group of 10 vertical chips by 1 horizontal chip) selected from a plurality of chips.

The irradiation was performed under the conditions of frequency: 80 kHz, scanning speed: 1000 mm/s, and irradiation amount: 25 μJ/shot.

(3) Confirmation of blisters and chip separation Regarding the work handling sheet and chips irradiated as described above, the presence or absence of blisters at the interface between the base material and the interface ablation layer in the work handling sheet, and the separation of chips from the work handling sheet. The presence or absence of detachment was confirmed, and suitability for laser lift-off was evaluated based on the following criteria. The results are shown in Tables 1 to 4 as results for "no UV irradiation".
○: The number of chips in which blister generation and detachment occurred was 8 or more.
x: The number of chips with blistering and detachment was less than 8.

(4) Pre-UV irradiation Of the work handling sheets produced in Examples and Comparative Examples, those having active energy ray curability were also evaluated as follows.

First, the work handling sheet alone was irradiated with ultraviolet rays from the substrate side surface (illuminance: 230 mW/cm ² , light intensity: 190 mJ/cm ² ). Then, using the work handling sheet, laser lift-off aptitude was evaluated in the same manner as in the above steps (1) to (3). The results are shown in Tables 1-4 as results of "pre-UV irradiation".

(5) Post-UV irradiation Of the work handling sheets produced in Examples and Comparative Examples, those having active energy ray curability were also evaluated as follows.

First, a laminate was obtained in the same manner as in steps (1) and (2) above, and laser light irradiation was performed. Thereafter, ultraviolet rays were irradiated from the surface of the work handling sheet on the substrate side (illuminance: 230 mW/cm ² , light intensity: 190 mJ/cm ² ). Subsequently, laser lift-off aptitude was evaluated in the same manner as in step (3) above. The results are shown in Tables 1-4 as "post-UV exposure" results.

As is clear from Tables 1 to 4, 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 handling semiconductor members.

REFERENCE SIGNS LIST 1 work handling sheet 11 interface ablation layer 12 substrate 13 groove 14 reaction area 2, 2' work piece 3 object 4 laser beam 5 blister 6 laser beam irradiation point

Claims (14)

a substrate;
A work handling sheet comprising an interfacial ablation layer laminated on one side of the base material, capable of holding a small work piece, and performing interfacial ablation by irradiation with a laser beam,
A work handling sheet, wherein the surface of the interface ablation layer opposite to the substrate is an uneven surface having unevenness. 2. A work handling sheet according to claim 1, wherein said uneven surface is a matte surface. 3. The work handling sheet according to claim 2, wherein the ratio (Rp/Ra) of the maximum peak height Rp to the arithmetic mean roughness Ra of said matte surface is 5 or more. 2. A work handling sheet according to claim 1, wherein said uneven surface is a surface having a plurality of grooves formed in a grid pattern. The width of the groove is 10 μm or more and 120 μm or less,
The groove has a depth of 5 μm or more and 50 μm or less,
5. The work handling sheet according to claim 4, wherein the center-to-center distance between two adjacent grooves in the group of grooves arranged in parallel is 50 [mu]m or more and 700 [mu]m or less. The work handling sheet comprises a release sheet laminated to a surface of the interfacial ablation layer opposite to the substrate,
The work handling sheet according to any one of claims 1 to 5, wherein the surface of the release sheet on the interface abrasion layer side has unevenness corresponding to the uneven surface of the interface abrasion layer. The work handling sheet according to any one of claims 1 to 6, wherein the interfacial abrasion layer is an adhesive layer. The work handling sheet according to any one of claims 1 to 7, wherein the interfacial ablation layer contains an ultraviolet absorber. The work handling sheet according to any one of claims 1 to 8, wherein the laser light has a wavelength in the ultraviolet region. The work handling sheet according to any one of claims 1 to 9, characterized in that when interfacial ablation is caused in said interfacial ablation layer, blisters are formed at positions where said interfacial ablation occurs. Any of a plurality of work pieces held on the surface of the interface ablation layer opposite to the base material is removed from the interface ablation layer by the interface ablation locally generated in the interface ablation layer. The work handling sheet according to any one of claims 1 to 10, which is used for selectively separating from. 12. The work piece according to claim 11, wherein the work pieces are obtained by singulating a work held on a surface of the interfacial ablation layer opposite to the base material, on the surface of the work piece. Described work handling sheet. In a work handling sheet comprising a base material and an interfacial ablation layer laminated on one side of the base material and having unevenness on the side opposite to the base material, on the surface of the interfacial ablation layer side a preparation step of preparing a laminate formed by holding a plurality of small work pieces;
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 on the interface ablation layer of the laminate to which at least one of the work pieces is attached to cause interface ablation at the irradiated position on the interface ablation layer. and a separating step of separating the small work piece existing at the position where the interface abrasion has occurred from the work handling sheet and placing the small work piece on the object. 13. In the preparation step, the workpiece pieces are obtained by singulating a workpiece held on a surface of the interfacial ablation layer opposite to the base material on the surface. The device manufacturing method described in .

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